Perioperative Continuous Positive Airway Pressure Therapy: A Review With the Emphasis on Randomized Controlled Trials and Obstructive Sleep Apnea.

The perioperative use of continuous positive airway pressure (CPAP) therapy has increased substantially in recent years, particularly in relationship to the treatment of patients with known or suspected obstructive sleep apnea (OSA). OSA is common in the surgical population and is reported as an independent risk factor for postoperative complications, intensive care unit admission, and increased length of hospital stay. A large proportion of OSA patients are undiagnosed at the time of surgery and can therefore not be optimized preoperatively. Nowadays, golden standard treatment of moderate to severe OSA is nightly CPAP at home, often with an autotitration mode. Unfortunately, there are only a handful of randomized clinical trials investigating the effect of preoperative and/or postoperative CPAP treatment in OSA patients, so the perioperative guidelines are based on a combination of randomized clinical trials, observational studies, case studies, and expert opinions. In this review, we have summarized the current evidence regarding the use of perioperative CPAP therapy with an emphasis on patients with OSA. We identified 21 randomized, controlled trials that investigated the effect of CPAP on postoperative physiology and complications in surgical patients. Our review reveals evidence, suggesting that CPAP after surgery improves oxygenation and reduces the need for reintubation and mechanical ventilation after surgery. It is also evident that CPAP reduces apnea and hypopnea frequency and related hypoxemia after surgery. Poor adherence to CPAP in the perioperative setting is a limiting factor in assessing its potential to optimize postoperative cardiorespiratory outcomes. Studies of postoperative outcomes in patients who have previously been prescribed CPAP for OSA and are therefore familiar with its use could help to address this shortcoming, but they are unfortunately lacking. This shortcoming should be addressed in future studies. Furthermore, many of the studies of the postoperative effect of CPAP in OSA patents are small, and therefore, single-center studies and larger randomized, controlled multicenter studies are warranted.

Hypoxic ventilatory response after rocuronium-induced partial neuromuscular blockade in men with obstructive sleep apnoea.

Obstructive sleep apnoea and residual neuromuscular blockade are, independently, known to be risk factors for respiratory complications after major surgery. Residual effects of neuromuscular blocking agents are known to reduce the hypoxic ventilatory response in healthy volunteers. Patients with obstructive sleep apnoea have impaired control of breathing, but it is not known to what extent neuromuscular blocking agents interfere with the regulation of breathing in such patients. In a physiological study in 10 unsedated men with untreated obstructive sleep apnoea, we wished to examine if partial neuromuscular blockade had an effect on hypoxic ventilatory response (isocapnic hypoxia to oxygen saturation of 80%) and hypercapnic ventilatory response (normoxic inspired carbon dioxide 5%). The hypoxic ventilatory response was reduced by 32% (p = 0.016) during residual neuromuscular block (rocuronium to train-of-four ratio 0.7), but the hypercapnic ventilatory response was unaffected. We conclude that neuromuscular blockade specifically depresses peripheral chemosensitivity, and not respiratory muscle function since the hypercapnic ventilatory response was unaffected.

Clinical markers of asthma and IgE assessed in parents before conception predict asthma and hayfever in the offspring.

BACKGROUND: Mice models suggest epigenetic inheritance induced by parental allergic disease activity. However, we know little of how parental disease activity before conception influences offspring's asthma and allergy in humans. OBJECTIVE: We aimed to assess the associations of parental asthma severity, bronchial hyperresponsiveness (BHR), and total and specific IgEs, measured before conception vs. after birth, with offspring asthma and hayfever. METHODS: The study included 4293 participants (mean age 34, 47% men) from the European Community Respiratory Health Survey (ECRHS) with information on asthma symptom severity, BHR, total and specific IgEs from 1991 to 1993, and data on 9100 offspring born 1972-2012. Adjusted relative risk ratios (aRRR) for associations of parental clinical outcome with offspring allergic disease were estimated with multinomial logistic regressions. RESULTS: Offspring asthma with hayfever was more strongly associated with parental BHR and specific IgE measured before conception than after birth [BHR: aRRR = 2.96 (95% CI: 1.92, 4.57) and 1.40 (1.03, 1.91), respectively; specific IgEs: 3.08 (2.13, 4.45) and 1.83 (1.45, 2.31), respectively]. This was confirmed in a sensitivity analysis of a subgroup of offspring aged 11-22 years with information on parental disease activity both before and after birth. CONCLUSION & CLINICAL RELEVANCE: Parental BHR and specific IgE were associated with offspring asthma and hayfever, with the strongest associations observed with clinical assessment before conception as compared to after birth of the child. If the hypothesis is confirmed in other studies, parental disease activity assessed before conception may prove useful for identifying children at risk for developing asthma with hayfever.

