American journal of respiratory and critical care medicine
-
Am. J. Respir. Crit. Care Med. · Jun 1997
Effects of inhaled nitric oxide or inhibition of endogenous nitric oxide formation on hyperoxic lung injury.
Nitric oxide (NO) may either protect against or contribute to oxidant-induced lung injury. In this study, we sought to determine whether either inhaled NO in concentration of 10 and 100 parts per million (ppm) or inhibition of endogenous NO formation with L-NG nitroarginine methyl ester (L-NAME) or aminoguanidine alters the extent of lung injury in rats breathing 100% O2. Lung thiobarbituric acid reactive substances (TBARS), wet to dry lung weight ratio (Q(W)/Q(D)), vascular and epithelial permeability (assessed by simultaneous intravenous administration of 131I-labeled albumin and intraalveolar instillation of 125I-labeled albumin), alveolar liquid clearance (evaluated based on the increase in alveolar protein concentration), and lung liquid clearance (gravimetric method) were determined after 40 h exposure to either 100% or 21% O2. ⋯ L-NAME, but not aminoguanidine, increased lung TBARs. These results suggest that, depending on its concentration, inhaled NO can either reduce or increase the early consequences of hyperoxic lung injury. Treatment with L-NAME, and to a lesser extent aminoguanidine, worsened hyperoxic lung injury, indicating a protective effect of endogenous NO.
-
Am. J. Respir. Crit. Care Med. · Jun 1997
Clinical TrialYield of computed tomography and bronchoscopy for the diagnosis of Mycobacterium avium complex pulmonary disease.
Mycobacterium avium complex (MAC) pulmonary disease with nodules and bronchiectasis is increasing. But the usefulness of computed tomography (CT) and bronchoscopy for diagnosis and the significance of MAC isolation from respiratory secretions are still unclear. For a 4-yr period, we prospectively examined the role of bronchoscopy with bronchial washing and transbronchial lung biopsy in 26 patients who had clusters of small nodules in the periphery of the lung associated with ectatic changes of the draining bronchi on the CT scan. ⋯ Seven of the eight biopsy-positive patients received treatment and responded by sputum conversion and/or radiographic improvement. We found that the CT finding was a useful clue to suspect MAC pulmonary disease and that the bronchial washing was more sensitive than the routine expectorated sputum for MAC isolation. Demonstration of granuloma in more than half of the MAC-positive patients would suggest that MAC may have invaded the lung tissue rather than colonized in the airways.
-
Am. J. Respir. Crit. Care Med. · May 1997
Does transfusion practice affect mortality in critically ill patients? Transfusion Requirements in Critical Care (TRICC) Investigators and the Canadian Critical Care Trials Group.
In 4,470 critically ill patients, we examined the impact of transfusion practice on mortality rates. As compared with survivors, patients who died in intensive care units (ICU) had lower hemoglobin values (95 +/- 26 versus 104 +/- 23 g/L, p < 0.0001) and were transfused red cells more frequently (42.6% versus 28.0%, p < 0.0001). In patients with cardiac disease, there was a trend toward an increased mortality when hemoglobin values were < 95 g/L (55% versus 42%, p = 0.09) as compared with anemic patients with other diagnoses. ⋯ In the subgroup with cardiac disease, increasing hemoglobin values in anemic patients was associated with improved survival (OR = 0.80 for each 10 g/L increase, p = 0.012). We conclude that anemia increases the risk of death in critically ill patients with cardiac disease. Blood transfusions appear to decrease this risk.
-
Am. J. Respir. Crit. Care Med. · May 1997
Randomized Controlled Trial Clinical TrialProtective effect of intravenously administered cefuroxime against nosocomial pneumonia in patients with structural coma.
In comatose patients admitted to an ICU, particularly those with head injury, the incidence of early onset pneumonia is exceedingly high. We performed an open, prospective, randomized, and controlled clinical trial aiming at the reduction of the incidence of ventilator-associated pneumonia in head-injured patients and patients with stroke requiring mechanical ventilation. One hundred patients were included because of head injury or coma caused by medical stroke and with Glasgow coma scores < or = 12 and mechanical ventilation > 72 h. ⋯ No differences were found with regard to mortality and morbidity when comparing the study population with the control group. Nevertheless, when comparing patients with pneumonia (from both study and control groups) with those without it, there was a decrease in total hospital stay (35 +/- 13 versus 25 +/- 14 d, p = 0.048) and ICU stay (20 +/- 11 versus 11 +/- 7 d, p = 0.001). The study demonstrated that the administration of two single high doses 1,500 mg each of cefuroxime after the intubation of patients comatose because of head injury or medical stroke is an effective prophylactic strategy to decrease the incidence of ventilator-associated pneumonia.
-
Am. J. Respir. Crit. Care Med. · May 1997
Randomized Controlled Trial Clinical TrialInverse ratio ventilation (I/E = 2/1) in acute respiratory distress syndrome: a six-hour controlled study.
To assess the cardiorespiratory effects of a prolonged application of inverse ratio ventilation (IRV), we compared IRV (I/E = 2) with conventional ventilation (CV) (I/E = 0.5), applied for 6 h each in a randomized order, with constant tidal volume (VT) and total positive end-expiratory pressure (PEEP(tot)) in eight patients with acute respiratory distress syndrome (ARDS). After 1 h, IRV resulted in a lower peak inspiratory pressure (PIP) (28.2 +/- 1.5 versus 35.6 +/- 1.7 cm H2O, p < 0.05), an unchanged plateau pressure, and a higher mean airway pressure (MAP) (17.8 +/- 0.8 versus 15.6 +/- 0.5 cm H2O, p < 0.05) than CV. No significant difference in Pa(O2) and shunt fraction (QS/QT) was observed (83 +/- 7 mm Hg and 40 +/- 4% in CV versus 92 +/- 14 mm Hg and 35 +/- 3% in IRV, respectively). ⋯ Cardiac index (CI) and oxygen delivery (D(O2)) were lower in IRV (3.7 +/- 0.4 L/min/m2 and 500 +/- 61 ml/min/m2 versus 4.6 +/- 0.5 L/min/m2 and 617 +/- 80 ml/min/m2, respectively, p = 0.05 for both). Regardless of the considered parameter, no significant difference was observed between results after 1, 2, 4, and 6 h in each mode. We conclude that IRV at a ratio that results in a significant intrinsic PEEP does not improve Pa(O2), enhances CO2 elimination, decreases cardiac output (CO), and does not exert any time-dependent effect.