Management of obstructive sleep apnoea/hypopnoea syndrome

Burden of obstructive sleep apnea and CPAP use on patients with chronic rhinosinusitis

OBJECTIVE

To evaluate the impact of obstructive sleep apnea (OSA) on the quality-of-life (QoL) of patients with chronic rhinosinusitis (CRS).

METHODS

Retrospective cohort study of all adult patients with CRS presenting to our rhinology clinic between August 2020 and February 2023 was performed. OSA was established based on positive polysomnography. Patients' characteristics, apnea-hypopnea index, comorbidities, endoscopy scores, and SNOT-22 scores were collected.

RESULTS

A total of 513 patients with CRS were included, 127 patients with OSA and 386 without OSA. CRS patients with OSA were older (p < 0.001), had higher BMI (p < 0.001), more likely to be males (p = 0.07), more likely to have asthma (p < 0.001), and more likely to have COPD (p = 0.001). Presence of nasal polyps did not differ between the two groups. Baseline SNOT-22 scores were worse in the OSA cohort (44.4 vs 40.5, p = 0.064) secondary to worse sleep (13.4 vs 11.1; p = 0.002) and psychological (14.2 vs 11.5; p = 0.002) domains. Worse SNOT scores were strongly associated with presence of OSA after adjusting for confounding variables, including age, gender, asthma, allergic rhinitis, nasal septal deviation, and smoking status.

CONCLUSION

OSA is an independent negative contributor to the disease specific QoL in patients with CRS. CPAP use does not seem to affect the QoL in CRS patients with OSA. Further research is warranted to explore the impact of OSA in the outcome of medical and surgical treatment of CRS patients.

Mood, sleepiness, and weight gain after three years on CPAP therapy for sleep apnoea

Background: The prevalence of obstructive sleep apnoea syndrome (OSAS) keeps on rising. Daytime sleepiness resulting from fragmented sleep is the prime symptom, and obesity the major risk factor for OSAS. Quality of life with OSAS is often affected by depressive symptoms and anxiety. Nasal continuous positive airway pressure (CPAP) therapy reduces daytime sleepiness, but the results on the effect on mood, physical activity, and weight are controversial especially on long-term therapy. Purpose of this study was to evaluate these factors and predictors of weight gain during long-term CPAP therapy.

Methods: Consecutive patients (n = 223), referred to sleep study with suspected OSAS, were enrolled. Patients underwent a cardiorespiratory polygraphy at baseline and a battery of questionnaires was completed, both at baseline, and after three years of follow-up. Total of 149 (67%; M 65, F 84) patients completed the follow-up. Of the 149 patients, 76 (51.0%; M 32, F 44) used CPAP.

Results: In this study, depressive symptoms, anxiety, and sleepiness were alleviated during CPAP therapy. However, therapy did not have an influence on cravings of different food categories, or exercise habits and exercise duration. From the various factors studied, solely higher adherence to CPAP therapy was associated with weight gain.

Conclusions: This research provides further evidence that long-term CPAP therapy in patients with OSAS not only decreases sleepiness and improves sleep quality but could also alleviate depressive symptoms and anxiety. In addition, our study reinforces that CPAP therapy alone is not sufficient for weight management in patients with OSAS. Regardless of comprehensive battery of questionnaires, we were unable to establish markers predicting weight gain during therapy. We advise on life-style counselling and weight management program to all patients with obesity on CPAP therapy.

Association of Allergic Rhinitis With Change in Nasal Congestion in New Continuous Positive Airway Pressure Users

Importance

Nasal congestion occurring after continuous positive airway pressure (CPAP) treatment initiation impairs CPAP adherence. Allergic rhinitis is associated with worsening nasal congestion in patients who are exposed to nonallergic triggers. Use of CPAP presents potential nonallergic triggers (eg, humidity, temperature, pressure, and airflow).

Objective

To compare nasal congestion among CPAP users with allergic rhinitis, nonallergic rhinitis, and no rhinitis. We hypothesize that CPAP patients with baseline allergic rhinitis are more likely to experience a worsening of nasal congestion (or less improvement in nasal congestion) compared with patients with no baseline rhinitis.

Design, Setting, and Participants

This prospective cohort study included consecutive patients newly diagnosed with obstructive sleep apnea in a tertiary sleep center who were using CPAP therapy 3 months after diagnosis. Baseline rhinitis status was assigned as allergic rhinitis, nonallergic rhinitis, or no rhinitis, based on questionnaire responses and past allergy testing. Data were collected from 2004 to 2008 and analyzed from July 2019 to February 2020.

Main Outcomes and Measures

At baseline before CPAP exposure and again 3 months later, subjective nasal congestion was measured with the Nasal Obstruction Symptom Evaluation (NOSE) scale and a visual analog scale (VAS), each scored from 0 to 100 (100 = worst congestion). Changes in nasal congestion were tested over 3 months for the whole cohort, within each rhinitis subgroup (paired t test), and between rhinitis subgroups (multivariate linear regression).

Results

The study cohort comprised 102 participants, of whom 61 (60%) were male and the mean (SD) age was 50 (13). The study included 23 (22.5%) participants with allergic rhinitis, 67 (65.7%) with nonallergic rhinitis, and 12 (11.8%) with no rhinitis. Nasal congestion improved from baseline to 3 months in the whole cohort (mean [SD] NOSE score, 38 [26] to 27 [23], mean [SD] change, -10 [23]; 95% CI, -15 to -6; mean [SD] VAS score, 41 [27] to 32 [28]; mean [SD] change, -10 [26]; 95% CI, [-15 to -4]) and in each rhinitis subgroup. Adjusted improvement in nasal congestion at 3 months was significantly less in the allergic rhinitis subgroup compared with the no rhinitis subgroup (positive difference means less improvement) compared with baseline: NOSE score 14 (95% CI, 1 to 28) and VAS score 15 (95% CI, 0 to 30).

Conclusions and Relevance

Initiation of CPAP was associated with improved subjective nasal congestion, but less improvement in patients with baseline allergic rhinitis. Baseline allergic rhinitis may predict which patients are more vulnerable to potential congestive effects of CPAP.

Effect of continuous positive airway pressure on insulin growth factor-1 in patients with obstructive sleep apnea: a meta-analysis

OBJECTIVE

Obstructive sleep apnea (OSA) has been recognized as being associated with low level of insulin growth factor-1 (IGF-1). However, the impact of OSA treatment using continuous positive airway pressure (CPAP) on IGF-1 remains controversial. We performed a meta-analysis to determine whether effective CPAP therapy could increase IGF-1 levels.

DESIGN

Two reviewers independently searched PubMed, Cochrane library, Embase and Web of Science before September 2014. Information on characteristics of subjects, study design and pre- and post-CPAP treatment of serum IGF-1 was extracted for analysis. Standardized mean difference (SMD) was used to analyze the summary estimates for CPAP therapy.

RESULTS

Six articles with 168 patients were included in this meta-analysis, including five observational studies and one randomized controlled study. The meta-analysis showed that CPAP was associated with a statistically significant increase in IGF-1 in OSA patients (SMD=-0.436, 95% confidence interval=-0.653 to -0.218, P=0.000).

CONCLUSIONS

This meta-analysis suggested that CPAP therapy was associated with an increase in IGF-1 in patients with OSA. Further large-scale, well-designed interventional investigations are needed to clarify this issue.

Effect of prone positioning in mild to moderate obstructive sleep apnea syndrome

BACKGROUND

Sleeping in prone position could be effective in the management of obstructive sleep apnea (OSA) syndrome by reducing the gravity effect on the upper airway and hence collapsibility. Effect of pure prone positioning (PPP) treatment was investigated in mild to moderate OSA.

PATIENTS AND METHODS

Twenty-nine mild to moderate OSA patients (17 males, 12 females) who gave informed consent were tested with polysomnography at diagnostic and PPP nights. PPP device consisted of a pillow mounted on a table with a hole in the middle keeping the neck 180° extended in prone position. Mean ± SD of age and AHI were 48.4 ± 10.6 and 15.5 ± 6.2, respectively. Patients did not have abdominal and/or truncalobesity, or any condition that could interfere with prone sleeping.