Effect of an elastic girdle on lung function, intra-abdominal pressure, and pain after midline laparotomy: a randomized controlled trial.

PURPOSE: Girdles and abdominal binders may reduce pain and stabilize the abdominal wall after laparotomy, but a risk for increased intra-abdominal pressure and decreased lung function is also hypothesized. The aim of this study was to investigate the effect of an abdominal girdle after midline laparotomy in a randomized controlled trial. METHODS: Twenty-three patients undergoing laparotomy were randomized to wear an elastic girdle postoperatively and 25 were randomized to no girdle. Pulmonary function was evaluated with; forced vital capacity (FVC), forced expiratory volume during one second (FEV1), peak expiratory flow (PEF), and cough PEF. Pain was recorded using a visual analog scale (VAS). All patients completed the ventral hernia pain questionnaire (VHPQ) before surgery and at the end of the study. Intra-abdominal pressure was measured via an indwelling urinary catheter. Wound healing was assessed from photographs. RESULTS: FVC, FEV1, PEF, and cough PEF were reduced by about 30 % after surgery, but there were no differences between patients with or without a girdle (ANOVA). Intra-abdominal pressure and wound healing were the same in both groups. Pain was significantly lower on day 5 in the girdle group (p = 0.004). CONCLUSIONS: An individually fitted elastic girdle used after midline laparotomy was found to be safe, as this did not affect lung function, coughing, intra-abdominal pressure, or wound healing. The immediate decline in lung function after surgery is restrictive and due to anesthesia and the surgical procedure. Pain was significantly decreased in the girdle group. The study is registered at ClinicalTrials.gov, number NCT01517217.

Joint effect of obesity and TNFA variability on asthma: two international cohort studies.

Obesity is a risk factor for asthma. Adipose tissue expresses pro-inflammatory molecules including tumour necrosis factor (TNF), and levels of TNF are also related to polymorphisms in the TNF-alpha (TNFA) gene. The current authors examined the joint effect of obesity and TNFA variability on asthma in adults by combining two population-based studies. The European Community Respiratory Health Survey and the Swiss Cohort Study on Air Pollution and Lung and Heart Disease in Adults used comparable protocols, questionnaires and measures of lung function and atopy. DNA samples from 9,167 participants were genotyped for TNFA -308 and lymphotoxin-alpha (LTA) +252 gene variants. Obesity and TNFA were associated with asthma when mutually adjusting for their independent effects (odds ratio (OR) for obesity 2.4, 95% confidence interval (CI) 1.7-3.2; OR for TNFA -308 polymorphism 1.3, 95% CI 1.1-1.6). The association of obesity with asthma was stronger for subjects carrying the G/A and A/A TNFA -308 genotypes compared with the more common G/G genotype, particularly among nonatopics (OR for G/A and A/A genotypes 6.1, 95% CI 2.5-14.4; OR for G/G genotype 1.7, 95% CI 0.8-3.3). The present findings provide, for the first time, evidence for a complex pattern of interaction between obesity, a pro-inflammatory genetic factor and asthma.

TNFA -308G>A in two international population-based cohorts and risk of asthma.

