Serum Biomarkers after Adenotonsillectomy for Pediatric OSA: A Systematic Review and Meta-Analysis

OBJECTIVE

To assess whether adenotonsillectomy improves levels of inflammatory and cardiometabolic markers in children with polysomnographically diagnosed obstructive sleep apnea (OSA).

DATA SOURCES

Two authors independently searched PubMed, Embase, and Cochrane databases up to August 16, 2022, for studies relating to pre- and post-operative levels of serum markers in pediatric patients undergoing adenotonsillectomy.

REVIEW METHODS

Data were extracted from included articles into a structured proforma. Meta-analyses of the standardized mean difference (SMD) were conducted in random-effects models. We calculated the probability of benefit (POB) and number needed to treat (NNT) for outcomes that demonstrated a statistically significant effect after adenotonsillectomy. The primary outcomes were changes in serum markers including C-reactive protein (CRP), high-sensitivity CRP (hs-CRP), Insulin-like growth factor 1 (IGF-1), interleukin-10 (IL-10), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), Brain natriuretic peptide (BNP), insulin, glucose, total cholesterol, triglyceride, low-density lipoprotein (LDL), high-density lipoprotein (HDL).

RESULTS

We screened 1616 studies and included 26 studies with 1331 participants. Meta-analysis was performed on 20 of the included studies. Adenotonsillectomy was associated with a significant decrease in insulin levels (SMD = -0.322, 95% Confidence Interval (CI) = -0.583 to -0.061), CRP (SMD = -0.946, 95% CI = -1.578 to -0.314), and BNP (SMD = -1.416, 95% CI = -2.355 to -0.477) and significant increase in levels of IGF-1 (SMD = 0.691, 95% CI = 0.207 to 1.176). There were no significant changes in levels of triglyceride, total cholesterol, TNF-α, LDL, HDL, glucose, IL-10, and IL-6.

CONCLUSION

In children with polysomnographically diagnosed OSA, adenotonsillectomy was associated with improvements in serum biomarkers, comprising lower CRP, insulin, and BNP, and higher IGF-1. Laryngoscope, 2024.

Simethicone use in drug-induced sleep endoscopy improves visibility

PURPOSE

To assess the effect of simethicone, a defoaming agent, on improving visibility during drug-induced sleep endoscopy (DISE) in obstructive sleep apnea (OSA).

METHODS

The study was a retrospective case-series study on patients with OSA who failed positive airway pressure (PAP) treatment. Patient parameters were recorded including age, BMI, neck and abdominal circumference, and apnea-hypopnea index (AHI). Comparisons were made between DISE procedures performed with and without the administration of simethicone. Visibility during DISE was independently graded by two surgeons, and inter-rater reliability was assessed.

RESULTS

Simethicone significantly improved DISE visibility (p = 0.03). "Best visibility" was achieved in 55% of cases with simethicone compared to 27% without simethicone (p = 0.02). Sub-analysis showed that only simethicone administration had a significant effect on visibility (p = 0.02). Inter-rater reliability between the grading surgeons was strong (Cohen-Kappa score 0.7, p < 0.001).

CONCLUSION

The findings suggest that simethicone enhances DISE visibility for OSA surgical planning. Further research should explore optimizing simethicone administration timing and the potential clinical implications for surgical outcomes and patient care.

Obstructive sleep apnoea and glaucoma: a systematic review and meta-analysis

INTRODUCTION

Obstructive sleep apnoea (OSA) has been thought to be associated with glaucoma, however there are many conflicting studies on this topic. With many new studies having been published since the previous meta-analysis, we believe it is important to clarify this association. Hence, in this study we meta-analyse the recent literature regarding the association between OSA and glaucoma.

METHODS

Pubmed, Embase, Scopus and Cochrane Library were searched from inception till the 28th February 2022 for observational as well as cross-sectional studies examining the association between OSA and glaucoma. Two reviewers selected studies, extracted data, graded the quality of included non-randomized studies using the Newcastle-Ottawa scale. The overall quality of evidence was assessed using GRADE. Random-effects models were used to meta-analyse the maximally covariate- adjusted associations.

RESULTS

48 studies were included in our systematic review, with 46 suitable for meta-analysis. Total study population was 4,566,984 patients. OSA was associated with a higher risk of glaucoma (OR 3.66, 95% CI 1.70 to 7.90, I2 = 98%, p < 0.01). After adjustment for various important confounders including age, gender and patient comorbidities such as hyperlipidaemia, hypertension, cardiovascular diseases and diabetes, patients with OSA had up to 40% higher odds of glaucoma. Substantial heterogeneity was eliminated through subgroup and sensitivity analyses after consideration of glaucoma subtype, OSA severity and adjustment for confounders.

CONCLUSIONS

In this meta-analysis, OSA was associated with higher risk of glaucoma, as well as more severe ocular findings characteristic of the glaucomatous disease process. We suggest more clinical studies looking into the effects of OSA treatment on the progression of glaucoma to help clinical decision making for patients.

The association of obstructive sleep apnea with blood and cerebrospinal fluid biomarkers of Alzheimer's dementia - A systematic review and meta-analysis

Alzheimer's disease (AD) is the most common type of dementia and is characterized by the aggregation of extracellular amyloid-beta and intracellular hyperphosphorylation of tau proteins. Obstructive Sleep Apnea (OSA) is associated with increased AD risk. We hypothesize that OSA is associated with higher levels of AD biomarkers. The study aims to conduct a systematic review and meta-analysis of the association between OSA and levels of blood and cerebrospinal fluid biomarkers of AD. Two authors independently searched PubMed, Embase, and Cochrane Library for studies comparing blood and cerebrospinal fluid levels of dementia biomarkers between patients with OSA and healthy controls. Meta-analyses of the standardized mean difference were conducted using random-effects models. From 18 studies with 2804 patients, meta-analysis found that cerebrospinal fluid amyloid beta-40 (SMD:-1.13, 95%CI:-1.65 to -0.60), blood total amyloid beta (SMD:0.68, 95%CI: 0.40 to 0.96), blood amyloid beta-40 (SMD:0.60, 95%CI: 0.35 to 0.85), blood amyloid beta-42 (SMD:0.80, 95%CI: 0.38 to 1.23) and blood total-tau (SMD: 0.664, 95% CI: 0.257 to 1.072, I² = 82, p<0.01, 7 studies) were significantly higher in OSA patients compared with healthy controls. These findings suggest that OSA is associated with an elevation of some biomarkers of AD.

A machine learning approach for the diagnosis of obstructive sleep apnoea using oximetry, demographic and anthropometric data

Introduction

Obstructive sleep apnoea (OSA) is a serious but underdiagnosed condition. Demand for the gold standard diagnostic polysomnogram (PSG) far exceeds its availability. More efficient diagnostic methods are needed, even in tertiary settings. Machine learning (ML) models have strengths in disease prediction and early diagnosis. We explored the use of ML with oximetry, demographic and anthropometric data to diagnose OSA.

Methods

A total of 2,996 patients were included for modelling and divided into test and training sets. Seven commonly used supervised learning algorithms were trained with the data. Sensitivity (recall), specificity, positive predictive value (PPV) (precision), negative predictive value, area under the receiver operating characteristic curve (AUC) and F1 measure were reported for each model.

Results

In the best performing four-class model (neural network model predicting no, mild, moderate or severe OSA), a prediction of moderate and/or severe disease had a combined PPV of 94%; one out of 335 patients had no OSA and 19 had mild OSA. In the best performing two-class model (logistic regression model predicting no-mild vs. moderate-severe OSA), the PPV for moderate-severe OSA was 92%; two out of 350 patients had no OSA and 26 had mild OSA.