RESULTS

AHI (mean difference: PPP treatment - diagnostic night: -5.2/h, 95% confidence interval [CI]: -0.1/h to -10.3/h, p = 0.04) and sleep oxygen saturation below 90% (mean difference: -1.80%, 95% CI: -0.22% to -3.37%, p = 0.02) and sleep efficiency (81.0 ± 21.2% and 88.1 ± 7.1 %, respectively, p = 0.02) were significantly lower in PPP than diagnostic night. Response to PPP treatment defined as AHI <5/h in the PPP night was observed in 15 (51.7%) patients, with a better rate in female than male patients (9/12 vs. 6/17, respectively, p = 0.03).

CONCLUSIONS

To our knowledge, this is the first study to examine the effect of prone positioning in the treatment of mild to moderate OSA. Application of PPP with a more comfortable design in a randomized clinical trial is required to investigate its long term effect in the treatment of mild to moderate OSA.

Bimaxillary advancement as the initial treatment of obstructive sleep apnea: five years follow-up of the pori experience

Objectives

Bimaxillary advancement surgery has proven to be effective treatment of obstructive sleep apnea syndrome. According to the Stanford protocol upper airway soft tissue surgery or advancement of tongue by chin plastic surgery is first carried out and if obstructive sleep apnea persists, then bimaxillary advancement is done. This study describes the 5 year outcome of 13 obstructive sleep apnea patients in whom the Stanford protocol was omitted and bimaxillary advancement was carried out as initial surgical treatment.

Material and Methods

Patients were divided in two groups. Group A comprised patients with obstructive sleep apnea (OSAS) confirmed by polysomnography in whom ODI-4 (oxygen desaturation index) was 5 or more. Group B consisted of patients with occlusal problems needing orthognathic surgery and with OSAS symptoms but no clear disease on polysomnography, where the ODI-4 index was less than 5. Both groups were treated with bimaxillary advancement surgery (BAS) as initial therapy.

Results

In the group A mean ODI-4 was 17.8 (SD 12) before treatment and 3.5 (SD 3.4) at 5-year follow-up (P = 0.018 in paired differences t-test). In group B the ODI-4 remained below 5. In group A mean saturation improved from 94.3% (SD 1.6) to 96.3% (SD 2), P = 0.115 and in group B from 96.3% (SD 1.2) to 97.8% (SD 1.7), P = 0.056 (in paired differences t-test). The static charge sensitive bed evaluation showed improvement in all patients except one.

Conclusions

Bimaxillary advancement surgery is safe and reliable as an initial surgical treatment of obstructive sleep apnea syndrome.

A new animal model of obstructive sleep apnea responding to continuous positive airway pressure

STUDY OBJECTIVES

An improved animal model of obstructive sleep apnea (OSA) is needed for the development of effective pharmacotherapies. In humans, flexion of the neck and a supine position, two main pathogenic factors during human sleep, are associated with substantially greater OSA severity. We postulated that these two factors might generate OSA in animals.

DESIGN

We developed a restraining device for conditioning to investigate the effect of the combination of 2 body positions-prone (P) or supine (S)-and 2 head positions-with the neck flexed at right angles to the body (90°) or in extension in line with the body (180°)-during sleep in 6 cats. Polysomnography was performed twice on each cat in each of the 4 sleeping positions-P180, S180, P90, or S90. The effect of continuous positive airway pressure (CPAP) treatment was then investigated in 2 cats under the most pathogenic condition.

SETTING

NA.

PATIENTS OR PARTICIPANTS

NA.

INTERVENTIONS

NA.

MEASUREMENTS AND RESULTS

Positions P180 and, S90 resulted, respectively, in the lowest and highest apnea-hypopnea index (AHI) (3 ± 1 vs 25 ± 2, P < 0.001), while P90 (18 ± 3, P<0.001) and S180 (13 ± 5, P<0.01) gave intermediate values. In position S90, an increase in slow wave sleep stage 1 (28% ± 3% vs 22% ± 3%, P<0.05) and a decrease in REM sleep (10% ± 2% vs 18% ± 2%, P<0.001) were also observed. CPAP resulted in a reduction in the AHI (8 ± 1 vs 27 ± 3, P<0.01), with the added benefit of sleep consolidation.

CONCLUSION

By mimicking human pathogenic sleep conditions, we have developed a new reversible animal model of OSA.

Sleep apnea in patients with oral cavity and oropharyngeal cancer after surgery and chemoradiation therapy

OBJECTIVE: To determine the point prevalence of sleep apnea in patients following oral and oropharyngeal cancer treatment at a major tertiary care referral center.

STUDY DESIGN: A retrospective cross-sectional survey.

SUBJECTS AND METHODS: Twenty-four patients with established oral or oropharyngeal cancer were submitted to overnight polysomnography. The surgical group consisted of 15 patients (11 male, 4 female; average age 64.2 yrs) having undergone primary surgery with radial forearm free flap reconstruction. The remaining patients (5 male, 4 female; average age 54.8 yrs) were treated nonsurgically with chemoradiation therapy. The fatigue-related daytime sleepiness was measured with the Epworth sleepiness scale (ESS).

RESULTS: Eleven patients in the surgical group and three in the nonsurgical group had a respiratory disturbance index (RDI) greater than 15 (odds ratio = 5.5, P = 0.092). Twelve patients in the surgical group and five in the nonsurgical group had significant oxygen desaturation during sleep hours (odds ratio = 3.3, P = 0.356). There was no observed significant correlation between RDI and oxygen desaturation (r2 = 0.28), nor was there any observed association between the RDI and ESS score (r2 = 0.18).

CONCLUSION: This preliminary study has suggested that surgical patients in our cohort have a higher prevalence of moderate to severe obstructive sleep apnea in the postoperative period, when tested, compared with a nonsurgical group. A small sample size and incomplete matching on important cofactors of interest, such as primary site location, body mass index, and thyroid function, limit this study. A pretreatment and post-treatment analysis is obviously required to demonstrate any significant level of association between treatment type and sleep apnea status.

© 2010 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved.

LUPP relieves partial upper airway obstruction during sleep in patients with velopharyngeal narrowing

CONCLUSION

Patients with upper airway narrowing at the soft palate level and partial upper airway obstruction during sleep seem to benefit from laser-assisted uvulopalatoplasty (LUPP) in terms of decreased velopharyngeal collapsibility and improved nocturnal breathing.

OBJECTIVES

The current operative treatments for obstructive sleep apnea syndrome (OSAS) are not very effective compared with continuous positive airway pressure (CPAP). It has been suggested that active treatment should be performed earlier, when sleep apnea is present in a milder form. The main problem is identifying progressive sleep apnea. The present study assessed the efficacy of LUPP in patients with partial upper airway obstruction during sleep diagnosed by means of a static charge-sensitive bed (SCSB) combined with oxyhemoglobin desaturation recording and digital fluoroscopy-based collapsibility estimation.

METHODS

LUPP was carried out in 27 patients under local anesthesia as day surgery. Digital fluoroscopy and SCSB were recorded preoperatively and 6 months after LUPP.

RESULTS

Partial upper airway obstruction events and arterial oxyhemoglobin desaturations during sleep decreased significantly. Digital fluoroscopy revealed that the minimal anteroposterior dimension increased and collapsibility decreased at the level where velopharyngeal obstruction occurred, the soft palate.

Growth hormone/insulin-like growth factor-I axis in obstructive sleep apnea syndrome: an update

Obstructive sleep apnea syndrome (OSAS) is a serious, prevalent condition that has significant mortality and morbidity when untreated. It is strongly associated with obesity and is characterized by changes in the serum levels or secretory patterns of several hormones. In particular, obese patients with OSAS show a peculiar reduction of both spontaneous and stimulated GH secretion coupled with reduced IGF-I concentrations and impaired peripheral sensitivity to GH. These endocrine abnormalities are more marked than those observed in non-apneic obese subjects, and are likely to be due to the effects of hypoxia and sleep fragmentation on hormone secretory pattern. The GH/IGF-I axis activity disruption can be responsible, at least in part, for metabolic alterations, which are common in OSAS and increase the risk of cardiovascular events as well as mortality. Effective assessment and management of OSAS may correct endocrine changes, improve quality of life, and prevent associated morbidity or death.

Uvulopalatopharyngoplasty with an ultrasound scalpel or laser: is there a difference?

