1. Peri-operative pain
You think I don't
management feel pain? Well,
this isn't my "happy
in children
to see you" face!!!!
Jerrold Lerman BASc, MD, FRCPC, FANZCA
Clinical Professor of Anesthesiology
Women’s & Children’s Hospital of Buffalo, SUNY,
Strong Memorial Hospital, University of Rochester,
New York
Pain management
Albert Schweitzer wrote:
“We all must die. But that I can save him from
days of torture, that is what I feel as my great and
ever new privilege. Pain is a more terrible lord of
mankind than even death itself.”
On the edge of the Primeval Forest,
New York, Macmillan, 1931, p 62
Pain Framework Pain management
Parents’ management of children’s
pain following ‘minor’ surgery
“Even when parents recognise that their children
are in pain, most give inadequate doses of
medication to control the pain.”
Finley GA, et al
Pain 64:83, 1996
1

2. Pain management Individualize the care
Multidisciplinary team approach:
• MD (anesthesiology, surgery)
• RN (pain team, PACU, ICU, ward)
• Pharmacist
• Resident-trainees
• Pediatrician
• ….and the parents/caregiver
Pain Management Pain management
Preoperative strategies:
When: • Preop assessment:
• All perioperative pain • Patient history, medications, preferences
• For what duration postop? • Pre-existing diseases/disorders
• Hours ⇒ days? • Parents/caregiver knows the child best
• Where? • Pain threshold? MMC have sensory level
• Ward • Modalities available…
• PICU
• Education
• NICU
• Surgical requirements
PCA Dosing Regimen PCA Dosing Regimen
PCA dosing: Optimal regimen:
• For morphine: • Background infusion permits 50% of the
• PCA bolus: 10-30 µg/kg bolus dose compared with no bckgrd,
• Continuous rate: 10-40 µg/kg same end-points Yildiz K, et al
• Lockout interval: 6-10 minutes Ped Anesth 2003:13;427
• 4 hour limit: 0.25-0.40 mg/kg
• Alternatives include dilaudid (hydromorphone)
• For weaning…
(and demerol) • First ensure tolerating po fluids
• d/c the background infusion
• Determine total daily morphine consumption
as oral analgesic dose
2

3. Can Surgeons be trained to run PCA? The safety and efficacy of parent-/nurse-
controlled analgesia in patients less than
six years of age
Monitto CL, et al
Anesth Analg 91:573, 2000
• Retrospective 1 year review of 212 children,
240 PNCA uses
• 2.3 ± 1.7 yr
• Median 4 days used
• > 80% had OPS ≤ 3/10
PNCA Outcomes Non-opioid Analgesics
Parent/nurse controlled analgesia (PNCA): Analgesics:
• Complications • Acetaminophen
• 8% incidence of pruritus • Codeine, Tramadol
• 15% vomiting on POD 1 • NSAIDs:
• 1.7% PNCA-related apnea or desaturation • Ketorolac, Ibuprofen, Diclofenac
• Improved with naloxone • COX-2: no longer used
• ASA: no longer used
Monitto CL, et al
Anesth Analg 2000:91;573
Non-opioid iv analgesics Non-opioid Analgesics
Propacetamol: Codeine:
• 30 mg/kg Pro (15 mg/kg para) q6h iv • Liquid: acetam + codeine 120/12 mg - 5 ml
• Clearance is reduced in 27 wk PCA, • Tablets:
matures to 84% by 1 year • Tylenol #2: Acetam 325 mg + 15 mg codeine
• Effective analgesic blood levels of 10 • Tylenol #3: Acetam 325 mg + 30 mg codeine
mg/L para achieved in 2-15 year olds • Tylenol #4: Acetam 325 mg + 60 mg codeine
• Effective analgesic for mild/mod. pain
• Oxycodone: 0.1-0.15 mg/kg q4-6h
Anderson BJ, et al
Ped Anesth 2005:15;282
3

