Respiratory variable predictors for intensive care mortality
© Biomed central limited 2001
Published: 21 March 2006
Nowadays it is not clear whether the level of hypoxemia is related to the outcome. It has been shown that the pulmonary dead space fraction is an independent risk factor for death in the early phase of acute respiratory distress syndrome .
We aimed to study possible respiratory predictors for mortality in mechanically ventilated patients.
Materials and methods
Consecutive patients invasively mechanically ventilated for more than 48 hours were enrolled. At ICU admission blood gas exchange and the ventilatory setting were recorded.
Sixty-eight patients (45 males, mean age 59.6 ± 15.5 years, weight 71.6 ± 14.1 kg) were enrolled at one ICU from October 2004 to October 2005. Thirty-seven patients presented acute lung injury or acute respiratory distress syndrome during their intensive care stay.
The overall intensive care mortality was 23% (16 patients). The blood gas analysis showed a mean PaO2/FiO2 ratio of 207 ± 120 mmHg, PaCO2 of 37 ± 10 mmHg and pH of 7.34 ± 0.13 with the following ventilatory setting: PEEP 8.1 ± 4.6 cmH2O, respiratory rate 17.8 ± 5.2 bpm, tidal volume 662 ± 145 ml and minute ventilation 9.1 ± 2.0 l/min. Among the respiratory variables considered only the PaCO2 was associated with an increased intensive care mortality (OR 1.08, 95% confidence interval 1.021–1.152).
The increase in PaCO2, reflecting a higher degree of pulmonary impairment, was associated with intensive care mortality.