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

Epidemiology of perioperative RV dysfunction: risk factors, incidence, and clinical implications

In this edition of the journal, the Perioperative Quality Initiative (POQI) present three manuscripts describing the physiology, assessment, and management of right ventricular dysfunction (RVD) as pertains to the perioperative setting. This narrative review seeks to provide context for these manuscripts, discussing the epidemiology of perioperative RVD focussing on definition, risk factors, and clinical implications. Throughout the perioperative period, there are many potential risk factors/insults predisposing to perioperative RVD including pre-existing RVD, fluid overload, myocardial ischaemia, pulmonary embolism, lung injury, mechanical ventilation, hypoxia and hypercarbia, lung resection, medullary reaming and cement implantation, cardiac surgery, cardiopulmonary bypass, heart and lung transplantation, and left ventricular assist device implantation. There has however been little systematic attempt to quantify the incidence of perioperative RVD. What limited data exists has assessed perioperative RVD using echocardiography, cardiovascular magnetic resonance, and pulmonary artery catheterisation but is beset by challenges resulting from the inconsistencies in RVD definitions. Alongside differences in patient and surgical risk profile, this leads to wide variation in the incidence estimate. Data concerning the clinical implications of perioperative RVD is even more scarce, though there is evidence to suggest RVD is associated with atrial arrhythmias and prolonged length of critical care stay following thoracic surgery, increased need for inotropic support in revision orthopaedic surgery, and increased critical care requirement and mortality following cardiac surgery. Acute manifestations of RVD result from low cardiac output or systemic venous congestion, which are non-specific to the diagnosis of RVD. As such, RVD is easily overlooked, and the relative contribution of RV dysfunction to postoperative morbidity is likely to be underestimated.We applaud the POQI group for highlighting this important condition. There is undoubtedly a need for further study of the RV in the perioperative period in addition to solutions for perioperative risk prediction and management strategies. There is much to understand, study, and trial in this area, but importantly for our patients, we are increasingly recognising the importance of these uncertainties.

Preoperative sleep-disordered breathing and craniofacial abnormalities are risk factors for postoperative sleep-disordered breathing in patients undergoing skin-flap oropharyngeal reconstruction surgery for oral cavity cancer: a prospective case-control study

PURPOSE

After oropharyngeal reconstruction surgery, excessive flap volume within the oral cavity may increase the risk of pharyngeal obstruction during sleep. This prospective observational study aimed to test a hypothesis that the skin-flap oropharyngeal reconstructive surgery increases nocturnal apnea-hypopnea index (nAHI, primary variable) after surgery.

METHODS

Adult patients undergoing oropharyngeal reconstruction surgery participated in this study. The hypothesis was tested by comparing the results of portable type 4 sleep study and craniofacial assessments with lateral head and neck computed tomography scout image before and after surgery. Multiple linear regression analyses were performed to identify predictors for nAHI increase after the surgery.

RESULTS

In 15 patients, a postoperative sleep study was performed at 41 (27, 59) (median (IQR)) days after the surgery. nAHI did not increase after the surgery (mean (95% CI), 13.0 (7.2 to 18.7) to 18.4 (10.2 to 26.6) events.hour-1, p = 0.277), while apnea index significantly increased after the surgery (p = 0.026). Use of the pedicle flap for the oropharyngeal reconstruction (p = 0.051), small mandible (p = 0.008), longer lower face (0.005), and larger tongue size (p = 0.008) were independent predictors for worsening of nAHI after surgery. Hospital stay was significantly longer in patients with the pedicle flap (n = 8) than in those with the free flap (n = 7) (p = 0.014), and the period of hospital stay was directly associated with increase of nAHI after surgery (r = 0.788, p < 0.001, n = 15).

CONCLUSIONS

Oropharyngeal reconstruction surgery worsens sleep-disordered breathing in some patients with craniofacial and surgical risk factors.

TRIAL REGISTRATION

UMIN Clinical Trial Registry (UMIN000036260, March 22, 2019), https://rctportal.niph.go.jp/s/detail/um?trial_id=UMIN000036260.

Complications and predictors associated with moderate to severe obstructive sleep apnoea in bariatric surgery: Evaluation of routine obstructive sleep apnoea screening

PURPOSE

Obstructive sleep apnoea (OSA) is a breathing disorder resulting in blockage of airflow and hypo-oxygenation. The incidence of OSA in patients with class 2 or 3 obesity (Body Mass index, BMI >35) is 60-70%. Unfortunately, most bariatric patients are unaware they suffer from OSA. Untreated OSA can lead to perioperative cardiopulmonary complications. The aim of this study was to identify predictors associated with moderate to severe OSA and asses the incidence of OSA-related complications in a large cohort of patients who underwent OSA-screening and treatment if indicated before bariatric surgery.

METHODS

All consecutive patients who underwent primary bariatric surgery between September 2013 and September 2019 were included. Univariable and multivariable logistic regression analysis was performed to identify potential predictors for moderate to severe OSA using sleep studies.

RESULTS

A total of 2872 patients who underwent bariatric surgery were included for analysis. Overall, OSA was identified in 62.5% of all patients and moderate to severe OSA (AHI ≥15) in 28.6%. Independent predictors for moderate to severe OSA were male gender (p < 0.001), age (p < 0.001), preoperative BMI (p < 0.001), preoperative waist circumference (p < 0.001), hypertension (p < 0.001), and dyslipidaemia (p = 0.046). The incidence of OSA-related complications was low (0.8%) and not significantly different among the different OSA severity classes.

CONCLUSION

This is the largest study to assess OSA presence and OSA-related complications in patients undergoing bariatric surgery. The incidence of potential OSA-related complications was low (0.8%). We believe focus could be shifted towards more cost-efficient strategies where OSA screening is omitted such as perioperative continuous monitoring.

Anesthesia for Morbidly Obese Patients

BACKGROUND

The prevalence of morbid obesity (BMI >35 kg/m2) has risen steadily in recent decades. With the corresponding rise in the number of bariatric operations, anesthesiologists deal with this patient group more commonly than before, particularly in specialized centers.

METHODS

This review is based on publications retrieved by a selective search in PubMed, including current guidelines and recommendations issued by specialist societies, as well as expert opinion.

RESULTS

In the anesthesiological care of morbidly obese patients, a preoperative assessment and risk stratification are just as important as the thoughtful selection of the anesthesia technique, the drugs used and their dosage, and perioperative management. A thorough understanding of the pathophysiological changes and comorbidities of morbid obesity and the associated risks is essential. The risk of pulmonary complications such as respiratory failure, hypoxia, and apnea is markedly higher in morbidly obese patients, especially those with obstructive sleep apnea. Short-acting, less lipophilic anesthetic drugs are particularly useful, as is multimodal pain therapy for the avoidance of high opiate doses. The indication for intensified postoperative monitoring depends on the patient's preexisting illnesses, the type of anesthesia, and the type of surgical procedure. Regional anesthetic techniques should be used if possible.

CONCLUSION

The perioperative care of morbidly obese patients presents special challenges. The anesthesiologist must be aware of potential comorbidities, specific risks, and pathophysiological changes in order to provide adequate care to this patient group.

A Novel Clinical Tool to Detect Severe Obstructive Sleep Apnea

Purpose

Obstructive sleep apnea (OSA) is a disease with high morbidity and is associated with adverse health outcomes. Screening potential severe OSA patients will improve the quality of patient management and prognosis, while the accuracy and feasibility of existing screening tools are not so satisfactory. The purpose of this study is to develop and validate a well-feasible clinical predictive model for screening potential severe OSA patients.

Patients and Methods

We performed a retrospective cohort study including 1920 adults with overnight polysomnography among which 979 cases were diagnosed with severe OSA. Based on demography, symptoms, and hematological data, a multivariate logistic regression model was constructed and cross-validated and then a nomogram was developed to identify severe OSA. Moreover, we compared the performance of our model with the most commonly used screening tool, Stop-Bang Questionnaire (SBQ), among patients who completed the questionnaires.

Results

Severe OSA was associated with male, BMI≥ 28 kg/m2, high blood pressure, choke, sleepiness, apnea, white blood cell count ≥9.5×109/L, hemoglobin ≥175g/L, triglycerides ≥1.7 mmol/L. The AUC of the final model was 0.76 (95% CI: 0.74-0.78), with sensitivity and specificity under the optimal threshold selected by maximizing Youden Index of 73% and 66%. Among patients having the information of SBQ, the AUC of our model was statistically significantly greater than that of SBQ (0.78 vs 0.66, P = 0.002).

