Prospective study of methodological issues in intracranial pressure monitoring in patients with hydrocephalus

Restricted access

Object

Continuous intracranial pressure (ICP) monitoring is performed in selected patients with hydrocephalus to determine whether shunt placement is required. The mean ICP is usually calculated from end-hour readings manually recorded by nurses. The aim of this study was to evaluate the accuracy of manual recordings by comparing nurses' end-hour ICP readings with those of an online computerized ICP monitoring system that records one ICP value per second.

Methods

Continuous ICP monitoring was performed using a fiberoptic extradural sensor in 115 patients with hydrocephalus of different origins. A notebook computer was connected to an ICP monitor and was programmed to register one ICP value per second. In all patients, mean ICP values were calculated from data recorded manually by nurses at the end of every hour and from data recorded by the computer within the preselected time period. The two methods were compared using correlation analysis and the Bland and Altman method.

The median number of ICP values noted manually by the nurses in each patient was 17 (interquartile range 15–18 readings), and that recorded by the software was 61,200 (interquartile range 54,000–64,800 readings). The correlation coefficient of the mean ICP values recorded by both methods was r = 0.99 (p < 0.001). The Bland and Altman analysis revealed a mean difference of 0.3 ± 1.26 mm Hg between the two methods and that they were equally valid with all mean ICP values.

Conclusions

The recording of end-hour ICP values by nurses is an accurate method of calculating the mean ICP after prolonged ICP monitoring in patients with hydrocephalus.

Article Information

Address reprint requests to: Maria A. Poca, M.D., Ph.D., Ferran Puig 70–72, 1–2, 08023 Barcelona, Spain. email: 26382app@comb.es.

© AANS, except where prohibited by US copyright law.

Headings

Figures

  • View in gallery

    Copy of nurses' manual end-hour ICP recording chart. Gray boxes correspond to the diurnal monitoring period; white boxes correspond to the nocturnal monitoring period.

  • View in gallery

    Tracings showing examples of ICP waves in patients included in this study. Upper: A waves in which the plateau reaches 100 mm Hg. Center: High-amplitude B waves in which ICP readings can reach more than 40 mm Hg. Lower: Low-amplitude B waves in which the mean ICP is always less than 10 mm Hg.

  • View in gallery

    Schematic drawing of all the elements involved in ICP monitoring of patients included in this study. A: Notebook personal computer. B: Nurses' chart for manual ICP recording. C: Graph paper recording.

  • View in gallery

    Chart showing an example of numerical and graphic ICP data obtained with the computerized system connected to the ICP monitor.

  • View in gallery

    Histogram of differences in mean ICP values recorded by manual and computerized methods. The median difference in the mean ICP values recorded by both methods was 0 mm Hg, with a maximum and minimum difference of 5 and −4 mm Hg, respectively, and an interquartile range of 0 and 1 mm Hg.

  • View in gallery

    Graph showing correlation of mean ICP values calculated by the computer software and mean ICP values calculated manually with nurses' end-hour ICP readings (Spearman rank correlation analysis).

  • View in gallery

    Scatterplot showing analysis of agreement with the Bland and Altman method. The difference between the methods (y axis) is plotted against their mean (x axis). The mean difference between the two methods is 0.296 ± 1.256 mm Hg. As can be seen, because their scattering did not vary over the range of mean ICP values, both methods are equally valid throughout the entire range of values.

References

  • 1.

    Arribas Ferrano MBosch Raventós SFontán Caudevilla C: Traumatismos craneoencefalicos graves. Variabilidad de la presión intracraneal y de la presión de la perfusión cerebral en relación con la posición de la cabeza y con la aspiración de secreciones. Emergencias 4:89941992Arribas Ferrano M Bosch Raventós S Fontán Caudevilla C: Traumatismos craneoencefalicos graves. Variabilidad de la presión intracraneal y de la presión de la perfusión cerebral en relación con la posición de la cabeza y con la aspiración de secreciones. Emergencias 4:89–94 1992

  • 2.

    Bland JMAltman DG: Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1:3073101986Bland JM Altman DG: Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1:307–310 1986

  • 3.

    Bullock RChesnut RMClifton Get al: Guidelines for the management of severe head injury. Brain Trauma Foundation, American Association of Neurological Surgeons, Joint Section on Neurotrauma and Critical Care. J Neurotrauma 13:6417341996Bullock R Chesnut RM Clifton G et al: Guidelines for the management of severe head injury. Brain Trauma Foundation American Association of Neurological Surgeons Joint Section on Neurotrauma and Critical Care. J Neurotrauma 13:641–734 1996

  • 4.

    Bullock RMChesnut RMClifton GLet al: The Brain Trauma Foundation. The American Association of Neurological Surgeons. The Joint Section on Neurotrauma and Critical Care. Indications for intracranial pressure monitoring. J Neurotrauma 17:4975062000Bullock RM Chesnut RM Clifton GL et al: The Brain Trauma Foundation. The American Association of Neurological Surgeons. The Joint Section on Neurotrauma and Critical Care. Indications for intracranial pressure monitoring. J Neurotrauma 17:497–506 2000

  • 5.

    Fouyas IPCasey ATThompson Det al: Use of intracranial pressure monitoring in the management of childhood hydrocephalus and shunt-related problems. Neurosurgery 38:7267321996Fouyas IP Casey AT Thompson D et al: Use of intracranial pressure monitoring in the management of childhood hydrocephalus and shunt-related problems. Neurosurgery 38:726–732 1996

  • 6.

    Kopniczky ZBarzo PPavics Let al: Our policy in diagnosis and treatment of hydrocephalus. Childs Nerv Syst 11:1021061995Kopniczky Z Barzo P Pavics L et al: Our policy in diagnosis and treatment of hydrocephalus. Childs Nerv Syst 11:102–106 1995

  • 7.