Uvulopalatopharyngoplasty (UPPP) is used for treatment of the obstructive sleep apnoea syndrome, mainly in the lower range of the apnoea-hypopnea index or partial upper airway obstruction. Significant severe pain after UPPP is associated in the area having surgery and therefore less pain causing methods should be investigated. In this study, we compared laser-assisted and ultrasound scalpel-performed UPPP. Sleep apnoea patients (n = 40) recruited to the study were divided into two groups. UPPP was performed with either laser-assisted or an ultrasound scalpel. Perioperative bleeding, operating room time and duration of operation together with histological injury of soft palate were analysed. A postoperative follow-up questionnaire included a self analysis of pain, dietary intake and pain drug consumption. In the same follow-up form, filled in by patients themselves, possible side effects and adequacy of pain medication together with any postoperative haemorrhage events were recorded during 10-day study period after UPPP. The ultrasound scalpel group had significantly fewer haemorrhagic events (P = 0.037) during postoperative follow-up time after UPPP when compared to laser-assisted group. The pain values of all 40 patients were significantly higher in the morning than in the afternoon (P < 0.001) or evening (P < 0.001). Pain increased up to the fifth postoperative day (visual analogue scale, VAS = 46). The significant relief of pain to the mild level (VAS < 30 mm) occurred at ninth and tenth postoperative day. The ultrasound scalpel used as a surgical method in UPPP did not offer significant comprehensive benefits in this study compared to laser-assisted UPPP. Exclusively, postoperative haemorrhage events were minor, paralleling findings of previous studies where ultrasound scalpel had been used for tonsillectomy. We conclude that the ultrasound scalpel is comparable to laser-assisted UPPP.

Effect of Nasal Continuous Positive Airway Pressure Therapy on Health-related Quality of Life in Sleep Apnoea Patients Treated in the Routine Clinical Setting of a University Hospital

The effectiveness and cost-utility of nasal continuous positive airway pressure (nCPAP) treatment was evaluated in obstructive sleep apnoea syndrome (OSAS), using a 15D health-related quality of life (HRQoL) instrument in a routine clinical setting. In total, 78 OSAS patients (43 receiving nCPAP; 35 receiving lifestyle guidance) were included in the study. nCPAP treatment had a minor effect on the total HRQoL score; only the dimension of sleep improved in both groups. The mean ± SD number of quality-adjusted life years (QALYs) gained was 0.016 ± 2.34 in the nCPAP group and 0.386 ± 1.16 in the lifestyle guidance group. The mean cost per QALY gained was €73 375 for the nCPAP group and €845 for the lifestyle guidance group. The effect of nCPAP treatment on the HRQoL in a population of unselected OSAS patients was surprisingly small and the cost per QALY gained was high.

Low level of IGF-1 in obesity may be related to obstructive sleep apnea syndrome

The aim of this study was to compare serum insulin-like growth factor (IGF-1) levels in patients with obstructive sleep apnea syndrome (OSAS) with those of nonapneic controls and to determine the risk factors of low IGF-1 levels in patients with OSAS. The study included 39 newly diagnosed moderate-to-severe OSAS patients and 36 nonapneic controls. Overnight polysomnography (PSG) was performed in all patients. The circulating levels of IGF-1 in the OSAS group were significantly lower than those of the control group (p < 0.05). There was a significant negative correlation between IGF-1 and logarithmic transformation (Ln) of the apnea-hypopnea index (AHI), duration of apnea-hypopnea, arousal index, average desaturation, and oxygen desaturation index (ODI). The result of stepwise regression analyses showed that OSAS (p = 0.001) was a risk factor for a low IGF-1 level, independent of age, gender, and body mass index (BMI). Our findings demonstrated that there was a significant negative correlation between IGF-1 and Ln AHI and that OSAS reduced the circulating levels of IGF-1.

Acceptance and long-term compliance of nCPAP in obstructive sleep apnea

In a retrospective cohort study, we evaluated whether improvements in nasal continuous positive airway pressure (nCPAP) technology, particularly the introduction of automatic adjustment of the nCPAP pressure (auto-CPAP), have led to better acceptance and (long-term) compliance in patients with obstructive sleep apnea syndrome (OSAS) as compared to earlier reported data. Questionnaires were sent to 256 patients, who were referred to our clinic for an overnight polysomnography from January 1997 to July 2005 and received nCPAP therapy for OSAS. Of the 256 patients, 24 patients were unavailable for follow-up. Of the remaining 232 patients, 58 patients (25%) had discontinued therapy, while 174 patients (75%) were still using nCPAP after 2 months to 8 years of follow-up. One Hundred and thirty eight (79%) of these 174 patients used nCPAP for at least 4 h/night during >or= 5 nights/week, 82,1% of the conventional nCPAP (fixed pressure CPAP) group (n = 78) and 77,1% of the auto-CPAP group (n = 96). Therefore, including the 58 failures, only 59.5% of patients can be seen as compliant. There were no statistical differences between the fixed pressure CPAP and auto-CPAP users, and between the compliant and non-compliant users according to age, BMI, AHI and Epworth sleepiness scale (ESS). Auto-CPAP patients used significantly more cm H2O. The long-term compliance of nCPAP therapy has have increased only slightly since the introduction of the fixed pressure CPAP 25 years ago, in spite of many efforts to improve it. It seems that a plateau has been reached and that it is unrealistic to aim at a substantially higher compliance rate.

Bench Evaluation of Flow Limitation Detection by Automated Continuous Positive Airway Pressure Device

STUDY OBJECTIVE

Automatic continuous positive airway pressure (CPAP) devices that adjust the pressure delivered to the patient are now available to treat sleep-disordered breathing. Sophisticated auto-CPAP devices can detect and correct flattened inspiratory flow contours (FIFCs) associated with subtle upper airway obstruction. However, evaluations of their performance are made difficult by differences across patients and devices. We performed a bench study of five commercially available auto-CPAP devices using a breath waveform simulator to evaluate sensitivity for detecting flattened inspiratory flow.

DESIGN

Five degrees of FIFC were simulated. In addition, normal and abnormal flow contours from patients published in the literature were evaluated.

MEASUREMENTS AND RESULTS

One device showed autotriggering leading to CPAP increases, and another device varied the CPAP level independently from the presence of an FIFC. The three remaining devices differed regarding the detection of FIFCs and the means used to increase CPAP.

CONCLUSION

Based on the characteristics of each patient, physicians must choose among devices with different thresholds of FIFC detection and different pressure responses to detection. Therefore, physicians need details on the algorithms used in auto-CPAP devices. Manufacturers should supply detailed algorithms.

Combined spinal-propofol anesthesia with noninvasive positive-pressure ventilation

Twenty-three adult patients undergoing repair of inguinal hernia under spinal anesthesia received propofol infusion for sedation with the assist of noninvasive positive-pressure ventilation (NPPV). Circulatory and respiratory parameters, such as percutaneous oxygen saturation, transcutaneous carbon dioxide tension, respiratory rate, tidal volume, blood pressure, and heart rate, were maintained within physiological ranges during the anesthesia. There were no adverse effects. These findings suggest that the application of NPPV in patients receiving propofol infusion for sedation is clinically practicable during anesthesia.

Surgery for obstructive sleep apnoea

BACKGROUND

Obstructive sleep apnoea/hypopnoea syndrome(OSAHS) is the periodic reduction or cessation of airflow during sleep. The syndrome is associated with loud snoring, disrupted sleep and observed apnoeas. Surgery for obstructive sleep apnoea/hypopnoea syndrome aims to alleviate symptoms of daytime sleepiness, improve quality of life, and reduce the signs of sleep apnoea recorded by polysomnography.

OBJECTIVES

The objective of this review was to assess the effects of any type of surgery for the treatment of the symptoms of obstructive sleep apnoea/hypopnoea syndrome in adults.

SEARCH STRATEGY

We searched the Cochrane Airways Group Specialised Register and reference lists of articles. We contacted experts in the field, research dissemination bodies and other Cochrane Review Groups. Searches were current as of July 2005.

SELECTION CRITERIA

Randomised trials comparing any surgical intervention for obstructive sleep apnoea/hypopnoea syndrome with other surgical or non-surgical interventions or no intervention.

