Potentially life-threatening sleep apnea is unrecognized without aggressive evaluation

Evaluating the effect of preoperative interventions on sleep health in the perioperative period: a systematic review

Surgery and general anaesthesia have deleterious effects on sleep and disrupted perioperative sleep health is a risk factor for poor surgical outcomes. The objective of this systematic review was to summarise preoperative interventions that report sleep outcomes. Studies that delivered an intervention initiated >24 h prior to surgery among an adult sample without a diagnosed sleep disorder were included. Studies were excluded if they were preclinical or were not published in English. MEDLINE, MEDLINE ePubs Ahead of Print and In-process Citations, Embase, Cochrane Central Register of Controlled Trials, APA PsycINFO, CINAHL, and the Web of Science were searched on February 2, 2023. This review was reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses and was registered with the International Prospective Register of Systematic Reviews (identifier: CRD42021260578). Risk of bias was assessed using the Cochrane Risk-of Bias 2 tool for randomised trials and the Risk Of Bias In Non-randomised Studies - of Interventions for non-randomised trials. Certainty of findings were assessed using the Grading of Recommendations, Assessment, Development and Evaluation framework. The searching yielded 10,938 total citations, and after screening resulted in 28 randomised and 19 non-randomised trials (47 total) with 4937 participants. Sleep was a primary outcome in 16 trials; a sleep outcome was significantly improved relative to comparator in 23 trials. This review demonstrates that preoperative sleep is modifiable via a variety of interventions, including pharmacological, non-pharmacological, and nursing interventions delivered preoperatively or perioperatively. Our results should be considered with caution due to an overall intermediate to high risk of bias in the included trials, and low to very low certainty of evidence. This review supports the modifiability of sleep health among surgical patients and provides the groundwork for preoperative sleep optimisation research.

Combined application of pharyngeal volume and minimal cross-sectional area may be helpful in screening persons suspected of obstructive sleep apnea (OSA)

BACKGROUND

Obstructive sleep apnea (OSA) is a common disease that seriously affects human health and daily life. However, the gold standard for its diagnosis, polysomnography (PSG), is expensive resulting in inadequate diagnosis of this disease in primary clinics. Therefore, a simple and rapid method for initial screening for OSA is needed. Acoustic pharyngometry (APh) is an FDA-approved noninvasive method that is gradually being applied to screening for OSA.

MATERIALS AND METHODS

In this study, we applied analysis with receiver operating characteristic (ROC) curves to explore how APh may play a greater role in the screening of subjects with suspected OSA. Patients admitted into the departments of otolaryngology at our hospital from March 2017 to May 2019 were recruited into the study. All subjects underwent PSG monitor and were separated into two groups according to the apnea-hypopnea index (AHI) from the PSG results: OSA group (AHI ≥ 5) and control group (AHI < 5). APh measurements and other indicators of the subjects, including age, height, and weight; Epworth Sleepiness Scale (ESS) score; and the pharynx examination, including the degree of tonsil enlargement and tongue hypertrophy, were also be recorded.

RESULTS

The t-test results showed that almost all indicators except age and height have significant differences between the OSA group and control group. Subjects with OSA had greater weight, BMI, ESS, higher degree of tonsil enlargement, and tongue hypertrophy, while they had smaller minimal cross-sectional area (mCSA) and pharyngeal volume than the subjects in control group. The correlation analysis revealed that pharyngeal volume and mCSA were two helpful indicators to screen for OSA. Furthermore, we established the ROC curve and calculated the combining predictors (combining predictors = pharyngeal volume + mCSA * (- 2.347)/(- 0.225)). The area under the ROC curve (AUC) of combining predictors was 0.917 (95% CI 0.842-0.991, P < 0.001), which was higher than combinations of other two independent indicators. The cutoff point of combining predictors was found to be 59.84 (AUC = 0.917, sensitivity = 0.80, 1-specificity = 0.06, P < 0.001).

CONCLUSIONS

These findings suggest that APh is a simple, rapid, and economical detection method which may be useful in screening for OSA, especially in communities and primary clinics where PSG cannot be performed.

No Uniformity in the References of Clinical Practice Guidelines for Bariatric Surgery: a Review of 3 Similar Guidelines Published in 2020

In 2020, updated versions of the clinical practice guidelines of the European Association for Endoscopic Surgery, the Canadian Adult Obesity Clinical Practice Guidelines and the Dutch Federation for Medical Specialist clinical practice guidelines on bariatric surgery were published. We systematically reviewed and compared them on recommendations and references. Although the authors would have had access to the same literature, only 5 out of 655 unique references were used by all 3 guidelines and just 49 references by any combination of 2 guidelines. These findings attest to the subjectivity involved in clinical practice guidelines development and could be the cause for the observed differences in recommendations. International cooperation in guideline development might be a conceivable solution.

Metabolic surgery in treatment of obese Japanese patients with type 2 diabetes: a joint consensus statement from the Japanese Society for Treatment of Obesity, the Japan Diabetes Society, and the Japan Society for the Study of Obesity

Bariatric surgery has been shown to have a variety of metabolically beneficial effects for patients with type 2 diabetes (T2D), and is now also called metabolic surgery. At the 2nd Diabetes Surgery Summit held in 2015 in London, the indication for bariatric and metabolic surgery was included in the “algorithm for patients with type T2D”. With this background, the Japanese Society for Treatment of Obesity (JSTO), the Japan Diabetes Society (JDS) and the Japan Society for the Study of Obesity (JASSO) have formed a joint committee to develop a consensus statement regarding bariatric and metabolic surgery for the treatment of Japanese patients with T2D. Eventually, the consensus statement was announced at the joint meeting of the 38th Annual Meeting of JSTO and the 41st Annual Meeting of JASSO convened in Toyama on March 21, 2021. In preparing the consensus statement, we used Japanese data as much as possible as scientific evidence to consider the indication criteria, and set two types of recommendation grades, “recommendation” and “consideration”, for items for which recommendations are possible. We hope that this statement will be helpful in providing evidence-based high-quality care through bariatric and metabolic surgery for the treatment of obese Japanese patients with T2D.

