Core-peripheral temperature gradient as a diagnostic test in dyspnoea.

OBJECTIVES To evaluate whether the core-peripheral temperature gradient could be used to distinguish between cardiac and respiratory causes of dyspnoea. METHODS In total, 50 patients were enrolled in the study, based on the following inclusion criteria: (a) a primary presenting complaint of dyspnoea; (b) age > 40 years; (c) respiratory rate > 20 breaths/min; (d) hypoxia. The tympanic temperature and the temperature of the nasal tip were recorded, and the patient's discharge data and chest x ray results checked. Where there was discordance, arbitration was carried out by another researcher. RESULTS Four patients were excluded, hence the final study sample was 46 patients. There was a statistically significant difference between the mean temperature gradients of the two study populations (p < 0.001). A gradient of > 8 degrees C was able to rule in a cardiovascular cause (92% specificity) whereas one of < 5 degrees C could rule it out (100% sensitivity). CONCLUSION The test is safe, non-invasive and inexpensive. Although there were some limitations to the study, the test can still be commended as a useful adjunct to the emergency assessment of the acutely breathless patient.