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Introduction: Noninvasive pressure support ventilation (NIPSV) and continuous positive airway pressure (CPAP) are both advocated in the treatment of cardiogenic pulmonary edema (CPE); however, the superiority of one technique over the other has not been clearly demonstrated. With regard to its physiological effects, we hypothesized that NIPSV would be better than CPAP in terms of clinical benefit., Methods: In a prospective, randomized, controlled study performed in four emergency departments, 200 patients were assigned to CPAP (n = 101) or NIPSV (n = 99). Primary outcome was combined events of hospital death and tracheal intubation. Secondary outcomes included resolution time, myocardial infarction rate, and length of hospital stay. Separate analysis was performed in patients with hypercapnia and those with high B-type natriuretic peptide (>500 pg/ml)., Results: Hospital death occurred in 5 (5.0%) patients receiving NIPSV and 3 (2.9%) patients receiving CPAP (p = 0.56). The need for intubation was observed in 6 (6%) patients in the NIPSV group and 4 (3.9%) patients in the CPAP group (p = 0.46). Combined events were similar in both groups. NIPSV was associated to a shorter resolution time compared to CPAP (159 ± 54 vs. 210 ± 73 min; p < 0.01), whereas the incidence of new myocardial infarction was not different between both groups. Similar results were found in hypercapnic patients and those with high B-type natriuretic peptide., Conclusions: During CPE, NIPSV accelerates the improvement of respiratory failure compared to CPAP but does not affect primary clinical outcome either in overall population or in subgroups of patients with hypercapnia or those with high B-type natriuretic peptide.

Objective: To evaluate the diagnostic agreement between quantitative cultures of samples obtained with endotracheal aspiration (ETA) and plugged telescoping catheter (PTC)., Design: Prospective study., Setting: Medical ICU., Patients: Hundred thirty-eight episodes of suspected ventilator-associated pneumonia studied in 100 consecutive patients., Interventions: For each suspected episode of ventilator-associated pneumonia, ETA and PTC were performed consecutively. The agreement between microbiological results obtained from the two techniques was evaluated (kappa statistic test). Pneumonia was diagnosed on a positive culture result of telescoping catheter with the threshold set at 10(3) cfu/ml or more. The cut-off points evaluated for ETA ranged from 10(2 )to 10(6) cfu/ml., Results: Micro-organisms retrieved by aspiration and telescoping catheter were similar and bacterial counts obtained by the two procedures were well correlated ( r = 0.71 p < 0.001). There was good agreement between positive and negative ETA and PTC specimens (kappa: 0.78) with a diagnostic threshold for ETA of 10(4) cfu/ml. The sensitivity and specificity of ETA for the diagnosis of PTC-confirmed pneumonia were 92% and 85%, respectively. Kappa decreased to 0.48 when the diagnostic threshold was increased to 10(6) cfu/ml., Conclusions: Quantitative cultures of ETA and PTC tallied for both micro-organisms and counts. The simpler ETA appears adequate for determining the presence of pathogenic organisms in significant concentration in the lower respiratory tract.

Objective: To evaluate the effects of scorpion venom and antivenom in experimental envenomation., Design: Prospective, controlled animal study., Setting: University research laboratory, Subjects: Twenty-nine anesthetized and ventilated dogs., Interventions: The first group of animals had venom alone (0.05 mg/kg). Animals from the second group had simultaneous administration of 10 ml of scorpion antivenom (SAV). In the third and fourth groups, 10 ml and 40 ml SAV, respectively, were injected 10 min following venom., Measurements and Results: Hemodynamic parameters using right heart catheter were recorded and dosage of catecholamines, neuropeptide Y (NPY), endothelin-1, and atrial natriuretic peptide (ANP) were performed at baseline and during 60 min following envenomation. In the control group, at 5 min, there was a sharp increase in pulmonary artery occluded pressure (PAOP, from 2 mmHg to 23 mmHg), mean arterial pressure (MAP, from 125 mmHg to 212 mmHg) and systemic vascular resistance (SVR, from 2450 dyn sec(-1 )m(5) to 5775 dyn sec(-1 )m(5), P<0.05 for all). Heart rate, cardiac output, and stroke volume decreased. There was a 40-fold increase in epinephrine and norepinephrine plasma concentrations. Circulating NPY and ANP dosages increased too. PAOP and MAP decreased thereafter to reach baseline levels. Simultaneous administration of SAV with venom totally offset the hallmarks of scorpion envenomation. Delayed administration of SAV at any dosage failed to alter the features of scorpion envenomation., Conclusion: While simultaneous administration of SAV and scorpion venom is effective in preventing scorpion envenomation-related manifestations, delayed administration of SAV, either at standard or elevated dosages, failed to alter any of the scorpion envenomation features.