Risk of work-related injury in workers with obstructive sleep apnea: A systematic review and meta-analysis

The objective of this study is to elucidate the relationship between obstructive sleep apnea (OSA) and the risk of work-related injuries (WRIs), synthesize the latest clinical evidence and conduct a systematic review and meta-analysis adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA 2020). Observational studies published before April 2020 in PubMed, Cochrane library, PsycINFO, Scopus, Google Scholar and Web of Science were included. Random-effects Mantel-Haenszel meta-analysis was performed. A total of 15 studies with 21,507 participants were included. Prespecified subgroup analyses based on study design and the characteristics of the enrollees were conducted. Overall, workers with OSA had 1.64-fold increased odds of being involved in WRIs compared to their counterparts (OR = 1.64, 95% CI = 1.24-2.16, p = 0.0005). In addition to the professional drivers that have been studied in the past, such a trend also existed in the general working population (OR = 1.68, 95% CI = 1.14-2.49, p = 0.01). We also found that workers with excessive daytime sleepiness (Epworth Sleepiness Scale score >10) had a 1.68-fold increased risk of WRIs compared to those with lower ESS scores (OR = 1.68, 95% CI = 1.22-2.30, p = 0.002). This study verified that OSA workers had a higher risk of WRIs, and such correlations do not show obvious differences in subgroups with different sample sizes, OSA diagnosis methods, job types or definitions of WRI. Based on the association between OSA and WRIs identified in our study, further studies investigating the protective effects of early identification and management of OSA on WRIs are warranted.

The prevalence and impact of pre-existing sleep disorder diagnoses and objective sleep parameters in patients hospitalized for COVID-19

STUDY OBJECTIVES

Obstructive sleep apnea and other sleep disorders overlap with comorbidities associated with poor outcomes related to severe acute respiratory syndrome coronavirus 2 infection. However, the prevalence of obstructive sleep apnea among patients hospitalized for COVID-19 and relationship to outcomes is poorly characterized, and the relevance of other sleep disorders remains unknown. The objective of this study was to identify the prevalence of pre-existing sleep disorders and association with outcomes related to severe COVID-19 illness.

METHODS

Patients with severe acute respiratory syndrome coronavirus 2 infection admitted to the University of Michigan Hospital System were included. Electronic medical records were queried for sleep disorders diagnostic codes. Data were extracted from polysomnography and home sleep testing in a subgroup with previous diagnostic testing at our center. Logistic regression was used to examine the association of sleep disorders with mechanical ventilation requirement, treatment with vasopressors, and death and Cox proportional hazards regression for time to discharge.

RESULTS

Among n = 572 adult patients hospitalized for COVID-19, 113 (19.8%) patients had obstructive sleep apnea, 4 patients had central sleep apnea (0.7%), 5 had hypoventilation (0.9%), 63 had insomnia (11.0%), and 22 had restless legs syndrome or periodic limb movements disorder (3.9%). After adjusting for age, sex, body mass index, and race, no significant relationship was apparent between sleep disorders diagnoses or indices of sleep-disordered breathing severity and outcomes.

CONCLUSIONS

This is the first study to determine the prevalence of obstructive sleep apnea and other sleep disorders in a well-characterized cohort of patients hospitalized for COVID-19. Once hospitalized, a significant contribution of sleep disorders to outcomes was not identified. Therefore, future evaluations should focus on earlier outcomes, such as infection or clinical manifestations after exposure to severe acute respiratory syndrome coronavirus 2.

Obstructive sleep apnea in obese adolescents referred for bariatric surgery: association with metabolic and cardiovascular variables

BACKGROUND

obstructive sleep apnea syndrome (OSA) is a well-described disease entity in adults, with a higher prevalence in severely obese individuals, while at the same time associated with several comorbidities independently of BMI. Literature regarding OSA in severely obese adolescents is qualitatively and quantitatively limited, possibly resulting in suboptimal diagnosis and treatment.

METHODS

polysomnographic, demographic, anthropometric, and comorbidity-related data were prospectively collected in 56 adolescents with morbid obesity refractory to conservative treatment who presented for surgical therapy. Differences between adolescents with no/mild (apnea-hypopnea index (AHI) 0-4.9) and moderate/severe OSA (AHI ≥ 5.0) were evaluated using independent-samples t, chi-square or Fisher's exact tests. Multivariable linear regression analysis was performed to evaluate the association of several variables with AHI, corrected for BMI z-score.

RESULTS

of the 53 included subjects, 48 (90.6%) showed some degree of sleep disordered breathing and 20 (37.7%) had moderate/severe OSA. Patients with moderate/severe OSA had on average a higher neck circumference (42.4 versus 40.1 cm, p = 0.008), higher BMI z-score (3.7 versus 3.4, p = 0.003), higher plasma triglyceride level (2.2 versus 1.5 mmol/L, p = 0.012), and lower IGF (29.6 versus 40.2 mmol/L, p = 0.010) than those with no/mild OSA. BMI z-score and plasma triglyceride levels were independently related to AHI.