Conclusion

Based on common clinical examination of admission, we develop a novel model and a nomogram for identifying severe OSA from inpatient with suspected OSA, which provides physicians with a visual and easy-to-use tool for screening severe OSA.

Patient Characteristics and Clinical and Economic Outcomes Associated with Unplanned Medical and Surgical Intensive Care Unit Admissions: A Retrospective Analysis

Purpose

To characterize medical and surgical patient characteristics, as well as clinical and economic outcomes, associated with unplanned intensive care unit (ICU) admissions.

Patients and Methods

This was a retrospective matched cohort analysis that utilized the PINC AITM Healthcare Database, which collects deidentified data from 25% of United States (US) hospital admissions. Discharge records were assessed for medical and surgical admissions in 2021. An unplanned ICU admission was defined as direct transfer from a medical, surgical, or telemetry unit to the ICU. Patients with and without an unplanned ICU admission were 1:1 propensity score matched. Differences between patients with and without unplanned ICU admissions were assessed using two-sample t-tests for continuous measures and Chi-square tests for categorical measures.

Results

A total of 3,807,124 qualifying admissions were identified. Medical admissions with unplanned ICU transfers were more likely to be urgent/emergent (odds ratio [OR] 2.9, 95% confidence interval [CI 2.7-3.0], p<0.0001), with patient characteristics including male sex (1.4, [1.4-1.4], p<0.0001), obesity (1.7, [1.6-1.7], p<0.0001), and increased Charlson Comorbidity Index (CCI=1: 1.8, [1.8-1.9], p<0.0001; CCI≥5: 3.2, [3.1-3.3], p<0.0001). Surgical admissions with unplanned ICU transfers were more likely to be urgent/emergent (3.1, [2.9-3.2], p<0.0001) and with patients of higher CCI (2.5, [2.3-2.6], p<0.0001 to a CCI of≥5 (7.9, [7.4-8.4], p<0.0001). Between matched medical patients, mean differences in length of stay, cost, and mortality were 4.1 days (p<0.0001), $13,424 (p<0.0001), and 21% (p<0.0001), respectively. Between matched surgical patients, mean differences in these outcomes were 6.4 days (p<0.0001), $21,448 (p<0.0001), and 14% (p<0.0001), respectively.

Conclusion

Emergency care in patients with a higher co-morbid burden is more likely to lead to unplanned ICU admission, putting patients at a significantly increased chance of mortality, longer length of stay, and increased costs. Improving care and monitoring of patients outside the ICU may help detect early changes in pathophysiology and enable early intervention.

The impact of semi-upright position on severity of sleep disordered breathing in patients with obstructive sleep apnea: a two-arm, prospective, randomized controlled trial

BACKGROUND

The severity of sleep-disordered breathing is known to worsen postoperatively and is associated with increased cardio-pulmonary complications and increased resource implications. In the general population, the semi-upright position has been used in the management of OSA. We hypothesized that the use of a semi-upright position versus a non-elevated position will reduce postoperative worsening of OSA in patients undergoing non-cardiac surgeries.

METHODS

This study was conducted as a prospective randomized controlled trial of perioperative patients, undergoing elective non-cardiac inpatient surgeries. Patients underwent a preoperative sleep study using a portable polysomnography device. Patients with OSA (apnea hypopnea index (AHI) > 5 events/hr), underwent a sleep study on postoperative night 2 (N2) after being randomized into an intervention group (Group I): semi-upright position (30 to 45 degrees incline), or a control group (Group C) (zero degrees from horizontal). The primary outcome was postoperative AHI on N2. The secondary outcomes were obstructive apnea index (OAI), central apnea index (CAI), hypopnea index (HI), obstructive apnea hypopnea index (OAHI) and oxygenation parameters.

RESULTS

Thirty-five patients were included. Twenty-one patients were assigned to the Group 1 (females-14 (67%); mean age 65 ± 12) while there were fourteen patients in the Group C (females-5 (36%); mean age 63 ± 10). The semi-upright position resulted in a significant reduction in OAI in the intervention arm (Group C vs Group I postop AHI: 16.6 ± 19.0 vs 8.6 ± 11.2 events/hr; overall p = 0.01), but there were no significant differences in the overall AHI or other parameters between the two groups. Subgroup analysis of patients with "supine related OSA" revealed a decreasing trend in postoperative AHI with semi-upright position, but the sample size was too small to evaluate statistical significance.

CONCLUSION

In patients with newly diagnosed OSA, the semi-upright position resulted in improvement in obstructive apneas, but not the overall AHI.

TRIAL REGISTRATION

This trial was retrospectively registered in clinicaltrials.gov NCT02152202 on 02/06/2014.

Insights into the Use of Point-of-Care Ultrasound for Diagnosing Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a sleeping disorder caused by complete or partial disturbance of breathing during the night. Existing screening methods include questionnaire-based evaluations which are time-consuming, vary in specificity, and are not globally adopted. Point-of-care ultrasound (PoCUS), on the other hand, is a painless, inexpensive, portable, and useful tool that has already been introduced for the evaluation of upper airways by anesthetists. PoCUS could also serve as a potential screening tool for the diagnosis of OSA by measuring different airway parameters, including retropalatal pharynx transverse diameter, tongue base thickness, distance between lingual arteries, lateral parapharyngeal wall thickness, palatine tonsil volume, and some non-airway parameters like carotid intima-media thickness, mesenteric fat thickness, and diaphragm characteristics. This study reviewed previously reported studies to highlight the importance of PoCUS as a potential screening tool for OSA.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

The effectiveness of supplemental oxygen and high-flow nasal cannula therapy in patients with obstructive sleep apnea in different clinical settings: A systematic review and meta-analysis

STUDY OBJECTIVE

To evaluate the effectiveness of supplemental oxygen therapy and high-flow nasal cannula (HFNC) therapy in patients with obstructive sleep apnea (OSA) in different clinical settings to assess its application to surgical patients in the postoperative setting.

DESIGN

A systematic search was conducted on MEDLINE and other databases from 1946 to December 16th, 2021. Title and abstract screening were conducted independently, and the lead investigators resolved conflicts. Meta-analyses were performed using a random-effects model and are presented as mean difference and standardized mean difference with 95% confidence intervals. These were calculated using RevMan 5.4.

PATIENTS

1395 and 228 OSA patients underwent oxygen therapy and HFNC therapy respectively.

INTERVENTIONS

Oxygen therapy and HFNC therapy.

MEASUREMENTS

Apnea-hypopnea index (AHI), oxyhemoglobin saturation (SpO₂), cumulative time with SPO₂ < 90% (CT90).

MAIN RESULTS

Twenty-seven oxygen therapy studies were included in the review, with ten randomized controlled trials (RCT), seven randomized crossovers, seven non-randomized crossovers, and three prospective cohorts. Pooled analyses showed that oxygen therapy significantly reduced AHI by 31% and increased SpO₂ by 5% versus baseline, and CPAP significantly reduced AHI by 84%, and increased SpO₂ by 3% versus baseline. CPAP was 53% more effective in reducing AHI than oxygen therapy, but both treatments had similar effectiveness in increasing SpO₂. Nine HFNC studies were included in the review, with five prospective cohorts, three randomized crossovers, and one RCT. Pooled analyses showed that HFNC therapy significantly reduced AHI by 36% but did not substantially increase SpO₂.

CONCLUSIONS

Oxygen therapy effectively reduces AHI and increases SpO₂ in patients with OSA. CPAP is more effective in reducing AHI than oxygen therapy. HFNC therapy is effective in reducing AHI. Although both oxygen therapy and HFNC therapy effectively reduce AHI, more research is needed to draw conclusions on clinical outcomes.

