IMPACT OF ANAESTHETIC CHOICE ON TIME TO DISCHARGE FOR SAME-DAY DISCHARGE JOINTS

As total joint programs continue to move towards same-day discharge (SDD), patient flow and time to discharge are increasingly being recognized as key performance indicators. The primary objectives of this study were to determine the impact of the choice of anesthetics—particularly spinal drugs—on time to discharge after primary hip and knee replacement in an SDD arthroplasty program. After obtaining institutional research ethics board approval, a retrospective chart review was conducted within our arthroplasty program. During that period, which included COVID-19 slowdowns, a total of 693 patients underwent primary THA and TKA. Exclusion criteria included patients who failed SDD, were hospitalized for complications of the surgery within 90 days, had an ASA of greater than 3—since these patients are not great candidates for SDD—, were undergoing a bilateral surgery, or any cases where some patient or surgery data was missing. The resultant 261 cases were all performed by four fellowship-trained arthroplasty surgeons who have >50% of their joint replacement surgeries done as SDD. Baseline characteristics were recorded, and the anesthetic record was reviewed for the length of surgery, anesthetic drug and dose used, as well as perioperative complications. The time from the patient leaving the operating room (OR) to physiotherapy (PT) assessment, and the time from OR to final discharge were recorded. These were referred to as ambulation time and discharge time respectively. The patients' mean age and body mass index (BMI) were 65.14 ± 10.98 years (range 17–85) and 29.28 ± 5.69 kg/m2 (range 17.43–49.00), respectively. The median American Society of Anesthesia (ASA) score was 2 (interquartile range 2–3) with 152 TKA (58.2%), and 151 THA (57.9%). The mean age by gender was 64.03 ± 10.9 years for women and 66.82 ± 10.9 years for men. The ambulation time was significantly reduced in cases where hypobaric lidocaine was used in a spinal block compared to a spinal block with isobaric or hyperbaric bupivacaine—135.07 ± 61.87 min, 305.00 ± 111.54 min, 226.82 ± 80.15 min respectively—(p ± 49.15 min, 426.11 ± 93.87 min, 374.94 ± 77.95 min, 370.90 ± 89.95 min respectively—(p ± 107.37 min—(p=0.0815), as well as a trend toward a lower perioperative conversion rate to general anesthesia compared to isobaric or hyperbaric bupivacaine (p = 0.062, p=0.092). No cases of transient neurologic symptoms were reported. In both hip and knee arthroplasty, patients receiving a hypobaric lidocaine spinal block experienced a significantly reduced time to discharge and shortened ambulation time compared to other anesthetics. Surgical teams should feel confident in using hypobaric lidocaine during spinal anesthesia as it is both safe and efficacious in SDD total joint arthroplasty programs.