CONCLUSIONS

OSA is highly prevalent amongst morbidly obese adolescents and is strongly associated with BMI z-score. Elevated plasma triglyceride levels are associated with AHI, independent of BMI z-score.

Prevalence of obstructive sleep apnea in an Asian bariatric population: an underdiagnosed dilemma

BACKGROUND

Obesity is a growing health problem that has become a global epidemic. Serial population studies have shown the same in Malaysia, where the prevalence of obesity increased rapidly in the last decade. Currently, bariatric surgery is the most effective treatment in patients with morbid obesity. Obstructive sleep apnea (OSA) is the most common type of sleep-related breathing disorder seen in obesity.

OBJECTIVES

We aim to ascertain the prevalence and severity of OSA in Asian patients who underwent bariatric surgery and were seen in our center.

SETTING

The study was conducted in our university hospital.

METHODS

Study approval was obtained from our institutional review board for a retrospective chart review. A total of 226 patients were included in this review. OSA was noted as absent or present and graded from mild to severe. The patient population was stratified by body mass index according to the World Health Organization guidelines for Asian population.

RESULTS

The overall sample prevalence of OSA was 80.5%. Of these, 24.3% had mild OSA, 23.9% had moderate OSA, and 32.3% had severe OSA. Only 17.3% have been diagnosed with OSA before bariatric workup. Among men, the prevalence of OSA was 93.7% and 75.5% among women.

CONCLUSION

Based on these findings, Asian patients undergoing bariatric workup should be considered for routine polysomnography to enable treatment of OSA.

A new sensitive and accurate model to predict moderate to severe obstructive sleep apnea in patients with obesity

Obstructive sleep apnea (OSA) has a high prevalence in patients with obesity. Only patients with clinical symptoms of OSA are admitted to polysomnography; however, many patients with OSA are asymptomatic. We aimed to create and validate a population-based risk score that predicts the severity of OSA in patients with obesity.We here report the cross-sectional analysis at baseline of an ongoing study investigating the long-term effect of bariatric surgery on OSA. One-hundred sixty-one patients of the Obesity Center of the Catholic University Hospital in Rome, Italy were included in the study. The patients underwent overnight cardiorespiratory monitoring, blood chemistry analyses, hepatic ultrasound, and anthropometric measurements. The patients were divided into 2 groups according OSA severity assessed by the apnea-hypopnea index (AHI): AHI < 15 = no or mild and AHI ≥ 15 moderate to severe OSA. A statistical prediction model was created and validated. C statistics was used to evaluate the discrimination performance of the model.The prevalence of OSA was 96.3% with 74.5% of the subjects having moderate/severe OSA. Sex, body mass index, diabetes, and age were included in the final prediction model that had excellent discrimination ability (C statistics equals to 83%). An OSA risk chart score for clinical use was created.Patients with severe obesity are at a very high risk for moderate or severe OSA in particular if they are men, older, more obese, and/or with type 2 diabetes. The OSA risk chart can be useful for general practitioners and patients as well as for bariatric surgeons to select patients with high risk of moderate to severe OSA for further polysomnography.

A pilot study on the biomechanical assessment of obstructive sleep apnea pre and post bariatric surgery

Obesity is a major risk factor for obstructive sleep apnea patients. In obese patients the severity of this risk can be reduced by bariatric surgery. This pilot study investigates the perioperative effects of bariatric surgery on obstructive sleep apnea and on the physical and biomechanical characteristics of the upper airway. Polysomnography and computer tomography data for 10 morbid obese patients promoted for bariatric surgery were conducted before surgery and at 6 and 12 months postoperatively for assessment of the oropharyngeal anatomy, and subsequent three-dimensional modelling of the airway. Mean values for the apnea/hypopnea index and body mass index significantly reduced after surgery. To combine the effect of changes in the upper airway volume and body mass index, a new volume body mass index is introduced. This index increases with a successful bariatric surgery. Although bariatric surgery leads to an effective weight reduction for all age groups, for obstructive sleep apnea patients it may be effective for middle age, less effective for 50-60 years, and further less effective for patients over the age of 60 years.

BMI 35 kg/m2 does not fit everyone: a modified STOP-Bang questionnaire for sleep apnea screening in the Chinese population

PURPOSE

The STOP-Bang questionnaire is the most widely used to detect surgical patients at high risk of obstructive sleep apnea (OSA). However, the body mass index (BMI) cutoff value in the original STOP-Bang questionnaire is 35 kg/m²; the BMI in the Chinese population is lower than that. We aimed to establish a more appropriate BMI cutoff value in the STOP-Bang questionnaire for Chinese patients.

METHODS

A total of 790 consecutive patients scheduled to undergo surgery at our hospital were included in this prospective study. All patients were asked to complete the STOP-Bang questionnaire and undergo a 7-h overnight polysomnography (PSG). The ability of STOP-Bang questionnaire to detect moderate to severe OSA (AHI ≥ 15 events/h) was assessed.

RESULTS

When the BMI cutoff value was set at 28 kg/m², the questionnaire had the highest Youden index, although no significant differences were found in the sensitivity of the test compared with the original BMI cutoff in total and in male patients. In females, changing the BMI cutoff value from 35 to 28 kg/m² resulted in the sensitivity of the test significantly increasing from 79.2% (74.9-83.5) to 89.3% (84.4-94.1), while the decrease in specificity was minor (from 43.6% [41.2-46.0] to 38.2% [36.1-40.3]), and the Youden index was highest (0.27) at this cutoff value. When the STOP-Bang questionnaire score was 4, the highest Youden index was obtained.

