Critical Care

A 56 year old wm , s/p AAA repair, in the ICU on the vent,with the following

•persistent hypotension despite fluids and pressors

•PCWP - 20

•CVP15

•hyponatremia

•hypoglycemia

Dx and management?

Adrenal Insufficiency

•Random cortisol level of less than 20µg/dl is suggestive

•Cosyntropin test - 250 µg of cosyntropin

•Check cortisol level at 30 minutes

•Failure to increase greater than 9 µg is diagnostic

•Administer Dexamethasone - it does not affect cosyntropin test

Label the axis on the following graph

Delivery dependentDelivery independent

X

Y

CaO2 = 1.34 x Hgb x SaO2 + ( 0.0032 x PaO2 )DO2 = CaO2 x C.OVO2 = C(a-v)O2 x C.O

Oxygen-hemoglobin disociation curve

What is P50 ?Factors that shift curve

to the right ?

Oxygen-hemoglobin disociation curve

P50P50 - the partial pressure of oxygen at which hemoglobin is 50% saturated with oxygen

AVP( ADH) is secreted in response to what?

AVP( ADH) is secreted in response to what?

Increased serum osmolality and hypovolemia

ADH increases water permeability and passive sodium transport to the distaltubule , allowing increased water reabsorption

Which of the following precludes a diagnosis of brain death?

A. Uremia

B. Hypothermia below 32.2 C

C. Systemic blood pressure of 70/40 mmHg

D. Hypercarbia with a PaCO2 greater than 60mm Hg with

no respiratory response

Answer: A, B, C

Brain death

• Def – Irreversible cessation of all functions of the brain, including brain stem

• 1st – Exclude reversible causes of coma, i.e. sedation, hypothermia, neuromuscular blockage, shock

• 2nd – Clinically unresposive to pain, absent brainstem reflexes and positive apnea test• Or flow study of blood to brain

A 45 year old female presents to the emergency room with nausea and vomiting and severe headache. She has been having these episodes frequently which last about an hour. A CT scan of the abd pelvis is obtained.

You suspect it is a pheochromocytoma.What is your work up?

Stop any interfering medications

Labetalol

Tricyclic Antidepressant

Levodopa or Methyldopa

Benzodiazepines

Labs:

Best studies

•Plasma Free Metanephrines

•Test Sensitivity: 99%

•Test Specificity: 89%

•Urine Metanephrines (24 hour collections)

•Test Sensitivity: 76%

•Test Specificity: 94%

Tests with lower efficacy (rarely used now)

Urinary VMA

Imprecise test

Plasma Catecholamines (Norepinephrine, Epinephrine)

•Test Sensitivity: 85%

•Test Specificity: 80%

Differential Diagnosis

Primary Aldosteronism

Carcinoid

Malignant Hypertension

Thyrotoxicosis

Menopause

Panic Disorder

Medication withdrawal (e.g. Clonidine )

PreoperativePreoperative

• IV Fluids• Alpha Blocker• Phenoxybenzamine

• start - 20mg per day• then increase by 10mg every 3 days• until pt has postural hypotension

• Prazosin - 1mg QID

• BetaBlocker• most pts do not need B-blocker• reserved for tachyarrhytmias• can exacerbate hypertensive crisis

You are about to do a laparoscopic cholecystectomy on a 25 year old female. The nurse anesthesist calls you into the room. She states that the patient has a temperature of 104.5 deg ,HR of 132 and high ETCO2 This

came on right after induction.

What is your most likely diagnosis

and management of this patient?

