A Retrospective Study on the Potentially Fatal Asthma

Lee, Jong Myung; Hwang, Youn Keun; Yun, Jong Soo; Kang, Cheon Il; Seo, Young Ik; Kim, Nung Soo; Koo, Seong Mo; Cho, Bong Kee; Kang, Young Mo; Lee, Choong Ki

Abstract

OBJECTIVES
A number of investigators have examined the possible pathophysiological mechanisms in patients who died from asthma, but the reasons for the increased incidence of death in patients with asthma are largely unknown. To elucidate the risk factors and possible causes of fatal asthma, we reviewed the clinical data of patients with potentially fatal asthma(PFA).
METHODS
We retrospectively studied the clinical and laboratory profiles of 35 PFA patients(43 episodes) who had been admitted at the Kyungpook University Hospital and Taegu Fatima Hospital in recent 5 years(1989. 7-1994. 6). Our criteria of PFA were defined as either respiratory arrest or an arterial carbon dioxide tension(PaCO2) greater than 50 mmHg or an altered state of consciousness, due to acute asthma.
RESULTS
1) Twenty four patients with PFA were female and 11 male. At the time of PFA episode, age distribution was between 16-65 year (42% between 36-49). 2) Seasonal distribution was 13 episodes between March and May, 13 June and August, 6 September and November, 11 December and February. 3) Previous hospitalization history due to asthmatic attack was noted in 81 percent, and 75 percent were relatively compliant to their therapy. 5) At visiting emergency room, 81 percent satisfied the criteria of PFA, whereas 19 percent during hospitalizatoin. 77 percent required mechanical ventilation, and 52 percent of them within 30 minutes after visiting. 6) Initial arterial blood gas analysis at emergency room showed marked hypercapnia(75 +/- 29 mmHg), hypoxemia(50 +/- mmHg) and acidosis(pH 7.14 +/- 0.15). Serum potassium levels were within normal ranges in 75 percent. 7) All, except one, showed no significant cardiac arrthymias. 8) Possible precipitating factors leading to PFA were respiratory tract infection in 31 episodes, ingestion of NSAIDs in 2, emotional upsets in 2, irritant air pollutions in 2, withdrawal of anti-asthma drugs in 1, and unknown causes in 5. 9) Nine of 16 patients were atopic, and majority of them showed positive reaction to Dermatophagoides antigen.
CONCLUSIONS
These results may suggest that PFA is mainly due to airway obstruction, and upper respiratory infection is an important precipitating factor leading to PFA. It is necessary to establish an appropriate plan for preventing PFA and related deaths.