CONCLUSIONS

We recommend using a BMI cutoff value (28 kg/m²), and a STOP-Bang score ≥ 4 allows the anesthetist to identify patients with high risk of OSA.

Preoperatively Screened Obstructive Sleep Apnea Is Associated With Worse Postoperative Outcomes Than Previously Diagnosed Obstructive Sleep Apnea

BACKGROUND

Obstructive sleep apnea (OSA) affects up to 26% of US adults, is often undiagnosed, and increases perioperative morbidity. We hypothesized that patients screened on the day of surgery as moderate/high risk for OSA (S-OSA) present similar perioperative respiratory complications, hospital use, and mortality than patients with previously diagnosed OSA (D-OSA). Second, we hypothesized that both OSA groups have more respiratory complications than No-OSA patients.

METHODS

The electronic medical database from 1 academic and 2 community hospitals was retrospectively queried to identify adults undergoing nonemergent inpatient surgery (January 1, 2012, to December 31, 2014). Based on the day-of-surgery preoperative assessment and STOP-BANG (Snoring, Tiredness, Observed apnea during sleep, high blood Pressure, Body mass index >35, Age >50 years, thick Neck, Gender male) score, they were classified as D-OSA, S-OSA, or No-OSA. Perioperative respiratory events and interventions, hospital use, and mortality were measured. The primary outcome composite (adverse respiratory events [AREs]) included perioperative hypoxemic events and difficult airway management. Hypoxemic event was defined as peripheral saturation of oxygen (SpO2) <90% by continuous pulse oximetry for ≥3 minutes, or if validated and/or manually entered into the medical chart. Hypoxemia was classified as mild (lowest SpO2 86%-89%) or moderate/severe (lowest SpO2 ≤85%). Secondary outcomes included postoperative respiratory interventions, intensive care unit admission, hospital length of stay, and 30-day and 1-year all-cause mortality. Outcomes were compared using linear and logistic regression analyses.

RESULTS

A total of 28,912 patients were assessed: 3432 (11.9%) D-OSA; 1546 (5.3%) S-OSA; and 23,934 (82.8%) No-OSA patients. At least 1 ARE was present in 68.0% of S-OSA; 71.0% of D-OSA; and 52.1% of No-OSA patients (unadjusted P < .001), primarily ≥1 moderate/severe hypoxemic event after discharge from the postanesthesia care unit (PACU; 39.9% in S-OSA; 39.5% in D-OSA; and 27.1% in No-OSA patients). S-OSA patients compared to D-OSA patients presented lower rates of moderate/severe hypoxemia in the PACU but similar intraoperatively and postoperatively, higher difficult mask ventilation rates, and similar difficult intubation reports. After adjusting for demographic, health, and surgical differences and hospital type, the likelihood of ≥1 ARE was not different in S-OSA and D-OSA patients (adjusted odds ratio 0.90 [99% confidence interval, 0.75-1.09]; P = .15). S-OSA patients compared to D-OSA patients had significantly increased postoperative reintubation, mechanical ventilation, direct intensive care unit admission after surgery, hospital length of stay, and 30-day all-cause mortality.

CONCLUSIONS

Patients classified as S-OSA have similar rates of AREs to D-OSA patients, but increased postoperative respiratory interventions, hospital use, and 30-day all-cause mortality. These worse postoperative outcomes in S-OSA patients than D-OSA patients could reflect the lack of awareness and appropriate management of this bedside S-OSA diagnosis after PACU discharge. Multidisciplinary interventions are needed for these high-risk patients.

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

Supplemental Digital Content is available in the text.

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.

Factors predictive of obstructive sleep apnea in patients undergoing pre-operative evaluation for bariatric surgery and referred to a sleep laboratory for polysomnography

Objective:

To identify the main predictive factors for obtaining a diagnosis of obstructive sleep apnea (OSA) in patients awaiting bariatric surgery.

Methods:

Retrospective study of consecutive patients undergoing pre-operative evaluation for bariatric surgery and referred for in-laboratory polysomnography. Eight variables were evaluated: sex, age, neck circumference (NC), BMI, Epworth Sleepiness Scale (ESS) score, snoring, observed apnea, and hypertension. We employed ROC curve analysis to determine the best cut-off value for each variable and multiple linear regression to identify independent predictors of OSA severity.

Results:

We evaluated 1,089 patients, of whom 781 (71.7%) were female. The overall prevalence of OSA-defined as an apnea/hypopnea index (AHI) ≥ 5.0 events/h-was 74.8%. The best cut-off values for NC, BMI, age, and ESS score were 42 cm, 42 kg/m², 37 years, and 10 points, respectively. All eight variables were found to be independent predictors of a diagnosis of OSA in general, and all but one were found to be independent predictors of a diagnosis of moderate/severe OSA (AHI ≥ 15.0 events/h), the exception being hypertension. We devised a 6-item model, designated the NO-OSAS model

(NC, Obesity, Observed apnea, Snoring, Age, and Sex), with a cut-off value of ≥ 3 for identifying high-risk patients. For a diagnosis of moderate/severe OSA, the model showed 70.8% accuracy, 82.8% sensitivity, and 57.9% specificity.

Conclusions:

In our sample of patients awaiting bariatric surgery, there was a high prevalence of OSA. At a cut-off value of ≥ 3, the proposed 6-item model showed good accuracy for a diagnosis of moderate/severe OSA.

