Severe BOOP

Background

A subgroup of BOOP has recently emerged as an important cause of severe respiratory disease which is often progressive and is associated with a significant morbidity and mortality.

Methods

Retrospective and prospective study of ten patients with respiratory failure due to histopathologically confirmed BOOP. End points included determination of markers for severe BOOP, outcome and follow up. Patient demographics, clinical, radiographic and laboratory features, necessity for mechanical ventilation, therapy, associations and hospital stay were also reviewed.

Results

The median age of the study group was 41.5 years (range 7–62) and included five males and five females. Five (50%) required mechanical ventilation. Three (30%) demised in hospital and one died following hospital discharge. Overall mortality was 40%. The median PaO₂/FiO₂ ratio for the whole group was 139 (range 61–250) with the median LDH level, on admission, 612 μ/l (range 375–2638). Those patients who were discharged from hospital had a median LDH level of 521 μ/l (range 375–1599) versus a median level of 2154 μ/l (range 2100–2638) for those who died in hospital (P = 0.016). Patients who required mechanical ventilation had a median LDH level of 2100 μ/l (range 691–2638) versus a median LDH level of 504 μ/l (range 375–534) for non-ventilated patients (P = 0.008). The most common chest radiographic appearance was a mixed alveolar-interstitial pattern in six patients (60%). In addition to the characteristic histopathological features of BOOP, this group of patients universally demonstrated alveolar septal expansion. Increased reticulin was also noted. The median hospital stay was 25 days (range 9–127) with follow up ranging from one to 28 months.

Conclusion

BOOP may manifest as a severe illness with an associated significant morbidity and mortality. LDH may be useful as a marker of disease severity and outcome.