Crispiana Cozowicz

Society of Anesthesia and Sleep Medicine Guidelines on Preoperative Screening and Assessment of Adult Patients with Obstructive Sleep Apnea

The purpose of the Society of Anesthesia and Sleep Medicine guideline on preoperative screening and assessment of adult patients with obstructive sleep apnea (OSA) is to present recommendations based on the available clinical evidence on the topic where possible. As very few well-performed randomized studies in this field of perioperative care are available, most of the recommendations were developed by experts in the field through consensus processes involving utilization of evidence grading to indicate the level of evidence upon which recommendations were based. This guideline may not be appropriate for all clinical situations and all patients. The decision whether to follow these recommendations must be made by a responsible physician on an individual basis. Protocols should be developed by individual institutions taking into account the patients’ conditions, extent of interventions and available resources. This practice guideline is not intended to define standards of care or represent absolute requirements for patient care. The adherence to these guidelines cannot in any way guarantee successful outcomes and is rather meant to help individuals and institutions formulate plans to better deal with the challenges posed by perioperative patients with OSA. These recommendations reflect the current state of knowledge and its interpretation by a group of experts in the field at the time of publication. While these guidelines will be periodically updated, new information that becomes available between updates should be taken into account. Deviations in practice from guidelines may be justifiable and such deviations should not be interpreted as a basis for claims of negligence.

The impact of peripheral nerve blocks on perioperative outcome in hip and knee arthroplasty-a population-based study.

Abstract The role of anesthesia techniques on perioperative outcomes on a population level has recently gained widespread interest. Although mainly neuraxial vs general anesthesia has been addressed, population-level data on the impact of peripheral nerve blocks (PNBs) are still lacking. Therefore, we investigated the association between PNB use and outcomes using retrospective data on 1,062,152 recipients of hip and knee arthroplasties (total hip arthroplasty [THA]/total knee arthroplasty [TKA]) from the national Premier Perspective database (2006-2013). Multilevel multivariable logistic regression models measured associations between PNB use and outcomes. Complications included cardiac, pulmonary, gastrointestinal and renal complications, cerebrovascular events, infections, wound complications, thromboembolic complications, inpatient falls, and mortality. Resource utilization variables included blood transfusions, intensive care unit admissions, opioid consumption, cost, and length of stay. Overall, 12.5% of patients received a PNB, with an increase over time particularly among TKAs. Peripheral nerve block use was associated with lower odds for most adverse outcomes mainly among patients with THA. Notable beneficial effects were seen for wound complications (odds ratio 0.60 [95% confidence interval, 0.49-0.74]) among THA recipients and pulmonary complications (odds ratio 0.83 [95% confidence interval, 0.72-0.94]) in patients with TKA. Peripheral nerve block use was significantly (P < 0.0001) associated with a −16.2% and −12.7% reduction in opioid consumption for patients with THA and TKA, respectively. In conclusion, our results indicate that PNBs might be associated with superior perioperative population-level outcomes. In light of the inability to establish a causal relationship and the presence of residual confounding, we strongly advocate for further prospective investigation, ideally in multicenter, randomized trials, to establish the potential impact of PNBs on outcomes on a population level.

Trends in the Use of Regional Anesthesia: Neuraxial and Peripheral Nerve Blocks.

