Obstructive sleep apnoea syndrome: translating science to clinical practice

Sleep-disordered breathing and malocclusion in children and adolescents-a systematic review

BACKGROUND

Sleep-disordered breathing (SDB) has negative influence on children's development and well-being. Malocclusion due to some craniofacial anatomical characteristics may be associated with SDB.

OBJECTIVES

The aim of this paper is to ascertain whether SDB is associated with malocclusion in children/adolescents, aged 6-15 years compared to healthy controls.

METHODS

Prospero ID: CRD42021232103. A systematic electronic literature search following PRISMA was performed in PubMed, Embase and Cochrane Library. Inclusion criteria were as follows: Healthy children/adolescents aged 6-15 years with malocclusion undergoing polysomnography (PSG) or polygraphy (PG) and/or sleep questionnaire and orthodontic screening; compared to a healthy age-matched control group with neutral or minor deviation in the occlusion without requirement for orthodontic treatment; publications in English, Danish, Norwegian or Swedish published until 23 March 2021. JBI Critical Appraisal Tools and GRADE were used to evaluate the risk of bias and level of evidence.

RESULTS

The search resulted in 1996 records, 610 duplicates were removed, 1386 records were screened, and 1322 records were excluded. Sixty-four studies were selected for full-text reading, and four publications fulfilled the inclusion criteria. The included studies had moderate risk of bias, and the quality of evidence was low.

CONCLUSION

No firm conclusion can be drawn regarding an association between specific malocclusion traits and SDB. Thus, the studies found no association between molar relationship and crowding and SDB symptoms in children. It may be recommended that future studies include objective PSG or PG in diagnosis of SDB and compare groups of children with skeletal malocclusion and controls with neutral malocclusion.

Examination of the diaphragm in obstructive sleep apnea using ultrasound imaging

PURPOSE

The aim of this study was to analyze the effect of obstructive sleep apnea (OSA) on the ultrasound (US) features of the diaphragm and to determine if diaphragmatic US may be a useful screening tool for patients with possible OSA.

METHODS

Patients complaining of snoring were prospectively enrolled for overnight polygraphy using the ApneaLink Air device. Thickness and motion of the diaphragm during tidal and deep inspiration were measured. Logistic regression was used to assess parameters of the diaphragm associated with OSA.

RESULTS

Of 100 patients, 64 were defined as having OSA. Thicknesses of the left and right hemidiaphragms were significantly different between OSA and control groups. Using a combination of diaphragmatic dimensions, diaphragm dilation, age, sex, and BMI, we developed an algorithm that predicted the presence of OSA with 91% sensitivity and 81% specificity.

CONCLUSION

A combination of anthropometric measurements, demographic factors, and US imaging may be useful for screening patients for possible OSA. These findings need to be confirmed in larger sample sizes in different clinical settings.

Society of Anesthesia and Sleep Medicine Guideline on Intraoperative Management of Adult Patients With Obstructive Sleep Apnea

The purpose of the Society of Anesthesia and Sleep Medicine Guideline on Intraoperative Management of Adult Patients With Obstructive Sleep Apnea (OSA) is to present recommendations based on current scientific evidence. This guideline seeks to address questions regarding the intraoperative care of patients with OSA, including airway management, anesthetic drug and agent effects, and choice of anesthesia type. Given the paucity of high-quality studies with regard to study design and execution in this perioperative field, recommendations were to a large part developed by subject-matter experts through consensus processes, taking into account the current scientific knowledge base and quality of evidence. This guideline may not be suitable for all clinical settings and patients and is not intended to define standards of care or absolute requirements for patient care; thus, assessment of appropriateness should be made on an individualized basis. Adherence to this guideline cannot guarantee successful outcomes, but recommendations should rather aid health care professionals and institutions to formulate plans and develop protocols for the improvement of the perioperative care of patients with OSA, considering patient-related factors, interventions, and resource availability. Given the groundwork of a comprehensive systematic literature review, these recommendations reflect the current state of knowledge and its interpretation by a group of experts at the time of publication. While periodic reevaluations of literature are needed, novel scientific evidence between updates should be taken into account. Deviations in practice from the guideline may be justifiable and should not be interpreted as a basis for claims of negligence.

