Effects of uvulopalatopharyngoplasty on sleep architecture and patterns of obstructed breathing

Referral of adults with obstructive sleep apnea for surgical consultation: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment

INTRODUCTION

This systematic review provides supporting evidence for the accompanying clinical practice guideline on the referral of adults with obstructive sleep apnea (OSA) for surgical consultation.

METHODS

The American Academy of Sleep Medicine commissioned a task force of experts in sleep medicine. A systematic review was conducted to identify studies that compared the use of upper airway sleep apnea surgery or bariatric surgery to no treatment as well as studies that reported on patient-important and physiologic outcomes pre- and postoperatively. Statistical analyses were performed to determine the clinical significance of using surgery to treat obstructive sleep apnea in adults. Finally, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) process was used to assess the evidence for making recommendations.

RESULTS

The literature search resulted in 274 studies that provided data suitable for statistical analyses. The analyses demonstrated that surgery as a rescue therapy results in a clinically significant reduction in excessive sleepiness, snoring, blood pressure (BP), apnea-hypopnea index (AHI), respiratory disturbance index (RDI), and oxygen desaturation index (ODI); an increase in lowest oxygen saturation (LSAT) and sleep quality; and an improvement in quality of life in adults with OSA who are intolerant or unaccepting of positive airway pressure (PAP) therapy. The analyses demonstrated that surgery as an adjunctive therapy results in a clinically significant reduction in optimal PAP pressure and improvement in PAP adherence in adults with OSA who are intolerant or unaccepting of PAP due to side effects associated with high pressure requirements. The analyses also demonstrated that surgery as an initial treatment results in a clinically significant reduction in AHI/RDI, sleepiness, snoring, BP, and ODI and an increase in LSAT in adults with OSA and major anatomical obstruction. Analysis of bariatric surgery data showed a clinically significant reduction in BP, AHI/RDI, sleepiness, snoring, optimal PAP level, BMI, and ODI and an increase in LSAT in adults with OSA and obesity. Analyses of very limited evidence suggested that upper airway surgery does not result in a clinically significant increase in risk of serious persistent adverse events and suggested that bariatric surgery may result in a clinically significant risk of iron malabsorption that may be managed with iron supplements. The task force provided a detailed summary of the evidence along with the quality of evidence, the balance of benefits and harms, patient values and preferences, and resource use considerations.

CITATION

Kent D, Stanley J, Aurora RN, et al. Referral of adults with obstructive sleep apnea for surgical consultation: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment. J Clin Sleep Med. 2021;17(12):2507-2531.

Improving outcomes of hypoglossal nerve stimulation therapy: current practice, future directions and research gaps. Proceedings of the 2019 International Sleep Surgery Society Research Forum

Hypoglossal nerve stimulation (HGNS) has evolved as a novel and effective therapy for patients with moderate-to-severe obstructive sleep apnea (OSA). Despite positive published outcomes of HGNS, there exist uncertainties regarding proper patient selection, surgical technique, and the reporting of outcomes and individual factors that impact therapy effectiveness. According to current guidelines, this therapy is indicated for select patients, and recommendations are based on the Stimulation Therapy for Apnea Reduction (STAR) trial. Ongoing research and physician experiences continuously improve methods to optimize the therapy. An understanding of the way in which airway anatomy, OSA phenotypes, individual health status, psychological conditions and comorbid sleep disorders influence the effectiveness of HGNS is essential to improve outcomes and expand therapy indications. This manuscript presents discussions on current evidence, future directions, and research gaps for HGNS therapy from the 10th International Surgical Sleep Society expert research panel.

Standardized framework to report on the role of sleeping position in sleep apnea patients

PURPOSE

Sleep apnea is a multifactorial illness which can be differentiated in various physiological phenotypes as a result of both anatomical and non-anatomical contributors (e.g., low respiratory arousal threshold, high loop gain). In addition, the frequency and duration of apneas, in the majority of patients with OSA, are influenced by sleeping position. Differences in characteristics between non-positional patients (NPP) and positional patients (PP) suggest another crucial phenotype distinction, a clinical phenotype focusing on the role of sleeping position on sleep apnea. Since this clinical phenotype distinction has therapeutic implications, further research is necessary to better understand the pathophysiology behind this phenotypic trait and to improve management of PP. Therefore, we suggest a standardized framework that emphasizes the role of sleeping position when reporting clinical and research data on sleep apnea.

