Flammability of Ocular Surface Lubricants

Abstract

Purpose: Surgical fires pose a substantial risk to patients and can cause significant injury, especially in oculofacial surgery. Ocular surface lubricants can potentially act as fuel for an operating room fire. We present an experimental analysis of the flammability of 9 commonly used ophthalmic lubricants under 4 ignition sources used in oculofacial surgery with and without supplemental oxygen. Methods: The flammability of 9 ophthalmic lubricants were tested under various operating room conditions. Each lubricant was exposed to 4 different ignition sources: an open flame lighter, monopolar cautery, bipolar cautery, and hand-held high temperature cautery, and the response of the lubricant was recorded. The testing was conducted both in room air and with 6 L/minute of 100% oxygen directed at the lubricant through a nasal cannula. Any reaction in which there was ignition, sparking, smoking, or a transient or permanent change in appearance of the lubricant was deemed notable. Results: Of the 9 lubricants tested, 4 displayed a reaction to the ignition source. Without supplemental oxygen, 100% petrolatum and neomycin-polysporin-bacitracin-hydrocortisone ointment produced some smoke when applied with the high temperature cautery. Notably, under both the conditions of no supplemental oxygen and with the addition of 6 L/minute of 100% oxygen, the carboxymethylcellulose drops and lidocaine jelly both conducted and sparked with the monopolar cautery leaving visible burn marks on the paper. Conclusions: The overall fire hazard posed by ocular surface lubricants is low. Some topical lubricants can conduct electricity from monopolar cautery, which could increase the risk of inadvertent electrical burns. Certain lubricants could potentially become a fuel source when used in combination with hand-held high temperature battery cautery. Bipolar cautery was not associated with either increased conductivity or flammability with any of the lubricants tested.