non-OSA Patients Research Articles

The Effect of Surgical Treatment of Obstructive Sleep Apnea Syndrome on the Plasma TNF-.ALPHA. Levels

Obstructive sleep apnea syndrome (OSAS) is defined as intermittent complete or partial upper airway obstruction during sleep, causing mental and physical effects. Both the local and systemic inflammation observed in OSAS induce certain potent pro-inflammatory mediators, which may contribute to the development of cardiovascular consequences. The present study was designed to evaluate the plasma levels of TNF-alpha, which is one of the known pro-inflammatory cytokines, in patients with OSAS and to assess the effect of surgical treatment on the levels of TNF-alpha levels. Twenty seven patients diagnosed to have OSAS, 7 non-apneic patients with chronic tonsillitis (non-OSAS patients), and 4 healthy subjects were enrolled in this study. Blood samples were collected one week preoperatively and postoperatively, and the plasma TNF-alpha levels were measured using high-sensitivity ELISA. The plasma TNF-alpha levels in patients with OSAS were significantly elevated in comparison to normal healthy subjects. In contrast, there was no difference between the patients with non-OSAS and healthy subjects. Moreover, the surgical treatment to enlarge the upper airway in patients with OSAS significantly decreased the levels of TNF-alpha levels. Surgical treatment of patients with OSAS reduces the plasma TNF-alpha levels, thereby ameliorating the systemic inflammation and preventing the development of cardiovascular consequences.

The diagnosis of obstructive sleep apnea as a risk factor for unanticipated admissions in outpatient surgery.

The goal of this study was to determine whether the preoperative diagnosis of obstructive sleep apnea (OSA) is an independent risk factor for perioperative complications in patients undergoing nonotorhinolaryngologic outpatient surgical procedures. We used existing databases to identify 234 patients with polysomnography-confirmed OSA who had outpatient surgical procedures in the years 1997 through 2000. Control patients were matched for type of anesthesia, age, sex, body mass index, surgical procedure, and surgical date. Their perioperative medical records were reviewed. There was no significant difference in the intraoperative management of OSA and control patients, except that the laryngeal mask airway was less likely to be used in OSA patients. There was no significant difference in the rate of unplanned hospital admissions (23.9% versus 18.8%; odds ratio, 1.4; 95% confidence interval, 0.8-2.5) or other adverse events (2.1% versus 1.3%; odds ratio, 1.7; 95% confidence interval, 0.4-7.0) between OSA and non-OSA patients. Further, when admission did occur, it was generally unrelated to cardiac or respiratory events. In this retrospective analysis, the preoperative diagnosis of OSA was not a risk factor for either unanticipated hospital admission or for other adverse events among patients undergoing outpatient surgical procedures in a tertiary referral center. In patients scheduled for outpatient surgery in a large academic practice, the diagnosis of obstructive sleep apnea confirmed by polysomnography was not an independent risk factor for unanticipated hospital admission or for other adverse perioperative events.

Acoustic rhinometry findings in patients with mild sleep apnea.

Nasal obstruction may contribute to the development of obstructive sleep apnea (OSA). Acoustic rhinometry (AR) measures nasal patency and congestion, which are useful parameters in objectively evaluating nasal obstruction. The nasal obstruction produced by allergic rhinitis may contribute to the development of OSA and can be easily assessed with AR. This study was undertaken to assess the degree of nasal obstruction seen in allergic patients with and without OSA. This study was a retrospective data analysis from a tertiary referral center. The AR data from 10 patients with and 40 patients without mild OSA were compared. The mean congestion factors at the first cross-sectional area (CSA1) on the AR graph were found to be significantly higher in the OSA group than in the non-OSA group (P = 0.03). The classification of change in congestion factors demonstrated significant differences at CSA1, CSA2, and CSA3 and in volume (t distributions <0.001, 0.0312, <0.001, and <0.001, respectively). The non-OSA patients noted a significant subjective improvement in nasal congestion after topical nasal decongestion, whereas the OSA patients did not (P <or= 0.0001 and 0.064, respectively). Although the role of nasal obstruction in OSA is controversial, our study lends evidence to the thought that the nasal obstruction associated with allergic rhinitis is associated with the presence of mild OSA. Whether allergic rhinitis is a direct cause of OSA is debatable, but we have shown that greater nasal congestion is related to the presence of OSA in a population of patients with allergic rhinitis.

