Temporary reversal of serum to cerebrospinal fluid glycerol concentration gradient after intravenous infusion of glycerol.
Glycerol 50 g infused i.v. over 2 to 6 h is widely used to treat cerebral oedema in patients with acute stroke. Its transit through the blood-cerebrospinal fluid barrier in subjects with uninflamed meninges has now been examined. In 7 patients with an external ventriculostomy for occlusive hydrocephalus, each of whom was given 500 ml of a 10% solution IV over 4 h, serum and CSF were repeatedly sampled during and after the infusion and glycerol was measured enzymatically. The highest serum glycerol level of 191-923 mg/l was observed at the end of the infusion. The maximum CSF glycerol of 18.7-110.8 mg/l was attained 0-1 h after the end of the infusion. Elimination both from serum and CSF approximated a single-exponential decay; the elimination half-life from serum was 0.29-0.56 h compared to 1.03-3.68 h from CSF. In six of the seven cases there was a temporary reversal of the serum/CSF concentration gradient during glycerol elimination. The ratios of the AUCs of CSF and serum, which describe the overall penetration of glycerol into CSF, ranged from 0.09-0.31. In conclusion, the serum level of glycerol produced by giving 50 g IV glycerol over 4 h may not be sufficiently high reliably dehydrate to brain tissue in many patients, and the slow elimination of glycerol from the CSF may be related to the so-called rebound phenomenon.
Nau
R
R
Department of Neurology, University of Göttingen, FRG.
Prins
F J
FJ
Kolenda
H
H
Prange
H W
HW
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001812:Blood-Brain Barrier / Q000502:physiology; D001929:Brain Edema / Q000188:drug therapy / Q000378:metabolism*; D005260:Female; D005990:Glycerol / Q000008:administration & dosage / Q000097:blood* / Q000134:cerebrospinal fluid* / Q000493:pharmacokinetics; D006207:Half-Life; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged
D005990:Glycerol