Westmead Obstetric Anaesthe

Obstetric Anaesthesia

Westmead Hospital

Westmead Anaesthesia 2010

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Obstetric Anaesthesia Westmead HospitalContents Page No. 1. Introduction 2 2. General Duties 3 3. Consent 3 4. Thromboprophylaxis 6 5. Regional analgesia for labour 8 6. Complications of epidurals 11 7. Subdural block 14 8. Accidental dural puncture 15 9. Post Dural Puncture Headache 17 10. Total Spinal 19 11. Drug related complications 19 12. Collapse of parturient 20 Amniotic fluid embolism 20 13. Caesarean section (CS) 22 Classification 22 Guidelines for preparation of parturient for CS (fasting antacid prophylaxis, 23 transfusion preparation) Spinal anaesthesia 26 Combined spinal epidural / epidural anaesthesia 27 General anaesthesia 28 Analgesia 30 14. Post CS prescribing 31 15. Anaesthesia for other operative procedures 33 16. Major obstetric haemorrhage 34 17. Post partum haemorrhage 35 Code Crimson 36 Mild / moderate PPH Mx flowsheet 37 Severe PPH Mx flowsheet 38 18. Cell salvage 39 19. Pre-eclampsia 40 Anaesthesia 40 Antihypertensive therapy 43 Fluid management 55 Severe eclampsia overall management flowsheet 56 20. Supervising midwife epidural top ups 60 21. GTN 61 22. References 62 23. Appendices - Mummy PACE 64 - Intralipid protocol 65 - Classification of Caesarean section 66 - Difficult intubation algorithm 67 - Remifentanil PCA (proposed) 68 - Guidelines for preparation of parturients for CS 73 - Admission to Birth Unit Acute Care 76Westmead Anaesthesia 2010 2

IntroductionThe purpose of these guidelines is to help anaesthetists, obstetricians and midwives. It is hoped that the guidelines will clarify principles of management of obstetric anesthesia at Westmead Hospital. This will lead to greater uniformity and consistency of practice, better teamwork and safety, leading to improved patient care. The guidelines are not rules, and helpful comments from all parties are welcomed.

General DutiesConsultants Consultants are on call from 0600hrs to 1730hrs and then from 1730hrs to 0600hrs. Depending on the day and the time of day they may or may not be in the hospital. They are responsible for the overseeing and training of the registrars. They are the first line of call in the anaesthetic management of privately insured obstetric patients. The obstetric consultants are also second line help after hours if extra anaesthetic help is needed and the general consultants have already been called in. Registrars There is 24hr cover by in-house anaesthetic registrars who carry the 08596 pager. They also cover pain management, trauma and cardiac arrest calls after hours and on weekends. Daily duties Handover of patients/problems from the on-call night/day duty anaesthetist/registrar. Both consultant and registrar should attend combined a daily board ward round at 0830hrs (0845hrs on weekends) with the obstetric team and midwives. If this is not possible you should get a handover from the lead midwife about the patients currently in Birth Unit and any anticipated admissions. Any patients in the obstetric acute care area should be reviewed. Get obstetric audit forms, which should then be completed during the day and returned to folder in Birth unit. Put your name and contact details on the white board. The registrar will generally be allocated a list to maximize theatre experience but their first priority is to cover the Birth Unit and associated tasks General points The obstetric anaesthetist is not an epidural technician. He/she is part of a team working closely with the obstetricians, midwives and paediatricians and should take an active role in clinical management decisions. Be prepared to discuss pain relief options with mothers in labour. Be prepared to supervise midwives in training for epidural top ups. Act professionally. Introduce yourself to the midwives/obstetricians if you or they are new. Always knock and wait for an answer before entering a delivery room.

Consent General points Signed consent is not necessary for regional analgesia in labour or anesthesia for caesarean section. However you should make a brief record of the risks/benefits that you


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have discussed with the woman since it is not unheard of for the woman to later deny that they were warned about a possible complication. If the patient is very distressed, keep explanations short and simple with more detail to be given once settled. Record this in notes (e.g. Only brief explanation before insertion as distressed). Always offer opportunity to ask questions and give honest answers. Any problems regarding consent must be referred to the consultant obstetric anaesthetist unless prevented by extreme clinical urgency. Epidural analgesia in labour is very safe and while it is important to inform patients of the risks involved it is worthwhile emphasizing how safe the process is to avoid unnecessarily distressing the patient. This could be couched as labour epidurals are very safe and we do about 1-2000 every year at Westmead with very few complications but like everything there are risks which include .. Regional analgesia in Labour You must tell the woman about the following risks. (The figures are only an aide memoire for discussion of relative risk so do not need to be included in every discussion unless further questioned by the patient). Hypotension (1in 50) Postdural puncture headache. If it occurs, there is an approximately >80% chance of blood patch relieving it. (1 in 200) Potential for failure, either complete or partial (chance of having to resite catheter = 5%) Risk of nerve damage including paralysis Temporary 1 in 1000 > 6months 1 in 13000 Severe injury including paralysis 1 in 250000 Risk of infection (abscess 1 in 50000, meningitis 1 in 100000) Risk of bleeding including haematoma (1 in 170000) You should consider telling the patient about Potential association of epidural with increased risk of instrumental delivery but no increased risk of Caesarean section (CS). Regional anaesthesia for Caesarean section You must tell the woman about risk of Hypotension and nausea Likelihood of sensation (touch +/- some pulling) during the operation Possibility of pain during the operation The occasional need for general anaesthesia Proposed administration of any analgesic suppositories Post dural puncture headache (~2% after 25G Whitacre needle, of whom will require blood patch) Other risks of neuraxial block as above You should consider telling the woman about Itching and shaking


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General anaesthesia for Caesarean section If a woman elects to have a GA in preference to a regional block she should be warned about the consequences of her decision upon neonatal sedation, blood loss and post operative pain (all increased). However this shouldnt be laboured, as it may be necessary to give a GA in the face of a failed regional block. A suitable form of words may be both methods are very safe, but an epidural / spinal more so than general anaesthesia. The mother who refuses operative delivery The mother who is mentally competent has the right to refuse treatment regardless of the consequences.


