REGIONAL ANESTHESIA SECTION EDITOR TERESE T. HORLOCKER In with the New, Out with the Old? Comparison of Two Approaches for Psoas Compartment Block Stephen Mannion, MRCPI, FCARCSI, Sheila O’Callaghan, FCARCSI, Mary Walsh, FCARCSI, Damian B. Murphy, FCARCSI, MD, and George D. Shorten, FCARCSI, PhD Department of Anaesthesia and Intensive Care, Cork University Hospital; St. Mary’s Orthopaedic Hospital; and University College, Cork, Ireland We compared the approaches of Winnie and Capdevila for psoas compartment block (PCB) performed by a sin- gle operator in terms of contralateral spread, lumbar plexus blockade, and postoperative analgesic efficacy. Sixty patients underwent PCB (0.4 mL/kg levobupiva- caine 0.5%) and subsequent spinal anesthesia for pri- mary joint arthroplasty (hip or knee) in a prospective, double-blind study. Patients were randomly allocated to undergo PCB by using the Capdevila (group C; n = 30) or a modified Winnie (group W; n = 30) approach. Contralateral spread and lumbar plexus blockade were assessed 15, 30, and 45 min after PCB. Contralateral spread (bilateral from T4 to S5) and femoral and lateral cutaneous nerve block were evaluated by sensory test- ing, and obturator motor block was assessed. Bilateral anesthesia occurred in 10 patients in group C and 12 patients in group W (P = 0.8). Blockade of the femoral, lateral cutaneous, and obturator nerves was 90%, 93%, and 80%, respectively, for group C and 93%, 97%, and 90%, respectively, for group W (P  0.05). No differ- ences were found in PCB procedure time, pain scores, 24-h morphine consumption, or time to first morphine analgesia. (Anesth Analg 2005;101:259 –64) W innie et al. (1) first described a posterior approach for lumbar plexus block. Inadvertent epidural (2) and spinal (3) anesthesia have occurred with this approach, and this has led to concerns regarding its use (4). Bilateral anesthesia has also complicated alternative ap- proaches to lumbar plexus or psoas compartment block (PCB) as described by Chayen et al. (5) and Dekrey (6). The invariable medial needle redirection with Winnie’s technique to locate the lumbar plexus may be a factor in bilateral anesthesia (1,7). Capdevila et al. (7) revisited Winnie’s landmarks and modified the approach to permit maintenance of a perpendic- ular needle orientation. They found no cases of bi- lateral anesthesia. A radiographic study of this tech- nique demonstrated epidural spread of contrast medium in only 2% of patients (8). This incidence is less than the commonly quoted incidences of 10%– 20% for Winnie’s approach (9). Comparison of quoted incidences of bilateral anesthesia secondary to PCB in the literature suggests that the incidence is dependent on the approach used (10). However, accurate determination of the incidence of bilateral anesthesia after PCB is complicated by a number of factors. Assessment of bilateral blockade has been variable in terms of timing and extent (2,6,7). Radiographic imaging does not provide an indication of spread over time (8). Finally, incidences of bilateral anesthesia compare PCB performed by different oper- ators. Identification of anatomical surface landmarks is extremely variable among anesthesiologists (11,12). The increasing use of nerve stimulation in peripheral nerve block techniques has resulted in a modification of Winnie’s original technique, and stimulation of the fem- oral nerve, rather than paresthesia, is now sought (2,13). We therefore performed a modified Winnie technique, seeking femoral nerve stimulation, and standardized our medial needle redirection as 15°. Our aims were to com- pare a modified Winnie technique with Capdevila’s ap- proach for PCB performed by the same operator in terms of incidence of contralateral spread, extent of lumbar plexus blockade, and efficacy of postoperative analgesia after primary total hip or knee arthroplasty. Methods With institutional ethics committee approval and writ- ten informed consent, 60 ASA I–III patients scheduled Presented in part at the annual meeting of the American Society of Anesthesiologists, Las Vegas, NV, October 23-27, 2004. Accepted for publication December 2, 2004. Address correspondence to Stephen Mannion, MRCPI, FCARCSI, De- partment of Anesthesia and Intensive Care, Cork University Hospital, Cork, Ireland. Address e-mail to mannionstephen@hotmail.com. No re- prints will be available. DOI: 10.1213/01.ANE.0000153866.38440.43 ©2005 by the International Anesthesia Research Society 0003-2999/05 Anesth Analg 2005;101:259–64 259