Cephalometric Analysis in Patients with Obstructive Sleep Apnea Syndrome

We assessed the surgical indication in obstructive sleep apnea syndrome (OSAS) by comparing cephalometry between a responder group of uvulopalatopharyngoplasty (UPPP) and a nonresponder group. Cephalometric studies were conducted on 43 patients--42 men and one women--who required UPPP and underwent both pre- and postoperative polysomnography, and on 50 non-OSAS patients who formed the control group. Angles and distances were measured based on the Downs-Northwestern method as detailed in the reference cited. The comparison between the OSAS and control groups indicated anterior displacement of the maxilla, and anteroposterior discrepancies of the maxilla and the mandible in OSAS. Significant differences were seen in distance measurements for all values other than the distance from the sella to the nasion. We then compared the 3 groups--responders, nonresponders, and controls. From differences in the Y-axis angle, the Gonial angle, the ANB angle, the distance from the gonion to the menton, and the maximum thickness of the soft palate between responder and control groups, we concluded that the efficacy of UPPP is higher in OSAS patients who have several factors such as micrognathia, anteroposterior discrepancy in the maxillary and mandibular bases, and thick soft palate. We concluded that routinely conducting that cephalometric analysis would be useful for deciding on adopting UPPP.

Screening of obstructive sleep apnoea: heart rate spectral analysis of nocturnal pulse oximetric recording

Using heart rate spectral analysis of nocturnal pulse oximetry, we prospectively evaluated the utility of this methodology in patients clinically suspected of having obstructive sleep apnoea (OSA). A hundred and ninety-seven outpatients referred with symptoms compatible with the diagnosis of OSA were studied. All participants had nocturnal pulse oximetry performed simultaneously with conventional polysomnography. Power density of heart rate obtained by nocturnal pulse oximetry was analysed using fast Fourier transformation of a Hamming-windowed signal. Recording test results were classified as abnormal (suspicion of OSA) in the presence of a peak in the periodogram between period boundaries 30–70 sec. A normal test result was defined as the absence of the 30–70 sec peak in the periodogram. The total area of the periodogram (STOT), the area enclosed in the periodogram between the period boundaries 30–70 sec (S30–70), the area enclosed in the period boundaries 30–70 sec with respect to the total area of the periodogram (S) and the peak amplitude 30–70 sec (PA) were measured. The presence of a peak in the periodogram has a sensitivity of 81·3%, a specificity of 91·5%, a positive predictive value of 89·1% and a negative predictive value of 85·1% for OSA diagnosis. The OSA patients were found to have higher values of STOT, S30–70, S and PA than the non-OSA patients. Receiver operating characteristics (ROC) curve was constructed at different thresholds of STOT, S30–70S and PA. For a PA threshold of 10(%)2, heart rate spectral analysis sensitivity for OSA was 58% and specificity was 92%. Furthermore, the positive and negative predictive values for diagnosis of OSA were 87 and 72% respectively. Apnoea-hypopnea index (AHI) correlated significantly with STOT(r=0·44;P<0·001), S30–70(r=0·59;P<0· 001), S (r=0·58;P<0·001) and PA (r=0·58;P<0·001). According to our results, heart rate spectral analysis obtained by nocturnal pulse oximetry and identification of peak in the periodogram between period boundaries 30–70 sec could be useful as a diagnostic technique for OSA patients.

Does obstructive sleep apnea confound sleep architecture findings in subjects with depressive symptoms?

Background: Compared with normal subjects, depressed patients have shorter rapid eye movement sleep latency (REML), increased REM and decreased slow wave sleep as a percentage of total sleep time (REM%, SWS%), and longer sleep latency (SL). Obstructive sleep apnea (OSA) patients experience longer REML, decreased REM% and SWS%, and shorter SL. We examined the interplay of depressive symptoms, OSA, and sleep architecture. Methods: Subjects ( n = 106) were studied with polysomnography. OSA was defined as a Respiratory Disturbance Index ≥15. Subjects were divided into Hi/Lo groups using a Center for Epidemiological Studies—Depression (CES-D) score of 16. Results: OSA patients had shorter SL than non-OSA patients (14.5 vs. 26.8 min, p < .001); Hi CES-D subjects showed a trend toward longer SL than Lo CES-D subjects (23.7 vs. 17.5 min, p = .079). Significant OSA × CES-D interactions emerged, however, for REM% ( p = .040) and SL ( p = .002): OSA/Hi CES-D subjects had higher REM% than OSA/Lo CES-D subjects (19.3% vs. 14.3%, p = .021); non–OSA/Hi CES-D subjects had SL (35.3 min) 2–3 times as long as other subjects ( p = .002–.012). Conclusions: Because of the high prevalence of OSA and depression, findings suggest that OSA must be considered in studies of mood and sleep architecture. Conversely, depressive symptoms must be considered in studies of OSA and sleep architecture.

