Lung thermography during the initial reperfusion period to assess pulmonary function in cellular ex vivo lung...

Thermography is a noninvasive technology to detect low temperatures in poorly circulated areas. In ex vivo lung perfusion (EVLP), lungs are rewarmed to body temperature during the initial 1 h. Currently, the effect of graft thermal changes during the rewarming phase on pulmonary function is unknown. In this study, we evaluated the correlation of lung surface temperature with physiological parameters, wet/dry ratio, and transplant suitability in Lund-type EVLP.

Fifteen pigs were divided into three groups: control group (no warm ischemia) or donation after circulatory death groups with 60 or 90 min of warm ischemia (n = 5, each). Thermal images of the lower lobes were continuously collected from the bottom of an organ chamber using infrared thermography throughout EVLP.

At 8 min, lung surface temperatures of nonsuitable cases were significantly lower than in suitable cases (25.1 ± 0.6 vs. 27.8 ± 1.2°C, p < 0.001), while there was no difference in lung surface temperatures between the two groups at 0-4 min and 12-120 min. There was a significant negative correlation between lung surface temperatures at 8 min and wet/dry ratio at 2 h in the lower lobes (R = -0.769, p < 0.001, cutoff = 26°C, area under the curve = 1.0). A lung surface temperature of <26°C was significantly correlated with poor pulmonary function and transplant nonsuitability.

A lung surface temperature of ≥26°C at 8 min is a good early predictor of transplant suitability in cellular EVLP and might be applicable in clinical EVLP.