Polysomnography

About: Polysomnography is a research topic. Over the lifetime, 19527 publications have been published within this topic receiving 858718 citations. The topic is also known as: PSG & polysomnogram.

Prevalence of sleep apnea in morbidly obese patients who presented for weight loss surgery evaluation: more evidence for routine screening for obstructive sleep apnea before weight loss surgery.

Abstract: The incidence of obstructive sleep apnea has been underestimated in morbidly obese patients who present for evaluation for weight loss surgery. This retrospective study shows that the incidence of obstructive sleep apnea in this patient population is greater than 70 per cent and increases in incidence as the body mass index increases. Obstructive sleep apnea (OSA) is a common comorbidity in obese patients who present for evaluation for gastric bypass surgery. The incidence of sleep apnea in obese patients has been reported to be as high as 40 per cent. A retrospective review of our prospectively collected database was performed. All patients being evaluated for weight loss surgery for obesity were screened preoperatively for OSA using a sleep study. The overall incidence of sleep apnea in our patients was 78 per cent (227 of 290). All 227 were diagnosed by formal sleep study. There were 63 (22%) males and 227 (78%) females. The mean age was 43 years (range, 17-75 years). The mean body mass index (BMI) was 52 kg/m2 (range, 31-94 kg/m2). The prevalence of OSA in the severely obese group (BMI 35-39.9 kg/m2) was 71 per cent. For the morbidly obese group (BMI 40-40.9 kg/m2), the prevalence was 74 per cent and for the superobese group (BMI 50-59.9 kg/m2) 77 per cent. Those with a BMI 60 kg/m2 or greater, the prevalence of OSA rose to 95 per cent. The incidence of sleep apnea in patients presenting for weight loss surgery was greater than 70 per cent in our study. Patients presenting for weight loss surgery should undergo a formal sleep study to diagnose OSA before bariatric surgery.

Relationship of sleep apnea to functional capacity and length of hospitalization following stroke.

Abstract: STUDY OBJECTIVES Recent evidence indicates that sleep apnea is common in patients with stroke. We hypothesized that the presence of sleep apnea among stroke patients would be associated with a greater degree of functional disability and longer hospitalization following stroke. DESIGN Prospective study. SETTING AND PATIENTS Sixty-one stroke patients admitted to a stroke rehabilitation unit. INTERVENTIONS N/A. MEASUREMENTS AND RESULTS Sleep studies were performed on all patients, and sleep apnea was defined as an apnea-hypopnea index of 10 or more per hour of sleep. Patients underwent functional assessments, including the Functional Independence Measure. Sleep apnea was found in 72% of patients; 60% had predominantly obstructive sleep apnea, while 12% had predominantly central sleep apnea. Although the severity of stroke was similar in the 2 groups, compared to patients without sleep apnea, those with sleep apnea had lower functional capacity [Functional Independence Measure score (mean +/- SEM) 80.2 +/- 3.6 versus 94.7 +/- 4.3, p < 0.05 at admission, and 101.5 +/- 2.8 versus 112.9 +/- 2.7, p < 0.05 at discharge] and spent significantly more days in rehabilitation (45.5 +/- 2.3 versus 32.1 +/- 2.7 days, p < 0.005). In addition, multiple regression analysis showed that obstructive sleep apnea was significantly and independently related to functional impairment and length of hospitalization. CONCLUSIONS Sleep apnea is very common among stroke patients undergoing rehabilitation, and its presence is associated with worse functional impairment and a longer period of hospitalization and rehabilitation. These data suggest that sleep apnea may be contributing to functional impairment and prolonged hospitalization following stroke.

The electroencephalographic fingerprint of sleep is genetically determined: a twin study

Abstract: Humans have an individual profile of the electroencephalographic power spectra at the 8 to 16 Hz frequency during non-rapid eye movement sleep that is stable over time and resistant to experimental perturbations. We tested the hypothesis that this electroencephalographic "fingerprint" is genetically determined, by recording 40 monozygotic and dizygotic twins during baseline and recovery sleep after prolonged wakefulness. We show a largely greater similarity within monozygotic than dizygotic pairs, resulting in a heritability estimate of 96%, not influenced by sleep need and intensity. If replicated, these results will establish the electroencephalographic profile during sleep as one of the most heritable traits of humans.

Pharyngeal shape and dimensions in healthy subjects, snorers, and patients with obstructive sleep apnoea.

Abstract: To characterise the relation between pharyngeal anatomy and sleep related disordered breathing, 17 men with complaints of snoring were studied by all night polysomnography. Ten of them had obstructive sleep apnoea (mean (SD) apnoea-hypopnoea index 56.3 (41.7), age 52 (10) years, body mass index 31.4 (5.3) kg/m2); whereas seven were simple snorers (apnoea-hypopnoea index 6.7 (4.6), age 40 (17) years, body mass index 25.9 (4.3) kg/m2). The pharynx was studied by magnetic resonance imaging in all patients and in a group of eight healthy subjects (age 27 (6) years, body mass index 21.8 (2.2) kg/m2, both significantly lower than in the patients; p less than 0.05). On the midsagittal section and six transverse sections equally spaced between the nasopharynx and the hypopharynx several anatomical measurements were performed. Results showed that there was no difference between groups in most magnetic resonance imaging measurements, but that on transverse sections the pharyngeal cross section had an elliptic shape with the long axis oriented in the coronal plane in normal subjects, whereas in apnoeic and snoring patients the pharynx was circular or had an elliptic shape but with the long axis oriented in the sagittal plane. It is suggested that the change in pharyngeal cross sectional shape, secondary to a reduction in pharyngeal transverse diameter, may be related to the risk of developing sleep related disordered breathing.

Effect of continuous positive airway pressure on ventricular ectopy in heart failure patients with obstructive sleep apnoea

Abstract: Background: Obstructive sleep apnoea (OSA) elicits a number of cardiovascular perturbations that could lead acutely or chronically to increased ventricular ectopy in patients with heart failure (HF). We tested the hypothesis that treatment of OSA with continuous positive airway pressure (CPAP) in patients with HF would reduce the frequency of ventricular premature beats (VPBs) during sleep in association with reduced sympathetic nervous system activity. Methods: Following optimisation of medical treatment, 18 HF patients with OSA and >10 VPBs per hour of sleep were randomised to a control group (n = 8) or a treatment group who received CPAP (n = 10). The frequency of VPBs and urinary norepinephrine (noradrenaline) concentrations during total sleep time were determined at baseline and after 1 month. Results: Control patients did not experience any significant changes in apnoea-hypopnoea index (AHI), mean nocturnal O2 saturation, or the frequency of VPBs. In contrast, there was a significant reduction in AHI (p<0.001), an increase in minimum O2 saturation (p = 0.05), a reduction in urinary norepinephrine concentrations (p = 0.009), and a 58% reduction in the frequency of VPBs during total sleep (from mean (SE) 170 (65) to 70 (28) per hour, p = 0.011) after 1 month of CPAP treatment. Conclusions: In patients with HF, treatment of co-existing OSA by CPAP reduces the frequency of VPBs during sleep. These data suggest that reductions in VPBs and other ventricular arrhythmias through treatment of OSA might improve the prognosis in patients with HF.