4. Non-opioid Analgesics Non-opioid iv analgesics
Codeine: Ketorolac:
• Common and safe • Dosing: 0.5-1 mg/kg q6h
• Effective analgesic by metabolism to • Advantages:
morphine in vivo • Equivalent analgesia
• Polymorphisms in > 10% of children! • Opioid sparing, ⇓ PONV, bladder spasm
• Deficient in CYP 450 2D6 for conversion
• ⇓ respiratory depression
• Wild polymorphism: ultra-rapid metabolizer
• Ciszkowski, et al. NEJM 2009:361;827. • Disadvantages;
• Side effects: respiratory depression, • Risk of bleeding?, bone-healing,
constipation in CP children bronchospasm, acute renal insufficiency
Who volunteers for a regional block?
Non-opioid iv analgesics
Tramadol:
• Synthetic codeine analogue, uncontrolled
• Mechanism of action is µ-receptor and inhibition of
neurotransmitter reuptake
• Dosing: 1-2 mg/kg iv
• Advantages: lack of sedation, min. respiratory
depression
• Disadvantage: PONV…5HT3 mediated (partic. after
oral dose) (5HT3 anti-emetics reduce analgesic
efficacy…at spinal receptors?)
Are Cont. Epidurals Dead? Are Cont Epidurals Dead?
The facts: Problems with epidurals:
• 17-23% of epidurals terminated prematurely • Catheter tip has to be in epidural space
• 67% incidence of side Fx/complications • Catheter tip needs to be near surgery
• 6% had back pain post (in 1 study)
• Block may be unilateral or patchy
• Open tip or multi-orificed
• Is there evidence that continuous epidurals • Change LA/add adjuvants if poorly functioning
provide BETTER outcomes than other forms of
analgesia? • Side effects:
• PONV, motor blockade, pruritus, urinary retention, poor success
• Is there evidence of superior alternatives? rate, add clonidine but creates problems, epidural
hematoma/abscess, respiratory distress, air embolism, PDPH,
nerve trauma
Chalkiadis G, Chalkiadis G,
Paed Anaesth 2003:13;91 Paed Anaesth 13:91, 2003
4

5. Epidural Analgesia Regional Anaesthesia
Caveats/side effects:
Complication rate in 24,000 blocks:
• Avoid neuroaxial blocks with ⇑ ICP? • caudal 0.7/1000
• Infection, headache • sacral caudal 6.8/1000
• Toxic responses: • lumbar epidural 3.7/1000
• L.A. lower seizure thresholds by 50%
• thoracic epidural 0/1000
• Repeat pain evaluations
• spinal 2/1000
• Pressure sores
• Compartment syndrome • peripheral blocks 0/1000
Giaufre, et al.
Anesth Analg 83:904, 1996
Regional Anaesthesia Caudal Blocks
Incidence of critical events is low, but the
complications may be devastating:
• anaesthetic overdose
• respiratory depression
• neuropraxia
• paralysis
• infection
• cardiac arrest and death • Dermal puncture with 18 ga needle • Passive backflow
• Use BD angiocath® (stiff catheter) • ECG is OBSERVED
• Advance catheter 2 mm • Whole volume is a test dose
Ambulatory Surgery Single Shot Caudal Block
What volume should we use?
Caudal/epidural blocks:
• 54 children, 1-6 years, inguinal hernia
• optimal concentration for single-shot is:
• 0.175% bupivacaine with epi
BUPIVACAINE 0.175%, 1.0 ml/kg (max. 20 ml)
• 0.25% bupi x 7 ml plus NaCl x 3 ml = 10 ml (or 20 ml)
• Bupi volume: 0.7, 1.0 and 1.3 ml/kg
• maximum analgesia, minimal motor block, no • NO difference in time to first analgesia,
urinary retention ambulation or discharge
Gunter et al,
Anesthesiology 75:57, 1991 Schrock CR, et al
Paed Anaesth 2003:13;403
5

6. Life-threatening Arrhythmias Intralipid for LA Toxicity
Intravascular and intraosseous injections
Peaked T waves ± ST segment elevation
Intralipid 1 ml/kg, repeat x 3 www.lipidrescue.org
Badgwell JM, et al May 7, 2007
Epidural Catheters Continuous Epidurals
Successful placement of tip for remote To prevent excessive bupivacaine
surgery: concentrations in neuroaxial infusions:
• Preferrable to use a stiff/larger catheter • same loading dose as ambulatory
• 17 or 19 ga rather than 22 ga • begin caudal/epidural infusions immediately
• Use caudal rather than epidural route after the loading dose at:
• Place catheter at level block required • neonates: 0.2 -0.25 mg/kg/h 0.2 ml/kg/h of 0.1-0.125%
bupivacaine
• Tsui technique • infants: 0.2-0.4 mg/kg/h 0.3 ml/kg/h of 0.1-0.125%
• Epidurogram • children: 0.4-0.5 mg/kg/h bupivacaine
• Use morphine instead of more soluble agents
Berde C.
Anesth Analg 1996:83;897
Epidural Bupivacaine in Neonates Caudal Catheters
Colonization Rate
30 (10/34)
Bupivacaine 0.2 mg/kg/h
20
(%)
(36/343)
10 (3/32)
0
Untunneled Tunneled Lumbar
Larsson BA, et al Caudal Bubeck J, et al
Epidural Anesth Analg 99:689;2004
Anesth Analg 1997:84;501
6