Genetic association studies have related the tumour necrosis factor-alpha gene (TNFA) guanine to adenine substitution of nucleotide -308 (-308G>A) polymorphism to increased risk of asthma, but results are inconsistent. The aim of the present study was to test whether two single-nucleotide polymorphisms, of TNFA and of the lymphotoxin-alpha gene (LTA), are associated with asthma, bronchial hyperresponsiveness and atopy in adults, by combining the results of two large population-based multicentric studies and conducting a meta-analysis of previously published studies. The European Community Respiratory Health Survey (ECRHS) and Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA) used comparable protocols, including questionnaires for respiratory symptoms and measures of lung function and atopy. DNA samples from 11,136 participants were genotyped at TNFA -308 and LTA 252. Logistic regression employing fixed and random effects models and nonparametric techniques were used. The prevalence of asthma was 6%. The TNFA -308G>A polymorphism was associated with increased asthma prevalence and with bronchial hyperresponsiveness. No consistent association was found for atopy. The LTA 252A>G polymorphism was not associated with any of the outcomes. A meta-analysis of 17 studies showed an increased asthma risk for the TNFA -308 adenine allele. The tumour necrosis factor-alpha gene nucleotide -308 polymorphism is associated with a moderately increased risk of asthma and bronchial hyperresponsiveness, but not with atopy. These results are supported by a meta-analysis of previously published studies.

Repair of psoralen and acetylaminofluorene DNA adducts by ABC excinuclease.

Escherichia coli UvrA, UvrB and UvrC proteins acting in concert remove the major ultraviolet light-induced photoproduct, the pyrimidine dimer, from DNA in the form of a 12 to 13-nucleotide long single-stranded fragment. In vivo data indicate that the UvrABC enzyme is also capable of removing other nucleotide diadducts as well as certain nucleotide monoadducts from DNA and initiating the repair process that leads to removal of interstrand crosslinks caused by some bifunctional chemical agents. We have determined the action mechanism of the enzyme on nucleotide monoadducts produced by 4'-hydroxymethyl-4,5',8-trimethylpsoralen and N-acetoxy-N-2-acetylaminofluorene. In both cases we find that the enzyme hydrolyzes the eighth phosphodiester bond 5' and the fifth phosphodiester bond 3' to the modified base. This cutting pattern is similar to that observed with diadduct substrate, the only difference being that while the enzyme incises the fourth or fifth phosphodiester bond 3' to the pyrimidine dimer it always hydrolyzes the fifth bond relative to monoadducts. Our results also suggest that ABC excinuclease cuts the same two phosphodiester bonds on both sides of a T whether that T has a psoralen monoadduct or is involved in psoralen-mediated interstrand crosslink.

Sleep-disordered breathing in women: occurrence and association with coronary artery disease.

PURPOSE: To examine the occurrence of sleep apnea and nocturnal hypoxemia in women with and without coronary artery disease (CAD) and to investigate the relationship between sleep-disordered breathing and coronary artery disease. PATIENTS AND METHODS: In a case-control study, 102 cases were randomly selected among women with angina pectoris and angiographically verified coronary disease. Fifty age-matched controls without known heart disease were selected from the population registry. Pulse oximetry, oronasal thermistors, body position indicator, and recording of body and respiratory movements were used to quantify oxygen desaturations (the number of desaturations > or = 4% per hour of sleep, oxygen desaturation index [ODI]) and apneas (the number of apneas or hypopneas per hour of sleep, apnea-hypopnea index [AHI]). RESULTS: Women with CAD had a high occurrence of disordered breathing measured as AHI > or = 5, 54% (n = 54), AHI > or = 10, 30% (n = 30) or ODI > or = 5, 34% (n = 35) while the same proportions in controls were 20% (n = 10, P < 0.0001), 10% (n = 5, P < 0.01) and 18% (n = 9, P < 0.05), respectively. In a multiple logistic regression model, sleep apnea (AHI > or = 5), hypertension, and smoking habits were independent predictors of CAD with odds ratios of 4.1 (95% confidence interval [CI] 1.7 to 9.7, P < 0.01), 3.4 (CI 1.3 to 8.9, P < 0.05) and 2.4 (CI 1.0 to 5.7, P < 0.05), respectively. CONCLUSION: Sleep apnea is common in women with CAD and remains as a significant predictor of coronary disease after adjustment for age, body mass index, hypertension, smoking habits, and diabetes.