    Lamas EEsparza JDiez Lobato R: Intracranial pressure in adult non-tumoral hydrocephalus. J Neurosurg Sci 19:2262331975Lamas E Esparza J Diez Lobato R: Intracranial pressure in adult non-tumoral hydrocephalus. J Neurosurg Sci 19:226–233 1975

  • 8.

    Lundberg N: Continuous recording and control of ventricular fluid pressure in neurosurgical practice. Acta Psychiatr Scand 36 (Suppl 149):11931960Lundberg N: Continuous recording and control of ventricular fluid pressure in neurosurgical practice. Acta Psychiatr Scand 36 (Suppl 149):1–193 1960

  • 9.

    Miller JD: ICP monitoring—current status and future directions. Acta Neurochir 85:80861987Miller JD: ICP monitoring—current status and future directions. Acta Neurochir 85:80–86 1987

  • 10.

    Mitchell PHMauss NK: Relationship of patient-nurse activity to intracranial pressure variations: a pilot study. Nurs Res 27:4101978Mitchell PH Mauss NK: Relationship of patient-nurse activity to intracranial pressure variations: a pilot study. Nurs Res 27:4–10 1978

  • 11.

    Mitchell PHOzuna JLipe HP: Moving the patient in bed: effects on intracranial pressure. Nurs Res 30:2122181981Mitchell PH Ozuna J Lipe HP: Moving the patient in bed: effects on intracranial pressure. Nurs Res 30:212–218 1981

  • 12.

    Poca MASahuquillo J: Inicaciones y aspectos practices en el estudio de la presión intracraneal y de la dinamica del LCR en pacientes con patologia neurologica. Neurologèa 16:3033202001Poca MA Sahuquillo J: Inicaciones y aspectos practices en el estudio de la presión intracraneal y de la dinamica del LCR en pacientes con patologia neurologica. Neurologèa 16:303–320 2001

  • 13.

    Poca MASahuquillo JBusto Met al: Clinical management of patients with normal pressure hydrocephalus syndrome. Ann Psychiatry 6:2732921996Poca MA Sahuquillo J Busto M et al: Clinical management of patients with normal pressure hydrocephalus syndrome. Ann Psychiatry 6:273–292 1996

  • 14.

    Poca MASahuquillo JMataro M: Actualizaciones en el diagnostico y tratamiento de la hidrocefalia “normotensiva” (hidrocefalia cronica del adulto). Neurología 16:3533692001Poca MA Sahuquillo J Mataro M: Actualizaciones en el diagnostico y tratamiento de la hidrocefalia “normotensiva” (hidrocefalia cronica del adulto). Neurología 16:353–369 2001

  • 15.

    Poca Pastor MASahuquillo Barris JIbañez Dominguez Jet al: Aplicación de la monitorización continua de la presión intracraneal al diagnóstico de la hidrocetefalia crónica del adulto. Introducción a la interpretación de registros gráficos in Vázquez-Barquero APoca Pastor MAMartín Láez R (eds): Hidrocefalia Crónica del Adulto. Santander-Cantabria: Gráficas Calima, S.A.2001 pp 69102Poca Pastor MA Sahuquillo Barris J Ibañez Dominguez J et al: Aplicación de la monitorización continua de la presión intracraneal al diagnóstico de la hidrocetefalia crónica del adulto. Introducción a la interpretación de registros gráficos in Vázquez-Barquero A Poca Pastor MA Martín Láez R (eds): Hidrocefalia Crónica del Adulto. Santander-Cantabria: Gráficas Calima S.A. 2001 pp 69–102

  • 16.

    Sahuquillo JBiestro AMena MPet al: Medidas de primer nivel en el tratamiento de la hipertension intracraneal in el patiente con un traumatismo craneoencefalico grave. Propuesta y justificacion de un protocolo. Neurocirugía 13:781002002Sahuquillo J Biestro A Mena MP et al: Medidas de primer nivel en el tratamiento de la hipertension intracraneal in el patiente con un traumatismo craneoencefalico grave. Propuesta y justificacion de un protocolo. Neurocirugía 13:78–100 2002

  • 17.

    Sahuquillo JPoca MARubio E: Monitorización de la preción intracraneal. Metodología e indicaciones en el patiente con patología neurológica aguda in Net AMarruecos L (eds): Neurología Crítica. Barcelona: Springer-Verlag1994 pp 5778 (Sp)Sahuquillo J Poca MA Rubio E: Monitorización de la preción intracraneal. Metodología e indicaciones en el patiente con patología neurológica aguda in Net A Marruecos L (eds): Neurología Crítica. Barcelona: Springer-Verlag 1994 pp 57–78 (Sp)

  • 18.

    Sahuquillo JRubio ECodina Aet al: Reappraisal of the intracranial pressure and cerebrospinal fluid dynamics in patients with the so-called “normal pressure hydrocephalus” syndrome. Acta Neurochir 112:50611991Sahuquillo J Rubio E Codina A et al: Reappraisal of the intracranial pressure and cerebrospinal fluid dynamics in patients with the so-called “normal pressure hydrocephalus” syndrome. Acta Neurochir 112:50–61 1991

  • 19.

    Turner HBAnderson RLWard JDet al: Comparison of nurse and computer recording of ICP in head injured patients. J Neurosci Nurs 20:2362391988Turner HB Anderson RL Ward JD et al: Comparison of nurse and computer recording of ICP in head injured patients. J Neurosci Nurs 20:236–239 1988

TrendMD

Metrics

Metrics

All Time Past Year Past 30 Days
Abstract Views 40 40 4
Full Text Views 89 89 0
PDF Downloads 61 61 1
EPUB Downloads 0 0 0

PubMed

Google Scholar