Regional Anaesthesia in Paediatric Cardiac Surgery

1
Regional Anaesthesia in Paediatric Cardiac Surgery

• Professor Andrew Wolf
• Consultant in Paediatric Anaesthesia and
  Intensive Care, Bristol UK

2
Why Regional For Paediatric Cardiac

• Reduced Neuroendocrine disturbance
• Improved Pulmonary Function
• Increased cardiovascular stability
• Improved Analgesia
• DVT prophylaxis
• Early return of Bowel function

Hammer GB, Wolf AR Techniques in Regional
Anesthesia and Pain management 2008 12 64 - 71
3
Regional Anaesthesia

• Local Anesthesia
• Loss of pain.sensation
• Motor block
• Sympathetic block vasodilation
• Afferent block stress responses damped
• Analgesia without systemic CNS depression

4
Regional Anaesthesia

• Spinal CNS Opioid
• Long lasting analgesia (limited effect on stress
  response
• Morphine 24hrs (non segmental)
• Fraction of systemic opioid dose
• Sedation
• Vomiting, pruritus
• (Sudden late ventilatory depression)

5
Caudal Anesthesia

• A relatively benign Block
• Rosen and Rosen Anesthesiology 1989 70 418 421
• 75mcg/kg morphine at the end of the procedure
• 6hrs pain relief ( 2-12 hrs)
• Reduced pain scores
• 50 of postoperative analgesia

6
Spinal Anaesthesia/Cardiac Surgery

• Mathews Lancet 19802 1980
• adult study in cardiac (40 patients)
• 1.5 4mg morphine intrathecally
• 24 hours analgesia
• Jones BJA 198456 137- 40
• -15 hours analgesia after single shot
• Finkel Anesthesiology 1997 87 1052
• 5,7,10mcg/kg morphine
• extubated at the end, no ventilatory depression

7
Peterson KL, DeCampli WM, Pike NA, Robbins RC,
Reitz BA A report of two hundred twenty cases
of regional anesthesia in pediatric cardiac
surgery Anesth Analg 2000 90 1014-9 Hammer
GB, Ngo K, Macario A A retrospective
examination of regional plus general anesthesia
in children undergoing open heart surgery.
Anesth Analg 2000 90 1020-4 Steven JM, McGowan
FX, Jr. Neuraxial blockade for pediatric cardiac
surgery lessons yet to be learned. Anesth Analg
2000 90 1011-3
8
220 cases Retrospective only 89 extubated in the
operating room 4.1 reintubation No Major
Complications
Anesth Analg 2000 90 1014-9
9
New procedures in children

• Very low risk but low gain
• Very low risk High gain
• Risk but low gain
• Risk but potential high gain..
• ..needs careful prospective evaluation

10
Why use Regional Techniques for Open heart
surgery?

• Fetal bypass and total spinal.
• Fenton KN. J Thoracic and cardiovascular surgery
  1994 107 1416 1422
• Thoracic epidural anaesthesia (TEA) can
• reduce infarct size after coronary occlusion
• Davis RF Anesthesia and Analgesia 1986 65 711
  717
• TEA reduces postoperative ischaemia
• Staats PS. Cardiothoracic and Vascular Anesthesia
  1997 11 105 108
• Reduced troponinT release after surgery
• Loik HM. Anesthesia and Analgesia 1999 88 701
  709.

11
Effects of Stress Responses 1

• Hyperdynamic circulation
• Cardiovascular strain
• Positive fluid balance
• Vascular permeability
• Hypercoagulability

12
Effects of stress Response 2

• Hyperglycaemia
• Nitrogen loss
• Increased oxygen requirements
• Loss of body weight
• Immune function

13
High Dose Opioids

• Positive
• Stress reduction
• Pain elimination
• Cardiovascular stability

• Negative
• Ventilatory depression
• Immunomodulation
• Prolonged PICU stay
• Tolerance/withdrawal

14
(No Transcript)
15
Acute Tolerance with Opioids

• Adult study 50 patients
• 0.5 desflurane remifentanil titrated
• 0.1mcg/kg/min remi desflurane titrated
• 0.15mg/kg morphine loading
• Pain scores, morphine requirement

Guignard B et al Anesthesiology 2000 93 409
16
Guignard B et al Anesthesiology 2000 93 409
17
The Fast Track Cardiac Experience

• Based on experiences in the developing world
• Cost Driven Practice in USA
• Loma Linda (Ann Thoracic Surg 2000 69 865
  871)
• Charlottesville (Crit Care Med 2002 30 787
  791)

18
The Loma Linda Experience

• Low Dose opioid in most cases
• Isoflurane /Desflurane
• 10-15mcg/kg fentanyl during surgery
• Postop strategy
• Bypass management
• 87 extubated on table
• 93 within 4 hours

But there are going to be significant
neuroendocrine responses
19
What about regional analgesia?
20
Spinal vs Epidural Techniques
21
(mmol/L)
Morgan N, Wolf AR Paediatric Anaesthesia
19988305-313
22
Wolf AR et al Paediatric Anaesthesia 1998 84
305 - 313
23
Morgan N, Wolf AR Paediatric Anaesthesia
19988305-313
24
Can This Be Applied to Cardiac Surgery? And Does
this Have Benefit?
25
High Spinal Anaesthesia for Cardiac Surgery in
Adults

