Background: Deep inhalation induced broncho-dilation response (reflected by change in PEFR from the first to last of a sequence of 3 blows) is attenuated in acute asthma because of airway inflammation. However its clinical value in predicting length of stay remains unaddressed.Aim : To establish a relation between last to first PEFR ratio in the sequence and length of hospital stay in patients with acute asthma.
90 consecutive patients presenting with acute exacerbation of asthma were recruited. Peak expiratory flow rate (PEFR) was measured with the patient seated and using a mini-Wright flow meter. The measurement was taken as the best of three blows from total lung capacity with no breath hold. Last to first PEFR ratio was derived by dividing the third peak expiratory flow by the first and the log of the ratio was related to length of stay (LOS) by logistic regression with age ,sex, PEFR %,and GINA stage as other independent variables. The patients were managed according to GINA guidelines.
. 28 patients had a last: first PEFR ratio <1, and 62 had a ratio 1. Admission characteristics were similar in the two groups except for GINA stage. The mean LOS for the group with a ratio <1 was 2.64 + 0.73 compared with 2.08 + 0.32 for the group with a ratio 1 [mean difference = 0.5622 (95%CI 0.34 to 0.78); P<0.001]. Logistic regression showed that admission PEFR % pred. (r=−0.47, P=0.001) and log last :first ratio (r=−0.56, P=0.001) but not GINA stage (r=0.24, P=0.2) and age (r = 0.1. p = 0.3 )were independently related to LOS.
PEFR sequence at arrival is an independent predictor of length of hospital in acute severe asthma cases.
in acute asthma attenuation of deep inhalation induced broncho-dilation is an independent predictor of longer length of stay.
Anupam Singh, No Financial Disclosure Information; No Product/Research Disclosure Information