METHODS

We identified 5 key topics whereby a standardized framework to report on the role of sleeping position would be of added value: (1) sleep study data, (2) anatomical, morphological and physiological factors, (3) drug-induced sleep endoscopy (DISE) findings, (4) sleep apnea management, and (5) effectiveness versus efficacy of positional therapy in sleep apnea management. We performed a literature search to identify evidence to describe and support the rationale behind these 5 main recommendations.

RESULTS

In this paper, we present the rationale behind this construct and present specific recommendations such as reporting sleep study indices (disease severity) and sleep time spent in various sleeping positions. The same is suggested for DISE findings and effect of treatment. Sleep study indices (disease severity), anatomical, morphological, and physiological factors in sleep apnea patients should be reported separately for PP and NPP.

CONCLUSION

Applying these suggestions in future research will improve patient care, assist in better understanding of this dominant phenotype, and will enhance accurate comparisons across studies and future investigations.

Comparison of upper airway collapse patterns and its clinical significance: drug-induced sleep endoscopy in patients without obstructive sleep apnea, positional and non-positional obstructive sleep apnea

PURPOSE

To compare patient characteristics, upper airway (UA) collapse patterns and treatment outcome in obstructive sleep apnea (OSA) patients, including non-positional OSA patients (NPP) and positional OSA patients (PP), and non-OSA.

METHODS

Cohort study of patients screened for OSA in 2012. Polysomnography was performed and UA was evaluated using the VOTE classification during drug-induced sleep endoscopy (DISE). Treatment outcome of MAD and UA surgery was evaluated.

RESULTS

Eight hundred sixty patients were included. Higher BMI, larger neck circumference, and greater age were independent significant predictors for OSA. DISE was performed in 543 patients: 119 non-OSA and 424 OSA patients of whom 257 PP and 167 NPP patients. PP were younger, had smaller neck circumference, lower BMI and apnea-hypopnea index (AHI) than NPP. Collapse at velum (p < 0.001) and oropharynx (p < 0.001) significantly increased the odds for having OSA. Tongue base and epiglottis collapse were, on group level, not determinative for OSA or non-OSA. Complete concentric collapse (CCC) was observed less frequently in PP (31.5%) as compared to NPP (46.1%). After UA surgery, OSA often was cured or improved to less severe positional OSA. Lower efficacy of UA surgery was observed in PP as compared to NPP. No differences were observed in MAD treatment outcome.

CONCLUSIONS

Current study provides insight in patients screened for OSA: collapse at velum and oropharynx significantly determined presence of OSA and CCC occurred less frequently in PP compared to NPP. In addition, residual positional dependency is common after UA surgery. More trials are needed to gain insight in pathophysiology and treatment outcome.

Positional therapy in patients with residual positional obstructive sleep apnea after upper airway surgery

PURPOSE/BACKGROUND

A considerable portion of patients has residual positional obstructive sleep apnea (POSA) after upper airway surgery. Those patients could benefit from additional treatment with positional therapy (PT). The objective of this prospective study was to assess the additional effect of PT in patients with residual POSA after upper airway surgery for sleep apnea.

METHODS

A polysomnography (PSG) was used to diagnose a patient with residual POSA after surgery. After informed consent, patients were treated with PT for 3 months and underwent a follow-up PSG while using the sleep position trainer (SPT). Changes in apnea-hypopnea index (AHI) and sleep position parameters were analyzed. Compliance rates and mean disease alleviation (MDA) were determined.

RESULTS

Thirty-three patients with a median postoperative AHI of 18.3/h sleep were included. With the SPT median AHI dropped to 12.5/h sleep and the Epworth Sleepiness Scale (ESS) improved from 10.0 to 7.0. After 3 months, 37.5 % patients were considered responders of whom 31.3 % had treatment success. The compliance rate with SPT was 89.0 %. MDA was 44.7 % for SPT alone. With the combination of both surgery and SPT, MDA was 65.6 %.

CONCLUSIONS

The results of this study indicate that additional PT in a complex OSA patient population with residual POSA after surgery can increase overall therapeutic effectiveness by improving the median MDA from 39.5 % (effect of surgery alone) to 65.6 % (effect of combining surgery and PT).

Effect of body position and sleep state on obstructive sleep apnea severity in children with Down syndrome

STUDY OBJECTIVES

To investigate the influence of sleep position and sleep state on obstructive sleep apnea (OSA) severity in in children with Down syndrome (DS).

