Continuous cerebral PtO2 measurements in awake patients as a diagnostic tool in suspected chronic adult hydrocephalus -: a retrospective study of 10 cases

Background. During the last decade of the 20th century, continuous invasive PtO2 recording has become a widely accepted and well-established means of monitoring patients with acute traumatic or spontaneous cerebral lesions. It is considered a safe and reliable tool for the detection of hypoxia in the ICU setting. However, while invasive measurements of intracranial pressure are being used both in the ICU and in standard diagnostic protocols for suspected chronic adult hydrocephalus the same has not yet happened in relation to PtO2 recordings. Methods. We report our experience with the first 10 patients who have been evaluated for suspected CAH applying a protocol that includes continuous cerebral PtO2 measurements. The relationship between PtO2 and ICP including a characteristic wave pattern (inverse waves) on the PtO2 curve is analyzed and clinical and outcome data are recorded. Results and conclusions. 1. PtO2 recording in awake patients is safe and reliable. 2. The combination of classical Lundberg waves in the ICP recording with phases of inverse waves in the PtO2 recording may predict good outcome after shunting. 3. The effect of concomitant conditions on the brain oxygenation can be estimated for individual patients and used as a negative predictor for surgical outcome. 4. Invasive intracranial monitoring is not free of potentially serious bleeding complications and can only be performed with risk enhancing factors (AVM/haemorrhagic diathesis) excluded.