Overnight Shunt Pressure Monitoring in Children

Abstract

We audited the value of overnight shunt pressure monitoring in 17 children with symptoms of possible shunt dysfunction but no other supportive evidence. The shunt was accessed by a 25G butterfly connected to a disposable arterial pressure monitor positioned on the ipsilateral shoulder whose output was recorded continuously, while noting posture, sleep state and symptoms. Initially traces were analysed only for the portion spent both asleep and supine or prone. Six showed pressure peaks while asleep: of these four underwent shunt revision with remission of their symptoms and two resolved spontaneously, one with a simultaneous resolution of a peritoneal CSF collection, but the other had a recurrence of symptoms after six months. Two more subsequently shown to have blocked shunts had normal traces while asleep but abnormal pressure peaks when awake and upright. Two showed pressure troughs: one responded to insertion of an antisyphon device and one resolved spontaneously. Five had normal traces while asleep and awake: symptoms resolved in three and persisted in two in whom later prolonged extradural monitoring with a fibre-optic transducer was also normal. Studies failed in two. We conclude that prolonged overnight shunt pressure monitoring with this technique is useful in diagnosing shunt dysfunction and that abnormalities detected while awake and upright are as significant as those detected asleep and supine or prone.

Key words

Hydrocephalus - Children - Shunt dysfunction - Monitoring (OICM)