Background A growing body of evidence indicates that the use of regional anesthesia offers advantages over general anesthesia, not only in terms of reducing complications but also regarding resource utilization and patient satisfaction. Because of the paucity of data on the nationwide adoption of regional anesthesia techniques, we aimed to elucidate trends in the use of neuraxial anesthesia (NA) and peripheral nerve blocks (PNBs) in orthopedic surgeries. Methods We extracted data from N = 959,257 (Premier Perspective database; 2006–2013) total hip and knee arthroplasties (THA, TKA) and assessed NA/PNB use by a 2-year period, stratified by demographics and hospital factors. Cochran-Armitage trend tests assessed significance of trends. Results Comparing 2006–2007 with 2012–2013, NA utilization decreased slightly from 21.7% to 19.7% for THA patients; this was 24.7% to 21.3% for TKA patients (with the main drop between 2012 and 2013). Conversely, PNB utilization increased from 6.5% to 8.7% for THA patients and 10.3% to 20.4% for TKA patients (all P < 0.001). These general trends did not change when stratified by patient demographics, whereas stratification by hospital factors did show differences: the highest NA utilization was seen in rural, nonteaching, and small hospitals, whereas the highest PNB utilization was seen in large and teaching hospitals. Conclusions Our findings provide important insight into the dynamics of the adoption of regional anesthetic techniques. Whereas PNB utilization is significantly increasing, overall, NA and PNBs are performed in the minority of cases. With accumulating evidence in favor of regional anesthesia, promoting the use of NA and a further increase in PNB utilization could have far-reaching medical and economic implications.

Epidemiology, trends, and disparities in regional anaesthesia for orthopaedic surgery

Recent studies have linked the use of regional anaesthesia to improved outcomes. Epidemiological research on utilization, trends, and disparities in this field is sparse; however, large nationally representative database constructs containing anaesthesia-related data, demographic information, and multiyear files are now available. Together with advances in research methodology and technology, these databases provide the foundation for epidemiological research in anaesthesia. We present an overview of selected studies that provide epidemiological data and describe current anaesthetic practice, trends, and disparities in orthopaedic surgery in particular. This literature suggests that that even among orthopaedic surgical procedures, which are highly amenable to regional anaesthetic techniques, neuraxial anaesthetics and peripheral nerve blocks are used in only a minority of procedures. Trend analyses show that peripheral nerve blocks are gaining in popularity, whereas use of neuraxial anaesthetics is remaining relatively unchanged or even declining over time. Finally, significant disparities and variability in anaesthetic care seem to exist based on demographic and health-care-related factors. With anaesthesia playing an increasingly important part in population-based health-care delivery and evidence indicating improved outcome with use of regional anaesthesia, more research in this area is needed. Furthermore, prevalent disparities and variabilities in anaesthesia practice need to be specified further and addressed in the future.

Opioid prescription levels and postoperative outcomes in orthopedic surgery

Abstract Given the basic need for opioids in the perioperative setting, we investigated associations between opioid prescription levels and postoperative outcomes using population-based data of orthopedic surgery patients. We hypothesized that increased opioid amounts would be associated with higher risk for postoperative complications. Data were extracted from the national Premier Perspective database (2006-2013); N = 1,035,578 lower joint arthroplasties and N = 220,953 spine fusions. Multilevel multivariable logistic regression models measured associations between opioid dose prescription and postoperative outcomes, studied by quartile of dispensed opioid dose. Compared to the lowest quartile of opioid dosing, high opioid prescription was associated with significantly increased odds for deep venous thrombosis and postoperative infections by approx. 50%, while odds were increased by 23% for urinary and more than 15% for gastrointestinal and respiratory complications (P < 0.001 respectively). Furthermore, higher opioid prescription was associated with a significant increase in length of stay (LOS) and cost by 12% and 6%, P < 0.001 respectively. Cerebrovascular complications risk was decreased by 25% with higher opioid dose (P = 0.004), while odds for myocardial infarction remained unaltered. In spine cases, opioid prescription was generally higher, with stronger effects observed for increase in LOS and cost as well as gastrointestinal and urinary complications. Other outcomes were less pronounced, possibly because of smaller sample size. Overall, higher opioid prescription was associated with an increase in most postoperative complications with the strongest effect observed in thromboembolic, infectious and gastrointestinal complications, cost, and LOS. Increase in complication risk occurred stepwise, suggesting a dose–response gradient.

Suboptimal Diagnostic Accuracy of Obstructive Sleep Apnea in One Database Does Not Invalidate Previous Observational Studies.

