Authors: Shaddock E, Richards G, Murray J
Source: South Afr Res J 2009; 15(3):105
In the developed world in the HAART era, even though declining, respiratory failure is still the single most common reason for ICU admission.1 Before the antiretroviral rollout in South Africa in late 2003 many ICU’s had policies excluding ventilation for patients with respiratory failure due to pneumocystis pneumonia. However after the ARV roll out it seemed appropriate to consider these patients for mechanical ventilation. With the above in mind the 576 ICU at Johannesburg Hospital started to accept and ventilate patients with pneumocystis pneumonia.
The prognosis of patients with PCP who require ventilation is poor. Studies evaluating mortality amongst these patients range from 36% to 80%.2,3 The more recent studies have shown improved outcomes due to adjunctive corticosteroids, improved ICU care and ARV’s.1,4,5
In the 576 ICU experience we found that even with ARDSNET ventilation strategies, glucose control and early initiation of corticosteroids, the mortality was 100%. To see if we could improve our outcomes we performed postmortem trucut lung biopsies on our patients.
We were able to collect specimens from seven patients over the period 3/4/8 until 13/4/9. The biopsies revealed the usual changes seen with pneumocystis jirovecii. Air spaces filled with frothy pink hyaline material with intact alveolar architecture and type 2 pneumocyte hyperplasia. Two of the seven also had evidence of concurrent CMV infection. The histology also revealed interstitium expansion with reticulin and collagen fibrosis, all in keeping with interstitial fibrosis. Although this has been noted in the past, recent publications have not indicated that this remains a problem.
We postulate that the reason for the continuing poor outcome in these patients is due to this underlying fibrosis. And similar to patients with ARDS fibrosis, have a poor outcome. We must therefore consider new forms of treatment to try and modulate the development of the interstitial fibrosis.