Table 1: Postoperative blood sample values and methemoglobin levels.

Postop 15th min 1st hour 2nd hour 3rd hour 5th hour 7th hour 8th hour 10th hour 24th hour 48th hour
Ph 7.39 7.49 7.50 7.55 7.51 7.41 7.49 7.44 7.41 7.41
PO2 275 204 121 120 152 163 171 159 152 213
PCO2 31.4 30 29 26 26 27 30 32 35 37
HCO3 23 23 24 22 21 17 25 23 24 23
SO2 99 99 - - - 97 98 99 99 99
SPO2 95 92 89 90 92 95 99 100 100 100
MetHb 2.4 5.8 16 19.8 20 14.5 7.2 2.8 0.9 0.5
FiO2 50 50 80 100 80 60 50 40 40 35
Lactate 1.8 2.1 2.3 1.8 1.5 1.1 1.6 1.3 1.1 2.0

Abbreviations: Postop: Postoperative; PO2: Partial Pressure of Oxygen; PCO2: Partial Pressure of Carbon Dioxide; HCO3: 4 Bicarbonate; SO2: Arterial Oxygen Saturation; SPO2: Pulse Oximetry Saturation; MetHb: Methemoglobin; FiO2: 5 Fraction of Inspired Oxygen.