Pressure-controlled ventilation attenuates lung microvascular injury in a rat model of activated charcoal aspiration.
BACKGROUND
Previous animal data suggest that aspiration of activated charcoal is associated with pulmonary microvascular injury that may be related to excessive ventilator-induced airway pressures. The purpose of this study was to test the hypothesis that ventilator-induced airway trauma contributes to the lung vascular injury observed following activated charcoal aspiration.


METHODS
Capillary filtration coefficient (Kf,c), a sensitive measure of lung microvascular permeability, was determined isogravimetrically prior to and after intratracheal instillation of 0.4 ml/kg (12% weight/vol. solution, pH 7.4) activated charcoal oran equal volume of sterile water in isolated, perfused rat lungs in which ventilation was either pressure-controlled at 10cm H2O or volume-controlled at 5 ml/kg.


RESULTS
There was significant lung injury in both activated charcoal groups regardless of ventilation method compared to control lungs or lungs administered sterile water (p < 0.05 ANOVA). However, injury to pressure-controlled ventilated lungs was significantly less than lungs ventilated with traditional, volume-controlled ventilation.


CONCLUSIONS
The results of this investigation demonstrate that pressure-controlled ventilation reduces the lung microvascular injury observed following aspiration of activated charcoal as compared to traditional volume-controlled ventilation methods.
Arnold
Thomas C
TC
Department of Emergency Medicine, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130, USA. TArnol@lsuhsc.edu
Zhang
Shu
S
Xiao
Feng
F
Conrad
Steven A
SA
Carden
Donna L
DL
D000280:Administration, Inhalation; D000818:Animals; D002196:Capillaries / Q000473:pathology; D002199:Capillary Permeability / Q000187:drug effects; D002606:Charcoal / Q000008:administration & dosage / Q000506:poisoning*; D008170:Lung Compliance / Q000187:drug effects; D008171:Lung Diseases / Q000139:chemically induced / Q000473:pathology* / Q000628:therapy*; D008297:Male; D011669:Pulmonary Wedge Pressure; D051381:Rats; D017207:Rats, Sprague-Dawley; D012121:Respiration, Artificial; D013990:Tidal Volume
D002606:Charcoal