Early reliable identification of patients with Pneumocystis carinii pneumonia (PCP) who will require ventilatory support would be desirable. To develop a predictive system to meet this need, we studied, prospectively, the sequential alterations in vital signs and acid-base and blood-gas profiles associated with this disease in 55 children with cancer, 29 of whom did not require ventilatory support (Group I) and 26 who did (Group II). None of the patients had acquired immunodeficiency syndrome (AIDS). On admission to the hospital the only feature that distinguished patients in Group I from those in Group II was the mean (± SD) respiratory rate (38.7 ± 2.1 versus 49.1 ± 3.5 breaths/min, p < 0.02). By 12 h after admission there was a significant difference in the partial pressure of oxygen (Pa(O2)) between Groups I and II (75.1 ± 3.2 mg Hg versus 65.4 ± 3.1 mm Hg, p < 0.05), and also in the two groups' inspired fraction of oxygen (FIO2; 24.9 ± 0.54% versus 29.6 ± 1.6%, p < 0.01). Both alterations, as well as tachypnea, persisted for the remainder of the study period. The maximum FIO2 did not exceed 45% in Group I, and by 60 h after admission to the hospital, all patients in this group had persistent increases in Pa(O2) that exceeded 80 mm Hg, permitting decreases in FIO2 to that of room air. In Group II, hypoxemia was refractory despite an increase in FIO2 to 50%, at which point ventilatory support was begun (at a mean of 81.1 ± 32.3 h after admission). Discriminant-function analysis of the vital signs and blood-gas and acid-base measurements in these patients allowed us to devise a scoring system to predict the need for ventilatory support during the course of PCP. Scores based on information collected at 36 h after admission would have identified with 91% success those patients who required ventilatory support. These findings demonstrate distinctive alterations in respiratory rate and arterial oxygenation associated with PCP in children with cancer without AIDS who subsequently require ventilatory support. The proposed scoring system, after validation in other patient cohorts with PCP associated with either AIDS or other immunosuppressive diseases, may permit more timely decisions regarding early hospitalization and supportive therapy, which may be lifesaving.
|Original language||English (US)|
|Number of pages||7|
|Journal||American journal of respiratory and critical care medicine|
|State||Published - Jan 1 1994|
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Critical Care and Intensive Care Medicine