•↑ End tidal CO2 • Tachycardia• Fever 2°C per hour• Cyanosis• Mottling of skin• Tachypnoea• Arrhythmias• Rigidity• Sweating• Hypercarbia• Labile blood pressure• Intense masseter spasm

• Ice packs• Cooling blankets• Fans• Cold intravenous fluids• Intragastric, intracystic cooling• Peritoneal dialysis using cold diasylate• Extracorporeal cooling if equipment is available

• Core temperature• Arterial line and CVP line• Urinary catheter• ECG• Pulse oximetry & capnography• Blood gases• Serum glucose• Serum potassium• Blood for CPK• Urine for myoglobin

Signs and Symptoms Active Cooling Monitoring

Malignant HyperthermiaMalignant Hyperthermia

Terminate anaesthesia and surgery as soon as possibleTerminate anaesthesia and surgery as soon as possible

Hyperventilate with 100% oxygenHyperventilate with 100% oxygen

Give DantroleneGive Dantrolene

Transfer to ICU as soon as possibleTransfer to ICU as soon as possible

Malignant HyperthermiaMalignant Hyperthermia

DANTROLENE 2.5 mg/kg IV

Repeat as required at 5.10 min intervals to a maximum cumulative dose of 10 mg/kg.

Favorable response indicated by:

(a) fall in heart rate(b) abolition of arrhythmia(c) decline in body temperature(d) reduced muscle tone

•ARRHYTHMIASIf these persist despite Dantrolene give:PROCAINAMIDE 1 mg/kg/ml IV

Maximum dose: 15 mg/kg •ACIDOSISCorrection withSODIUIM BICARBONATE0.5 - 1.0 mmol/kg/dose IV

Repeated as necessary

•HYPERKALAEMIAControl if necessary using glucose and

INSULIN 0.1 units/kg in 2 ml/kg 50% dextrose IV

•URINE OUTPUTMANNITOL 0.5 - 1.0 g/kg(2.5 - 5ml/kg of 20% solution) and/orFUROSEMIDE 1 mg/kg IV

to maintain urine output (> 1 ml/kg/hr)

You are called to see a pt post-op in the ICU, this is You are called to see a pt post-op in the ICU, this is the tracing on the monitor. the tracing on the monitor.

Case 1. BP 70, HR160Case 1. BP 70, HR160Case 2.BP125/67 , HR86Case 2.BP125/67 , HR86

Atrial Fibrillation

Irregular P waves > 300/min, irregular ventricular rhythmAssociated Conditions:Associated Conditions: MI.HTN,hypoxia,Hyperthyroidism,electrolyte imbalance, pulmonary embolus

If Unstable ( Case 1)If Unstable ( Case 1) Cardioversion – 200 – 360 J

Initial TherapyInitial TherapyDiltiazem 0.25mg/kg , then 10-15mg/hrDigoxin 0.5mg , then 0.25mg Q2hrsEsmolol, procainamide, amiodarone

Subsequent therapySubsequent therapyProcainamide, Digoxin, anticoagulation

A 45 year old male with gastric outlet obstruction, has had an NG tube in for six days. His avg daily out put is 1500cc per day. On the sixth day you realize that the intern has not been replacing the NG output.

Inadequate or no replacement of nasogastric suctioning would result in what disturbance?

Hypokalemic,hypochloremic metabolic alkalosisHypokalemic,hypochloremic metabolic alkalosis

PARAD

OXIC

AL

ACID

URIA

1. Adequate volume status and hypotension refractory to inotropic agents

2. Distended neck veins, distant heart sounds, and hypotension

3. Hypotension, appropriate volume, atrial fibrillation with a HR of 40

4. Hypotension and low right and left atrial pressures

5. Adequate volume, no mechanical defects, hypotension

A. Inotropic agentsB. Cardiac pacingC. Fluid administrationD. PericardiocentesisE. Intraaortic balloon pump

Match the treatment

1. E2. D3. B4. C5. A

TNICU – PTD #2, Ex-lap, GradeII liver injury & splenectomy. R2 called at 0100 to see pt. RN states abdomen is tight. How do you work this up?

Abdominal Compartment Syndrome

should be suspected and sought for in any

multiple trauma patient who has undergone a period of profound shock and aggressive ressuscitation .

Clinically Clinically

•fall in urine output

• elevated central venous pressure.