Conclusion

Our study showed that the prediction of moderate-severe OSA in a tertiary setting with an ML approach is a viable option to facilitate early identification of OSA. Prospective studies with home-based oximeters and analysis of other oximetry variables are the next steps towards formal implementation.

Obstructive sleep apnea and the incidence and mortality of gastrointestinal cancers: a systematic review and meta-analysis of 5,120,837 participants

Background

Emerging evidence has shown higher overall cancer incidence in patients with obstructive sleep apnea. Gastrointestinal cancers, including esophageal, stomach, liver, pancreas, and colorectal cancers account for 26% of incident cancers. However, the link between gastrointestinal cancers and obstructive sleep apnea is still unclear. We performed a systematic review and meta-analysis (registered PROSPERO CRD42021220836) to investigate the association between obstructive sleep apnea and incidence of gastrointestinal cancer.

Methods

We searched four electronic databases (PubMed, Embase, Cochrane Library, Scopus) and included studies published from inception till 15th November 2020 reporting the association of obstructive sleep apnea with gastrointestinal cancer incidence. Extracted data was meta-analyzed in a random-effects model.

Results

A total of seven studies were included, forming a combined cohort of 5,120,837 patients. Studies which adjusted for demographics and comorbidities were included in meta-analysis. Among four studies with 7-11 years of median follow-up, patients with obstructive sleep apnea experienced increased incidence of colorectal cancer (HR 1.70, 95% CI: 1.48-1.96, I²=22%). Pancreatic cancer incidence was nominally increased in three studies (HR 1.36, 95% CI: 0.88-2.09, I²=96), though this was not statistically significant. There was no association between obstructive sleep apnea and liver cancer incidence among three studies (HR 0.99, 95% CI: 0.81-1.22, I²=84). However, the lack of a statistically significant relationship between obstructive sleep apnea and pancreatic cancer in our meta-analysis does not necessarily imply the true absence of an association.

Conclusions

An increased risk of colorectal cancer was seen in patients with obstructive sleep apnea among studies with long-term follow-up. Further research is required to explore the utility of incorporating obstructive sleep apnea screening into colorectal cancer screening guidelines to identify high-risk individuals and to confirm a possible association of obstructive sleep apnea with pancreatic cancer.

PROSPERO Registration

CRD42021220836.

Practising transoral robotic surgery in a middle-income country: surgical outcomes and early challenges

Transoral robotic surgery is a minimally invasive surgical technique that recently debuted in Malaysia. However, there are concerns over its cost, practicality, and feasibility in local settings. Our study aims to evaluate the surgical outcomes of transoral robotic surgery and discuss its learning curves. The clinical records of all patients who underwent transoral robotic surgery in a university hospital were reviewed. 25 patients were identified with a mean age of 43.9 years. The commonest indication was obstructive sleep apnoea (OSA) (76%), followed by base of tongue carcinoma (16%), recurrent tonsilitis and Wharton's duct cyst (4% each). For excision of tongue base in obstructive sleep apnoea without epiglottectomy, the mean operating time was 2.3(±0.9) hours with an average of 2.8(±0.4) days of hospital stay. The success rate for OSA surgery was seen in 78.9% of cases. The mean operating time for transoral excision of tongue base carcinoma was 4.3(±2.5) hours, whereas the mean hospital stay was 9(±3.6) days. All surgical margins were cleared with no recurrence except for one patient. The recurrent tumour was successfully excised via transoral robotic surgery, and he remained disease free after one year. The most frequent post-operative complaints were dysphagia, post-nasal drip, and hypogeusia. Transoral robotic surgery in Malaysia is in the commencement phase, where some pitfalls are expected. Opportunities should be given for more surgeons to acquire this technique so that minimally invasive surgery for head and neck diseases is readily available for patients in middle-income countries.

Improved Inflammatory and Cardiometabolic Profile After Soft-Tissue Sleep Surgery for Obstructive Sleep Apnea: A Systematic Review and Meta-analysis

Importance

Obstructive sleep apnea (OSA) is associated with a rise in serum inflammatory markers, which may be attenuated by sleep surgery.

Objective

To evaluate whether sleep surgery was associated with improved levels of proinflammatory markers in adults with OSA.

Data Sources

Two authors independently searched Cochrane, Embase, and PubMed databases from inception through June 14, 2022.

Study Selection

Two authors searched the Cochrane, Embase, and PubMed databases for studies comparing preoperative and postoperative levels of serum biomarkers in patients undergoing sleep surgery.

Data Extraction and Synthesis

Data were extracted from included articles into a structured proforma. Meta-analyses of the standardized mean difference (SMD) were conducted in random-effects models. To ensure relevance to clinicians and patients, the probability of benefit and number needed to treat were calculated for outcomes that demonstrated a statistically significant effect after sleep surgery.

Main Outcomes and Measures

The primary outcome was the preoperative and postoperative levels of serum biomarkers in patients undergoing sleep surgery, including C-reactive protein (CRP), glucose, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and interleukin-6 (IL-6). Data analysis was performed from April to May 2022.

Results

Of the 3218 studies screened, 26 studies with 1187 patients (mean [SD] age, 42.8 [11.1] years; 932 [78.5%] men and 255 [21.5%] women) were included. Soft-tissue sleep surgery was associated with a large decrease in CRP (SMD, -0.377; 95% CI, -0.617 to -0.137), total cholesterol (SMD, -0.267; 95% CI, -0.417 to -0.116), LDL (SMD, -0.201; 95% CI, -0.344 to -0.058), IL-6 (SMD, -1.086; 95% CI, -1.952 to -0.221), tumor necrosis factor-α (SMD, -0.822; 95% CI, -1.617 to -0.027), triglyceride (SMD, -0.186; 95% CI, -0.301 to -0.071), and leptin (SMD, -0.519; 95% CI, -0.954 to -0.083) in patients with OSA. Meta-regression highlighted that increased age, higher preoperative score for cumulative sleep time percentage with oxyhemoglobin saturation less than 90% (CT90), and greater change in CT90 postoperatively were associated with a greater decrease in serum CRP levels after soft-tissue sleep surgery. A greater reduction in apnea hypopnea index (AHI) was strongly associated with a greater reduction in total cholesterol and LDL. A greater reduction in body mass index and AHI were also associated with a greater increase in HDL.

Conclusions and Relevance

The findings of this systematic review and meta-analysis of 26 studies suggest that sleep surgery is associated with decreased levels of CRP, total cholesterol, LDL, triglyceride, IL-6, leptin, and TNF-α, which may improve the inflammatory and cardiometabolic profile of patients who undergo sleep surgery.

Prognosis and persistence of smell and taste dysfunction in patients with covid-19: meta-analysis with parametric cure modelling of recovery curves

OBJECTIVE

To clarify in patients with covid-19 the recovery rate of smell and taste, proportion with persistent dysfunction of smell and taste, and prognostic factors associated with recovery of smell and taste.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase, Scopus, Cochrane Library, and medRxiv from inception to 3 October 2021.

REVIEW METHODS

Two blinded reviewers selected observational studies of adults (≥18 years) with covid-19 related dysfunction of smell or taste. Descriptive prognosis studies with time-to-event curves and prognostic association studies of any prognostic factor were included.

DATA EXTRACTION AND SYNTHESIS

Two reviewers extracted data, evaluated study bias using QUIPS, and appraised evidence quality using GRADE, following PRISMA and MOOSE reporting guidelines. Using iterative numerical algorithms, time-to-event individual patient data (IPD) were reconstructed and pooled to retrieve distribution-free summary survival curves, with recovery rates reported at 30 day intervals for participants who remained alive. To estimate the proportion with persistent smell and taste dysfunction, cure fractions from Weibull non-mixture cure models of plateaued survival curves were logit transformed and pooled in a two stage meta-analysis. Conventional aggregate data meta-analysis was performed to explore unadjusted associations of prognostic factors with recovery.

