One week of freedom from ventilator support (VS) is considered to be the criterion for successful weaning. For patients in long term acute care (LTAC) VS programs, however, four weeks of freedom may be a more appropriate criterion. This study was to compare the survival of patients who were weaned from VS for more than one but less than four weeks to patients who remained ventilator free for more than four weeks.
All patients admitted to this 627-bed DRG-exempt LTAC hospital in 2001 and 2002 on a ventilator (n=367) were assessed by staff pulmonologists for weanability. Measures recorded were: a) alive or dead, at discharge or on 31th of March 2003; b) number of patients free from VS for at least four consecutive weeks; c) number of patients free from VS for at least one but not for four weeks.
Of the 116 patients liberated from VS for four consecutive weeks, 91 (85%) were alive and 25 (15%) were dead. Of the 19 patients liberated from VS for one but less than four weeks, 3 (15%) were alive and 16 (85%) were dead (p < 0.0001; Chi-square test). Time-to-event (death, return to ventilator) analyses likewise showed significant differences between these two groups (p < 0.001; log-rank test).CONCLUSIONS: Although deemed unweanable in the acute care hospital, many patients referred to LTCA VS programs have been successfully weaned. The one-week free from VS criterion is less satisfactory than four weeks of freedom for this patient population.
When the four-week free from VS criterion is used as measure of successful weaning a better survival can be predicted. Patients liberated from VS for at least four weeks appear to be more clinically stable than those liberated for one but not for four weeks. It seems, therefore, reasonable to use this criterion for successful weaning of long-term ventilator patients deemed unweanable in acute care general hospitals.
G.R. Sansone, None.