American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Mar 1995
Comparative StudyCardiorespiratory effects of volume- and pressure-controlled ventilation at various I/E ratios in an acute lung injury model.
Numerous approaches to the provision of mechanical ventilation during acute lung injury are currently available. Of these, pressure control inverse ratio ventilation has been considered superior to volume control ventilation with PEEP with respect to improving gas exchange and minimizing cardiovascular compromise. However, no study systematically compares volume-controlled (VC) and pressure-controlled (PC) ventilation while maintaining mean airway pressure (MAP) constant at varying I/E ratios. ⋯ MAP was kept constant throughout the study at 25 +/- 2 cm H2O while ventilating all animals with a VT of 10 ml/kg and a rate of 20/min by randomized application of VC and PC with I/E ratios of 1:2, 2:1, and 4:1. Despite liberal fluid administration, all ventilatory modes depressed cardiac output compared with preinjury values. However, gas exchange and hemodynamics did not differ among ventilation modes or I/E ratios.(ABSTRACT TRUNCATED AT 250 WORDS)
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Am. J. Respir. Crit. Care Med. · Mar 1995
Effect of synchronized, systolic, lower body, positive pressure on hemodynamics in human septic shock. A pilot study.
The pathophysiologic disturbance observed in volume-resuscitated patients with septic shock is primarily that of hyperdynamic circulation with a markedly reduced systemic vascular resistance. We hypothesized that external, mechanically applied, phasic lower body positive pressure could increase systemic vascular resistance and, thus, blood pressure in patients with refractory septic shock. A total of nine studies were performed on seven patients with septic shock refractory to volume resuscitation and vasopressors. ⋯ Heart rate, central venous pressure, pulmonary capillary wedge pressure, arterial pH, arterial pO2, and mixed venous pO2 were unchanged. Synchronized external systolic compression of the lower extremities increased mean arterial pressure and cardiac output in seven patients with refractory septic shock. This hemodynamic improvement was independent of changes in calculated systemic vascular resistance.
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Am. J. Respir. Crit. Care Med. · Mar 1995
Lower airways inflammation during rhinovirus colds in normal and in asthmatic subjects.
Human rhinoviruses (HRV) cause the majority of common colds and are etiologically linked with changes in lower airways physiology and asthma exacerbations. We hypothesized that changes in bronchial mucosal inflammatory cell populations may be responsible for HRV-induced changes in airway reactivity. We examined bronchial mucosal biopsies during experimental infections with HRV serotype 16 and measured changes in histamine reactivity. ⋯ There was an increase in epithelial eosinophils with the cold (p = 0.042), and in asthmatics this appeared to persist into convalescence. A peripheral blood lymphopenia correlated with increased responsiveness (r = 0.062, p = 0.014). Rhinoviral colds are associated with a bronchial mucosal lymphocytic and eosinophilic infiltrate that may be related to changes in airway responsiveness and asthma exacerbations.
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Am. J. Respir. Crit. Care Med. · Mar 1995
Case ReportsRecurrence of diffuse panbronchiolitis after lung transplantation.
Diffuse panbronchiolitis (DBP) is characterized by chronic inflammation of the upper and lower respiratory tract. DPB has been found almost exclusively in oriental populations. We describe the occurrence of a case of DPB in an African American patient who underwent bilateral sequential lung transplantation. ⋯ Allograft function improved within a few weeks after beginning treatment with erythromycin. This early recurrence is suggestive of a systemic etiology of DPB. Although recurrence of other systemic diseases has been reported after lung transplantation, no previous patients have been reported with early functional deterioration based solely on disease recurrence.
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Am. J. Respir. Crit. Care Med. · Feb 1995
Clinical risks for development of the acute respiratory distress syndrome.
To further understanding of the epidemiology of acute respiratory distress syndrome (ARDS), we prospectively identified 695 patients admitted to our intensive care units from 1983 through 1985 meeting criteria for seven clinical risks, and followed them for development of ARDS and eventual outcome. ARDS occurred in 179 of the 695 patients (26%). The highest incidence of ARDS occurred in patients with sepsis syndrome (75 of 176; 43%) and those with multiple emergency transfusions (> or = 15 units in 24 h) (46 of 115; 40%). ⋯ Mortality was threefold higher when ARDS was present (62%) than among patients with clinical risks who did not develop ARDS (19%; p < 0.05). The difference in mortality if ARDS developed was particularly striking in patients with trauma (56% versus 13%), but less in those with sepsis (69% versus 49%). The mortality data should be interpreted with caution, since the fatality rate in ARDS patients appears to have decreased in our institution from the time that these data were collected.(ABSTRACT TRUNCATED AT 250 WORDS)