The principles of, and indications for ICP monitoring are discussed with the physiology of intracranial pressure . The most accurate and reliable method of monitoring intracranial pressure is with an intraventricular catheter connected to a pressure transducer. Manometer type systems allow re-calibration whereas fibreoptic devices may suffer from baseline drift if used for several days. Catheters may also be placed in the cerebral parenchyma, or the subdural and subarachnoid spaces. While easier to insert in some cases these may not accurately measure the ICP when compared to an intraventricular catheter.
Epidural devices are significantly less accurate.
In general complications related to ICP monitoring are rare. The greatest concern, ventriculitis, has never been demonstrated in prospective studies of clinically significant intracranial infections following ICP measurement. Irrigating ICP devices significantly increases the risk of colonisation. Treatment is removal of the ICP bolt. Parenchymal catheters have a higher incidence of haematoma than other methods.