Table 2. Arterial blood gas values at different perioperative time points.

Arterial blood gas values at baseline (room air), during hypoventilation prior to naloxone administration (while receiving supplemental oxygen), and after naloxone administration following extubation (on face mask). Values demonstrate acute hypercapnic respiratory acidosis with subsequent improvement after opioid reversal.

Parameter	Baseline (room air)	Pre-naloxone	Post-naloxone
pH	7.38	7.14	7.26
pCO₂ (kPa)	5.70	9.50	6.30
pO₂ (kPa)	9.00	21.70	15.5
HCO₃⁻ (mmol/L)	25.40	24.20	21.10
Base excess	0.1	-6.2	-6.0
Lactate (mmol/L)	0.8	1.2	1.2
SaO₂ (%)	94.2	99.7	98.4