American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Aug 2000
Comparative StudyLung function reference values in Chinese children and adolescents in Hong Kong. I. Spirometric values and comparison with other populations.
As part of a comprehensive evaluation of lung function in Hong Kong-born Chinese children and adolescents, this study was conducted to determine updated prediction equations for spirometry, to evaluate the secular changes of lung function during the past decade, and to compare these results with other data sets. The results are based on 852 (392 male, 460 female) healthy students, age 7 to 19 yr, recruited from seven schools in Hong Kong. All were born and lived in Hong Kong, nonsmokers, free from past or present symptoms or diseases affecting the respiratory tract. ⋯ FEV(1) values showed a similar pattern with lesser difference between the two ethnic groups. Compared with recent data from Chinese children in Singapore, a similar pattern with overall lesser difference of the two populations was present in boys, whereas there was no significant difference between girls in the two places. Our findings support the conclusion that exogenous factors may contribute significantly to the differences in lung function values among ethnic groups and that it is important to examine normative values of various populations for secular trends.
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Am. J. Respir. Crit. Care Med. · Aug 2000
CC chemokines and interleukin-5 in bronchial lavage fluid from patients with status asthmaticus. Potential implication in eosinophil recruitment.
In status asthmaticus (SA), severe bronchial inflammation is associated with acute respiratory failure. Neutrophils are the prominent cells found in bronchi from SA patients, but eosinophils are also recruited within the first 48 h after the beginning of mechanical ventilation (MV). Interleukin (IL)-5 and CC chemokines have been directly implicated in the pathophysiology of allergic asthma. ⋯ Eosinophil chemotactic activity in BLF was increased in asthmatic subjects (A and SA groups) as compared with the other groups, and in SA patients as compared with A patients. Addition of neutralizing anti-IL-5, anti-MCP-3, anti-eotaxin, and anti-RANTES antibodies significantly inhibited the eosinophil chemotactic activity as compared with that of native BLF. This study shows that the levels of various CC chemokines and IL-5 are increased in airways of SA patients, and are potentially involved in eosinophil recruitment.
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Am. J. Respir. Crit. Care Med. · Aug 2000
Reverse-thrust ventilation in hypercapnic patients with acute respiratory distress syndrome. Acute physiological effects.
Techniques of tracheal gas insufflation (TGI) have been shown to enhance CO(2) clearance efficiency in mechanically ventilated patients with acute respiratory distress syndrome (ARDS). Clinical studies have explored the effects of such techniques only at moderate intratracheal gas flow rates, with TGI superimposed to mechanical ventilation in a continuous fashion, or synchronized to the expiratory phase of the duty cycle. We examined the effects of intratracheal pulmonary ventilation (ITPV), delivering the entire tidal volume (VT) in the proximity of the tracheal carina, with all the gas flow supplied continuously through a reverse-thrust catheter (RTC). ⋯ During transition from mechanical ventilation to ITPV, tracheal positive end-expiratory pressure (PEEP(tr)) decreased with a correspondent decrease in EELV. Both were restored by increasing the PEEP at the ventilator by 3.6 +/- 2.0 cm H(2)O. These data suggest that in patients with ARDS ITPV effectively reduces dead space ventilation and the employment of the RTC may limit or avoid dynamic hyperinflation.
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Am. J. Respir. Crit. Care Med. · Aug 2000
Comparative StudyPartial liquid ventilation ventilates better than gas ventilation.
Partial liquid ventilation (PLV) improves oxygenation in several models of lung injury. However, PLV has only been compared with conventional gas ventilation (GV) with low PEEP. Both PLV and GV can markedly improve oxygenation when PEEP is set above the lower corner pressure (Plc) on the inspiratory pressure-volume (P-V) curve of the total respiratory system. ⋯ Mean arterial blood pressure, mean pulmonary artery pressure, pulmonary artery occlusion pressure, and central venous pressure, increased and SVR decreased in GV (p < 0.05). The extent and the severity of lung injury in the dependent regions was greater in the GV group (p < 0.05). Both PLV and GV improved oxygenation, but PLV resulted in better ventilation than GV while preserving lung structure when PEEP was set 1 cm H(2)O above the Plc and PIP limited to 35 cm H(2)O.
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Am. J. Respir. Crit. Care Med. · Aug 2000
Long-term follow-up of hexamethylene diisocyanate-, diphenylmethane diisocyanate-, and toluene diisocyanate-induced asthma.
In 1976-1992 245 new cases of asthma induced by diisocyanates were diagnosed, caused by hexamethylene diisocyanate (HDI) in 39%, diphenylmethane diisocyanate (MDI) in 39%, and toluene diisocyanate (TDI) in 17% of the cases. Our aim was to study the clinical outcome of diisocyanate-induced asthma. A questionnaire was sent to the 235 patients alive in 1995, and validated by reexamining clinically 91 of them. ⋯ Patients with HDI-induced asthma used less medication (OR 0.412; CI 0.229, 0.739) than patients with MDI- and TDI-induced asthma. The results confirm the generally rather poor medical outcome of diisocyanate-induced asthma; the persistence of symptoms and unspecific bronchial reactivity were pronounced in TDI-induced asthma. A more favourable outcome was associated with IgE mediation and HDI inducement.