DATA COLLECTION AND ANALYSIS

Two reviewers assessed electronic literature search results for possibly relevant studies. Characteristics and data from studies meeting the inclusion criteria were extracted and entered into RevMan 4.2.

MAIN RESULTS

In the 2005 update for this review eight studies (412 participants) of mixed quality met the inclusion criteria. Data from seven studies were eligible for assessment in the review. No data could be pooled. Uvulopalatopharyngoplasty (UPPP) versus conservative management (one trial): An un validated symptom score showed intermittent significant differences over a 12-month follow-up period. No differences in Polysomnography (PSG) outcomes were reported. Laser-assisted uvulopalatoplasty (LAUP) versus conservative management/placebo (two trials): One study recruited mixed a population, and separate data could not be obtained for this trial. In the other study no significant differences in Epworth scores or quality of life reported. A significant difference in favour of LAUP was reported in terms of apnoea hypopnoea index (AHI) and frequency and intensity of snoring. UPPP versus oral appliance (OA) (one trial): AHI was significantly lower with OA therapy than with UPPP. No significant differences were observed in quality of life. UPPP versus lateral pharyngoplasty (lateral PP) (one trial): No significant difference in Epworth scores, but a greater reduction in AHI with lateral PP was reported. Tongue advancement (mandibular osteotomy) + PPP versus tongue suspension + PPP (one trial): There was a significant reduction in symptoms in both groups, but no significant difference between the two surgery types. Complications reported with all surgical techniques included nasal regurgitation, pain and bleeding. These did not persist in the long term. An additional study assessed the effects of four different techniques. No data were available on between group comparisons. Multilevel temperature-controlled radiofrequency tissue ablation (TCRFTA) versus sham placebo and CPAP (one trial): There was an improvement in primary and secondary outcomes of TCRFTA over sham placebo and but no difference in symptomatic improvement when compared with CPAP.

AUTHORS' CONCLUSIONS

There are now a small number of trials assessing different surgical techniques with inactive and active control treatments. The studies assembled in the review do not provide evidence to support the use of surgery in sleep apnoea/hypopnoea syndrome, as overall significant benefit has not been demonstrated. The participants recruited to the studies had mixed levels of AHI, but tended to suffer from moderate daytime sleepiness where this was measured. Short-term outcomes are unlikely to consistently identify suitable candidates for surgery. Long-term follow-up of patients who undergo surgical correction of upper airway obstruction is required. This would help to determine whether surgery is a curative intervention, or whether there is a tendency for the signs and symptoms of sleep apnoea to re-assert themselves, prompting patients to seek further treatment for sleep apnoea.

Annual review of patients with sleep apnea/hypopnea syndrome—a pragmatic randomised trial of nurse home visit versus consultant clinic review

BACKGROUND

This pragmatic randomised, controlled trial investigated annual review of patients with sleep apnea/hypopnea syndrome (SAHS). Clinical outcomes and costs were compared for consultant clinic review versus specialist nurse home visit.

METHOD

One hundred and seventy-four patients were randomised to annual review by consultant clinic appointment or by specialist nurse home visit. SAHS symptoms, Epworth score, hospital anxiety and depression scale (HADS), Short Form-36 (SF-36) and hours of use of constant positive airway pressure (CPAP) were measured before and 3 months after review. The costs and patient preference for review were determined.

RESULTS

After review, both groups significantly increased CPAP use (mean (SD) increase: nurse, 0.66 (1.71) h; consultant, 0.45 (1.69) h) and reduced symptom scores (nurse, -2 (7); consultant, -3 (9)), compared to baseline. There were no differences between groups in these improvements, or in HADS or SF-36 scores. Average duration of a nurse home visit, excluding travel time, was 26 (6) min. Total NHS cost per visit was 52.26 UK pounds (49.85) ($83.62 (79.76)), of which 6.57 UK pounds (1.43) ($10.51 (2.29)) reflected time spent with the patient and the remainder was travel cost. Average duration of consultant review was 10 (6) min, total NHS cost 6.21 UK pounds (3.99) ($9.94 (6.38)). However, the cost to the patient of attending the clinic was 23.63 UK pounds (23.21) ($37.81 (37.13)). Patient preference for review was nurse 16%, consultant 19%, and no preference 65%.

CONCLUSION

Following annual review, use of CPAP increased and symptoms improved. Outcomes were similar for consultant and nurse led review. Home visits were expensive for the healthcare provider, whereas clinic attendance incurred substantial costs to the patient. The majority of patients would accept nurse review for their sleep apnea management.

Can continuous positive airway pressure therapy improve the general health status of patients with obstructive sleep apnea?: a clinical effectiveness study

STUDY OBJECTIVES

To determine the short-term and long-term impacts of continuous positive airway pressure (CPAP) therapy on health-related quality of life (HRQL) in patients with obstructive sleep apnea (OSA).

DESIGN

Prospective longitudinal cohort study.

SETTING

University sleep disorders center.

PATIENTS

Three hundred sixty-five patients with an apnea-hypopnea index (AHI) > or = 20 per hour of sleep and 358 patients with an AHI of < 20.

INTERVENTIONS

All patients with AHIs > or = 20 received CPAP therapy; those with AHIs < 20 did not. The HRQL of all study participants was measured using the 36-item medical outcomes study short form (SF-36) questionnaire at baseline and then at 3 and 12 months of follow-up.

RESULTS

Although the SF-36 scores were similar at baseline, after 3 months of therapy, the CPAP group had higher adjusted emotional summary scores than did those who did not receive CPAP therapy (score increase, 1.72; 95% confidence interval [CI], 0.08 to 3.37). These improvements were maintained for 12 months. The gains in the SF-36 scores were most striking in the vitality domain (score increase, 10.52; 95% CI, 7.04 to 14.00 U increment). The severe OSA group (ie, AHIs > or = 40) experienced the largest benefit. Their adjusted vitality scores were 12.3 U higher (95% CI, 8.0 to 16.6) than those persons without OSA (ie, AHIs < 5).

CONCLUSIONS

CPAP therapy was associated with marked short-term and long-term improvements in the vitality of patients with moderate-to-severe OSA in the community. These findings suggest that CPAP therapy is effective in improving the long-term HRQL of patients with OSA.

Continuous positive airway pressure treatment improves baroreflex control of heart rate during sleep in severe obstructive sleep apnea syndrome

The role of the arterial baroreflex in the cardiovascular changes associated with the obstructive sleep apnea syndrome (OSAS), and the effect of nasal continuous positive airway pressure (CPAP) treatment on baroreflex function during sleep are unknown. Baroreflex control of heart rate was studied in 29 normotensive patients with OSAS under no treatment, in 11 age-matched control subjects, and in 10 patients at CPAP withdrawal after 5.5 +/- 3.7 (range 3-14) months of treatment. Baroreflex control of heart rate was assessed by "sequence method" analysis of continuous blood pressure recordings (Finapres) obtained during nocturnal polysomnography. In untreated OSAS, baroreflex sensitivity (BRS) was low during wakefulness and non-rapid eye movement (REM) stage 2 sleep compared with control subjects, and correlated inversely with mean lowest Sa(O(2)) and the blood pressure increase after apneas. After CPAP treatment, the apnea-hypopnea index was lower, and mean lowest Sa(O(2)) higher than before treatment. After CPAP, patients were more bradycardic, blood pressure and its standard deviation decreased as Sa(O(2)) improved in non-REM stage 2 sleep, and BRS increased (nocturnal wakefulness: +59%; non-REM stage 2 sleep: +68% over pretreatment values). Our data suggest that baroreflex dysfunction in OSAS may be at least partly accounted for by nocturnal intermittent hypoxemia, and can be reversed by long-term CPAP treatment.

Resistive inspiratory muscle training in sleep-disordered breathing of traumatic tetraplegia

OBJECTIVE

To assess the effect of resistive inspiratory muscle training (RIMT) on the static pulmonary function and sleep-induced breathing disorder of individuals with chronic cervical cord injury.

DESIGN

Before-after training.

SETTING

Home-setting training program.

PATIENTS

Fourteen complete traumatic tetraplegic patients (12 men, 2 women; mean age, 41.1 +/- 14y; range, 19-56y) injured for more than 6 months.

INTERVENTION

Subjects participated in a 6-week RIMT program for 15 minutes twice daily at a training intensity of 60% of maximum inspiratory pressure (MIP). The participants were reevaluated at the end of 6-week training.