Treatment success with a mandibular advancement device is related to supine-dependent sleep apnea.

STUDY OBJECTIVE: To evaluate the effect of a mandibular advancement device in patients with supine-dependent sleep apnea and patients with non-supine-dependent sleep apnea. DESIGN: Prospective study. SETTING: Department of Respiratory Medicine, University Hospital, Umeå, Sweden. PATIENTS: Twenty-six patients with obstructive sleep apnea. INTERVENTION: Individually fabricated and adjusted mandibular advancement devices. MEASUREMENTS: Overnight polysomnographic sleep recordings with and without the device. Supine-dependent sleep apnea was defined when the supine apnea-hypopnea index was > or = 10, together with a lateral apnea-hypopnea index of < 10. Non-supine-dependent sleep apnea was considered when the lateral apnea-hypopnea index was > or = 10. RESULTS: In 12 patients with supine-dependent sleep apnea, the device reduced the supine apnea-hypopnea index from a median of 41 (range, 16 to 70) to 5.9 (range, 0.0 to 15) (p < 0.01). In 14 patients with non-supine-dependent sleep apnea, the treatment reduced the supine apnea-hypopnea index from 44 (range, 1.8 to 73) to 21 (range, 6.3 to 60) (p < 0.05) and the lateral apnea-hypopnea index from 21 (range, 12 to 70) to 4.5 (range, 0.0 to 31) (p < 0.01). The odds ratio for a successful apnea reduction to an apnea-hypopnea index of < 10 in both the supine and the lateral positions was 30 for supine-dependent sleep apnea adjusted for age, obesity, mandibular advancement, and mandibular opening (p < 0.01). CONCLUSION: Successful apnea reduction with a mandibular advancement device is highly related to supine-dependent sleep apnea.

Effect of nasal-valve dilation on obstructive sleep apnea.

OBJECTIVE: Nasal-valve dilation reduces nasal resistance and increases air flow. It is possible that this mechanism prevents hypopharyngeal collapse and sleep apneas. We investigated the effect of a plastic device (Nozovent; Prevancure AB; Västra Frölunda, Sweden)-which dilates the nasal valve-on patients with obstructive sleep apnea (OSA). DESIGN: Prospective interventional study. SUBJECTS: Twenty-six consecutive patients with OSA were included (22 men; mean +/- SD age, 54.8+/-11.3 years; respiratory disturbance index [RDI], 34.4+/-18.5 events/h; body mass index, 31.6+/-5.7 kg/m(2)). INTERVENTION: The nasal dilator was inserted during sleep into the nares and fitted to exert a dilating force on the nasal valves by means of its elasticity. MEASUREMENTS: Polysomnographic studies were performed before and after 1 month of treatment. A responder is defined as one with a reduction in RDI to < 50% of the baseline value and RDI of < or =10 events/h during treatment. RESULTS: Five patients dropped out. As a result, only 21 patients were analyzed. Four patients responded, and 17 patients were nonresponders. In the whole population, neither the mean values for respiration during sleep nor sleep staging changed significantly with the device. CONCLUSIONS: The investigated nasal dilator had no effect on sleep-related breathing disorders in patients with moderate to severe OSA. The reduction in nasal resistance does not prevent hypopharyngeal obstruction.

Reversal of central sleep apnea with oxygen.

