Seven RCTs (n=373) were included. The sample size ranged from 28 to 95.
Heart rate (7 trials).
Two of 6 trials using at least 3 mL of adrenaline found significant increases in heart rate. The first of these trials found significant increases in heart rate an hour after the last of three nebulisations with 4 mL adrenaline compared with saline control (151 versus 138 beats per minute, bpm, P<0.001). The second positive trial found a significant increase in heart rate 40 minutes after nebulisation with 3 mL adrenaline compared with before nebulisation (7 bpm increase, P<0.05). One of the other trials found a reduction (of 5 to 10 bpm) in heart rate after 5 mL adrenaline, but the statistical significance was not reported. The other 3 trials showed no significant effects of 3 to 4 mL adrenaline on heart rate. The trial using 0.5 mL adrenaline also found no significant effects on heart rate.
Systemic arterial pressure (2 trials).
Neither trial found any statistically significant effect of adrenaline on systemic arterial pressure.
Other adverse effects.
Pallor (3 trials): one of the 3 trials using at least 3 mL of adrenaline found an increase in pallor after nebulisation with two doses of adrenaline compared with salbutamol (47.6% versus 14.3% at 30 minutes, P<0.05; 38.1% versus 14.3% after 60 minutes, P=0.06). Other: one trial reported a similar number of patients with other adverse effects with adrenaline and budesonide. Six of 31 patients (19%) treated with 4 mL adrenaline versus 6 of 35 patients (17%) treated with budesonide had adverse effects such as hyperactivity, vomiting, erythema, diarrhoea, wheezing and epistaxis.