MAIN OUTCOME MEASURES

Lung volume, peak expiratory flow (PEF), MIP, and maximum expiratory pressure (MEP) were measured by using a spirometry and inspiratory force meter, respectively. Capnography was used to monitor nocturnal pulse oxyhemoglobin saturation (SpO(2)) and end-tidal carbon dioxide tension level (ETCO(2)) of the patients.

RESULTS

The maximum voluntary ventilation (MVV) and MIP of individuals with chronic cervical cord injury substantially improved after RIMT. MIP increased from -68.7 +/- 27.4cmH(2)O to -77.3 +/- 24.0cmH(2)O and MVV rose from 62.7 +/- 33.2L to 73.4 +/- 31.3L (P <.05). Despite increasing from 3.5 +/- 1.8L/s to 4.0 +/- 1.7L/s, PEF was statistically insignificant. For the individuals with improved MIP, the duration of ETCO(2) greater than 48mmHg reduced from 2.2% +/- 3.3% to 1.0% +/- 2.0% of total sleep time (P =.05) and that of SpO(2) less than 90% significantly declined from 1.8% +/- 2.8% to 1.3% +/- 2.4% of total sleep time (P <.05).

CONCLUSION

These findings suggest that RIMT can enhance the respiratory muscle strength and endurance of chronic tetraplegia and further ameliorate the sleep-induced breathing disorder. Therefore, RIMT is suggested as a home program for patients with sleep-disordered breathing.

Sleep structure correlates of continuous positive airway pressure variations during application of an autotitrating continuous positive airway pressure machine in patients with obstructive sleep apnea syndrome

STUDY OBJECTIVES

To evaluate the relationship between sleep structure and continuous positive airway pressure (CPAP) delivered by an automatic CPAP (auto-CPAP) machine in patients with obstructive sleep apnea syndrome (OSAS).

DESIGN

Nocturnal polysomnography was performed during CPAP administration by an auto-CPAP machine (Autoset Clinical 1; ResMed; Sydney, Australia).

SETTING

Sleep-disorders center in a research institute.

PATIENTS

Fifteen subjects with newly diagnosed OSAS deserving home CPAP treatment.

MEASUREMENTS AND RESULTS

During the night, in most cases, the lowest CPAP level was recorded during a prolonged nonrapid eye movement (NREM) sleep period uninterrupted by arousals, whereas the highest level during wake-sleep transitions or NREM sleep fragmented by arousals. In four subjects, rapid eye movement sleep was always associated with increasing CPAP. Sleep efficiency was negatively correlated with CPAP variability, evaluated as the SD of the mean nocturnal CPAP level averaged epoch by epoch (r = 0.63, p < 0.02). Eighty-eight percent of rapid CPAP augmentations (increases by at least 2 cm H(2)O in less-than-or-equal 2 min) were observed during sleep-wake transitions or after arousals/awakenings (Ar/Aw); 63% of such Ar/Aw were not preceded by any detectable respiratory abnormality.

CONCLUSIONS

CPAP levels and variations during auto-CPAP application may be mainly related to sleep continuity and efficiency. The recording of a highly variable pressure during auto-CPAP administration in an unattended environment must raise the question whether the patient's sleep quality was acceptable. A poor sleep quality during an autotitration night could lead to an undesirable overestimation of the CPAP level needed for use with fixed-level CPAP machines.

Application of nasal bi-level positive airway pressure to respiratory support during combined epidural-propofol anesthesia

STUDY OBJECTIVE

To examine whether nasal bi-level positive airway pressure (BiPAP) can be used as an airway during combined epidural-propofol anesthesia.

DESIGN

Prospective, consecutive case series study.

SETTING

Operating room at a general hospital.

PATIENTS

213 ASA physical status I and II adult patients undergoing lower extremity or lower abdominal gynecology surgery.

INTERVENTIONS

After epidural anesthesia, propofol was infused at 20 mg/kg/hr (P20) for 4 to 5 minutes followed by 5 mg/kg/hr (P5), and nasal continuous positive airway pressure (CPAP) 8 cm H(2)O and BiPAP 14/8 cm H(2)O was applied. In clinical situations, BiPAP with respiratory rate (RR) 10 breaths/min was applied. Furthermore, tidal volume (V(T)) during anesthesia, the effect of changing pressure support levels, and evaluation of pressure-controlled ventilation without spontaneous breathing were examined.

MEASUREMENTS AND MAIN RESULTS

CPAP resulted in a high RR, marked increased PaCO(2), and slightly decreased PaO(2), whereas BiPAP showed no change or a slightly decreased RR, slightly increased PaCO(2), and no change in PaO(2) or a great increase in PaO(2) with oxygen delivery. In clinical applications, similar results were found and anesthetic conditions were sufficient. Tidal volume increased after induction and maintained increased values under BiPAP 14/8 cm H(2)O. Of V(T) at 2, 6, or 10 cm H(2)O of pressure support levels, the 6 cm H(2)O was appropriate. Vecuronium injection showed a slight decrease and then increase in V(T) and PaCO(2), but the values were within normal (safe) limits. Respiration after rapid and high-dose infusion of propofol showed a markedly decreased RR, but the V(T) was maintained, and PaCO(2) and PaO(2) were at safe values. Rapid induction with 2.0 mg/kg propofol followed by P5 showed satisfactory results, in all but the obese patients.

CONCLUSIONS

BiPAP 14/8 cm H(2)0 with RR at 10 breaths/min during combined epidural-propofol anesthesia can be used to provide ventilatory support in lower extremity or lower abdominal gynecology surgery.

Long-Term Results of Tracheostomy for Severe Obstructive Sleep Apnea Syndrome

Severe obstructive sleep apnea (OSAS) is most often accompanied by metabolic syndrome, obesity, diabetes and coronary disease. In its most severe form, it is a life-threatening condition, requiring active and immediate help. Nasal continuous positive airway pressure (CPAP) is the most efficient nonsurgical treatment for patients with OSAS. However, for anatomical, disease-related and subjective reasons, many patients cannot accept this treatment. A permanent tracheostomy may be one alternative in such patients who, in addition, often suffer from extreme obesity and severe heart disease. In this paper, we describe the long-term follow-up results of 7 patients suffering from OSAS and treated with permanent tracheostomy. All the patients (5 men, 2 women) were diagnosed using the static charge sensitive bed method and night-time oximetry for sleep analysis. The mean body mass index (BMI) of the patients ranged from 34 to 60 and the age from 41 to 64 years. All the patients had severe OSAS and long periods of low oxygen saturation (SaO2) levels. Six patients had a CPAP trial before tracheostomy. Only 2 patients tolerated the trial but, despite the continuous use of CPAP, they were nonresponders. Permanent tracheostomy was done according to normal routine in each patient. After primary healing of 2 days, they used silver cannulae, which also allowed them to speak. The patients were evaluated every year after the tracheostomy. After some practical difficulties including proper maintenance of the cannula, all the patients quickly learned the correct management. In postoperative sleep studies, nadir SaO2 levels had improved significantly, obstructive apneas had disappeared and the subjective quality of life had improved. No marked changes in BMI were found.

Constant vs. automatic continuous positive airway pressure therapy: home evaluation

STUDY OBJECTIVES

To compare the efficacy and patient tolerance, compliance, and preference between auto-continuous positive airway pressure (CPAP) and constant CPAP.

DESIGN

Single-blinded, crossover, cohort study of consecutive patients with obstructive sleep apnea syndrome, with two treatment periods of 2 months each.

PATIENTS

Twenty-five patients (22 men, 3 women) with sleep apnea syndrome confirmed by ambulatory polysomnography.

MEASUREMENTS AND INTERVENTIONS

After baseline polysomnography, patients underwent in-laboratory polysomnography for titration of constant CPAP. The order of treatment was randomly allocated, either auto-CPAP and then constant CPAP, or vice versa. The auto-CPAP pressure range was 6 to 16 cm H(2)O. At the end of each 2-month period, patients underwent a control ambulatory polysomnography and received a questionnaire on subjective well-being and device evaluation. Duration of use was checked through CPAP device monitoring.

