patients with copd or asthma frequently experience exacerbations of their illness . studies from norway and the uk have shown that each year ~50% of copd patients experience an exacerbation that leads to a visit to a general practitioner ( gp ) , in - hospital treatment , or self - administered treatment with antibiotics or systemic corticosteroids.1,2 in a study from the united states , ~25% of asthma patients reported to use a short course with oral corticosteroids during a period of 3 months.3 treatment with systemic corticosteroids is recommended in both severe copd exacerbations4,5 and asthma attacks.6,7 such medication counteracts the inflammatory response in the bronchial tree , and by doing so , alleviates the accompanying bronchial obstruction . in asthma attacks , there is firm evidence for a favorable effect of systemic corticosteroids,6 for copd exacerbations the evidence refers mainly to clinical trials in hospitalized patients.4 in copd guidelines , the criteria for starting such treatment are not clear cut , but it is often recommended when symptoms are not relieved after stepping up treatment with inhaled bronchodilators.8 benefit from systemic corticosteroid treatment has to be weighed against adverse effects , such as increased fragility of the bones and increased blood levels of glucose.4 improvement in lung function has been a main outcome measure in studies on the effects of systemic corticosteroids.9,10 this implies that the acute deterioration of lung function associated with the exacerbation is a main target for the systemic corticosteroids . it would , therefore , probably be useful , when deciding on prescribing systemic corticosteroids , to know whether the patient actually suffers from increased bronchial obstruction and if so , to which degree ? however , doing spirometry in the acute phase of a copd exacerbation is not recommended in the global initiative for chronic obstructive lung disease ( gold ) guidelines,5 and it might not be convenient in all cases with asthma attacks . other sources of information that could reflect increased bronchial obstruction could be the symptoms of the patient , as well as chest findings and assessment of oxygen saturation ( spo2 ) by pulse oximetry . the aim of this study was to describe how these clinical findings are associated with a decrease in lung function during exacerbations . we also wanted to find out whether the strength of these associations would be affected when they could be described in terms of change from stable state . this observational prospective study was carried out in seven general practice offices in the north and south of norway . patients aged 40 years or older registered in the electronic medical record with a diagnosis of asthma or copd ( or both ) in the previous 5 years were identified , and a random sample of 1,111 patients was invited to participate . of the 380 patients who met for baseline registration between april 2009 and march 2010 , 376 were considered to be in a stable phase of their disease and were included in the study . out of those , 210 were diagnosed with asthma by their gps , 74 with copd , and 92 with both asthma and copd.11 they were all asked to visit their gp within 23 days if they experienced exacerbations of their lung disease the following 12 months . all participants gave written consent , and the study was approved by the regional committee for medical and health research ethics in north norway . respiratory symptoms the previous week and relevant quality of life items were examined using the norwegian translation of the clinical copd questionnaire ( ccq).12 in the ccq , the symptoms  short of breath at rest  ,  short of breath doing physical activities  , coughing , and production of phlegm were classified into scores from 0 ( never ) to 6 ( almost all the time ) , and a mean score of respiratory symptoms was calculated . the ccq also contains questions on depression and concern about the disease getting worse with the same score system and four questions on activity limitation due to the illness , also with a score system from 0 ( not limited at all ) to 6 ( totally limited ) . smoking habit and hospitalizations due to the lung disease the previous year were reported on a separate questionnaire . on a pop - up questionnaire in the electronic medical record the examining gp recorded comorbidities and treatment given , including antibiotics and systemic corticosteroids for exacerbations the previous year . exacerbation of asthma or copd the year before baseline was defined as exacerbations that were treated with antibiotics and/or systemic corticosteroids or ended with hospitalization , a definition previously used for copd exacerbations.1 the gps also reported the presence of wheezes , crackles , diminished breath sounds , and prolonged expiration after auscultation of the lungs . c - reactive protein ( crp ) was analyzed using near patient tests : afinion as100 analyzer , orion quickread crp , or abx micros crp , which all could display values down to 8 mg / l . spo2 was measured by a digital handheld pulse oximeter , onyx ii model 0550 ( nonin medical , inc . , spirometry was carried out after the pulse oximetry , following the european respiratory society / american thoracic society guidelines.13 spirare sps310 spirometers ( diagnostica as , oslo , norway ) were used . post - bronchodilator spirometry was carried out 20 minutes after inhalation of 0.4 mg salbutamol . the post - bronchodilator forced expiratory volume in 1 second ( fev1 ) and forced vital capacity ( fvc ) were used in the analyses . norwegian reference values for spirometry were applied.14 the participants filled in the ccq , this time