Value of Clinical, Functional, and Oximetric Data for the Prediction of Obstructive Sleep Apnea in Obese Patients

To evaluate the diagnostic value of clinical features, pulmonary function testing, blood gas tensions, and oximetric data for case finding of obstructive sleep apnea (OSA) before polysomnography (PSG) in a series of consecutive overweight patients. We studied a population of 102 consecutive patients referred by an obesity clinic for suspected OSA, in whom body mass index was > or = 25 kg/m(2). The following tests were performed: clinical score (CS), pulmonary function tests (PFTs), measurement of arterial blood gas tensions, nocturnal oximetry, and full-night PSG. Six of 34 women and 34 of 68 men had OSA, defined by an apnea-hypopnea index > or = 15. CS and the cumulative time spent below 80% arterial oxygen saturation (SaO(2)) were higher, and PaO(2), minimal SaO(2), and mean nocturnal SaO(2) (mSaO(2)) were lower in OSA patients than in non-OSA patients. Logistic regression showed that sex, CS, and the ratio of FEV(1) over forced expiratory volume in 0.5 s (an index of upper airway obstruction on flow-volume curves) and mSaO(2), expressed as categorical variables, were independent predictors of OSA. None of these individual variables had a satisfactory diagnostic value for the diagnosis of OSA. A logistic regression model including sex and all continuous variables would have allowed us to predict the presence or absence of OSA confidently in 72.5% of the population, in whom the positive predictive value of the model was 94% and the negative predictive value was 90%. In obese patients referred to a respiratory sleep laboratory and evaluated by CS, PFTs, arterial blood gases, and oximetry, no individual sign or symptom may accurately predict the presence or absence of OSA. Provided that it is validated in prospective studies, a logistic regression model using these variables may be useful for the prediction of OSA.

Sleep Apnea in Moderate-Severe Obese Patients.

Obesity induces multiple physiologic changes at the respiratory and circulatory systems level. A study was developed to identify symptoms and signs able to discriminate subjects at high risk of obstructive sleep apnea (OSA) and to evaluate the presence of OSA in a population of obese patients referred to the Clinical Nutrition Service of the Luigi Sacco Hospital for weight loss therapy. Twenty-seven obese patients (14 males, 13 females) without neurologic, cardiac, and lung diseases were measured for height, weight, neck, waist, and hip circumference; a sample of venous blood was taken for hematological data; and were given a pulmonary function test, hemogasanalysis, and full-night polysomnography. Statistical analysis were performed using paired and unpaired StudentOs t test, PearsonOs chi square, and Spearmann Rank correlation; the significance level was set at p<0.05. The results showed hemotological values in the normal range and pulmonary function findings were not different from predicted, but expiratory reserve volume (ERV), as expected in obese subjects, was significantly reduced (p<0.001). Waist, hip, and neck circumference, and waist/hip ratio were 114 +/-14, 118 +/-12, 44 +/-4, and 0.96 +/-0.4 cm respectively. An apnea-hypopnea index (AHI) cutoff value of <15 was used to classify the patients as suffering from OSA: 15 patients (12 males, 3 females, age in years 55 +/-12, body mass index (BMI) kg/m(2) 37 +/-6, AHI 30 +/-12) were OSA and 12 patients were non OSA (2 males, 10 females, age in years 49 +/-20, BMI kg/m(2) 35 +/-2, AHI 3 +/-2). PaO2 and pH were lower and PaCO2 higher in OSA (p<0.05, p<0.01, p<0.05, respectively). Red blood cells (RBC), Hb, and neck circumference were increased in OSA (p<0.05). In OSA patients, S3%, S4% of total sleep time, SaO2% mean of nadir were reduced (p<0.001), and DEF increased (p<0.0001). In obese patients, AHI was correlated with neck circumference (r = 0.74, p<0.0001) and waist/hip ratio (r = 0.48. p<0.01). DEF was correlated with RBC, Hb, Htc% (r = 0.82, 0.71, 0.66, p<0.001). SaO2;% mean of nadir was significantly related to RBC, Hb, and Htc% (r = 0.44, 0.40, p<0.05, respectively). Our data showed a prevalence of OSA in 55% of the obese patients. A significant correlation exists between RBC, Hb, Htc%, with desaturation events frequency (DEF) and SaO2% of nadir indicating that transient, episodic desaturation during sleep is linked to a moderate increase of RBC and Hb found in obese patients with OSA, in contrast to obese, nonOSA patients. The most important result of the present study was the determination that classical symptoms and signs of OSA, such as male gender, neck circumference, waist/hip ratio, RBC, and Hb at the upper limit of normal, are simple inexpensive screening tools, and useful predictors of sleep-disordered breathing and discriminate the individuals with higher risk of OSA.