A bibliometric analysis of obstructive sleep apnea and anesthesia

To conduct a bibliographic analysis of obstructive sleep apnea (OSA) which has reached epidemic proportions and is a frequent, unknown, and important cause of perioperative morbidity and mortality, by examining the internationally most cited articles. For OSA, the most cited articles in the field of anesthesiology and reanimation, appropriate access terms were compiled and combined, and related publications were searched using the Thompson Reuters Web of Science Citation Indexing search engine. A total of 79 journal publications were found on OSA and anesthesia, with an average of 14.86 citations per article. The most cited publication was the "Society for Ambulatory Anesthesia Consensus Statement on Preoperative Selection of Adult Patients with Obstructive Sleep Apnea Scheduled for Ambulatory Surgery" published in the journal Anesthesia and Analgesia and was conducted by Joshi et al. It was found that 38 of the 79 studies reached as a result of the search were articles, and the average number of citations was 21.13. The Hirsch index of these articles, which were cited 803 times in total, was 15. A total of 31 articles (81.57%) were cited at least once, while the remaining 7 articles (18.43%) were not cited at all. The majority of the articles obtained are from the research fields of anesthesiology (n = 20; 52.63%), followed by otorhinolaryngology (n = 5; 13.15%), pediatrics (n = 5; 13.15%), respiratory system (n = 5; 13.15%), internal medicine (n = 4; 10.52%), and the rest were in various fields. Publications on "Obstructive Sleep Apnea" and "Anesthesia" have increased rapidly in the last decade. Anesthesia management and airway safety, patient management, including pain control in the postoperative period, and noninvasive mechanical ventilation treatment methods, such as continuous positive airway pressure, are hot topics.

Evaluation of the Effects of an Extubation Protocol With Neostigmine on Duration of Mechanical Ventilation After Cardiac Surgery

OBJECTIVES

Residual neuromuscular blockade is associated with increased postoperative pulmonary complications. This study aimed to evaluate the effect of an extubation protocol incorporating neuromuscular blockade reversal (NMBR) by train-of-four monitoring on "fast-track" cardiac surgery outcomes.

DESIGN

A retrospective cohort study.

SETTING

At a university hospital.

PARTICIPANTS

Out of 1,843 cardiac surgery patients, from February 2, 2015, to March 31, 2017, 957 (52%) underwent cardiac surgery on or after February 29, 2016.

INTERVENTIONS

An extubation protocol, comprised of weaning from mechanical ventilation and NMBR guidelines, was implemented on February 29, 2016.

MEASUREMENTS AND MAIN RESULTS

The associations of baseline characteristics with the postoperative duration of mechanical ventilation (primary outcome) and respiratory and/or adverse complications (secondary outcomes) were evaluated using regression and interrupted- time series models. The implementation of an extubation protocol was associated with an 18% decrease in the duration of mechanical ventilation (incident rate ratio [IRR] 0.82, 95% CI 0.72-0.94; p < 0.01), statistically insignificant 26% increase in patients extubated ≤6 hours (odds ratio [OR] 1.26, 95% CI 0.97-1.65; p = 0.09), and 13% shorter intensive care unit length of stay (LOS) (IRR 0.87, 95% CI 0.79-0.97; p < 0.01). Patients undergoing isolated coronary artery bypass graft or isolated valve procedures, on or after February 29, 2016, had decreased extubation times (IRR 0.82, p < 0.01 and IRR 0.80, p = 0.02). The protocol did not have a statistically significant association with hospital LOS (IRR 0.98, p = 0.57) or readmission (OR 1.22, p = 0.33), and differences in the occurrence of pulmonary complications and adverse outcomes between the pre- and postprotocol groups were clinically insignificant.

CONCLUSIONS

The application of an extubation protocol incorporating NMBR based on neuromuscular monitoring was associated with a decrease in postoperative duration of mechanical ventilation and facilitated more patients meeting the early extubation benchmark without an increased risk of respiratory complications or adverse outcomes.

Sleep study measures on post-operative night one following expansion pharyngoplasty for obstructive sleep apnea

PURPOSE

To examine the changes in measures of sleep apnea severity and hypoxemia on the first post-operative night (PON1) following expansion pharyngoplasty as a means to assess the safety of same day discharge after surgery.

MATERIALS AND METHODS

Prospective cohort study of subjects with moderate-severe obstructive sleep apnea who underwent expansion pharyngoplasty at a single academic sleep surgical practice. A WatchPAT study was performed on the night immediately following surgery (PON1) and comparisons were made to baseline sleep testing.

RESULTS

Twenty subjects who had a mean age of 45.7 ± 10.8 years old and a mean body-mass index (BMI) of 31.4 ± 3.2 kg/m² were enrolled. Patients had baseline severe OSA with mean apnea hypopnea index (AHI) 39.4 ± 19.5/h, O2 nadir 80.8 ± 6.1 % and time with oxygen saturation below 88 % (T88) 12.3 ± 13.2 min. Measures of sleep apnea and nocturnal hypoxemia were not significantly different on PON1. AHI was increased by >20 % in 11 (55.0 %) patients. One patient demonstrated a >10 % worsening in O2 nadir, and 8 patients (45.0 %) demonstrated a >20 % worsening in T88. BMI over 32 was associated with elevated odds of worsening in T88, and anesthesia involving ketamine was associated with lower odds of a 20 % worsening in AHI or T88.

CONCLUSIONS

On PON1 following expansion pharyngoplasty, AHI and nocturnal hypoxemia are stable overall but variable on an individual basis. The decision for admission should therefore be made on a case-by-case basis. Further research is need to elucidate definitive predictors of worsening measures on PON1.

Level of Evidence of Guidelines for Perioperative Management of Patients With Obstructive Sleep Apnea: An Evaluation Using the Appraisal of Guidelines for Research and Evaluation II Tool

Currently, the quality of guidelines for the perioperative management of patients with obstructive sleep apnea (OSA) is unknown, leaving anesthesiologists to make perioperative management decisions with some degree of uncertainty. This study evaluated the quality of clinical practice guidelines regarding the perioperative management of patients with OSA. This study was reported in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search of the MedlineALL (Ovid) database was conducted from inception to February 26, 2021, for clinical practice guidelines in the English language. Quality appraisal of guidelines was evaluated using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) framework. Descriptive statistical analysis of each of the 6 domains was expressed as a percentage using the formula: (obtained score - minimum possible score)/(maximum possible score - minimum possible score). Of 192 articles identified in the search, 41 full texts were assessed for eligibility, and 10 articles were included in this review. Intraclass correlation coefficients of the AGREE II scores across the 7 evaluators for each guideline were each >0.9, suggesting that the consistency of the scores among evaluators was high. Sixty percent of recommendations were based on evidence using validated methods to grade medical literature, while the remainder were consensus based. The median and range scores of each domain were: (1) scope and purpose, 88% (60%-95%); (2) stakeholder involvement, 52% (30%-82%); (3) rigor of development, 67% (40%-90%); (4) clarity of presentation, 74% (57%-88%); (5) applicability, 46% (20%-73%); and (6) editorial independence, 67% (19%-83%). Only 4 guidelines achieved an overall score of >70%. This critical appraisal showed that many clinical practice guidelines for perioperative management of patients with OSA used validated methods to grade medical literature, such as Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) and Oxford classification, with lower scores for stakeholder involvement due to lack of engagement of patient partners and applicability domain due to lack of focus on the complete perioperative period such as postdischarge counseling. Future efforts should be directed toward establishing higher focus on the quality of evidence, stakeholder involvement, and applicability to the wider perioperative patient experience.

The effectiveness of positive airway pressure therapy in reducing postoperative adverse outcomes in surgical patients with obstructive sleep apnea: A systematic review and meta-analysis

IMPORTANCE

Obstructive sleep apnea (OSA) is prevalent in surgical patients and is associated with an increased risk of adverse perioperative events.

STUDY OBJECTIVE

To determine the effectiveness of positive airway pressure (PAP) therapy in reducing the risk of postoperative complications in patients with OSA undergoing surgery.

DESIGN

Systematic review and meta-analysis searching Medline and other databases from inception to October 17, 2021. The search terms included: "positive airway pressure," "surgery," "post-operative," and "obstructive sleep apnea." The inclusion criteria were: 1) adult patients with OSA undergoing surgery; (2) patients using preoperative and/or postoperative PAP; (3) at least one postoperative outcome reported; (4) control group (patients with OSA undergoing surgery without preoperative and/or postoperative PAP therapy); and (5) English language articles.

PATIENTS

Twenty-seven studies included 30,514 OSA patients undergoing non-cardiac surgery and 837 OSA patients undergoing cardiac surgery.

