Perioperative Management of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is the leading sleep disordered breathing condition, with a prevalence rate of moderate to severe OSA of approximately 10-17% in the general population. We performed an Ovid-Medline search of all articles published up to August 2016. We included all articles providing updated evidence on epidemiology, pathophysiologic mechanisms and perioperative interventions. OSA is associated with a number of comorbidities and increased perioperative risks. Although in-laboratory polysomnography represents the gold-standard for diagnosis of OSA, it is costly and time-consuming. Anesthesiologists may screen patients for OSA through one of the available questionnaires, of which the snoring, tiredness, observed apnea, high blood pressure (STOP)-Body Mass Index, age, neck circumference and gender (Bang), STOP-bang questionnaire is the most externally validated. Although its sensitivity for the identification of mild OSA patients is 83.6%, its specificity is only 56.4%. OSA patients are associated with a higher risk of both difficult ventilation and intubation. However, practice guidelines refer to available guidelines for difficult airway management. Perioperative continuous positive airway pressure use may be of benefit since it has been reported to be associated with a reduction of both respiratory and cardiovascular complications and symptom relief. When feasible, regional anesthesia techniques and a multimodal analgesia approach should be adopted to reduce intraoperative and postoperative exposure to opioids. Preoperative screening of OSA patients is of relevance given the increased perioperative morbidity of these patients. Further studies are needed to provide conclusive data on which perioperative interventions are most effective at reducing this risk.

The prevalence of obstructive sleep apnea (OSA) has reached 1 billion people worldwide, implying significant risk for the perioperative setting as patients are vulnerable to cardiopulmonary complications, critical care requirement, and unexpected death. This review summarizes main aspects and considerations for the perioperative management of OSA, a condition of public health concern. Critical determinants of perioperative risk include OSA-related changes in upper airway anatomy with augmented collapsibility, diminished capability of upper airway dilator muscles to respond to airway obstruction, disparities in hypoxemia and hypercarbia arousal thresholds, and instability of ventilatory control. Preoperative OSA screening to identify patients at increased risk has therefore been implemented in many institutions. Experts recommend that in the absence of severe symptoms or additional compounding health risks, patients may nevertheless proceed to surgery, while heightened awareness and the adjustment of postoperative care is required. Perioperative caregivers should anticipate difficult airway management in OSA and be prepared for airway complications. Anesthetic and sedative drug agents worsen upper airway collapsibility and depress central respiratory activity, while the risk for postoperative respiratory compromise is further increased with the utilization of neuromuscular blockade. Consistently, opioid analgesia has proven to be complex in OSA, as patients are particularly prone to opioid-induced respiratory depression. Moreover, basic features of OSA, including intermittent hypoxemia and repetitive sleep fragmentation, gradually precipitate a higher sensitivity to opioid analgesic potency along with an increased perception of pain. Hence, regional anesthesia by blockade of neural pathways directly at the site of surgical trauma as well as multimodal analgesia by facilitating additive and synergistic analgesic effects are both strongly supported in the literature as interventions that may reduce perioperative complication risk. Health care institutions are increasingly allocating resources, including those of postoperative enhanced monitoring, in an effort to increase patient safety. The implementation of evidence-based perioperative management strategies is however burdened by the rising prevalence of OSA, the large heterogeneity in disease severity, and the lack of evidence on the efficacy of costly perioperative measures. Screening and monitoring algorithms, as well as reliable risk predictors, are urgently needed to identify OSA patients that are truly in need of extended postoperative surveillance and care. The perioperative community is therefore challenged to develop feasible pathways and measures that can confer increased patient safety and prevent complications in patients with OSA.

The frequency of metabolic and bariatric surgery (MBS) is increasing worldwide, with over 500,000 cases performed every year. Obstructive sleep apnea (OSA) is present in 35%-94% of MBS patients. Nevertheless, consensus regarding the perioperative management of OSA in MBS patients is not established. To provide consensus based guidelines utilizing current literature and, when in the absence of supporting clinical data, expert opinion by organizing a consensus meeting of experts from relevant specialties. The meeting was held in Amsterdam, the Netherlands. A panel of 15 international experts identified 75 questions covering preoperative screening, treatment, postoperative monitoring, anesthetic care and follow-up. Six researchers reviewed the literature systematically. During this meeting, the "Amsterdam Delphi Method" was utilized including controlled acquisition of feedback, aggregation of responses and iteration. Recommendations or statements were provided for 58 questions. In the judgment of the experts, 17 questions provided no additional useful information and it was agreed to exclude them. With the exception of 3 recommendations (64%, 66%, and 66% respectively), consensus (>70%) was reached for 55 statements and recommendations. Several highlights: polysomnography is the gold standard for diagnosing OSA; continuous positive airway pressure is recommended for all patients with moderate and severe OSA; OSA patients should be continuously monitored with pulse oximetry in the early postoperative period; perioperative usage of sedatives and opioids should be minimized. This first international expert meeting provided 58 statements and recommendations for a clinical consensus guideline regarding the perioperative management of OSA patients undergoing MBS.

Obstructive sleep apnea (OSA) is common in patients undergoing surgery. OSA, known or suspected, has been associated with significant perioperative adverse events, including severe neurologic injury and death. This study was undertaken to assess the legal consequences associated with poor outcomes related to OSA in the perioperative setting. A retrospective review of the legal literature was performed by searching 3 primary legal databases between the years 1991 and 2010 for cases involving adults with known or suspected OSA who underwent a surgical procedure associated with an adverse perioperative outcome. OSA had to be directly implicated in the outcome, and surgical mishaps (i.e., uncontrolled bleeding) were excluded. The adverse perioperative outcome had to result in a lawsuit that was then adjudicated in a court of law with a final decision rendered. Data were abstracted from each case regarding patient demographics, type of surgery, type and location of adverse event, associated anesthetic and opioid use, and legal outcome. Twenty-four cases met the inclusion criteria. The majority (83%) occurred in or after 2007. Patients were young (average age, 41.7 years), male (63%), and had a known diagnosis of OSA (96%). Ninety-two percent of cases were elective with 33.3% considered general procedures, 37.5% were ears, nose and throat procedures for the treatment of OSA, and 29.1% were considered miscellaneous interventions. Complications occurred intraoperatively (21%), in the postanesthesia care unit (33%), and on the surgical floors (46%). The most common complications were respiratory arrest in an unmonitored setting and difficulty in airway management. Immediate adverse outcomes included death (45.6%), anoxic brain injury (45.6%), and upper airway complications (8%). Overall, 71% of the patients died, with 6 of the 11 who suffered anoxic brain injury dying at an average of 113 days later. The use of opioids and general anesthetics was believed to play a role in 38% and 58% of cases, respectively. Verdicts favored the plaintiffs in 58% of cases and the defendants in 42%. In cases favoring the plaintiff, the average financial penalty was $2.5 million (±$2.3 million; range, $650,000--$7.7 million). Perioperative complications related to OSA are increasingly being reported as the central contention of malpractice suits. These cases can be associated with severe financial penalties. These data likely underestimate the actual medicolegal burden, given that most such cases are settled out of court and are not accounted for in the legal literature.