CPAP in the Perioperative Setting: Evidence of Support

OSA is a commonly encountered comorbid condition in surgical patients. The risk of cardiopulmonary complications is increased by two to threefold with OSA. Among the different treatment options for OSA, CPAP is an efficacious modality. This review examines the evidence regarding the use of CPAP in the preoperative and postoperative periods in surgical patients with diagnosed and undiagnosed OSA.

Nasopharyngeal chordoma in a patient with a severe form of sleep-disordered breathing: A case report

Nasopharyngeal chordoma is a rare type of malignant neoplasm that originates in the remnants of the notochord, a primitive tissue of embryonic origin preserved outside the axial skeleton. Approximately one-third of chordomas are located in the base of the skull, in the midline of the body. The slow growth rate of the tumor, which gradually fills the nasopharyngeal cavity, contributes to a delayed oncological diagnosis. Among its isolated and non-specific symptoms, the obstruction of the nasopharynx is dominant, thus, sleep-disordered breathing (SDB) may occur. The current study presents the case of a 32-year-old female patient who was incidentally diagnosed with a nasopharyngeal chordoma during a diagnostic examination for SDB. The diagnostic examination was performed as a part of a research program for pathologically obese patients who qualified for bariatric surgery. Following tumor resection, a significant improvement in various polysomnographic parameters occurred, including a decrease in the apnea hypopnea index from 53.5 to 6.4 and an increase in the mean saturation rate from 92.5 to 95%, confirming that an association exists between tumor obstruction of the nasopharynx and SDB. The incidental diagnosis of this rare type of neoplasm drew attention to diagnostic and therapeutic problems associated with nasopharyngeal chordomas. Furthermore, it indicated the necessity for the accurate laryngological examination of patients with SDB.

STOP-Bang and the effect on patient outcome and length of hospital stay when patients are not using continuous positive airway pressure

BACKGROUND

In patients undergoing surgical interventions under general anesthesia, obstructive sleep apnea syndrome (OSA) can cause serious perioperative cardiovascular or respiratory complications leading to fatal consequences, even sudden death. In this study we test the hypothesis that morbidly obese patients diagnosed by a polysomnography test and using continuous positive airway pressure (CPAP) therapy have fewer and less severe perioperative complications and a shorter hospital stay than patients who have a medical history that meets at least three STOP-Bang criteria and are not using CPAP therapy.

METHODS

Postoperative hospital stay and pulmonary complications were analyzed in three groups of morbidly obese patients undergoing bariatric surgery (Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy) between January 2009 and November 2013 (n = 693). Group A comprised 99 patients who were preoperatively diagnosed with OSA based on polysomnography results. These patients used CPAP therapy before and after surgery. Group B consisted of 182 patients who met at least three STOP-Bang criteria but who were not diagnosed with OSA based on polysomnography results. These patients did not use CPAP. Group C, the reference group, comprised 412 patients who scored one to two items on the STOP-Bang.

RESULTS

During the perioperative period, Group B patients had a significantly (p < 0.001) higher cumulative rate of pulmonary complications, worse oxygen saturation, respiratory rates, and increased length of stay in hospital. There was also two cases of sudden death in this group.

CONCLUSION

Based on these results, we conclude that patients meeting at least three STOP-BANG criteria have higher postoperative complications and an increased length of hospital stay than patients using CPAP.

Emerging risk factors and prevention of perioperative pulmonary complications

Modern surgery is faced with the emergence of newer "risk factors" and the challenges associated with identifying and managing these risks in the perioperative period. Obstructive sleep apnea and obesity hypoventilation syndrome pose unique challenges in the perioperative setting. Recent studies have identified some of the specific risks arising from caring for such patients in the surgical setting. While all possible postoperative complications are not yet fully established or understood, the prevention and management of these complications pose even greater challenges. Pulmonary hypertension with its changing epidemiology and novel management strategies is another new disease for the surgeon and the anesthesiologist in the noncardiac surgical setting. Traditionally most such patients were not considered surgical candidates for any required elective surgery. Our review discusses these disease entities which are often undiagnosed before elective noncardiac surgery.

Airway management in the outpatient setting

Most outpatient cosmetic procedures are now performed in surgeons' offices, with patients under local anesthesia and minimal intravenous sedation. Sedation at any level beyond minimal creates the risk of airway obstruction and ventilatory depression, which can result in irreversible brain injury or death within minutes. This article discusses appropriate patient and procedure selection, and outlines the personnel, equipment, and techniques necessary to avoid such outcomes.

Perioperative risk stratification for a patient with severe obstructive sleep apnoea undergoing laparoscopic banding surgery

Despite the increasing prevalence of obstructive sleep apnoea (OSA), there is limited evidence to guide appropriate preoperative investigations, inpatient or outpatient surgery allocation, and the anticipated level of postoperative care. With reference to our institution's perioperative risk stratification, we describe the case of a 46-year-old Caucasian male with a body mass index of 51 kg/m(2) admitted for laparoscopic band insertion. Management based on our guidelines involved a preoperative polysomnography where the patient was confirmed to have severe OSA. His postoperative care was then managed in the high dependency care unit. He was discharged home on day 2 with no further sequelae. We provide evidence that adoption of this model of care can simplify clinical decision making and resource allocation with favourable patient outcomes.

Meta-analysis of the association between obstructive sleep apnoea and postoperative outcome

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.