RESULTS

No differences were found in apnea/hypopnea index (constant CPAP, 9.7+/-1.9 events/h vs auto-CPAP, 10.6+/-9.3 events/h), awakening/arousal index (constant CPAP, 13.7 +/- 8.0 events/h vs auto-CPAP, 15.5 +/- 8.9 events/h), slow-wave sleep duration, nocturnal saturation, or complaint of daytime sleepiness. The mean pressure required was significantly lower during auto-CPAP than during constant CPAP (8.8+/-1.8 cm H(2)O vs. 9.7+/-2.6 cm H(2)O, respectively). Patient tolerance, compliance, and duration of use were similar with both treatments.

CONCLUSIONS

Auto-CPAP is as effective as constant CPAP. A wide pressure range for auto-CPAP can be used in all patients, suggesting that, in the future, use of a broad pressure range in the auto-CPAP mode could obviate the need for the titration night.

Nasopharyngeal symptoms in patients with obstructive sleep apnea syndrome. Effect of nasal CPAP treatment

BACKGROUND

Nasal side effects are often reported during nasal continuous positive airway pressure (CPAP) treatment of obstructive sleep apnea syndrome (OSAS) and may make the use of nasal CPAP difficult.

OBJECTIVE

The aim of this study was to evaluate the effect of nasal CPAP on nasopharyngeal symptoms in OSAS patients.

METHODS

The frequency and severity of nasopharyngeal symptoms and signs were prospectively evaluated in 49 consecutive OSAS patients (37 men, 12 women, mean (SD) age 54 (7) years, body mass index 35 (6) kg/m2) immediately before and after 6 months' treatment with nasal CPAP.

RESULTS

Nasopharyngeal symptoms were common already before starting nasal CPAP: 74% of patients reported dryness, 53% sneezing, 51% mucus in the throat, 45% blocked nose, and 37% rhinorrhea. During nasal CPAP treatment, severity and frequency of sneezing (75%) and rhinorrhea (57%) increased. This increase was related to the season when nasal CPAP was applied, and was more profound in winter than in summer. Mild abnormalities on rhinoscopy and paranasal sinus X-rays were common both at baseline and at follow-up with no significant change during treatment.

CONCLUSIONS

Nasopharyngeal problems were found to be frequent in patients with OSAS before nasal CPAP treatment, and tended to increase during the treatment.

Dentistry's role in the diagnosis and co-management of patients with sleep apnoea/hypopnoea syndrome

The sleep apnoea/hypopnoea syndrome (SAHS) is characterized by repeated upper airway narrowing or collapse during sleep. The obstruction is caused by the soft palate and/or base of tongue collapsing against the pharyngeal walls because of decreased muscle tone. These episodes are accompanied by hypoxaemia, surges in blood pressure, brief arousal from sleep and pronounced snoring. Individuals with occult disease are at heightened risk of motorway accidents because of excessive sleepiness, sustained hypertension, myocardial infarction, and stroke. The signs and symptoms of SAHS may be recognisable in the dental practice. Common findings in the medical history include daytime sleepiness, snoring, hypertension, and type 2 diabetes mellitus. Common clinical findings include male gender, obesity, increased neck circumference, excessive fat deposition in the palate, tongue (macroglossia) and pharynx, a long soft palate, a small recessive mandible and maxilla, and calcified carotid artery atheromas on panoramic and lateral cephalometric radiographs. Dentists who recognise these signs and symptoms have an opportunity to diagnose patients with occult SAHS. After confirmation of the diagnosis by a physician, dentists can participate in the management of the disorder by fabricating mandibular advancement appliances that enlarge the retroglossal space by anterior displacement of the tongue and performing corrective upper airway surgery that prevents recurrent airway obstruction.

Long-term results of uvulopalatopharyngoplasty for obstructive sleep apnea syndrome

OBJECTIVES

Assessment of the long-term effect of uvulopalatopharyngoplasty (UPPP) on snoring, excessive daytime sleepiness, and nocturnal oxygen desaturation index (ODI) in patients with obstructive sleep apnea syndrome.

STUDY DESIGN

Evaluation of snoring, excessive daytime sleepiness, and ODI in patients treated by UPPP earlier.

MATERIALS AND METHODS

Patients (n = 58) with a follow-up period of 11 to 74 months (median, 34 mo) were included in this study. Snoring and excessive daytime sleepiness were scored on specially designed semiquantitative scales. In all patients ODI was calculated from pulse-oximetry combined with polysomnography at base line and by polygraphy (MESAM 4) during follow-up in 38 patients. Long-term response was compared with 6-month response in the same cohort.

RESULTS

There was a long-term improvement of snoring in 63% of patients, no change in 23%, and a deterioration in 14% (P < .00001). Overall snoring increased slightly between 6 months and long-term follow-up. There was an improvement of excessive daytime sleepiness in 38%, no change in 27%, and a deterioration in 35% (P = .80). Excessive daytime sleepiness showed a relapse to preoperative levels between 6 months and long-term follow-up. The median improvement of ODI was -1 (95% interpercentile range, 73-51) and was not significant (P = .35). In 5 of 13 patients in whom ODI at baseline exceeded 20, ODI was reduced to less than 20. In 4 of the 38 patients ODI was reduced to less than 5. The improvement of ODI decreased significantly between 6 months and long-term follow-up (P = .03). No relation was found between body mass index, Mueller maneuver, X-cephalometry, and long-term outcome. An additional finding was that the ODI decreased after UPPP in combination with tonsillectomy, compared with a slight increase after UPPP alone; the difference was significant (P = .008).

CONCLUSION

The response to UPPP for obstructive sleep apnea syndrome decreases progressively over the years after surgery. UPPP in combination with tonsillectomy was more effective than UPPP alone.

Surgery for obstructive sleep apnoea

BACKGROUND

Obstructive sleep apnoea is the periodic reduction (hypopnoea) or cessation (apnoea) of airflow during sleep. The syndrome is associated with loud snoring, disrupted sleep and observed apnoeas. Beside conservative treatments there are a range of 8 broad categories of operative treatments for this condition. Surgical treatments aim to relieve the obstruction by either increasing the surface area

OBJECTIVES

Surgery for obstructive sleep apnoea aims to relieve the obstruction by increasing the surface area of the airway, bypassing the pharyngeal airways or removing a lesion. The objective of this review was to assess the effects of any type of surgery for the treatment of obstructive sleep apnoea.

SEARCH STRATEGY

We searched the Cochrane Airways Group trials register and reference lists of articles. We contacted experts in the field, research dissemination bodies and other Cochrane Review Groups.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing any surgical intervention for obstructive sleep apnoea with other surgical or non-surgical interventions for obstructive sleep apnoea or no intervention.

DATA COLLECTION AND ANALYSIS

No completed trials were identified.

MAIN RESULTS

No studies fulfilled the inclusion criteria.

REVIEWER'S CONCLUSIONS

There is an urgent need for high quality randomised controlled trials to be carried out in the field of surgery for obstructive sleep apnoea. More research should also be undertaken to identify and standardise techniques to determine the site of airways obstructions.

Nasopharyngeal symptoms and nasal continuous positive airway pressure therapy in obstructive sleep apnoea syndrome

Nasal problems are often reported during the treatment of obstructive sleep apnoea syndrome (OSAS) with nasal continuous positive airway pressure (nCPAP) and may jeopardize the use of nCPAP. This retrospective study evaluated the frequency of nasopharyngeal symptoms in OSAS patients before and during nCPAP treatment. A questionnaire was sent to all patients (n = 194) with OSAS for whom nCPAP had been prescribed during the years 1990-1995 at the authors' hospital, enquiring about nasopharyngeal symptoms both before and during treatment and nCPAP use. The study population consisted of the 151 patients [128 men and 23 women, median (range) age 54 (31-76) years and body-mass index 34 (17-54) kg/m2] who responded to the questionnaire. Seventy-one percent of patients were still using nCPAP after a median treatment duration of 30 months. The most commonly reported nasopharyngeal symptoms were nasal stuffiness, which was reported by 46% of patients before nCPAP and by 37% during nCPAP, dry nose (39% before and 46% during nCPAP), sneezing (36% and 35%) and rhinorrhoea (21% and 27%). The frequency of nasopharyngeal symptoms did not change with nCPAP treatment. The frequency of nasopharyngeal symptoms before and during nCPAP treatment was similar in those patients who discontinued the treatment (n = 44, 29%) compared with those who continued with nCPAP (n = 107, 71%). Skin problems caused by the mask (50%), airleak from mouth (44%), difficulty in exhaling (29%) and a sensation of suffocation (26%) were also problems associated with nCPAP treatment. Nasopharyngeal symptoms were common in patients with OSAS before nCPAP was started. There was no significant change in the frequency of these symptoms during nCPAP treatment. Nasopharyngeal symptoms did not seem to affect treatment continuation.

