Acute respiratory failure due to Pneumocystis carinii pneumonia: clinical, radiographic, and pathologic course

[Pneumocystis jirovecii pneumonia in non-HIV infected patients: a study of 41 cases]

BACKGROUND

The increasing use of immunosuppressive and cytotoxic therapies leads to a growing number of opportunistic infections especially Pneumocystis jirovecii pneumonia (PCP). The purpose of our study was to describe the population involved, and to assess clinical, biological, and mortality data.

METHODS

We collected retrospectively the whole medical file of all PCP cases diagnosed in non-HIV infected patients, in two French University Hospitals in the last decade (1999-2009). Diagnosis was made on standard coloration and/or immunofluorescence analysis of bronchoalveolar lavage fluid (BAL).

RESULTS

Forty-one patients were included in the study, mean age 56 (±12.5) years, sex ratio 0.71 men/woman. Underlying diseases were as follow: 12 patients (29%) were renal transplant recipients, 13 (32%) were treated for solid cancers, and 16 (39%) suffered from various diseases (three allogenic bone-marrow transplantation, 11 hematological malignancies, one pulmonary transplantation, one vasculitis). Twelve patients died (i.e. 29%). Median lymphocyte count was 542/mm(3). More than 85% patients received corticosteroids at a median cumulative 6-month dose of 2700mg. Seven patients (17%) had a PCP prophylaxis. Clinical worsening at day 5 (P<0.003), poor control of the underlying disease (P<0.015), WHO performans status superior than 2 (P<0.025), high temperature (P<0.04), and high oxygen flow (P<0.042) were linked to a poor prognosis.

DISCUSSION/CONCLUSION

The prognosis factors found are mostly linked to the patients' clinical severity. We would like to highlight: first, near to 30% mortality rate, secondly, a lack of prophylaxis in 34 patients, reflecting the difficulty to define PCP's risk in non HIV-infected patients.

Acute respiratory distress syndrome

The acute respiratory distress syndrome (ARDS) is a serious and complex clinical problem that often threatens the lives of patients. Emerging clinical data suggest that the survival of patients with this disorder may have improved during the last two decades, presumably because of advances in supportive medical care. Among the supportive therapies used to treat patients with ARDS, none is more complex than mechanical ventilation. New strategies for administering mechanical ventilation to patients with ARDS may reduce the occurrence of iatrogenic volotrauma and oxygen toxicity, accounting in part for the recently observed improvements in patient survival. Prevention and cure of ARDS have remained elusive goals because of the lack of specific therapies directed against the known pathogenic factors. Ongoing investigations are aimed at identifying specific therapies to interrupt the mechanisms of inflammation and lung injury responsible for this syndrome. Until such therapies become available, clinicians caring for patients with ARDS should attempt to minimize additional morbidity and mortality resulting from nosocomial infections and iatrogenic injuries.

The acute respiratory distress syndrome

ARDS is a complex response of the lung to direct (inhalational) and indirect (hematogenous) insults. It is easy to be pessimistic about the benefit of the approaches we have described, but there is evidence that overall survival has improved in recent years. To maintain this progress, new therapies for ARDS must be rigorously evaluated, and their routine use should be recommended only after careful scrutiny of the evidence. Such a course will eliminate the unnecessary risks and costs often associated with unproved therapies.

Pneumocystis carinii pneumonia during steroid taper in patients with primary brain tumors

Pneumocystis carinii causes life-threatening pneumonitis (PCP) in immunocompromised individuals. In the non-AIDS (acquired immunodeficiency syndrome) population, PCP is frequently associated with corticosteroid therapy, and the rodent model uses corticosteroid-induced immunosuppression to provoke PCP. Although patients with intracranial tumors are frequently treated with long courses of corticosteroids, there have been very few descriptions of PCP in this population. We report the diagnosis and treatment of PCP in four patients over a 12-month period with intracranial neoplasms who developed symptoms during corticosteroid taper. Effective prophylaxis against PCP exists and should be considered for patients with intracranial neoplasms receiving long-term steroids.

Improved survival in patients with AIDS, Pneumocystis carinii pneumonia, and severe respiratory failure

Pneumocystis carinii pneumonia (PCP) causing acute respiratory failure (ARF) in patients with acquired immunodeficiency syndrome (AIDS) has been reported in several studies to have a mortality of 84 to 100 percent. A recent report found a 42 percent survival rate. We followed 58 patients with AIDS who required positive pressure ventilation and identified 33 patients with PCP and ARF who had a PaO2/FIo2 level less than 150 mmHg. We report the survival of 12 of these 33 (36 percent). The mean duration of survival after discharge from the hospital was 7.9 +/- 1.8 months, which is an improvement over previous reports. These data suggest that we should reevaluate the reported recommendations that patients with AIDS, PCP and ARF should not receive intensive care or mechanical ventilation.

Long-term prognosis of survivors of Pneumocystis carinii pneumonia. Structural and functional correlates

Limited data exist detailing the long-term sequelae of Pneumocystis pneumonia. Open lung biopsies were obtained in seven renal transplant recipients within 48 hours of the onset of respiratory failure. Biopsy specimens and simultaneous chest roentgenograms were graded without clinical information according to the severity of alveolar damage and pulmonary infiltrates, respectively. Evaluation of pulmonary function and exercise physiology were performed 15 to 21 months after their illness. Pulmonary function indices were normal except FRC (2.65 +/- 0.56 L or 77 +/- 16 percent of predicted) and Dsb (20.0 +/- 7.2 ml/min/mm Hg or 79 +/- 19 percent of predicted). Two patients developed arterial desaturation with exercise. Alveolar damage scores correlated with later exercise arterial desaturation (r = 0.88, p less than 0.05). Simultaneous roentgenographic scores correlated with later abnormalities of Dsb (r = 0.81, p less than 0.05). Mild residual abnormalities of pulmonary function were found in five of seven adult survivors of Pneumocystis pneumonia. These abnormalities correlated with pathologic and radiographic features of the acute illness.