Choice of therapy was determined by the individual physicians caring for the patient. Seventy-eight percent (117 patients) of those with PCP survived their initial episode. Among surv ivors 40 of the 117 patients successfully completed a three-week course of trimeth-oprim-sulfamethoxazole (TMP-SXT). The remaining successfully treated 77 patients initially received TMP-SXT but were switched to pentamidine therapy because of toxic reactions (30 patients) or failure to improve within five days of initiation of TMP-SXT therapy (47 patients). Among the 33 nonsurvivors, 27 initially received TMP-SXT but were switched to pentamidine because of clinical deterioration, while seven patients received only pentamidine. Serial serum LDH and P(A-a)02 gradients were obtained in 50 patients who survived their initial episode. Samples were obtained on days 1, 10, and 17 of therapy. read more
All data are presented as their mean ± SD. To evaluate whether two independent groups of values were statistically equivalent, the Students t test was used, and one-sided p values were obtained. The sensitivity and specificity were calculated utilizing the following formulas:
Fever, cough, and dyspnea occurred in 97 percent, 86 percent, and 76 percent of group 1 patients vs 90 percent, 90 percent, and 72 percent of group 2 patients (p = NS). Table 1 lists the admission physical and laboratory findings of both groups. The only significant differences were the presence of inspiratory crackles (greater in pulmonary processes other than Pneumocystis), the presence of diffuse interstitial infiltrates (greater in non-PCP patients), the increased P(A-a)Os gradient, as well as the elevation in serum LDH (greater in PCP patients). The mean serum LDH (normal ^220 IU/L) was 465 ±67 IU/L in group 1 patients with PCP vs 211 ± 28 IU/L in group 2 patients with non-PCP pulmonary processes (p<0.01) (Fig 1).
Figure 1. Admission serum LDH was significantly elevated in patients with Pneumocystis carinii pneumonia (p<0.01) in contrast to AIDS patients with other types of pneumonias, as well as AIDS patients with nonpulmonary manifestations.