OBJECTIVE: To examine the effect of oxygen on apneas and sleep quality in patients with frequent central apneas during sleep. DESIGN/SUBJECTS: Prospective intervention study of 20 consecutive patients with predominant central apnea identified from 570 patients referred for suspected sleep apnea syndrome. Sixteen patients had congestive heart failure and seven of them had a previous stroke. Three of the remaining four patients without heart failure had experienced a previous stroke, and one was being treated with morphine. SETTING: The Department of Pulmonary Medicine at Umeå (Sweden) University Hospital. INTERVENTIONS: The patients were investigated for one night receiving nasal oxygen and one night without it. MEASUREMENTS: Overnight polysomnography with transcutaneous PCO2 and arterial blood gases. RESULTS: Central apneas occurred during Cheyne-Stokes respiration in 18 of 20 patients and two patients had idiopathic central apneas. Without oxygen, the median number of all central apneas and hypopneas was 33.5 (range, 8.0 to 52.0) per hour of sleep. These episodes decreased to 5.0 (range, 0.0 to 31.0)(p < 0.01) during oxygen therapy. In 17 of 20 patients, the frequency of central apneas was reduced by more than 50%. Central apneas were reduced by oxygen irrespective of the presence or absence of heart failure or Cheyne-Stokes respiration. The arousal frequency was reduced during oxygen treatment. Daytime sleepiness, difficulty falling asleep, snoring, and self-scored awakenings were reduced in seven patients who were given nocturnal oxygen at home. Obstructive and mixed apneas were unaffected by oxygen. CONCLUSIONS: Oxygen effectively reduces central sleep apnea in eucapnic patients.

Sleep-disordered breathing and myocardial ischemia in patients with coronary artery disease.

STUDY OBJECTIVES: To examine the occurrence of nocturnal myocardial ischemia and its relationship to sleep-disordered breathing (apneas and oxygen desaturations) in randomly selected men and women undergoing coronary angiography because of angina pectoris. DESIGN: An observational study using an overnight sleep study and Holter recording to examine disordered breathing (oxyhemoglobin desaturations > or = 4% and apnea-hypopneas), heart rates, and ST-segment depressions (> or = 1 mm, > or = 1 min). SETTING: University Hospital, Umeå, a teaching hospital in northern Sweden. PATIENTS: One hundred thirty-two men and 94 women referred for consideration of coronary intervention were randomly included, by lot. RESULTS: ST-segment depressions occurred in 59% (134 of 226) of the patients, and nocturnal ST-segment depressions occurred in 31% (69 of 226). A ST-segment depression occurred within 2 min after an apnea-hypopnea or desaturation in 12% (27 of 226) of patients. This temporal association was seen in 19% of nocturnal ST-segment depressions (71 of 366), more frequently in men (p < 0.01) and in more severely disordered breathing (p < 0.001). Most of these ST-segment depressions were preceded by a series of breathing events: three or more apnea-hypopneas or desaturations or both in 70% (50 of 71). CONCLUSION: Episodes of nocturnal myocardial ischemia are common in patients with angina pectoris. However, a temporal relationship between sleep-disordered breathing and myocardial ischemia is present only in a minority of the patients, but occurs more frequently in men and in more severely disordered breathing.

The effect of a mandibular advancement device on apneas and sleep in patients with obstructive sleep apnea.

OBJECTIVE: To evaluate the effects of a mandibular advancement device on apneas and sleep in mild, moderate, and severe obstructive sleep apnea. DESIGN: Prospective study. SUBJECTS: Forty-four of 47 patients included. INTERVENTION: Individually adjusted mandibular advancement devices. MEASUREMENTS: Polysomnographic sleep recordings for 1 night without the device and 1 night with it, with a median of 1 day and no changes in weight, medication, or sleep position between the recordings. RESULTS: The device reduced the median obstructive apnea-hypopnea index from 11 (range, 7 to 19) to 5 (range, 0 to 17) (p<0.001) in 21 patients with mild sleep apnea, from 27 (range, 20 to 38) to 7 (range, 1 to 19) (p<0.001) in 15 patients with moderate sleep apnea, and from 53 (range, 44 to 66) to 14 (range, 2 to 32) (p<0.05) in 8 patients with severe sleep apnea. The arousal index decreased and the sleep stage patterns improved in all severity groups. Twenty-eight of 44 patients were successfully treated with an obstructive apnea-hypopnea index of below 10 and a subjective reduction in snoring. Nine of 16 patients with treatment failure still reported a reduction in snoring. The success rate correlated inversely to the disease severity (r=-0.41; p<0.01). CONCLUSIONS: A mandibular advancement device reduces apneas and improves sleep quality in patients with obstructive sleep apnea, especially in those with mild and moderate disease. A follow-up sleep recording during treatment is necessary because of the risk of silent obstructive apneas without subjective snoring with the device.

