Thermal softening of tracheal tubes: an unrecognized hazard of the Bair Hugger active patient warming system

Abstract

The Bair Hugger system is a new and highly effective active patient warming system which produces a layer of warm air between the patient and the warming system. We report an instance of marked softening and distortion of a polyvinyl chloride tracheal tube caused by this layer. We also present laboratory data indicating that this is a likely problem under routine theatre conditions, with suggestions for prevention.

Broken nasotracheal tube aspiration in a horse during anaesthetic recovery

“…; Southwood and Gaynor ; Taylor and Clarke ; Wagner ; Bednarski ). In human medicine, nasotracheal tubes are warmed prior to insertion to make them more flexible, but this may lead to tubes kinking more easily (Ayala and Coe ; Thong and Wong ). While it is possible that our tube had been warmed by the patient's body heat, it is still unexpected that this would have a significant impact on its rigidity.…”

“…Despite this, because of the increased wall thickness and rigidity of the large animal tubes, breakage due to flexion alone seems unlikely, leading many authors to recommend an ETT left in situ for recovery (Thomas et al 1987;Southwood and Gaynor 2003;Taylor and Clarke 2007;Wagner 2008;Bednarski 2009). In human medicine, nasotracheal tubes are warmed prior to insertion to make them more flexible, but this may lead to tubes kinking more easily (Ayala and Coe 1997;Thong and Wong 2011). While it is possible that our tube had been warmed by the patient's body heat, it is still unexpected that this would have a significant impact on its rigidity.…”

A simple solution to unexpected kinking of endotracheal tube

“…[910] We feel that use of Bair Hugger set at 40°C might have contributed to its softening and tendency to repeated kinking.…”

External reinforcement for extraoral kinking of tracheal tube during pediatric anesthesia

“…If the TT's temperature increases to 36°C, the tube softens making it liable to kinking (1). Bair Hugger patient warming blanket has been implicated in this (2).…”