MAIN OUTCOME MEASURES

The primary outcomes were the proportions of patients remaining with smell or taste dysfunction. Secondary outcomes were the odds ratios of prognostic variables associated with recovery of smell and taste.

RESULTS

18 studies (3699 patients) from 4180 records were included in reconstructed IPD meta-analyses. Risk of bias was low to moderate; conclusions remained unaltered after exclusion of four high risk studies. Evidence quality was moderate to high. Based on parametric cure modelling, persistent self-reported smell and taste dysfunction could develop in an estimated 5.6% (95% confidence interval 2.7% to 11.0%, I2=70%, τ2=0.756, 95% prediction interval 0.7% to 33.5%) and 4.4% (1.2% to 14.6%, I2=67%, τ2=0.684, 95% prediction interval 0.0% to 49.0%) of patients, respectively. Sensitivity analyses suggest these could be underestimates. At 30, 60, 90, and 180 days, respectively, 74.1% (95% confidence interval 64.0% to 81.3%), 85.8% (77.6% to 90.9%), 90.0% (83.3% to 94.0%), and 95.7% (89.5% to 98.3%) of patients recovered their sense of smell (I2=0.0-77.2%, τ2=0.006-0.050) and 78.8% (70.5% to 84.7%), 87.7% (82.0% to 91.6%), 90.3% (83.5% to 94.3%), and 98.0% (92.2% to 95.5%) recovered their sense of taste (range of I2=0.0-72.1%, τ2=0.000-0.015). Women were less likely to recover their sense of smell (odds ratio 0.52, 95% confidence interval 0.37 to 0.72, seven studies, I2=20%, τ2=0.0224) and taste (0.31, 0.13 to 0.72, seven studies, I2=78%, τ2=0.5121) than men, and patients with greater initial severity of dysfunction (0.48, 0.31 to 0.73, five studies, I2=10%, τ2<0.001) or nasal congestion (0.42, 0.18 to 0.97, three studies, I2=0%, τ2<0.001) were less likely to recover their sense of smell.

CONCLUSIONS

A substantial proportion of patients with covid-19 might develop long lasting change in their sense of smell or taste. This could contribute to the growing burden of long covid.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021283922.

Asian Pacific Society of Cardiology Consensus Statements on the Diagnosis and Management of Obstructive Sleep Apnoea in Patients with Cardiovascular Disease

Obstructive sleep apnoea (OSA) is strongly associated with cardiovascular disease (CVD). However, evidence supporting this association in the Asian population is scarce. Given the differences in the epidemiology of CVD and cardiovascular risk factors, as well as differences in the availability of healthcare resources between Asian and Western countries, an Asian Pacific Society of Cardiology (APSC) working group developed consensus recommendations on the management of OSA in patients with CVD in the Asia-Pacific region. The APSC expert panel reviewed and appraised the available evidence using the Grading of Recommendations Assessment, Development, and Evaluation system. Consensus recommendations were developed and put to an online vote. Consensus was reached when 80% of votes for a given recommendation were in support of ‘agree’ or ‘neutral.’ The resulting statements provide guidance on the assessment and treatment of OSA in patients with CVD in the Asia-Pacific region. The APSC hopes for these recommendations to pave the way for screening, early diagnosis and treatment of OSA in the Asia-Pacific region.

Association of obstructive sleep apnea with thyroid cancer incidence: a systematic review and meta-analysis

PURPOSE

Obstructive sleep apnea (OSA) is a postulated carcinogen based on epidemiological associations with all-cancer incidence and non-thyroid biological models. However, associations with thyroid carcinoma are unclear.

METHODS

We included observational/randomized studies of associations of OSA with thyroid carcinoma incidence/mortality in adults, from four databases. Random-effects meta-analyses and the population attributable fraction (PAF; from published global OSA prevalence estimates) were computed.

RESULTS

We included four observational studies (N = 2,839,325), all with moderate/low risk of bias. OSA diagnosis was associated with twofold incidence of thyroid carcinoma (pooled HR 2.32, 95% CI 1.35-3.98, I² = 95%), after multi-adjustment for demographics, BMI, smoking, alcohol, and comorbidities. Subgroup analysis of studies with at least 5 years of follow-up showed a stronger association of OSA with thyroid cancer incidence (pooled HR 3.27, 95% CI 2.80-3.82, I² = 0%). Up to 14.5% (95% CI 4.29-27.6%) of incident thyroid carcinomas globally may be associated with OSA. Thyroid carcinoma mortality data was unavailable.

CONCLUSIONS

OSA is associated with higher thyroid carcinoma incidence, though this does not prove causation. Biological/clinical studies should investigate OSA severity in relation to thyroid carcinoma progression and mortality, stratified by tumor histology.

Association of obstructive sleep apnea and nocturnal hypoxemia with all-cancer incidence and mortality: a systematic review and meta-analysis

STUDY OBJECTIVES

Biological models suggest that obstructive sleep apnea (OSA) is potentially carcinogenic. We aimed to clarify the inconsistent epidemiological literature by considering various traditional and novel OSA severity indices.

METHODS

We systematically searched PubMed, Embase, Scopus, and the Cochrane Library for observational or randomized studies of associations of OSA, measured by diagnostic codes or any index, each with all-cancer incidence or mortality in adults, compared with participants with no/mild OSA. Two reviewers independently selected studies, extracted data, and evaluated study bias using the Newcastle-Ottawa scale and quality of evidence using GRADE (Grading of Recommendations Assessment, Development, and Evaluation). We performed inverse variance-weighted, random-effects meta-analyses and sensitivity analyses.

RESULTS

We included 20 observational studies (5,340,965 participants), all with moderate/low bias, from 1,698 records. Based on T90 (sleep duration with oxygen saturation < 90%), patients with OSA who had moderate (T90 > 1.2%, hazard ratio [HR] = 1.28, 95% confidence interval [CI] = 1.07-1.54) and severe nocturnal hypoxemia (T90 > 12%, HR = 1.43, 95% CI = 1.16-1.76) experienced 30%-40% higher pooled all-cancer risk than normoxemic patients, after multiple adjustment for covariates including obesity. Furthermore, severe nocturnal hypoxemia nearly tripled all-cancer mortality (HR = 2.66, 95% CI = 1.21-5.85). Patients with apnea-hypopnea index-defined severe OSA, but not moderate OSA, had higher all-cancer risk (HR = 1.18, 95% CI = 1.03-1.35) but similar all-cancer mortality as patients without OSA. An OSA diagnosis was not associated with all-cancer risk. Evidence quality ranged from low to moderate. Insufficient evidence was available on the oxygen desaturation index, lowest/median saturation, and arousal index.

CONCLUSIONS

In patients with OSA, nocturnal hypoxemia is independently associated with all-cancer risk and mortality. Future studies should explore if risk differs by cancer type, and whether cancer screening and OSA treatment are beneficial.

SYSTEMATIC REVIEW REGISTRATION

Registry: PROSPERO; URL: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=220836; Identifier: CRD42021220836.

CITATION

Tan BKJ, Teo YH, Tan NKW, et al. Association of obstructive sleep apnea and nocturnal hypoxemia with all-cancer incidence and mortality: a systematic review and meta-analysis. J Clin Sleep Med. 2022;18(5):1427-1440.

Neuroradiological Basis of COVID-19 Olfactory Dysfunction: A Systematic Review and Meta-Analysis

Objective

Olfactory dysfunction (OD) is a common presenting symptom of COVID‐19 infection. Radiological imaging of the olfactory structures in patients with COVID‐19 and OD can potentially shed light on its pathogenesis, and guide clinicians in prognostication and intervention.