Obstructive Sleep Apnea and Acute Myocardial Infarction: Clinical Implications of the Association

It is not known whether patients with acute myocardial infarction (MI) with coexistent obstructive sleep apnea (OSA) have a poor clinical course during the acute phase of MI. Therefore, we investigated the impact of OSA on in-hospital morbidity and mortality during an acute MI. Patients admitted to the intensive cardiac unit (ICU) with acute MI underwent Holter monitoring and night pulse oximetry (SpO2). During the first complete day at the ICU, both recordings (ECG and SpO2) were matched in time to determine association between cardiac arrhythmias and hypoxemia episodes. We identified and compared 55 heavy snorers with daytime sleepiness who showed more than 10 episodes of desaturation per hour on pulse oximetry (OSA group), and 196 nonOSA patients. There was an increase in the incidence of premature ventricular contraction (PVC, p < 0.05) and couplets PVC (p < 0.05) in OSA patients; the proportion of those arrhythmias increased in parallel with desaturation episodes in the OSA group. There were no differences between OSA and nonOSA groups for major MI complications (38.2% vs 34.2%, p > 0.05), ICU/hospital stay (3.6 +/- 1.2 vs 2.7 +/- 0.9 days, p > 0.05), or mortality within 30 days (14.5% vs 12.2%, p > 0.05). In conclusion, despite the greater incidence of some types of cardiac arrhythmias during an acute MI in OSA, these patients have the same clinical course in hospital and mortality rate as nonOSA patients.

Visceral fat accumulation as an important risk factor for obstructive sleep apnoea syndrome in obese subjects.

It is well known that obstructive sleep apnoea-(OSA) is frequently associated with obesity. In the current study, we investigated the correlation between abdominal visceral fat accumulation and the presence of OSA in obese subjects. A consecutive series of 37 patients (17 men and 20 women) with primary obesity who were admitted to the Second Department of Internal Medicine. Osaka University Hospital, were investigated Patients with OSA were designated as those whose apnoea index (number of apnoea h-1 of sleep) was more than 5. The distribution of body fat was determined using computed tomographic sections. The upper airway dimensions were evaluated with indices obtained by cephalometry in both inspiratory and expiratory phases. Visceral adipose tissue (AT) area which was measured at the level of the umbilicus, and its ratio to total AT area were both significantly greater in OSA patients as compared with those in non-OSA patients. All subjects whose visceral AT area measured more than 220 cm2 manifested OSA. These two parameters also closely correlated with an increase in apnoea index. A multiple linear regression analysis revealed that the visceral AT area significantly correlated to apnoea index when age, AT mass and lean body mass were taken into account. The fluctuations of the upper airway were significantly greater in the large visceral fat group than in the small visceral fat group. These results suggest that visceral fat accumulation is an important risk indicator for OSA in obese subjects.

Nasal continuous positive airway pressure. A new treatment for nocturnal gastroesophageal reflux?

