Premium
The effect of magnesium sulphate on blood flow velocity in the maternal retina in mild pre‐eclampsia: a preliminary colour flow Doppler study
Author(s) -
BELFORT M. A.
Publication year - 1992
Publication title -
bjog: an international journal of obstetrics and gynaecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.157
H-Index - 164
eISSN - 1471-0528
pISSN - 1470-0328
DOI - 10.1111/j.1471-0528.1992.tb13846.x
Subject(s) - medicine , eclampsia , blood flow , central retinal artery , hemodynamics , magnesium , ophthalmic artery , ultrasound , anesthesia , cardiology , chemistry , pregnancy , biology , radiology , genetics , organic chemistry
Objectives To investigate the use of colour flow Doppler ultrasound to identify retinal blood vessels in women with mild pre‐eclampsia and to assess the effects of an infusion of magnesium sulphate on the baseline retinal blood flow‐velocity. Design Prospective descriptive study. Setting Ben Taub Hospital, Baylor College of Medicine, Houston, Texas, USA. Subjects Eight women with mild pre‐eclampsia Interventions Baseline colour flow Doppler ultrasound assessment of the central retinal artery (CRA) and posterior ciliary artery (PCA) blood flow‐velocity before intravenous infusion of 6 g of magnesium sulphate in 100 ml of 5% dextrose water over 20 min, followed by repeat Doppler measurement. Main Outcome Measures Blood pressure, heart rate, pulsatility index (PI), resistance index (RI), angle‐corrected flow‐velocity (cm/s). Results The CRA and PCA were easily and reliably identified. The infusion of 6 g of magnesium sulphate significantly reduced ( P<0.05 ) the mean CRA PI from 1.42 (SD 0.67) to 0.93 (SD 0.18) and the mean CRA RI ( P < 0.008 ) from 0.62 (SD 0.07) to 0.53 (SD 0.10). The PCA PI decreased ( P = 0.01 ) from 0.97 SD (0.14) to 0.78 SD (0.18) and the PCA RI decreased ( P = 0.02 ) from 0.58 SD (0.07) to 0.48 SD (0.09). Angle‐corrected flow‐velocity decreased non‐significantly after the magnesium sulphate infusion. Conclusions Patients with pre‐eclampsia have high CRA and PCA flow‐velocity suggestive of vasospasm. Magnesium sulphate acutely vasodilates the small arteries in the retina, increasing retinal blood flow. Changes in the blood flow in the retina may be indicative of similar changes in other end‐arterial branches of the internal carotid artery. This non‐invasive Doppler method may provide a means to monitor the effects of therapeutic interventions in patients with pre‐eclampsia.