Regional Anesthesia Regional Anesthesia for the Lower Limbsfor the Lower Limbs

Dr. Prakash Ambardekar SeniorAnaesthesiologist Dept of Anesthesia SL Raheja Hospital, Mumbai

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…

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.

Why regional anaesthesia ?

1] Ideal for day-care patients2] Safety in high risk patients3] No intra-op regurgitation & aspiration4] No PONV5] Minimal alteration in drug schedule -specially in diabetics

Why regional anaesthesia ? Continued….

6] Minimal effects on vital parameters7] Safer in emergency situations8] Can be repeated frequently9] Conscious & arousable patient at the end of the surgery10] Reduction in morbidity & mortality

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

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.

Limitations

1] Surgical time limit is between1-3 hrs.

2] Patient’s co-operation is must3] Failure or partially acted block

Types of blocks

1] Sciatic & femoral nerve block2] Sciatic nerve block in lower thigh3] Leg block a] low b] mid c] high4] Field Block (small infected cysts, abscess,

carbuncles)

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

Pre-block preparation

Counseling the patient regarding the procedureand the expectation from the patient(compliance and accurate replies regarding paresthesia)

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

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.

Sural nerve

Inject 2% xylocaine between the tendoachilles and the calcaneaum on the lateral aspect

Lower leg block or modified ankle block

Ring block – 0.5 % xylocaine around the leg to block cutaneous nerves

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

Lower leg block or modified ankle block

Mid leg block

Anterior Tibial nerve

Inject 2- 4 ml 2% xylocaine subcutaneously 5-7 mm alongthe lateral border of the shin

Mid leg block

Posterior Tibial NerveSpinal 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

Mid leg block

Sural nerve

Inject 2 – 3 ml 2% xylocaine along a line extended proximallytangential to the lateral border of the tendo achilles

Ring block

0.5 % xylocaine around the leg to block cutaneous nerves

Mid leg block

High leg block

Anterior Tibial nerve Inject 3-4 ml 2% xylocaine 5-10 mm deep lateral to theupper end of shin

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

Lateral Popliteal Nerve

2- 4 ml 2% xylocaine injected around the neck of fibula

High leg block

Ring block

0.5 % xylocaine around the leg to block cutaneous nerves

High leg block

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.

 

High leg block

An alternate technique -

Practice regularlyYour patienceThe surgeons’ patienceThe patients’ patience!

Steps to success with local blocks

Patients’ comfortThe surgeons comfortYour comfortAND SAFETY!!

In Diabetic Foot

Blocks are the way to go!!