Modern Technologies in Neuroanesthesiology

S.V. Efremenko, S.V. Murashkin

Chief Clinical Hospital of the Ministry of Internal Affairs of the Russian Federation, Moscow, Russia

 

Specific Components of Neuroanesthesiology: Support of adequate cerebral blood flow, prevention and treatment of cerebral hypoxic lesions, prevention of secondary intracranial hemorrhages, prevention and treatment of brain edema.

General Components of Neuroanesthesiology: Anesthesia, analgesia, neurovegetative protection, support of adequate blood circulation, support of adequate gas exchange and ventilation.

The Most Dangerous and Possible Complications of Induction Anesthesia: Edema and brain dislocation with development of decompensated circulation in the brain stem and brain herniation at different levels; hypoxia with development of secondary ischemic lesions of the brain; uncontrolled arterial hypotension and development of secondary ischemic lesions of the brain, uncontrolled arterial hypertension and development of secondary intracranial hemorrhages; vomiting and aspiration.

Prevention of Complication at the Stage of Preoperative Preparation and Induction Anesthesia: Preoperative correction of intracranial pressure (ICP) - mannitol; replacement of a circulating blood volume and normovolemia support - starch, glucose, etc. (no sodium-containing solutions); anemia correction; neurovegetative protection - lidocaine, opiates; adequate oxygenation - intubation and artificial respiration at the stage of preoperative preparation in case of coma and a score of less than 8 (Glasgow Coma Scale); correction of fluid-and-electrolyte balance; stomach drainage (it is compulsory in patients with consciousness disorders or in urgent operations).

Monitoring and Manipulations at the Stage of Preoperative Preparation and Induction Anesthesia: Central hemodynamics; catheterization of a central vein; central venous pressure; rectal (esophageal) temperature; artery catheterization; control of gas content and acid-base balance in an artery of vein in patients with consciousness disorders or associated injuries; urinary bladder catheterization; stomach drainage in urgent operations; hygiene of an oral cavity and sanative bronchoscopy in patients with traumas of facial skeleton and cases, who are admitted with suspected aspiration into the lungs.

Anesthesia Induction

Analgesia/Anesthesia. Low-flow anesthesia (LFA): Isofluraine + I/V phentanyl, no myorelaxants (only in case of performing operations in a craniocerebral area). Tendency to tachycardia, arterial hypertension, changes of compliance and resistance of pulmonary tissue are indications for using phentanyl. A general course of anesthesia: 0.7-1 volumetric% of isofluraine and LFA=0.5-1; 0.005% phentanyl - 6-10 mg/kg/h. We do not use N20, myorelaxants and thiopental for anesthesia support.

Correction of Intracranial Pressure. Mannitol (0.5-1 g/kg) is used at the stage of preoperative preparation. It is administered intravenously and continuously at a speed of 0.1 g/kg/h during anesthesia support (for prevention of rebound syndrome). If necessary, a speed of administration can be increased. Hyperventilation lasts not more than 15 min (up to pCO2 of 28 mm Hg).

Artificial Respiration. The optimum mode of artificial respiration in neuroanesthesia is PCV. It allows to prevent sudden (prolonged and single-moment) growth of intrathoracic pressure with increase of ICP. Normocapnia is ensured (pCO2 of not less than 30 mm Hg). Compulsory monitoring of compliance and resistance of pulmonary tissue is carried out.

Anesthesia Completion. Transportation to an intensive care unit against a background of continuous artificial respiration (a portable device for artificial pulmonary ventilation). Transfer to independent breathing after restoration of esophageal (rectal) temperature up to 37o C.