Nasal continuous positive airway pressure (CPAP) reduces nocturnal gastroesophageal reflux (GER) in obstructive sleep apnea syndrome (OSAS) patients. The primary objectives of our investigation were to determine if CPAP could reduce reflux in non-OSAS patients and, if so, by what mechanism. Esophageal pH was monitored for 48 h in six nocturnal reflux patients. During the first 24 h, basal reflux data were collected; the second night, nasal CPAP was administered (pressure = 8 cm H2O). Esophageal manometry was obtained in six healthy adult volunteers both on and off nasal CPAP (pressure = 8 cm H2O) to ascertain CPAP's effects on esophageal pressure and peristalsis. The six reflux patients experienced less nocturnal GER while on CPAP. The mean percent time esophageal pH < 4 was reduced from 27.7 +/- 10.0 to 5.8 +/- 2.6 (p < 0.004); the mean reflux duration dropped from 2.1 +/- 0.6 to 0.9 +/- 0.5 min (p < 0.03); and the mean duration of longest reflux improved from 84.3 +/- 32.6 to 13.8 +/- 6.9 min (p < 0.01). The CPAP raised the mean resting midesophageal pressure by 4.4 cm H2O (p < 0.01) and the mean resting lower esophageal pressure (LES) by 13.2 cm H2O (p < 0.02) in the healthy volunteers. Nasal CPAP effectively reduced nocturnal GER in six patients with nocturnal reflux. The antireflux activity of CPAP is likely due to passive elevation of intraesophageal pressure and possibly to reflex LES constriction.

Cerebral hemodynamics in patients with hepatic coma: Examination of cerebrovascular response to CO 2: Sari A, Ogasahara H, Yamada K, et al. Jpn J Acute Med 1988;12:1665–1669

Although obstructive sleep apnea (OSA) is common and pneumonia is a frequent cause of acute respiratory failure requiring admission to the intensive care unit, little is known about the effect of OSA on this patient population. This study examined outcomes associated with OSA in patients with pneumonia requiring invasive mechanical ventilation.The Nationwide Inpatient Sample was investigated for discharges with a primary diagnosis of pneumonia requiring invasive mechanical ventilation between 2009 and 2011. Persons aged 18 to 75 years with OSA were compared with patients without OSA. Outcomes included in-hospital mortality and nonroutine discharges.Among 74 032 hospitalizations, 13.8% (10 227) were obese, and 10.3% (7610) had OSA. Obstructive sleep apnea patients had decreased in-hospital mortality (17.0% vs 25.8%; P < .01) and nonroutine discharge (74.4% vs 79.4%; P < .01) when compared with non-OSA patients. In adjusted logistic models, OSA was associated with a 27% decreased risk of in-hospital mortality (odds ratio, 0.73; 95% confidence interval, 0.68-0.79; P < .01) and a 21% decreased risk of nonroutine discharge (odds ratio, 0.79; 95% confidence interval, 0.74-0.84; P < .01).In mechanically ventilated patients with pneumonia, OSA was associated decreased in-hospital mortality and nonroutine discharge. It is possible that differences in treatment pattern may partially explain improved survival.

Cognitive dysfunction in type 2 diabetes patients accompanied with obstructive sleep apnea syndrome.

Objective: To investigate cognitive dysfunction of type 2 diabetes patients accompanied with obstructive sleep apnea syndrome (OSAS), and to analyze its relevant characteristics. Methods: Total 115 type 2 diabetes patients were divided into OSAS group (O group, n=83) and non-OSAS group (N group, n=32); Physical examination patients (C1 group, n=64) and OSAS patients without diabetes (C2 group, n=47) served as the control group. Apnea-hypopnea index (AHI), nocturnal lowest saturation of pulse oxygen (LSPO2) and simple mental state examination scale (MMSE) were evaluated. Results: Among diabetes patients, patients with OSAS have lower glycated hemoglobin, platelet count, thrombocytocrit, MMSE score and lowest mean arterial oxygen than non-OSAS patients; cognitive dysfunction state and glycemic control of patients are related to their diabetic duration, and then along with increase of diabetic duration, glycemic control becomes poor, so that cognitive dysfunction becomes more and more obvious. Conclusion: Along with increased diabetic duration in type 2 diabetes accompanied with OSAS, glycemic control becomes poor, so that cognitive dysfunction more easily occurs. Meanwhile, coagulation function of blood system in OSAS patients with diabetes is impacted to some extent.