Article
Can a noninvasive device using transcranial acoustic signals replace established invasive methods for measuring ICP?
Können transkranielle akustische Signale als nichtinvasives Verfahren die etablierten invasiven Methoden zur Hirndruckmessung ersetzen?
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Authors
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David Butter
- Bundeswehrkrankenhaus Berlin, Neurochirurgie, Berlin, Deutschland
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Niklas Rohwedder
- Bundeswehrkrankenhaus Ulm, Neurochirurgie, Ulm, Deutschland
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Uwe Max Mauer
- BwKrhs Ulm, Neurochirurgie, Ulm, Deutschland
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Simon Mayer
- BwKrhs Ulm, Neurochirurgie, Ulm, Deutschland
| Published: | May 8, 2019 |
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Outline
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Objective: Up till now there is no established method for measuring ICP (intracranial pressure) in a noninvasive approach. The only reliable way to measure ICP is by inserting a probe in an invasive procedure. Like every surgery, this procedure is associated with a certain risk of infection and bleeding, amongst others. The company HeadSense has developed a device which is considered to be able to measure ICP in a noninvasive manner using transcranial acoustic signals. In this study the accuracy of the HS-1000 device was assessed using intraparenchymal monitoring and external ventricular drainage (EVD) as reference to answer the question if the HS-1000 device can replace invasive methods for measuring ICP in daily routine.
Methods: ICP was measured simultaneously in patients with ongoing invasive ICP measurement using EVD or intraparenchymal probe (telemetric or with cable) and the HS-1000. The time and sessions of measurement were limited by the patient’s compliance. Data were analysed using IBM SPSS 24 for calculating bias, 95% limits of agreement and percentage of paired measurements with absolute difference between invasive and noninvasive ICP ±5 mm Hg, amongst other factors.
Results: 14 patients were recruited to participate in this study. The most frequent reason for ongoing invasive ICP measurement was suspected normal pressure hydrocephalus (n=11). In most patients ICP was measured by an intraparenchymal probe (n=12, of which 10 have been with cable and 2 telemetric) and in 2 patients by EVD. In total 5540 paired measurements were obtained. The average of paired measurements per patient was 424.5 (minimum 76, maximum 1059). The bias was 7.27 mm Hg. The 95% limits of agreement were 20.93 mm Hg and -6.38 mm Hg. A difference of ±5 mm Hg between the invasive and noninvasive measurement were observed in 31.80% (1762/5540) of all paired measurements.
Conclusion: The findings in this study show a major difference between the invasive ICP measurements used as a reference for true ICP and noninvasive ICP measurements using the HS-1000. The calculated 95% limits of agreement are clinically relevant. To our opinion the HS-1000 cannot replace the established invasive methods for measuring ICP in daily routine.