Optimizing screening of severe obstructive sleep apnea in patients undergoing bariatric surgery

BACKGROUND

Obstructive sleep apnea is common in patients waiting for bariatric surgery (BS). International consensuses have recommended assessment of obstructive sleep apnea in the preoperative evaluation to avoid perioperative complications. Polysomnography is the standard diagnostic method but is expensive and time-consuming. The aim of our study was to detect those patients who merit treatment before BS using a simple predictor model. The study was conducted at 3 university hospitals (Hospital de Bellvitge, Hospital de la Santa Creu i Sant Pau, Hospital Clinic de Barcelona).

METHODS

A prospective cross-sectional study was conducted of 136 consecutive bariatric subjects. The outcome variable was severe obstructive sleep apnea, defined as an apnea-hypoapnea index of ≥30 events/hr by polysomnography. The predictors evaluated were anthropometric and clinical in the first model, with an oxygen desaturation index of ≥3% added to the second model. Predictive models were constructed using multivariate logistic regression analysis. The best model was selected according to the area under the receiver operating characteristic curve.

RESULTS

The first model identified 4 independent factors: age, waist circumference, systolic blood pressure, and witnessed apnea episodes, with a sensitivity of 78%, specificity of 68%, and area under the receiver operating characteristic curve of .83 (95% confidence interval .76-.90, P < .001). The second model identified 2 independent factors (witness apnea episodes, oxygen desaturation index of ≥3%), with a sensitivity of 91%, specificity of 85%, and area under the receiver operating characteristic curve of .94 (95% confidence interval .89-.98, P < .001). The 2-step model predictive values were sensitivity of 90%, specificity of 91%, and accuracy of 90% (95% confidence interval 84-94%). After applying the first model and then the second, 45% of subjects would have been ruled out (15% and 30%, respectively) and 55% would require additional sleep management before BS.

CONCLUSION

The proposed model could be useful for improving the management of complex patients before BS and optimizing limited polysomnography resources.

Obstructive sleep apnea is underrecognized and underdiagnosed in patients undergoing bariatric surgery

The aim of this study was to evaluate prevalence of obstructive sleep apnea among patients undergoing bariatric surgery and the predictive value of various clinical parameters: body mass index (BMI), neck circumference (NC) and the Epworth Sleepiness Scale (ESS). We performed a prospective, multidisciplinary, single-center observational study including all patients on the waiting list for bariatric surgery between June 2009 and June 2010, irrespective of history or clinical findings. Patients visited our ENT outpatient clinic for patient history, ENT and general examination and underwent a full night polysomnography, unless performed previously. As much as 69.9% of the patients fulfilled the criteria for OSA (mean BMI 44.2 ± SD 6.4 kg/m²); 40.4% of the patients met the criteria for severe OSA. The regression models found BMI to be the best clinical predictor, while the ROC curve found the NC to be the most accurate predictor of the presence of OSA. The discrepancy of the results and the poor statistical power suggest that all three clinical parameters are inadequate predictors of OSA. In conclusion, in this large patient series, 69.9% of patients undergoing BS meet the criteria for OSA. More than 40% of these patients have severe OSA. A mere 13.3% of the patients were diagnosed with OSA before being placed on the waiting list for BS. On statistical analysis, increased neck circumference, BMI and the ESS were found to be insufficient predictors of the presence of OSA. Polysomnography is an essential component of the preoperative workup of patients undergoing BS. When OSA is found, specific perioperative measures are indicated.

Perioperative care of patients with obstructive sleep apnea

OPINION STATEMENT

It has been demonstrated that patients undergoing surgical procedures are at increased risk for complications if they have obstructive sleep apnea. It is believed that this increase in risk is related to more difficult intubations, use of ventilatory depressant medications, and perhaps body positioning. Although identifying patients with a preexisting diagnosis of sleep apnea is important so they can be triaged appropriately during the perioperative period, a bigger challenge is trying to identify patients who require a surgical procedure and may have undiagnosed sleep apnea. Hospitals and surgical centers should have policies in place to assist in such identification preoperatively, with a protocol on how to manage such patients perioperatively. Such guidelines exist, but many institutions do not have such protocols in place or fail to ensure that they are consistently followed. The key to the perioperative management is close observation of these high-risk patients. In ambulatory surgery populations, these patients should be observed for an extended period before being discharged to home. In inpatient settings, the observation can be tailored to the patient's postoperative risks based on the type of surgery and the severity of his or her sleep apnea. Patients undergoing bariatric surgery are at particularly high risk. These patients have a very high prevalence of sleep apnea and comorbid conditions. Screening this population for obstructive sleep apnea is mandatory, and a plan for postoperative observation should be in place in all institutions performing such surgery.

Sleep apnea syndrome is significantly underdiagnosed in bariatric surgical patients

BACKGROUND

Devastating morbidity and mortality can result when patients with undiagnosed sleep apnea syndrome (SAS) undergo bariatric surgery. We evaluated the prevalence of SAS and its rate of nondiagnosis in bariatric patients at a university hospital.

METHODS

The demographic, anthropomorphic, and co-morbidity data were collected from 1368 patients evaluated for bariatric surgery. All patients were screened for symptoms of SAS, and symptomatic patients were evaluated with polysomnography.

RESULTS

At the time of this report, 834 patients (61%) had completed the preoperative evaluation. Of these patients, 210 (25%) presented with previously diagnosed SAS. An additional 174 patients (21%) exhibited symptoms of SAS and underwent polysomnography. Most patients tested (127, 73%) had SAS that required treatment, 11 patients (6%) had mild SAS not requiring treatment, and 36 (21%) tested negative for SAS. Thus, symptom screening for SAS had a positive predictive value of 79% for predicting the presence of SAS and 73% for identifying patients who required SAS treatment. The patients with SAS tended to be older and male and have a greater body mass index (P < .05).