Methods

PubMed, Embase, Cochrane, SCOPUS were searched from inception to August 1, 2021. Three reviewers selected observational studies, case series, and case reports reporting radiological changes in the olfactory structures, detected on magnetic resonance imaging, computed tomography, or other imaging modalities, in patients aged ≥18 years with COVID‐19 infection and OD, following preferred reporting items for systematic reviews and meta‐analyses guidelines and a PROSPERO‐registered protocol (CRD42021275211). We described the proportion of radiological outcomes, and used random‐effects meta‐analyses to pool the prevalence of olfactory cleft opacification, olfactory bulb signal abnormalities, and olfactory mucosa abnormalities in patients with and without COVID‐19‐associated OD.

Results

We included 7 case–control studies (N = 353), 11 case series (N = 154), and 12 case reports (N = 12). The pooled prevalence of olfactory cleft opacification in patients with COVID‐19 infection and OD (63%, 95% CI = 0.38–0.82) was significantly higher than that in controls (4%, 95% CI = 0.01–0.13). Conversely, similar proportions of cases and controls demonstrated olfactory bulb signal abnormalities (88% and 94%) and olfactory mucosa abnormalities (2% and 0%). Descriptive analysis found that 55.6% and 43.5% of patients with COVID‐19 infection and OD had morphological abnormalities of the olfactory bulb and olfactory nerve, respectively, while 60.0% had abnormal olfactory bulb volumes.

Conclusion

Our findings implicate a conductive mechanism of OD, localized to the olfactory cleft, in approximately half of the affected COVID‐19 patients. Laryngoscope, 132:1260–1274, 2022

The Association of Obstructive Sleep Apnea With Breast Cancer Incidence and Mortality: A Systematic Review and Meta-analysis

Purpose

Emerging evidence from animal models suggests that intermittent hypoxia due to obstructive sleep apnea (OSA) is a risk factor for breast cancer. Despite their biological plausibility, human epidemiological studies have reported conflicting results. Therefore, we conducted a meta-analysis to delineate this relationship.

Methods

We searched the PubMed, Embase, Scopus, and Cochrane Library databases for eligible studies from inception until June 6, 2021. Two reviewers selected randomized trials or observational studies reporting the association between OSA and breast cancer incidence compared with those without OSA. Two reviewers extracted relevant data and assessed the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework and Newcastle-Ottawa Scale (NOS). We pooled the maximally covariate-adjusted hazard ratios (HRs) using a random-effects inverse variance-weighted meta-analysis and performed pre-specified subgroup analyses.

Results

We included six studies out of 1,707 records, comprising a combined cohort of 5,165,200 patients. All studies used the International Classification of Diseases codes to classify OSA and breast cancer. OSA patients had a 36% increased breast cancer risk (HR, 1.36; 95% confidence interval [CI], 1.03–1.80; N = 6, I² = 96%) compared to those without OSA. Most studies adjusted for confounders, such as age, sex, obesity, diabetes mellitus, alcohol use, and hypertension. Subgroup analyses for studies with (1) multivariate adjustment and (2) at least five years of follow-up yielded HRs of 1.35 (95% CI, 0.98–1.87; N = 5, I² = 96%) and 1.57 (95% CI, 1.14–2.18; N = 4; I² = 90%), respectively. One Mendelian randomization study suggested a causal relationship, with a two-fold increase in the odds of breast cancer in patients with OSA.

Conclusion

This meta-analysis suggested that OSA is a risk factor for breast cancer. Future studies should explore the dose-response relationship between OSA and breast cancer, and whether treatment may mitigate breast cancer risk or progression.

The association of obstructive sleep apnea with melanoma incidence and mortality: a meta-analysis of 5,276,451 patients

BACKGROUND

Melanoma is the most aggressive and lethal form of skin cancer. While emerging in-vivo evidence suggests that intermittent hypoxia, a hallmark feature of obstructive sleep apnea (OSA), may induce melanoma tumorigenesis, the epidemiological association between OSA and melanoma has been inconsistent.

METHODS

We performed a literature search of PubMed, Embase, Scopus and Cochrane Library from inception until 6 June 2021. Two reviewers independently selected randomized trials or observational studies that reported the association of OSA with melanoma incidence or mortality in adults, in comparison to participants with no OSA. Two reviewers independently extracted relevant data and assessed the quality of evidence using the GRADE framework and the Newcastle-Ottawa Scale (NOS). We pooled data using an inverse variance-weighted meta-analysis and ran pre-specified subgrourp analyses.

RESULTS

The meta-analysis included six studies out of 1897 records, comprising a combined cohort of 5,276,451 patients. All studies were adjusted for covariates, with majority of studies adjusting for age (N=5) and sex (N = 4). Compared to those without OSA, patients with OSA had 71% higher pooled hazards of melanoma (HR = 1.71; 95% CI: 1.08-2.69, I² = 99%). Subgroup analyses for studies with (1) median follow-up duration of at least five years, (2) prospective study design, (3) adjustment for obesity yielded HRs of 1.88 (95%CI:1.32-2.67, N = 5), 1.11 (95%CI:0.77-1.60, N = 2) and 1.52 (95%CI:0.75-3.08, N = 3) respectively. One study investigating the relationship between OSA and melanoma mortality detected no association. There were insufficient studies to assess publication bias.

CONCLUSIONS

Meta-analysis of mainly retrospective observational studies, with significant heterogeneity, suggests increased melanoma incidence in OSA patients. Future studies should prospectively explore the differential risk of melanoma for varying OSA severity, and whether timely OSA treatment may mitigate this risk.

Design and Multicenter Clinical Validation of a 3-Dimensionally Printed Nasopharyngeal Swab for SARS-CoV-2 Testing

Importance

Three-dimensionally printed nasopharyngeal swabs (3DP swabs) have been used to mitigate swab shortages during the coronavirus disease 2019 (COVID-19) pandemic. Clinical validation for diagnostic accuracy and consistency, as well as patient acceptability, is crucial to evaluate the swab's performance.

Objective

To determine the accuracy and acceptability of the 3DP swab for identifying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Design, Setting, and Participants

A diagnostic study was conducted from May to July 2020 at 2 tertiary care centers in Singapore with different reference swabs (FLOQSwab [COPAN Diagnostics] or Dacron swab [Deltalab]) and swab processing techniques (wet or dry) to evaluate the performance of the 3DP swab compared with traditional, standard-of-care nasopharyngeal swabs used in health care institutions. The participants were patients with COVID-19 in the first 2 weeks of illness and controls with acute respiratory illness with negative test results for SARS-CoV-2. Paired nasopharyngeal swabs were obtained from the same nostril and tested for SARS-CoV-2 by reverse-transcriptase polymerase chain reaction. The sequence of swabs was randomized based on odd and even participant numbers.

Main Outcomes and Measures

Primary outcome measures were overall agreement (OA), positive percentage agreement (PPA), and negative percentage agreement of the 3DP swab compared with reference swabs. Secondary outcome measures were the correlation of cycle threshold (Ct) values of both swabs.

Results

The mean (SD) age of participants was 45.4 (13.1) years, and most participants were men (87 of 89 [97.8%]), in keeping with the epidemiology of the COVID-19 pandemic in Singapore. A total of 79 patients with COVID-19 and 10 controls were recruited. Among the patients with COVID-19, the overall agreement and PPA of the 3DP swab was 91.1% and 93.5%, respectively, compared with reference swabs. The PPA was 100% for patients with COVID-19 who were tested within the first week of illness. All controls tested negative. The reverse-transcriptase polymerase chain reaction Ct values for the ORF1ab and E-gene targets showed a strong correlation (intraclass correlations coefficient, 0.869-0.920) between the 3DP and reference swab on independent testing at each institution despite differences in sample processing. Discordant results for both gene targets were observed only at high Ct values.

