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  • Author or Editor: Dick C. J. Poortvliet x
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Joseph T. J. Tans and Dick C. J. Poortvliet

✓ Resistance to outflow of cerebrospinal fluid (Rcsf) was determined by constant flow infusions and pressure-volume index (PVI) using bolus infusions in 114 patients with various types of hydrocephalus. A clear correlation was found between PVI and Rcsf and, to a lesser degree, between these two parameters and baseline pressure. The PVI was not related to patient's age, duration of disease, type of hydrocephalus, or ventricular size, indicating that the relationship between PVI and Rcsf was genuine and not caused by patient selection. It is concluded that, in adult hydrocephalus, compliance is not an independent parameter but chiefly determined by Rcsf.

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Intracranial volume-pressure relationship in man

Part 1: Calculation of the pressure-volume index

Joseph Th. J. Tans and Dick C. J. Poortvliet

✓ The pressure-volume index (PVI) was determined in 40 patients who underwent continuous monitoring of ventricular fluid pressure. The PVI value was calculated using different mathematical models. From the differences between these values, it is concluded that a monoexponential relationship with a constant term provides the best approximation of the PVI.

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Intracranial volume-pressure relationship in man

Part 2: Clinical significance of the pressure-volume index

Joseph Th. J. Tans and Dick C. J. Poortvliet

✓ Pressure-volume indices (PVI's) were determined for a heterogeneous group of 40 patients who underwent continuous monitoring of ventricular fluid pressure (VFP). The main purpose was to investigate the relationship between VFP and PVI and to establish the significance of the measured PVI values. Determinations of PVI appear to be useful only when baseline VFP is under 20 mm Hg, maximum VFP is under 30 mm Hg, A-waves are absent, and B-waves do not occur numerously. The authors advocate starting with 1-ml bolus infusions, and then, when the resulting pressure rise exceeds 4 mm Hg, additional bolus infusions can be omitted. Results indicate that 13 ml and 10 ml are the key values for the PVI. A PVI of less than 13 ml indicates the need for either reduction of VFP and improvement of compliance or intensive monitoring of both the VFP and the volume-pressure relationship; if the PVI is below 10 ml, anti-hypertensive treatment is almost always necessary. Values of PVI's between 13 and 18 ml, although pathological, usually have no therapeutic consequences.