INTERVENTION

PAP therapy MAIN RESULTS: In patients with OSA undergoing non-cardiac surgery, PAP therapy was associated with a decreased risk of postoperative respiratory complications (2.3% vs 3.6%; RR: 0.72, 95% CI: 0.51-1.00, asymptotic P = 0.05) and unplanned ICU admission (0.12% vs 4.1%; RR: 0.44, 95% CI: 0.19-0.99, asymptotic P = 0.05). No significant differences were found for all-cause complications (11.6% vs 14.4%; RR: 0.89, 95% CI: 0.74-1.06, P = 0.18), postoperative cardiac and neurological complications, in-hospital length of stay, and in-hospital mortality between the two groups. In patients with OSA undergoing cardiac surgery, PAP therapy was associated with decreased postoperative cardiac complications (33.7% vs 50%; RR: 0.63, 95% CI: 0.51-0.77, P < 0.0001), and postoperative atrial fibrillation (40.1% vs 66.7%; RR: 0.59, 95% CI 0.45-0.77, P < 0.0001).

CONCLUSION

In patients with OSA undergoing non-cardiac surgery, PAP therapy was associated with a 28% reduction in the risk of postoperative respiratory complications and 56% reduction in unplanned ICU admission. In patients with OSA undergoing cardiac surgery, PAP therapy decreased the risk of postoperative cardiac complications and atrial fibrillation by 37% and 41%, respectively.

Volume Incentive Spirometry Reduces Pulmonary Complications in Patients After Open Abdominal Surgery: A Randomized Clinical Trial

Objective

To compare the effect of diaphragmatic breathing and volume incentive spirometry (VIS) on hemodynamics, pulmonary function, and blood gas in patients following open abdominal surgery under general anesthesia.

Methods

A total of 58 patients who received open abdominal surgery were randomly assigned to the control group (n=29) undergoing diaphragmatic breathing exercises and the VIS group (n=29) undergoing VIS exercises. All the participants performed the six-minute walk test (6MWT) preoperatively to evaluate their functional capacity. Hemodynamic indexes, pulmonary function tests, and blood gas indexes were recorded before surgery and on the 1st, 3rd, and 5th postoperative day.

Results

The functional capacity was not significantly different between the two groups during the preoperative period (P >0.05). At 3 days and 5 days postoperatively, patients in the VIS group had a significantly higher SpO2 than that in the control group (P <0.05). Pulmonary function test values were reduced in both two groups postoperatively when compared to the preoperative values but improved for three and five days afterward (P <0.05). Of note, the significantly elevated levels of peak expiratory flow (PEF), forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio were observed on the 1st, 3rd, and 5th postoperative days in the VIS group compared with those in the control group (P <0.05). Besides, bass excess (BE), and pH values were significantly higher in the VIS group on the 1st postoperative day than those in the control group (P <0.05).

Conclusion

Diaphragmatic breathing and VIS could improve postoperative pulmonary function, but VIS exercise might be a better option for improving hemodynamics, pulmonary function, and blood gas for patients after open abdominal surgery, hence lowering the incidence of postoperative pulmonary complications.

[The perioperative role of high-flow cannula oxygen (HFNO)]

High-flow nasal cannula oxygen (HFNO) is commonly used during the perioperative period. Its numerous physiological benefits, satisfactory tolerance and ease of use have led to its widespread application in intensive care and post-anesthesia care units. HFNO is also used in the operating theater in multiple indications: as oxygen supplementation (associated with pressurization) prior to orotracheal intubation; in digestive and bronchial endoscopies, especially in patients at risk of hypoxemia; and in intraoperative surgery requiring spontaneous ventilation (ENT, thoracic surgery…). During the postoperative period, HFNO can be used in a curative strategy for respiratory failure or in a prophylactic strategy to prevent reintubation. In a curative approach, HFNO seems of interest following cardiac or thoracic surgery but has not been evaluated in respiratory failure subsequent to abdominal surgery, in which case noninvasive ventilation remains the gold standard. The risk of respiratory complications depends on type of surgery and on patient comorbidities. As prophylaxis, HFNO is currently preferred to conventional oxygen therapy after cardiac or thoracic surgery, especially in patients at high risk of respiratory complications. For the clinician, it is important to acknowledge the limits of HFNO and to closely monitor patients receiving HFNO, the objective being to avoid delays in intubation that could lead to increased mortality.

Validation of the STOP-Bang questionnaire as a preoperative screening tool for obstructive sleep apnea: a systematic review and meta-analysis

BACKGROUND

Obstructive sleep apnea (OSA) is a common disorder that is highly associated with postoperative complications. The STOP-Bang questionnaire is a simple screening tool for OSA. The objective of this systematic review and meta-analysis is to evaluate the validity of the STOP-Bang questionnaire for screening OSA in the surgical population cohort.

METHODS

A systematic search of the following databases was performed from 2008 to May 2021: MEDLINE, Medline-in-process, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, PsycINFO, Journals @ Ovid, Web of Science, Scopus, and CINAHL. Continued literature surveillance was performed through October 2021.

RESULTS

The systematic search identified 4641 articles, from which 10 studies with 3247 surgical participants were included in the final analysis. The mean age was 57.3 ± 15.2 years, and the mean BMI was 32.5 ± 10.1 kg/m² with 47.4% male. The prevalence of all, moderate-to-severe, and severe OSA were 65.2, 37.7, and 17.0%, respectively. The pooled sensitivity of the STOP-Bang questionnaire for all, moderate-to-severe, and severe OSA was 85, 88, and 90%, and the pooled specificities were 47, 29, and 27%, respectively. The area under the curve for all, moderate-to-severe, and severe OSA was 0.84, 0.67, and 0.63.

CONCLUSIONS

In the preoperative setting, the STOP-Bang questionnaire is a valid screening tool to detect OSA in patients undergoing surgery, with a high sensitivity and a high discriminative power to reasonably exclude severe OSA with a negative predictive value of 93.2%.

TRIAL REGISTRATION

PROSPERO registration  CRD42021260451 .

Accuracy and modification of the STOP ‐bang questionnaire for screening patients with obstructive sleep apnea in China

Despite the high sensitivity of the STOP-Bang questionnaire [snoring, tiredness, observed apneas, high blood pressure, body mass index, age, neck size, gender] questionnaire (SBQ), which is widely used to screen individuals at high risk of obstructive sleep apnea (OSA), few studies have evaluated the discrimination related to sex in the SBQ. Therefore, our study aimed to assess whether SBQ performance is gender-related and modified by changing body mass index (BMI) and neck circumference (NC) cut-off values. A total of 470 patients attended the sleep centres. They were divided into moderate-to-severe OSA and non-moderate-to-severe OSA groups based on the apnea-hypopnea index (AHI) and the results of the SBQ screening. The predictive performance of the SBQ screening instrument was evaluated by 2 × 2 contingency tables and discriminatory ability, which was estimated from the area under the curve (AUC) obtained from receiver operating characteristic curve. Our results suggest that when screening for moderate-to-severe OSA, the original SBQ has higher sensitivity and lower specificity for men; however, women have higher specificity and lower sensitivity. The SBQ achieved the maximum AUC of 0.783 for men and 0.634 for women when the BMI cut-off value was established at 30 kg/m² and the NC cut-off value was established at 38 cm in men, and the BMI cut-off value was established at 25 kg/m² and the NC cut-off value at 36 cm in women. Balancing the optimal sensitivity and specificity, the cut-off value of the optimal modified SBQ total scores for men was determined to be ≥4 and ≥3 for women.

