Open lung biopsy in patients on mechanical ventilation with suspected diffuse lung disease.

Background: While open lung biopsy (OLB) performed in patients on mechanical ventilation (MV) with diffuse lung diseases (DLD) can be extremely important in establishing the diagnosis, the associated risk of this procedure should be taken into account.

Aim: To determine the diagnostic yield, therapeutic changes, complications and mortality in patients with DLD on MV submitted to OLB.

Methods: Retrospective study of 19 patients admitted to S. João Hospital between January 1999 and July 2007 (8.5 years). Data analysed included demographic data, ventilation variables before and after biopsy, diagnostic yield, effect on subsequent treatment changes and complications of OLB. Statistical analysis was performed using SPSS 14.0.

Results: The mean age of patients was 58+/-16.3 years old and 53% were male. The mean duration of hospital stay in Intensive Care Unit before performing OLB was 13+/-7 days. All biopsies were performed by thoracotomy. The diagnostic yield was 95%. There were no significant differences in partial pressure of arterial oxygen/fraction of inspired oxygen (PaO(2)/ FiO(2)) ratio and the positive end expiratory pressure (PEEP) before and after OLB. Postoperative complications occurred in 4 patients (21%; persistent air leak). Alteration in the diagnosis occurred in 14 patients (74%) and in 8 patients (42%) there was a modification in the treatment regimen. Global mortality was 47% (9 patients) but there were no biopsy-related deaths.

Conclusion: The high diagnostic yield and the low incidence of complications make OLB a useful procedure in patients on MV with DLD of unknown aetiology. However, early OLB may lead to even better results in some patients.