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ThromboprophylaxisThromboembolism is the leading cause of death in the UK (1) Labour Insertion and removal of a spinal or an epidural catheter (neuraxial blockade) is associated with an increased risk of spinal haematoma in the presence of anticoagulation. No LMWH for at least 12 hours BEFORE insertion or removal of epidural or spinal catheter (24hrs if therapeutic dose). No LMWH for at least 2 hours AFTER insertion or removal or epidural or spinal catheter. The most senior anaesthetist available should perform a block to minimize the risk of trauma, where there is a risk of significant anti-Xa activity. It is important to continuously monitor the patient post delivery for signs of spinal haematoma. Advise seeking help (and document same) if any symptoms of weakness, numbness, back pain or bowel and bladder dysfunction (onset may be delayed >24hrs). Any suspicion of spinal haematoma warrants rapid neurology/neurosurgical input. MRI is the radiological investigation of choice. Likelihood of resolution of neurological impairment decreases significantly after 8 hours. Obstetric Post Partum prophylaxis (2) 1. General- hydration and early mobilization 2. Enoxaparin (Clexane) 40mg SC daily until discharge for: All Caesarean deliveries and extended pelvic surgery All morbidly obese patients (early pregnancy BMI>40) All vaginal deliveries with 4 or more risk factors Risk factors for thrombosis Pregnancy Related General Age > 35yrs Pre-eclampsia Booking BMI >30 Immobility for 4days Parity 4 Labour >12hours Major intercurrent illness Forceps/ Ventouse use Major current infection Major blood loss Gross varicose veins Heterozygous for Factor V (Leiden) or Prothrombin Gene Mutation DVT of first degree relative There will be particular circumstances where intermittent pneumatic compression stockings (IPC) or TED stockings may be appropriate 3. Therapeutic warfarin (INR 2-3) or enoxaparin 40mg SC daily for 8 weeks for: Previous spontaneous VTE (i.e. no probable cause) Lupus anticoagulant or High Titre anticardiolipin Antibody AT lll, Protein C, Protein S deficiency Homozygous for Factor V Leiden or Prothrombin Gene Mutation or double heterozygote Paralysis of lower limbs


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Homozygous Sickle Cell Disease Note: Patients with previous VTE or thrombophilic state may require therapeutic or prophylactic anticoagulation during pregnancy and they should be assessed on a case-by-case basis.


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Regional Analgesia for LabourIdeally patient should have received and read information sheet below prior to consideration of epidural. (Currently this is not routinely done, but is something we are aiming for)

Epidurals for pain relief in labourIntroduction An epidural is the most effective form of pain relief for childbirth. It also allows you to remain awake and participate in the birth of your baby. Epidurals are usually straightforward to put in and very safe, but as with any medical procedure there is the possibility of complications. You and your partner should read this information sheet carefully so you can make a decision about having an epidural for your labour and delivery. You can discuss this further with your anaesthetist, obstetrician or midwife. What is an Epidural? An epidural is an injection of pain killing medicines into the lower part of your back. This stops the pain when you have a contraction. It is usually possible to stop the pain, but still allow you to move your legs and to push when the time comes for your baby to be delivered. Epidurals are put in by doctors who work in the Department of Anaesthesia at Westmead Hospital. How is the Epidural Performed? First you will have a drip inserted into a vein in your arm. This is to give you extra fluid to stop your blood pressure dropping. Next your anaesthetist will position you, either lying on your side or sitting up. Next your skin will be cleaned with an antiseptic solution and made numb with a small amount of local anaesthetic. This may sting, but only for a few seconds. The epidural needle will then be inserted. This is the most critical part of the procedure and it is important you stay very still. Once the needle is in the right place a very small plastic tube (catheter) will be threaded through the needle into the epidural space. During this you might feel some tingling or faint electric shocks in your back or legs which is quite normal. You should tell your doctor if you feel this. After this the needle is taken out and you are left with the flexible plastic tube in your back. This tube is used to give the pain killing medicine. The epidural can be topped up as often as needed through this plastic tube. You may lie comfortably on the plastic tube. What are the Risks? There are some side effects from epidurals which are common, but are only temporary. These include the following; Shivering and shaking Your legs may get heavy and feel numb Difficulty passing urine which may require a catheter to be inserted. This is common during labour even when epidurals are not used. Your blood pressure may drop. This may make you feel sick. It can be easily treated.


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Localised backache at the site of the epidural injection for 7 to 10 days. Epidurals are not linked with long term back pain.

There is the possibility of more serious, but very rare complications which you should know about. These include; Headache, which happens about once every 200 epidurals. Breathing difficulties, and a severe drop in blood pressure. Infection or a burst blood vessel where the epidural goes into the back. This is very serious, but is very rare. Nerve damage this is very rare.

Will it Affect my Labour? Modern epidurals have very little effect on your labour. They are thought to increase the total length of your labour by a very small amount but do not increase the chance of Caesarean section. In some cases an epidural may even speed up your labour. Considerations The time from request to attending mother for epidural should ideally not exceed 30min. If there is a request for an urgent epidural and you are busy elsewhere then you should consider asking for help. Establish the rationale for request for a regional block. Enquire as to when the woman was last examined. Sudden escalation of pain is often symptomatic of an imminent delivery (especially in parous women). Is there is a strong likelihood that the woman will proceed to an operative delivery? It is worth explaining to her that her analgesia for labour can be converted to anaesthesia for forceps or CS. Contraindications Absolute Uncorrected anticoagulation or coagulopathy Local sepsis Refusal Relative Imminent birth of baby Disease of nervous system Hypovolemia or ongoing antepartum hemorrhage Gross spinal deformity Severe fetal distress Systemic sepsis-T>38 not treated with antibiotics Special Considerations Thrombocytopenia Isolated platelet count of >75 is acceptable for a regional block, from 50-75 it should be discussed with the haematologist and the consultant anaesthetist. Below 50 is an absolute contraindication to a regional.


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In the presence of pre eclampsia the platelet function may not be normal and therefore block should not be done when count is below 75. In the presence of fulminant pre eclampsia with a rapidly falling count, it my even be prudent to have a cutoff of 100,000. Discuss with consultant if in doubt. Aspirin and NSAIDs do not appear to change risk of bleeding in regional block. Other anticoagulants (3) Anticoagulant Time to stop prior to regional block Ticlodipine 14 days Clopidogrel 7 days Glycoprotein Ilb/IIIa inhibitors Usually 24-48hrs Pre-eclampsia (PET) Patients with mild to moderate PET should have a platelet count within last 24 hours. Patients with severe PET should have FBC and clotting screen within last 6 hours. Maternal pyrexia Current opinion is that it is safe to administer a regional block in these patients. If patient is not on antibiotics administer antibiotics after discussion with the team and prior to siting epidural Haematological disorders In most patients there will be an increase in the coagulation factors level during pregnancy. There should be a management plan in the notes, otherwise liaise with the haematologist and obstetrician.

Technique 1. Obtain consent. 2. IV access ideally with a 16G cannula (with local anaesthesia, but a minimum of an 18G cannula). 3. IV Fluids should be commenced but there is no evidence for the role of a fluid bolus prior to insertion. Hartmanns should be 1000ml q6-8 hourly unless otherwise indicated (CVS disease etc) 4. Full aseptic precautions (gown, mask and gloves) +/- hat. 5. Catheter is inserted using a standard loss of resistance (LOR) technique. 3-5cm should be left in space. 6. FBC not required unless there is evidence of pre-eclampsia, antepartum bleeding has occurred, or anemia or thrombocytopenia is suspected. 7. Ideally epidural or CSE should be done at L3/4 or below. Be aware that most anaesthetists think they are going lower than they actually are BY 1-2 levels. 8. If CSE is done, the subsequent epidural dose should be given when the pain begins to reoccur after the spinal dose has been given. Be aware that the spinal needle may protrude 15mm beyond the epidural needle tip. 9. The usual technique is boluses of standard mixture of bupivacaine 0.125% + fentanyl 5mcg/ml to a maximum of usually 20mls. Top ups should be written as bupivacaine 0.125% + fentanyl 5mcg/ml of 15 20ml (5+5+5+?) q1hr as needed or similar. The use of incremental top ups decreases the risk of a high block. 10. An epidural infusion may be given instead of tops. Use the standard mix of bupivacaine 0.125% and fentanyl 2.5mcg/ml. 11. A combined spinal-epidural technique (CSE) can be used if the woman is extremely distressed.


