Table 1.

Composition of human spinal fluid and solutions used in neurosurgery

Component	Normal human CSF	ACF	NS	LR
Na+ (mEq/L)	145	145	154	130
K+ (mEq/L)	2.8	2.8	0	4
Mg2+ (mEq/L)	2.2	2.2	0	0
Ca2+ (mEq/L)	2.3	2.3	0	3
Cl− (mEq/L)	111.9	129	154	109
P (mmol/L)	1.1	1.1	0	0
HCO3− (mEq/L)	23.1	23.1	0	0
Lactate− (mEq/L)	0	0	0	28
Glucose (g/L)	0.61	0.61	0	0
Osmolality ratio	≈1	≈1	1	≈0.9
pH	7.307	≈7.3	≈6.3	≈6.7

Abbreviations: CSF cerebrospinal fluid, ACF artificial cerebrospinal fluid, NS normal saline, LR lactated Ringer’s solution