Use of antithrombin III in inhalation injury

The acute pulmonary inflammatory response to the graded severity of smoke inhalation injury

OBJECTIVES

To determine whether the graded severity of smoke inhalation is reflected by the acute pulmonary inflammatory response to injury.

DESIGN

In a prospective observational study, we assessed the bronchoalveolar lavage fluid for both leukocyte differential and concentration of 28 cytokines, chemokines, and growth factors. Results were then compared to the graded severity of inhalation injury as determined by Abbreviated Injury Score criteria (0, none; 1, mild; 2, moderate; 3, severe; 4, massive).

SETTING

All patients were enrolled at a single tertiary burn center.

PATIENTS

The bronchoalveolar lavage fluid was obtained from 60 patients within 14 hrs of burn injury who underwent bronchoscopy for suspected smoke inhalation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Those who presented with worse grades of inhalation injury had higher plasma levels of carboxyhemoglobin and enhanced airway neutrophilia. Patients with the most severe inhalation injuries also had a greater requirement for tracheostomy, longer time on the ventilator, and a prolonged stay in the intensive care unit. Of the 28 inflammatory mediators assessed in the bronchoalveolar lavage fluid, 21 were at their highest in those with the worst inhalation injury scores (grades 3 and 4), the greatest of which was interleukin-8 (92,940 pg/mL, grade 4). When compared in terms of low inhalation injury (grades 1-2) vs. high inhalation injury (grades 3-4), we found significant differences between groups for interleukin-4, interleukin-6, interleukin-9, interleukin-15, interferon-γ, granulocyte-macrophage colony-stimulating factor, and monocyte chemotactic protein-1 (p < .05 for all).

CONCLUSIONS

These data reveal that the degree of inhalation injury has basic and profound effects on burn patient morbidity, evokes complex changes of multiple alveolar inflammatory proteins, and is a determinant of the pulmonary inflammatory response to smoke inhalation. Accordingly, future investigations should consider inhalation injury to be a graded phenomenon.

Pathophysiology, management and treatment of smoke inhalation injury

Smoke inhalation injury continues to increase morbidity and mortality in burn patients in both the third world and industrialized countries. The lack of uniform criteria for the diagnosis and definition of smoke inhalation injury contributes to the fact that, despite extensive research, mortality rates have changed little in recent decades. The formation of reactive oxygen and nitrogen species, as well as the procoagulant and antifibrinolytic imbalance of alveolar homeostasis, all play a central role in the pathogenesis of smoke inhalation injury. Further hallmarks include massive airway obstruction owing to cast formation, bronchospasm, the increase in bronchial circulation and transvascular fluid flux. Therefore, anticoagulants, antioxidants and bronchodilators, especially when administered as an aerosol, represent the most promising treatment strategies. The purpose of this review article is to provide an overview of the pathophysiological changes, management and treatment options of smoke inhalation injury based on the current literature.