ANAESTHESIA FOR SITTING CRANIOTOMY

Most explorations of the posterior cranial fossa can be performed with the patient in either a modified lateral or prone position, but the sitting position may be preferred by some surgeons because neurosurgery in the sitting position offers certain advantages. This position provides optimal surgical exposure for posterior fossa surgery because tissue retraction and risks of cranial nerve damage are reduced. Cerebrospinal fluid and cerebral venous drainage is enhanced by gravity producing a less tense brain which also improves surgical exposure and reduces blood loss. However, these advantages must be balanced against the risks which include high incidence of venous air embolism, paradoxical arterial air embolism, pneumocephalus, cerebral and myocardial ischaemia secondary to hypotension caused by venous pooling of blood in lower limbs. Other particular concerns to the anaesthesiologist are airway management, avoidance of pressure injuries, and the risk of upper airway edema, and rarely quadriplegia due to compression of the cervical spinal cord. Overall the benefits of the sitting position outweighs the risks if the patients are carefully selected and intraoperative management is conducted with care. We present a case of cerebellar space occupying lesion in which the excision was done in sitting position under general anaesthesia.