Zero drift of intraventricular and subdural intracranial pressure monitoring systems

Abstract

【Abstract】Objective: To assess zero drift of intra-ventricular and subdural intracranial pressure (ICP) moni-toring systems. Methods: A prospective study was conducted in pa-tients who received Codman ICP monitoring in the neuro-surgical department from January 2010 to December 2011. According to the location of sensors, the patients were ca-tegorized into two groups: intraventricular group and sub-dural group. Zero drift between the two groups and its as-sociation with the duration of ICP monitor were analyzed. Results: Totally, 22 patients undergoing intraven-tricular ICP monitoring and 27 receiving subdural ICP moni-toring were enrolled. There was no significant difference in duration of ICP monitoring, zero drift value and its absolute value between intraventricular and subdural groups (5.38 d± 2.58 d vs 4.58 d±2.24 d, 0.77 mm Hg±2.18 mm Hg vs 1.03 mm Hg± 2.06 mm Hg, 1.68 mm Hg±1.55 mm Hg vs 1.70 mm Hg±1.53 mm Hg, respectively; all P>0.05). Absolute value of zero drift in both groups significantly rose with the increased duration of ICP monitoring (P<0.05) while zero drift value did not. Moreover, daily absolute value in the intraventricular group was sig-nificantly smaller than that in the subdural group (0.27 mm Hg± 0.32 mm Hg vs 0.29 mm Hg±0.18 mm Hg, P<0.05). Conclusion: This study demonstrates that absolute value of zero drift significantly correlates with duration of both intraventricular and subdural ICP monitoring. Due to the smaller daily absolute value, ICP values recorded from intraventricular system may be more reliable than those from subdural system. Key words: Intracranial pressure; Equipment failure; Cerebral ventricles; Subdural space