To examine predictors of ability to wean from mechanical ventilation (MV), functional ability and health-related quality of life (HRQoL) in patients who required prolonged mechanical ventilation (PMV) (≥ 7 days) six months after Medical Intensive Care Unit (MICU) discharge.
Consenting patients (n=145) completed questionnaires rating their functional ability (Health Assessment Questionnaire [HAQ]) one week before MICU admission (baseline), MICU discharge, 1 and 6 months post discharge and HRQoL (SF-36) at baseline, 1 and 6 months. Proxy responses of family members were used when patients could not respond.
At 6 months, 60.7% patients were living. Survivors were 55.7% female, 59.8± 16.7 yrs of age and on MV for 23.4± 22.5 days at MICU discharge. Complete sets of questionnaires were obtained from 52% patients for SF-36 and 72% for HAQ. At baseline, no differences were seen in SF-36 or HAQ scores. Patients on MV exhibited a statistically significant interaction between MV and Time (p=.034) with higher HAQ scores (worse functional ability) at 1, but not 6 months. SF-36 physical component scores were lower (worse ratings) at 1 (p=.003), but not 6 months. No significant changes were seen in SF-36 mental component scores. Using logistic regression, cormobidity was identified as a significant predictor of ability to wean from MV following MICU discharge (71.4% cases correctly predicted). Age, gender, APACHE III, baseline HAQ and SF-36 scores were not identified as significant predictors.
PMV survivors rate HRQoL similarly 6 months after MICU discharge, regardless of ability to wean from MV. Those not weaned from MV were more compromised in functional ability at 1, but not 6-months. Cormorbidity was the best predictor of ability to wean following MICU discharge.
Inability to wean from PMV does not appear to influence ratings of HRQoL 6 months after MICU discharge. Potential reasons include changes in reference point (expectations) or lack of instrument sensitivity. Cormorbidity significantly influences ability to wean following MICU discharge.
Leslie Hoffman, None.