DESIGN

Retrospective review.

SETTING

Sleep disorders laboratory of a tertiary medical center.

PARTICIPANTS

Children with Down syndrome and typically developing children matched for age, gender, apneahypopnea index (AHI), and year of polysomnogram.

MEASUREMENTS AND RESULTS

Sleep variables from baseline polysomnography. Sensor-recorded position (supine, prone, lateral) was expressed as the percentage of total sleep time. The AHI was calculated in each sleep state (NREM, REM), position, and position-sleep state combination. Of 76 DS subjects (55% male) the median age and AHI were 4.6 years (range 0.2-17.8 years) and 7.4 events/h (range 0-133). In all subjects, AHI was higher in REM than NREM (p < 0.05); however, the NREM AHI was higher in DS subjects than controls (p < 0.05). Compared to controls, the percentage of prone sleep was greater in DS subjects (p < 0.05), but the percentage of supine or non-supine (prone plus lateral) sleep was no different. For DS subjects alone, NREM AHI was higher in supine than non-supine sleep (p < 0.05).

CONCLUSION

In DS and non-DS children alike, respiratory events are predominantly REM related. However, when matched for OSA severity, children with DS have a higher NREM AHI, which is worse in the supine position, perhaps indicating a positional effect compounded by underlying hypotonia inherent to DS. These findings illustrate the clinical importance of NREM respiratory events in the DS population and implications for treatment options.

Usefulness of Sleep Endoscopy in Predicting Positional Obstructive Sleep Apnea

Objectives

The aim of the study was to (1) evaluate whether position affects drug-induced sleep endoscopy (DISE) findings in positional and nonpositional patients and (2) determine which areas of the upper airway obstruct in different body positions.

Study Design

Prospective, case-controlled study.

Setting

Academic tertiary care center.

Subjects and Methods

Twenty-two patients with obstructive sleep apnea (OSA) were enrolled. Two groups were individually recruited to make 11 consecutive patients with positional OSA and 11 consecutive patients with nonpositional OSA. Positional OSA was defined by nonsupine 50% reduction in apnea-hypopnea index. DISE was performed with patients in both lateral and supine sleep positions. Upper airway collapse was compared between the sleep positions and between the 2 groups.

Results

Most patients (77%) demonstrated multilevel obstruction on DISE. Nearly all patients with positional OSA (91%) had at least a partial improvement in collapse while in the lateral sleep position. Most of the reduction in collapse involved the tongue base and epiglottis ( P < .05). Sleep position did not significantly alter the upper airway morphology of patients with nonpositional OSA. Apnea-hypopnea index and body mass index were not significantly different between the 2 groups.

Conclusions

Sleep position can change upper airway morphology on DISE, particularly positional OSA patients. Hypopharyngeal collapse was the primary site that improved with change in position. DISE in multiple sleep positions should be considered as part of a minimally invasive approach to surgical therapy of OSA.

Theoretical approach towards increasing effectiveness of palatal surgery in obstructive sleep apnea: role for concomitant positional therapy?

PURPOSE

The aims of this study are to evaluate the effect of palatal surgery (uvulopalatopharyngoplasty (UPPP) or Z-palatoplasty (ZPP)) with or without (+/-) concomitant radiofrequent ablation of the base of the tongue (RFTB) on body position-specific apnea-hypopnea index (AHI) values in patients with obstructive sleep apnea (OSA) and to compare this treatment outcome to the theoretical effect of (addition of) positional therapy (PT).

METHODS

Retrospective analysis of pre- and posttreatment polysomnographies in 139 patients who had undergone UPPP/ZPP +/- RFTB was performed. Hypothetical evaluation of the effects of (addition of) ideal PT on AHI in positional OSA (POSA) patients was carried out.

RESULTS

Median AHI significantly decreased from 18.0 to 11.2 (p < 0.001). Median AHI in all separate positions decreased significantly as well. Sixty-eight patients suffered from POSA and showed a significant decrease in median AHI from 15.5 to 11.5 (p = 0.002). In the 71 non-positional OSA (NPOSA) patients, the significant AHI decrease was more outspoken, from 23.0 to 11.0 (p < 0.001). Our hypothetical model to treat POSA patients with an ideal PT (as monotherapy or in addition to surgery) resulted in a significant median AHI decrease from 18.0 to 4.5 (p < 0.0001).