<zdoi;10.1097/ALN.0000000000001037> i; . . Anesthesiology, V 124 • No 5 1192 May 2016 To the Editor: We read with interest the article published by McIsaac et al.1 entitled “Identifying Obstructive Sleep Apnea in Administrative Data: A Study of Diagnostic Accuracy.” The authors utilized data collected by a Canadian academic health sciences network within a universal health insurance plan to study the validity of using diagnosis codes to reliably identify patients with obstructive sleep apnea (OSA) within administrative databases. The presence of any registered diagnostic code, procedure, or therapeutic intervention consistent with the presence of sleep apnea within 2 yr before surgery was used as a benchmark. The authors should be commended for their thoughtful undertaking and their contribution toward improving methodology in the field of population-based sleep apnea research. Moreover, the presented findings are convincing; insofar as various diagnosis and billing codes are not reliable in identifying patients with OSA. However, their interpretation as it extends to the value of database studies that have used these codes to determine OSA cohorts may not be valid. First and foremost, the analysis uses specific data to test the authors’ hypothesis, which located in Canada may be substantially different than those including information from US hospitals utilized in the majority of OSA observational studies published to date.2,3 Indeed, next to such important differences such as a single-payer system versus a multipayer system, billing and coding practices have also been shown to be influenced by type of hospital, most importantly among for-profit versus non-for-profit hospitals.4 The difference in International Classification of Diseases, Ninth Revision (ICD9) validity between datasets is also demonstrated in the results presented by authors as they show varying sensitivities and specificities for ICD-9 code 780.5 (“unspecified sleep apnea”) in the Ontario Health Insurance Plan versus the Discharge Abstract Database. Thus, the results presented in the study by McIsaac et al. may not be applicable to other databases, and each data source would require separate validation studies to determine its ability to reliably identify those with OSA. Although it is likely that because of the deficiencies of current coding systems to identify OSA patients, only a fraction of those affected are detected; the biggest effect of this deficiency would be on the determination of the true prevalence of the problem. However, outcome analyses utilizing a cohort of OSA patients (representing all such patients or not) should be less affected by this problem, thus rendering results establishing OSA as a perioperative risk factor for adverse outcomes valid. The authors’ statement that “researchers and knowledge consumers should approach such studies cautiously” is put into perspective by their finding that those patients labeled as “true positives” for OSA appeared to have the highest disease burden putting them at highest risks for adverse perioperative outcomes. However, patients labeled as having OSA in observational studies (using ICD-9 codes) will be a mixture of true and false OSA diagnoses. Therefore, we would expect this misclassification to bias the results of an observational study to the null, as the authors rightfully point out. Therefore, it is very well possible that any association found in observational studies will be an underestimation of the true effects. This would not only mean that the findings reported by McIsaac et al. do not necessarily invalidate previous observational studies in respect to OSA and perioperative outcomes but also mean that their effects may be even larger than suggested. Finally, the authors extracted their reference standard from a cohort of patients who actually underwent a polysomnogram based on unspecified criteria and met diagnostic criteria based on the apnea hypopnea index. Although this makes sense as it is vital in OSA ascertainment, the authors fail to mention and discuss the limitation of undiagnosed OSA, a more crucial and overarching issue as it has been demonstrated that a significant part of surgical OSA patients is missed by surgeons and anesthesiologists.5 Next to the study by McIsaac et al., this limitation also affects all other (observational) studies in which OSA is diagnosed based on a previous decision to perform a polysomnogram. This limitation is also expected to bias results of previous studies to the null and further highlights the need for reliable data, e.g., in the form of a registry. In conclusion, although the study by McIsaac et al. points toward considerable limitations associated with the use of diagnosis codes to identify OSA patients in a Canadian universal health insurance database, these findings neither negate results from previous database studies identifying OSA as a risk factor for adverse outcomes nor can they be extrapolated to other datasets without further testing. We, therefore, suggest that the more important implications of the study by McIsaac et al. are the call for more validation studies and the generation of more reliable data such as a national registry.

