Comparison of efficacy aerosolized and oral Vit. E therapy in sheep subjected to burn and smoke inhalation

Abstract

Introduction. α-Tocopherol (Vit. E) plays a pivotal role in clinical settings associated with oxidative stress. In patients suffering from burn and smoke inhalation injury, a decrease in Vit. E plasma level is typically linked with increased mortality rates. Previously we have shown that oral administration of α-tocopherol ameliorates the acute lung injury in sheep with burn and smoke inhalation injury. However, thermal injury often associates with ileus. In the present study we tested the effect of aerosolized Vit. E nebulized into the airway. Method. Sixteen adult ewes, weighing ∼33 kg, were operatively instrumented for chronic study. The sheep were randomly allocated to groups (a) noninjured, nontreated, (b) injured, nontreated, (c) injured, nebulized with Vit. E, and (d) injured, orally administered with Vit. E. The sheep were subjected to a third-degree flame burn (40% of total body surface) and smoke inhalation (cotton smoke). All groups were placed on the ventilator and resuscitated similarly. Results. Pulmonary dysfunction in injured nontreated group was associated with significant depletion of both α- and γ-tocopherol. Compared with injured controls, the Vit. E nebulization group had lung tissue Vit. E levels which were significantly increased (∗ P < 0.05). There was also an improved PaO 2/FiO 2 ratio at 48 h postinjury (Control, 93 ± 15.9; Oral Vit. E, 232 ± 31.8; Nebulized, 305 ± 30.9), and pulmonary microvascular permeability index (Control, 27.53 ± 10.29; Oral Vit. E 14.30 ± 4.85; Nebulized, 8.68 ± 2.218) in these animals. Conclusions. The role of Vit. E on pulmonary antioxidant defense system has been known. Previously there was no effective technique to administer Vit. E directly into the injured organ. We think that aerosolized Vit. E nebulization will be a good treatment strategy for patients with smoke inhalation and burn.