Table 2 Alternative diagnosis in patients with negative bacterial growth BAL result

Viral

26

Pneumocystis jirovecii

7

Fungal

6

Heart failure

4

Bronchiolitis obliterans organizing pneumonia

3

Usual interstitial pneumonia

1

All trans retinoic acid (ATRA) syndrome

1

Pulmonary embolism; obstructive shock

2

Endocarditis

1

Abdominal sepsis with ARDS

4

Necrotizing pancreatitis

2

Abdominal ischaemia

1

Urinary tract sepsis with ARDS

2

Ovarian cancer with pulmonary metastases

1

Systemic lupus erythematosus

1

Toxic epidermal necrolysis

1

Postanoxic encephalopathy with multiple infarction

1

Myasthenia gravis

1

None established

31