Hi Everyone! Can anyone help with this query. I have googled and asked but cannot find an answer! I had my first ever spirometry test 2 days ago, I am 49 and a smoker. Test was arranged as I have episodes of waking in the early hours with wheezing or coughing although pretty much ok at other times of the day and night. I have never had a chest infection and a chest x ray was clear.Anyway the test was started and my first 3 blows where good ''green light Good Blow!'' and then I had a reversibility test was given an inhaler of salbutamol waited 15 mins Whilst blood was taken to test for Aspergillus and Alpha 1 Antitrypsin and then asked to blow again. This time however I couldn't seem to get it right and got 4 amber lights However the practice nurse said that could because it gets more difficult if you have an obstruction! Anyway she showed me the results and a print out of my results curves and all and said I had mild copd! My results were as follows...

FEV1 pred 2.45 pre best 2.29 93% ( post ) best 2.39 97%

FVC pred 2.88 pre best 3.65 127% (post ) best 4.04 140%

PEF pred 370 pre best 394 106% ( post ) best 405 110%

FEV1/FVC predicted 79.7% pre best 62.7% (post ) best 59.1%

FEF25-75% predicted 3.24 pre best 1.08 33% (post ) best 0.94 29%

It did also say interpret with care! They dont make sense to me! How can I have mild obstruction yet have such high FVC percentages and scored 93% and 97% on my FEV1 results? and have a PEF of 106 and 110 percent respectivly! I understand it is the ratio that determines the final percentage, so if I didnt blow out for so long ( it made me light headed) would I have scored a lower FVC and in effect lower the ratio? wouldit have been better Is this correct? Sorry for the long post but it is very puzzling! Any help advise is appreciated!

3 Replies

  • Hi, why not ring the BLF helpline on 03000 030 555 they are the experts.


  • Hi

    Pollyj beat me to it - yes please call the Helpline to discuss - it's never straightforward helpling someone understand spirometry readings just from a list of figures - always other questions needing to be asked etc. The numbesr above but just incase - 03000 030 555.



  • Its the fev1/fvc ratio that determines obstruction. 2450ml/2880 ml = 62.7%

    Anything below 70% classed as obstructive.

    You have above normal lung fvc but your fev1is only 93% of predicted.

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