Post-ICU Mechanical Ventilation
Abstract & Commentary
Synopsis: More than half of the ventilator-dependent patients transferred from acute-care hospitals to a specialized, long-term weaning unit were successfully weaned, and almost that many lived at least one year after discharge.
Source: Scheinhorn DJ, et al. Chest 1997;111: 1654-1659.
During an eight-year period, scheinhorn and colleagues accepted 1123 ventilator-dependent patients in transfer from acute-care hospitals to their regional weaning center. This paper describes the patient population and reports on the rates of successful weaning, death, discharge, and one-year survival observed. Data were gathered retrospectively from admissions during the first six years and prospectively thereafter.
The patients’ ages were 69 ± 13 years, and 57% were women, without significant variation throughout the reporting period. Primary diagnoses likewise remained constant; chronic lung disease in 28% of patients, acute lung disease in 29%, and postoperative complications in 23%. There was a trend toward increased severity and complexity of illness with time, however, as shown by significantly shorter periods of pre-transfer ventilation (from a median of 37 days in 1988 to 29 days in 1996), increased P(A-a)O2 at the time of transfer, lower serum albumin levels, and a higher frequency and severity of pressure ulcers at the time of transfer.
Despite these indicators of increased severity of illness at the time of transfer, patient outcomes remained unchanged throughout the eight-year period. Successful weaning was achieved in 55.9% of patients; 15.6% failed to wean, and 28.8% died at the weaning center. The 29-day median time to completion of weaning also did not change. Overall, one-year survival after discharge from the center was 37.9%; there was an increase in this figure from 29% in 1988-91 to 45% in 1992-96. During these respective time periods, one-year survival among patients who were weaned and discharged to home was 45% and 59%.
Scheinhorn et al conclude that ventilated patients are now being transferred to their center from ICUs earlier in their courses of prolonged critical illness and with greater severity of illness. Overall mortality and the proportion of patients successfully weaned have not changed, although more patients discharged home are surviving one year.
COMMENT BY DAVID J. PIERSON, MD
In this article, Scheinhorn et al at the Barlow Respiratory Hospital update their previous report (Scheinhorn DJ, et al. Chest 1994;105:534-539) on the demographics and outcomes of patients transferred to their specialized regional weaning center from acute-care hospitals in Los Angeles. Although several chains of for-profit subacute care facilities in the United States have probably accumulated aggregate experiences of even more patients than described here, to my knowledge this is by far the largest report of clinical data gathered systematically and subjected to peer review in the burgeoning area of post-ICU management of ventilator-dependent patients.
The expertise demonstrated by the Barlow group in this specialized area of critical care is indeed impressive, as are the clinical outcomes in their patients; eventual complete weaning from ventilatory support in more than half of all patients, with one-year survival of nearly 50% in all discharged patients, despite these individuals having been more seriously ill on transfer than when the unit opened eight years ago. Does this mean that ventilated patients sent from acute-care hospitals to other facilities will do as well? Unfortunately, it does not.
This paper lends further support to the concept that patients who remain ill enough to require continued mechanical ventilation and other technological support after initial recovery from critical illness can be managed successfully at sites other than the ICU. A main reason that many such patients are now being cared for at such sites is economic, as reviewed one year ago in these pages by Rubenfeld (Critical Care Alert 1996;4:47-48). Such alternate-site patient care varies in intensity and goes by several names depending on the type of facility in which it occurs (whether step-down unit in acute-care hospital, free-standing specialized long-term acute-care facility, rehabilitation center, or skilled nursing facility), which does not aid in understanding the issues involved or in assessing the quality and costs of care.
As a result, ICU clinicians need to be familiar with both the levels of care and the caliber of this care in the nearby sites to which their patients might be transferred. Rates of successful weaning and one-year, post-discharge survival similar to those reported by Scheinhorn et al may be far beyond the capabilities of a given facility, depending on what patients it accepts, how well it is staffed, how up-to-date its practices are, and many other factors in the complex area of post-ICU care.