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Table 2 Acid–base and electrolyte data

From: Acetazolamide-mediated decrease in strong ion difference accounts for the correction of metabolic alkalosis in critically ill patients

Acid–base and electrolyte data Baseline t = 24
PH 7.49 (7.48–7.51) 7.46 (7.44–7.48)
PaCO2 (kPa) 5.7 (5.1–6.1) 5.3 (4.9–5.9)
Bicarbonate (mmol/l) 31.5 (29.5–33.7) 28.6 (26.3–30.3)
Sodium (mmol/l) 141 (139–145) 142 (139–145)
Potassium (mmol/l) 3.7 (3.7–4) 3.8 (3.4–3.9)
Chloride (mmol/l) 106 (102–107) 108 (107–110)
Creatinine (μmol/l) 64 (49–95) 65 (49–101)
Lactate (mmol/l) 1.4 (1.2–1.8) 1.5 (1.2–1.7)
Albumin (g/l) 16 (14–20) 17 (15–20)
Apparent SID (mEq/l) 41.7 (39.1–44.0) 39.4 (36.4–41.4)
Effective SID (mEq/l) 39.0 (37.3–40.3) 35.6 (32.9–37.7)
SIG (mEq/l) 2.4 (1.5–4.4) 3.1 (2.1–4.8)
Sodium–chloride effect (mEq/l) -2.0 (-3.5 to +0.5) -3.0 (-7.5 to -1.5)
  1. Shown are baseline acid–base and electrolyte data (median [interquartile range]) for 15 patients before administration of 500 mg acetazolamide (baseline) and after 24 hours (t = 24). The serum apparent SID (SIDapp) was calculated using the following equation: SIDapp = [Na+] + [K+] + [Ca2+] + [Mg2+] - [Cl-] - [lactate-]. The serum effective SID (SIDeff) was calculated using the following equation: SIDeff = 12.2 × PCO2/(10-pH) + [albumin] × (0.123 × pH - 0.631) + [PO4-] × (0.309 × pH - 0.469). The SIG was calculated using the following equation: SIG = SIDapp - SIDeff. The sodium–chloride effect was calculated using the formula [Na+] - [Cl-] - 38. PaCO2, arterial carbon dioxide tension; SID, strong ion difference; SIG, strong ion gap.