Background: Patients with brain injury experience pathology of increased intracranial pressure (ICP), which is the cause of secondary brain injury, brain herniation at the risk of brain damage. Intracranial pressure control and monitoring is one of the most important strategies in managing patients in the neurosurgery and neurointensive care fields. Intracranial pressure monitoring in Dr. Soetomo General Hospital Surabaya is still limited by intraventricular catheter installation, which is invasive. The middle cerebral artery pulsatility index (PI) and sonographic optic nerve sheath diameter enable non-invasive monitoring of intracranial pressure. This study aimed to find out the correlation between middle cerebral artery pulsatility index and optic nerve sheath diameter with intracranial pressure.
Methods: Transcranial doppler measurement was made transtemporally to measure middle cerebral artery pulsatility index. Optic nerve sheath diameter was measured 3 mm behind the globe using 12 MHz US probe. Intracranial pressure was measured using intraventricular catheter. The correlation and regression between intracranial pressure, pulsatility index, and optic nerve sheath diameter were investigated.
Results: Thirty patients with various intracranial pathology, who underwent intraventricular catheter placement, were included in the study. A total of 86 intracranial pressure examinations, middle cerebral artery pulsatility index, and optic nerve sheath diameter were conducted. A significant correlation was found between pulsatility index and intracranial pressure with a correlation coefficient of 0.639; intracranial pressure = 9.23 x PI + 4 mmHg. Pulsatility index sensitivity was 93.2% with specificity 75.0%. Cut-off point was >1.11 for pulsatility index to detect increased intracranial pressure. The optic nerve sheath diameter and intracranial pressure correlation coefficient is 0.746; intracranial pressure = 7.88 x optic nerve sheath diameter – 26.84 mmHg with sensitivity 92.3% and specificity 95.83%. Optic nerve sheath diameter cut-off value was 5.4 mm.
Conclusion: There was a correlation between middle cerebral artery pulsatility index and optic nerve sheath diameter with intracranial pressure. Pulsatility index and optic nerve sheath diameter can be used as alternative for ICP monitoring.