Rebleeding.
Rebleeding is one of the most feared complications and is usually manifest as deterioration in neurological state. If rupture occurs during anaesthesia, the patient can develop dysrhythmias and brain swelling. If a ruptured aneurysm is not treated, there is a 40% chance of rebleeding in the first 28 days. Approximately 70% of patients who suffer a second bleed will die.
High transmural pressure ( Transmural pressure = Intravascular pressure- Extravascular pressure ) will predispose to rupture of an aneurysm. To prevent rebleeding it’s important to prevent pressure surges especially at the time of laryngoscopy and intubation. Aim was to maintain trans mural pressure gradient.
Cerebral ischemia or Infarction
It can occur immediately
…show more content…
Comparatively, Halothane will increase CBF. Theoretically due to the known drawbacks of N2O increases ICP, especially when it is used in conjunction with volatile agents, and it can inactivate Vitamin B-12 in prolonged use. air was use instead of N2O.
Clinically, both Enflurane and Isoflurane have weaker cerebrovasodilatory actions than Halothane, but Isoflurane is preferred because of Enflurane’s potential adverse proconvulsant action and adverse effects on CSF dynamics. Hyperventilation attenuates or prevents the cerebral blood flow, enhancing effects of potent inhalation anaesthetics. When PaCO2 is rapidly reduced, CBF decreases faster with Isoflurane than with Halothane.
Potent inhaled agents reduce CMRO2 by 20-30% at clinically encountered doses. Transmural aneurysm pressure is thought to determine the likelihood of rebleeding. So elevation of systemic arterial blood pressure or reduction of ICP might cause rupture of the aneurysm. We maintained an adequate depth of anaesthesia with Isoflurane. Mannitol was given with the first Burr hole to prevent increase of transmural pressure.