Nocturnal Oxyhemoglobin Desaturation and Prognosis in Chronic Obstructive Pulmonary Disease and Late Sequelae of Pulmonary Tuberculosis

We prospectively examined the survival rate of 67 chronic obstructive pulmonary disease (COPD) and 74 late sequelae of pulmonary tuberculosis (TB seq) patients to clarify whether nocturnal oxyhemoglobin desaturation (NOD)could be one of the independent factors determining their mortality. The sleep monitoring of arterial oxygen saturation (SpO2) and pulmonary function tests were assessed in all patients at the time of registration. Forty %of COPD and 24%of TB seq died as the direct result of deterioration of chronic respiratory failure during the 7-year observation period. Cox's proportional hazards analysis showed that NOD was an independent prognostic factor in both groups, and this was especially prominent when evaluated in terms of sleep lowest SpO2 in COPD and 85% desaturation time in TB seq. No significant prognostic factor was observed among age, vital capacity percent predicted (%VC), forced expiratory volume in one second (FEV1.0%)and partial pressure of carbon dioxide (PaCO2). We conclude that the degree of NOD can affect mortality in COPD and TB seq.(Internal Medicine 37: 354-359, 1998)