Association of Multimodal Pain Management Strategies with Perioperative Outcomes and Resource UtilizationA Population-based Study

Background: Multimodal analgesia is increasingly considered routine practice in joint arthroplasties, but supportive large-scale data are scarce. The authors aimed to determine how the number and type of analgesic modes is associated with reduced opioid prescription, complications, and resource utilization. Methods: Total hip/knee arthroplasties (N = 512,393 and N = 1,028,069, respectively) from the Premier Perspective database (2006 to 2016) were included. Analgesic modes considered were opioids, peripheral nerve blocks, acetaminophen, steroids, gabapentin/pregabalin, nonsteroidal antiinflammatory drugs, cyclooxygenase-2 inhibitors, or ketamine. Groups were categorized into “opioids only” and 1, 2, or more than 2 additional modes. Multilevel models measured associations between multimodal analgesia and opioid prescription, cost/length of hospitalization, and opioid-related adverse effects. Odds ratios or percent change and 95% CIs are reported. Results: Overall, 85.6% (N = 1,318,165) of patients received multimodal analgesia. In multivariable models, additions of analgesic modes were associated with stepwise positive effects: total hip arthroplasty patients receiving more than 2 modes (compared to “opioids only”) experienced 19% fewer respiratory (odds ratio, 0.81; 95% CI, 0.70 to 0.94; unadjusted 1.0% [N = 1,513] vs. 2.0% [N = 1,546]), 26% fewer gastrointestinal (odds ratio, 0.74; 95% CI, 0.65 to 0.84; unadjusted 1.5% [N = 2,234] vs. 2.5% [N = 1,984]) complications, up to a –18.5% decrease in opioid prescription (95% CI, –19.7% to –17.2%; 205 vs. 300 overall median oral morphine equivalents), and a –12.1% decrease (95% CI, –12.8% to –11.5%; 2 vs. 3 median days) in length of stay (all P < 0.05). Total knee arthroplasty analyses showed similar patterns. Nonsteroidal antiinflammatory drugs and cyclooxygenase-2 inhibitors seemed to be the most effective modalities used. Conclusions: While the optimal multimodal regimen is still not known, the authors’ findings encourage the combined use of multiple modalities in perioperative analgesic protocols.

Association of opioid prescription and perioperative complications in obstructive sleep apnea patients undergoing total joint arthroplasties

PurposeObstructive sleep apnea (OSA) has been linked to higher rates of perioperative complications. Practice guidelines recommend minimizing opioids in this cohort to reduce complications. However, a paucity of evidence exists relating different levels of opioid prescription to perioperative complications. Our aim was to investigate if different levels of opioid prescription are related to perioperative complication risk in patients with OSA.MethodsA total of 107,610 OSA patients undergoing total knee or hip arthroplasty between 2006 and 2013 were identified in a nationwide database and divided into subgroups according to the amount of opioids prescribed. We then compared those subgroups for odds of perioperative complications using multilevel multivariable logistic regression models.ResultsOSA patients with higher levels of opioid prescription had increased odds for gastrointestinal complications (OR 1.90, 95% CI 1.47–2.46), prolonged length of stay (OR 1.64, 95% CI 1.57–1.72), and increased cost of care (OR 1.48, 95% CI 1.40–1.57). However, we found lower odds for pulmonary complications (OR 0.85, 95% CI 0.74–0.96) for the high-prescription group.ConclusionsHigher levels of opioid prescription were associated with higher odds for gastrointestinal complications and adverse effects on cost and length of stay but lower odds for pulmonary complications in OSA patients undergoing joint arthroplasties. The latter finding is unlikely causal but may represent more preventive measures and early interventions among those patients. Attempts to reduce opioid prescription should be undertaken to improve quality and safety of care in this challenging cohort in the perioperative setting.