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In this situation a spinal dose of 2mls of the standard epidural solution can be used (bupivacaine 2.5mg and fentanyl 10mcg) +/- fentanyl15mcg or bupivacaine 0.25% 1ml+ fentanyl 25mcg.

12. In case of suspected dural tap, the following can be used to differentiate saline and CSF. CSF Saline Temperature Warm Cold Protein Present Absent Glucose At least a trace Absent PH 6hours after the last top up. This must be followed up and reported to anaesthetist immediately. 5. Diet Light diet if no obstetric risk factors. Women with risk factors can drink water. 6. Continuous CTG monitoring will be commenced by midwives.

Complications of epiduralsWhilst siting epidural Blood in catheter Dural puncture Paraesthesia or pain Immediate Inadequate block Hypotension High blocks/subdural block/total spinal block Intravascular local anaesthetic local anaesthetic toxicity Delayed Dural tap and post dural puncture headache (PDPH) Neurological complications Drug related complications


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Blood in catheter Common problem. Best avoided by not inserting during contractions. Alternatively inject 5-10 ml of normal saline via Tuohy needle, hold, then feed catheter. Aspiration test reliable with low false negative of 0.2-0.4% (4). Withdraw about 1cm, flush with saline and try to re-aspirate. Repeat as necessary. If unable to leave sufficient catheter length in space resite catheter. Paraesthesia or pain Transient paraesthesia while threading catheter may be expected but if it persists you must stop threading and withdraw the needle and the catheter together. If there is pain on injection of local anaesthetic you should not proceed. Hypotension Usually defined as a drop in systolic BP of 20% from baseline. If uncorrected it may compromise uteroplacental flow. If BP25 Multiparity Obstructed labour especially in association with uterine stimulation Multiple pregnancy Short labours Treatment Supportive- ABC 100% O2, restoration of cardiac output correction of coagulopathy (early liason with haematology as large amount of blood products may be required) Early delivery of foetus


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Caesarean sectionClassification of Caesarean Sections All Caesarean Sections should be classified according to the severity of the primary indication. This will indicate to all personnel the degree of urgency of the operation, which should facilitate organisation: See summary page appendix CODE: CRITICAL For this group of women delivery needs to be immediate. The following category is not exclusive as clinical judgement may include others: Cord prolapse Lactate 4.9 Severe and unresolved fetal bradycardia CTG showing an abnormal baseline with reduced variability and late or atypical variable deceleration where a scalp lactate is unable to be performed and only when the obstetric registrar/CMO feels that the situation qualifies as Code Critical Placental abruption with pathological fetal heart rate pattern Failed assisted delivery with pathological fetal heart rate pattern Maternal cardiac arrest where CS may be indicated The midwife / obstetric registrar / CMO should call switchboard on 111 and identify CODE CRITICAL Caesarean Section Delivery Suite. This will notify: Obstetric registrar (08667) Neonatal registrar (08785) Duty anaesthetist (08460) Obstetric anaesthetic registrar (08596) (either duty anaesthetist or registrar will contact anaesthetic consultant on) Operating Suite NUM/TL (08780) Delivery Suite NUM/TL (27243) A general anaesthetic will often be required. However, topping up an existing epidural block is often as fast or faster than a GA and is safer for the woman. Close consultation between obstetric, midwifery and anaesthetic teams is paramount. The woman should be transported in a position to maximise placental circulation eg left lateral. IV fluids should be increased if in progress Due to the urgency of the procedure partners should not be present in theatre; they should be directed to delivery suite to await events CODE URGENT Urgent delivery of the fetus within 45 mins of decision (To be in theatre in 20 mins.): Pathological fetal heart rate pattern with scalp lactate 500mL), difficulty with haemostasis or the operation is > 60 minutes in duration the consultant should be called if not already present The uterus should not be exteriorised with a regional block without discussion with the anaesthetist.

Investigations Each patient should have recent FBC and blood group and hold (where indicated see above). Pre operative transfusion not usually considered at Hb>9g/dl. In cases at high risk of hemorrhage red cells should be cross-matched and delivered to theatre prior to starting anaesthesia.(see above) Urea and electrolytes only if specifically indicated. Diabetes Mellitus Routine pre-operative establishment of IV dextrose infusion is unnecessary for women with insulin dependent diabetes undergoing CS with regional block. They should be first on the list and fasted as above. BSL should be checked hourly. Providing the woman is able to take orally 4 hours post op then a fraction (e.g. half) the usual morning insulin dose should be given SC. Only if the woman


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has prolonged nausea and vomiting despite antiemetic therapy will i.v. dextrose and insulin need to be given. Women with gestational diabetes do not usually need insulin after delivery.

Fetal Resuscitation (14) In a non elective CS especially where code critical the following measures should be considered Syntocinon off Position- full left lateral Oxygen IV infusion of 1 litre of warm crystalloid Low BP: IV vasopressor Tocolysis : salbutamol, GTN 2 x 400mcg puffs sublingual - repeat after 1 min until contractions stop: max of 3 doses (not if abruption/ antepartum haemorrhage) Note: Turnaround times quoted by the transfusion laboratory are 30 minutes for a new specimen and 10 minutes for a Group and Hold already in the lab.

Anaesthesia for Caesarean SectionSingle shot spinal More rapid anaesthesia with less anaesthetic and a denser block is obtained with a spinal anaesthetic. Compared with an epidural there is less need for intraoperative analgesic supplementation/ conversion to GA. Should use small (24-27G) pencil point needle (Whitacre or Sprotte) as the incidence of headache is much less than with comparative Quincke type needles. If there is pain or paraesthesia in association with needle placement or injection, STOP and withdraw needle. Because it is recognized that the conus medullaris can extend lower than was previously recognized (and anaesthetists often think they are going lower than they are) spinal needles should never be inserted above L2/3 (6).

