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Noninvasive measurement of intracranial pressure via the pulsatility index on transcranial doppler sonography: Is improvement possible?
Author(s) -
Morgalla Matthias H.,
Magunia Harry
Publication year - 2016
Publication title -
journal of clinical ultrasound
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.272
H-Index - 61
eISSN - 1097-0096
pISSN - 0091-2751
DOI - 10.1002/jcu.22279
Subject(s) - medicine , transcranial doppler , hemodynamics , middle cerebral artery , intracranial pressure , blood pressure , cardiology , hematocrit , mean arterial pressure , pulsatility index , anesthesia , heart rate , ischemia , pregnancy , fetus , biology , genetics
Purpose We hypothesized that using hemodynamic variables could improve the prediction of intracranial pressure (ICP) from the middle cerebral artery pulsatility index (PI) measured with transcranial Doppler sonography. Methods In this prospective study, 39 patients with traumatic brain injury were routinely examined with transcranial Doppler sonography, and the middle cerebral artery PI was calculated. A multivariate model including hematocrit, mean arterial blood pressure, heart rate, and arterial CO 2 pressure (P a CO 2 ) was evaluated. Results Thirty‐nine comatose patients (16 women and 23 men; age range 18–73 years; median 44 years) were included, and 234 data pairs (consisting of ICP and corresponding PI values) were analyzed. ICP ranged from −3 mmHg to +52 mmHg, and PI from 0.6 to 2.85. We found a significant but weak correlation between PI and the square root of ICP ( R 2 between 0.29 and 0.34, p < 0.0001). A slightly stronger correlation was detected when hemodynamic variables were incorporated ( R 2 between 0.37 and 0.43). Of these variables, mean arterial blood pressure had the most significant influence. Conclusions In this study, PI was not a sufficiently strong predictor of ICP to be used in clinical practice. Its reliability did not improve even when hemodynamic variables were considered. Therefore, we recommend abandoning the use of PI for the noninvasive measurement of ICP in clinical practice. © 2015 Wiley Periodicals, Inc. J Clin Ultrasound 44 :40–45, 2016