concerning the previous 24 hours . respiratory symptoms the previous 24 hours were also reported by the gps based on history taking on a pop - up questionnaire and shortness of breath , coughing , phlegm production , and wheezing were classified into three grades : 1 ) not present or as normal , 2 ) more bothersome than normal , and 3 ) very bothersome . chest findings , the crp value , and pulse oximetry were recorded as done at baseline . lung function testing was also carried out with the same procedure , but post - bronchodilator spirometry was not carried out . a significant drop in fev1was defined as a drop of 10% from baseline15 and of at least 200 ml . how such a drop in fev1 was associated with baseline characteristics and symptoms , signs and test results at exacerbation was analyzed by chi - square test , fischer s exact test ( dichotomous variables ) , and mann  whitney test ( the ccq variables ) . significant decreases in spo2 were defined as a reduction of at least 2% to 95% and 92% , respectively . likelihood ratios were calculated for findings significantly associated with the fixed drop in fev1 using online software ( m.k . associations with percentage change in fev1 from baseline were analyzed by linear regression making it possible to have the degree of change as outcome . this observational prospective study was carried out in seven general practice offices in the north and south of norway . patients aged 40 years or older registered in the electronic medical record with a diagnosis of asthma or copd ( or both ) in the previous 5 years were identified , and a random sample of 1,111 patients was invited to participate . of the 380 patients who met for baseline registration between april 2009 and march 2010 , 376 were considered to be in a stable phase of their disease and were included in the study . out of those , 210 were diagnosed with asthma by their gps , 74 with copd , and 92 with both asthma and copd.11 they were all asked to visit their gp within 23 days if they experienced exacerbations of their lung disease the following 12 months . all participants gave written consent , and the study was approved by the regional committee for medical and health research ethics in north norway . respiratory symptoms the previous week and relevant quality of life items were examined using the norwegian translation of the clinical copd questionnaire ( ccq).12 in the ccq , the symptoms  short of breath at rest  ,  short of breath doing physical activities  , coughing , and production of phlegm were classified into scores from 0 ( never ) to 6 ( almost all the time ) , and a mean score of respiratory symptoms was calculated . the ccq also contains questions on depression and concern about the disease getting worse with the same score system and four questions on activity limitation due to the illness , also with a score system from 0 ( not limited at all ) to 6 ( totally limited ) . smoking habit and hospitalizations due to the lung disease the previous year were reported on a separate questionnaire . on a pop - up questionnaire in the electronic medical record the examining gp recorded comorbidities and treatment given , including antibiotics and systemic corticosteroids for exacerbations the previous year . exacerbation of asthma or copd the year before baseline was defined as exacerbations that were treated with antibiotics and/or systemic corticosteroids or ended with hospitalization , a definition previously used for copd exacerbations.1 the gps also reported the presence of wheezes , crackles , diminished breath sounds , and prolonged expiration after auscultation of the lungs . c - reactive protein ( crp ) was analyzed using near patient tests : afinion as100 analyzer , orion quickread crp , or abx micros crp , which all could display values down to 8 mg / l . spo2 was measured by a digital handheld pulse oximeter , onyx ii model 0550 ( nonin medical , inc . , spirometry was carried out after the pulse oximetry , following the european respiratory society / american thoracic society guidelines.13 spirare sps310 spirometers ( diagnostica as , oslo , norway ) were used . post - bronchodilator spirometry was carried out 20 minutes after inhalation of 0.4 mg salbutamol . the post - bronchodilator forced expiratory volume in 1 second ( fev1 ) and forced vital capacity ( fvc ) were used in the analyses . the participants filled in the ccq , this time concerning the previous 24 hours . respiratory symptoms the previous 24 hours were also reported by the gps based on history taking on a pop - up questionnaire and shortness of breath , coughing , phlegm production , and wheezing were classified into three grades : 1 ) not present or as normal , 2 ) more bothersome than normal , and 3 ) very bothersome . chest findings , the crp value , and pulse oximetry were recorded as done at baseline . lung function testing was also carried out with the same procedure , but post - bronchodilator spirometry was not carried out . a significant drop in fev1was defined as a drop of 10% from baseline15 and of at least 200 ml . how such a drop in fev1 was associated with baseline characteristics and symptoms , signs and test results at exacerbation was analyzed by chi - square test , fischer s exact test ( dichotomous variables ) , and mann  whitney test ( the ccq variables ) . changes from baseline were found by subtracting baseline values from the values at exacerbation . significant increase in crp was defined as an increase of at least 10 mg significant decreases in spo2 were defined as a reduction of at least 2% to 95% and 92% , respectively . likelihood ratios were calculated for findings significantly associated with the fixed drop