American journal of respiratory and critical care medicine
-
Am. J. Respir. Crit. Care Med. · Jul 1995
Comparative StudyTitration of tidal volume and induced hypercapnia in acute respiratory distress syndrome.
Mechanical ventilation may promote overdistension-induced pulmonary lesions in patients with acute respiratory distress syndrome (ARDS). The static pressure-volume (P-V) curve of the respiratory system can be used to determine the lung volume and corresponding static airway pressure at which lung compliance begins to diminish (the upper inflection point, or UIP). This fall in compliance may indicate overdistension of lung units. ⋯ The end-inspiratory plateau pressure (Pplat) was compared to the UIP, and VT was lowered when the Pplat was above the UIP. In the range of lung volume studied on the P-V curves (up to 1600 ml), a UIP could be shown in only one control patient (at 23 cm H2O). By contrast, a UIP was present on the P-V curve obtained from all patients with ARDS, corresponding to a mean airway pressure of 26 +/- 6 cm H2O, a lung volume of 850 +/- 200 ml above functional residual capacity and 610 +/- 235 ml above PEEP.(ABSTRACT TRUNCATED AT 250 WORDS)
-
Am. J. Respir. Crit. Care Med. · Jul 1995
A dual-binding antibody to E- and L-selectin attenuates sepsis-induced lung injury.
Many studies indicate a pivotal role for neutrophil adhesion in sepsis-associated lung injury. Neutrophil adhesion to endothelium depends on activation and expression of selectin and integrin adhesion receptors. We studied the effects of pretreatment with a dual-binding porcine anti-E- and anti-L-selectin monoclonal antibody (EL-246) on a porcine model of sepsis-induced lung injury. ⋯ There was no significant difference in pulmonary and systemic hemodynamics between Groups 2 and 3. Group 4 animals exhibited a transient neutropenia, but otherwise no other differences in measured parameters were found compared with Group 1 control animals. In conclusion, EL-246 significantly reduced neutrophil accumulation in lung and attenuated sepsis-induced lung injury, but failed to attenuate deranged pulmonary and systemic hemodynamics.(ABSTRACT TRUNCATED AT 250 WORDS)
-
Am. J. Respir. Crit. Care Med. · Jul 1995
Arterial oxygenation time after an FIO2 increase in mechanically ventilated patients.
The time for arterial PO2 to reach equilibrium after a 0.2 increase in the fraction of inspired oxygen (FIO2) was studied, using arterial blood gases measured at 1, 2, 3, 4, 5, 7, 9, and 11 min in 30 stable, mechanically ventilated medical intensive care unit (ICU) patients. Eight patients also underwent a 0.4 increase in FIO2. Each patient's rise in PO2 over time [PO2(t)] was fit to the following exponential equation: PO2(t) = PO2i + (PO2f-PO2i) (1-e-kt), where t refers to time, PO2i and PO2f refer to the initial and final equilibrated PO2. ⋯ The mean t90% (+/- SD) was 6.0 (+/- 3.4) min for all patients (range 1.7 to 14.3 min); 7.1 +/- 2.1 min for 18 patients with chronic obstructive pulmonary disease (COPD) and 4.4 +/- 2.0 min for 12 patients without COPD (p < 0.05). In the subgroup of patients undergoing both an FIO2 increase of 0.2 and 0.4, there was no significant difference in the mean t90%'s for the two FIO2 changes (7.7 versus 7.7 min). We conclude that after a 0.2 or 0.4 increase of FIO3, a 15-min equilibration time period is adequate for 90% of the increase in PO2 to occur, in stable, mechanically ventilated medical ICU patients.
-
Am. J. Respir. Crit. Care Med. · Jul 1995
Transmission of multidrug-resistant tuberculosis in a large urban setting.
Multidrug resistance has become an increasingly important problem in the control and prevention of tuberculosis in large urban centers. Although several small outbreaks of multidrug-resistant (MDR) tuberculosis in New York City have been reported, the increase in the number of cases is not fully explained by these recognized outbreaks, and the modes of transmission have not been clearly delineated. Transmission patterns of MDR tuberculosis in New York City, therefore, were studied by stratifying Mycobacterium tuberculosis isolates from 167 newly diagnosed tuberculosis patients according to their DNA restriction fragment length polymorphisms (RFLP). ⋯ S.-born (57%; p < 0.001), and have MDR tuberculosis (79%; p < 0.0005). In a logistic regression model, primary tuberculosis remained significantly associated with MDR tuberculosis and black race. In contrast to previous reports, in New York City recent exogenous transmission accounts for most new cases of multidrug-resistant tuberculosis.