Key Points

In an LTAC population, infectious complications hindered weaning, increased the length of stay, and contributed to mortality. Premorbid functional status and residence influenced weaning outcomes and survival in the same population. Compared to chronically critically ill patients younger than 85, those 85 and older had significantly lower rates of weaning, survival to discharge, and one-year survival.

SAN DIEGO—If infections are the most prevalent complications at long-term acute care (LTAC) hospitals, as past data have indicated, how is that affecting the patients at those facilities who are being weaned from the ventilator? It could be extending their hospital stay, further prolonging their reliance on the ventilator, and, depending on the type of infection, greatly increasing their mortality.

Those were the implications from one of three studies of influences on weaning and survival among ventilator-dependent adults at Barlow Respiratory Hospital and Research Center, an LTAC facility in Los Angeles.¹ The results of the studies appeared as poster presentations at the annual meeting of the American Thoracic Society. Senior author of the studies, David J. Scheinhorn, MD, is Director of Research at Barlow.

In the first study, about 74% of the 186 patients admitted to Barlow’s post-ICU weaning program during a one-year period needed treatment for infections that were either present on admission or that developed during hospitalization. Thirty-two patients (17.2%) were treated for one infection and 106 (57%) were treated for two or more infections—primarily, urinary tract infection (UTI), pneumonia or tracheobronchitis, and Clostridium difficile colitis. There were substantially fewer cases of sepsis with or without shock, line sepsis, and aspiration pneumonia in the study population.

Forty-nine percent of the patients were successfully weaned; this took an average of 19 days. Twenty-two percent remained ventilator dependent, and 29% of the patients died.

Except for sepsis with or without shock, all of the infections found in the study population were associated with increased weaning time and length of stay. For example, the median weaning time for patients with and those without a UTI was 22 and 14 days, respectively. The median length of stay was 49 days when a UTI was present versus 27 days when it was absent.

Because they are more serious, pneumonia or tracheobronchitis, line sepsis, and the presence of two or more infections significantly increased mortality, as shown by respective odds ratios for death of 2.61, 3.52, and 3.19. Pneumonia or tracheobronchitis approximately quadrupled the chance of sepsis with shock, which was associated with an odds ratio for death of 30.1.

PREMORBID FUNCTIONAL STATUS AND RESIDENCE

Using the same population as the first study, the second study evaluated the relationships of premorbid functional status and place of residence to weaning outcomes and survival.² Surprisingly, the weaning outcome was similar whether the patients had good or poor premorbid functional status and whether they resided in an extended care facility or at home before their critical illness.

However, at one year postdischarge, survival was significantly lower for patients whose premorbid residence was an extended care facility than it was for those who previously lived at home. “That premorbid functional status and residence do not affect weaning outcome, including in-hospital mortality, is potentially important in making decisions in the ICU regarding continued efforts to wean from [prolonged mechanical ventilation],” remarked the authors.

Premorbid functional status was determined with the Zubrod Functionality Scoring System, a 6-point scale with scores ranging from 0 (fully active) to 5 (deceased). The authors defined good functional status as a Zubrod score of 0 to 2 and poor functional status as a Zubrod score of 3 or 4.

Of the patients with good premorbid functional status, 49% were weaned, 25% remained on the ventilator, and 26% died in the hospital. Those rates were 52%, 16%, and 31% for the patients with poor premorbid functional status.

One-year postdischarge survival was 43% for patients with good premorbid functional status compared to 28% for those whose premorbid functional status was poor. Forty-three percent of patients who lived at home before they became critically ill were alive after one year, versus 21% of those who had previously lived at an extended care facility.

OUTCOMES IN THE VERY ELDERLY, CHRONICALLY CRITICALLY ILL

The third study by Scheinhorn and colleagues,³ also conducted at Barlow, compared weaning outcomes and survival in 134 chronically critically ill patients (ie, those who remain ventilator dependent after a prolonged ICU stay) 85 or older and 800 such patients who were younger than 85. The older patients were less likely to be weaned (34% versus 49%) and more likely to die in the hospital (47% versus 32%).

Among the survivors, a greater percentage of the 85-and-older age-group required discharge to an extended care facility—85% versus 68% of the younger-than-85 group. One-year survival for the two groups was 22.5% and 45.4%, respectively. “These data, if replicated in other studies, with the addition of premorbid and resultant functional status and quality of life measures, will be useful in treatment decisions by elderly patients, their families, and physicians,” concluded the study authors.

—Timothy Begany

References
1. Scheinhorn DJ, Kim H, Hassenpflug M, LaBree L. Relationship of infectious complications to outcomes of weaning from prolonged mechanical ventilation. Presented at: annual meeting of the American Thoracic Society; May 24, 2005; San Diego, Calif.
2. Scheinhorn DJ, Hassenpflug M, Low S, LaBree L. Post-ICU mechanical ventilation: relationship of premorbid functional status and location to weaning outcome and survival. Presented at: annual meeting of the American Thoracic Society; May 24, 2005; San Diego, Calif.
3. Scheinhorn DJ, Hassenpflug M, Low S, LaBree L. Post-ICU mechanical ventilation: weaning outcomes and survival in the very elderly chronically critically ill. Presented at: annual meeting of the American Thoracic Society; May 24, 2005; San Diego, Calif.

Return to table of contents