Characteristics of Patients with Unrecognized Sleep Apnea Requiring Postoperative Oxygen Therapy

Surgical patients with obstructive sleep apnea (OSA) have increased risk of perioperative complications. The primary objective is to determine the characteristics of surgical patients with unrecognized OSA requiring oxygen therapy for postoperative hypoxemia. The secondary objective is to investigate the characteristics of patients who were responsive to oxygen therapy. This was a post-hoc multicenter study involving patients with cardiovascular risk factors undergoing major non-cardiac surgery. Patients ≥45 years old underwent Type 3 sleep apnea testing and nocturnal oximetry preoperatively. Responders to oxygen therapy were defined as individuals with ≥50% reduction in oxygen desaturation index (ODI) on postoperative night 1 versus preoperative ODI. In total, 624 out of 823 patients with unrecognized OSA required oxygen therapy. These were mostly males, had larger neck circumferences, higher Revised Cardiac Risk Indices, higher STOP-Bang scores, and higher ASA physical status, undergoing intraperitoneal or vascular surgery. Multivariable regression analysis showed that the preoperative longer cumulative time SpO2 < 90% or CT90% (adjusted p = 0.03), and lower average overnight SpO2 (adjusted p < 0.001), were independently associated with patients requiring oxygen therapy. Seventy percent of patients were responders to oxygen therapy with ≥50% ODI reduction. Preoperative ODI (19.0 ± 12.9 vs. 14.1 ± 11.4 events/h, p < 0.001), CT90% (42.3 ± 66.2 vs. 31.1 ± 57.0 min, p = 0.038), and CT80% (7.1 ± 22.6 vs. 3.6 ± 8.7 min, p = 0.007) were significantly higher in the responder than the non-responder. Patients with unrecognized OSA requiring postoperative oxygen therapy were males with larger neck circumferences and higher STOP-Bang scores. Those responding to oxygen therapy were likely to have severe OSA and worse preoperative nocturnal hypoxemia. Preoperative overnight oximetry parameters may help in stratifying patients.

The prevention of delirium in elderly surgical patients with obstructive sleep apnea (PODESA): a randomized controlled trial

BACKGROUND

Obstructive sleep apnea (OSA) is associated with neurocognitive impairment - a known risk factor for postoperative delirium. However, it is unclear whether OSA increases the risk of postoperative delirium and whether treatment is protective. The objectives of this study were to identify OSA with a home sleep apnea test (HSAT) and to determine whether auto-titrating positive airway pressure (APAP) reduces postoperative delirium in older adults with newly diagnosed OSA undergoing elective hip or knee arthroplasty.

METHODS

We conducted a multi-centre, randomized controlled trial at three academic hospitals in Canada. Research ethics board approval was obtained from the participating sites and informed consent was obtained from participants. Inclusion criteria were patients who were [Formula: see text]0 years and scheduled for elective hip or knee replacement. Patients with a STOP-Bang score of ≥ 3 had a HSAT. Patients were defined as having OSA if the apnea-hypopnea index was ≥ 10/h. These patients were randomized 1:1 to either: 1) APAP for 72 h postoperatively or until discharge, or 2) routine care after surgery. The primary outcome was postoperative delirium, assessed twice daily with the Confusion Assessment Method for 72 h or until discharge or by chart review. The secondary outcome measures included length of stay, and perioperative complications occurring within 30 days after surgery.

RESULTS

Of 549 recruited patients, 474 completed a HSAT. A total of 234 patients with newly diagnosed OSA were randomized. The mean age was 68.2 (6.2) years and 58.6% were male. Analysis was performed on 220 patients. In total, 2.7% (6/220) patients developed delirium after surgery: 4.4% (5/114) patients in the routine care group, and 0.9% (1/106) patients in the treatment group (P = 0.21). The mean length of stay for the APAP vs. the routine care group was 2.9 (2.9) days vs. 3.5 (4.5) days (P = 0.24). On postoperative night 1, 53.5% of patients used APAP for 4 h/night or more, this decreased to 43.5% on night 2, and 24.6% on night 3. There was no difference in intraoperative and postoperative complications between the two groups.

CONCLUSIONS

We had an unexpectedly low rate of postoperative delirium thus we were unable to determine if postoperative delirium was reduced in older adults with newly diagnosed OSA receiving APAP vs. those who did not receive APAP after elective knee or hip arthroplasty.

TRIAL REGISTRATION

This trial was retrospectively registered in clinicaltrials.gov NCT02954224 on 03/11/2016.

Pre-operative screening for sleep disordered breathing: obstructive sleep apnoea and beyond

Sleep disordered breathing describes an important group of conditions that causes abnormal nocturnal gas exchange, with important implications in the peri-operative management plan. An understanding of the pathophysiology behind obstructive sleep apnoea and other disorders that may lead to hypoventilation can help to prevent complications. Patients with these disorders may be minimally symptomatic and it requires careful screening in the pre-operative assessment process for a diagnosis to be made. Decisions regarding initiation of therapy, such as positive airway pressure, and delay of the operation need to be carefully weighed up against the urgency of the surgical intervention. Planning of the peri-operative care, including the use of positive airway pressure therapy and appropriate post-operative monitoring, can help to avoid respiratory and cardiovascular morbidities and improve clinical outcomes.

Educational aims

To review different types of sleep disordered breathing and available screening methods in pre-operative assessment.To understand the pathophysiology behind sleep disordered breathing and how it can lead to complications in the peri-operative setting.To review the planning and treatment strategies that should be considered as part of peri-operative management.

Enhanced recovery after bariatric surgery: an Italian consensus statement

Background

Enhanced recovery after bariatric surgery (ERABS) is an approach developed to improve outcomes in obese surgical patients. Unfortunately, it is not evenly implemented in Italy. The Italian Society for the Surgery of Obesity and Metabolic Diseases and the Italian Society of Anesthesia, Analgesia, Resuscitation and Intensive Care joined in drafting an official statement on ERABS.

Methods

To assess the effectiveness and safety of ERABS and to develop evidence-based recommendations with regard to pre-, intra-, and post-operative care for obese patients undergoing ERABS, a 13-member expert task force of surgeons and anesthesiologists from Italian certified IFSO center of excellence in bariatric surgery was established and a review of English-language papers conducted. Oxford 2011 Levels of Evidence and U.S. Preventive Services Task Force Grade Definitions were used to grade the level of evidence and the strength of recommendations, respectively. The supporting evidence and recommendations were reviewed and discussed by the entire group at meetings to achieve a final consensus.

Results

Compared to the conventional approach, ERABS reduces the length of hospital stay and does not heighten the risk of major post-operative complications, re-operations, and hospital re-admissions, nor does it increase the overall surgical costs. A total of 25 recommendations were proposed, covering pre-operative evaluation and care (7 items), intra-operative management (1 item, 11 sub-items), and post-operative care and discharge (6 items).

Conclusions

ERABS is an effective and safe approach. The recommendations allow the proper management of obese patients undergoing ERABS for a better outcome.

A systematic review of the feasibility and safety of day case nasal and/or palatopharyngeal surgery in patients with obstructive sleep apnoea

INTRODUCTION

Recent guidelines suggest obstructive sleep apnoea (OSA) is not an absolute contraindication for same day discharge following surgery. The aim of this systematic review was to examine the feasibility and safety of day case nasal and/or palatopharyngeal surgery in patients with OSA.

METHODS

We performed a systematic search of PubMed, EMBASE and the Cochrane library. Quality assessment of included studies was done. The protocol of this systematic review was registered with PROSPERO (CRD42021273451).

RESULTS

A total of 1836 patients from ten observational studies were included. There were 268 (15.4%) nasal surgeries, 738 palatopharyngeal surgeries (42.4%) and 735 (42.2%) combined nasal and palatopharyngeal surgery. The majority of patients had moderate to severe OSA. A total of 860 patients (49.8%) were successfully discharged as day cases. There were no standard criteria for daycase surgery. Post-anaesthetic respiratory events were reported in 86/1750 (4.9%) patients. Oxygen desaturation was the most common respiratory event (83.7%, n = 72). There was no mortality reported.

CONCLUSION

Current data suggests day surgery is feasible in carefully selected patients with OSA undergoing nasal and/or palatopharyngeal surgery. Further well-designed prospective studies with an emphasis on the systematic assessment of complications are required to establish safety and daycase criteria.

Prevention of pulmonary complications in sedated patients undergoing interventional procedures in the nonoperating room anesthesia setting

PURPOSE OF REVIEW

Nonoperating room anesthesia (NORA) procedures have expanded in number, variety, and complexity. NORA involves all age groups, including frail older adults and patients often considered too sick to tolerate traditional surgical interventions. Postoperative pulmonary complications are a significant source of adverse events in the perioperative setting. We present a review focused on preventing pulmonary complications in the interventional NORA setting.

RECENT FINDINGS

NORA locations should function as independent, autonomous ambulatory units. We discuss a strategic plan involving a thorough preoperative evaluation of patients, including recognizing high-risk patients and their anesthetic management. Finally, we offer guidance on the challenges of conducting sedation and anesthesia in patients with coronavirus disease 2019 (COVID-19) or a history of COVID-19.

