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 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.

https://www.mayoclinicproceedings.org/article/S0025-6196(11)62108-3/pdf

Postoperative complications in patients with obstructive sleep apnea syndrome undergoing hip or knee replacement: a case-control study

Background Obstructive sleep apnea (OSA) is present in a significant proportion of the population, but the majority of patients remain undiagnosed It is crucial that anesthesiologists and surgeons recognize the increased perioperative risks associated with undiagnosed OSA We present a systematic review of the literature on the perioperative management of surgical patients with OSA Methods The scope of this review is restricted to publications in all surgical specialties and in the adult patient population The main search key words were: "perioperative care," "sleep apnea," "obstructive sleep apnea," "perioperative risk," and "perioperative care" The databases Medline, Embase, Biological Abstract, Science Citation Index, and Healthstar were searched for relevant English language articles from 1966 to March 2007 Results The literature supports an increased perioperative risk in OSA patients The American Society of Anesthesiologists guidelines support the routine screening for OSA during preoperative assessment, and methods of OSA screening are discussed in this review This review suggests a number of perioperative management strategies to reduce surgical risk in patients with OSA However, apart from the consensus-based American Society of Anesthesiologists guidelines, it is important to note that evidence-based recommendations are lacking in the literature Conclusions This review suggests ways to screen for OSA in the preoperative setting and proposes perioperative management strategies The ultimate goal is to reduce the perioperative risk of OSA patients but, to realize that goal, research will be needed to determine whether screening for OSA and/or adapting specific perioperative management approaches translates into a lessening of adverse events in surgical patients with undiagnosed OSA

http://stopbang.ca/publication/pdf/pub8.pdf

A systemic review of obstructive sleep apnea and its implications for anesthesiologists.

A processor-based system for analyzing physiologic data and medical care is provided wherein the patient data is analyzed to construct images that are representative of a patient's condition. The processor provides a self-modulating analysis, which is responsive to the occurrence of additional data items to increase the information contained in the images. Identifications of modes of physiologic failure by the analysis of the generated images provides for earlier recognition and intervention and improved protocolization of testing and treatment.

Patient safety processor

A system and method for organization and analysis of complex and dynamically interactive time series is disclosed. One example comprises a processor based system for relational analysis of physiologic signals for providing early recognition of catastrophic and pathologic events such as pathophysiologic divergence. The processor is programmed to identify pathophysiologic divergence of at least one of first and second physiologic parameters in relationship to the other and to output an indication of the divergence. An object-based method of iterative relational processing waveform fragments in the time domain is described wherein each more complex waveform object inherits the characteristics of the waveform objects from which it is derived. The first physiologic parameter can be the amplitude and frequency of the variation in chest wall impedance or nasal pressure and the second parameter can be a measure or indication of the arterial oxygen saturation.

Microprocessor system for the analysis of physiologic and financial datasets

PRACTICE guidelines are systematically developed recommendations that assist the practitioner and patient in making decisions about health care. These recommendations may be adopted, modified, or rejected according to clinical needs and constraints, and are not intended to replace local institutional policies. In addition, practice guidelines developed by the American Society of Anesthesiologists (ASA) are not intended as standards or absolute requirements, and their use cannot guarantee any specific outcome. Practice guidelines are subject to revision as warranted by the evolution of medical knowledge, technology, and practice. They provide basic recommendations that are supported by a synthesis and analysis of the current literature, expert and practitioner opinion, open forum commentary, and clinical feasibility data. This document updates the “Practice Guidelines for the Prevention, Detection and Management of Respiratory Depression Associated with Neuraxial Opioid Administration” adopted by ASA in 2007, and includes new survey data and recommendations pertaining to monitoring for respiratory depression. Methodology

Practice guidelines for the prevention, detection, and management of respiratory depression associated with neuraxial opioid administration.

Current prominent textbooks on anesthesiology mention sleep apnea syndrome (SAS) only briefly. However, three patients in Illinois (two at one hospital) had sudden postoperative arrests associated with epidural opioids and sleep apnea. We therefore reevaluated the literature, which suggests that epidural opioids are the therapy of choice for patients with sleep apnea (1). Of the 15 patients with SAS reported in the literature, 10 had severe respiratory problems due to postoperative analgesia. Only one report was associated with epidural analgesia, to which we now add three. Based on the experiences we now describe (Case Reports l-3) and review of the literature (Case Reports 4-18), we believe that SAS patients are at particularly high risk of postoperative respiratory depression from any mode of analgesic therapy. Our theory is based on a review of a series of cases and not on mathematical estimates of relative risk. Because of our conclusion, we suggest guidelines for the anesthetic management of such patients.

Ostermeier Am

Papers

Three sudden postoperative respiratory arrests associated with epidural opioids in patients with sleep apnea.