Obstructive sleep apnoea in adults: peri-operative considerations: A narrative review

: Obstructive sleep apnoea (OSA) is a common breathing disorder of sleep with a prevalence increasing in parallel with the worldwide rise in obesity. Alterations in sleep duration and architecture, hypersomnolence, abnormal gas exchange and also associated comorbidities may all feature in affected patients.The peri-operative period poses a special challenge for surgical patients with OSA who are often undiagnosed, and are at an increased risk for complications including pulmonary and cardiovascular, during that time. In order to ensure the best peri-operative management, anaesthetists caring for these patients should have a thorough understanding of the disorder, and be aware of the individual's peri-operative risk constellation, which depends on the severity and phenotype of OSA, the invasiveness of the surgical procedure, anaesthesia and also the requirement for postoperative opioids.The objective of this review is to educate clinicians in the epidemiology, pathogenesis and diagnosis of OSA in adults and also to highlight specific tasks in the preoperative assessment, namely to select a suitable intra-operative anaesthesia regimen, and manage the extent and duration of postoperative care to facilitate the best peri-operative outcome.

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

BACKGROUND

Emerging evidence associating obstructive sleep apnea (OSA) with adverse perioperative outcomes has recently heightened the level of awareness among perioperative physicians. In particular, estimates projecting the high prevalence of this condition in the surgical population highlight the necessity of the development and adherence to "best clinical practices." In this context, a number of expert panels have generated recommendations in an effort to provide guidance for perioperative decision-making. However, given the paucity of insights into the status of the implementation of recommended practices on a national level, we sought to investigate current utilization, trends, and the penetration of OSA care-related interventions in the perioperative management of patients undergoing lower joint arthroplasties.

METHODS

In this population-based analysis, we identified 1,107,438 (Premier Perspective database; 2006-2013) cases of total hip and knee arthroplasties and investigated utilization and temporal trends in the perioperative use of regional anesthetic techniques, blood oxygen saturation monitoring (oximetry), supplemental oxygen administration, positive airway pressure therapy, advanced monitoring environments, and opioid prescription among patients with and without OSA.

RESULTS

The utilization of regional anesthetic techniques did not differ by OSA status and overall <25% and 15% received neuraxial anesthesia and peripheral nerve blocks, respectively. Trend analysis showed a significant increase in peripheral nerve block use by >50% and a concurrent decrease in opioid prescription. Interestingly, while the absolute number of patients with OSA receiving perioperative oximetry, supplemental oxygen, and positive airway pressure therapy significantly increased over time, the proportional use significantly decreased by approximately 28%, 36%, and 14%, respectively. A shift from utilization of intensive care to telemetry and stepdown units was seen.

CONCLUSIONS

On a population-based level, the implementation of OSA-targeted interventions seems to be limited with some of the current trends virtually in contrast to practice guidelines. Reasons for these findings need to be further elucidated, but observations of a dramatic increase in absolute utilization with a proportional decrease may suggest possible resource constraints as a contributor.

Obesity and sleep-disordered breathing--when two 'bad guys' meet

Sleep-disordered breathing (SDB), in particular obstructive sleep apnoea (OSA) and obesity hypoventilation syndrome (OHS) are associated with significant morbidity and mortality. The prevalence of these conditions is rapidly rising mainly due to the worldwide increase in obesity. Obesity contributes to the pathogenesis of SDB in multiple ways including altering upper airway anatomy and collapsibility, ventilatory control and increasing respiratory work load. There is also increasing evidence that OSA itself contributes to the development of obesity. Moreover, both OSA and obesity promote the activation of inflammatory pathways, which is likely a key mechanism in cardiovascular and metabolic disease processes. Early recognition of SDB is important as effective treatments are available. Public health measures to reduce the prevalence of obesity are urgently required to halt the increasing burden of SDB.

Adverse respiratory events after general anesthesia in patients at high risk of obstructive sleep apnea syndrome

INTRODUCTION

Patients with STOP-BANG score >3 have a high risk of Obstructive sleep apnea. The aim of this study was to evaluate early postoperative respiratory complications in adults with STOP-BANG score >3 after general anesthesia.

METHODS

This is a prospective double cohort study matching 59 pairs of adult patients with STOP-BANG score >3 (high risk of obstructive sleep apnea) and patients with STOP-BANG score <3 (low risk of obstructive sleep apnea), similar with respect to gender, age and type of surgery, admitted after elective surgery in the Post-Anaesthesia Care Unit in May 2011. Primary outcome was the development of adverse respiratory events. Demographics data, perioperative variables, and postoperative length of stay in the Post-Anesthesia Care Unit and in hospital were recorded. The Mann-Whitney test, the chi-square test and the Fisher exact test were used for comparisons.