Conclusions and Relevance

In this diagnostic study of 79 patients with COVID-19 and 10 controls, the 3DP swab performed accurately and consistently across health care institutions and could help mitigate strained resources in the escalating COVID-19 pandemic.

Prevalence of olfactory and taste dysfunction in COVID-19 patients: a community care facility study

Purpose

We aim to study the prevalence of olfactory and taste dysfunction (OTD) in subjects residing in a Community Care Facility (CCF), a center unique to Singapore that is dedicated to isolate foreign workers with COVID-19 infection who have mild disease with minimal or no symptoms.

Methods

This is a cross-sectional study analyzing data prospectively collected from COVID-19-positive subjects who were admitted into a single-center Singapore EXPO CCF from 1st May 2020 to 1st July 2020. The following variables were collected: age, gender, ethnicity, anosmia, ageusia and acute respiratory infection (ARI) symptoms. Symptoms of anosmia and ageusia were self-declared via a mandatory questionnaire administered on admission.

Results

A total of 1983 subjects were included. The overall prevalence of anosmia and ageusia is 3.0% and 2.6%, respectively. 58% of anosmic subjects have co-existent ageusia and 72.6% of anosmic subjects have no concurrent sinonasal symptoms. OTD is less likely to present in subjects who are asymptomatic for ARI, compared to those symptomatic for ARI (anosmia: 2.0% versus 4.4% p = 0.002; ageusia: 1.6% versus 4.2% p < 0.001). There is a difference in the prevalence of OTD between the different ethnic groups (Indian, Chinese, Bangladeshi and Others), with Chinese and Bangladeshi reporting a higher prevalence (p < 0.043)

Conclusion

The true prevalence of OTD in COVID-19-positive subjects may be low with aggressive screening of all subjects, including those asymptomatic for ARI.

Adaptations of a Tertiary Otorhinolaryngology Head and Neck Surgery Department in Singapore during the COVID-19 Outbreak

PURPOSE

The novel coronavirus 2019 (COVID-19) outbreak which was first reported in Wuhan, China has been declared a pandemic by the World Health Organization on March 11, 2020. Otorhinolaryngologists deal intimately with pathologies of the head and neck region and upper respiratory tract and have been reported as a vulnerable group of healthcare workers who may be more susceptible to COVID-19 nosocomial infection.

METHODS

In this article, we provide a comprehensive overview of the adaptations of Singapore's largest tertiary Otorhinolaryngology department during the COVID-19 outbreak. This was undertaken via an evidence-based approach. The relevant medical literature and evidence underlying our adaptations are highlighted.

RESULTS

A four-pronged strategy including (1) personnel segregation, (2) triaging and decantment, (3) use of personal protective equipment and (4) changes in clinical practice was employed. The strategy was bolstered by drawing upon a collective learnt experience from the 2003 Severe Acute Respiratory Syndrome (SARS) outbreak.

CONCLUSION

A rigorous framework which can preserve operationality while navigating the heightened risks during this outbreak is critical for every Otorhinolaryngology department. As the pandemic continues to evolve and more scientific reports of this disease are made available, approaches will need to be morphed.

The accuracy of healthcare worker versus self collected (2-in-1) Oropharyngeal and Bilateral Mid-Turbinate (OPMT) swabs and saliva samples for SARS-CoV-2

BACKGROUND

Self-sampling for SARS-CoV-2 would significantly raise testing capacity and reduce healthcare worker (HCW) exposure to infectious droplets personal, and protective equipment (PPE) use.

METHODS

We conducted a diagnostic accuracy study where subjects with a confirmed diagnosis of COVID-19 (n = 401) and healthy volunteers (n = 100) were asked to self-swab from their oropharynx and mid-turbinate (OPMT), and self-collect saliva. The results of these samples were compared to an OPMT performed by a HCW in the same patient at the same session.

RESULTS

In subjects confirmed to have COVID-19, the sensitivities of the HCW-swab, self-swab, saliva, and combined self-swab plus saliva samples were 82.8%, 75.1%, 74.3% and 86.5% respectively. All samples obtained from healthy volunteers were tested negative. Compared to HCW-swab, the sensitivities of a self-swab sample and saliva sample were inferior by 8.7% (95%CI: 2.4% to 15.0%, p = 0.006) and 9.5% (95%CI: 3.1% to 15.8%, p = 0.003) respectively. The combined detection rate of self-swab and saliva had a sensitivity of 2.7% (95%CI: -2.6% to 8.0%, p = 0.321). The sensitivity of both the self-collection methods are higher when the Ct value of the HCW swab is less than 30. The specificity of both the self-swab and saliva testing was 100% (95% CI 96.4% to 100%).

CONCLUSION

Our study provides evidence that sensitivities of self-collected OPMT swab and saliva samples were inferior to a HCW swab, but they could still be useful testing tools in the appropriate clinical settings.

Hyoid expansion with titanium plate and screws with hyomandibular suspension: A study on human cadavers with computed tomographic comparative analysis

OBJECTIVES

Obstructive sleep apnoea is characterized by repetitive obstruction of the upper airway during sleep. These repeated oxygen desaturations increase cardiovascular and cerebrovascular morbidity and mortality significantly. Upper airway surgery is an option for patients who fail continuous positive airway pressure therapy. Airway collapse is usually multilevel and hypopharyngeal collapse is a challenging area to address. It is hypothesized that hyoid expansion with hyomandibular suspension can potentially increase upper airway dimensions at the hypopharynx. This study aims to document the effect of hyoid expansion using titanium plate and screws with hyomandibular suspension on hypopharyngeal airway dimensions. It is an anatomical feasibility study performed using 10 human cadaver heads.

METHODS

The hyoid bone is trifractured. The expanded hyoid is then suspended to the mandible. Computed tomography (CT) scans were performed on the cadavers to measure the airway dimensions before and after the procedure.

RESULTS

This procedure resulted in statistically significant increase in airway dimensions at the level of the hypopharynx in all 10 human cadaver heads. Increase in cross-sectional area correlated significantly with increase in 3-dimentional (3D) volume.The mean area of the airway at the level of the hyoid increased from 999.3 ± 193.0 mm2 to 1241.4 ± 103.2 mm2. Statistically significant increase in upper airway volume based on 3D reconstruction was also noted. Upper airway volume increased from 6.94 ± 6.46 mL to 13.58 ± 8.29 mL.

CONCLUSION

Airway dimensions increased with hyoid expansion and hyomandibular suspension in our cadaveric study measured using CT scans. Further studies are needed to see if this technique can be translated to clinical use in live patients.

LEVEL OF EVIDENCE

NA.

Sleep medicine in otolaryngology units: an international survey

PURPOSE

No study to date has described the overall landscape of sleep disorders management and training in otolaryngology departments of different countries. The aim of our study was to investigate and compare settings, diagnostic and therapeutic approaches and training programmes.

METHODS

An international online survey was developed with the collaboration of the YO-IFOS (Young Otolaryngologists-International Federation of Otorhinolaryngological Societies) to assess the current practice of otolaryngologists in the management of sleep disorders. The survey also included a session dedicated to training.

RESULTS

A total of 126 otolaryngologists completed the survey. The larger part of responses was collected from Central/South America and Europe. The majority of responders from South/Central America (97%) declared to be certified as sleep specialist while 49% of Europeans stated the opposite. Of responders 83% perform a drug-induced sleep endoscopy (DISE) before planning a possible surgical intervention. Soft palate and base of tongue interventions were the most common procedure, respectively performed in 94% and 79% of the cases. Residents were allowed to perform soft palate surgery in 77% of the cases. Upper airway stimulation (26% vs 10%), trans-oral robotic surgery (36% vs 11%) and radiofrequency of the base of the tongue (58% vs 25%) were preferred more frequently by European responders. The highest caseloads of soft palate surgery and bi-maxillary advancement were registered in the academic institutions.

