Rationale For Use of Lower Extremity Conduction Nerve Blocks

Selection of the analgesic modalities for postoperative analgesia

Although perception of pain is highly variable among patients, it is possible to estimate the intensity and duration of postoperative pain in most patients and elective surgery scenarios. There are three main commonly encountered scenarios in clinical practice: outpatient surgery, elective surgery on hospitalized patients and emergency procedures.

Outpatient surgery often requires "minimally" invasive anesthesia, i.e., anesthetic techniques with short-acting intravenous or inhalational anesthetics, which results in short-lived and substandard postoperative analgesia at home in a significant proportion of patients.[10-12] When applicable, a regional block with LA with or without the addition of an adjuvant (e.g., clonidine) is the most effec-tive choice. Both intraoperative and postoperative analgesia is ensured by the same technique, in most cases allowing for administration of light general anesthesia.

Hospitalized patients more commonly undergo more extensive surgical procedures that usually require long lasting techniques of analgesia. If the patients are only exposed to pain at rest, regio-nal anesthetic techniques and administration of parenteral opioids (PCA especially) are similarly effective (13,14). However, if pain at mobilization (especially following orthopedic procedures) or procedural pain (wound dressings, mobilization of drainages) is expected, analgesia achieved with regional blocks is far superior to that achieved with parenteral narcotics.

Emergency procedures: Patients requiring emergency procedures and/or those whose physical status is not stabilized require special attention. Whenever applicable, peripheral nerve blocks are preferred because they do not change the level of consciousness or affect the hemodynamic stabi-lity. However, precautions must be taken as there may be legal implications in case of neurological lesions that were not fully evaluated and/or documented, preferably in the presence of a witness and/or by a neurologist, before the performance of the nerve block procedure.

Abstract

Introduction

Rationale

Indications

Contra-indications

Equipment

Techniques

Summary

References