The Evaluation and Management of Sleep Disordered Breathing During Perioperative Period

Obstructive sleep apnea (OSA) is a syndrome defined frequently by decrease in arterial oxygen saturation, repeated upper airway obstruction episodes, increases in sympathetic output and tone, and repetitive arousals during sleep. OSA is the most common form of sleep-disordered breathing. In the United States, it has been estimated that 4% of middle aged males and 2% of middle aged females have OSA. Nevertheless the majority of patients who affect from OSA are undiagnosed and untreated. All these evidences imply that a prominent portion of OSA patients who undergo surgery will not be diagnosed and that the physicians must screen patients suspected of having sleep-disordered breathing to customize the anesthetic care and start necessary evaluations and therapy

Effects of Three Month Nasal Continuous Positive Airway Pressure Treatment on Electrocardiographic, Echocardiographic and Overnight Polysomnographic Parameters in Newly Diagnosed Moderate/Severe Obstructive Sleep Apnea Patients

The objective of the study was to determine the effects of nasal continuous positive airway pressure (nCPAP) therapy on left ventricular (LV) function and electrocardiographic parameters in newly diagnosed moderate/severe obstructive sleep apnea (USA) patients without cardiovascular comorbidities and medical treatments. We examined 44 patients who underwent overnight polysomnography together with 24-hour Ho lter electrocardiography, cardiopulmonary exercise testing including heart rate recovery at 1 minute (HRR-1), echocardiography, surface electrocardiography, and those who were diagnosed with moderate/severe USA apnea-hypopnea index >= 15. After 3 months of nCPAP treatment, the above-mentioned examinations were repeated. Forty-four patients completed the treatment period. Twelve weeks on effective nCPAP induced a significant increase in the mitral E/A ratio (P = 0.001), as well as reductions in isovolumic relaxation time (P = 0.001) and mitral deceleration time (DT) (P = 0.002). There were no significant differences in LV ejection fraction, LV mass index, and pulsed wave Doppler parameters. Mean heart rate was 79.2 +/- 12.5 pulses/minute, maximum P-wave duration 117.5 +/- 8.6 msec, P-wave dispersion (PWd) 54.6 +/- 10.2 msec, corrected QT interval (QTc) 436.5 +/- 40.5 msec, and QT dispersion (QTd) 46.3 +/- 7.1 msec, which significantly decreased to 70.4 +/- 9.6 pulses/minute (P <0.001), 111.5 +/- 8.7 msec (P <0.001), 51.6 +/- 8.9 msec (P <0.001), 418.4 +/- 31.2 msec (P <0.001), and 33.8 +/- 3.4 msec (P < 0.001), respectively. Exercise capacity at baseline determined as 10.5 +/- 2.2 metabolic equivalents (METS) and HRR-1 (20.6 +/- 11.7 bpm) significantly increased (12.1 +/- 1.5 METS and 27.4 +/- 8.6 bpm). There was no significant difference in aortic root parameters. Three-month nCPAP therapy significantly increased LV shortening fraction, with no effect on systolic function or aortic root diameters and a positive effect on heart rate, PWd, HRR-1, QTc and QTd time following nCPAP therapy

Hypoxia parameters, physical variables, and severity of obstructive sleep apnea

Objective: To determine the relation between hypoxia and physical parameters in patients who had different levels of severity of obstructive sleep apnea (OSA). Methods: This was a retrospective, cross-sectional study of 259 men who were evaluated with overnight polysomnography. Severity of OSA was graded based on the apnea-hypopnea index (AHI): normal/simple snoring (n=31); mild OSA (n=70); moderate OSA (n=63); severe OSA (n=95). Patients with different severity were divided into subgroups, based on having the lowest or highest values of the total sleep time with oxygen saturation <90% (ST90) or minimum oxygen saturation (min SaO(2)). Results: Median AHI was 20.4 events/hour. Univariate analysis showed that ST90 was correlated with AHI (r=0.772; p <= 0.001) and Epworth sleepiness scale (ESS) (r=0.344; p <= 0.001), and min SaO(2) was inversely correlated with AHI (r=-0.748; p <= 0.001) and ESS (r=-0.319; p <= 0.001). Multivariate linear regression showed that ST90 was independently associated with AHI, ESS, and neck circumference, and min SaO(2) was independently inversely associated with AHI, ESS, and body mass index (BMI). In patients who had severe OSA, the subgroups which had lowest and highest min SaO(2) differed significantly in BMI, modified Mallampati score, neck and waist circumferences, and ret-roglossal Muller grade. In patients with percentage of sleep time with oxygen saturation below 90% (CT90) <10%, the upper limit of ST90 was 36 minutes and corresponded to 70% lower limit of min SaO(2). Conclusion: Hypoxia parameters show significant variation in OSA severity categories. None of the physical parameters had clinically useful relations with hypoxia parameters in OSA patients except patients who had severe OSA