Trends in Perioperative Practice and Resource Utilization in Patients With Obstructive Sleep Apnea Undergoing Joint Arthroplasty.

BACKGROUND: Emerging evidence associating obstructive sleep apnea (OSA) with adverse perioperative outcomes has recently heightened the level of awareness among perioperative physicians. In particular, estimates projecting the high prevalence of this condition in the surgical population highlight the necessity of the development and adherence to “best clinical practices.” In this context, a number of expert panels have generated recommendations in an effort to provide guidance for perioperative decision-making. However, given the paucity of insights into the status of the implementation of recommended practices on a national level, we sought to investigate current utilization, trends, and the penetration of OSA care-related interventions in the perioperative management of patients undergoing lower joint arthroplasties. METHODS: In this population-based analysis, we identified 1,107,438 (Premier Perspective database; 2006–2013) cases of total hip and knee arthroplasties and investigated utilization and temporal trends in the perioperative use of regional anesthetic techniques, blood oxygen saturation monitoring (oximetry), supplemental oxygen administration, positive airway pressure therapy, advanced monitoring environments, and opioid prescription among patients with and without OSA. RESULTS: The utilization of regional anesthetic techniques did not differ by OSA status and overall <25% and 15% received neuraxial anesthesia and peripheral nerve blocks, respectively. Trend analysis showed a significant increase in peripheral nerve block use by >50% and a concurrent decrease in opioid prescription. Interestingly, while the absolute number of patients with OSA receiving perioperative oximetry, supplemental oxygen, and positive airway pressure therapy significantly increased over time, the proportional use significantly decreased by approximately 28%, 36%, and 14%, respectively. A shift from utilization of intensive care to telemetry and stepdown units was seen. CONCLUSIONS: On a population-based level, the implementation of OSA-targeted interventions seems to be limited with some of the current trends virtually in contrast to practice guidelines. Reasons for these findings need to be further elucidated, but observations of a dramatic increase in absolute utilization with a proportional decrease may suggest possible resource constraints as a contributor.

Is obstructive sleep apnea associated with difficult airway? Evidence from a systematic review and meta-analysis of prospective and retrospective cohort studies

Background Difficult airway management and obstructive sleep apnea may contribute to increased risk of perioperative morbidity and mortality. The objective of this systematic review and meta-analysis (SRMA) is to evaluate the evidence of a difficult airway being associated with obstructive sleep apnea (OSA) patients undergoing surgery. Methods The standard databases were searched from 1946 to April 2017 to identify the eligible articles. The studies which included adult surgical patients with either suspected or diagnosed obstructive sleep apnea must report at least one difficult airway event [either difficult intubation (DI), difficult mask ventilation (DMV), failed supraglottic airway insertion or difficult surgical airway] in sleep apnea and non-sleep apnea patients were included. Results Overall, DI was 3.46-fold higher in the sleep apnea vs non-sleep apnea patients (OSA vs. non-OSA: 13.5% vs 2.5%; OR 3.46; 95% CI: 2.32–5.16, p <0.00001). DMV was 3.39-fold higher in the sleep apnea vs non-sleep apnea patients (OSA vs. non-OSA: 4.4% vs 1.1%; OR 3.39; 95% CI: 2.74–4.18, p <0.00001). Combined DI and DMV was 4.12-fold higher in the OSA vs. non-OSA patients (OSA vs. non-OSA: 1.1% vs 0.3%; OR 4.12; 95% CI: 2.93–5.79, p <0.00001). There was no significant difference in the supraglottic airway failure rates in the sleep apnea vs non-sleep apnea patients (OR: 1.34; 95% CI: 0.70–2.59; p = 0.38). Meta-regression to adjust for various subgroups and baseline confounding factors did not impact the final inference of our results. Conclusion This SRMA found that patients with obstructive sleep apnea had a three to four-fold higher risk of difficult intubation or mask ventilation or both, when compared to non-sleep apnea patients.