CONCLUSION

Significant concordance and few interesting divergences in diagnosis and treatment of sleep disorders were observed between nationalities and types of institution. Economic resources might have played a significant role in the therapeutic choice. Trainees' lack of exposure to certain interventions and to a sufficient caseload appeared to be the main burden to overcome.

The Emerging Role of Drug-Induced Sleep Endoscopy in the Management of Obstructive Sleep Apnea

Obstructive sleep apnea is a prevalent sleep disorder characterized by partial or complete obstruction of the upper airway. Continuous positive airway pressure is the first-line therapy for most patients, but adherence is often poor. Alternative treatment options such as mandibular advancement devices, positional therapy, and surgical interventions including upper airway stimulation target different levels and patterns of obstruction with varying degrees of success. Drug-induced sleep endoscopy enables the visualization of upper airway obstruction under conditions mimicking sleep. In the era of precision medicine, this additional information may facilitate better decision-making when prescribing alternative treatment modalities, with the hope of achieving better adherence and/or success rates. This review discusses the current knowledge and evidence on the role of drug-induced sleep endoscopy in the non-positive airway pressure management of obstructive sleep apnea.

Respiratory droplet generation and dispersal during nasoendoscopy and upper respiratory swab testing

Respiratory particle generation and dispersal during nasoendoscopy and swab testing is studied with high‐speed video and laser light illumination. Video analysis reveals droplet formation in three manoeuvres during nasoendoscopy ‐ sneezing, vocalization, and nasal decongestion spray. A capillary bridge of mucus can be seen when a nasoendoscope exits wet nares. No droplet formation is seen during oral and nasopharyngeal swab testing. We outline the following recommendations: pull the face mask down partially and keep the mouth covered, only allowing nasal access during nasoendoscopy; avoid nasal sprays if possible; if nasal sprays are used, procedurists should be in full personal protective equipment prior to using the spray; withdrawal of swabs and scopes should be performed in a slow and controlled fashion to reduce potential dispersion of droplets when the capillary bridge of mucus breaks up.

Respiratory sampling for severe acute respiratory syndrome coronavirus 2: An Overview

The novel coronavirus disease 2019 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and was declared a pandemic in March 2020. A plethora of respiratory sampling methods for SARS-CoV-2 viral detection has been used and in the current evolving situation, there is no international consensus on the recommended method of respiratory sampling for diagnosis. Otolaryngologists deal intimately with the upper respiratory tract and a clear understanding of the respiratory sampling methods is of paramount importance. This article aims to provide an overview of the various methods and their evidence till date.

Evaluation of prefabricated adjustable thermoplastic mandibular advancement devices (PAT-MADs) for obstructive sleep apnea: an Asian experience

OBJECTIVE

To evaluate the use of direct to consumer Prefabricated adjustable thermoplastic mandibular advancement devices (PAT-MADs) (MyTAP™, Airway Management Inc), its effectiveness in the treatment of OSA, feasibility and short-term adherence.

METHODS

In sum, 50 patients with diagnosed mild-moderate OSA on formal polysomnography (PSG) were fitted with a PAT-MAD (MyTAP™, Airway Management Inc). Sleep indices included the apnea-hypopnea index (AHI), hypopnea index (HI), apnea index (AI); oxygen desaturation index (ODI), and the lowest 0₂ saturation (Lsat) were measured with a Level 3 home sleep apnea test (HSAT) pre versus post treatment. Quality of life (QOL) surveys of Epworth sleepiness scale (ESS), Pittsburg sleep quality index (PSQI), Functional outcomes of sleep quality-10 (FOSQ10) and satisfaction surveys were administered.

RESULTS

Over three months, indices showed a trend towards improvement. Results were statistically significant when stratified into groups who achieved cure and success. Moreover, there was a mean improvement in AHI: -12.7 ± 9.3, AI: -5.7 ± 8.2, HI: -6.3 ± 3.7, ODI: -11.2 ± 8.6 for responders with a success rate of 41%. Out of QOL surveys, ESS showed a decrease of -1.41 [-2.52, -0.3] (p = 0.017) when controlled for age and body mass index (BMI). Up to 68.8% of patients found that the device was useful in alleviating snore symptoms. Adherence rate was reported at 59%.

CONCLUSION

Titratable PAT-MAD is an economical and effective option for a patient of Chinese descent. It has the potential to serve as a device for trial use and means of selection before proceeding with customized MADs. Further studies will be required to substantiate other factors which influence the recommendation of MADs for patients with this demographic.

Holistic Management of Obstructive Sleep Apnea: Translating Academic Research to Patient Care

A holistic approach is pertinent in managing obstructive sleep apnea (OSA). It goes beyond integrated multidisciplinary assessment and management in the hospital setting. Although clinicians should be aware of different treatment modalities and adjunctive measures, proactive management of OSA is as important. The future of OSA management lies in identifying patients at risk of developing OSA and developing strategy to prevent OSA from taking root. It involves active screening of patients with OSA and treating them and identifying patients with OSA with high risk of preventable serious morbidity and death and intervening early to prevent these from happening.

Choosing the right mask for your Asian patient with sleep apnoea: A randomized, crossover trial of CPAP interfaces

BACKGROUND AND OBJECTIVE

A major challenge with the treatment of obstructive sleep apnoea (OSA) is adherence to continuous positive airway pressure (CPAP) therapy. Mask tolerability is an important determinant of adherence, however evidence to guide selection of mask interfaces is lacking.

METHODS

We conducted a randomized crossover trial of mask interfaces in CPAP therapy for moderate-to-severe OSA to assess adherence and efficacy of CPAP therapy with nasal mask, nasal pillow and oronasal masks. Demographic data, Nasal Obstruction Symptom Evaluation (NOSE) scores and craniofacial measurements were also analysed for associations with adherence with oronasal masks.

RESULTS

Eighty-five patients were included in the study (mean ± SD age: 46 ± 12 years; body mass index: 29.9 ± 5.6 kg/m² ; apnoea-hypopnoea index (AHI): 53.6 ± 24.0 events/h). Patients had better adherence with nasal masks (average night use: 3.96 ± 2.26 h/night) compared to oronasal masks (3.26 ± 2.18 h/night, P < 0.001) and nasal pillows (3.48 ± 2.20 h/night, P = 0.007). Residual AHI was higher with oronasal masks (7.2 ± 5.2) compared to nasal masks (4.0 ± 4.2, P < 0.001) and nasal pillows (4.1 ± 3.3, P < 0.001). Twenty-two (25.9%) patients had the best adherence with oronasal masks (4.22 ± 2.14 vs 2.93 ± 2.12 h/night, P = 0.016). These patients had lower NOSE scores (15 (0-35) vs 40 (10-55), P = 0.024) and larger menton-labrale inferioris/biocular width ratios (31 ± 3% vs 28 ± 4%, P = 0.019).

CONCLUSION

Nasal masks are the preferred interface during CPAP initiation. Patients with less nasal obstruction and a proportionally increased chin-lower lip distance to mid-face width may have better CPAP adherence with an oronasal mask interface.

Apnoeic and Hypopnoeic Load in Obstructive Sleep Apnoea: Correlation with Epworth Sleepiness Scale

INTRODUCTION

Patients with obstructive sleep apnoea (OSA) often present with excessive daytime sleepiness (EDS) as measured by the Epworth Sleepiness Scale (ESS). However, the relationship between EDS and OSA severity as measured by the apnoea-hypopnoea index (AHI) remains inconsistent. We hypothesise that this may be due to the usage and equal weightage of apnoea and hypopnoea events used in determining AHI and that apnoea and hypopnoea load as measured by their total durations may be a better metric to use. We sought to investigate if apnoea or hypopnoea load can display better correlation with ESS.