CONCLUSIONS

UPPP/ZPP +/- RFTB significantly reduces AHI and all body position-specific AHI values. This reduction is significantly higher in NPOSA than in POSA patients. When considering UPPP/ZPP +/- RFTB, the effect of body position needs to be taken into account. PT, either as monotherapy or in addition to surgery, theoretically has shown to improve treatment results dramatically in POSA patients. Prospective, controlled trials focusing on the effects of this combination of treatments should further evaluate this hypothetical conclusion.

Positional Dependency and Surgical Success of Relocation Pharyngoplasty among Patients with Severe Obstructive Sleep Apnea

Objective

To examine the effect of positional dependency on surgical success among patients with severe obstructive sleep apnea (OSA) following modified uvulopalatopharyngoplasty, known as relocation pharyngoplasty.

Study Design

Case series with planned data collection.

Setting

Tertiary referred center.

Subjects and Methods

Standard nocturnal polysomnography was used to compare the apnea-hypopnea index (AHI) in different sleep positions before and after relocation pharyngoplasty in 47 consecutive patients with severe OSA (AHI, 59.5 ± 18.2 events/hour; Epworth Sleepiness Scale [ESS] scores, 12.2 ± 4.4) who failed continuous positive airway pressure therapy. Positional (dependency) OSA was defined when the supine:non-supine AHI ratio was >2, otherwise it was defined as nonpositional OSA. Surgical success was defined as a ≥50% reduction in AHI and a postoperative AHI of ≤20 events/hour. Polysomnographic parameters, ESS, and surgical success following surgery were recorded.

Results

Of the 47 patients, 27 (57%) had positional OSA and 20 (43%) nonpositional OSA. The nonpositional OSA patients had higher AHI and ESS scores than the positional OSA patients ( P = .002 and .104, respectively). Relocation pharyngoplasty significantly improved AHI and ESS scores in both positional and nonpositional OSA groups 6 months postoperatively ( P < .05). The overall surgical success rate was 49%; however, positional OSA patients had a significantly higher success rate than nonpositional OSA patients (67% vs 25%, P = .008).

Conclusion

The presence of positional dependency at baseline was a favorable outcome predictor of surgical success among severe OSA patients undergoing relocation pharyngoplasty.

The undervalued potential of positional therapy in position-dependent snoring and obstructive sleep apnea-a review of the literature

Purpose

Research during the past 10–20 years shows that positional therapy (PT) has a significant influence on the apnea–hypopnea index. These studies are predominantly performed as case series on a comparably small number of patients. Still, results have not found their way into the daily diagnostic and treatment routine. An average of 56 % of patients with obstructive sleep apnea (OSA) have position-dependent OSA (POSA), commonly defined as a difference of 50 % or more in apnea index between supine and non-supine positions. A great deal could be gained in treating patients with POSA with PT. The aim of this paper was to perform a thorough review of the literature on positional sleep apnea and its therapy.

Methods

A broad search strategy was run electronically in the MEDLINE and EMBASE databases using synonyms for position and sleep apnea.

Results

Sixteen studies were found which examined the effect of PT on OSA. In this literature review, we discuss the various techniques, results, and compliance rates.

Conclusion

Long-term compliance for PT remains an issue, and although remarkable results have been shown using innovative treatment concepts for PT, there is room for both technical improvement of the devices and for further research.

Exploration of the relationship between sleep position and isolated tongue base or multilevel surgery in obstructive sleep apnea

This study aimed to elucidate the role of sleep position as a confounding factor on apnea hypopnea index (AHI) and surgical success in isolated tongue base or multilevel surgery. This study was conducted using retrospective analysis of patients who underwent hyoid suspension because of obstructive sleep apnea (OSA), in the St. Lucas Andreas Hospital, Amsterdam, The Netherlands, from 2004 to 2011. Concurrent surgical treatment was documented. Sleep positions and corresponding AHIs before and after surgery were compared. A total of 130 patients were included. 94 patients underwent surgery of base of tongue and palate (either uvulopalatopharyngoplasty or Z-palatoplasty), of whom 72 underwent concurrent radiofrequent thermotherapy of the base of tongue. 36 patients underwent base of tongue surgery alone, of whom 22 underwent concurrent radiofrequent thermotherapy of the base of tongue. 65 patients either had a successful reduction in AHI or in AI. Isolated tongue base or multilevel surgery was as successful on the supine AHI as it was on the AHI in other sleeping positions. Surgery was not more successful in the group with position-dependent patients as compared with the non-position-dependent patients (P = 0.615). Successful and non-successful surgical results could not be explained by variations in percentages of supine sleep position. Sleep position is not a confounding factor on surgical outcomes in tongue base surgery. The results of isolated base of tongue or multilevel surgery in position-dependent OSA patients leave room for improvement, possibly through positional therapy.