Effects of nasal continuous positive airway pressure on pulmonary haemodynamics and tissue oxygenation in patients with obstructive sleep apnoea

We investigated the acute effects of nasal continuous positive airway pressure (CPAP) on pulmonary haemodynamics and tissue oxygenation in eight men with obstructive sleep apnoea (OSA) by means of right heart catheterization. They were tested at four dosage levels of nasal CPAP: 0, 5, 10, and 15 cmH2O. Nasal CPAP significantly reduced the cardiac index at the 10 and 15 cmH2O doses. The mean pulmonary artery pressure was significantly elevated with 10 and 15 cmH2O, and pulmonary capillary wedge pressure was significantly increased with 15 cmH2O of nasal CPAP. Pulmonary vascular resistance was significantly increased with 10 cmH2O of nasal CPAP. The 5 cmH2O dose of nasal CPAP did not affect significantly these parameters. Mixed venous oxygen tension was unchanged at any pressure. We conclude that tissue oxygenation was maintained in the OSA patients during administration of nasal CPAP, even though a high CPAP clearly affected pulmonary haemodynamics.

Respiratory aspects of neurological disease

Neurological disease may result in respiratory dysfunction; however the manifestations of respiratory dysfunction in such patients may be atypical because of wider effects of their underlying condition. In the present review we have considered separately acute neuromuscular respiratory disease (as well as aspects of respiratory muscle function relevant to intensive care), chronic neuromuscular respiratory disease, sleep related disorders, respiratory consequences of specific neurological diseases, and neurological features of respiratory disease. Approaches to specific clinical problems are discussed; in many instances this can be expedited by close cooperation with a respiratory physician. We suggest that management of respiratory dysfunction in neurological disease depends critically on three factors: firstly, knowledge of when respiratory dysfunction is likely to occur; secondly, maintaining a high index of clinical suspicion (specifically apparently vague symptoms should not be uncritically attributed to the underlying neurological condition); and, thirdly, the pursuing of appropriate investigations.

Evaluation of an auto-CPAP device for treatment of obstructive sleep apnoea

BACKGROUND

Auto-CPAP machines used in the treatment of obstructive sleep apnoea (OSA) are designed to vary the treatment pressure automatically in order always to apply the actually needed pressure. Consequently they should be able to achieve at least identical therapeutic effects as conventional constant pressure CPAP with a lower mean treatment pressure. The present study was designed to evaluate the therapeutic efficacy and the treatment pressure of an auto-CPAP machine (REM + auto, SEFAM) in comparison with a conventional CPAP device.

METHODS

Following CPAP titration, 16 patients with OSA were allocated to receive conventional CPAP and auto-CPAP treatment under polysomnographic control in a randomised order. After each treatment the patients were asked to assess the therapy using a questionnaire; a vigilance test was also carried out and subjective daytime sleepiness was evaluated using the Epworth Sleepiness Scale (ESS).

RESULTS

The mean (SD) apnoea/hypopnoea index (AHI) during auto-CPAP treatment was comparable with that during conventional CPAP treatment (4.2 (5.1) versus 3.6 (4.0)). Neither an analysis of sleep architecture nor the arousal index (7.4 (4.1) versus 7.0 (4.3)) revealed any significant differences. Daytime sleepiness measured with the ESS was also comparable (5.3 (3.4) versus 6.5 (4.2)). The vigilance test showed normal values after both treatments in all patients with no significant differences. The mean pressure during auto-CPAP treatment (8.1 (2.9) mbar), however, was significantly higher than that employed in conventional CPAP treatment (7.6 (2.7) mbar; mean difference 0.5 mbar; 95% CI 0.1 to 0.9 mbar; p < 0.05).

CONCLUSIONS

Auto-CPAP was equally as effective as conventional CPAP with respect to therapeutic efficacy. The aim of reducing the treatment pressure with auto-CPAP, however, was not achieved.

Decreasing surgical risks for patients with obstructive sleep apnea

The prevalence of obstructive sleep apnea (OSA) has only recently been appreciated, in part because the signs and symptoms of OSA were previously overlooked. The identification of this disorder is extremely important before surgery to allow appropriate airway management. This article presents a brief overview of sleep apnea, its symptoms, and potential consequences. Nursing interventions are given for the preoperative, intraoperative, and postoperative phases. A resource list of agencies and internet sites that reference OSA is included for additional information.

Nocturnal body movements and hypoxemia in middle-aged females after lower abdominal surgery under general anesthesia: a study with the static-charge-sensitive bed (SCSB)

OBJECTIVE

The aim of this study was to evaluate the feasibility of the static-charge-sensitive-bed (SCSB) combined with pulse oximetry (SpO2) for postoperative monitoring and to determine variables which could be used for evaluating the quality of postoperative sleep and breathing.

METHODS

The frequency of body movements and the perioperative breathing abnormalities were assessed using the SCSB and pulse oximeter in 15 female ASA-class I-II patients undergoing elective lower abdominal surgery under general anesthesia. Anesthesia and control of postoperative pain followed standard practice. The patients were monitored during one preoperative and three consecutive postoperative nights. Movements were analyzed according to their duration and time interval. The effect of opioids was evaluated by measuring arterial oxyhemoglobin saturation (SpO2) with pulse oximetry for one hour before and two hours after administration of standard doses of oxycodone.

RESULTS

The total movement time per hour increased during the first postoperative night (p = 0.003). Conversely, periodic movement activity decreased significantly during the three postoperative nights (p = 0.05, p < 0.001, p = 0.007). The mean SpO2 decreased during the first postoperative night (95.5% vs. 94.2%, p = 0.002), but returned to the preoperative level during the following nights. No episodes of apnea with significant oxygen desaturation (a decrease in SpO2 > 5%) were observed. Opioid administration was associated with decreased mean SpO2 (94.8% vs. 93.6%, p = 0.02), but did not lead to clinically significant hypoxemia (lowest observed SpO2 89.8%).

CONCLUSIONS

Postoperative periodic movement activity was suppressed, but sleep remained fragmented with frequent body movements. In our middle-aged non-obese females (ASA I-II), no severe postoperative hypoxemia was observed during the three-nights postoperative survey. Perioperative movement monitoring with the SCSB was a valuable tool in rejecting movement artefacts of SpO2 and in evaluating general sleep quality.

Positional vs nonpositional obstructive sleep apnea patients: anthropomorphic, nocturnal polysomnographic, and multiple sleep latency test data

STUDY OBJECTIVES

To compare anthropomorphic, nocturnal polysomnographic (PSG), and multiple sleep latency test (MSLT) data between positional (PP) and nonpositional (NPP) obstructive sleep apnea (OSA) patients.

DESIGN

This is a retrospective analysis of anthropomorphic, PSG, and MSLT data of a large group of OSA patients who underwent a complete PSG evaluation in our sleep disorders unit. The patients were divided in two groups: the PP group, those patients who had a supine respiratory disturbance index (RDI) that was at least two times higher than the lateral RDI, and the NPP group, those patients in whom the RDI in the supine position was less than twice that in the lateral position.

SUBJECTS

From a group of 666 consecutive OSA patients whose conditions were diagnosed in our unit from September 1990 to February 1995, 574 patients met the following criteria and were included in the study: RDI > 10; age > 20 years, and body mass index (BMI) > 20.