Sleep-disordered breathing in men with coronary artery disease.

OBJECTIVE: To examine the occurrence of sleep apnea and nocturnal hypoxemia in men with symptomatic coronary artery disease (CAD) and to evaluate the relationship between disordered breathing and coronary artery disease. DESIGN: Case-control study. Cases were randomly selected from men undergoing coronary angiography because of angina pectoris. Controls were age matched and selected from the population registry. Pulse oximetry, oronasal thermistors, body position indicator, and recording of body and respiratory movements were used to quantify desaturations and apneas. SETTING: Norrland University Hospital, a referral center for northern Sweden. SUBJECTS: One hundred forty-two men with angina pectoris and angiographically verified CAD and 50 controls without known heart disease. MAIN OUTCOME MEASURES: The number of arterial oxygen desaturations of 4% or more per hour of sleep, oxygen desaturation index (ODI), and the number of apneas or hypopneas per hour of sleep, apnea-hypopnea index (AHI). RESULTS: Men with CAD had a high occurrence of sleep-disordered breathing measured as ODI of 5 or more, 39% (n=55), or AHI of 10 or more, 37% (n=50), while, the same proportions in controls were 22% (n=11, p<0.05) and 20% (n=10, p<0.05). Mean values of ODI in cases and controls were 6.4 and 2.7, respectively (p<0.001). Multiple logistic regression analysis identified ODI, AHI, body mass index, and hypertension as significant predictors of CAD (p<0.05). CONCLUSION: Sleep- disordered breathing is common in men with CAD. A significant association between sleep apnea with nocturnal hypoxemia and CAD remains after adjustment for age, hypertension, body mass index, diabetes, and smoking.

Mandibular advancement device in patients with obstructive sleep apnea : long-term effects on apnea and sleep.

STUDY OBJECTIVES: To evaluate the long-term effects on apneas and sleep and the tolerability of a mandibular advancement device in patients with obstructive sleep apnea. DESIGN: Prospective study. SETTING: Department of Respiratory Medicine, University Hospital, Umeå, Sweden. PATIENTS: Thirty-three consecutively treated patients. INTERVENTIONS: Individually adjusted mandibular advancement devices. MEASUREMENTS AND RESULTS: Polysomnographic sleep recordings on 1 night without the device and 1 night with the device were performed after 0.7 +/- 0.5 years (mean +/- SD) and after 5.2 +/- 0.4 years from the start of treatment. Nineteen of the 33 patients experienced a short-term satisfactory treatment result with an apnea-hypopnea index of < 10 events per hour and a satisfactory reduction in snoring. Fourteen patients were regarded as being insufficiently treated with the device. Seventeen of the short-term satisfactorily treated patients (90%) and 2 of the remaining patients continued treatment on a long-term basis. The apnea-hypopnea index was reduced by the device from 22 +/- 17 to 4.9 +/- 5.1 events per hour (p < 0.001) in these 19 long-term treatment patients, which did not differ from what was found at the short-term follow-up visits in these patients. Patients with their devices replaced or adjusted experienced a better long-term effect than patients still using their original devices (p < 0.05). CONCLUSIONS: The long-term effect and tolerability of a mandibular advancement device are good in patients who are recommended the treatment on the basis of a short-term sleep recording, provided that the device is continuously adjusted or replaced with a new one when needed. A short-term follow-up is valuable in the selection of patients who will benefit from long-term treatment with a mandibular advancement device.

Snoring, pregnancy-induced hypertension, and growth retardation of the fetus.

