1. REGIONAL ANAESTHESIA IN PAEDIATRICS Dr. P. NARASIMHA REDDY Dept. of ANAESTHESIOLOGY NARAYANA MEDICAL COLLEGE NELLORE

2. HISTORY INTRODUCTION ADVANTAGES OF REGIONAL ANAESTHESIA RISK-BENEFIT RATIO ESSENTIAL THINGS REQUIRED HOW CHILDREN DIFFER FROM ADULT REGIONAL ANAESTHESIA PROCEDURES SUMMARY

3. HISTORY

4. First introduced at the end of last century at almost the same time as GA In 1898 BIER in his original paper on spinal anaesthesia on eleven year old boy described clinical effects JUNKIN, 1933 and ROBSON, 1936 described spinal anaesthesia for thoracic surgery Epidural anaesthesia in children was described by SIEVERS in 1936 1959 RUSTON introduced continuous epidural catheter technique.

5. Local anaesthesia was invented by LADD by infiltration for abdominal procedures in neonates in 1930 Sedation guidelines are released by ASA in 1996 and by AAP in 1992 and in 1997 by emergency physicians. In 1986 Dr. ANAND published his remarkable paper on pain in children and opened the eyes of many physicians’. RA in children is currently undergoing a renaissance in anaesthesia practice. RA with GA fulfills the characters of an ideal anaesthetic. RA is also becoming the main stay of post operative pain relief in children.

6. INTRODUCTION

7. Rarely done procedure French study – RA in paediatrics-12%, infants-1%, neonates and prematures-very rare

8. ADVANTAGES

9. Modification of stress response and improved out come. IVRA in emergency department for surgeries on extremities with full stomach Epidural with catheter is very useful in ortho surgeries and post operative pain relief Caudal block as anaesthetic, analgesic for post operative and also after bone marrow harvesting. Effective for controlling pain in ICUs where Narcotics are dangerous or inadequate leading to undesirable effects. Decreases the GA drugs Optimal post operative analgesia

10. RISK – BENEFIT RATIO

11. Warning signals are missing such as pain in case of intra neural or CNS Symptoms in case of intra vascular injection. It is an accepted procedure provided the clinician performs the technique care fully and skillfully DALENS 1999 quoted that “It would be considered malpractice to perform RA in children who are not fully anaesthetized”. De Negri 2002 said “Any performance of a block in a agitated moving child is not only unethical but could be dangerous when needle approaches the delicate nerve structures”.

12. ESSENTIAL THINGS REQUIRED

13. Skill in performing RA in adults for long time. Supportive surgical nursing facilities. Assistance in OR Proper equipment PACU and DSU Policies and procedures

14. HOW CHILDREN DIFFER FROM ADULT

15. Psychological and parents psychology Physiological Pharmacological Anatomical

16. PSYCHOLOGICAL: More apprehensive Separation phobia Universal needle phobia Pain and disfigurement in older children

17. PSYCHOLOGICAL: Parents and grand parents: Loss of control over the situation Dependency behavior Financial constraints Concern about the child’s problem and outcome

18. PHYSIOLOGICAL Post OP APNOEA is common in premature infants. Immature CNS Immature BBB Immature Sympathetic system Nerve fibreare thin, less myelinated, less nodes of Ranvier

19. PHARMACOLOGICAL: Volume distribution is more CSF volume high Total body water high Protein binding less Metabolism of drugs- Less than six months metabolism is less More than six months metabolism is active.

20. Rate of absorption of local Anaesthetic AIRWAY > INTERCOSTEL > CAUDAL > EPIDURAL >BRACHIAL > DISTALPERIPHERAL> SUBCUTAENIOUS DOSAGE OF Drugs: 0.25 % BUPIVICAINE 0.5 to 1ml per kg caudal

21. CSF Volume

22. Duration of action of LA

23. Total body water

24. Protein binding It is low at birth Albumin and alpha acid glycol protein less Comes to adult level at one year Clearance – Liver: phase 1 and phase 2 reactions decreased Kidney: GFR 30 % of adults Adult level by 3-5 years of age.

