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Background: Obstructive sleep apnea has been associated with postoperative complications. We hypothesized that postoperative autotitrating positive airway pressure (APAP) applied to patients at high risk for obstructive sleep apnea would shorten hospital stay and reduce postoperative complications., Methods: Included were patients aged 18 to 100 years scheduled for elective total knee or hip arthroplasty who were able to give informed consent. Patients without contraindication to positive airway pressure therapy were divided into a high- or low-risk group on the basis of the Flemons sleep apnea clinical score. Low-risk patients received standard care. High-risk patients were randomized to receive standard care or standard care plus postoperative APAP. All patients were administered a predismissal cardiorespiratory sleep study. The primary end point was length of stay, and secondary end points were a range of postoperative complications., Results: One hundred thirty-eight patients were enrolled in the study (52 in the low-risk group, 86 in the high-risk group). Within the high-risk group, 43 were randomized to standard care and 43 to standard care plus postoperative APAP. There were no significant differences in the length of stay (P=.65) or any of the secondary end points between the randomized groups. On subgroup analysis of patients with an apnea-hypopnea index of ≥15, patients randomized to APAP had a longer postoperative stay (median, 5 vs 4 days; P=.02)., Conclusions: The role for empirical postoperative APAP requires further study, but the findings did not show benefit for APAP applied postoperatively to positive airway pressure-naive patients at high risk for sleep apnea.

Background: Obstructive sleep apnoea (OSA) is often undiagnosed before elective surgery and may predispose patients to perioperative complications., Methods: A literature search of PubMed-Medline, Web of Science, Scopus, EMBASE, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials up to November 2010 was conducted. Our search was restricted to cohort or case-control studies in adults diagnosed with OSA by screening questionnaire, oximetry, or polysomnography. Studies without controls, involving upper airway surgery, and with OSA diagnosed by ICD-9 codes alone were excluded. The primary postoperative outcomes were desaturation, acute respiratory failure (ARF), reintubation, myocardial infarction/ischaemia, arrhythmias, cardiac arrest, intensive care unit (ICU) transfer, and length of stay., Results: Thirteen studies were included in the final analysis (n=3942). OSA was associated with significantly higher odds of any postoperative cardiac events [45/1195 (3.76%) vs 24/1420 (1.69%); odds ratio (OR) 2.07; 95% confidence interval (CI) 1.23-3.50, P=0.007] and ARF [33/1680 (1.96%) vs 24/3421 (0.70%); OR 2.43, 95% CI 1.34-4.39, P=0.003]. Effects were not heterogeneous for these outcomes (I(2)=0-15%, P>0.3). OSA was also significantly associated with higher odds of desaturation [189/1764 (10.71%) vs 105/1881 (5.58%); OR 2.27, 95% CI 1.20-4.26, P=0.01] and ICU transfer [105/2062 (5.09%) vs 58/3681 (1.57%), respectively; OR 2.81, 95% CI 1.46-5.43, P=0.002]. Both outcomes showed a significant degree of heterogeneity of the effect among studies (I(2)=57-68%, P<0.02). Subgroup analyses had similar conclusions as main analyses., Conclusions: The incidence of postoperative desaturation, respiratory failure, postoperative cardiac events, and ICU transfers was higher in patients with OSA.

Clinicians are becoming more aware of the risks of sleep deprivation and unrecognized sleep-disordered breathing in hospitalized patients, most importantly in those patients planning to undergo surgical procedures. Polysomnography is difficult to perform in the hospital setting, such that actigraphy or urinary metabolites of melatonin are often used as surrogate measures, and show that sleep is markedly impaired. Patients in the medical intensive care unit with sepsis or requiring mechanical ventilation may show complete absence of the normal circadian rhythm pattern, and many centers have initiated sleep-enhancement protocols. In postoperative patients, rapid-eye-movement sleep is nearly obliterated, especially in the first 1-2 days after surgery, and this appears closely related to the use of high-dose opioids. Sleep-disordered breathing is common in postoperative patients, and tools such as the Sleep Apnea Clinical Score or the STOP-BANG (Snoring, Tiredness, Observed apnea, and high blood Pressure - Body mass index, Age, Neck circumference, and Gender) questionnaires have been utilized to predict the possibility of obstructive sleep apnea (OSA) and postoperative respiratory complications. Protocols to evaluate patients that determine the need and process for positive-airway-pressure treatment in the hospital patient with OSA are being developed. An obstructive apnea systematic intervention strategy protocol to deal with patients with suspected OSA can help guide diagnostic and therapeutic decision making. Hospitals that are proactive in the development of protocols for identification and management of patients with sleep-disordered breathing are likely to be rewarded with reduced complications and costs, and the issue is sure to be incorporated in future pay-for-performance evaluations.