SUMMARY

The demands on the interventional NORA anesthesia team are increasing. Strategic planning, checklists, consistent staffing assignments, and scheduled safety drills are valuable tools to improve patient safety. In addition, through quality improvement initiatives and reporting, NORA anesthetists can achieve reductions in periprocedural pulmonary complications.

Cross-cultural adaptation and validation of the STOP-bang Questionnaire from English to Spanish as a tool for the early detection of sleep apnea syndrome in the surgical patient and in the general population

INTRODUCTION

Obstructive Sleep Apnea Syndrome (OSAS) or Apnea-Hypoapnea Syndrome (SAHS) is one of the most prevalent sleep disorders in the general population. It is associated with an increase in the prevalence of difficult orotracheal intubation and postoperative complications. The application of validated early detection tests, such the STOPbang test in English (STBC), is recommended; a test of high methodological quality, sensitivity and specificity in the early detection of SAHS in both surgical and general populations.

OBJECTIVE

The validation, translation, cross-cultural adaptation of the STBC to the Spanish population.

MATERIAL AND METHODS

The transcultural adaptation of the STBC to Spanish was carried out and a subsequent validation study with 77 consecutive patients was carried out. The statistical analysis evaluated the reliability, validity and feasibility of the translated and culturally adapted version.

RESULTS

44% of women and 56% of men were included, with a mean age of 53.58 ± 12.88 years. The reliability results were: a Cronbach's Alpha Coefficient of 0.767, a Pearson correlation r = 0.777 (P < .001) and a Sperman correlation rho = 0.455 (P = .044). The feasibility of the study was 100%. Criterion validity was evaluated using the Kappa coefficient, which was 0.444. For a score >3 of the questionnaire adapted to Spanish, the results of sensitivity, specificity according to the different cut-off levels of the apnea hypopnea index (AHI) >5, >15, >30) were: Sensitivity 87%, 91% and 100% respectively and Specificity of 50%, 31% and 22%.

CONCLUSIONS

The STBC questionnaire translated, adapted and validated into Spanish, evaluated in the present study, is reliable and valid with respect to the original design of the questionnaire. It is a useful tool that is easy to understand and implement, which can be used rigorously to stratify surgical risk and carry out adequate perioperative planning of those patients at risk of SAHS.

Impact of Opioid-Free Anesthesia on Analgesia and Recovery Following Bariatric Surgery: a Meta-Analysis of Randomized Controlled Studies

This meta-analysis aimed at exploring the impact of opioid-free anesthesia (OFA) on pain score and opioid consumption in patients undergoing bariatric surgery (BS). Literature search identified eight eligible trials. Forest plot revealed a significantly lower pain score (mean difference (MD) =  - 0.96, p = 0.0002; 318 patients), but not morphine consumption (MD =  - 5.85 mg, p = 0.1; 318 patients) at postoperative 24 h in patients with OFA than in those without. Pooled analysis also showed a lower pain score (p = 0.002), morphine consumption (p = 0.0003) in the postanesthetic care unit, and risk of postoperative nausea/vomiting (p = 0.0003) in the OFA group compared to the controls. In conclusion, this meta-analysis demonstrated that opioid-free anesthesia improved pain outcomes immediately and at 24 h after surgery without a beneficial impact on opioid consumption at postoperative 24 h. KEY POINTS: • Roles of opioid-free anesthesia (OFA) in bariatric surgery (BS) were investigated. • Outcomes included postoperative pain score, opioid use, and nausea/vomiting risk. • OFA was associated with lower 24-h pain score but not opioid consumption. • Lower pain score and opioid consumption were noted in the postanesthetic care unit. • OFA correlated with a lower risk of postoperative nausea/vomiting.

Periprocedural Management during Therapeutic Cardiac Catheterization in Patients with Sleep Apnea Syndrome: Report of Three Cases and Review of Literature

Most of the patients with sleep apnea syndrome (SAS) also known as sleep disordered breathing are not diagnosed before undergoing any cardiac interventional procedure. Many of them can safely undergo outpatient procedure under sedation or anesthesia. Few of them with moderate to severe grade of SAS, who are not optimized medically, may create problem and need special consideration. We managed three such cases in cardiac catheterization laboratory; two of them were not diagnosed before. The periprocedural problems we faced in these patients are narrated in this article along with review of literature. Some suggestions for management of such patients undergoing therapeutic cardiac catheterization are also highlighted.

Combination therapy of high-flow nasal cannula and upper body elevation for postoperative sleep disordered breathing; randomized cross-over trial

BACKGROUND

Low acceptance rate of continuous positive airway pressure therapy in postoperative patients with untreated obstructive sleep apnea (OSA) indicates the necessity for development of an alternative postoperative airway management strategy. We considered whether the combination of high-flow nasal cannula and upper body elevation could improve postoperative OSA.

METHODS

This non-blinded randomized crossover study performed at a single university hospital investigated the effect on a modified apnea hypopnea index, based exclusively on the airflow signal without arterial oxygen saturation criteria (flow-based apnea hypopnea index, primary outcome), of high-flow nasal cannula (20 liter.minute-1 with 40% oxygen concentration) with and without upper body elevation in patients with moderate to severe OSA. Preoperative sleep studies were performed at home (control, no head-of-bed elevation) and in hospital (30-degree head-of-bed elevation). On the first and second postoperative nights, high-flow nasal cannula was applied with or without 30-degree head-of-bed elevation, assigned in random order to 23 eligible participants.

RESULTS

Twenty-two out of the 23 (96%) accepted high-flow nasal cannula. Four participants resigned from the study. Control flow-based apnea hypopnea index (mean±SD: 59.6 ± 12.0 events.hour-1, n=19) was reduced by 14.7 (95% CI: 5.5 to 30.0) events.hour-1 with head-of-bed elevation alone (p=0.002), 10.9 (1.2 to 20.6) events.hour-1 with high-flow nasal cannula alone (p=0.028), and 22.5 (13.1 to 31.9) events.hour-1 with combined head-of-bed elevation and high-flow nasal cannula (p<0.001). Compared to sole high-flow nasal cannula, additional intervention with head-of-bed elevation significantly decreased flow-based apnea hypopnea index by 11.5 events.hour-1 (1.7 to 21.4) (p=0.022). High-flow nasal cannula, alone or in combination with head-of-bed elevation also improved overnight oxygenation. No harmful events were observed.

CONCLUSION

The combination of high-flow nasal cannula and upper body elevation reduced OSA severity and nocturnal hypoxemia, suggesting a role for it as an alternate postoperative airway management strategy.

Improving Bed Utilization in a Cohort of Bariatric Surgical Patients Using a Perioperative Obstructive Sleep Apnea Treatment and Bed Triage Protocol

BACKGROUND

Postoperative bariatric management often includes high-intensity monitoring for respiratory complications since > 70% of patients have obstructive sleep apnea. Given the increasing number of bariatric surgeries, there is a need to determine safe and cost-effective processes for postoperative care.The objective of this study was to determine if a novel triage and perioperative management guideline reduces postoperative monitoring and costs following bariatric surgery.

METHODS

Using a pre-post design, this is a retrospective analysis of 501 patients who had bariatric surgery. Half the patients were managed with usual care, and the other half received obstructive sleep apnea screening and treatment of moderate/severe obstructive sleep apnea with perioperative continuous positive airway pressure. The intervention group was triaged preoperatively to a postoperative nursing location based on risk factors.

RESULTS

There were no significant differences in demographics, comorbidities, frequency, or severity of OSA between groups. In the intervention group, there were fewer admissions to the intensive care unit (2.0% vs 9.1%; p < 0.01) and high acuity unit (9.6% vs 18.3%; p < 0.01). The length of stay was shorter in the intervention group (1.3 vs 2.3 days; p < 0.01) with a 50% reduction in costs. There were no statistically significant differences in the incidence of postoperative respiratory and non-respiratory complications between the two groups.

CONCLUSIONS

Most postoperative bariatric surgery patients can be safely managed on the surgical ward with monitoring of routine vitals alone if patients with moderate/severe obstructive sleep apnea receive perioperative continuous positive airway pressure.