CONCLUSION

Overall, SAS that required treatment with an oral appliance was prevalent (40%) in patients who presented for bariatric surgery. However, many of these patients with significant SAS (38%) were previously undiagnosed, despite exhibiting clear symptoms of the disease. Symptom screening appears to be effective in identifying patients who should be evaluated by polysomnography. To avoid the potential perils of undiagnosed SAS during the perioperative period, patients who undergo bariatric surgery should be screened, tested, and treated for this co-morbidity.

Bariatric surgery

BACKGROUND

Bariatric surgery has increased in numbers, but the treatment of morbid obesity in Germany still needs improvement. The new interdisciplinary S3-guideline provides information on the appropriate indications, procedures, techniques, and follow-up care.

METHODS

Systematic review of the literature, classification of the evidence, graded recommendations, and interdisciplinary consensus-building.

RESULTS

Bariatric surgery is a component of the multimodal treatment of obesity, which consists of multidisciplinary evaluation and diagnosis, conservative and surgical treatments, and lifelong follow-up care. The current guideline extends the BMI-based spectrum of indications that was previously proposed (BMI greater than 40 kg/m(2), or greater than 35 kg/m(2)with secondary diseases) by eliminating age limits, as well as most of the contraindications. A prerequisite for surgery is that a structured, conservative weight-loss program has failed or is considered to be futile. Type 2 diabetes is now considered an independent indication under clinical study conditions for patients whose BMI is less than 35 kg/m(2) (metabolic surgery). The standard laparoscopic techniques are gastric banding, gastric bypass, sleeve gastrectomy, and biliopancreatic diversion. The choice of procedure is based on knowledge of the results, long-term effects, complications, and individual circumstances. Structured lifelong follow-up should be provided and should, in particular, prevent metabolic deficiencies.

CONCLUSION

The guideline contains recommendations based on the scientific evidence and on a consensus of experts from multiple disciplines about the indications for bariatric surgery, the choice of procedure, techniques, and follow-up care. It should be broadly implemented to improve patient care in this field.

Anaesthesia for bariatric surgery

Although many smaller studies have addressed anaesthetic care for bariatric surgical patients, comprehensive systematic literature reviews have yet to be compiled, and much evidence includes expert panel opinion. This review summarises study results in bariatric surgical patients regarding pre-anaesthesia evaluation, the perioperative impact of sleep-disordered breathing, airway management at anaesthetic induction and emergence, maintenance of anaesthesia, postoperative pain management, utility of clinical-care pathways and feasibility of outpatient bariatric surgery. The 'ramped' upper-body, reversed Trendelenburg position at anaesthetic induction and manual application of positive end-expiratory pressure (PEEP) is recommended. Intra-operative hypoxaemia can be treated with the combination of PEEP and recruitment manoeuvres, and attention to airway management at emergence is critical. Local anaesthetic wound infiltration and non-steroidal anti-inflammatory drugs should be part of multimodal opioid-sparing postoperative analgesia. Implementation of bariatric clinical-care pathways seems beneficial. Considering the prevalence of sleep apnoea in these patients, outpatient bariatric surgery remains controversial, but is probably safe for certain procedures, provided there is strict adherence to preoperative eligibility and home-care protocols.

Evidence-based German guidelines for surgery for obesity

BACKGROUND

The young field of obesity surgery (bariatric surgery) in Germany expands as a consequence of the rapid increase of overweight and obesity. New surgical methods, minimal access techniques, and the enormous increase of scientific studies and evidence, all contribute to the success of bariatric surgery, which is the only realistic chance of permanent weight loss and regression of secondary diseases in many cases.

METHODS

A systematic literature review, classification of evidence, graded recommendations, and interdisciplinary consensus.

RESULTS

Obesity surgery is an integral component of the multimodal treatment of obesity, which consists of multidisciplinary evaluation and preparation, conservative and surgical treatment elements, and a life-long follow-up. The guideline confirms the body mass index (BMI)-based spectrum of indications (BMI > 40 kg/m(2) or >35 kg/m(2) with secondary diseases) and extends it through elimination of all age restrictions (>18 years and <60 years) and most of the contraindications. Precondition for surgery is the failure of a structured conservative program of 6-12 months or the expected futility of it. Type II diabetes mellitus becomes an independent indication criterion for BMI < 35 kg/m(2) (metabolic surgery). The standard techniques are gastric balloon, gastric banding, gastric bypass, gastric sleeve, and biliopancreatic diversion. The choice of procedure is based on profound knowledge of results, long-term effects, complications, and patient-specific circumstances. The after-care should be structured and organized long term.

CONCLUSION

The S3-guidelines contain evidence-based recommendations for the indication, selection of procedure, technique, and follow-up. Patient care should improve after implementation of these guidelines in clinical practice. Compliance by decision makers and health insurers is warranted.

The NAMES assessment: a novel combined-modality screening tool for obstructive sleep apnea

PURPOSE

Obstructive sleep apnea (OSA) remains underdiagnosed, despite our understanding of its impact on general health. Current screening methods utilize either symptoms or physical exam findings suggestive of OSA, but not both. The purpose of this study was to develop a novel screening tool for the detection of OSA, the NAMES assessment (neck circumference, airway classification, comorbidities, Epworth scale, and snoring), combining self-reported historical factors with physical exam findings.