RESULTS

Subjects in both pairs of study subjects had a median age of 56 years, including 25% males, and 59% were submitted to intra-abdominal surgery. High risk of obstructive sleep apnea patients had a higher median body mass index (31 versus 24kg/m(2), p<0.001) and had more frequently co-morbidities, including hypertension (58% versus 24%, p<0.001), dyslipidemia (46% versus 17%, p<0.001) and insulin-treated diabetes mellitus (17% versus 2%, p=0.004). These patients were submitted more frequently to bariatric surgery (20% versus 2%, p=0.002). Patients with high risk of obstructive sleep apnea had more frequently adverse respiratory events (39% versus 10%, p<0.001), mild to moderate desaturation (15% versus 0%, p=0.001) and inability to breathe deeply (34% versus 9%, p=0.001).

CONCLUSION

After general anesthesia high risk of obstructive sleep apnea patients had an increased incidence of postoperative respiratory complications.

Diaphragm muscle remodeling in a rat model of chronic intermittent hypoxia

Respiratory muscle remodeling occurs in human sleep apnea--a common respiratory disorder characterized by chronic intermittent hypoxia (CIH) due to recurrent apnea during sleep. We sought to determine if CIH causes remodeling in rat sternohyoid (upper airway dilator) and diaphragm muscles. Adult male Wistar rats were exposed to CIH (n=8), consisting of 90 sec of hypoxia (5% at the nadir; SaO₂ ~80%)/90 sec of normoxia, 8 hr per day, for 7 consecutive days. Sham animals (n=8) were exposed to alternating air/air cycles in parallel. The effect of CIH on myosin heavy-chain (MHC) isoform (1, 2a, 2x, 2b) distribution, sarcoplasmic reticulum calcium ATPase (SERCA) isoform distribution, succinate dehydrogenase activity, glycerol phosphate dehydrogenase activity, and Na⁺/K⁺ ATPase pump content was determined. Sternohyoid muscle structure was unaffected by CIH treatment. CIH did not alter oxidative/glycolytic capacity or the Na⁺/K⁺-ATPase pump content of the diaphragm. CIH significantly increased the areal density of MHC 2b fibers in the rat diaphragm, and this was associated with a shift in SERCA proteins from SERCA2 to SERCA1. We conclude that CIH causes a slow-to-fast fiber transition in the rat diaphragm after just 7 days of treatment. Respiratory muscle functional remodeling may drive aberrant functional plasticity such as decreased muscle endurance, which is a feature of human sleep apnea.

Postoperative complications in obstructive sleep apnea

STUDY OBJECTIVES

This study was conducted to determine whether postoperative complications are increased in patients with obstructive sleep apnea (OSA) and to study the impact of the severity of OSA and preoperative use of continuous positive airway pressure (CPAP) on the postoperative outcome.

DESIGN AND SETTING

This study is retrospective in nature and was undertaken at the VA Medical Center.

PARTICIPANTS AND METHODS

Three hundred seventy patients who had undergone both a major surgical procedure and a sleep study from 2000 to 2010 were identified. Patients were divided into four groups: OSA negative (apnea-hypopnea index (AHI) < 5/h), OSA positive; mild: AHI 5 to <15/h; moderate: AHI 15 to <30/h; and severe: AHI ≥ 30/h. No intervention was made during the course of the study. Postoperative complications namely respiratory, cardiac, neurological, and unplanned intensive care unit transfers were collected.

RESULTS

There were 284 (76.8 %) patients having OSA and 86 (23.2 %) without OSA. The overall incidence of total complications was significantly higher in the OSA patients compared with the control patients (48.9 vs. 31.4 %; odds ratio 2.09, 95 % CI 1.25-3.49). There was no significant difference in total complications between those using and not using CPAP prior to hospitalization. Patients with sleep apnea had a higher incidence of respiratory complications compared to patients without sleep apnea (40.4 vs. 23.2 %; odds ratio 2.24, 95 % CI 1.29-3.90). There was no significant difference in major cardiac complications in the OSA patients compared with the control patients (13.0 vs. 9.3 %; odds ratio 1.46, 95 % CI 0.65-3.26).

CONCLUSION

OSA is associated with a significantly increased rate of postoperative complications.

Analgesic properties of a dexmedetomidine infusion after uvulopalatopharyngoplasty in patients with obstructive sleep apnea

Background:

Dexmedetomidine is an alpha₂ -adrenergic agonist with sedative and analgesic properties. This study aimed to investigate if the use of a continuous dexmedetomidine infusion with i.v. morphine patient-controlled analgesia (PCA) could improve postoperative analgesia while reducing opioid consumption and opioid-related side effects.

