Do Continuous Femoral Nerve Blocks Affect the Hospital Length of Stay and Functional Outcome?

Abstract

To the Editor: Salinas et al. (1) demonstrated analgesic benefits associated with the use of continuous femoral nerve blocks compared to single femoral blocks for total knee replacement, similar to prior results from our group (2). However, they questioned the value of continuous blocks because there was no benefit in length of stay or the degree of flexion of the knee at 6 and 12 wk. This outcome was a fait accompli of the study design, and does not reflect the improvement patients experience from a continuous technique. Specifically, The surgeon and the principal physical therapist deciding the appropriate discharge time based on subjective criteria (Table 1) (1). The physical therapy program was limited to two sessions per day. It is unclear if patients were allowed to have physical therapy sessions on the day of surgery. Patients with continuous blocks better tolerated physical therapy sessions and therefore may have benefited from a more “aggressive” program, a key element of accelerated functional recovery (3). In our institution, we offer up to three physical therapy sessions starting on the day of surgery, and some of our patients undergoing total joint replacement go home on the same day of surgery. Outcome only considered the degree of knee flexion, and not the overall functional recovery as assessed by the SF36 (4). No attention was given to the physical therapy program after patient discharge. The authors considered a length of stay <3.7 days improbable, based on data published in a knee registry developed with surgeons performing an average of <10 joint replacements per year. Many orthopaedic surgeons performing a large number of total knee replacements report length of stays <3.7 days and in many cases of 23 h or less (5–7). Early functional recovery after joint replacement depends upon the surgical technique (traditional versus minimally invasive), the intensity of the physical therapy program (3), the preoperative condition of the patient (5), and the anesthesia and postoperative pain management techniques (8,9). The use of regional anesthesia is an important component of optimum functional recovery (10). Length of stay is also dependent upon reimbursement (in some states the hospital reimbursement is prorated up to 4 or 5 days) and pre-established pathways (surgeon and staff behaviors are very difficult to change). In conclusion, the study was not designed to allow any conclusion on the effects of continuous versus single femoral nerve blocks on length of stay and patient outcome. Jacques E. Chelly, MD, PhD, MBA Bruce Ben-David, MD Department of Anesthesiology Orthopaedic Anesthesia and Acute Interventional Perioperative Pain Divisions University of Pittsburgh Medical Center UPMC Presbyterian-Shadyside Hospital Pittsburgh, PA [email protected]