Monitoring intracranial pressure (ICP) is critical in patients at risk of raised ICP. Intraventricular pressure (IVP) monitoring is still the gold standard in the clinical setting due to its reliability and accuracy over epidural (ED) or subdural (SD) ICP monitoring. However, ED and SD monitoring can be beneficial in reducing the risk of infection and bleeding associated with IVP monitoring. Therefore, we evaluated the reliability of SD ICP monitoring in preclinical stroke models by comparing it against IVP and ED ICP monitoring methods at different ICP levels over time. Male Wistar rats (250-350g) were anaesthetised using isoflurane (5% induction, 1.5-2% maintenance) in 50:50 N2:O2. The rats were subjected to either middle cerebral artery occlusion or photothrombotic stroke, and ICP was measured from 18-24hrs post-stroke. Briefly, a burr hole (2mm posterior, 2mm lateral to Bregma) was drilled in the right parietal bone and the dura was gently pierced using an atraumatic Sprotte-type needle. A fibre optic pressure sensor probe (Opsens, Canada) was inserted through the burr hole to access the epidural space. Another burr hole in the left parietal bone (0.8mm posterior, 1.8mm lateral to Bregma) was made, and a second ICP probe was either inserted into the left lateral ventricle for IVP monitoring or into the epidural space (dura intact) for ED ICP monitoring. The probes were sealed and either IVP (n=99) or ED ICP (n=107) was measured simultaneously with SD ICP in real-time. Values are mean ± SD. The Pearson correlation coefficients of the mean intraventricular-subdural and epidural-subdural ICP values were r = 0.91 (p<0.0001) and r = 0.95 (p<0.0001), respectively. Using the Bland-Altman analysis, intraventricular-subdural and epidural-subdural methods showed a mean difference of 0.15 ± 2.1 mmHg and 0.16 ± 1.7 mmHg respectively. ICP measured using the modified SD method was reliable and reproducible, and was comparable to data obtained from both the ‘gold-standard’ IVP method and the ED ICP method. The results suggest that SD method is a valid alternative to the more invasive IVP monitoring, as well as the ED ICP method.
Europhysiology 2018 (London, UK) (2018) Proc Physiol Soc 41, PCB342
Poster Communications: Assessment of the reliability of subdural intracranial pressure measurement method in preclinical ischaemic stroke models
A. Patabendige1,2, N. MacKovski1, R. Hood1, N. J. Spratt1,2,3
1. School of Biomedical Sciences & Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia. 2. Hunter Medical Research Institute, Newcastle, New South Wales, Australia. 3. Neurology, John Hunter Hospital, Newcastle, New South Wales, Australia.
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Where applicable, experiments conform with Society ethical requirements.