STUDY OBJECTIVE: Our purpose was to study the relationship between snoring and pregnancy-induced hypertension and growth retardation of the fetus. DESIGN: Retrospective, cross-sectional, consecutive case series. SETTING: The Department of Gynecology and Obstetrics, University Hospital, Umeâ, Sweden. PARTICIPANTS AND MEASUREMENTS: On the day of delivery, 502 women with singleton pregnancies completed a questionnaire about snoring, witnessed sleep apneas, and daytime fatigue. Data concerning medical complications were taken from the women's casebooks. RESULTS: During the last week of pregnancy, 23% of the women reported snoring every night. Only 4% reported snoring before becoming pregnant. Hypertension developed in 14% of snoring women, compared with 6% of nonsnorers (p < 0.01). Preeclampsia occurred in 10% of snorers, compared with 4% of nonsnorers (p < 0.05). An Apgar score < or = 7 was more common in infants born to habitual snorers. Growth retardation of the fetus, defined as small for gestational age at birth, had occurred in 7.1% of the infants of snoring mothers and 2.6% of the remaining infants (p < 0.05). Habitual snoring was independently predictive of hypertension (odds ratio [OR], 2.03; p < 0.05) and growth retardation (OR, 3.45; p < 0.01) in a logistic regression analysis controlling for weight, age, and smoking. CONCLUSIONS: Snoring is common in pregnancy and is a sign of pregnancy-induced hypertension. Snoring indicates a risk of growth retardation of the fetus.

Sleep apnea, delirium, depressed mood, cognition, and ADL ability after stroke.

OBJECTIVES: The incidence of sleep apnea and stroke increases with age. The aim of this study was to investigate the presence of sleep apnea after stroke and its relationship to delirium, depressed mood, cognitive functioning, ability to perform activities of daily living (ADLs), and psychiatric and behavior symptoms. DESIGN: Cross-sectional study. SETTING: Geriatric stroke rehabilitation unit. PARTICIPANTS: 133 patients (78 women and 55 men, mean age 77.1 +/- 7.7 years) consecutively admitted to a geriatric stroke rehabilitation unit. MEASUREMENTS: All patients underwent overnight respiratory sleep recordings at 23 +/- 7 days (range 11 to 41 days) after suffering a stroke. The patients were assessed using the Organic Brain Syndrome Scale, Montgomery-Asberg-Depression-Rating Scale, Mini-Mental State Examination (MMSE), and Barthel-ADL Index. Sleep apnea was defined as an apnea-hypopnea index (AHI) of 10 or more. RESULTS: The median of the AHI for the studied sample (N = 133) was 13 (range 0-79; interquartile range 6-28). Fifty-nine percent fulfilled the criteria for sleep apnea; 52% with first-ever stroke had sleep apnea. More patients with sleep apnea than without were delirious, depressed, or more ADL-dependent. Sleep apnea patients also had a higher frequency of ischemic heart disease and had more often suffered from an earlier cerebral infarction. Multivariate analysis showed that obesity, low ADL scores, ischemic heart disease, and depressed mood were independently associated with sleep apnea. Low ADL scores, apnea-related hypoxemia, body mass index < or = 27, and impaired vision were independently associated with delirium. The presence of sleep apnea was not associated with any specific type of stroke or location of the brain lesion. CONCLUSIONS: Sleep apnea is common in stroke patients and is associated with delirium, depressed mood, latency in reaction and in response to verbal stimuli, and impaired ADL ability. We suggest a trial investigating whether delirium, depressed mood, and ADL ability improve with nasal continuous positive airway pressure treatment of sleep apnea in stroke patients.

Hemodynamics, cerebral circulation, and oxygen saturation in Cheyne-Stokes respiration.

