Post-Anesthesia Care Unit Duration After Total Hip Arthroplasty Under Spinal Anesthesia in Routine Hospital Practice: A Comparison with Contemporary Arthroplasty Literature

Background: Post-anesthesia care unit (PACU) duration after total hip arthroplasty (THA) is relevant for ward transfer, early mobilization, and perioperative flow, but is inconsistently reported as a distinct recovery outcome. This study evaluated PACU duration after primary THA under spinal anesthesia in routine hospital-based practice and interpreted the observed duration in relation to contemporary arthroplasty literature. Methods: This retrospective observational cohort study included adult patients undergoing primary THA under spinal anesthesia within two units of a regional hospital. PACU duration was defined as time from PACU arrival until discharge to the orthopedic ward. Demographic, anesthetic, perioperative, and recovery variables were extracted from electronic medical records. Univariate analyses and multivariable linear regression were used to explore factors associated with PACU duration. A focused contextual literature comparison was performed to interpret the observed duration in relation to reported early recovery endpoints, with direct comparison anchored to conventional PACU or recovery-room intervals before ward transfer or immediate pathway progression. Results: Ninety-seven of 150 screened patients were included. Mean PACU duration was 162.3 ± 58.5 min. PACU duration was numerically longer in Unit A than Unit S, but the difference was not statistically significant. Reported early recovery endpoints in the literature were heterogeneous. In univariate analysis, male sex and exploratory spinal local anesthetic dose > 13 mg were associated with longer PACU duration. In multivariable analysis, male sex remained associated with longer PACU duration, whereas spinal dose was not independently associated when analyzed as a continuous variable. Conclusions: PACU duration after THA under spinal anesthesia should be interpreted as a multifactorial, workflow-sensitive outcome rather than a purely anesthetic recovery measure. Differences in discharge criteria, recovery pathways, and endpoint definitions limit direct comparison across studies. PACU duration may be most meaningful as an operational recovery and flow indicator within broadly comparable clinical settings.