title: Drop in lung function during asthma and COPD exacerbations - can it be assessed without spirometry?
abstract: BACKGROUND
  When assessing patients with exacerbation of asthma or COPD, it may be useful to know the drop in forced expiratory volume in 1 second (FEV1) compared with stable state, in particular when considering treatment with oral corticosteroids. The objective of the study was to identify indicators of drop in FEV1during exacerbations.
  
  
  METHODS
  In this prospective multicenter study from primary care, patients diagnosed with asthma or COPD were examined at stable state and during exacerbations the following year. Symptoms, chest findings, and pulse oximetry were recorded, and spirometry was performed. A fixed drop in FEV1(10% and ≥200 mL) and percentage change in FEV1were outcomes when possible indicators were evaluated.
  
  
  RESULTS
  Three hundred and eighty patients attended baseline examination, and 88 with a subsequent exacerbation were included in the analysis. Thirty (34%) had a significant drop in FEV1(10% and 200 mL). Increased wheezing was the only symptom associated with this drop with a likelihood ratio of 6.4 (95% confidence interval, 1.9-21.7). Crackles and any new auscultation finding were also associated with a significant drop in FEV1, as was a ≥2% drop in oxygen saturation (SpO2) to ≤92% in the subgroup diagnosed with COPD. Very bothersome wheezing and severe decrease in SpO2were also very strong predictors of change in FEV1in linear regression adjusted for age, gender, and baseline FEV1% predicted.
  
  
  CONCLUSIONS
  Increased wheezing, as experienced by the patient, and a decreased SpO2value strongly indicated a drop in lung function during asthma and COPD exacerbations and should probably be taken into account when treatment with oral corticosteroids is considered.
authors.affiliation: General Practice Research Unit, Department of Community Medicine, UIT The Arctic University of Norway, Tromsø, Norway.
authors.forename: Hasse
authors.initials: H
authors.lastname: Melbye
authors.affiliation: General Practice Research Unit, Department of Community Medicine, UIT The Arctic University of Norway, Tromsø, Norway.
authors.forename: Salwan
authors.initials: S
authors.lastname: Al-Ani
authors.affiliation: General Practice Research Unit, Department of Community Medicine, UIT The Arctic University of Norway, Tromsø, Norway; Department of Family Medicine, CAPHRI, Maastricht University, Maastricht, the Netherlands.
authors.forename: Mark
authors.initials: M
authors.lastname: Spigt
mesh_terms: D000280:Administration, Inhalation; D000284:Administration, Oral; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage; D000368:Aged; D001249:Asthma / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D015415:Biomarkers / Q000097:blood; D001993:Bronchodilator Agents / Q000008:administration & dosage; D018450:Disease Progression; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000187:drug effects / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009664:Norway; D010092:Oximetry; D010100:Oxygen / Q000097:blood; D000071066:Patient Reported Outcome Measures; D011237:Predictive Value of Tests; D011320:Primary Health Care; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D012135:Respiratory Sounds; D012307:Risk Factors; D012720:Severity of Illness Index; D013147:Spirometry
chemical_list: D000305:Adrenal Cortex Hormones; D015415:Biomarkers; D001993:Bronchodilator Agents; D010100:Oxygen
keywords: bronchial obstruction; diagnostic tests; primary care; systemic corticosteroids