Postoperative outcomes in surgical patients with obstructive sleep apnoea diagnosed by sleep studies: a meta-analysis and trial sequential analysis

Identifying surgical patients with obstructive sleep apnoea may assist with anaesthetic management to minimise postoperative complications. Using trial sequential analysis, we evaluated the impact of obstructive sleep apnoea diagnosed by polysomnography or home sleep apnoea testing on postoperative outcomes in surgical patients. Multiple databases were systematically searched. Outcomes included: total postoperative complications, systemic complications (cardiovascular, respiratory, neurological, renal, infectious) and specific complications (atrial fibrillation, myocardial infarction, combined hospital and intensive care unit re-admission, mortality). The pooled odds ratios of postoperative complications were evaluated by the Mantel-Haenszel method random-effects model. Meta-analysis and meta-regression were conducted, and the GRADE approach was used to evaluate the certainty of evidence. Twenty prospective cohort studies with 3756 patients (2127 obstructive sleep apnoea and 1629 non-obstructive sleep apnoea) were included (9 in non-cardiac surgery and 11 in cardiac surgery). Postoperative complications were almost two-fold higher with obstructive sleep apnoea, OR (95%CI) 1.92 (1.52-2.42), p < 0.001; certainty of evidence, moderate. Obstructive sleep apnoea was associated with a 1.5 times increased risk of postoperative cardiovascular complications, OR (95%CI) 1.56 (1.20-2.02), p = 0.001; certainty of evidence, moderate; an almost two-fold increase in respiratory complications, OR (95%CI) 1.91 (1.39-2.62), p < 0.001; certainty of evidence, moderate; and hospital and ICU re-admission, OR (95%CI) 2.25 (1.21-4.19), p = 0.01; certainty of evidence, low. Trial sequential analysis showed adequate information size for postoperative complications. Baseline confounding factors were adjusted by meta-regression, and the sub-group analysis did not materially change our results. This increased risk occurred especially in patients in whom obstructive sleep apnoea had been newly diagnosed, emphasising the importance of pre-operative screening.

Preoperative screening of patients at high risk of obstructive sleep apnea and postoperative complications: A systematic review and meta-analysis

STUDY OBJECTIVE

To determine the association between postoperative complications and a high versus low risk of obstructive sleep apnea (OSA) as determined via screening tools.

DESIGN

Systematic review and meta-analysis of cohort studies. PubMed, EMBASE, Web of Science, and the Cochrane Library were searched from their inception to January 5, 2021.

SETTING

Operating room, postoperative recovery area, and ward.

PATIENTS

Adult patients scheduled for surgery.

INTERVENTIONS

We used Review Manager 5.4 to pool the data. The quality of evidence was rated using the Grading of Recommendations, Assessment, Development and Evaluation system.

MEASUREMENTS

The primary outcome was the composite endpoint of postoperative respiratory complications. The secondary outcomes were postoperative cardiac and neurological complications, intensive care unit (ICU) admission, and mortality.

MAIN RESULTS

Twenty-six studies with 50,592 patients were included. A STOP-Bang score ≥ 3 (versus <3) was associated with higher incidences of postoperative respiratory (odds ratio [OR], 2.11; 95% confidence interval [CI], 1.66-2.68) and neurological complications (OR, 3.60; 95% CI, 1.56-8.31). A STOP-Bang score ≥ 5 (versus <5) was associated with higher incidences of postoperative respiratory (OR, 2.37; 95% CI, 1.11-5.04) and cardiac complications (OR, 4.95; 95% CI, 1.22-20.00) and higher in-hospital mortality (OR, 26.39; 95% CI, 2.89-241.30). A Berlin score ≥ 2 (versus <2) was not associated with the incidence of postoperative complications, ICU admission, or mortality. The quality of evidence for all outcomes was very low.

CONCLUSIONS

Very low-quality evidence suggested that a high risk of OSA, as assessed using the STOP-Bang questionnaire, was associated with a higher incidence of postoperative respiratory complications, and may also be associated with higher incidences of postoperative cardiac and neurological complications than a low risk of OSA. Since most of the included studies did not adjust for confounding factors, our findings need to be interpreted with caution. PROSPERO registration number: CRD42021220236.

Patients with sleep-disordered breathing for bariatric surgery

The prevalence of patients with obesity continues to rise worldwide and has reached epidemic proportions. There is a strong correlation between obesity and sleep-disordered breathing (SDB), and, in particular, obstructive sleep apnea (OSA). OSA is often undiagnosed in the surgical population. Bariatric surgery has been recognized as an effective treatment option for both obesity and OSA. Laparoscopic bariatric procedures, particularly laparoscopic sleeve gastrectomy (LSG), have become the most frequently performed procedures. OSA has been identified as an independent risk factor for perioperative complications and failure to recognize and prepare for patients with OSA is a major cause of postoperative adverse events, suggesting that all patients undergoing bariatric surgery should be screened preoperatively for OSA. These patients should be treated with an opioid-sparing analgesic plan and continuous positive airway pressure (CPAP) perioperatively to minimize respiratory complications. With the number of bariatric surgical patients with SDB likely to continue rising, it is critical to understand the best practices to manage this patient population.

Preoperative preparation and premedication of bariatric surgical patient

The prevalence of obesity has tripled worldwide over the past four decades. The United States has the highest rates of obesity, with 88% of the population being overweight and 36% obese. The UK has the sixth highest prevalence of obesity. The problem of obesity is not isolated to the developed world and has increasingly become an issue in the developing world as well. Obesity carries an increased risk of many serious diseases and health conditions, including type 2 diabetes, heart disease, stroke, sleep apnea, and certain cancers. Our ability to take care of this population safely throughout the perioperative period begins with a thorough and in-depth preoperative assessment and meticulous preparation. The preoperative assessment begins with being able to identify patients who suffer from obesity by using diagnostic criteria and, furthermore, being able to identify patients whose obesity is causing pathologic and physiologic changes. A detailed and thorough anesthesia assessment should be performed, and the anesthesia plan individualized and tailored to the specific patient's risk factors and comorbidities. The important components of the preoperative anesthesia assessment and patient preparation in the patient suffering from obesity include history and physical examination, airway assessment, medical comorbidities evaluation, functional status determination, risk assessment, preoperative testing, current weight loss medication, and review of any prior weight loss surgeries and their implications on the upcoming anesthetic. The preoperative evaluation of this population should occur with sufficient time before the planned operation to allow for modifications of the preoperative management without needing to delay surgery as the perioperative management of patients suffering from obesity presents significant practical and organizational challenges.

The Relationship Between Postoperative Opioid Analgesia and Sleep Apnea Severity in Patients Undergoing Hip Arthroplasty: A Randomized, Controlled, Triple-Blinded Trial

PURPOSE

Residual postoperative pain after hip arthroplasty is usually treated with oral opioids. While classic opioids are associated with respiratory depression and worsening of sleep apnea, tramadol has been reported to preserve respiratory function. However, this has not been investigated in a prospective trial using respiratory polygraphy. This randomized controlled triple-blinded trial tested the hypothesis that postoperative treatment with oral opioids such as oxycodone would increase sleep apnea severity, measured with a respiratory polygraphy, compared with oral tramadol.

PATIENTS AND METHODS

Sixty patients undergoing hip arthroplasty under spinal anesthesia with 15 mg isobaric bupivacaine 0.5% were randomized to receive postoperative pain treatment with either oral oxycodone (controlled-release 10 mg every 12 hours and immediate-release 5 mg every 4 hours as needed) or oral tramadol (controlled-release 100 mg every 8 hours and immediate-release 50 mg every 4 hours as needed). Respiratory polygraphy was performed on the first postoperative night. The primary outcome was the apnea-hypopnea index in the supine position. Secondary outcomes included the oxygen desaturation index, postoperative pain scores and intravenous morphine consumption.

RESULTS

Mean supine apnea-hypopnea index on postoperative night 1 was 11.3 events.h^-1 (95% confidence interval, 4.8-17.7) in the oxycodone group and 10.7 (4.6-16.8) events.h^-1 in the tramadol group (p=0.89). There were no significant differences between the oxycodone and tramadol groups with respect to any secondary sleep-related or pain-related outcomes.

CONCLUSION

Oral oxycodone did not increase sleep apnea severity measured using respiratory polygraphy compared with oral tramadol on the first postoperative night after hip arthroplasty.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov - NCT03454217 (date of registration: 05/03/2018).