in fev1 using online software ( m.k . associations with percentage change in fev1 from baseline were analyzed by linear regression making it possible to have the degree of change as outcome . during the 1-year follow - up period , 109 patients visited their gp due to one or more exacerbations . for patients who visited the gp with several exacerbations , the first exacerbation was , as a rule , included in the analysis . however , 21 patients were excluded due to incomplete data from the exacerbations , in most cases because spirometry was not done . seventeen gps took part in the examinations of the 88 included patients at baseline , whereas 34 gps shared the examinations during the exacerbations , and 41 patients ( 47% ) were examined by the same gp both times . the mean age of the patients at baseline was 63 years , and 66% were female . a copd diagnosis ( or both asthma and copd ) had been given to 48 ( 55% ) patients at baseline , and patients with a copd diagnosis had significantly more frequent history of exacerbation the previous year . they were also different from the patients in the asthma group in other ways ( table 1 ) . the distribution of fev1 at baseline and at exacerbation is shown in figure 1 , with predicted mean values of 76.1% and 70.8% , respectively . among the asthma patients , the corresponding fev1% predicted values were 87.5 and 83.0 and among the copd patients , 61.2 and 54.7 . the distribution of change from baseline is shown in figure 2 . a significant drop in fev1 at exacerbation ( 10% and at least 200 ml ) the patients with this drop in lung function had more frequent copd diagnosis at baseline than those without ( p=0.04 , table 2 ) . during spirometry at baseline 75 patients ( 85% ) expired for more than 6 seconds , at exacerbation the corresponding number was 67 ( 76% ) . ten of the 13 patients who reported very bothersome wheezing had a significant drop in fev1 ( p=0.001 , table 2 ) . in the asthma group , only two patients had this symptom , but a significant drop in fev1 was found in both . an abnormal finding by chest auscultation was found in 68 patients ( 77% ) , and a new sign ( not recorded at baseline ) was found in 48 patients ( 55% ) . any abnormal chest sign , whether new or not , was recorded more frequently in patients with a significant drop in fev1 ( table 2 ) compared with other patients . crackles  was associated with a drop in fev1 , whereas  wheezes  was not . in 26 patients ( 30% ) , one or more of the four chest signs were recorded both at baseline and exacerbation , and with similar frequency whether the same gp performed the auscultation at both occasions , 24% and 34% , respectively ( p=0.3 ) . spo2 values 92% were found in 11 patients , and in 10 of these , the saturation had dropped 2% or more between baseline and exacerbation . this drop in spo2 was associated with a significant drop in fev1 ( p=0.02 ) . there was a median increase in ccq score of 1.25 for respiratory symptoms between baseline and exacerbation , but no difference was found between the patients with a significant drop in fev1 and the other patients ( table 3 ) . the diagnostic value of findings , significantly indicating a drop in fev1 , is shown in table 4 . the asthma and copd subgroups did not differ when it came to likelihood ratios of very bothersome wheezing experienced by the patients and crackles on auscultation . a diagnostic value of spo2 dropping to below 93% was only found in the copd group . when the percentage drop in fev1 was used as outcome in univariable linear regression , the fev1/fvc ratio was the strongest predictor among the baseline characteristics ( table 5 ) . treatment with long - acting beta - agonist / inhaled corticosteroids seemed to slightly counteract the drop in fev1 , but this association was not statistically significant . very bothersome wheezing during exacerbation , as experienced by the patient , was the strongest indicator of change in fev1 among the symptoms , and prolonged expiration and any abnormal auscultation finding were now stronger indicators than crackles . a decrease in spo2 of at least 2% to a value of 92% was still strongly associated with a drop in fev1 . we have attempted to find alternatives to spirometry in assessing drop in lung function during asthma and copd exacerbations . one strong indicator of a significant drop in lung function was increased wheezing as experienced by the patient . as far as we know , this finding has not been reported previously to be a sign of a drop in lung function . patient experienced wheezing was a stronger predictor of drop in lung function than were wheezes on auscultation . decreased spo2 measured as spo2 92% was also strongly associated with a drop in fev1 . only one copd patient had spo2 92% at baseline , telling us that this is a relevant finding for primary care . a drop in fev1 was most frequently found in the patients with a copd diagnosis , and the fev1/fvc ratio at baseline was strongly associated with a change in lung function in the linear regression , indicating that the severity of the copd should be taken into account . we have attempted to find alternatives to spirometry in assessing drop in lung function during asthma and copd exacerbations . one strong indicator of a significant drop in lung function was increased wheezing as experienced by the patient . as far as we know , this finding has not been reported previously to be a sign of a drop in lung function . patient experienced wheezing was a stronger predictor of drop in lung function than were wheezes on auscultation . decreased spo2 measured as spo2 92% was also strongly associated with a drop in fev1 . only one copd patient had spo2 92% at