Principles of safe management Antacid regimen Avoid aortocaval compression at all times Phenylephrine, metaraminol or ephedrine should be drawn up with drugs for general anaesthesia readily available Establish i.v. infusion (Hartmanns or N saline, 16G cannula) All drugs which are to be injected into the subarachnoid space must be drawn up through a particulate filter. If fentanyl is used then ampoule neck should be swabbed with alcowipe before drawing up Check BP prior to starting. As a general rule maintain systolic arterial pressure above 100mmHg. Vasopressor phenylephrine 50-100mcg, metaraminol 0.5mg or ephedrine 3-6mg boluses should be given to maintain this. Drug doses Bupivacaine 0.5% heavy or plain 2.2 to 2.5ml Fentanyl 15-25mcg


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Morphine 100mcg Pre-term women (28-35 weeks) have a requirement for more local anaesthetic than those at term (>38 weeks), probably because of reduced caval compression and displacement of the dura by engorged epidural veins (7). Barbotage is not recommended but it is important to confirm that CSF can be aspirated during and on completion of injection of the solution. Increments of pure -agonist such as metaraminol (0.5mg) and phenylephrine (50100mcg) are preferable in the face of tachycardia (HR> 100). Alpha agonists tend to increase blood pressure with concomitant decrease in heart rate. There is less fetal acidosis when mothers receive phenylephrine compared to ephedrine (8). A phenylephrine infusion may be used for prophylaxis against hypotension. o Phenylephrine (1amp =10mg) diluted to 50ml with normal saline. o Start at 25ml/hr when spinal in and titrate rate to BP. Stop at end of procedure. If woman becomes pale and nauseated or starts yawning, assume that the BP has dropped and react accordingly. Don't wait for a BP reading. IMPORTANT- Bradycardia may result from the block spreading to the sympathetic innervation and, more ominously, a reflex response to decreased atrial filling. Bradycardia is an early warning that venous return is diminished and hypotension will follow. Prompt treatment with fluid, a vasopressor and possibly an anticholinergic agent should be given. Unlike epidural analgesia that may be patchy, spinal anaesthesia virtually guarantees complete sensory loss below the most cephalad level. Therefore all the dermatomes do not need to be tested. Anaesthesia should extend from T4 to S4 at time of delivery. A block to T4 should be confirmed and documented prior to starting surgery. The surgeon should also test the block with forceps at the line of incision prior to incision. In the event of inadequate block, don't attempt a second intrathecal injection without discussion with someone senior. Estimation of appropriate doses is difficult. If time permits insert an epidural catheter and titrate dose. In the event of fetal compromise, general anaesthesia is indicated. Post operative o Regular paracetamol 1gm qid IV/po (0600/1200/1800/2200hrs) and diclofenac 50mg tds po with food (0800/1200/1800hrs) (if no contraindications) for 3days o Mobilise normally. If headache occurs, assess and then manage as indicated. After intrathecal morphine, no further parenteral (IV/IM/SC) opioids should be routinely administered for 12 hours. Oral oxycodone (5-10mg q2h) is acceptable within this period. If inadequate then the acute pain service should be contacted. Naloxone 40mcg IV q5min to maximum of 5 doses should be charted for pruritis Spinal / epidural observation chart should be completed with need for 24 hours observation on the ward. Please fill in spinal audit forms in and place in tray in recovery

Epidural and combined spinal/epidural anaesthesiaIndications for epidural Epidural is in situ and used for labour analgesia.


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When a regional technique is preferable to general anaesthesia but spinal anaesthesia is relatively contraindicated e.g. cardiovascular disease.

Epidural top up Explain procedure and indications to patient. Emphasize that they will feel the sensation of pressure but not pain. Lignocaine 2% with adrenaline with fentanyl 5mcg/ml up to a total of approximately 20mls. Volume may be influenced by time since most recent top up in the Birth Unit. Majority of the top up should be done in theatre. Administration of anaesthetic dose in Birth Unit risks development of complications during the poorly monitored transit. No more than 10mls should be given in birth unit. Once top up is started do not leave patient. Epidural blocks may be patchy, therefore all dermatomes should be tested on both sides and the limits of the block and any missing segments should be documented. The obstetrician should test the block prior to incision. IV opioids such as fentanyl 20-50mcg increments can be used to control any breakthrough pain and should not be withheld for fear of foetal depression. Oxygen and nitrous oxide mixes may also be administered by the anaesthetic breathing circuit. Unrelieved persistent pain MUST be treated with a GA. If uterine relaxation is required (e.g. for delivery of 2nd twin) 50mcg increments of GTN may be given. (See methods of preparation in appendices). Hypotension does not seem to be a problem in women who are already venodilated by a regional block. A dose of morphine 3mg epidurally after delivery will give good postoperative analgesia. After epidural morphine, no further parenteral opioids (IM/IV/SC) should be routinely administered for 12 hours. Oral oxycodone (5-10mg q2h) is acceptable within this period (as above). If inadequate then the acute pain service should be contacted. Spinal / epidural observation chart should be completed with need for 24 hours observation on the ward. Combined spinal epidural Because it is now recognised that the conus medullaris can extend lower than previously recognised (and anaesthetists often misjudge the interspace), spinal needles should not be inserted above L2/3. Potential advantages The initial subarachnoid injection can be deliberately conservative to minimise the risk of a dangerously high block (e.g. in the morbidly obese, or women with difficult airways). In addition the haemodynamic consequences will be minimised. Catheter may be topped up in the case of prolonged surgery. Potential disadvantages Epidural catheter is untested because of block by spinal catheter

General anaesthesiaPre-operative Usual anaesthetic assessment should be done. Rapid sequence induction should be explained. If difficulty is anticipated then summon help before starting. Awake fiberoptic intubation should be considered if difficulty is anticipated. Sedation should not be withheld for fear of fetal depression. Ensure familiarity with difficult airway equipment and algorithm. BIS or entropy monitoring.Westmead Anaesthesia 2010 28

Induction of general anaesthesia for a code critical CS Woman should be transferred in left lateral position. Skilled assistant. Sodium citrate given. Free running drip with Hartmanns solution or 0.9% saline.16G IV cannula. Position woman on table with left lateral tilt of 15 and full monitoring. Optimise head and neck position for intubation. Oxygen 100% by close fitting facemask at sufficient flow to prevent rebreathing. Preoxygenate for 3mins or until end tidal oxygen concentration is 90%. Lightly apply cricoid pressure then administer induction agent (thiopentone 5mg/kg). Wait until eyelids drop then apply full cricoid pressure and give succinylcholine 100mg (more if weight >100kg). For mother with cardiovascular or cerebrovascular disease, do not withhold opioid at induction for fear of neonatal respiratory depression. Difficult intubations hints (Appendix 1) A smaller tracheal tube than predicted is often needed in obstetrics, especially if there is a history of URTI or pre-eclampsia, both of which dispose to laryngeal oedema. A McCoy blade can convert a Grade 3 view to a Grade 2 view. Do not maintain cricoid pressure at the expense of oxygenation. Remember women do not die from failure to intubate. They do die from prolonged attempts to intubate in the face of hypoxia and from unrecognised oesophageal intubation if in doubt, take it out and ventilate with bag and mask and proceed down difficult intubation algorithm Maintenance and reversal When satisfied with ETT placement, switch to automatic ventilation. Adjust fresh gas flow mix to 33-50% oxygen in N2O plus approximately 0.75 MAC of volatile agent. Remember the possibility of awareness at all times. Do not hesitate to increase the volatile as needed. Monitor with BIS or entropy. Only in the event of life threatening haemorrhage might discontinuation of volatile agent be considered as a measure to improve uterine tone, in such a situation, ketamine in 25mg increments could be used to maintain anaesthesia. Estimation of blood loss may be difficult because of Mixing of blood with liquor Mothers preoperative increased circulation blood volume and rapid contraction of uteroplacental circulation at delivery. Therefore significant loss can occur before development of tachycardia and hypotension. Extra vigilance is therefore needed. Observe for pallor, which may signal need for transfusion. Increments of non-depolarising relaxant should be given. After the umbilical cord has been clamped give morphine IV 10-20mg. Switch to 33% O2 if higher concentration used prior to delivery. At end of surgery reverse and use a nerve stimulator to confirm full recovery. This is particularly important if magnesium sulphate has been given.


