General anesthesia techniques reducing the time to satisfy phase I post-anesthesia care unit discharge criteria: Narrative review of randomized clinical trials and cohort studies studying unit bypass, supplemented with computer simulation

Abstract

We performed a narrative review of bypass of the phase I post-anesthesia care unit (PACU) following general anesthesia to gain insight into ways to reduce the time until patients are ready for PACU discharge following general anesthesia. Web of Science and PubMed literature searches were performed. Publications’ references and citations were examined. The Scale for the Assessment of Narrative Review Articles’ six components were satisfied. The 14 articles included 17 studies, with nearly all patients being adults. Most studies’ patients underwent outpatient surgery with an average surgical duration of less than 100 min . The studies applied several different, but similar, criteria to choose if patients bypass the PACU. Notably, 13 of 17 studies and all five with the largest observed bypass rates used some version of the White-Song fast-track bypass criteria. Propofol was used uniformly for induction of general anesthesia. Most studies included at least one antiemetic prophylactically, a local anesthetic administered by the surgeon, and a non-opioid analgesic. The six studies with the largest observed bypass rates used remifentanil or restricted use of intraoperative opioids. We then considered economics. While achievable PACU bypass rates are insufficient to reduce healthcare costs, reducing mean PACU time markedly can lower the nursing labor costs, the total time until the last patient exits the PACU, and the incidence of patients recovering in operating rooms because of unavailable PACU nurses or beds. We examined probability distributions of brief patient recovery times by using Gas Man, an uptake and distribution software program, simulating times until reaching constant incremental reductions (0.1  %) in vessel-rich concentrations of desflurane and sevoflurane once the vaporizer was set to zero. Results showed that simulated recovery from volatile anesthetics can have recovery times appearing log-normal, as seen empirically. Thus, patients already meeting discharge criteria upon PACU arrival can be the far-left fraction of one population of patients. The implication is that the narrative review results for PACU bypass provide insight into how to have more patients with very brief times to recovery. Therefore, future studies should quantify the effectiveness and economic benefits of anesthesia practitioners aiming not for PACU bypass, per se, but rather that the patients meet PACU discharge criteria by the 5–10 min after unit arrival when the practitioner has completed PACU handoff and finished documentation in the anesthesia record.