Outcomes and Safety Among Patients With Obstructive Sleep Apnea Undergoing Cancer Surgery Procedures in a Freestanding Ambulatory Surgical Facility
Authors: Szeto Betsy , Vertosick Emily A. , Ruiz Karin , Tokita Hanae , Vickers Andrew , Assel Melissa , Simon Brett A. , Twersky Rebecca S. 
Published: April 2019

BACKGROUND:
Patients with obstructive sleep apnea (OSA) may be at increased risk for serious perioperative complications. The suitability of ambulatory surgery for patients with OSA remains controversial, and several national guidelines call for more evidence that assesses clinically significant outcomes. In this study, we investigate the association between OSA status (STOP-BANG risk, or previously diagnosed) and short-term outcomes and safety for patients undergoing cancer surgery at a freestanding ambulatory surgery facility.

METHODS:
We conducted a retrospective analysis of all patients having surgery at the Josie Robertson Surgery Center, a freestanding ambulatory surgery facility of the Memorial Sloan Kettering Cancer Center. Surgeries included more complex ambulatory extended recovery procedures for which patients typically stay overnight, such as mastectomy, thyroidectomy, and minimally invasive hysterectomy, prostatectomy, and nephrectomy, as well as typical outpatient surgeries. Both univariate and multivariable analyses were used to assess the association between OSA risk and transfer to the main hospital, urgent care center visit, and hospital readmission within 30 days postoperatively (primary outcomes) and length of stay and discharge time (secondary outcomes). Multivariable models were adjusted for age, American Society of Anesthesiologists score, robotic surgery, and type of anesthesia (general or monitored anesthesia care) and also adjusted for surgery start time for length of stay and discharge time outcomes. χ2 tests were used to assess the association between OSA risk and respiratory events and device use.

RESULTS:
Of the 5721 patients included in the analysis, 526 (9.2%) were diagnosed or at moderate or high risk for OSA. We found no evidence of a difference in length of stay when comparing high-risk or diagnosed patients with OSA to low- or moderate-risk patients whether they underwent outpatient (P = .2) or ambulatory extended recovery procedures (P = .3). Though a greater frequency of postoperative respiratory events were reported in high-risk or diagnosed patients with OSA compared to moderate risk (P = .004), the rate of hospital transfer was not significantly different between the groups (risk difference, 0.78%; 95% CI, –0.43% to 2%; P = .2). On multivariable analysis, there was no evidence of increased rate of urgent care center visits (adjusted risk difference, 1.4%; 95% CI, –0.68% to 3.4%; P = .15) or readmissions within 30 days (adjusted risk difference, 1.2%; 95% CI, –0.40% to 2.8%; P = .077) when comparing high-risk or diagnosed OSA to low- or moderate-risk patients. Based on the upper bounds of the CIs, a clinically relevant increase in transfers, readmissions, and urgent care center visits is unlikely.

CONCLUSIONS:
Our results contribute to the body of evidence supporting that patients with moderate-risk, high-risk, or diagnosed OSA can safely undergo outpatient and advanced ambulatory oncology surgery without increased health care burden of extended stay or hospital admission and avoiding adverse postoperative outcomes. Our results support the adoption of several national OSA guidelines focusing on preoperative identification of patients with OSA and clinical pathways for perioperative management and postoperative monitoring.