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Immediate postoperative care Recovery All women who have undergone CS must remain in the recovery area for at least 30 minutes or until discharge criteria have been met. After general anaesthesia Supplementary oxygen should be administered until SpO2 is >95% breathing air. Before discharge from recovery ensure the following Cardiovascular and respiratory variables are acceptable and stable. Women are pain free Postoperative fluid, analgesia and LMWH charted

Analgesia Guidelines following Caesarean SectionWhere possible, the aim is to avoid leaving epidural catheters indwelling in order to reduce the low, but significant risk of epidural abscess formation. As a rule, single shot techniques such as single dose epidural or spinal morphine provide good analgesia where supplemental paracetamol and NSAIDs can be used. Where NSAIDs are contraindicated (e.g. PIH) it may be necessary to use a technique which allows for repeated dosage such as PCA. The alternatives for analgesia are as follows. 1. Epidural analgesia with epidural morphine post op The surgery can be performed under epidural block as per normal practice. 3mg of preservative free morphine (pre-packed syringes) is administered via the epidural catheter at the completion of surgery. Document this administration on the anaesthetic chart. The epidural catheter is then removed prior to transfer to Recovery and a band-aid placed over the site. Epidural catheter removal should be documented on an Epidural / Spinal Opioid Observation chart. Paracetamol 1gm IV is administered in theatre and thereafter 1gm qid for 3 days unless contraindicated 100 mg diclofenac is administered PR in theatre and thereafter 50mg PO tds for three days is charted on the regular medication chart. (Timed with meals 0800,1200, 1800hrs) Parecoxib does not have TGA approval for breast feeding women. However it is widely used and is most likely safe. The dose is 40mg post delivery instead of diclofenac suppository. Prescribe the following on the PRN medication chart; Oxycodone 5-10mg q2h for breakthrough pain Naloxone 40 mcg IV 5 minutely PRN x 5 for pruritis Antiemetics An Epidural / Spinal Opioid Observation chart should be completed. This chart has pre printed standing orders for respiratory and sedation observations, supplemental oxygen and management of complications. The APS registrar will need to be called if rescue analgesia is required. IV PCA opioid may then be started.


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2. "Single shot" spinal with intrathecal morphine The surgery can be performed under single shot subarachnoid block. A suggested mixture is 2.2-2.5 mls 0.5% bupivacaine (plain or heavy) 100 micrograms preservative free morphine +/- 15-25 micrograms fentanyl Paracetamol 1gm IV in theatre and thereafter 1gm qid for 3 days unless contraindicated 100 mg diclofenac is administered PR in theatre and thereafter 50mg PO tds for three days is charted for the ward (with food 0800,1200,1800hrs). Parecoxib does not have TGA approval for breast feeding women but is widely used and is most likely safe. Dose is 40mg instead of diclofenac suppository. Prescribe the following on the PRN medication chart; Oxycodone 5-10mg q2hr for breakthrough pain Naloxone 40 mcg IV 5 minutely PRN x 5 for pruritis Antiemetics An Epidural / Spinal Opioid Observation chart should be completed. This chart has pre-printed standing orders for respiratory and sedation observations, supplemental oxygen and management of complications. The APS will need to be called if rescue analgesia is required in which case IV PCA opioid may be started . 3. Post GA Ideally TAP block + Regular paracetamol (0600/1200/1800/2200) 0800/1200/1800hrs) for 3/7 Regular oxycontin 10mg bd for 2/7 PRN oxycodone 5-10mg q2h prn Antiemetics

and

diclofenac

(with

food

4. Intravenous PCA opioid IV morphine or fentanyl can be used when a CS has been performed under general anaesthesia and there is a contraindication to regular NSAIDs. This is prescribed in the same manner as for any general surgical patient having a PCA commenced. 5. Continuous epidural infusion If specifically indicated (e.g. severe PIH) a continuous epidural infusion can be continued postoperatively. Note that obstetric patients with epidural infusions can only be cared for in the following units. Birth Unit- acute care area A3C (Surgical High Dependency) Intensive Care Unit E3C (Neuro/Trauma High Dependency)

Prescriptions after Caesarean Section All cases unless contraindicated. Analgesia Diclofenac 100mg PR at end of operation (or parecoxib 40mg as above)


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Paracetamol 1gm IV at end of operation Regular diclofenac 50mg tds (with food 0800/1200/1800hrs) and paracetamol 1 gm qid (0600/1200/1800/2200)for 3 days If NSAIDs are initially contraindicated then the situation may be reassessed on subsequent days and may be started then (i.e. where concerns about perioperative bleeding). Contraindications to NSAIDs Hypovolemia or continuing bleeding (risk of renal hypoperfusion) Preexisting renal impairment (including poor urine output in pre eclampsia). If diclofenac is withheld, review after 24 hrs and reconsider. Coagulopathy Asthma with history of sensitivity to NSAIDs Peptic ulceration Hypersensitivity Antiemetic Ensure that antiemetic prescribed. This should include ondansetron 4mg IV/SL/O q8h +/metoclopramide 10mg IV q8h +/- droperidol 0.5mg IV Antipruritic Naloxone 40mcg IV q5min prn to max of 5 doses if had neuroaxial opioids. Intravenous fluids Bear in mind that up to 2 litres will have been given in the course of a regional block and that uncomplicated CS should be drinking within a short time. Particularly in pre eclampsia be aware of potential fluid overload. The Syntocinon infusion and a further 2000ml of fluid should ordinarily suffice. More fluid should only be prescribed due to clinical need (haemorrhage, protracted vomiting). Discuss with the surgeons regarding the need for a post delivery syntocinon infusion (it may not be required especially in elective cases). If needed it is generally 40units in 1000ml of Hartmanns run over 4 6 hours.


