Skeletal Muscle Relaxants and Their Impact on Intracranial Pressure in Neurosurgery

Abstract

Skeletal muscle relaxants have their place in everyday use in numerous anesthesiological procedures, such as preparing a patient for surgery, supporting mechanical ventilation, and performing effective intubation. These drugs can be divided, based on their mechanism of action, into depolarizing skeletal relaxants, such as succinylcholine, and non-depolarizing skeletal muscle relaxants. Non-depolarizing agents are further categorized, based on their structure, into steroidal (eg, rocuronium) and benzylisoquinoline (eg, atracurium) compounds. To gain better control over neuromuscular blockade and patient recovery, a group of drugs known as reversal agents was developed. The effectiveness of skeletal muscle relaxants can be influenced by factors such as acid-base imbalances, impaired metabolism, and excretion, due to kidney or liver dysfunction, age, and sex. Skeletal muscle relaxants have also been used in neurosurgical procedures. It is believed that these drugs do not cross the blood-brain barrier. By reducing intrathoracic pressure and central venous pressure, they can lower intracranial pressure. However, in some studies, an increase in intracranial pressure has been observed. Therefore, selecting the appropriate drug is crucial, particularly for patients with suspected or confirmed elevated intracranial pressure, which is defined as the pressure within the intracranial space relative to atmospheric pressure. Elevated intracranial pressure above normal levels can occur in various conditions, such as sinus thrombosis, aneurysm rupture, brain tumors, intraventricular hemorrhage, and meningitis. In this article, we aim to review the role of muscle relaxants and reversal agents in neurosurgical procedures.