Regional Anesthesia for the Lower Limbs Dr. Prakash Ambardekar SeniorAnaesthesiologist

1. Regional Anesthesia for the Lower Limbs Dr. Prakash Ambardekar SeniorAnaesthesiologist Dept of Anesthesia SL Raheja Hospital, Mumbai

2. Diabetes Mellitus is not a simple endocrine disorder 1] Cardio-vascular system - Angina pectoris, silent small to massive Myocardial Infarcts , varying degrees of cardiomyopathies, varying types of Conduction blocks etc may be accompanied with Hypertension 2] Reno-vascular system - Nephropathies leading to Chronic renal failure 3] Central nervous system –Secondary effects 4] Autonomic nervous system -Sympathetic & Parasympathetic systems causing Autonomic Imbalance 5]Immunological system – suppression, prone to infections Contd…

3. Diabetes Mellitus is not a simple endocrine disorder 6] Septicaemia - following infection affecting various systems 7] Fluid & Electrolyte status altered. 8] Pulmonary system – alters ventilation and perfusion 9] G. I. system – slows gastric emptying - aspiration 10] Skeleto-muscular system - fusion of upper cervical vertebrae with limited neck movement, if accompanied with obesity & short neck Thus, in Diabetes, the selection of Anesthesia becomes a tricky and highly skillful job.

4. Why regional anaesthesia ? 1] Ideal for day-care patients 2] Safety in high risk patients 3] No intra-op regurgitation & aspiration 4] No PONV 5] Minimal alteration in drug schedule -specially in diabetics

5. Why regional anaesthesia ? Continued…. 6] Minimal effects on vital parameters 7] Safer in emergency situations 8] Can be repeated frequently 9] Conscious & arousable patient at the end of the surgery 10] Reduction in morbidity & mortality

6. Why not other modes of Anesthesia ?? General Anesthesia: [besides usual precautions] a] Risk of Aspiration and PONV b] Difficult intubations c] Resistant hypotension which may last for longer time d] Management of ischaemic changes and arrhythmias e] Management of blood sugar

7. Why not other modes of Anesthesia ?? Spinal & Epidural Anesthesia a] Prevention and management of hypotension b] Cannot be repeated frequently [ except in continuous epidural analgesia ] especially for small but painful procedures.

8. Limitations 1] Surgical time limit is between 1-3 hrs. 2] Patient’s co-operation is must 3] Failure or partially acted block

9. Types of blocks 1] Sciatic & femoral nerve block 2] Sciatic nerve block in lower thigh 3] Leg block a] low b] mid c] high 4] Field Block (small infected cysts, abscess, carbuncles)

10. Pre-block preparation • Besides usual instructions…. • Application of elastocrepe bandage • 2-3 days prior to surgery • Advantages :- • limb becomes soft & supple • reduced oedema , improved limb circulation • pH of tissue fluid alters • Success rate improves

11. Pre-block preparation Counseling the patient regarding the procedure and the expectation from the patient (compliance and accurate replies regarding paresthesia)

12. Lower leg block or modified ankle block Deep peroneal nerve – can be blocked by injecting subcutaneously 3-5 mm along the lat border of the shin with 2 ml 2% xylocaine with 24 g 1.5 inch needle

13. Lower leg block or modified ankle block Post. Tibial nerve – Blocked by injecting 3-5 ml 2% xylocaine at the junction of proximal 1/3rd with distal 2/3rd of medial malleolus to calcaneum, where normally pulsations of post. Tibial artery is felt.

14. Lower leg block or modified ankle block Sural nerve Inject 2% xylocaine between the tendoachilles and the calcaneaum on the lateral aspect

15. Lower leg block or modified ankle block Ring block – 0.5 % xylocaine around the leg to block cutaneous nerves

16. Lower leg block or modified ankle block Calcaneal nerve block 2 Finger breadths proximal to the medial malleolus Inject along the direction of the nerve

17. Mid leg block Anterior Tibial nerve Inject 2- 4 ml 2% xylocaine subcutaneously 5-7 mm along the lateral border of the shin

18. Mid leg block Posterior Tibial Nerve Spinal needle no 23 G is inserted from the lateral side of the leg over the ant. border of fibula going medially downwards just to slip the interosseous border of tibia , advance 1-2 mm & deposit 8-10 ml 2% xylocaine

19. Mid leg block Sural nerve Inject 2 – 3 ml 2% xylocaine along a line extended proximally tangential to the lateral border of the tendo achilles

20. Mid leg block Ring block 0.5 % xylocaine around the leg to block cutaneous nerves

21. High leg block Anterior Tibial nerve Inject 3-4 ml 2% xylocaine 5-10 mm deep lateral to the upper end of shin

22. High leg block Posterior Tibial nerve 2-4cm below the neck of the fibula Lateral approach – Spinal needle no 23 G is passed from the lateral side of the leg over the ant. border of fibula going medially downwards just to slip the interosseous border of tibia , advance 1-2 mm & deposit 8-10 ml 2% xylocaine

23. High leg block Lateral Popliteal Nerve 2- 4 ml 2% xylocaine injected around the neck of fibula

24. High leg block Ring block 0.5 % xylocaine around the leg to block cutaneous nerves

25. High leg block An alternate technique - If patient has a pain-free leg, then one may give sciatic nerve block in the lower third of thigh alongwith lat. Popliteal nerve block and ring block.

26. Steps to success with local blocks Practice regularly Your patience The surgeons’ patience The patients’ patience! Patients’ comfort The surgeons comfort Your comfort AND SAFETY!!

27. In Diabetic Foot Blocks are the way to go!!