Primary and secondary telegnathic maxillomandibular advancement, with or without adjunctive procedures, for obstructive sleep apnea in adults: a literature review and treatment recommendations

PURPOSE

To further define the role, surgical principles, and therapeutic efficacy of primary and secondary maxillomandibular advancement (MMA), with and without intrapharyngeal or extrapharyngeal adjunctive procedures, for obstructive sleep apnea in adults.

MATERIALS AND METHODS

A review of the literature, using mean percent reduction in apnea hypopnea index as the primary outcome measure of therapeutic efficacy for standardized comparison. Other occasionally reported MMA outcome parameters were sleep staging variables, lowest oxyhemoglobin saturation levels, Epworth scores, blood pressure changes, lateral cephalometric data, and complications.

RESULTS

Mean percent reduction in apnea hypopnea index was 92.1% for primary MMA with extrapharyngeal procedures, 88.4% for primary MMA, 86.6% for secondary MMA, 79.4% for primary MMA with intrapharyngeal procedures, 53.0% for non-MMA multilevel surgery, 31.3% for uvulopalatopharyngoplasty, and 89.8% for nasal continuous positive airway pressure. Treatment recommendations for telegnathic MMA included surgical goals and guidelines, indications and staging protocols, surgical principles and techniques, and postoperative airway management.

CONCLUSIONS

Primary and secondary MMA are highly therapeutic, and extrapharyngeal are more therapeutic than intrapharyngeal procedures when performed concomitantly with primary MMA. However, long-term success of obstructive sleep apnea treatment should be measured by a yet undefined comprehensive algorithm of standardized multiple weighted outcome parameters.

Effect of successful surgical treatment on changes of position during sleep in adults with obstructive sleep apnea syndrome

OBJECTIVES

The purpose of this study was to evaluate the changes of position during sleep as determined by polysomnography before and after upper airway surgery for obstructive sleep apnea syndrome in patients with no response to surgery ("nonresponse group") and in those who did have a response to surgery ("response group").

METHODS

We analyzed a total of 106 polysomnograms from 53 subjects and compared the preoperative-postoperative differences in the frequency of positional changes during sleep and the distribution of sleep positions between the nonresponse group (n = 25) and the response group (n = 28). Surgical response was defined as a greater than 50% decrease in the postoperative apnea-hypopnea index.

RESULTS

The positional change index in the response group was significantly reduced (from 4.2 +/- 3.8 to 2.6 +/- 1.6; p = 0.038), whereas the positional change index in the nonresponse group did not significantly change (from 3.4 +/- 2.0 to 3.4 +/- 2.1; p = 0.861). The proportion of sleep time spent in the supine position did not significantly change in the nonresponse group (from 62.4% +/- 18.1% to 60.5% +/- 21.3%; p = 0.904) or the response group (from 55.5% +/- 23.9% to 60.1% +/- 23.1%; p = 0.412).

CONCLUSIONS

The frequency of positional changes during sleep was significantly decreased with the improvement of respiratory disturbances and arousals in the response group after upper airway surgery.

Surgical modifications of the upper airway for obstructive sleep apnea in adults: a systematic review and meta-analysis

A substantial portion of patients with obstructive sleep apnea (OSA) seek alternatives to positive airway pressure (PAP), the usual first-line treatment for the disorder. One option is upper airway surgery. As an adjunct to the American Academy of Sleep Medicine (AASM) Standards of Practice paper, we conducted a systematic review and meta-analysis of literature reporting outcomes following various upper airway surgeries for the treatment of OSA in adults, including maxillomandibular advancement (MMA), pharyngeal surgeries such as uvulopharyngopalatoplasty (UPPP), laser assisted uvulopalatoplasty (LAUP), and radiofrequency ablation (RFA), as well as multi-level and multi-phased procedures. We found that the published literature is comprised primarily of case series, with few controlled trials and varying approaches to pre-operative evaluation and post-operative follow-up. We include surgical morbidity and adverse events where reported but these were not systematically analyzed. Utilizing the ratio of means method, we used the change in the apnea-hypopnea index (AHI) as the primary measure of efficacy. Substantial and consistent reductions in the AHI were observed following MMA; adverse events were uncommonly reported. Outcomes following pharyngeal surgeries were less consistent; adverse events were reported more commonly. Papers describing positive outcomes associated with newer pharyngeal techniques and multi-level procedures performed in small samples of patients appear promising. Further research is needed to better clarify patient selection, as well as efficacy and safety of upper airway surgery in those with OSA.

