Pediatric Regional Anesthesia Caudal Anesthesia Amr

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Pediatric Regional AnesthesiaCaudal Anesthesia

• Amr Abouleish, MD, MBA
• University of Texas Medical Branch
• Galveston, Texas

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Pediatric Regional Anesthesia

• How do children differ from adults?
• Why do regional anesthesia and analgesia in
  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
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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 Tetracaine with epinephrine

minutes
Cote, A Practice of Anesthesia for Infants and
Children
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Total Body Water
of bodyweight
lt15 week fetus
4-6 months
Adult
Full Term
Clin Pharm, 14189, 1988
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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, 14189, 1988
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General Pharmacology Implications

• ? CSF Volume ? ? dose ? duration
• ? Total Body Water ? ? IV dose, ? ? toxicity
• ? Protein Binding ? ? drug available ? ?
  toxicity
• ? Clearance ? ? t1/2 ? ? toxicity

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Local Anesthetics

• BE CAREFUL with repeated dosing and infusions
• Neurologic symptoms gt cardiac symptoms
• May not be able to illicit early neurologic
  symptoms in small 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, 75164, 1992 Anesth Analg, 75284,
1992 Anesth Analg, 75287, 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, lt6 months of age ? consider apnea
  monitoring
• For CEI, lt12 months of age ? no fentanyl

Anesthesiology 661389, 1987
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Anatomy
Cote, A Practice of Anesthesia for Infants and
Children
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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 former
  premies
• 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 regional
  alone

Anesthesiology 101A1470, 2004
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Combined Regional and General Anesthesia

• Usually regional anesthesia for postoperative
  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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Contraindications to Regional Anesthesia in
Pediatrics

• Parental refusal
• Need for intact sensory system for postoperative
  evaluation
• Sepsis
• Bleeding disorder
• Vertebral malformation or previous surgery
• Allergy

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Pediatric Regional AnesthesiaNeuroaxial
Techniques

• Caudal anesthesia and analgesia
• Single dose local anesthetic
• Morphine
• Clonidine
• Continuous infusion
• Spinal anesthesia

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Caudal Anesthesia Technique
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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 AnesthesiaWhere 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 DoseLocal Anesthetic Volume

• Traditional
• 0.05 ml/seg/kg
• 0.5 ml/kg ? T10
• 1.0 ml/kg ? T6
• For longer duration or lower concentration
• 1.5 ml/kg ? T2

Anesthesiology 47527, 1977 Anesthesiology 7557,
1991
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Single DoseConcentration of Local Anesthetic

• Balance analgesia with risk of motor block
• 0.25 Bupivacaine (max 1 mg/kg)
• Excellent analgesia
• Risk of some motor block
• Shorter duration cases
• Recommend patients lt 18 months of age
• 0.175 Bupivacaine (max 1.5 mg/kg)
• Less motor block with good analgesia
• Higher levels
• Longer duration
• Mix 10 ml 7 ml 0.25 3 ml NS

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Single DoseCaudal Morphine

• 30 40 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 PICU

Anesthesiology 81A1348, 1994 J Clin Anesth
7640, 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 gt 1mcg/kg
• At UTMB, we use for caudal alone for premies and
  hernia repair

Anesthesiology 101A1470, 2004
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Awake Caudals in Neonates
Anesthesiology 101A1470, 2004
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Anesthesiology 101A1470, 2004
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Anesthesiology 101A1470, 2004
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Anesthesiology 101A1470, 2004
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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 69265, 1988 Anesthesiology
79400, 1993
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Caudal/Epidural Anesthesia and Analgesia
Continuous Infusion Rates and Types

• Rates
• lt1 yoa 0.1 to 0.2 ml/kg/hr
• gt1 yoa 0.1-0.4 ml/kg/hr
• less than 0.5 mcg/kg/hr fentanyl to start
• Types
• lt1 yoa 0.1 bupivacaine
• gt1 yoa 0.1 bupivacaine 3 mcg/ml fentanyl

Anesth Analg, 75164, 1992
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Continuous Caudal/Epidural Infusion Side
Effects and Treatment
Naloxone
Itching
Diphenhydramine
0.5-2 mcg/kg
Nausea
Metoclopramide
Naloxone
avoid sedating drugs
Naloxone
Urinary Retention
Straight Cath prn
Sedation
Turn Down Infusion
Respiratory Depression
Naloxone
10 mcg/kg
If infusion has fentanyl, then turn down
infusion may use naloxone
Cote, A Practice of Anesthesia for Infants and
Children
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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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Approximate Distance Skin to Subarachnoid Space
MILLIMETERS
Premie
Newborn
5 months
Cote, A Practice of Anesthesia for Infants and
Children
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Spinal AnesthesiaPositioning
Cote, A Practice of Anesthesia for Infants and
Children
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Spinal AnesthesiaCSF Returns
Cote, A Practice of Anesthesia for Infants and
Children
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Spinal AnesthesiaInjection
Cote, A Practice of Anesthesia for Infants and
Children
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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

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Spinal AnesthesiaBovie Pad Placement
Cote, A Practice of Anesthesia for Infants and
Children