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Anaesthesia for other operative proceduresApart from Caesarean section, you may be asked to provide anaesthesia for Insertion of cervical suture Trial of instrumental delivery Suturing of third degree tears Delivery of retained placenta Evacuation of products of conception Laparotomy Regard every woman from 16 weeks of pregnancy until 2 days post-partum, or any woman with symptoms of gastro-oesophageal reflux as having a stomach full of acid contents. All women should have H2 antagonists e.g. ranitidine 50mg ivi (if time permits) and antacid premedication, and if GA chosen, induction by rapid sequence induction. The minimal incidence of headache after pencil point spinal needles means that most women can routinely be offered spinal anaesthesia (unless contraindicated e.g. by coagulopathy or hypovolemia). The above procedures should be performed in the operating theatres. Beware of any forceps/ vacuum delivery that turns into a Code Critical emergency CS. If there is any chance of a CS becoming necessary, transfer to theatre and ensure adequate block to T4 prior to procedure starting. The risk of precipitating premature labour is attributable to surgical activities rather than anaesthesia. Opioids and paracetamol are the mainstay of postoperative analgesia. NSAIDs should be avoided owing to unknown fetal effects. The baby should be monitored in recovery (with CTG) and in the ward in the post operative period. Retained placenta/ products of conception Any woman who is pale, tachycardic and hypotensive after delivery must be considered to have lost a substantial amount of blood until proven otherwise 2.0-2.5ml plain or heavy bupivacaine 0.5% should ensure cold sensation blockade to T10 and maternal intra-operative comfort. Hypotension in the course of regional anaesthesia for retained placenta is related to the extent of maternal blood loss rather than block height. Laparotomy Pregnant women not uncommonly present with abdominal pain and require such procedures as appendicectomy or ovarian cystectomy. These are best performed under GA. Avoid NSAIDs.


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Major obstetric hemorrhageObstetric hemorrhage can be primary or secondary (associated with coagulation failure) or both. Secondary Primary Uterine atony (70%) Pre-eclampsia/ HELLP syndrome Placenta praevia Intrauterine sepsis/ septicemia Retained placenta/ products of conception (10%) Amniotic fluid embolism Genital tract trauma (20%) Preexisting coagulopathy Uterine rupture Incompatible blood transfusion Uterine inversion Retained dead fetus

Placental abruptionPremature separation of a normally situated placenta. Intrauterine death implies that a large abruption has occurred, as sizable covert haemorrhage can occur into the uterine myometrium. Coagulopathy can be expected in to of women in whom intrauterine death has occurred, but is most unlikely if the fetus has been delivered alive. As soon as massive blood loss is evident, assumed or can be predicted Notify senior anaesthetist, obstetric team, senior midwives. Give high concentration of oxygen to mother. 2 large bore cannulae (16+G). Blood for FBC, coagulation screen and fibrinogen, cross match. Order minimum of 6 units of blood. Blood group and presence of abnormal antibodies should be available from notes. If urgent give uncrossmatched Group O Rh negative blood. Cell salvage should be considered in cases of actual or anticipated major haemorrhage. Initial volume should be 2 litres of warm N saline or Hartmanns followed by colloid until blood is available. There is increasing evidence of the importance of keeping woman warm and warming IV fluids on the basis that hypothermia impairs coagulation (29). Ideally blood should be administered through a blood warming device. High pressure infusion devices must be available. Additional calcium is only rarely required. While blood is gushing out, it is useless and wasteful to give clotting factors or platelet replacements. Once surgical haemostasis has been more or less achieved, continuous oozing is quite possibly due to blood factor deficiencies. Further samples of blood should be sent at this time, and there should be close liaison with the haematology registrar on call (p27150). See massive transfusion protocol.

Uterine inversionUterine fundus becomes displaced, usually in 3rd stage of labour. It is classified as complete if the fundus passes through the cervix. Haemorrhage can be severe and the clinical signs of shock can be out of proportion to the blood loss. A reflex bradycardia can be mediated by traction on the ligaments supporting the uterus.


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Post partum Haemorrhage (PPH)PPH is a common potentially life threatening complication of both vaginal and Caesarean birth and is a major cause of morbidity and mortality worldwide. UK data suggests there are 60 near misses for every PPH maternal death (30,31). Primary PPH is blood loss within the 1st 24hrs after delivery which involves 1. Blood loss 500ml - 1000ml (minor PPH) 2. Blood loss 1000ml (severe or major PPH) - Anaesthetist must be notified 3. Any blood loss considered excessive by staff and which causes haemodynamic change to the woman. Risk factors The major causes are related to the 4Ts- Tone, Trauma, Tissue, Thrombin (32) o Atonic uterus (70%) o Genital tract trauma (20%) o Retained placental tissue (10%) o Primary coagulopathy 1500ml OR Woman that continues to bleed and is symptomatic regardless of volume lost. This code may also be used for situations such as rupture ectopic pregnancy. In the above situation all the same staff are notified as with a code critical LSCS but allows theatre to set up for management of major blood loss including laparotomy rather than setting up for LSCS. Preparations should be made in theatre for managing this.


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Flowsheets for combined anaesthetic / obstetric management of PPH.Flow Chart for First Line Treatment for Postpartum Haemorrhage 500 1000 mL (managed by Obstetric team)Call for HELP: 1. Call Team Leader O&G REG 2. Assign a midwife / RMO for communication & documentationResuscitation (per clinical situation): 1. Insert one or two 16G or 14G cannulae depending on clinical situation 2. If loss rapid or approaching 1000mL, collect blood for: X match - 6 units pack cells, 4 units FFP FBC, EUC Coagulation screen - fibrinogen, PT, APTT 3. Monitor & record BP (automated machine if available) & pulse every 10min 4. Give O2 via mask 15 L/min if pulse rate > 100/min or SBP < 90mmHg

Management of Atony (70% of PPH) 1. Keep woman WARM 2. Massage fundus Syntocinon (oxytocinon)40units in 1000mL Hartmanns run at 250 mL/hr Syntometrine 0.5mg I.M or 0.125mg slow IV (if no history of hypertension or peripheral vascular disease) Rectal Misoprostol 800 microgm(4tabs) or Cervagem 1mg Digitally explore uterine cavity to evacuate clots if bleeding continues despite seemingly good contraction Consider uterine inversion if uterus difficult to palpate 1. Bimanual compression if loss worsens and proceeding to OT

Volume replacement 1. 1000 mL crystalloids stat via each cannula (N/S, Hartmanns) 2. Maintain fluids according to blood loss and maternal symptoms. Aim to replace 3x blood loss with crystalloids. After 3000mL of crystalloids, consider blood transfusion. 3. Colloids rarely needed except in pre-eclampsia

Management of Retained Tissue (10% of PPH) 1. Re-examine placenta for completeness 2. Review USS reports for presence of succenturiate lobes 3. If cotyledons retained proceed to OT

Management of Coagulation Problems (1% of PPH) Re-assess coags every 30 mins if bleeding is ongoing (see next flow chart).

