Postoperative hypoxemia in morbidly obese patients with and without obstructive sleep apnea undergoing laparoscopic bariatric surgery
ABSTRACT The increased incidence of morbid obesity has resulted in an increase of bariatric surgical procedures. Obstructive sleep apnea (OSA) is a commonly encountered comorbidity in morbidly obese patients. Sedatives, analgesics, and anesthetics alter airway tone, and airway obstruction and death have been reported in patients with OSA after minimal doses of sedatives and anesthetics, yet there is a lack of consensus regarding the care of these patients. In this study, we sought to determine whether obese patients with polysomnography-confirmed diagnosis of OSA were at significantly greater risk for postoperative hypoxemic episodes in the first 24 h after laparoscopic bariatric surgery than morbidly obese patients without a diagnosis of OSA.
Adult subjects (Body Mass Index, 35-75 kg/m(2)) scheduled to undergo laparoscopic bariatric surgery were studied. A finger pulse oximetry probe was placed preoperatively and oxygen saturation (Spo(2)) was recorded continuously. All subjects underwent preoperative polysomnography testing within 4 wk of surgery. Anesthetic management was standardized, using propofol for induction and desflurane and remifentanil for maintenance of anesthesia. Patient-controlled analgesia programmed to deliver morphine, 1 mg. every 10 minutes, was used for pain management postoperatively. Hypoxemic episodes were scored as Spo(2) >4% below the polysomnography study baseline and lasting for more than 10 s.
Eight men and 32 women were enrolled and 1 subject had incomplete data. Thirty-one of the 40 subjects had polysomnography-confirmed OSA. Eight subjects used home continuous positive airway pressure devices nightly, and six of these used their device postoperatively. Preoperatively, subjects with OSA had lower nadir Spo(2) during the polysomnography study and a larger number had an apnea/hypopnea index >10 episodes per hour compared with the non-OSA group. In the first 24 h postoperatively, there was no difference in the median Spo(2) with and without oxygen therapy, between OSA and non-OSA groups. The number of episodes of oxygen desaturation >4% below the polysomnography study baseline value and the mean number of desaturation episodes per hour did not differ between the groups.
In morbidly obese subjects, in the first 24 h after laparoscopic bariatric surgery, OSA does not seem to increase the risk of postoperative hypoxemia. Our data confirm that morbidly obese subjects, with or without OSA, experience frequent oxygen desaturation episodes postoperatively, despite supplemental oxygen therapy suggesting that perioperative management strategies in morbidly obese patients undergoing laparoscopic bariatric surgery should include measures to prevent postoperative hypoxemia.
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ABSTRACT: To determine whether a diagnosis of obstructive sleep apnea (OSA) imparts an increased risk of postoperative respiratory failure, cardiac events, and intensive care unit (ICU) transfer than patients with no OSA diagnosis. Systematic review and meta-analysis. Academic Veterans Affairs Medical Center. PubMed, EMBASE, CINAHL, and ISI Web of Knowledge databases were searched through April 2013 for studies that examined the relationship between OSA and postoperative respiratory and cardiac complications among adults. Either fixed or random-effects models were used to calculate the pooled risk estimates. Sensitivity analysis was conducted to examine the robustness of pooled outcomes. Seventeen studies with a total of 7,162 patients were included. Overall, OSA was associated with significant increase in risk of respiratory failure [odds ratio (OR) 2.42; 95% confidence intervals (CI) 1.53 - 3.84; P = 0.0002] and cardiac events postoperatively (OR = 1.63; 95% CI 1.16 - 2.29; P = 0.005). Heterogeneity was low for these outcomes (I(2) = 5% and 0%, respectively). ICU transfer occurred also more frequently in patients with OSA (OR 2.46; 95% CI 1.29 - 4.68; P = 0.006). These results did not materially change in the sensitivity analyses according to various inclusion criteria. Surgical patients with OSA are at increased risk of postoperative respiratory failure, cardiac events, and ICU transfer. Published by Elsevier Inc.Journal of Clinical Anesthesia 10/2014; DOI:10.1016/j.jclinane.2014.05.010 · 1.21 Impact Factor
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ABSTRACT: Obstructive sleep apnea (OSA) is a commonly encountered comorbid condition in patients undergoing surgery and is associated with a greater risk of postoperative adverse events. Our objective in this review was to investigate the effectiveness of continuous positive airway pressure (CPAP) in reducing the risk of postoperative adverse events in patients with OSA undergoing surgery, the perioperative Apnea-Hypopnea Index (AHI), and the hospital length of stay (LOS). We performed a systematic search of the literature databases. We reviewed the studies that included the following: (1) adult surgical patients (>18 years old) with information available on OSA; (2) patients using either preoperative and/or postoperative CPAP or no-CPAP; (3) available reports on postoperative adverse events, preoperative and postoperative AHI, and LOS; and (4) all published studies in English including case series. Six studies that included 904 patients were eligible for the meta-analysis. The meta-analysis for postoperative adverse events was performed in 904 patients (CPAP: n = 471 vs no-CPAP: n = 433; adverse events: 134 vs 133; P = 0.19). There was no significant difference in the postoperative adverse events between the 2 groups. The preoperative baseline AHI without CPAP was reduced significantly with postoperative use of CPAP (preoperative AHI versus postoperative AHI, 37 ± 19 vs 12 ± 16 events per hour, P < 0.001). LOS showed a trend toward significance in the CPAP group versus the no-CPAP group (4.0 ± 4 vs 4.4 ± 8 days, P = 0.05). Our review suggests that there was no significant difference in the postoperative adverse events between CPAP and no-CPAP treatment. Patients using CPAP had significantly lower postoperative AHI and a trend toward shorter LOS. There may be potential benefits in the use of CPAP during the perioperative period.Anesthesia and analgesia 05/2015; 120(5):1013-23. DOI:10.1213/ANE.0000000000000634 · 3.42 Impact Factor
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ABSTRACT: The perioperative use and relevance of protective ventilation in surgical patients is being increasingly recognized. Obesity poses particular challenges to adequate mechanical ventilation in addition to surgical constraints, primarily by restricted lung mechanics due to excessive adiposity, frequent respiratory comorbidities (i.e. sleep apnea, asthma), and concerns of postoperative respiratory depression and other pulmonary complications. The number of surgical patients with obesity is increasing, and facing these challenges is common in the operating rooms and critical care units worldwide. In this review we summarize the existing literature which supports the following recommendations for the perioperative ventilation in obese patients: (1) the use of protective ventilation with low tidal volumes (approximately 8 mL/kg, calculated based on predicted -not actual- body weight) to avoid volutrauma; (2) a focus on lung recruitment by utilizing PEEP (8-15cmH2O) in addition to recruitment maneuvers during the intraoperative period, as well as incentivized deep breathing and noninvasive ventilation early in the postoperative period, to avoid atelectasis, hypoxemia and atelectrauma; and (3) a judicious oxygen use (ideally less than 0.8) to avoid hypoxemia but also possible reabsorption atelectasis. Obesity poses an additional challenge for achieving adequate protective ventilation during one-lung ventilation, but different lung isolation techniques have been adequately performed in obese patients by experienced providers. Postoperative efforts should be directed to avoid hypoventilation, atelectasis and hypoxemia. Further studies are needed to better define optimum protective ventilation strategies and analyze their impact on the perioperative outcomes of surgical patients with obesity.BMC Anesthesiology 04/2015; 15(1):56. DOI:10.1186/s12871-015-0032-x · 1.33 Impact Factor