•Increase peak airway pressure

•Decrease pulm compliance

The diagnosis confirmed by measurement of intra-abdominal pressure.

Pt with long cardiac history, PAC placed pre-op for large ventral hernia repair.

1st – CI 1.4 SVR 880 PWP 9 CVP 62nd – CI 1.6 SVR 1000 PWP 15 CVP11Vitals: BP 110/55, HR 128

Which Inotropic agent do you want to use and why?

MilrinoneDose: 0.3 – 0.75ug/kg/min 2.0 – 20ug/kg/min

Mechanism: Phosphodiesterase inhibitor B1,2,α

Cardiac contractility:

Heart rate: No change

Preload:

SVR:

Oxygen delivery:

Dobutamine

55 year old on trauma service with severe watery , foul smelling diarrhea, WBC 40,000, 15 bands. Colonoscopy showed the following.

Pseudomembranous Colitis

- Pseudomembranes compromised of fibrin, mucus and necrotic epithelial cells

- Mostly in rectosigmoid- Accessible to sig-scope- C.diff toxinis agent responsible- found in 90 -100% of Pts with Pseudomembranous

colitis- Mortality 20% - if untreated- Progression – perforation, toxic megacolon

TREATMENT:Flagyl – 250mg PO/IV Q 6 hrs – 7 – 10daysIf unsuccessfulVancomycin – 125 mg Q6 hrs ( PO only )

A 17 year old male, multiple A 17 year old male, multiple GSW, Blood loss ~ 2000cc, rapid GSW, Blood loss ~ 2000cc, rapid respiration, weak pulse, confused, respiration, weak pulse, confused, skin is cold and clammy and skin is cold and clammy and pale .pale .

What Class of hemorrhagic What Class of hemorrhagic shockshock ? ?

Classes of Hemorrhage

>35%4

25-35%3

15-25%2

<15%1

Resp. Volume

Resp. Rate

BPPulse

Pressure/ Strength

Pulse Rate

Vasocon-striction

Blood LossStage

• Average Blood Volume = 5 L

65 year old male , restrained driver in MVC, Vitals :BP 90/40, HR 110

A

B

C

D

What is the significance of SvO2?

Causes for an increase in SvO2 Causes for an increase in SvO2

decreased peripheral oxygen consumption decreased peripheral oxygen consumption

increased peripheral shunting ( e.g sepsis. cyanide toxicity , hypothermiaincreased peripheral shunting ( e.g sepsis. cyanide toxicity , hypothermia . .

An SvO2 of 75% is usually quoted as the normal value. An SvO2 of 75% is usually quoted as the normal value.

A range of 63-77% is acceptableA range of 63-77% is acceptable

under normal conditions, tissues extract 25% of the oxygen deliveredunder normal conditions, tissues extract 25% of the oxygen delivered

(the balloon at the end of the pulmonary artery catheter is inflated, the blood distal to the balloon stagnates, absorbs oxygen from the surrounding ventilated alveoli and becomes closer in saturation to arterial blood )

Mixed Venous Oxygen Saturation % - ConditionMixed Venous Oxygen Saturation % - Condition 77% - Sepsis, shunting, hypothermia, cell poisoning, wedged catheter 77% - Sepsis, shunting, hypothermia, cell poisoning, wedged catheter 66-77% - Normal range 66-77% - Normal range 60% - Cardiac decompensation 60% - Cardiac decompensation 55% - Lactic acidosis 55% - Lactic acidosis 32% - Unconsciousness 32% - Unconsciousness

20% - Permanent cell damage20% - Permanent cell damage

Dietary protein – (UNN + 4gm)

6.25

What equation is this?What does the 6.25 and 4 stand for?

1. Nitrogen balance

2. grams protein = 6.25(grams N)

1. 4 = factor for skin and GI losses

Copius irrigation and immediate application of

2.5% calcium gluconate gel.

Hydrofluoric acid