7. Caudal Catheter Tunneling PCEA in Children
Two studies:
• 128 children, ≥ 5 years: ortho, pectus, renal,
laparotomy, thoracotomy, etc
• Bupi 0.1% with Fentanyl 5 µg/ml,
• Continuous < 0.2 ml/kg/h
• Demand 1-3 ml
• Lockout 15-30 min
• Max: < 0.4 mg/kg/h
Bubeck, J, et al Birmingham et al
Anesth Analg 2004:99;689 Anesth Analg 2003:96;686
PCEA in Children Stereoisomers
PCEA vs CEA: Racemic mixture:
• 48 children, 7-12 years, postop pain, lumbar epidural
• equal concentrations of each stereoisomer
• Ropi 0.2% @ 10 ml
• PCEA: Chiral Compound:
• Ropi 0.2% @ 2 ml boluses • “handedness” non-superimposable, mirror images
• Lockout 10 min
• Infusion 1.6 ml/h Stereoisomers:
• Max 13.6 ml/h
• same compounds but different 3-D configuration
• CEA:
• Ropi 0.2% @ 0.4 mg/kg/h
• eutomer is the more potent isomer,
• distomer less potent;
• Results: PCEA 0.2 ± 0.08 mg/kg/h • eudismic ratio is the ratio of their potencies
(P < 0.001)
CEA 0.4 ± 0.08 mg/kg/h
Antok, et al
Anesth Analg 2003:97;1608
Relative Cardiac Severity
Relative Cardiac Severity
15 Caudal Solution Additives
Table 1 Drugs added to local anaesthetic solutions in paediatric caudal anaesthesia, frequency of usage and doses used
95% confidence
Drug added to local Frequency of use by intervals for
10 anaesthetic 210 respondents (%) percentage Dose range (mode)
Epinephrine 24 (11) 7.5, 16.5 1: 200,000
-1 -1
Fentanyl 44 (21) 15.7, 27.1 0.5–4.0 µg ml (2.0 µg ml )
-1 -1
Diamorphine 27 (13) 8.7, 18.2 20–50 µg ml (20 µg ml )
-1 -1
Clonidine 55 (26) 20.4, 32.7 0.5–2.5 µg ml (2.0 µg ml )
-1 -1
Ketamine 67 (32) 25.7, 38.7 0.25–1.00 mg ml (0.50 mg ml )
Bicarbonate 7 (3) 1.4, 6.8 Not specified
-1 -1
5 Morphine 4 (2) 0.5, 4.8 50–100 µg ml (50 µg ml )
-1
Midazolam 1 (0.5) 0, 2.6 0.5 µg ml
Br. J. Anaesth. 2002; 89:707-710
Journal Content Copyright © 1991-Present, ASA, IARS, BJA, CAS. All Rights Reserved. Reproduction of said
Sanders
JC
material, without prior permission from the Proprietor holding the copyright to the material, is illegal.
BJA 2002:89;707
0
Bupivacaine Ropivacaine Lidocaine
Reiz & Nath
Reiz & Nath
Acta Anaesth Scand 33:93-8, 1989
Acta Anaesth Scand 1989:33;93-8
7