RESULTS

Of all 574 patients, 55.9% were found to be positional. No differences in height were observed but weight and BMI were significantly higher in the NPP group, these patients being on the average 6.5 kg heavier than those in the PP group. The PP group was, on average, 2 years younger than the NPP group. Nocturnal sleep quality was better preserved in the PP group. In this group, sleep efficiency and the percentages of deep sleep (stages 3 and 4) were significantly higher while the percentages of light sleep (stages 1 and 2) were significantly lower than in the NPP group. No differences for rapid eye movement (REM) sleep were found. In addition, wakefulness after sleep onset and the number of short arousals (< 15 s) were significantly lower in the PP group. Apnea index and total RDI were significantly higher and the minimal arterial oxygen saturation in REM and non-REM sleep was significantly lower in the NPP. No differences in periodic limb movements data were found between the two groups. The average MSLT was significantly shorter in the NPP group. Univariate and multivariate stepwise logistic regression analysis showed that the most dominant variable that correlates with positional dependency in OSA patients is RDI, followed by BMI which also adds a significant contribution to the prediction of positional dependency. Age, although significant, adds only a minor improvement to the prediction of this positional dependency phenomenon. A severe, obese, and older OSA patient is significantly less likely to be positional than a mild-moderate, thin, and young OSA patient. In four obese OSA patients who lost weight, a much more pronounced reduction was seen in the lateral RDI than in the supine RDI, and three of these cases who were previously NPP became PP.

CONCLUSIONS

In a large population of OSA patients, most were found to have at least twice as many apneas/hypopneas in the supine than in the lateral position. These so-called "positional patients" are on the average thinner and younger than "nonpositional patients." They had fewer and less severe breathing abnormalities than the NPP group. Consequently their nocturnal sleep quality was better preserved and, according to MSLT data, they were less sleepy during daytime hours. RDI was the most dominant factor that could predict the positional dependency followed by BMI and age. RDI showed a threshold effect, the prevalence of PP in those with severe RDI (RDI > or = 40) was significantly lower than in those OSA patients with mild-moderate RDI. BMI showed a major significant inverse relationship with positional dependency, while age had only a minor although significant inverse relationship with it. Body position during sleep has a profound effect on the frequency and severity of breathing abnormalities in OSA patients.

Obstructive sleep apnea and related disorders

OSAS, a common cause of disrupted sleep and EDS, result from repetitive closure of the upper airway during sleep. It probably represents the most severe syndrome related to obstruction of the upper airway; less severe forms include UARS, a syndrome characterized by the need for increased effort to breath but no prominent apneas or hypopneas, and primary snoring. Initial clues to the presence of OSAS and related disorders are derived from the history and include loud snoring, EDS or insomnia, and witnessed apneas. Some patients, especially women, may complain mostly of tiredness or fatigue, and children may present with behavioral abnormalities. Obesity, a large neck circumference, and a crowded oropharynx are common on physical examination. Nonobese patients, in particular, often have retrognathia, a high-arched narrow palate, macroglossia, enlarged tonsils, temporomandibular joint abnormalities, or chronic nasal obstruction. The clinical suspicion of obstructed nocturnal breathing is confirmed by overnight polysomnography, and an MSLT may be used to assess sleepiness. Esophageal manometry during polysomnography facilitates diagnosis of UARS. Treatment most commonly consists of nasal CPAP or BPAP, although problems with compliance make surgical treatment preferable in some cases. Although UPPP eliminates sleep apnea only in a minority of patients, combining UPPP with maxillofacial procedures appears to improve outcomes. Other treatments such as the use of dental appliances or medications, weight loss, and positional therapy may be useful as adjunctive therapy for moderate to severe OSAS or as primary treatments for UARS or mild OSAS.

Electrophysiologic evaluation of sinus node function and atrioventricular conduction in patients with prolonged ventricular asystole during obstructive sleep apnea

In 15 patients with ventricular asystole of 8.5 +/- 3.5 seconds (range 5.0 to 16.8) occurring exclusively during obstructive sleep apnea, electrophysiologic study of sinus node function and atrioventricular conduction before and after administration of intravenous atropine (0.02 mg/kg) was performed. Electrophysiologic parameters of sinus node function were normal in 12 of 15 patients (80%) and atrioventricular (AV) nodal function was normal in 7 patients (47%). Almost all abnormal findings of sinus node function and AV nodal function were reversible by administration of atropine. The HisPurkinje system function was normal in 6 patients (40%). Prolonged HV intervals (57 to 73 ms) were found in 9 patients (60%). Intra- or infra-His block was not observed in any patient. In summary, electrophysiologic parameters of sinus node function and AV conduction were normal or only slightly abnormal in all 15 study patients, which suggests that prolonged ventricular asystole during obstructive sleep apnea is not due to fixed or anatomic disease of the sinus node or the AV conduction system.

Accuracy of an intelligent CPAP machine with in-built diagnostic abilities in detecting apnoeas: a comparison with polysomnography

BACKGROUND

In patients with sleep apnoea early diagnostic evaluation and treatment may be delayed due to limited access to full polysomnography (PSG). For "typical" patients, simplified strategies are needed. A study was performed to evaluate the accuracy of a new continuous positive airway pressure (CPAP) device with in-built diagnostic abilities (Autoset) in detecting apnoeas.

METHODS

Twenty seven patients underwent full overnight polysomnography. Data with the Autoset were acquired simultaneously. Standard nasal prongs were used. Apnoeas were detected by special analysis of the flow signal. As the Autoset derives all its data from one signal, careful examination of the raw data is important to assess the quality of the flow signal.

RESULTS

There was a correlation between the apnoea index (AI) assessed by the Autoset (AI-Autoset) and by polysomnography AI-PSG (r = 0.85) and between the AI-Autoset and the apnoea/hypopnoea index (AHI) during polysomnography (r = 0.87). The Autoset identified patients with an AHI-PSG of > 20 (a level of respiratory disturbance that would warrant consideration for treatment in most centres for sleep disorders) with a sensitivity of 82% and a specificity of 90%.

CONCLUSIONS

The good correlation between the apnoea index measured by the Autoset and by polysomnography, and the high sensitivity in detecting patients with an AHI of > 20, may make the Autoset a valuable tool for the management of typical patients with sleep apnoea. However, very low values for nasal ventilation on the printout raises the suspicion of poor signal quality and misleading results.

Treatment of sleep apnoea in spinal cord injured patients

Little is known about sleep disorders in spinal cord injured (SCI) patients. Three SCI patients who reported severe daytime sleepiness and sleep complaints were evaluated with nocturnal polysomnography and oxygen saturation with pulsoximeter on several occasions at home. In addition respiratory registration was preformed during overnight stay in the hospital. Two patients who had sleep apnoea episodes with reduced oxygen saturation during sleep were treated with continuous positive airway pressure with good results on sleep architecture, oxygen saturation, and daytime sleepiness. One obese patient was advised to lose weight and to reduce smoking and alcohol consumption, and following this advice his sleep related problems were reduced with no further treatment necessary. It is suggested that SCI patients who complain about sleep related disorders should be appropriately screened, with inclusion of nocturnal polysomnography, oxygen saturation, and respiratory registration and, depending on the screening results, appropriate advice/treatment applied.

Wrist actigraphic assessment of sleep in 116 community based subjects suspected of obstructive sleep apnoea syndrome

BACKGROUND

The combined use of wrist actigraphic assessment and self assessment of sleep in the screening of obstructive sleep apnoea syndrome was evaluated in a community based sample.

METHODS

One hundred and sixteen community based subjects clinically suspected of having obstructive sleep apnoea (syndrome) were evaluated by means of simultaneous ambulatory recording of respiration (oronasal flow thermistry), motor activity (wrist actigraphy), and subjective sleep (sleep log) during one night of sleep.

RESULTS

The subjects were distributed according to their apnoea index (AI); AI < 1 (non-apnoeic snorers) 44%; AI 1- < 5 39%; and AI > or = 5 17%. High apnoea index values were associated with self reported disturbed sleep initiation and more fragmented and increased levels of motor activity and decreased duration of immobility periods, particularly in those with an apnoea index of > or = 5. Across subjects the duration of immobility periods was the only predictor of the apnoea index, explaining 11% of its variance. Use of the multiple regression equation to discriminate retrospectively between those with an apnoea index of < 1 and > or = 5 resulted in sensitivity and specificity values of 75% and 43%, and 5% and 100%, respectively.

CONCLUSIONS

The combined use of a sleep log and actigraphic assessment of sleep failed to identify reliably those subjects who suffered from obstructive sleep apnoea (syndrome) in a sample of community based subjects reporting habitual snoring combined with excessive daytime sleepiness and/or nocturnal respiratory arrests.