Professor of Emergency Medicine
Chief, Hyperbaric Medicine

Research Interests

Pathophysiology of CO poisoning and the mechanism for benefit of hyperbaric oxygen therapy. High pressure inert gas-oxygen interactions, and endothelial cell - leukocyte interactions triggered by decompression stress.

Research Techniques

In vitro models of lipid peroxidation, analysis of products of lipid peroxidation, polymorphonuclear leukocyte (PMN) function studies, tissue enzyme assays, oxidant production by endothelial cells in culture, rat exposures to CO, O2, and smoke, invasive cardiovascular monitoring, high gas pressure studies of free radical generating systems, clinical studies.

Summary of Research Program

Carbon monoxide is the leading cause of death by poisoning in the U.S. and survivors are at risk for developing a variety of complications. Hyperbaric oxygen appears to reduce mortality and morbidity. Our attempts to broaden the knowledge base regarding these issues include biochemical, physiological, and clinical studies. Laboratory studies are directed toward an elucidation of the mechanism for CO mediated vascular insult and oxidative injury using rat models. Biochemical studies are being done to determine the mechanism for benefit of hyperbaric oxygen in this model and in the clinical setting. A clinical study is also underway to evaluate plasma markers that may predict CO-associated neurological sequelae.
Additional studies are investigating the mechanism of CO injury to the vascular endothelium. This work is aimed to elucidate the pathophysiology of perivascular oxidative injury caused by environmental CO contamination.

Key References

Thom, S.R., Taber, R.L., Mendiguren, I.I., Clark, J.M., Hardy, K.R. and Fisher, A.B. Delayed neuropsychological sequelae following carbon monoxide poisoning and its prophylaxis by treatment with hyperbaric oxygen. Ann. Emerg. Med. 25:474-480, 1995.

Thom, S.R., Yu, Y.A., and Ischiropoulos, H. Vascular endothelial cells generate peroxynitrate in response to carbon monoxide exposure. Chem. Res in Toxicol. 10:1023-1031, 1997.

Thom, S.R., Ohnishu, S.T., Fisher, D., Xu, Y.A., and Ischiropoulos, H. Pulmonary vascular stress from carbon monoxide. Toxicol. Appl. Pharmacol. 154:12-19, 1999.

Thom, S.R., Fisher, D., Xu, Y.A., Garner, S., and Ischiropolous, H. Role of nitric oxide derived oxidants in vascular injury from carbon monoxide in the rat. Am. J. Phys. 276 (Heart Vasc. Physiol.) H984-992, 1999.