Ultrasound-guided neural blockade in Proteus syndrome

Abstract

Summary: Proteus syndrome is a rare genetic disorder first described in 1979 and named after Proteus, a Greek demigod who was capable of changing his form to avoid capture. The incidence is < 1:1 000 000, but can be expected to be slightly higher in the surgical population, as these patients often present for repeat procedures. The disorder is characterised by sporadic and progressive overgrowth of tissue of any origin. Normal anatomy usually becomes distorted and serious functional and cosmetic sequelae may ensue. Regular anaesthetic interventions are required for diagnostic and therapeutic procedures, often to correct deformities related to overgrowth, tumour excision and otolaryngological procedures. Literature relating to the anaesthetic management of patients with Proteus syndrome is limited to case reports describing instances of general anaesthesia. Complications of general anaesthesia secondary to respiratory tract abnormalities appear prevalent. Regional anaesthesia is often used when respiratory compromise is anticipated due to any cause. Despite this, current guidelines suggest that regional anaesthesia be avoided in patients with Proteus syndrome, due to the gross anatomical variance and the high incidence of vascular abnormalities in these patients. The use of ultrasound-guided neural block enables practitioners to distinguish nerves from vascular structures and other tissues. It helps avoid neural injury during needle placement and improves success rate. This case report is the first to demonstrate the successful use of an ultrasound-guided regional anaesthetic technique in a boy requiring surgery to his right forearm.

Keywords: anaesthesia, local, nerve block, Proteus syndrome, ultrasound