Table 1.

Acid–base characteristics of cerebrospinal fluid of the study population

Variables	Controls (n = 25)	SAH (n = 20)	p value
pH	7.35 ± 0.02	7.34 ± 0.06	0.69
PCO2 (mm Hg)	46 ± 3	40 ± 4	< 0.001
ATOT (mmol/L)	1.2 ± 0.2	1.2 ± 0.5	0.95
SID (mmol/L)	26.5 ± 1.4	23.1 ± 2.3	< 0.001
Na+ (mmol/L)	141 ± 1	143 ± 3	0.007
K+ (mmol/L)	2.8 ± 0.1	2.6 ± 0.5	0.07
Ca2+ (mmol/L)	0.99 ± 0.02	0.98 ± 0.06	0.22
Mg2+ (mmol/L)	1.10 ± 0.04	1.15 ± 0.06	0.002
Cl− (mmol/L)	120 ± 2	123 ± 4	0.001
Lac− (mmol/L)	1.4 ± 0.2	3.3 ± 1.3	< 0.001
HCO3− (mmol/L)	24.7 ± 1.5	21.7 ± 2.4	< 0.001
Phosph− (mEq/L)	0.77 ± 0.08	0.66 ± 0.20	0.02
Alb− (mEq/L)	0.19 ± 0.14	0.30 ± 0.23	0.05
Osmolarity (mOsm/L)	285 ± 3	290 ± 7	0.001
Gluc (mg/dL)	59 ± 7	74 ± 14	< 0.001
Hb (g/dL)	0.0 ± 0.0	0.3 ± 0.3	< 0.001
RBC (× 106/µL)	0.00 ± 0.00	0.11 ± 0.12	< 0.001
WBC (cells/µL)	2 ± 2	359 ± 562	0.003

Data are expressed as mean ± standard deviation

Alb⁻, ionized albumin concentration, A_TOT, total amount of weak noncarbonic acids, Ca²⁺, ionized calcium concentration, Cl⁻, chloride concentration, Gluc, glucose concentration, Hb, hemoglobin concentration, HCO₃⁻, bicarbonate concentration, K⁺, potassium concentration, Lac⁻, lactate concentration, Mg²⁺, magnesium concentration, Na⁺, sodium concentration, PCO₂, partial pressure of carbon dioxide, Phosph⁻, ionized phosphate concentration, RBC, red blood cell count, SAH, aneurismal subarachnoid hemorrhage, SID, strong ion difference, WBC, white blood cell count