“…During an acute asthma attack, the measurement of lung function by FEV 1 (forced expiratory volume in 1 s) or PEF is strongly recommended whenever possible, without delaying therapy. These tests define the severity of the attack (mild for PEF or FEV 1 values >80%, moderate for values between 60 and 80% and severe if PEF or FEV 1 are <60%) and assess the response to therapy [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 ...…”