American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · May 1995
Do lower respiratory tract infections in early childhood cause chronic obstructive pulmonary disease?
The hypothesis that lower respiratory tract infections (LRTI) in early childhood lead to chronic obstructive pulmonary disease (COPD) in late adult life has been difficult to test. However, a unique opportunity arose when records were discovered in the counties of Hertfordshire and Derbyshire, England, that contained information about childhood LRTI recorded 60 to 70 years ago. The lung function of some men still living in these counties was examined. ⋯ In Derbyshire men, pneumonia before 2 yr of age was associated with a large and highly significant reduction in mean FEV1, adjusted for age and height. These findings were independent of smoking and social class. These data support a causal relationship between LRTI in early life and subsequent COPD.
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Am. J. Respir. Crit. Care Med. · May 1995
Clinical Trial Controlled Clinical TrialEffect of inhaled nitric oxide on right ventricular function in adult respiratory distress syndrome.
To determine whether inhaled nitric oxide (NO) affects pulmonary circulation, thereby improving right ventricular (RV) function in adult respiratory distress syndrome (ARDS), we studied 13 patients with both a lung injury severity score of 2.5 or more and a mean pulmonary artery pressure higher than 30 mm Hg. RV function was assessed by a thermodilution technique using a pulmonary artery catheter equipped with a rapid response thermistor before and 15 min after initiation of inhalation of NO (5 ppm). ⋯ The resulting fall in pulmonary vascular resistance (211 +/- 43 versus 180 +/- 59 dyn-s/cm5, p < 0.05) was associated with an increase in RV, ejection fractions (32 +/- 5 versus 36 +/- 6%, p < 0.05), a trend toward decreased RV end-systolic (96 +/- 25 versus 85 +/- 19 ml/m2, NS) and end-diastolic (142 +/- 36 versus 131 +/- 27 ml/m2, NS) volumes, and a decrease in right atrial pressures (10.9 +/- 2.9 versus 9.6 +/- 3.2 mm Hg, p < 0.05). No relationship was seen between the improvement in arterial oxygenation and the decrease in pulmonary vascular resistance.(ABSTRACT TRUNCATED AT 250 WORDS)
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Am. J. Respir. Crit. Care Med. · Apr 1995
Randomized Controlled Trial Clinical TrialCO2 rebreathing during BiPAP ventilatory assistance.
BiPAP ventilatory assistance can increase minute ventilation and reduce respiratory effort, but does not always reduce PaCO2. We studied the effects of BiPAP ventilatory assistance on PaCO2 and examined specific mechanisms whereby BiPAP ventilatory assistance may not lower PaCO2. BiPAP ventilatory assistance using a non-rebreather valve and volume cycled ventilation at similar settings produced significantly lower PaCO2 than BiPAP ventilatory assistance using a standard exhalation device. ⋯ Changing exhalation devices had no significant effect on BiPAP pressure generation or sensing capabilities. Our results indicate that the use of a standard exhalation device during BiPAP ventilatory assistance causes CO2 rebreathing, which can blunt any effect of BiPAP on PaCO2. Use of an appropriate alternative exhalation device can eliminate this problem.