Download - 2005 Pedi Regional -- Handout

8/13/2019 2005 Pedi Regional -- Handout

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Pediatric Regional Anesthesia

Caudal Anesthesia

Amr Abouleish, MD, MBA

University of Texas Medical BranchGalveston, Texas


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Pediatric Regional Anesthesia

How do children differ from adults?

Why do regional anesthesia and analgesiain children?

Caudal Anesthesia and Analgesia Test dose

Single dose local anesthetic or morphine

Continuous Caudal/Epidural Infusion Spinal Anesthesia (if we have time)


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How do children differ from

adults?

Psychologically and Parents

Physiology

Pharmacology Anatomy


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Physiology

Postoperative apnea in former premature

infants

Implications

Immature CNS and BBB

Regional alone decreases risk


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Pharmacology

General and Implications Distribution

CSF Volume

Total Body Water

Protein Binding

Clearance Liver

Renal

Local Anesthetics Opioids


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Approximate CSF Volume

Cote, A Practice of Anesthesia for Infants and Children

0

2

4

6

8

10

12

14

16

Premature Full Term Child Adult

ml/kg


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CSF Volume: Implications

Dosage of Drugs

tetracaine 1 mg/kg +

epinephrine for spinal

bupivacaine 0.5-1.0

ml/kg for caudal

Duration of action

e.g. Spinal Tetracainewith epinephrine

0

50

100

150

200

Infants Adults

minutes



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Total Body Water

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

ICF

ECF

%o

f

bodyweight


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Protein Binding and Clearance

Protein binding decreased at birth

Albumin and -glycoprotein levels decreased

Adult levels at 1 year of age

Clearance

Liver: Phase I & Phase II decreased

Renal: GFR 30% of adult

Adult levels by 3-5 months of age

Clin Pharm, 14:189, 1988


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General Pharmacology

Implications

Increase CSF VolumeIncrease dose &

decreaseduration

Increase Total Body WaterIncrease IV

dose,

decrease toxicity

decrease Protein BindingIncrease

%drug availableIncrease toxicity

decrease ClearanceIncrease t1/2

Increase toxicity


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Local Anesthetics

BE CAREFUL with repeated dosing andinfusions

Neurologic symptoms > cardiac symptoms

May not be able to illicit early neurologic symptoms insmall children

First sign may be a grand mal seizure

Case Reports of Toxicity with Infusion

4 children, 1 neonate Children all presented with grand mal seizures

Neonate presented with cardiac arrest

Anesth Analg, 75:164, 1992; Anesth Analg, 75:284, 1992; Anesth Analg, 75:287, 1992


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Opioids

Morphine's t1/2 in neonates twice of adults

Approaches adult by 2-4 months

Implications: BE CAREFUL with opioids

and infants Recommendation for opioids

For IV,


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Anatomy



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Why Regional Anesthesia and

Analgesia in Children?

Regional Anesthesia only

Combined Regional and General

Anesthesia

Contraindications


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Regional Anesthesia Only!

Reduce risk of postoperative apnea in formerpremies Regional anesthesia alone will reduce risk of

postoperative apnea

Still need to monitor overnight

Techniques Caudal: 0.25% Bupivacaine (1ml/kg) + Clonidine (1 mcg/kg)

Spinal: Tetracaine, surgical anesthesia for 60-90 minutes

In other age groups, difficult to do regionalalone

Anesthesiology 101:A1470, 2004


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Combined Regional and General

Anesthesia

Usually regional anesthesia forpostoperative analgesia

Types

Single dose caudal

Continuous Epidural/Caudal Infusion

Peripheral nerve blocks

Field blocks Local infiltration


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Combined Regional and General Anesthesia:

Indications Malignant Hyperthermia

Avoid need for opioids Sedation or respiratory depression

DSU patients

Better analgesia?

for CEI Pulmonary disease (cystic fibrosis, rib fractures)

Bladder surgery Abdominal &/or thoracic surgery


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Pediatric Regional Anesthesia:

Neuroaxial Techniques

Caudal anesthesia and analgesia

Single dose local anesthetic

Morphine

Clonidine

Continuous infusion

Spinal anesthesia


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Caudal AnesthesiaTechnique


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Caudal Anesthesia


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Caudal Anesthesia


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Caudal Anesthesia

Needle or Angiocath


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Caudal Anesthesia

Where can it go?


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Caudal in a

http://www.cvm.okstate.edu/~users/aerrane/mandsagr/www/vms5422/lect22.htm


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Single Dose:

Caudal Morphine 3040 mcg/kg

Provides analgesia for 12-24 hours

No respiratory depression in over 500 children

Nausea incidence similar to general anesthesia

Less labor intensive

Does not require special pain service

Side Effects

Nausea Itching

Propofol therapy single dose

Do not need to go to PICUAnesthesiology 81:A1348, 1994J Clin Anesth 7:640, 1995


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Local with Clonidine

Clonidine in adults as oral sedative or

adjunct to spinal or epidural

Enhances and increases the effect of

single shot bupivacaine caudal

Risk: sedation with > 1mcg/kg

At UTMB, we use for caudal alone for

premies and hernia repair



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Awake Caudals in Neonates



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Caudal/Epidural Anesthesia and Analgesia:

Continuous Infusion Technique and Dose

Caudal 16g angiocath with 19g epidural catheter

Thread up to thoracic level

Guard with clear steridrape

Epidural-lumbar Use LOR to saline and continuous pressure method

If thread up to thoracic level, need epidurogram

Initial Dose: 0.05 ml/seg/kg

Anesthesiology 69:265, 1988Anesthesiology 79:400, 1993


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Caudal/Epidural Anesthesia and Analgesia:

Continuous Infusion Rates and Types

Rates

1 yoa: 0.1-0.4 ml/kg/hr

*less than 0.5 mcg/kg/hr fentanyl to start Types

1 yoa: 0.1% bupivacaine + 3 mcg/ml fentanyl

Anesth Analg, 75:164, 1992


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Continuous Caudal/Epidural Infusion:

Side Effects and Treatment

*If infusion has fentanyl, then turn down infusion& may use naloxone

Itching Diphenhydramine

Nausea

Metoclopramide

Urinary Retention Straight Cath prn

Sedation Turn Down Infusion

RespiratoryDepression

avoid sedating drugs

10 mcg/kg

Naloxone*

Naloxone

Naloxone

Naloxone

0.5-2 mcg/kg


P di t i R i l A th i


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Pediatric Regional Anesthesia:

Goals to Understand

Identify differences between adults and

infants

When indicated and contraindicated

Techniques

Side Effects and Complications


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Spinal Anesthesia

RARELY done

Technique

IV access

1.5" 22g beveled needle

Dose

Tetracaine 1 mg/kg and "whiff" (0.02 ml)

epinephrine


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Spinal Anesthesia

Positioning



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S i l A h i


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Spinal Anesthesia

Injection



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Spinal Anesthesia

Complications No hypotension seen in children under 6 years of age

If blood encountered, difficult to identify CSF

Limitations Procedure Duration 45 minutes

Surgeon

Pearls Sugar Nipple

Do not flex head

Bovie Pad

S i l A th i


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Spinal Anesthesia

Bovie Pad Placement