25. Morphine t 1/2 life is twice of adults IV < 6/12 Apnoea, Cei < 12/12 no fentanyl Be careful with repeated dosing and infusions Neurological symptoms > cardiac symptoms first symptom may be grand mal epilepsy

26. Anatomical:

27. Anatomical: Spinal cord is at lower level ( L3-L4) Laminae are not well developed CSF volume is high, turnover is high, shorter duration of LAs action No hypotension up to 6-8 yrs as sympathetic system is not well developed Epidural fat is like gel Ligaments are not well developed

28. REGIONAL ANAESTHESIA PROCEDURES

31. COMBINED RA + GA : Usually RA for anaesthesia and also for post operative pain relief Single caudal Continuous epidural / caudal Peripheral nerve blocks Field blocks Local infiltration.

32. Indications: All blocks which are possible in adults can be done. PNS can be used; ultra sounding also can be done. MH Avoiding need of OPIOIDS Better analgesia Epidural infusions Pulmonary diseases, fracture ribs Bladder surgery Abdominal and thoracic surgeries

33. Contra-indications: Parent refusal Sensory nervous system diseases Serious sepsis Bleeding disorders Vertebral malformations Previous surgery on spines Allergy

34. Caudal anaesthesia and analgesia Single Dose Continuous Infusions Adjuvants Spinal anesthesia

35. Caudal Anesthesia – Technique

40. Sacral ligaments

41. Dural sheath

42. Sacral marrow

43. Intra vascular

45. LA volumes: Traditional 0.05ml/seg/kg 0.5 ml/kg upto T-10 segments 0.25% Bupi 1 ml/kg upto T-6 segments For longer duration Lower concentrations with higher dosage – 1.5ml/kg upto T-2 segments

46. Concentration of local anaesthetics: Balance analgesia with risk of motor block, 0.25% Bupivacaine, maximum dose of 1mg/kg gives excellent analgesia, less motor blockade and shorter duration of action. 0.175% Bupivacaine, 1.5mg/kg causes less motor blocked, good analgesia with higher level and longer duration of action (10ml = 7 ml of 0.25 + 3 ml of NS)

47. Caudal morphine: 30-40 mcg provides analgesia for 12 to 24 hours no respiratory depression. Nausea present less labor intensive. Does not require special pain clinics. Side effects: Nausea, itching Clonidine: Increases the effects of Bupi. Risk of sedation if given more than 1 mcg/kg.

49. Continous infusions: Caudal 16 G angio-cath with 19 G epidural catheter can be threaded up to thoracic level and covered with sterile drape. Volume of drug: Less than 1 yr.: 0.1-0.2 ml/kg/hr More than 1 yr. 0.1-0.4 ml/kg/hr + Fentanyl: < 0.5 mcg/kg/hr Concentration of drug: Less than 1 yr.: 0.1% Bupivacaine More than 1 yr.: 0.1% Bupivacaine + Fentanyl

51. Epidural anaesthesia: Technically similar to adults except for Depth of epidural space is less Ligaments are thinner and difficult to feel the resistance Midline approach is preferred as laminae are not well developed Epidural fat is like gel and catheters can be passed very easily

53. Spinal anaesthesia: Technically similar to adults. Not very commonly done procedure, must have IV access, 1.5 inch 25 G beveled needle. Dose: 0.3-0.6 mg/kg of 0.5 % Bupivacaine heavy. Higher the age, lower the dose and vice versa

54. Distance from skin to Subarachnoid space

55. Spinal cord is at lower level ( L3-L4) Laminae are not well developed CSF volume is high, turnover is high, shorter duration of LAs action No hypotension up to 6-8 yrs as sympathetic system is not well developed Do not flex the head 25-30 G needle Lateral or sitting position

56. Combined spinal epidural (CSE): This overcomes shorter duration of action. Major procedures can done and post-operative analgesia well maintained.

