Circadian variation of cardiogenic pulmonary oedema

• Prehospital occurrence of cardiogenic pulmonary oedema reflects significant circadian variation.
• The peak incidence occurs in the ninth hour in the morning.
• Patients with hypertension and pulmonary oedema present with different pattern of variation than hypotensive.

IntroductionCircadian variation of in-hospital acute cardiogenic pulmonary oedema (CPE) with the highest occurrence in the early morning has been reported repeatedly. However, no study evaluating circadian variation of CPE in the field has been published. Therefore, we decided to evaluate the circadian variation of CPE in the Central Bohemian Region of the Czech Republic in the patients treated by regional emergency medical service (EMS) and analyse its association with baseline blood pressure in the field.MethodsWe extracted all dispatches to CPE cases from EMS database for the period from 1.11.2008 to 30.6.2014 and analysed for circadian variation. We identified the patients presenting with CPE coupled with arterial hypertension (systolic blood pressure > 140 mm Hg) and hypotension (systolic blood pressure < 90 mm Hg) and compared the subgroups (both subgroups include 2744 subjects).ResultsIn 4747 episodes of CPE, maximal occurrence was detected in the ninth hour in the morning, representing 7.7% of all CPE episodes (p < 0.05). While CPE with hypertension (2463 subjects) reached maximal occurrence also in the ninth hour (7.4% of all cases, p < 0.05), CPE with hypotension (281 patients) was most frequent in the fourteenth hour (8.6% of all cases, p < 0.05).ConclusionThe highest occurrence of CPE was observed in the ninth hour in the morning in our study. Moreover, differences in circadian variation between CPE with hypertension and hypotension were identified. Knowledge of these patterns may have an impact on the logistic of prehospital emergency care and on preventive measures in the patients who have previously undergone CPE.