Introduction: Mannitol is commonly used in neurosurgical units to reduce intracranial pressure.
It has effects on both cardiovascular and cerebral hemodynamics. The temporal sequence
of cardiovascular and cerebrovascular effects of mannitol has not been studied. This
study assesses the hemodynamic and cerebrovascular changes using combined transthoracic
and transesophageal echo after administration of mannitol in postoperative neurosurgical
patients. Methods: The study was approved by ethics committee. Adult patients who were admitted in neurosurgical
ICUs for surgical removal of intracranial tumors were included in the study. TCD and
TTE findings were recorded on day 1 and day 2 following administration of 0.5 g/kg
of mannitol. Comparison was made between operated and non operated side. Appropriate
statistical analysis was done to assess the effects of mannitol on cardiovascular
and mean flow velocity in middle cerebral artery blood flow. Results: HR, MAP, SPO2 showed no change after mannitol use. Mean flow velocity increased in
both operated and non operated side but more in non operated side. Pulsatality index
decreased from baseline but was not statistically significant. Resistance index also
did not decrease in both sides. The estimated CPP was significantly increased at 5
mins on operated side upto 15 mins post mannitol use. There was no significant change
in mean flow velocity, pulsatality index and resistance index ICP on second day. The
ECHO variables like left ventricular dimensions, stroke volume and cardiac output
did not change significantly following mannitol infusion. Conclusion: Adminstration of 0.5 g/kg of mannitol in immediate postoperative period was associated
with increase in the mean flow velocity without change in cardiovascular variables.
However the cerebrovascular effects was not seen significant change from baseline
on second postoperative day. Our result may have an impact on the management of these
patients in the neurocritical care.