8. Epidural Fentanyl Epidural Morphine
Pharmacology:
Is there a role in children? • single epidural doses of 33 - 100 µg/kg last 10-13 h
• Limited evidence in children (and 3-5 µg/kg/h titrated to effect…analgesia, sedation)
• At Fentanyl 1 µg/ml alone at 0.3 ml/kg/h confers • incidence of PONV, pruritus ranges from 20-40%
> 90% analgesia
• urinary retention has not been evaluated
• Strong evidence of side effects, particularly with
• 9% of 136 children with duramorph required
escalating doses
naloxone:
• Pruritus
• Urinary retention • 10 of the 11 children were < 1 yr
• 6 of 10 had also received parenteral opioids
Lerman, et al
• Postoperative monitoring!!!!!!!
Anesthesiology 2003:99;1166
Nonopioid Additives Clonidine for Caudal Analgesia
Systematic Review:
• RCTs, < 18 years, up to 2002
• 17 of 107 studies were accepted
• 12 clonidine, 4 ketamine, 2 both, 2 midazolam and 1
adrenaline
• Clonidine (n = 12)
• Dose range: 1-5 µg/kg
• Dose-dependent increase in duration of analgesia
• Dose-dependent increase in degree of sedation
• No respiratory depression
Ansermino M, et al Ansermino M, et al
Paed Anaesth 2003:13;561 Paed Anaesth 2003:13;561
Clonidine Non-opioid Additives
Systematic Review:
Economics: • Ketamine (n=5):
• Roxane Pharmaceuticals -- Duraclon • 0.25-0.5 mg/kg increased duration of analgesia
• Avg increase in analgesia: 7h
• Single dose, no preservatives
• No increase in sedation or emesis
• 100 µg/ml x 10 ml -- $23.62 • 1 mg/kg ketamine, sole agent, behavioral changes
• At 1 µg/kg, the cost of clonidine is 2.36 CENTS/kg! • Midazolam (n=2):
• Entire ampoule use…avg $1.00/kg • 50 µg/kg adjunct to bupivacaine
• Increased duration of analgesia 3.5h
• NOT indicated for acute pain…only chronic • No sedation evident
• Toxicology shows no evidence of neurotoxicity • Adrenaline (n=1):
• Effect depends on site of surgery and age of child
• Useful to detect intravascular injection
Ansermino M, et al
Paed Anaesth 2003:13;561
8

9. S(+)-Ketamine Caudal Neostigmine
Its role in caudal analgesia? POV
• Preservative free
25%
• Twice the analgesic potency of the racemate
• Fewer psychomotor disturbances
• Less salivation
• More rapid recovery
• 30 children, 0.125% bupi ± 0.5 mg/kg S-ketamine
10%
30%
Weber F, Wulf H, Abdulatif et al
Paed Anaesth 2003:13;244 Anesth & Analg 2002:95;1215
Nonopioid Additives Regional Anaesthesia
Cautionary notes:
In children:
• Ketamine, midazolam and clonidine are NOT
licensed for acute epidural pain management • Safe techniques
• Clonidine is marketed for epidural • Levo enantiomers preferrable
(preservative-free) use…chronic pain • Levobupivacaine, ropivacaine
• Clonidine shows no evidence of neurotoxicity • Adjunct agents:
• Inadvertent intrathecal injection of ketamine or • Epinephrine
midazolam may lead to neurologic event • Clonidine
• ?Fentanyl
• Lidocaine 5% was safe -- then 5 cases of cauda • Morphine
equina syndrome (Acta Scand Anaesth 1999) • ??Ketamine, neostigmine, midazolam
Nerve Blocks Pain management
Monitoring epidurals on the ward:
• 53 peds institutions responded
• 50% were < 200 beds, 50% > 200 beds
• 92% routinely use continuous monitors
• 37.5% use oximetry only
• 30% use oximetry and apnea
• 7.5% use apnea only
• 7.5% use NO MONITORS
Brislin RP, Rose JB. Brenn et al.
Anesth Cl N Am 2005:23;789 Anesthesiology 1995:83:432
9

10. On Q -- L.A. for surgeons Nerve blocks or SubQ?
Two studies, 13 years apart:
• Casey WF, et al. Anesthesiology 1990:72;637. A
comparison of bupivacaine instillation versus II/IH
nerve block for postoperative analgesia following
inguinal herniorrhaphy in children.
• Machotta A, et al. Paed Anaesth 2003:13;397.
Qualities: Comparison between instillation of bupivacaine
• Easy, safe and portable versus caudal analgesia for postoperative analgesia
• Analgesia for DAYS! following inguinal herniotomy in children.
• Direct local effect
• Few side effects: systemic?
• Dose limited No Difference!
Okay Doc, now give
me your best pain control
or I’ll let my parents
loose on you!
10