Effect of reduced bronchial circulation on lung fluid flux after smoke inhalation in sheep

Abstract

We determined the effect of reduced bronchial blood flow on lung fluid flux through changes in lung lymph flow, lung wet weight-to-dry weight (wet/dry) ratios, and pulmonary microvascular reflection coefficient (sigma). In the first of two surgical procedures, Merino ewes (n = 21) were surgically prepared for chronic study. Five to seven days later, in a second operation, the bronchial artery of the injection group (n = 7) was ligated, and 4 ml of 70% ethanol were injected into the bronchial artery to cause sclerosis of the airway circulation. In the ligation group (n = 7), only the bronchial artery was ligated. In the sham group (n = 7), the bronchial artery was surgically exposed but left intact without ligation or ethanol injection. One day after these operations the animals received a tracheotomy and 48 breaths of cotton smoke. The value of sigma was determined at two points: 24 h before the second surgical procedure and 24 h after smoke inhalation. Lung lymph flow, blood-gas parameters, and hemodynamic data were measured every 4 h after injury. At the end of investigation, samples of lung were taken for determination of blood-free wet/dry ratio. In the sham group, inhalation injury induced a gradual increase in pulmonary vascular resistance and lung lymph flow, which was associated with deterioration of oxygenation. Reduction of the bronchial blood flow attenuated these pathophysiological changes, and the degree of this attenuation was greater in the injection group than in the ligation group. The value of sigma was significantly higher after smoke inhalation in the injection group compared with the sham group (0.77 +/- 0.04 vs. 0.61 +/- 0.03, means +/- SE) at 24 h. The mean wet/dry ratio value of the injection group animals was 30% less than that of the sham group. Our data show that the bronchial circulation contributes to edema formation in the lung occurring after acute lung injury with smoke inhalation.

Inhibition of lung permeability changes after burn and smoke inhalation by an anti-interleukin-8 antibody in sheep

“…*Signifi cant difference (P < 0.05) from baseline values delayed in onset. 10,13,20 In contrast to the inability of K2.2 to reduce burned tissue permeability, it signifi cantly attenuated lung permeability changes in the present study. These fi ndings are in accordance with those of a previous report suggesting the benefi cial effect of the anti IL-8 antibody on smoke inhalation.…”

“…The details of the smoking procedure and the chemical composition of the smoke have been described previously. 13 After smoke insuffl ation, another 20% BSA third-degree burn was infl icted on the fl ank of the other side. A Foley catheter was placed in the bladder to measure urine output.…”

“…These respiratory settings allowed for the rapid disappearance of carboxyhemoglobin (COHb) after smoke inhalation. 13 For fl uid resuscitation, Ringer's lactate solution was given according to the Parkland formula 14 (4 ml/% burned surface area/kg body weight for the fi rst 24 h and 2 ml/% burned surface area/kg body weight/day for the next 48 h). One half of the volume for the fi rst day was infused in the initial 8 h and the rest was infused over the next 16 h. Urine was collected and recorded every 24 h. Fluid balance was calculated by the total fl uid volume infused subtracted by the urine output every 24 h, expressed as ml/kg per day.…”

Ketorolac attenuates cardiopulmonary derangements in sheep with combined burn and smoke inhalation injury

“…There is a marked increase (> 20-fold) in airway blood flow after smoke inhalation injury [21]. In the present study, we also noted this airway hyperaemia, which confirmed the findings of a previous report from our laboratory [3].…”

Airway Blood Flow Changes and Airway Obstruction Following Lung Injury

“…This has led to clinical use of nebulized heparin in the treatment of burned patients with inhalation injury (Desai et al, 1998). In addition, considering that this airway injury might play an important role in the parenchymal damage, we determined the role of the bronchial circulation in the pulmonary injury (Abdi et al, 1991;Sakurai et al, 1998). We discovered that limiting the bronchial circulation markedly reduced the parenchymal damage seen with smoke inhalation.…”