• Randomised db controlled trial
• Reduced atrial ß-receptor dysfunction
• Higher Cardiac index postbypass
• Lower Pulmonary vascular resistance
• Lower intrinsic plasma catecholamines

Lee TW et al Anesthesiology 2003 98 499-510
26
(No Transcript)
27
TOE assessed LV function
Lee TW Anesthesiology 2003 98 499
28
Lee TW Anesthesiology 2003 98 499 - 510
29
(No Transcript)
30
Regional Anaesthesia in Paediatric Cardiac Surgery

• Risks
• Extra procedure
• Haematoma
• (epidural 1in 150,000)
• (spinal 1in 220,000
• Abscess
• Blood pressure control
• Heart rate
• Late ventilatory depression

Tryba M Anesth Analg 1994 79 1165 - 1177
31
Spinal Anaesthesia for Paediatric Open heart
Surgery in Bristol
32
(No Transcript)
33
Why Spinal Catheters?

• Below spinal cord
• Smaller instruments/ needles
• Identifiable endpoint/ simplicity
• Potency
• Controllable
• Postoperative analgesia

34
(No Transcript)
35
(No Transcript)
36
(No Transcript)
37
(No Transcript)
38
Methods 1

• Randomised prospective controlled trial
• 60 patients (30 spinal/ 30 high dose opioid)
• neonates 24 months
• Stress and inflammatory responses

39
Spinal Anaesthesia Regimen

• Insert catheter at L3/4 or L4/5
• 20µg/kg preservative free morphine before surgery
• 0.5ml/kg of 0.25 bupivacaine before bypass
• 0.2ml/kg of 0.25 bupivacaine on rewarming
• Start bupivacaine/opioid infusion
• 0.1ml/kg/hr of 0.125 bupivacaine morphine
  (3µg/kg/hr)
• Run midazolam iv for sedation on PICU

40
Conventional Anaesthesia

• Sevoflurane/iv induction
• O2 /air/ isoflurane anaesthesia
• Pre-bypass fentanyl iv (25µg/kg/hr)
• Infused fentanyl on bypass (15µg/kg/hr)
• Midazolam/isoflurane during bypass
• Morphine midazolam in PICU

41
(No Transcript)
42
CORTISOL
Different to the Lee Study..
43
(No Transcript)
44
Interleukins
45

46
(No Transcript)
47
Results Spinal vs Opioid

• Reduced catecholamines
• Reduced NPY
• Reduced lactate
• Reduced variability IL-6 (lower)
• Insufficient power for outcome data

Humphreys N, Wolf AR Anesthesiology 2005103(6)
113
48
Results Spinal vs Opioid

• Improved gut function?
• Reduced renal failure?
• Increased benefit in neonates?
• Reduction in PICU/Ward stay X

Humphreys N, Wolf AR Anesthesiology 2005103(6)
113
49
What about the Haemodynamic effects?
50
Dohi Anesthesiol 1979 50 319
51
CPB and Spinal Anaesthesia

• Allows direct measurement of Cardiac Output/
  cardiac index
• Direct pressure measurement
• Calculated SVRI possible

Lovell AT, Al Sharma M, Wolf AR BJA 2003 90
821P
52
Mean Arterial Pressure
53
Cardiac Index
54
Systemic Vascular Resistance
55
SVRI ChangeInfants vs 1-5yr olds
Lovell AT, Al Sharma M, Wolf AR BJA 2003 90
821P
56
Spinals stress elimination
Organ function?
57
Fast Track Management

• Analgesia not a major problem
• Sedation is!
• ..But not immediately
• ..and not in infants lt6months
• PICU need to be ready

58
Infant/Neonatal technique

• Fentanyl 10 -25ug/kg total case dose
• modulate volatile volatile on bypass
• Spinal Morphine 15mcg/kg after induction
• Local (0.25 bupivacaine) on bypass
• (0.3ml/kg)
• clonidine/bupivacaine on rewarm
• continue on unit (24 hours)

59
Infant/Neonatal technique

• Post Surgery
• Infants older than 6 months clonidine loading
• Spinal infusion 0.125 with clonidine (20mls
  with 75mcg clonidine run at 0.1 0.2ml/hr
  0.3-0.75mcg/kg/hr)
• Supplemental Low dose Morphine infusion iv
• Regular paracetamol
• Extubate and titrate
• CSF leaks

60
Current Evaluation

• 22 cases in last 9 months
• VSD 9
• AVSD/ AV canal 2
• Fallots 4
• Fallots AVSD 2
• Glenn 1
• Switch 1
• TAPVD 1
• Unifocalisation 1

Weight 7.2 (SD 2.6)kg Age 8.5 (SD 4.5) months
61
T0
D1
D2
D7
62
Complications

• Reoperation for atrial bleed
• Pulmonary hypertension post spinal
• Unsettled overnight
• ECMO in Complex TAPVD