What do systematic reviews say?

High initial concentration vs low initial concentration

High initial concentration showed no clear difference in cough compared with low initial concentration (low certainty).

• High initial concentration versus low initial concentration sevoflurane for inhalational induction of anaesthesia 2016 · Cochrane Headline outcomes only
  OR 1.23 [0.53, 2.81]
  8 studies · 589 participants
  Low