Management of Lacerations (20% of PPH) 1. Obtain light source, vaginal retractor, sponge holding forceps & assistance 2. Review perineum, vagina & cervix thoroughly 3. Consider uterine rupture (rare) 4. Consider need to go to OT


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Flow Chart for Failure to Control Bleeding And Severe PPH ( > 1000mL) Additional to first linemanagement

Call for HELP: 1. Notify: Consultant O&G if not present Consultant anaesthetist Consultant haematologist Blood Bank Operating Theatre Emergency call 111 to PACE Team if help required (especially if patient on postnatal ward)

Proceed to OT for EUA and further Surgical Measures: 1. Prostin F 2 alpha injected intramyometrially by medical officer (up to 3mg). Note: in rare situations where OT is not available and a consultant or senior registrar orders and administers Prostin F 2 alpha, it can be given in the delivery suite. However, because of rare (1:1000) cases of cardiac arrest, should only be given without ECG monitoring in emergency circumstances where risks of delay exceed risks of administration. 2. Remove any retained products 3. Repair lacerations 4. Tamponade packing, RuschBakri/Sengstaken balloon catheter 5. Laparotomy 6. Ligation of arteries (uterine, ovarian at cornua, internal iliac) 7. Haemostatic suturing of anterior and posterior uterine walls (B-Lynch and variants) 8. Hysterectomy 9. Radiological embolisation if available 10. Prophylactic antibiotics

Resuscitation: 1. Obs now every 5 min 2. Temperature every 30mins 3. Repeat blood tests every 30min 4. Consider insertion of central line to guide fluid replacement 5. Continue resuscitation and monitoring: ECG, pulse oximeter 6. Continue bimanual compression while awaiting definitive procedures

Volume replacement 1. Give blood through blood warmer & pump set without a microaggregate filter 2. Anticipate coagulation problems and manage as per massive transfusion guidelines. (see appendix)

VTE prophylaxis after major PPH is of critical importance, especially if surgery took place. This is a very high-risk group and IPCs (calf compressors) must be commenced in OT and continued postnatally for 5 days or until full mobilisation. Westmead Anaesthesia 2010 38

Cell salvageIndication in obstetrics Actual or anticipated major haemorrhage during CS e.g. Placenta praevia with risk factors for placenta accreta CS in the patient with objections to donor blood transfusion Difficulty in the provision of cross-matched blood e.g. rare blood type Should transfuse any salvaged blood using the same guidelines as with homologous blood. I.e dont give it just because it is there. Contraindications Presence of infection or malignant tumours in the operative field. Sickle cell disease (but not trait) Recovery of blood from vagina (potential for bacterial contamination from normal resident bacteria). The use of cell salvage is a clinical decision and each case should be considered individually. In some situations the benefit to the patient may outweigh the risk of usual contra-indications, particularly in situations of life threatening haemorrhage. Rules for use in obstetrics Wherever possible the use of cell salvage should be discussed with the patient in advance and this should be documented The cell salvage machine operator must have undergone training, be competent and understand cell salvage in the obstetric situation Aspiration of amniotic fluid into the cell salvage collection reservoir must be minimised. This can be done by the use of a separate sucker for initial removal of amniotic fluid. Salvaged blood for reinfusion must be clearly labeled with the patients name, hospital number and use by time and must be prescribed by medical staff, according to standard operating procedures. Salvaged cells should be infused within 6 hours or the start of the collection through a leucocyte depletion filter to minimise the risk of infusing fetal cell debris. Transfuse as per normal guidelines i.e. only as indicated and not just because salvaged blood is there.


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Pre-eclampsiaSummary1. Hypertension in pregnancy is common and affects approximately 7% of

pregnancies.2. It is associated with increased maternal and perinatal morbidity and mortality. 3. Hypertension in pregnancy is defined as a BP of 140/90 or greater. Severe 4.

5. 6. 7. 8. 9.

10. 11. 12.

13. 14. 15. 16.

17. 18.

hypertension is defined by a BP of 160/110 or greater. For acute lowering of BP in severe cases, intravenous hydralazine is the drug of choice (5 mg every 20 min for 4 doses which can be repeated after 2 hrs). Controlled reduction of BP is preferred antenatally to avoid sudden reduction in placental perfusion. Aim for SBP 140-150 and DBP 90-100mmHg at a rate of 1020mmHg q10-20min (Level 4) (32) Continuous CTG monitoring is essential with use of parenteral antihypertensive medication. These patients are often complex. Early and ongoing communication between anaesthetists, obstetricians +/- medical teams is essential. One to one midwifery care is essential in severe cases. Magnesium sulphate infusion is the drug of choice for treatment of eclampsia and in prophylaxis against seizures in severe pre eclampsia (Level1). Main objective of management must be safety of the mother. While oliguria is commonly associated with severe cases it is not life threatening and care must be taken to avoid fluid overload and pulmonary oedema. Adequate urine output is 80 mL in 4 hours. Pulmonary oedema and hyperkalemia are life threatening complications and early transfer to ICU/appropriate high dependency bed is indicated. Fluid intake (oral + intravenous) is limited to 85mL/hr (includes MgSO4 and IOL fluids) in moderate and severe pre-eclampsia. For IOL (induction of labour) or augmentation in moderate and severe preeclampsia use 40U Syntocinon/1,000mL run at 4 - 60mL/hr rather than 10U Syntocinon/1,000mL run at 15 240mL/hr. While delivery is always appropriate for mother with pre eclampsia, it may not be for infant. Active management of the third stage is recommended and Syntocinon should be used. Syntometrine or ergometrine should not be given. In severe cases close monitoring is indicated for 24-48 hrs postpartum including blood tests every 4-6 hrs initially. Venous thromboembolism is a major risk in these women. Intermittent pneumatic compression devices (IPCs / calf compressors) should commence on the operating table and LMW heparin can begin shortly after delivery. Both should continue until full ambulation. NSAIDs should be avoided for 24 hours postpartum. After 24 hours if the renal function normal and there is good urine output, NSAIDs can be used. A clear management plan should be documented and should include monitoring of a. Blood Pressure i. Record every 1. 5 minutes for 20 minutes while giving intravenous antihypertensives, then hourly 2. 15 minutes with severe hypertension (SBP 160 or more, DBP 110 or more) until SBP at or below 160 and DBP at or below 100 for 2 readings and then every 30 minutes


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b.

c.

d.

e.

f.

3. 30 minutes while on MgSO4 ii. Aim to keep SBP at or below 150, DBP at or below 100 iii. Lower BP slowly if undelivered and monitor fetus continuously when giving intravenous antihypertensives iv. Antihypertensive therapy and dosage should be clearly recorded Neurological symptoms and signs which may indicate increased likelihood of eclampsia. i. Enquiries should be made about headache and blurred vision at least once a shift in severe pre-eclampsia patients not on MgSO4. ii. Reflexes and clonus should be assessed once a shift (by midwife) in women with severe pre-eclampsia not on MgSO4. iii. Reflexes should be assessed every hour when on MgSO4 Pulmonary oedema symptoms i. Continuous pulse oximetry. Obstetric registrar to review if SaO2 < 95% and to 1. Consult anaesthetic or medical team 2. Auscultate lungs +/- check JVP 3. Check CVP if in situ 4. Review fluid balance 5. Consider frusemide 20mg i.v. stat 6. Consider CXR 7. If clinical features inconsistent with pulmonary oedema, consider other causes of dyspnoea such as pulmonary embolus or amniotic fluid embolus ii. Difficulty with breathing should be assessed at any time Fluid balance i. Close review of fluid balance is required with urine output recorded hourly ii. Fluid input including induction of labour fluids, MgSO4 fluids and oral fluids should not exceed 85mL/hour in severe pre-eclampsia patients managed in delivery suite. iii. CVP can be helpful in complicated cases. There is disparity between CVP and PAWP at CVP 5mmHg when the PAWP may be considerably higher. Volume expansion may be undertaken if CVP 5mmHg but should be considered full if CVP > 5mmHg. MgSO4 Toxicity Symptoms and Signs. The following are checked regularly: i. Every 30 minutes 1. Blood pressure 2. Pulse 3. Respiratory rate (normal > 10 / min) 4. Pulse oximetry (normal > 95% on room air) ii. Every 60 minutes 1. Patellar reflexes (normal is elicitable) 2. Urine output (normal 80mL / 4hours) iii. Excessive sedation should be watched for iv. If concerned about toxicity, check serum magnesium level from arm without the infusion (therapeutic range 1.5 3.5 mmol/L) Other organ impairment (liver, renal, coagulation etc) should be checked every 6 hours during labour and in the first 24 hours after delivery. Deterioration in EUC, uric acid, LFTs, platelets and coags can occur for 24 48 hours after delivery, sometimes to serious levels.