Because cardiovascular disorders and stroke may induce Cheyne-Stokes respiration, our purpose was to study the interaction among cerebral activity, cerebral circulation, blood pressure, and blood gases during Cheyne-Stokes respiration. Ten patients with heart failure or a previous stroke were investigated during Cheyne-Stokes respiration with recordings of daytime polysomnography, cerebral blood flow velocity, intra-arterial blood pressure, and intra-arterial oxygen saturation with and without oxygen administration. There were simultaneous changes in wakefulness, cerebral blood flow velocity, and respiration with accompanying changes in blood pressure and heart rate approximately 10 s later. Cerebral blood flow velocity, blood pressure, and heart rate had a minimum occurrence in apnea and a maximum occurrence during hyperpnea. The apnea-induced oxygen desaturations were diminished during oxygen administration, but the hemodynamic alterations persisted. Oxygen desaturations were more severe and occurred earlier according to intra-arterial measurements than with finger oximetry. It is not possible to explain Cheyne-Stokes respiration by alterations in blood gases and circulatory time alone. Cheyne-Stokes respiration may be characterized as a state of phase-linked cyclic changes in cerebral, respiratory, and cardiovascular functions probably generated by variations in central nervous activity.

The accuracy of subjective sleep time in sleep apnoea recordings.

Total sleep time is important in investigations of obstructive sleep apnoea, since the diagnosis is usually based on the average number of apnoeas per hour of sleep. Sleep estimates instead of exact EEG-recorded total sleep time is often used in the clinical setting. However, an overestimated sleep time would underestimate the degree of the disease and vice versa. The purpose of this study was to investigate the accuracy of subjective sleep time and time-in-bed as sleep estimates. One hundred patients undergoing diagnostic polysomnography for suspected obstructive sleep apnoea were asked to estimate their sleep time in a questionnaire. Seventy-five patients were diagnosed as suffering from obstructive sleep apnoea syndrome. The mean difference between self-scored and EEG-recorded total sleep time was 4 +/- 74 min. However, 30% scored with a difference greater than 1 h. The intra-class correlation coefficient was fair (0.58, CI: 0.43-0.70). Fifty-three patients overestimated their sleep time and 47 patients underestimated it. All but four patients underestimated their number of awakenings (P<0.001). The mean difference between time-in-bed and EEG-recorded total sleep time was 110 +/- 63 min. This difference was significantly larger than the difference between subjective sleep time and EEG-recorded total sleep time (P<0.001). The intra-class correlation coefficient was poor (0.38, CI: 0.20-0.54). Mean AHI was 27 +/- 27 using subjective sleep time and did not change significantly compared with the mean AHI of 25 +/- 21 based on EEG-recorded total sleep time. Mean AHI decreased significantly to 20 +/- 17 (P<0.001) when time-in-bed was used. In conclusion, 'time-in-bed' time is a poor predictor of total sleep time and should not be used when calculating the apnoea-hypopnoea index. Subjective sleep time is better as an approximation, but the individual differences are large.

Symptoms related to obstructive sleep apnoea are common in subjects with asthma, chronic bronchitis and rhinitis in a general population.

The purpose of this study was to examine the prevalence of self-reported snoring, apnoeas and daytime sleepiness in relation to chronic bronchitis, recurrent wheeze, physician-diagnosed asthma and rhinitis. This was a questionnaire study in a representative sample of a general population. The study was a part of the Obstructive Lung Disease in Northern Sweden Studies (OLIN). A total of 5424 subjects aged 20-69 years, born on the 15th day of each month, participated in the study. Eligible answers were obtained from 4648 subjects (85.7%). Having snoring as a problem was reported by 10.7%. Among subjects with chronic bronchitis it was reported by 25.9%, with recurrent wheeze by 21.3%, with physician-diagnosed asthma by 17.9%, and with rhinitis by 14.7%. Relatives' concerns of witnessed apnoea was reported by 6.8% of all subjects, while among subjects with chronic bronchitis it was reported by 18.1%, with recurrent wheeze by 17.1%, with physician-diagnosed asthma by 14.3%, and with rhinitis by 9.1%. After correction for age, gender and smoking habits, chronic bronchitis, rhinitis, asthma, and current smoking were significantly related, with snoring as a problem and with relatives' concern of witnessed apnoeas. Symptoms of daytime sleepiness were significantly related with concern of witnessed apnoeas, chronic bronchitis, snoring as a problem, recurrent wheeze and age 50-59 years. In conclusion, respiratory symptoms and conditions affecting mainly the lower respiratory tract, such as chronic bronchitis and asthma, were related with symptoms common in obstructive sleep apnoea.