Abstract ID: A12
Abstract Title: Obturator Nerve Blockade as a Rescue Technique
Poster Type: Poster
ABSTRACT BODY
Obturator Nerve Blockade as a Rescue Technique
Introduction:
Winne first described the inguinal paravascular technique of lumbar plexus anesthesia, known as the “3 in 1 block,” in 1973 [1]. Blockade of the lateral femoral cutaneous and obturator nerves was thought to occur via cephalad and lateral spread of local anesthetic. Recent studies have suggested that the local anesthetic spreads unpredictably in lateral, caudal, and medial directions, often resulting in inadequate obturator nerve block [2]. McNamee et al. have reported the success of directed obturator nerve block, combined with femoral and sciatic nerve blocks, for reducing post-operative narcotic requirements for total knee arthroplasty [3]. This case series documents the use of directed obturator nerve block as a salvage technique for various lower extremity surgeries in which regional anesthesia was used as a component of postoperative pain management.
Case Report:
The following cases represent ASA physical status class I–III individuals scheduled to undergo various lower extremity surgical procedures under general anesthesia. All cases had sciatic and/or femoral nerve blocks placed preoperatively for postoperative pain management. Despite the verified presence of continued blockade within the expected distribution of the sciatic and/or femoral nerves, these patients still experienced significant discomfort in the immediate postoperative period. All eventually underwent directed obturator nerve block with a marked reduction in verbal analog pain scores (VAS) as reported by postoperative nursing personnel. The following table is a summary of these cases:
Insert Table
Discussion:
The preceding cases describe obturator nerve block used for postoperative rescue analgesia. The reduction in VAS corresponds with the decreased morphine requirement reported by McNamee et al. for total knee arthroplasty. Our cases demonstrate several other orthopedic surgeries in which obturator nerve block was a substantial adjunct in postoperative pain management. Further research is necessary to predict which patients and procedures would benefit from obturator nerve block.
References:
1. Winne AP, Ramamurthy S, Durrani Z. The inguinal paravascular technique for lumbar plexus anesthesia:” The 3-in-1 block”. Anes Analg 1973;52:989-96.
2. Marhofer S, Christian N, Sitzwohl C, Kapral S. Magnetic resonance imaging of the distribution of local anesthetic during the three-in-one block. Anes Analg 2000;90:119-24.
3. McNamee DA, Parks L, Milligan KR, Post-operative analgesia following total knee replacement: an evaluation of the addition of an obturator nerve block to combined femoral and sciatic nerve block. Acta Anaesthesiol Scand 2002;46:95-99.
ATTACHED FILES
A12_Table 1.xls
Reg Anesth Pain Med 2004; 29(2):A12