Undersedation During Total Hip Arthroplasty Reduction Results in Worse Patient Outcomes

Total hip arthroplasty (THA) dislocation is a common reason for presentation to the emergency department (ED) postoperatively. Prior literature has shown that propofol conscious sedation provides the fewest complications and the shortest time to reduction. However, we are aware of no prior reports exploring sedative dosing regimens. We hypothesized that "undersedated" patients would have worse outcomes compared to appropriately sedated patients based on dose.

This is a retrospective review of isolated propofol conscious sedation performed in the ED for closed reduction of THA dislocations from 2013 to 2019. Prior authors have used at least 0.5 mg/kg/dose for sedation with propofol. Therefore, to allow a 10% rounding error, a dose of less than 0.45 mg/kg/dose was considered undersedated. Demographic information was collected and outcomes including sedation time, number of doses, complications, and successful reductions were analyzed in univariable and multivariable analyses.

A total of 79 THAs were included for analysis with mean age 65.5 (16.2) years and weight 84.1 (21.3) kg. Thirty-seven (46.8%) patients had undergone revision surgery and 44 (55.7%) previously had a dislocation. A total of 39 patients were undersedated. There was no significant difference in demographics or arthroplasty-specific variables between undersedated and "protocol" sedation patients. In multivariable analysis, undersedated patients had significantly longer sedation time (P = .020), more re-doses (by mean 3 doses; P < .001), and greater total dose (P = .002). These patients were also more likely to have failed ED closed reduction (10.3% vs 0.0%; P = .038). One complication of a skin tear from countertraction was observed in an undersedated patient.

Historically, conscious sedation for THA dislocations has been the responsibility of the emergency room clinician. In consideration of our outcomes, we advocate for a multidisciplinary team to create a sedation protocol, emphasizing the need to maintain a dosing regimen of 0.5 mg/kg/dose to improve the care of THA patients.