MATERIALS AND METHODS

Retrospective analysis of 821 patients with AHI ≥5, who underwent in-laboratory polysomnogram for suspected OSA from January 2015-December 2015, was performed. Objective factors on polysomnogram were correlated with ESS.

RESULTS

ESS was correlated with age (r = -0.148, P <0.001), number of apnoeas (r = 0.096, P = 0.006), apnoea load (r = 0.102, P = 0.003), apnoea index (r = 0.075, P = 0.032), number of desaturations (r = 0.081, P = 0.020), minimum SpO₂ (r = -0.071, P = 0.041), time SpO₂ <85% (r = 0.075, P = 0.031) and REM sleep duration (r = 0.099, P = 0.004). Linear regression analysis found age (P <0.001), apnoea load (P = 0.005), REM (P = 0.021) and stage 1 sleep duration (P = 0.042) as independent factors correlated to ESS. The apnoea load calculated using duration in apnoea correlate with ESS in patients with severe OSA by AHI criteria compared to the mild category.

CONCLUSION

AHI does not correlate with ESS. Younger age, longer apnoea, stage 1 and REM sleep were independently related to higher ESS though the correlations were weak. Apnoea load should be taken into account when determining OSA severity.

Complications and Pain in Obstructive Sleep Apnoea - Comparing Single and Multilevel Surgery

INTRODUCTION

This study aimed to investigate differences in the complication rate and postoperative pain score between single and multilevel surgery performed on patients with obstructive sleep apnoea.

MATERIALS AND METHODS

A retrospective analysis was performed on patients with obstructive sleep apnoea who underwent surgery in a tertiary referral centre over 3 years. Patients who underwent single-level nasal, palatal or tongue surgery were compared with patients who underwent concurrent multilevel surgery of 2 or 3 levels. Complications and the postoperative Visual Analogue Scale pain score were recorded and the outcomes between single and multilevel groups were compared.

RESULTS

The overall complication rate for patients was 12.6%, 6.7% if only patients requiring intervention were considered. The adjusted odds ratio (OR) for complication rate for patients undergoing multilevel surgery and single-level surgery was 2.76. It was statistically significant (P=0.053) after adjusting for confounders. There was more pain in patients who underwent multilevel surgery than in the single-level surgery group.

CONCLUSION

Concurrent multilevel surgery is a feasible option in patients with multilevel obstruction, especially if they are undergoing palate and tongue surgery, nose and palate surgery or nose and tongue surgery. There may be more complications, though it is not statistically significant. Further studies are required to investigate the differences between single-level nasal surgery and 3-level multilevel surgery. More patients undergoing multilevel surgery than single-level surgery experienced pain. Multilevel surgery patients should have their analgesia reviewed regularly and titrated accordingly.

Prevalence of Cardiac Arrhythmias in Asian Patients With Obstructive Sleep Apnea: A Singapore Sleep Center Experience

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is associated with increased cardiovascular morbidity and mortality. Cardiac arrhythmias are common in patients with OSA. However, the prevalence and significance of cardiac arrhythmias in Asian patients with OSA are not well studied. The aim of this study is to determine the prevalence of cardiac arrhythmias in patients with OSA in Singapore and to evaluate possible factors that may predispose patients with OSA to arrhythmias.

METHODS

A retrospective study of 2,019 patients was carried out from January 2011 to December 2012 at a sleep center in a tertiary medical center. Of the population, 1,457 patients were found to have OSA and 144 patients were found to have cardiac arrhythmias. Data collected included patient demographics, comorbidities, and polysomnogram parameters.

RESULTS

The prevalence of cardiac arrhythmias in our OSA population is 8.0%, compared to that of primary snorers at 4.8% (P = .015). The univariate analysis revealed that older age, higher body mass index, comorbidities, and severity of OSA, including apnea-hypopnea index (AHI), lowest oxygen saturation (LSAT) and hypoxic time were correlated with a higher prevalence of cardiac arrhythmias (P < .05). However, the multivariate analysis showed that only age and body mass index were significantly correlated with arrhythmias. AHI, LSAT, and hypoxic time were no longer statistically significant.

CONCLUSIONS

Our study demonstrated that cardiac arrhythmias are common in patients with OSA in Singapore. It also suggests that given the different demographics of our population, ethnicity may play a significant role in the development of cardiovascular disease among patients with OSA.

COMMENTARY

A commentary on this article appears in this issue on page 1229.

Robotic Obstructive Sleep Apnea Surgery

Since the first report of the use of the da Vinci robotic system (Intuitive Surgical, Sunnyvale, CA, USA) in transoral robotic tongue base reduction for obstructive sleep apnea (OSA) was published in 2010, this surgical tool and technique has been used worldwide for the resection of tongue base tissue in the multilevel surgical treatment of OSA. The combined knowledge of the published literature on its use has enlightened sleep surgeons worldwide on this new yet evolving surgical tool. Here we will discuss the use of the da Vinci robotic system in the treatment of OSA, the pertinent surgical anatomy for a safe surgical procedure, the primary and secondary outcomes to expect in the multilevel and primary use of this technology in treating the tongue base, the predictors for success or failure, and the complications associated with this technique. We will also compare this technology with other existing techniques for treating OSA and look to the future for other similar technologies in this application.

Quality of Life in Obstructive Sleep Apnoea: A Role for Oxygen Desaturation Indices?

INTRODUCTION

This study aimed to determine the impact of obstructive sleep apnoea (OSA) on quality of life (QOL) and evaluate the utility of polysomnographic parameters in reflecting QOL.

MATERIALS AND METHODS

Eighty-eight patients who underwent polysomnography (PSG) between December 2010 and November 2012 consecutively were recruited and they completed the 36-Item Short-Form Health Survey (SF-36) and Epworth Sleepiness Scale (ESS) questionnaires. Based on the apnoea-hypopnoea index (AHI), patients were classified as primary snorers (AHI <5), suffering from mild (5 ≤15), moderate (15 ≤30) or severe OSA (≥30).

RESULTS

Seventy-nine male and 9 female patients with a mean age of 41 years were recruited. OSA patients scored significantly lower on 7 domains of SF-36 compared to the population. As AHI increased, only Physical Function (PF) and Physical Component Summary (PCS) but not ESS scores significantly worsened. PSG parameters correlated poorly with all QOL measures except PF, PCS and ESS. After adjusting for age, sex and body mass index (BMI), multiple linear regression revealed that only the oxygen desaturation parameters, but not sleep architecture indices or AHI were significant predictors of PF and ESS. For every fall in the lowest oxygen saturation (LSAT) by 1%, there was a decrease in PF by 0.59 points, and an increase in ESS by 0.13 points.

CONCLUSION

OSA patients have a poor QOL compared to the population. The amount of physical impairment and daytime sleepiness they experience is better predicted by severity and duration of hypoxia and not AHI.

State of the art transoral robotic surgery for obstructive sleep apnea-hypopnea syndrome

Objective

To review the existing literature on the role of transoral robotic surgery (TORS) for tongue base reduction in the management of adult obstructive sleep apnea-hypopnea syndrome (OSAHS).

Methods

We searched PubMed, MEDLINE, and Scopus databases from the first literature report of this surgical technique to July 30, 2015 for studies investigating the use of TORS for tongue base reduction in treating adult OSAHS. Our primary outcome measures were Apnea– Hypopnea Index (AHI), lowest oxygen saturation (LSAT), Epworth Sleepiness Score (ESS), and the rates of surgical cure (AHI<5) and success (50% reduction in AHI accompanied by a postoperative AHI<20). Our secondary outcome measures were the volume of tissue resected and correlation to AHI, polysomnographic parameters, subjective outcomes, and body mass index. Complications of surgery were also analyzed.

