Anesthesia (9)
Authors: Stevens Robert D. , Van Gessel Elisabeth , Flory Nicolas , Fournier Roxane , Gamulin Zdravko 
Published: September 2010

Lumbar plexus clock reduces pain and blood loss associated with total hip arthroplasty. (Hôpitaux Universitaires de Genéve, Geneva, Switzerland) Anesthesiology 2000;93:115–121.

In this study, 60 patients undergoing total hip arthroplasty were randomized to receive general anesthesia with (plexus group, n = 30) or without (control group, n = 30) a posterior lumbar plexus block. The block was performed after induction using a nerve stimulator, and 0.4 mL/kg bupivacaine, 0.5%, with epinephrine was injected. General anesthesia was standardized, and supplemental fentanyl was administered per hemodynamic guidelines. Postoperative pain and patient‐controlled intravenous morphine use were serially assessed for 48 h. The proportion of patients receiving supplemental fentanyl intraoperatively was more than 3 times greater in the control group (20 of 30 vs. 6 of 29, P = 0.001). In the postanesthesia care unit, a greater than fourfold reduction in pain scores was observed in the plexus group and “rescue” morphine boluses were administered 10 times less frequently. Pain scores and morphine consumption remained significantly lower in the plexus group until 6 h after randomization. Operative and postoperative (48 h) blood loss was decreased modestly in the treated group. Epidural‐like distribution of anesthesia occurred in 3 of 28 plexus group patients, but no other side effects were noted. Conclude that posterior lumbar plexus block provides effective analgesia for total hip arthroplasty, reducing intraoperative and postoperative opioid requirements. Blood loss during and after the procedure is diminished. Epidural anesthetic distribution should be anticipated in a minority of cases.

Comment by Alan David Kaye, MD, PhD.

The benefits of regional anesthetic techniques are well established for patients undergoing total hip arthroplasty. For example, it is common knowledge to the clinical anesthesiologist that regional anesthesia results in reduced blood loss as well as a reduction in thromboembolic events postoperatively. This interesting study considered a posterior lumbar plexus block since a significant portion of the hip is innervated via branches of the lumbar plexus. A randomized, double‐blinded trial of 60 consecutive patients undergoing total hip arthroplasty under general anesthesia was performed. Thirty patients had general anesthesia alone and 30 patients had general anesthesia with the lumbar plexus block. Pain scores and morphine consumption postoperatively were evaluated over a 48‐h period. Patients in the control group required supplemental narcotic (20/30) versus those in the lumbar plexus block group (6/30). No BIS monitor was employed simply with the end point of additional analgesic being an increase in blood pressure or heart rate greater than 130% of the baseline. Epidural‐like distribution of anesthesia occurred in 3 of 28 patients receiving the block. Incidence of nausea and vomiting was similar in both groups and pain scores were significantly lower until the 6‐h period postoperatively. There was a block‐associated reduction in hemorrhage. These results are not surprising; however, it would be unlikely that this block would be done in a repeated series and the authors describe a continuous catheter‐based technique, which they have presented in abstract form for longer‐term postoperative pain relief. The associated complications with this block must be weighed with these positive and predictable findings. The complexity of proper placement of this block compared with other regional techniques and its potential side effects would make this block difficult to implement in the operating room. The authors should be complemented for this study and great consideration for its potential benefits in clinical practice should be considered.