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.