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19. Post-natal control of BP sometimes requires introduction of nifedipine 20mg p.o.

b.d. in addition to or in lieu of usual antenatal medications of methyldopa and oxprenolol. Consultant or senior registrar to authorise. Watch closely for hypotension if patient also on magnesium sulphate.

PurposeThe purpose of this practice is to outline the management of a woman in Birthing Unit with a hypertensive disorder of pregnancy as this presents major risks to the woman and fetus. The management centres on controlling the disorder to prevent maternal morbidity including intracerebral haemorrhage and pulmonary oedema, and to prolong the pregnancy for fetal maturation. Delivery is indicated if the process cannot be controlled in the woman or the risks to the fetus of delivery are less than the intrauterine hazards. The definitive treatment is delivery. Pre-eclampsia (PE) is a multi-system disease, where end-organs (e.g. cardio-vascular, renal, central nervous, hepatic, coagulation and placenta) may be affected to a greater or lesser extent. Careful assessment of each such end organ is essential for optimal management. Therefore, the womans care is generally multidisciplinary with ongoing monitoring and treatment undertaken by experienced midwifery, obstetric and anaesthetic staff. This aims to decrease the associated maternal and neonatal morbidity and mortality.

ClassificationThe classification of hypertensive disorders of pregnancy is as follows: Gestational hypertension Preeclampsia Chronic hypertension Pre-eclampsia superimposed on chronic hypertension (see educational notes)

Practice/ Procedures PrinciplesAssessment Assessment of the woman with hypertension in the Delivery Suite by the obstetric registrar should be made in consultation with the senior obstetric registrar on duty or the CMO responsible. The anaesthetic team should be made aware early of any patients that may involve both teams.

Blood pressure monitoring: Where an automated device is preferred for use, the blood pressure should be initially compared with that from an auscultatory device and the difference considered with future readings. The womans right arm should be used A large cuff should be used if the upper arm measures > 33 cms Diastolic should be estimated at Korotokoff V (i.e. when heart sounds disappear)

Assessment of other systems. Assess: Deep tendon reflexes and look for the presence of clonus Presence of right upper quadrant/epigastric tenderness/nausea and vomiting


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Presence/extent oedema especially non dependant (face and arms) Presence of headache/ visual disturbances

Maternal investigations - Initial investigations should include: Urinalysis and possible commencement of 24 hr urine collection MSU to exclude infection if leucocytes and / or nitrites present Urine output must be accurately monitored and recorded Blood should be collected for: Full blood count including platelets Urea, creatinine and electrolytes Urate > 0.xy mmol/l is pathological (where xy = the gestation in weeks) Liver Function Tests (LFTs): serum AST and ALT should be 5 cm H2O

SEIZURE PROPHYLAXIS / MANAGEMENT WITH MAGNESIUM SULPHATE The management principle is to reduce the associated hyperreflexia by using magnesium sulphate (MgSO4) as a central nervous system depressant (by reversing cerebral vasoconstriction) and thereby reducing the incidence of seizure.


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Magnesium sulphate is indicated for treatment of eclampsia (see below) and for prophylaxis against seizures in severe preeclampsia. It is only to be commenced after consultation with Obstetric consultant. Intravenous MgSO4 should only be administered in the Birth Unit (preferably in the Acute Care Area) or other high dependency care areas (including OT) with continuous midwifery/nursing care. MgSO4 should be administered as a continuous infusion via a volumetric pump A flask of magnesium sulphate 50 grams in 1 litre sterile water (preloaded by Pharmacy and kept in the Birth Unit medication refrigerator) should be used with the following regime: Loading dose of 4 grams (80 mL) should be infused over 30 minutes followed by Continuous infusion of MgSO4 at a rate of 1 gram per hour (20mL per hour) If convulsions occur, 2 grams to 4 grams (40 mL to 80 mL) of the continuous infusion solution of magnesium sulphate should be given as a bolus dose over not less than 510 minutes in addition to maintenance dose. If infusion is ceased and needs to be recommenced assess deep tendon reflexes. o o if reflexes brisk give loading dose 4gm (80mL) as above, then infusion at 1gm/hr (20mL/hr). if reflexes absent, simply restart infusion at 1gm/hr (20mL/hr)

The infusion should be continued at least 24 hours after delivery or after the last seizure or after commencement if started post partum. If side effects are experienced and are bothersome the infusion rate should be reduced to 10mL/hr and registrar informed.

Common maternal side effects: nausea, sensation of pain and warmth in arm, flushing of hands, face and neck Signs of maternal toxicity: Loss of patellar reflexes Respiratory rate < 10 / min Slurred speech, weakness, feeling extremely sleepy, double vision Muscle paralysis Respiratory / cardiac arrest

Potential fetal effects: Decrease in FHR baseline and variability as well as in fetal breathing movements. Potential neonatal effects: Hyporeflexia and transient decrease in tone or neck extensors, weak or absent cry


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Observations with Magnesium Sulphate Therapy The following observations should be attended whilst MgSO4 infusion is in progress: Every 15 minutes o Patellar reflexes for first hour after loading dose or bolus. Thereafter hourly.

Every 30 minutes o o o o BP Pulse Respiratory rate cease infusion if < 10/min. Inform registrar. Check serum magnesium level urgently. Pulse oximetry inform registrar if < 95% on room air, 97% on O2 (NOTE: 170/110 mmHgBP 150-170/100-110

Recheck BP every 5 mins If sustained over 15 mins: Undelivered No prior crystalloid Delivered OR prior crystalloid

Recheck BP every 15 mins If sustained over 45 mins:

Undelivered No prior crystalloid

Commence 500 mls crystalloid to run over 60 mins

HYDRALAZINE 5 mg IV

Commence 500 ml crystalloid to run over60 mins

BP 160/105 mm Hg

Recheck BP after 15 mins

BP < 160/105 mm Hg

Recheck BP every 15 mins

Hydralazine 5 mg IV every 20 mins until either

1. MAP > 160/105 mmHg & heart rate > 120 / min or 2. 20 mg hydralazine given (4 doses)

Consider magnesium sulphate infusion Discuss with consultant and anaesthetist


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Fluid management in severe pre-eclampsiaTotal fluid intake - 85mL/hr (including MgSO4/IOL fluids)

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