57. PERIPHERAL BLOCKS

58. Penile block (Dalen’s sub pubic block):

59. Simple subcutaneous ring block at the root of the penis is sufficient but duration is only for 2-4 hrs.

60. Abdominal wall blocks: Ilio-inguinal and ilio-hypogastric block: Popularized by Shandling and Steward. Indications are: Herniotomy Orchidoplexy and Post-operative pain relief

62. Rectus sheath block First described in 1899, better done with ultra sound guidance This block is used for umbilical hernia repair or umbilical incision for lap procedures. Blocking nerves in the posterior part of the sheath deep to rectus muscle. Anterior an posterior blocks are available. A need is inserted lateral to umbilicus and advanced through the fascia which can be detected by loss of resistance. LA is injected bilaterally, 0.2 to 0.3 ml/kg, 0.25 % Bupivacaine. At least 6 minutes needed to get anaesthesia.

63. Transverse abdominal plane block (TAP) Blind injection at the triangle of DE PETIT. Now ultrasound guided injections are done between transverse and internal oblique muscles. This gives good post operative analgesia after appendectomy.

65. UPPER LIMB BLOCKS

66. Brachial plexus block: It can be sole anaesthetic or as an adjuvant to GA or for post OP analgesia or for sympathetic blocks. It should not be used for trivial reasons. Age is not a contra-indication for this block. Must be associated with GA. PNS or USG can be used to locate the nerves.

67. Inter scalene block:

68. Supra clavicular block:

69. Axillary block:

70. Para Scalene approach (DALENES): Patient supine with a role under the shoulder, arm by the side and head turned to opposite side. The injection site is the junction of upper ⅔ with lower ⅓ of the line joining the mid point of the clavicle and transverse process of sixth vertebra. Less complication.

71. LOWER LIMB BLOCKS

72. Femoral nerve block:

73. LATERAL CUTANEOUS NERVE OF THIGH (LCNT) BLOCK:

74. Sciatic nerve block (L4 – S2):

75. COMPLICATIONS

76. Complications due to the needle: Wrong needle Imprudently inserted Symptoms can be delayed by several hours Spinal haematoma

77. Complications related to technique: Location of nerve and space – electrical burns LOR syringe Saline Air Accidental PDPH

78. Complications due to catheters: Misplacement Kinking Knotting Migration Delayed lumbar stenosis Shearing Bacterial contamination

79. Complications due to LA solutions: Local toxicity : Injection of wrong solutions Continuous infusions Preservatives and additives High concentrations

80. Systemic toxicity CNS toxicity Cardiac Methhaemoglobinemias Most LAs are anticonvulsants (1-5 mcg) High concentartionsconvulsant and respiratory arrest Drug interactions – digoxin , bilirubin, cimetidine and propronolol.

81. Methaemoglobinemia : Can occur after several hours With prilocaine and benzocaine and rarely lidocaine. Predisposing factors G6p deficiency Aniline dyes Oxidants Treatement – injmethyline blue 1-5 mg/kg

82. Complications due to adjuvants: Preservatives like metabisulfate, antioxidants can produce severe toxicity Narcotics can produce respiratory depression , pruritis , bladder distension.

83. Complications resulting from inadequate management: Bacterial contamination Unsafe technique of injection – high pressure epidural injection Injection in the wrong space

84. Complications wrongly attributed to regional blocks: Hypotension , blood loss, position, surgical manipulation Sickle cell disease Sudden infant death syndrome

85. CONCLUSIONS All blocks can be given like adults Differences from adult in various body systems must be known PNS or ultrasound guidance is advisable Blocks are given under GA, be careful about injuring the nerves and intravascular injections Continuous catheters with infusion can be used Correct dose and correct drug must be selected Be careful with narcotics in pre-mature children Be careful with adjuvants

86. Conclusions………. Emergency equitment for CPR, if required should be available Necessary monitoring systems should be present IV access Starvation guideline Proper equipment and needles Adequate exposure to regional anaesthesia in adults PACU and DSU facilities Recovery room facilities Discharge guidelines

87. THANK YOU