METHODS

Subjects were adults without previously diagnosed OSA, referred to a community sleep center for suspicion of OSA. General health, Epworth Sleepiness Scale (ESS), and Berlin questionnaires were completed, and a physical exam focusing on modified Friedman (MF) grade, body mass index (BMI), and neck circumference (NC) was performed prior to polysomnography. OSA was defined by a respiratory disturbance index ≥15. Each variable was dichotomized, and cutoff values were determined for the NAMES tool in a pilot group of 150 subjects. The NAMES score was calculated from NC, MF, comorbidities, ESS, and loud snoring values. The performances of the NAMES, Berlin questionnaire, and ESS screening tests in predicting OSA were then compared in a validation group of 509 subjects.

RESULTS

In the pilot population, the cutoff value for the composite NAMES tool was calculated at ≥3 points. In the validation group, NAMES demonstrated similar test characteristics to the Berlin questionnaire, and sensitivity was better than that seen with the Epworth scale. The addition of BMI and gender to the tool improved screening characteristics.

CONCLUSIONS

The NAMES assessment is an effective, inexpensive screening strategy for moderate to severe OSA.

Obstructive sleep apnea: preoperative assessment

Obstructive sleep apnea is the most prevalent breathing disturbance in sleep. It is linked to a host of preexisting medical conditions, and associated with poorer postoperative outcomes. Screening and vigilance during the preoperative assessment identifies patients at high risk of obstructive sleep apnea. Further diagnostic tests may be performed, and plans can be made for tailored intraoperative care. The STOP and the STOP-Bang questionnaires are useful screening tools. Patients with a known diagnosis of obstructive sleep apnea should be seen in the preoperative clinic, where risk stratification and optimization may be done before surgery. This review article presents functional algorithms for the perioperative management of obstructive sleep apnea based on limited clinical evidence, and a collation of expert knowledge and practices. These recommendations may be used to assist the anesthesiologist in decision-making when managing the patient with obstructive sleep apnea.

Update on best practice recommendations for anesthetic perioperative care and pain management in weight loss surgery, 2004-2007

To reevaluate and update evidence-based best practice recommendations published in 2004 for anesthetic perioperative care and pain management in weight loss surgery (WLS), we performed a systematic search of English-language literature on anesthetic perioperative care and pain management in WLS published between April 2004 and May 2007 in MEDLINE and the Cochrane Library. We identified relevant abstracts by using key words, retrieved full text articles, and stratified the resulting evidence according to systems used in established evidence-based models. We updated prior evidence-based best practice recommendations based upon interim literature. In instances of controversial or inadequate scientific evidence, the task force reached consensus recommendations following evaluation of the best available information and expert opinion. The search yielded 1,788 abstracts, with 162 potentially relevant titles; 45 were reviewed in detail. Despite more information on perioperative management of patients with obstructive sleep apnea (OSA), evidence to support preoperative testing and treatment or to guide perioperative monitoring is scarce. New evidence on appropriate intraoperative dosing of muscle relaxants allows for greater precision in their use during WLS. A novel application of alpha-2 agonists for perioperative anesthetic care is emerging. Key elements that may enhance patient safety include integration of the latest evidence on WLS, obesity, and collaborative multidisciplinary care into clinical care. However, large gaps remain in the evidence base.

Postoperative CPAP and BiPAP use can be safely omitted after laparoscopic Roux-en-Y gastric bypass

BACKGROUND

Obstructive sleep apnea (OSA) is prevalent in the morbidly obese population. The need for routine preoperative testing for OSA has been debated in bariatric surgery publications. Most investigators have advocated the use of continuous positive airway pressure (CPAP) or bi-level positive airway pressure (BiPAP) in the postoperative setting; however, others have reported pouch perforations or other gastrointestinal complications as a result of their use. From a review of our experience, we present an algorithm for the safe postoperative treatment of patients with OSA without the use of CPAP or BiPAP.

METHODS

From January 2003 to December 2007, 1095 laparoscopic Roux-en-Y gastric bypasses were performed at our institution. Preoperative testing for OSA was not routinely performed. A prospective database was maintained. The data included patient demographics, co-morbidities (including OSA and CPAP/BiPAP use), perioperative events, complications, and follow-up information. Patients with known OSA were not given CPAP/BiPAP after surgery. They were observed in a monitored setting during their inpatient stay, ensuring continuous oxygen saturation of >92%. All patients used patient-controlled analgesia, were trained in the use of incentive spirometry, and ambulated within a few hours of surgery. The outcomes were compared between the OSA patients using preoperative CPAP/BiPAP versus those with OSA without preoperative CPAP/BiPAP versus patients with no history of OSA.

RESULTS

A total of 811 patients were included in the study group with no known history of OSA. Of the 284 patients with a confirmed diagnosis of OSA, 144 were CPAP/BiPAP dependent. Statistically significant differences were present in age distribution and gender, with men having greater CPAP/BiPAP dependency. No significant differences were found in body mass index, length of stay, pulmonary complications, or deaths. One pulmonary complication occurred in the OSA, CPAP/BiPAP-dependent group, three in the OSA, non-CPAP group, and six in the no-known OSA group. No anastomotic leaks or deaths occurred in the series.

CONCLUSION

Postoperative CPAP/BiPAP can be safely omitted in laparoscopic Roux-en-Y gastric bypass patients with known OSA, provided they are observed in a monitored setting and their pulmonary status is optimized by aggressive incentive spirometry and early ambulation.