Methods:

In this prospective randomized, double-blinded, controlled study, 39 patients with obstructive sleep apnea syndrome undergoing uvulopalatopharyngoplasty were assigned to two groups. Group D (dexmedetomidine group) received a loading dose of dexmedetomidine 1 μg.kg^-1 i.v., 30 minutes before the anticipated end of surgery, followed by infusion at 0.6 μg.kg^-1 h^-1 for 24 hours. Group P (placebo group) received a bolus and infusion of placebo. In both groups, postoperative pain was initially controlled by i.v. morphine titration and then PCA with morphine. Cumulative PCA morphine consumption, pain intensities, sedation scores, cardiovascular and respiratory variables and opioid-related adverse effects were recorded for 48 hours after operation.

Results:

Compared with placebo group, patients in the dexmedetomidine group required 52.7% less PCA morphine during the first 24 hours postoperatively, with significantly better visual analogue scale scores, less incidence of respiratory obstruction (5 vs. 12 patients, respectively; P = .037) and longer time to first analgesic request (21 (11) vs. 9 (4) minutes; P = .002). Fewer patients in group D experienced nausea and vomiting than those in group P (7 vs. 24 patients, respectively; P < .05).

Conclusion:

Continuous dexmedetomidine infusion may be a useful analgesic adjuvant for patients susceptible to opioid-induced respiratory depression.

Obstructive sleep apnea: preoperative assessment

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

Meeting the challenge of obstructive sleep apnea: developing a protocol that guides perianesthesia patient care

Caring for a patient postoperatively with a medical history of diagnosed or suspected obstructive sleep apnea (OSA) is not uncommon. OSA is estimated to be present in 2%-26% of the general population, and the National Sleep Foundation proposes that one in four Americans are at high risk for OSA. Also of concern is that the incidence of OSA may increase as our population ages. Despite published guidelines, it can be difficult to implement recommendations that include increased monitoring of patients in critical care settings, particularly when these resources are already stretched. Although health care professionals want to provide a high level of care, it is recognized that patients with OSA can place a strain on health care systems. This article reviews the impact OSA can have on the patient in the perioperative phase and the implications to care providers. Also outlined are the challenges of initiating an OSA screening tool and management protocol. Although updating an institution's policies around perioperative management of the patient with OSA is vital, it can appear to be an overwhelming task to comply with all evidence-based recommendations.

What are microarrays teaching us about sleep?

Many fundamental questions about sleep remain unanswered. The presence of sleep across phyla suggests that it must serve a basic cellular and/or molecular function. Microarray studies, performed in several model systems, have identified classes of genes that are sleep-state regulated. This has led to the following concepts: first, a function of sleep is to maintain synaptic homeostasis; second, sleep is a stage of macromolecule biosynthesis; third, extending wakefulness leads to downregulation of several important metabolic pathways; and, fourth, extending wakefulness leads to endoplasmic reticulum stress. In human studies, microarrays are being applied to the identification of biomarkers for sleepiness and for the common debilitating condition of obstructive sleep apnea.

Bariatric surgery in the treatment of obstructive sleep apnea in morbidly obese patients

BACKGROUND

Weight loss has been shown effective in the treatment of the obstructive sleep apnea-hypopnea syndrome. Regrettably, many obese patients are unable to achieve sustained and useful weight loss by dietary means. Recently, bariatric surgery has emerged as an alternative to treat obesity and many of its comorbidities, although its role for sleep apnea treatment is still not defined.

OBJECTIVES

To evaluate the impact of bariatric surgery on obstructive sleep apnea in morbidly obese patients.

METHODS

In this cohort study, polysomnography, Epworth Sleepiness Scale questionnaire and clinical assessment were performed in 12 of 13 morbidly obese patients with moderate to severe obstructive sleep apnea treated with bariatric surgery through Roux-en-Y gastric bypass procedure after a minimum of 18 months post surgery.

RESULTS

The mean (+/-SD) loss of excess body weight was 70.5 +/- 24%. The mean level obtained in the Epworth Scale was 4.8. There was a significant reduction in the apnea-hypopnea index, from a median of 46.5 (range: 33-140) to 16 (range: 0.9-87) events per hour (p < 0.05), an improvement in mean oxygen saturation from 85.7 +/- 5.1 to 94.5 +/- 3.6% (p < 0.05) and in minimum oxygen saturation from 64.7 +/- 13.4 to 78.7 +/- 13.7% (p < 0.05). The magnitude of the weight loss and the improvements in mean and minimum oxygen saturation were positively correlated, (r = 0.76; p <or= 0.05, and r = 0.59; p <or= 0.05, respectively).

CONCLUSIONS

Weight loss achieved by bariatric surgery is associated with significant long-term improvements in obstructive respiratory event, oxygenation and resolution of daytime somnolence.