Results

Thirteen articles were critically evaluated for this research. However, only four case series qualified for statistical analysis of postoperative polysomnographic outcomes and six case series for analysis of postoperative complications. They were case series with a total of 451 adult patients. Pooled analysis revealed statistically significant improvements in AHI, LSAT, and ESS after surgery by 26.83/hour, 5.28% and −8.03, respectively. The average rates of surgical cure and success were 23.8% and 66.7%, respectively. No study reported any deaths or complications related to the use of robotic equipment. The major complication rate was 6.9%, and the minor complication rate was 30.0%. Major complications included major bleeding (2.9%), severe odynophagia with dehydration (3.3%), and oropharyngeal stenosis (0.7%). Minor complications included transient bleeding (0.5%), transient dysphagia (3.8%), and dysgeusia (6.6%).

Conclusion

TORS for tongue base reduction, as a component of multilevel surgery, is an effective treatment option for OSAHS with an acceptable morbidity. This conclusion is based on the analysis of the results of multiple case series. Future studies should entail prospective randomized controlled trials with larger sample size for longer follow-up period.

A Cost-Effectiveness Analysis of Surgery for Middle-Aged Men with Severe Obstructive Sleep Apnea Intolerant of CPAP

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is associated with increased cardiovascular morbidity and mortality. Conventional OSA therapy necessitates indefinite continuous positive airway pressure (CPAP). Although CPAP is an effective treatment modality, up to 50% of OSA patients are intolerant of CPAP. We explore whether surgical modalities developed for those intolerant of CPAP are cost-effective.

METHODS

We construct a lifetime semi-Markov model of OSA that accounts for observed increased risks of stroke, cardiovascular disease, and motor vehicle collisions for a 50-year-old male with untreated severe OSA. Using this model, we compare the cost-effectiveness of (1) no treatment, (2) CPAP only, and (3) CPAP followed by surgery (either palatopharyngeal reconstructive surgery [PPRS] or multilevel surgery [MLS]) for those intolerant to CPAP.

RESULTS

Compared with the CPAP only strategy, CPAP followed by PPRS (CPAP-PPRS) adds 0.265 quality adjusted life years (QALYs) for an increase of $2,767 (discounted 2010 dollars) and is highly cost effective with an incremental cost-effectiveness ratio (ICER) of $10,421/QALY for a 50-year-old male with severe OSA. Compared to a CPAP-PPRS strategy, the CPAP-MLS strategy adds 0.07 QALYs at an increase of $6,213 for an ICER of $84,199/QALY. The CPAP-PPRS strategy appears cost-effective over a wide range of parameter estimates.

CONCLUSIONS

Palatopharyngeal reconstructive surgery appears cost-effective in middle-aged men with severe OSA intolerant of CPAP. Further research is warranted to better define surgical candidacy as well as short-term and long-term surgical outcomes.

COMMENTARY

A commentary on this article appears in this issue on page 509.

Postoperative Complications in Obstructive Sleep Apnea Patients: A Comparison between Single and Multilevel Surgery

Objectives:

Evaluate the difference in the postoperative complication rate between single and multilevel surgery performed on patients with obstructive sleep apnea (OSA).

Methods:

A retrospective outcomes analysis was performed on 238 patients with OSA who underwent surgery from January 2011 to December 2013 under the care of the third author in a tertiary referral center. Complications were defined as unexpected events needing additional medical attention within 30 days of surgery. These included but were not limited to: emergency department visits, nasal packing, cautery in the outpatient setting, hospitalization, and need for return to the operating room. Early complications were those occurring within the first 24 hours of surgery while late complications were defined as those occurring after 24 hours.

Results:

Of 238 patients, 88 underwent single level surgery and 150 underwent multilevel surgery. There were none lost to follow-up. The main complication was bleeding. The complication rate was 5.7% in the single level group and 14.7% in the multilevel group. The difference in complication rate was significant, with P < .05. The confidence interval was from 1.04 to 7.83 and the odds ratio was 2.85.

Conclusions:

There is an overall higher complication rate in obstructive sleep apnea patients undergoing multilevel surgery. However, the overall risk remains low and most complications are minor. This reminds us to be cautious in the management of such patients, especially if they have had multiple procedures performed.

Evaluation of recurrent nodal disease after definitive radiation therapy for nasopharyngeal carcinoma: Diagnostic value of fine-needle aspiration cytology and CT scan

BACKGROUND

Recurrent nodal disease in patients with nasopharyngeal carcinoma (NPC) after definitive radiotherapy presents a difficult clinical problem. This cohort of patients poses a diagnostic challenge to the head and neck surgeon because evaluation of the post-irradiated neck, both clinically and radiologically, is known to be difficult, and it is not uncommon for neck dissection specimen in suspected recurrent nodal disease to contain no viable tumor cells. Currently, there is no well-accepted method for the preoperative determination of the presence of malignancy in these nodal diseases.

METHODS

Over a 7-year period in a tertiary hospital, we systematically reviewed the clinical charts of 42 patients with NPC who were diagnosed with suspected recurrent nodal disease, after radical definitive radiotherapy. Fine-needle aspiration cytology (FNAC) was performed on clinically palpable nodes and results were correlated with final histopathologic results. Findings on CT scan were also correlated with final histopathologic specimens.

RESULTS

The specificity and sensitivity of FNAC was 75.0% and 75.0%, respectively. The positive and negative predictive value of FNAC was 93.8% and 37.5%, respectively. CT scan had a positive predictive value of 78.6%. The negative predictive value for multilevel involvement on CT scan was 20%.

CONCLUSION

Radiological imaging and FNAC are useful diagnostic modalities in assessing recurrent nodal disease in the post-irradiated neck in patients with NPC. Although routine CT scan criteria for pathologic lymphadenopathy cannot be accurately applied in the post-irradiated neck, it is a useful surveillance tool in the routine follow-up of patients with post-irradiated neck with NPC. Clinicians, however, must understand their limitations when assessing these patients. The possibility of negative neck dissection must be conveyed to the patients.

Sensorineural hearing loss after radiotherapy and chemoradiotherapy: a single, blinded, randomized study

PURPOSE

The synergistic ototoxicity of radiation and cisplatin (CDDP) has not been adequately studied. This study investigated whether the use of concurrent and postradiotherapy CDDP in patients with nasopharyngeal carcinoma (NPC) resulted in a difference in postradiotherapy sensorineural hearing when compared with the use of radiotherapy alone.

PATIENTS AND METHODS

Newly diagnosed patients were randomly assigned to the radiotherapy or chemoradiotherapy groups. Bone conduction hearing thresholds were performed before treatment and at 1 week, 6 months, 1 year, and 2 years after completion of radiotherapy. Statistical analysis was performed using the Mann-Whitney U test.

RESULTS

Hearing thresholds averaged over 0.5, 1, and 2 kHz were found to be poorer in the chemoradiotherapy group (58 patients) compared with the radiotherapy group (57 patients) at 1 year (P = .001) and 2 years (P = .03) after radiotherapy. Hearing thresholds at 4 kHz were significantly worse for patients in the chemoradiotherapy arm at all of the postradiotherapy time points studied and were more severely affected than the thresholds at lower speech frequencies. In the radiotherapy group, deterioration of median hearing thresholds, which occurred in the immediate post-treatment period, improved within the first year but deteriorated again at 2 years. In the chemoradiotherapy group, median hearing threshold deterioration, which started immediately after radiotherapy, stabilized by 1 year.

CONCLUSION

Patients with NPC who received radiotherapy and concurrent/adjuvant chemotherapy using CDDP experienced greater sensorineural hearing loss compared with patients treated with radiotherapy alone, especially to high-frequency sounds in the speech range. Normal inner ear tissue tolerance, which was once defined only for radiotherapy patients alone, should be redefined in chemoradiotherapy patients.