Table 2

“Personal best” PEFR values with ranges for estimating severity of acute asthma episode

If patient’s “personal best” peak flow meter reading is:	Normal variation above:	Moderate acute asthma	Severe acute asthma	Life threatening acute asthma less than:
100	80	50 to 80	33 to 50	33
125	100	63 to 100	41 to 63	41
150	120	75 to 120	50 to 75	50
175	140	88 to 140	58 to 88	58
200	160	100 to 160	66 to 100	66
225	180	113 to 180	74 to 113	74
250	200	125 to 200	83 to 125	83
275	220	138 to 220	91 to 138	91
300	240	150 to 240	99 to 150	99
325	260	163 to 260	107 to 163	107
350	280	175 to 280	116 to 175	116
375	300	188 to 300	124 to 188	124
400	320	200 to 320	132 to 200	132
425	340	213 to 340	140 to 213	140
450	360	225 to 360	149 to 225	149
475	380	238 to 380	157 to 238	157
500	400	250 to 400	165 to 250	165
525	420	263 to 420	173 to 263	173
550	440	275 to 440	182 to 275	182
575	460	288 to 460	190 to 288	190
600	480	300 to 480	198 to 300	198