LATERAL APPROACH VERSUS POSTERIOR APPROACH FOR , SCIATIC NERVE BLOCK IN THE POPLITEAL FOSSA. A COMPARATIVE STUDY

Abstract

Sciatic nerve block in the popliteal fossa is performed for procedures of the foot and ankle where more proximal blocks (hip) is not feasible, or when the ankle blocks. are contraindicated because of the presence of swelling or infection in the ankle.

In combination with saphenous nerve block, popliteal nerve provides complete anaesthesia to the foot and ankle.This form of anaesthesia avoids the sympathectomy associated with centroneuroaxis blocks, and therefore, its use may be advantageous when any shift in the haemodynamics could be deleterious, •such as in patients with significant aortic stenosis.

The main disadvantage of the classical posterior approach to the sciatic nerve block in the popliteal fossa is the need to place the patient in the prone position. This position may preclude the use of the PB m patients who could benefit the most from this technique (i.e. those m advanced stages of pregnancy, those wi_!h morbid obesity, spine and haemodynamic instability, mechanical ventilation).