Outpatient lower extremity infusions.
The considerable development of ambulatory surgery has led to an increase in the number of lower extremity procedures performed in an outpatient setting. More recently, the availability of disposable pumps has allowed us to extend the indications of continuous nerve blocks for ambulatory post-operative pain management. Indications for lumbar plexus continuous blocks include anterior cruciate ligament (ACL) reconstruction and patella repairs as well as frozen knee, whereas continuous sciatic blocks are indicated for major foot and ankle surgery. Different modes of local anaesthetic administration have been applied, including the use of repeated bolus, continuous administration and, more recently, patient-controlled perineural infusions. This latter technique seems to be the preferred mode because it offers the advantage of tailoring the amount of local anaesthetics, mostly 0.2% ropivacaine, to the individual need and also maximizes the duration of infusion for a given volume of local anaesthetic. Although the preliminary reports indicate that lower extremity continuous blocks provide effective post-operative ambulatory analgesia and are safe, especially as a part of a multimodal approach, appropriate training in these techniques represents one of the most important limiting factors of the placement of perineural catheters. Additional research is required to determine the optimal conditions in which these techniques are indicated.