Objective: To measure cerebrospinal fluid and plasma concentrations of nitr
ate and nitrite as indicators of nitric oxide production in adults after su
barachnoid hemorrhage (SAH).
Design: A prospective, clinical study.
Setting: Multidisciplinary intensive care unit.
Patients: Nine patients (three males and six females, aged 29-64 yrs) with
aneurysm-induced SAH were studied, Glasgow Coma Scale score on admission ra
nged from 9 to 15, Ruptured aneurysms were clipped within 72 hrs of ictus,
and then conventional hypervolemic, hemodilution, and induced hypertension
methods were applied.
Measurements and Main Results: Nitrate and nitrite concentrations of patien
ts were examined sequentially by a capillary zone electrophoresis every day
for 13 days. As a central group, cerebrospinal fluid was sampled from pati
ents (n = 9, six males and three females, aged 30-60 yrs) without neurologi
c disorders who underwent spinal taps for spinal anesthesia, and plasma fro
m healthy human volunteers (n = 43, 21 males and 22 females, aged 23-49 yrs
). There were no significant differences over time in cerebrospinal fluid n
itrate concentrations after SAH. Concentrations of cerebrospinal fluid nitr
ate after SAH were increased compared with control values. Plasma nitrate c
oncentration was decreased compared with control values, but the value on d
ay 14 was increased significantly (p < .05) compared with those during days
2-11, Plasma and cerebrospinal fluid nitrite concentrations after SAH were
similar to those in control subjects. Similar concentrations of nitric oxi
de metabolite in plasma and cerebrospinal fluid were observed between the p
atients with and without symptomatic vasospasm.
Conclusion: The increase of cerebrospinal fluid nitrate after SAH may attri
bute to the endogenous nitric oxide production in the injured brain.