Atmospheric pressure changes and outdoor temperature changes in relation to spontaneous pneumothorax

Study aims: To examine the influence of atmospheric pressure (AP) and tempe rature changes on the incidence of idiopathic spontaneous pneumothorax (SP) , Methods: From December 1991 through November 1993, 115 consecutive SP cases were selected. Patients were included after being in Amsterdam at least 1 full da, before contracting the SP, Differences in air temperature and AP (provided hourly by the national weather bureau) for the days of the SP occurrence and the d ays previous to it were recorded to measure influences of air temperature a nd AP, The correlation between days with lightning and SP and clustering of SP was evaluated. Results: SP occurred on 14.7% of the days in the 2-year period. There was n o relationship between SP and a rise or fall in AP (Poisson regression). Th ere was an average temperature rise of 0.57 degrees C from the day prior to the day of the SP, compared with a 0.08 degrees C fall on the days without SP, This difference is statistically significant and was consistent over t he four seasons and both years, Seventy-three percent of the SP cases were clustered. A relationship between SP and thunderstorms was found. Conclusions: AP differences do not seem to influence the chance of developi ng SP. SP occurs in clusters, and more often 1 to 2 days after thunderstorm s, Whether the identified temperature rise prior to the SP is a causative f actor is unlikely; coexisting weather phenomena might explain this unexpect ed finding and should be studied in the future.