. 2023 May 16;22:47. doi: 10.1186/s12938-023-01111-0

Table 4.

Update rules for FIO $_{2}$ based on current SpO $_{2}$ value

SpO $_{2}$	Description	Update rule	Update time
> high target + 4	Greatly above target	Decrease FIO $_{2}$ by 0.1	100 s
> high target + 2	Above target	Decrease FIO $_{2}$ by 0.05	100 s
> high target	Slightly above target	Decrease FIO $_{2}$ by 0.02	100 s
> target middle	Upper target region	If stable: decr. 0.02, else: no change	20 min
> low target	Lower target region	No change	–
< low target	Slightly below target	Increase FIO $_{2}$ by 0.02	40 s
< low target -2	Below target	Increase FIO $_{2}$ by 0.05	20 s
$\leq$ 85	SpO $_{2}$ low state	Set FIO $_{2}$ to 1.0	Immediately