baseline , telling us that this is a relevant finding for primary care . a drop in fev1 was most frequently found in the patients with a copd diagnosis , and the fev1/fvc ratio at baseline was strongly associated with a change in lung function in the linear regression , indicating that the severity of the copd should be taken into account . as part of a prospective study with baseline examinations , we were able to collect post - bronchodilator spirometry at stable state in all patients . the spirometry was well performed , and although fewer patients expired for more than 6 seconds during exacerbation than at baseline , there are reasons to believe that valid fev1 values were obtained . the cutoff level of 10% for drop in fev1 may be regarded as arbitrary , and the results are strengthened by using the percentage drop in fev1 as continuous outcome variable in linear regression . however , we did not find any great benefit of taking the baseline findings into account . one good reason for doing this is the difficulties in differentiating between asthma and copd in many patients with obstructive lung disease.11,16 a second justification is the similar challenges in the two diseases when it comes to treating exacerbations with oral corticosteroids . this is rather a small clinical study , and the results should be interpreted with caution . not all patients who were assessed during exacerbation were included , due to incomplete data collection in the practices . whereas the collection of baseline data was well organized , the participating practices were not always as prepared when it came to the exacerbations . this has probably not resulted in any systematic selection bias influencing the association between findings and drop in lung function . we have not found studies evaluating wheezing , as experienced by patients , as a sign of drop in lung function , only as an independent predictor of copd in general.17 wheezing is not one of the items in score sheets for health status in copd patients , such as the ccq12 and the copd assessment test ( cat)18 and neither in the exacerbations of chronic pulmonary disease tool ( exact).19 decreased spo2 during copd exacerbations has been shown in previous studies,20,21 but decreased spo2 has not previously been linked to the magnitude of drop in fev1 . a strong link between reduced fev1 and reduced pulse oximetry values has been shown in several studies , also among asthma and copd patients in general practice.22 introduction of pulse oximeters in primary care was recommended in 2010,23 and our results support this development . in a previous publication from this project , we showed that decreased spo2 predicted treatment with oral corticosteroids.24 there was , however , no association between patient experienced wheezing and the prescribing of oral corticosteroids ( among the 13 patients with very bothersome wheezing , 6 [ 46.2% ] were treated with oral corticosteroids , compared to 40% in the remaining patients ) . one may question why not just spirometry can be used in the assessment of lung function during asthma and copd exacerbations . it was successfully applied in this study and has also been performed in other studies without reports of adverse experiences.9,10 the recommendation in the gold guidelines , not to use spirometry during exacerbations,5 is probably based on experiences from hospital and with severely ill outpatients . in primary care , the majority of copd patients have a mild or moderate disease , as was also the case in this study . when a spirometry result from stable state is available and performed within the previous year , a new spirometry can usually give a valid measure of drop in lung function . however , coughing may force the patient to terminate the expiratory maneuver too early , and this may explain why the expiration lasted less than 6 seconds more frequently during exacerbation than at baseline in this study . clinical assessment without spirometry is often needed . to find wheezes by auscultation of the chest wheezes were recorded as present or absent , but their intensity in terms of number and duration was not documented . consequently , when wheezes were recorded as present in both stable state and during exacerbation , we had no information about the change in the intensity . the difficulties in interpreting auscultation findings also relate to crackles and prolonged expiration , which were stronger indicators of a drop in fev1 than wheezes in this study . to ask primary care patients with asthma or copd exacerbations about wheezing seems to be a simple and a rational approach when assessing change in lung function . . increased  wheezing  and low pulse oximetry values are probably useful to take into account when treatment with oral corticosteroids is considered . however , we do not know to which degree treatment with oral corticosteroids should be based on a drop in fev1 . more studies are needed to help identify the clinical findings that can be helpful in the difficult decision to prescribe this potent medication .
backgroundwhen 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 fev1 during exacerbations.methodsin 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 fev1 were outcomes 
 when possible indicators were evaluated.resultsthree 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 , 1.921.7 ) . 
 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 spo2 were also very strong predictors of change in fev1 in linear regression adjusted for age , gender , and baseline fev1% predicted.conclusionincreased wheezing , as experienced by the patient , and a decreased spo2 value 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 .