The characteristics of five patients with obstructive sleep apnea whose apnea-hypopnea index deteriorated after uvulopalatopharyngoplasty

The objective of this retrospective, consecutive, case series design study was to determine the number of unselected patients with obstructive sleep apnea (OSA) who deteriorated after uvulopalatopharyngoplasty (UPPP). Sixteen of 27 patients at the Sleep Clinic at Veterans Affairs Medical Center who underwent UPPP for OSA and who completed both a pre- and postpolysomnogram were studied. After comparing the apnea-hypopnea index (AHI) before and after UPPP, three groups of patients were identified: deteriorators, unchanged, and improvers. In five patients (31%), the AHI increased by more than 10% after UPPP (deteriorators); in four (25%), the AHI showed a change in either direction of less than 10% (unchanged); and in the remaining seven (44%), the AHI decreased by more than 10% after UPPP (improvers). The AHI deteriorated in five of 16 (31%) unselected patients with OSA in our clinic population who underwent UPPP. The mean pre-UPPP AHI was lower in the patients who deteriorated relative to all other patients (P = 0.02). We suggest that patients who undergo UPPP should have a post-UPPP polysomnogram to determine whether they have improved or deteriorated after the procedure and that alternative forms of treatment may be needed in some patients.

Single-stage CO2 laser assisted uvuloplasty for treatment of snoring and mild obstructive sleep apnoea

PURPOSE

The purpose of this study was to describe a single-stage laser assisted uvuloplasty (uvulectomy) and to determine its effectiveness in treatment of snoring and mild obstructive sleep apnoea (OSA).

PATIENTS AND METHODS

All patients treated with laser assisted uvuloplasty in a 49-month period for snoring and/or mild OSA were studied. Frequency of snoring before and after surgery, loudness of snoring and postoperative discomfort were investigated. Patients were asked to evaluate change in daytime energy, sleep habits, missed days of work and also overall satisfaction following laser assisted uvuloplasty.

RESULTS

Thirty patients underwent a single-stage laser assisted uvuloplasty. A preoperative diagnosis of OSA was established in 19 patients, the remaining 11 patients were treated for snoring. There were no complications and only one patient required an additional stage. A questionnaire was completed by 18 patients (10 patients diagnosed with sleep apnoea, and eight patients with snoring only). Preoperatively the frequency of snoring averaged 9.3 cm on a visual analogue scale. Postoperatively there were 12 patients with either none or very minimal snoring and six patients who had an average score of 3.2. Loudness of snoring also decreased from an average of 5.4 to 2.5 cm. Postoperative discomfort averaged 1.1 cm. Improvement in sleep was noted by 16 patients and improved daytime energy was noted by 17 patients. Eleven patients reported that they missed at least one day of work postoperatively with an average of 3 days missed. Patient satisfaction was reported by 17 patients with only one stating that he was unsatisfied with the procedure.

CONCLUSIONS

Laser-assisted uvuloplasty (uvulectomy) is an effective surgical procedure for treatment of snoring and some types of OSA. A single-stage procedure appears to be effective and may further decrease the morbidity associated with this disease.

