[Outcomes and predictors of mortality in elderly patients requiring artificial ventilation]

We retrospectively examined the outcomes and the predictors of mortality in 97 patients aged 70 years and over (mean: 79.3 years) who required artificial ventilation for more than 3 hours. The median duration of artificial ventilation was 16 days (range: 1-85). Of these patients, 61% survived ventilator weaning and 37% were discharged from hospital alive. We performed univariate and logistic regression analysis to determine the predictors of dying before weaning and hospital discharge using severity of illness data. The predictors of hospital mortality were examined in 86 patients, excluding those who had malignant disease, all of whom died in hospital. Activities of daily living (ADL) were ranked as "bedridden", "in wheelchair", or "independent". In the three age groups-up to 70 years, 75 to 84 years and 85 years and over-the respective survival rates were 63% (weaned) and 67% (discharged), 69% (weaned) and 39% (discharged), and 33% (weaned) and 12% (discharged); the overall p values being 0.026 (weaned) and 0.003 (discharged). The predictors of dying before weaning according to univariate analysis were as follows: age (p = 0.026), respiratory or cardiac arrest on admission (p = 0.003), acute physiology score (APS) of 25 or more on admission (p = 0.000), systolic blood pressure below 90 mmHg on admission (p = 0.001), hemoglobin less than 11 g/dl (p = 0.044), and total protein less than 6 g/dl (p = 0.007). The predictors of hospital mortality by univariate analysis were as follows: age (p = 0.003), limited ADL (p = 0.001), respiratory or cardiac arrest on admission (p = 0.011), APS 25 or more on admission (p = 0.049), systolic blood pressure less than 90 mmHg on admission (p = 0.002), hemoglobin less than 11 g/dl (p = 0.028), and GOT or GPT more than 50 IU (p = 0.038). The relative risk of dying before weaning decreased in the order: respiratory or cardiac arrest on admission, systolic blood pressure less than 90 mmHg on admission, total protein less than 6 g/dl (Odds ratios: 6.04, 3.90, 3.51, respectively), or, respiratory or cardiac arrest on admission, APS more than 25 in admission, total protein less than 6 g/dl (Odds ratio: 6.94, 3.99, 3.76, respectively). The relative risk of hospital mortality decreased in the order: "bedridden", systolic blood pressure less than 90 mmHg on admission, "with wheel chair" (Odds ratios: 11.76, 6.44, 3.57, respectively). In the older patients, successful ventilator weaning was not indicative of hospital discharge. Ventilator weaning depended mainly on acute health status on admission, but hospital discharge depended also on the presence of limited ADL and preexisting malignant disease.