Impact of a continuous enhanced cardio-respiratory monitoring pathway on cardio-respiratory complications after bariatric surgery: A retrospective cohort study

STUDY OBJECTIVE

To determine the impact of an enhanced monitoring pathway consisting of continuous postoperative cardio-respiratory monitoring on adverse outcomes after bariatric.

DESIGN

Single-center, retrospective cohort study.

PATIENTS

Adult patients who underwent bariatric surgeries between 2009 and 2016.

INTERVENTIONS

We evaluated the use of an enhanced monitoring pathway consisting of a distant, continuous, non-invasive respiratory monitoring system on postoperative cardio-respiratory complications in patients undergoing bariatric surgery. Treating physicians had the option to assign patients to enhanced monitoring (intervention group) in the postoperative period for suspected or diagnosed OSA or other clinical concerns. The control group had intermittent vital sign checks as per institutional standards.

MEASUREMENTS

The primary outcome was a composite of cardio-respiratory complications (rapid response team activation, intensive care admission, respiratory complications), major adverse cardiac events, and all-cause mortality. The secondary outcome was length of stay (LOS).

MAIN RESULTS

Of 1450 patients, 752 patients received enhanced monitoring (intervention) and 698 patients received standard monitoring (control). Univariate analysis showed that, compared to control, enhanced monitoring was associated with lower odds of composite cardio-respiratory complications (OR: 0.41, 95%CI: 0.32-0.53, p < 0.001) and lower odds of prolonged LOS > 2 days (OR: 0.37, 95% CI: 0.28-0.49, p < 0.001. After adjusting for potential confounders, enhanced monitoring remained associated with a reduction in composite cardio-respiratory complications (OR: 0.64, 95% CI: 0.46-0.88, p = 0.005).

CONCLUSIONS

Our study demonstrates that postoperative enhanced monitoring pathway was associated with a lower incidence of cardio-respiratory composite events, compared to a standard of care, in patients undergoing bariatric surgery. As our results show association rather than causation, future prospective randomized trials are needed to confirm the benefit of enhanced monitoring. Findings of our study add to the existing literature involved in clinical management pathways to reduce the incidence of adverse postoperative outcomes in high-risk patients undergoing inpatient surgeries.

The effect of transnasal humidified rapid-insufflation ventilator exchange (THRIVE) versus nasal prongs on safe apnoea time in paralysed obese patients: a randomised controlled trial

BACKGROUND

Evidence is lacking regarding the efficacy of Optiflow transnasal humidified rapid-insufflation ventilator exchange (THRIVE™) in obese patients. We compared the impact of this technique at 70 L min^-1 with 4 L min^-1 oxygen via nasal prongs on safe apnoea times of paralysed obese patients.

METHODS

We randomised adults with a BMI >35 kg m^-2 undergoing elective bariatric surgery. While apnoeic and paralysed, Group T received 70 L min^-1 oxygen via Optiflow THRIVE™. Group N received nasal prong oxygen at 4 L min^-1. The primary outcome was time to SpO₂ ≤95% while apnoeic, with a 360 s cut-off. This was analysed by applying a time-to-event analysis.

RESULTS

Forty-two patients were included. The median (inter-quartile range) BMI was 44.8 kg m^-2 (40.0-50.0) in Group T and 42.0 kg m^-2 (39.3-45.1) in Group N. Median (inter-quartile range) time to SpO₂ ≤95% in Group T was 356 (165 to ≥360) s and in Group N, 210 (160-270) s. Using a survival analysis framework, median time-to-event in Group T was 356 s (95% confidence interval 165 s-upper limit not defined) and 210 s (95% confidence interval 160-242 s) (P=0.049) in Group N.

CONCLUSIONS

Compared with oxygen delivered via nasal prongs at 4 L min^-1, oxygen delivery via Optiflow THRIVE™ at a flow rate of 70 L min^-1 can prolong safe apnoea time, however, the results are statistically inconclusive. Optiflow THRIVE™ did decrease the rate of reduction in Pa_o2 during apnoea.

CLINICAL TRIAL REGISTRATION

ANZCTR 12618000445279.

The influence of acute morphine use on obstructive sleep apnea: A systematic review and meta-analysis

The present study was conducted to systematically evaluate the acute effect of morphine on obstructive sleep apnea (OSA). The PubMed, Embase, Cochrane Library, Clinicaltrials.gov, China National Knowledge Infrastructure (CNKI), and Wan-Fang databases were searched for randomised controlled trials studying the influence of morphine on OSA published up to May 24, 2021. The Cochrane risk of bias tool was used to assess study quality and meta-analysis was performed on the included clinical trial results to quantify the impact of morphine on various sleep and respiratory parameters. Three studies (n = 132 patients) were ultimately examined. There were no significant differences between patients with OSA taking morphine and placebo/non-opioids with respect to the sleep Apnea-Hypopnea Index (mean difference [MD] 1.78, 95% confidence interval [CI] -2.41, 5.98; p > 0.05); Oxygen Desaturation Index (MD 1.49, 95% CI -3.21, 6.19; p > 0.05); Obstructive Sleep Apnea Index (MD 0.83, 95% CI -2.08, 3.75; p > 0.05); Hypopnea Index (MD -0.01, 95% CI -2.64, 2.63; p > 0.05); lowest oxygen saturation (MD 0.68, 95% CI -4.50, 5.86; p > 0.05); or sleep oxygen saturation >90% (MD 0.10, 95% CI -1.14, 1.34; p > 0.05). In conclusion, a single dose of 30 or 40 mg morphine does not have a significant effect on sleep or respiratory outcomes compared to placebo in patients with OSA, challenging the orthodoxy that opioids worsen OSA.

Presence of obstructive sleep apnea is associated with higher future readmissions and outpatient visits-a nationwide administrative dataset study

BACKGROUND

Hospital readmissions and outpatient visits contribute to the significant burden on healthcare systems. Obstructive sleep apnea (OSA) is a chronic medical condition that is associated with cardiovascular comorbidities and other chronic conditions. Inpatient and outpatient healthcare utilization rates in patients with OSA following hospitalization are unclear.

METHODS

This. retrospective case-control cohort study utilized a nationwide database to assess if OSA is associated with higher healthcare utilization post-hospitalization. We compared healthcare utilization among patients with OSA versus without OSA between 2009 and 2014 after matching for demographic variables, geographic location, hospital environment, reason for admission, and severity of illness during hospitalization. We measured future healthcare utilization by the number of ICU admissions, hospital admissions, emergency room visits, and outpatient visits after being discharged from the index hospitalization.

RESULTS

Two equal-sized cohorts comprised of 85,912 matched pairs were obtained. The OSA cohort demonstrated significantly higher rates of future ICU admissions, hospital admissions, emergency room visits, and outpatient visits. Matching for comorbid cardiovascular conditions continued to demonstrate higher healthcare utilization in the OSA group. Short-term outcomes during the index hospitalization were relatively similar between groups.

CONCLUSIONS

This retrospective database study demonstrated that OSA may be an independent marker of higher future healthcare utilization. On the other hand, the length of stay during the index hospitalization was not elevated. Prospective studies are needed to confirm these findings and investigate the impact of directing additional resources to inpatients with OSA.

Impact of Intraoperative Ketamine on Postoperative Analgesic Requirement Following Bariatric Surgery: a Meta-analysis of Randomized Controlled Trials

This meta-analysis aimed at exploring the impact of intravenous ketamine on pain relief and analgesic consumption in patients undergoing bariatric surgery (BS). Literature searches identified nine eligible trials with 458 participants. Forest plot revealed a significantly lower pain score [mean difference (MD) =  - 1.06, p = 0.005; 390 patients) and morphine consumption (MD =  - 3.85 mg, p = 0.01; 212 patients) immediately after BS in patients with intravenous ketamine than in those without. In contrast, pooled analysis showed comparable pain score (p = 0.28), morphine consumption (p = 0.45) within 24 h, and risk of postoperative nausea/vomiting (p = 0.67) between the two groups. In conclusion, the meta-analysis demonstrated improvements in pain outcomes immediately after surgery through perioperative intravenous ketamine administration despite the absence of analgesic benefit in the late postoperative period and a positive impact on postoperative nausea/vomiting.