The effect of body posture on sleep-related breathing disorders: facts and therapeutic implications

The aggravating effect of the supine body position on breathing abnormalities during sleep was recognized from the earliest studies on sleep breathing disorders. Most of the anatomical and physiological correlates of this phenomenon appear to be due to the effect of gravity on the upper airway. Although few articles have been published on this topic, it has been shown in a large population of obstructive sleep apnoea (OSA) patients that more than half of them are Positional Patients, i.e. they have at least twice as many apnoeas/hypopnoeas during sleep in the supine posture as in the lateral position. This positional phenomenon is influenced by factors such as Respiratory Disturbances Index (RDI), Body Mass Index (BMI), age and sleep stages. The sleep supine posture not only increases the frequency of the abnormal breathing events but also their severity. This sleep posture also has a detrimental effect on snoring, as well as on the optimal CPAP pressure. Positional Therapy, i.e. the avoidance of the supine posture during sleep, is a simple behavioural therapy for many mild to moderate OSA patients. Unfortunately, only a few studies, including only a few patients, have investigated this form of therapy. Although the results of these studies are promising, the lack of a reliable long-term evaluation of its efficacy is perhaps an important reason why this form of therapy has not been widely accepted. Since mild to moderate OSA patients are the majority of the OSA patients and since without treatment, a large percentage of them will develop a more severe form of the disease, a thorough evaluation with a major emphasis on the long-term effectiveness of this form of therapy is urgently needed.

Effectiveness of prosthetic mandibular advancement for obstructive sleep apnea: analysis by sleep position

Fifteen patients with obstructive sleep apnea were treated using prosthetic mandibular advancement (PMA). Each patient was evaluated in the supine and lateral decubitus positions with and without PMA. After PMA treatment, the mean intraesophageal pressure (Peso) in the supine position improved from -42.6 to -27.3 cmH2O and the mean apnea + hypopnea index (AHI) decreased from 48.8/h to 23.7/h. The mean Peso in the lateral decubitus position improved from -27.9 to -18.6 cmH2O and the mean AHI decreased from 9.6/h to 6.6/h. With PMA, respiratory, disturbance during sleep further improved by changing the body position from the supine to lateral decubitus position.

Respiration in NREM and REM sleep after upper airway surgery for obstructive sleep apnoea

To verify whether upper airway surgery in obstructive sleep apnoea syndrome affects differently respiration in NREM and REM sleep, 22 patients were studied by polysomnography before and three months after surgical treatment. On the average, treatment improved respiration during both sleep states, but no significant interaction was found between sleep state and effect of surgical treatment. According to the response to treatment, three groups of patients were identified: the first group (N = 6), with an improvement in apnoea-hypopnoea index (AHI), percentage of sleep time spent in apnoea and hypopnoea (time in AH) and mean oxyhaemoglobin saturation (SaO2) in both NREM and REM sleep; the second group (N = 5), with an improvement in AHI only in NREM sleep, associated with improvement in mean SaO2 in both sleep states; the third group (N = 11), without any improvement in AHI and time in AH, either associated (N = 5) or not (N = 6) with an improvement in mean SaO2 in both sleep states. An increase in the percentage of hypopnoeas out of the total AHI after treatment could partly account for the apparent discrepancy between AHI and mean SaO2 behaviour in the subjects of the second group, but not in the patients of the third group who improved their mean SaO2. Mixed apnoeas occurred before surgery in six subjects; they remained numerous after surgery only in two subjects who did not show any SaO2 improvement. In conclusion, the degree of improvement in respiration after upper airway surgery was similar in every patient in NREM and REM sleep.

Laser-assisted uvulopalatoplasty for snoring and obstructive sleep apnea: results in 170 patients

Laser-assisted uvulopalatoplasty (LAUP) is a procedure for the treatment of snoring and, possibly, sleep apnea. Between July 1993 and December 1994, the authors prospectively evaluated 541 consecutive patients referred to their teaching hospital for possible LAUP to treat loud, disruptive snoring. Of these patients, 274 (51%) had one or more LAUP treatments. As of January 1995, LAUP treatment courses were completed in 170 patients. In this paper, the authors report preliminary results on the use of LAUP in these patients. Among the 170 patients, 105 (62%) had a diagnosis of snoring and 65 (38%) obstructive sleep apnea syndrome (OSAS) based on preoperative polysomnography. LAUP treatment in the snoring only patients resulted in complete or nearly complete elimination of snoring in 63 patients (60%), partial improvement of snoring in 30 patients (29%), and no improvement in 11 patients (10%). Of the 65 OSAS patients treated with LAUP, postoperative polysomnograms were obtained in 33 patients (51%). Surgical success was achieved in 16 (48%) of the 33 patients. However, 7 patients (21%) had repeat polysomnograms that were worse than their preoperative polysomnograms, and 5 patients (15%) had no significant change. The results of this study suggest that LAUP may be a viable surgical option for patients with snoring and mild sleep apnea.