Bispectral Index Value Changes During Induction and Surgical Decompression in Head Injury Patients

This study was conducted in two parts: This first part was designed to determine thiopentone dose requirement for induction of anaesthesia with and without the use of Bispectral Index monitoring - Participant and Care Provider in appropriate study arm blinded. As a secondary outcome, Bispectral index monitoring was used to observe changes in neuronal function in intraoperative period as well as haemodynamic changes intraoperatively - Participant and Care Provider blinded.

Surgery for traumatic brain injury is an anaesthetic challenge fraught with complications such as brain bulge, excessive bleeding, hypotension etc. As yet there are no anaesthetic regimen guidelines to follow for induction of anaesthesia in neurotrauma surgeries. Although the functional effect of anaesthetic agents on neuronal tissue is known quite well, there is lack of studies documenting the effect of these anaesthetic agents on head injured patients. It is also not known whether the requirement of anaesthetic agent in the same as a non head injured patient. This study was designed to assess the requirement of anaesthetic thiopentone in head injured patients and compare the anaesthetic usage with and without Bispectral index (BIS) monitoring. We also observed the real time change in neuronal function using Bispectral Index monitoring after craniotomy, i.e. effectively decompression and release of intracranial pressure intraoperatively.

Inj. Thiopentone dose requirement for induction of anaesthesia with and without the use of Bispectral Index guidance. Observation of Bispectral Index change in intraoperative period.

Anaesthetic care provider in one arm of first part of study was blinded to intraoperative changes in Bispectral index. Anaesthetic care provider was blinded to Bispectral Index changes in second part of study.

Thiopentone dosing during induction of anaesthesia based on clinical guidance targeted to loss of eyelash reflex or loss of response to noxious stimulus.

Thiopentone was administered in 50 mg boluses during induction of anaesthesia, until reduction of Bispectral Index value to less than 50, and total dose of thiopentone recorded.

Difference of thiopentone requirement with and without use of Bispectral Index guidance during induction of anaesthesia in traumatic brain injury patients.

Inclusion Criteria: Head injury patients coming for surgery Exclusion Criteria: Hypotension/Arrythmias at time of induction Extra Dural Hemorrhage Extracranial injuries Scalp lacerations History of Seizures No consent