ABSTRACT
The study aim was to compare the mortality risk of men and women diagnosed with obstructive sleep apnoea (OSA) and started on treatment with continuous positive airway pressure (CPAP). From August to December 2003 we reviewed the hospital records of patients who had started on CPAP for OSA between July 1995 and June 1998. Mortality rates were compared between men and women. Associations with mortality risk were determined using univariate and multivariate Cox's proportional hazards regression. The sample comprised 292 men and 47 women. Eight percent of the men and 23% of the women died (p=0.003). Univariate analysis showed increased mortality risk was associated with female sex, greater age when CPAP was started, a pre-treatment minimum nocturnal oxygen saturation (SpO(2)) <75%, a higher Charlson comorbidity index score and discontinuation of CPAP treatment. Female sex remained associated with increased mortality independent of age, minimum SpO(2) and CPAP use, but was not independent of the Charlson score. Women diagnosed with OSA and treated with CPAP demonstrated a 3.44 greater mortality risk than men, mostly due to greater comorbidity.
Subject(s)
Sex Factors , Sleep Apnea, Obstructive/mortality , Age Factors , Analysis of Variance , Comorbidity , Continuous Positive Airway Pressure , Female , Humans , Male , Middle Aged , Oxygen/blood , Polysomnography , Proportional Hazards Models , Retrospective Studies , Risk Factors , Sleep Apnea, Obstructive/diagnosis , Sleep Apnea, Obstructive/therapy , Survival RateABSTRACT
Differences between bilevel ventilators used for noninvasive intermittent positive pressure ventilation (NIPPV) have been demonstrated during bench testing. However, there are no clinical studies comparing these machines. The authors have previously shown that the Quantum pressure support ventilator and Sullivan variable positive airway pressure II ST differ in performance during bench testing. To examine the clinical significance of this, these two machines were compared in the overnight treatment of subjects with chronic respiratory failure. Ten clinically-stable subjects with thoracic scoliosis were recruited. The subjects were already established on NIPPV, but none were using either of the ventilators to be tested. After familiarisation, the patients used the two ventilators in random order on consecutive nights. Peripheral oxygen saturation and transcutaneous carbon dioxide tension (Pt,CO2) were measured continuously, and sleep was recorded using polysomnography. There were no significant differences in arterial oxygen saturation, Pt,CO2 or sleep duration and quality between the two nights. Despite previously illustrated variation in laboratory performance, no differences were seen between the two ventilators when comparing overnight gas exchange and sleep in vivo. Further study is required to evaluate the significance of the differences found during bench testing in the clinical setting.
Subject(s)
Positive-Pressure Respiration/instrumentation , Respiratory Insufficiency/therapy , Scoliosis/complications , Sleep Wake Disorders/therapy , Ventilators, Mechanical , Adult , Aged , Chronic Disease , Female , Follow-Up Studies , Humans , Intermittent Positive-Pressure Ventilation/instrumentation , Intermittent Positive-Pressure Ventilation/methods , Male , Middle Aged , Oximetry , Positive-Pressure Respiration/methods , Probability , Prospective Studies , Pulmonary Gas Exchange , Respiratory Insufficiency/etiology , Sampling Studies , Scoliosis/diagnosis , Sensitivity and Specificity , Severity of Illness Index , Sleep Wake Disorders/diagnosis , Sleep Wake Disorders/etiology , Treatment OutcomeABSTRACT
BACKGROUND: It is widely believed that patients with narcolepsy show high rates of associated psychiatric disturbance, especially schizophrenia and depression. However, surveys have produced conflicting findings and have not addressed the potential confounding effects of stimulant drug treatment. METHOD: Forty-five patients with narcolepsy attending a sleep disorder clinic and 50 matched normal controls underwent structured psychiatric interview. Using a 'lifetime' approach, psychiatric symptoms and diagnoses were established for both groups. RESULTS: Four of the narcolepsy patients but none of the controls had experienced psychotic symptoms. All four patients were taking amphetamines, and the symptoms resolved when the dose was lowered or treatment was changed to modafinil. The lifetime frequency of various depressive syndromes did not differ significantly between the groups. CONCLUSIONS: Contrary to previous claims this study found little to suggest that narcolepsy is associated with schizophrenia. Nor, despite its serious social and occupational consequences, does narcolepsy appear to be associated with an increased frequency of diagnosable depressive disorders.