Background: Patients with obstructive sleep apnea are at risk for perioperative morbidity. The authors used a screening prediction model for obstructive sleep apnea to generate a sleep apnea clinical score (SACS) that identified patients at high or low risk for obstructive sleep apnea. This was combined with postanesthesia care unit (PACU) monitoring with the aim of identifying patients at high risk of postoperative oxygen desaturation and respiratory complications., Methods: In this prospective cohort study, surgical patients with a hospital stay longer than 48 h who consented were enrolled. The SACS (high or low risk) was calculated; all patients were monitored in the PACU for recurrent episodes of bradypnea, apnea, desaturations, and pain-sedation mismatch. All patients underwent pulse oximetry postoperatively; complications were documented. Chi-square, two-sample t test, and logistic regression were used for analysis. The oxygen desaturation index (number of desaturations per hour) was calculated. Oxygen desaturation index and incidence of postoperative cardiorespiratory complications were primary endpoints., Results: Six hundred ninety-three patients were enrolled. From multivariable logistic regression analysis, the likelihood of a postoperative oxygen desaturation index greater than 10 was increased with a high SACS (odds ratio = 1.9, P < 0.001) and recurrent PACU events (odds ratio = 1.5, P = 0.036). Postoperative respiratory events were also associated with a high SACS (odds ratio = 3.5, P < 0.001) and recurrent PACU events (odds ratio = 21.0, P < 0.001)., Conclusions: Combination of an obstructive sleep apnea screening tool preoperatively (SACS) and recurrent PACU respiratory events was associated with a higher oxygen desaturation index and postoperative respiratory complications. A two-phase process to identify patients at higher risk for perioperative respiratory desaturations and complications may be useful to stratify and manage surgical patients postoperatively.

Study Objectives: Obstructive sleep apnea (OSA) has been associated with increased perioperative morbidity and mortality. We initiated a protocol designed to screen patients preoperatively and monitor them postoperatively. The goal was to identify patients who were at risk for oxygen desaturation after discharge from the postanesthesia recovery room (PACU)., Methods: Patients without previously diagnosed OSA presenting to the preoperative evaluation clinic were assessed over a 10.5-month period using a validated prediction rule to identify patients thought to be at high risk of OSA (sleep apnea clinical score, SACS > or = 15). Following surgery, patients were monitored in the PACU for significant respiratory events: apnea, increased FiO2 requirement, pain-sedation mismatch, or episodes of desaturation. Patients were placed in 3 groups based on their SACS and the presence or absence of recurrent PACU respiratory events (group 1: SACS < 15, no recurrent events; group 2: SACS > or =15, no recurrent events; and group 3: SACS > or = 15, recurrent events.) The number of oxygen desaturations > or = 4% per hour, the oxygen desaturation index (ODI), was calculated for each patient for 24 to 48 hours after PACU discharge. An ODI > 10 was the threshold chosen to indicate a high frequency of oxygen desaturation., Results: The percentage of patients with ODI > 10 differed significantly across the 3 study groups (12%, 37%, and 57%, for groups 1-3, p = 0.005). Mean ODI in group 1 was significantly different from groups 2 and 3 (5.8 compared to 10.0 group 2 and 11.4 group 3 with p = 0.001)., Conclusions: We have shown that combining preoperative screening is useful for identifying patients at risk for oxygen desaturation after PACU discharge.

Objective: To identify and assess the impact of postoperative complications in patients with unrecognized or known obstructive sleep apnea syndrome (OSAS) undergoing hip replacement or knee replacement compared with control patients undergoing similar operations. Although OSAS is a risk factor for perioperative morbidity, data quantifying the magnitude of the problem in patients undergoing non-upper airway operations are limited., Patients and Methods: This retrospective, case-control study from a single academic medical institution included patients diagnosed as having OSAS between January 1995 and December 1998 and undergoing hip or knee replacement within 3 years before or anytime after their OSAS diagnosis. Patients with OSAS were subcategorized as having the diagnosis either before or after the surgery and also, regardless of time of diagnosis, by whether they were using continuous positive airway pressure (CPAP) prior to hospitalization. Matched controls were patients without OSAS undergoing the same operation. Interventions were defined specifically as administration of a particular treatment in the context of each complication, eg, supplemental oxygen, implementation of additional monitoring such as oximetry for hypoxemia, or transfer to the intensive care unit (ICU) for cardiac ischemia concerns. Postoperative complications were assessed for all patients in the different categories and included respiratory events such as hypoxemia, acute hypercapnia, and episodes of delirium. Serious complications were noted separately, including unplanned ICU days, reintubations, and cardiac events. The length of hospital stay was also tabulated., Results: There were 101 patients with the diagnosis of OSAS in this study and 101 matched controls. Thirty-six patients had their joint replacement before OSAS was diagnosed, and 65 had surgery after OSAS was diagnosed. Of the latter 65 patients, only 33 were using CPAP at home preoperatively. Complications were noted in 39 patients (39%) in the OSAS group and 18 patients (18%) in the control group (P=.001). Serious complications occurred in 24 patients (24%) in the OSAS group compared with 9 patients (9%) in the control group (P=.004). Hospital stay was significantly longer for the OSAS patients at a mean +/- SD of 6.8 +/- 2.8 days compared with 5.1 +/- 4.1 days for the control patients (P<.007)., Conclusion: Adverse postoperative outcomes occurred at a higher rate in patients with a diagnosis of OSAS undergoing hip or knee replacement compared with a group of matched control patients.