Severe nocturnal hypoxaemia in geriatric inpatients

Background: oxygen levels are decreased in older people especially in the supine position, and during sleep. Geriatric inpatients often suffer from stroke and heart disease. Respiratory control may be substantially affected. Objective: the aim of this study was to examine oxygen levels during night in inpatients on geriatric medical wards to find out if they needed nocturnal oxygen therapy. Design: prospective observational study. Setting/Participants: we consecutively examined 133 patients with SpO(2) >= 92% in sitting position by an overnight -8-h pulse oximetry. Patients with severe obesity, dementia or pulmonary disease were excluded. The test was performed at least 4 days after the event in stroke cases. Outcome Variables: ninety two patients, m/f 43/49, with mean age 78.3 +/- 6.9 SD completed the test. Sixty six patients suffered from stroke; 34 left-sided and 19 right-sided stroke. Nine patients suffered from a heart disease only, and 17 patients suffered from other diseases. Results: according to the guidelines for long-term oxygen therapy recommendations for nocturnal oxygen therapy, we found that 26% of the patients fulfilled the criteria of SpO(2) <= 90% for >= 30% of the time. There was a significant positive correlation between age and the amount of time with SpO(2) between 80 and 84% (0.215, P<0.05). Diagnosis or severeness of disease did not significantly affect nocturnal SpO(2) %. The 1-year survival rate was 75% in group I (hypoxaemic) versus 84% in group II (normoxaemic) (NS). Conclusion: nearly 30% of the inpatients in geriatric medical wards suffered from severe oxygen-requiring nocturnal hypoxaemia irrespective of diagnosis.