Evaluation of intravenous infusion of labetalol versus magnesium sulfate on cerebral hemodynamics of preeclampsia patients with severe features using transcranial doppler

PURPOSE: It is essential to understand the underlying pathophysiological mechanisms of preeclampsia cerebral complications. This study aimed to compare the cerebral hemodynamic effects of magnesium sulfate (MgSO4) and labetalol in pre-eclampsia patients with severe features. METHODS: Singleton pregnant women who suffered from late onset preeclampsia with severe features were enrolled and subjected to baseline Transcranial doppler (TCD) evaluation and then randomly assigned to either the magnesium sulfate group or labetalol group. TCD to measure middle cerebral artery (MCA) blood flow indices including mean flow velocity (cm/s), mean end-diastolic velocity (DIAS), and pulsatility index (PI) and to estimate CPP and MCA velocity were performed as basal measurements before study drug administration and at post-treatment one and six hours after administration. The occurrence of seizures and any adverse effects were recorded for each group. RESULTS: Sixty preeclampsia patients with severe features were included and randomly allocated into two equal groups. In group M the PI was 0.77 ± 0.04 at baseline versus 0.66 ± 0.05 at 1hour and 0.66 ± 0.05 at 6 hours after MgSO4 administration (p value < 0.001) also the calculated CPP was significantly decreased from 103.3 ± 12.7mmHg to 87.8 ± 10.6mmHg and 89.8 ± 10.9mmHg (p value < 0.001) at 1 and 6 hours respectively. Similarly, in group L the PI was significantly decreased from 0.77 ± 0.05 at baseline to 0.67 ± 0.05 and 0.67 ± 0.06 at 1 and 6 hours (p value < 0.001) after labetalol administration. Moreover, the calculated CPP was significantly decreased from 103.6 ± 12.6 mmHg to 86.2 ± 13.02mmHg at 1 hour and to 83.7 ± 14.6mmHg at 6 hours (p value < 0.001). In terms of changes in blood pressure and the heart rate, they were significantly lower in the labetalol group. CONCLUSION: Both magnesium sulfate and labetalol reduce CPP while maintaining cerebral blood flow (CBF) in preeclampsia patients with severe features. TRIAL REGISTRATION: The institutional review board of the Faculty of Medicine, Zagazig University approved this study with the reference number (ZU-IRB#: 6353-23-3-2020) and it was registered at clinicaltrials.gov (NCT04539379).