The Utility of Open Lung Biopsy in Patients Requiring Mechanical Ventilation: Conclusion
The initial management of patients with acute pulmonary infiltrates and respiratory failure is an area of much deliberation within the environment of the ICU. Patients are often treated with empirical antimicrobial medications. These may be added in the setting of existing corticosteroid and/or other immunosuppressive medications. The open lung biopsy can direct the withdrawal of otherwise empirical therapy and provide a basis for limiting prolonged and otherwise unnecessary intensive care therapy. The expected withdrawal-of-therapy rate after an open lung biopsy would depend greatly on the group of patients examined. Hiatt et al determined that 62% of their study group of immunosup-pressed patients with predominantly hematological malignancies had nontreatable disease. While studying a group of patients with diffuse pulmonary infiltrates and acute respiratory failure (25% of whom required mechanical ventilation), Warner et al found an open lung biopsy withdrawal-of-ther-apy rate of 7.5%, a rate comparable to the 8.4% of all patients in this current study.
As an investigative tool in critically ill patients, the open lung biopsy is an infrequently performed procedure with a maximal yearly incidence of 0.9% during the time period for this study. This low incidence limits the power of such a study, as do any confounding factors that may have developed during that time frame. However, this number is similar to other studies that have documented 20 and 31 patients with respiratory failure requiring mechanical ventilation in a 10-year period, although one study involved 27 such patients in a 6-year period.
Haverkos et al studied 59 patients in ICU (need for mechanical ventilation not stated) over an 8.5-year time frame. In the latter study, there was an increase in the proportion of patients who were not immuno-suppressed and undergoing an open lung biopsy. There was no identifiable trend for the use of an open lung biopsy in our study. purchase antibiotics online
In conclusion, this retrospective 10-year study of patients in the ICU with undiagnosed diffuse pulmonary infiltrates requiring mechanical ventilation showed that an open lung biopsy can provide a specific diagnosis in at least 46% of cases. Of the patients with a specific diagnosis, in whom the open lung biopsy guided a specific therapeutic alteration, 36% survived until discharge from the hospital. The biopsy also led to the withdrawal of therapy in another 9% of this group. Mortality and morbidity rates associated with open lung biopsy in this and one other study of mechanically ventilated patients were higher than in the studies involving nonventilated patients. Thus, the careful selection of patients for open lung biopsy is crucial in overall clinical use and whether the patient will benefit from this procedure should be considered. Generally, as indicated by this study, patients with respiratory failure requiring mechanical ventilation with a higher multiple organ dysfunction score (MODS) tend to die from MSOF despite the open lung biopsy histological findings and open lung biopsy-directed therapeutic alterations.