Overview

Anesthesia for cranial surgeries is charactarized by periods of unpleasant stimuli interspersed with periods of low stimulation, which may compromise hemodynamic regulation.

Intraoperative and early postoperative episodes of hypertension during moments of strong stimulation can cause major consequences such as post craniotomy intracranial haemorrhage and vasogenic brain edema.

The use of powerful opioid analgesics like fentanyl and remifentanil in increasing doses for anaesthesia is a common practice among anesthesiologists.However, using strong opioids continuously or in bolus doses during surgery may result in postoperative hyperalgesia and higher analgesic need.

More recently, concerns have risen about impaired healing, immunosuppression , worsening of oncologic outcomes with systemic opioids and may affect conscious level at time of extubation (3).

Opioid-free anaesthesia(OFA) is increasingly gaining acceptance among anaesthesioligists. Its mainstay is based on a number of analgesic adjuvants that, when combined in small dosages, will produce effective anaesthesia with fewer side effects and a quicker recovery time than opioids. This approach, which combines several medications including dexmedetomidine, lidocaine, ketamine, ketorolac, and magnesium, has been used successfully in anaesthesia for bariatric procedures (3) . In cranial surgerie,OFA has been mainly used in pilot studies and case reports and their main focus was postoperative opioid consumption and not intraoperative haemodynamics.(4).

Dexmedetomidine which is a highly selective 2-adrenoceptor agonist has positive effects as anesthetic adjuvant.It has sedative, anxiolytic, and analgesic effects with little impact on respiratory drive, Dexmedetomidine analgesic properties are less potent than opioids, despite the fact that preoperative intravenous dexmedetomidine administration is linked to a reduction in postoperative pain intensity, analgesic intake, and nausea.

According to reports, intravenous lidocaine possesses analgesic, anti-hyperalgesic, and anti-inflammatory actions by inhibition of the priming of resting neutrophilic granulocytes which may reduce the liberation of superoxide anions a common pathway of inflammation. It has potentials for brain protections as it reduces cerebral oxygen consumption, cerebral blood volume and flow .Moreover ,it decreases the intracranial pressure and consequently results in brain relaxation.

The addition of a scalp block to general anaesthetic during craniotomies might lessen the discomfort associated with scalp incision and pin application, as well as the need for analgesics such as opioids or anaesthesia adjuvants, encouraging early recovery for neurological evaluation. The usage of this block has increased as a result of recent developments in neurosurgery, particularly awake craniotomy.

To our knowledge ,the effects of continuous intravenous lidocaine and dexmedetomidine infusion on hemodynamics, brain relaxation and surgeon satisfaction in adult patients undergoing cranial surgeries for tumor excision without the use of opioids, however, have not been studied.

Eligibility

Inclusion Criteria:

1. ASA Ι and II.
2. Patients undergoing resection of supratentorial tumors in supine position.
3. Age (18-50) years.
4. Both sexes.

Exclusion Criteria:

1. Impaired renal functions.
2. Uncontrolled systemic hypertension(patients with sustained elevated blood pressure more than 140/90).
3. Cardiac arrhythmias (any rhythm other than normal sinus rhythm and sinus tachycardia).
4. Heart failure(impaired cardiac contractility ,EF less than 45%.).
5. Patients receiving more than 2 units of blood during surgery.
6. Patients with large masses and expected severe increase in ICP.
7. Patients requiring vasopressors infusion.
8. The need for postoperative ventilation at the end of study.
9. Glasgow coma scale less than 14.
10. History of allergy to the study drugs.
11. Surgeries lasting more than 4 hours.
12. Pregnancy.
13. Bronchial asthma.