Abstract ID: A07

Abstract Title: Total Knee Arthroplasty as a 23-Hour Stay Procedure Using Ambulatory Perineural Local Anesthetic Infusion: A Prospective Feasibility Study

Poster Type: Poster


ABSTRACT BODY

Introduction: Criteria for home discharge following total knee arthroplasty (TKA) usually include the requirements (1) that patients’ pain is controlled with only oral analgesics that may be administered at home, and (2) that patients may ambulate at least 30 m so they may function at home (1). Consequently, the median duration of hospitalization following TKA in the US is 5 days (3). In contrast to IV opioids and epidural analgesia, perineural infusion does not require patients to remain hospitalized (4). Hospital stays may be shortened if perineural infusion (1) provides adequate analgesia without IV opioids or epidural analgesia, and (2) improves ambulation ability in the postoperative period. Potential benefits to individuals include a decreased risk of nosocomial infection, and improved patient analgesia and quality-of-life (5). For society, the potential cost-savings are enormous, with over 250,000 knee replacements performed annually at a cost of over $6 billion in the United States alone (3,6). Therefore, this prospective study was designed to investigate the feasibility of converting TKA into a 23-hour stay procedure using perineural femoral local anesthetic infusion and portable infusion pumps.

Methods: Preoperatively, after IRB approval and informed consent, patients free of cardiopulmonary disease received a femoral perineural catheter using a nerve stimulator and 8.9 cm, 17 g insulated needle (StimuCath, Arrow International, Reading, PA, USA). Intraoperatively, patients received a GA with sevoflurane/N2O/O2. Postoperatively, perineural ropivacaine, 0.2% (basal 8 mL/h, bolus 4 mL, lockout 30 min), was delivered with a portable electronic infusion pump (Pain Pump II, Stryker Instruments, Kalamazoo, MI, USA). Patients received scheduled Oxycontin (10 mg po BID) followed by oral and/or IV opioids, as needed. Patients were discharged home when they met specific, prospectively-defined discharge criteria (Table 1); as early as postoperative day (POD) 3 for the first phase (n=7) and POD 1 for the second phase (n=6). Patients were contacted each evening by phone, and their caretakers removed the catheters with instructions given over the phone in the evening of POD 4. Pain scores were recorded using a 0-10 numeric rating pain scale (NRS; 0 = no pain, 10=worst imaginable pain).

Results: Of the seven patients of the first phase who remained hospitalized until at least POD 3, four met discharge criteria on POD 1 and the remainder met criteria on POD 2. Of the subsequent 6 patients of the second phase, all met discharge criteria and were discharged home on POD 1. All patients from both phases underwent successful ambulatory perineural infusion until their catheters were removed in the evening of POD 4 (Fig. 1, Tables 1-2).

Conclusions: These results suggest that TKA may be performed as a 23-hour stay procedure using ambulatory perineural local anesthetic infusion. Additional data are required to define the appropriate subset of patients and assess the incidence of complications associated with this practice.

References: (1) J Orthop Sports Phys Ther’96;23:3. (2) Am J Phys Med Rehabil’95;74:294. (3) Stat Bull Metrop Insur Co’96;77:24. (4) Anesthesiology’04;100:395. (5) Emerg Infect Dis’01;7:174. (6) JAMA’98;279:847.

ATTACHED FILES



A07_Table 1.doc

A07_Table 2.doc

Reg Anesth Pain Med 2004; 29(2):A07