Optic Nerve Sheath Diameter in Pre-Eclamptic Parturient Receiving Magnesium Sulfate Combined With Dexmedetomidine

Benha University

Status: Completed

Conditions: Optic Nerve Sheath Diameter; Preeclampsia Severe

Treatments: Drug: Dexmedetomidine; Drug: Saline

Study type: Interventional

Funder types: Other

Identifiers

NCT05610774

RC 23.9.2022

Details and patient eligibility

About

Dexmedetomidine was reported to effectively reduce cerebral metabolism and ICP by decreasing cerebrospinal fluid pressure in patients with cerebral tumors or head injuries that require craniotomy. However, it was also reported to exhibit no effect on ICP. the effect of MgSO4 associated with dexmedetomidine on ONSD in severely pre-eclamptic parturient has been understudied . Though this study aims to evaluate the effect of dexmedetomidine infusion on raised ICP in severely pre-eclamptic parturients using ocular ultrasonography to determine ONSD as a measure of ICP.

Full description

Dexmedetomidine, a highly selective α-2-receptor agonist, is a first-line sedative medication in ICU and has been increasingly used for obstetric anesthesia. Dexmedetomidine, which provides light sedation, possesses analgesic, sympatholytic, anxiolytic properties and attenuates the stress response without significant respiratory depression. In addition, dexmedetomidine-induced stimulation of postsynaptic alpha-2 adrenergic receptor on the cerebral blood vessels can cause cerebral vasoconstriction and decrease cerebral blood flow. However, the effects of dexmedetomidine on ICP are controversial.

Clinical signs of raised ICP are not specific and often difficult to interpret, especially during pregnancy and pre-eclampsia. Though the use of invasive devices is considered a gold standard in the measurement of ICP, Ocular sonography is a promising bedside tool, which serves as a noninvasive, readily available, and cost-effective means for indirectly measuring ICP.

Bedside ultrasound can be used as a point-of-care tool for rapidly measuring the optic nerve sheath diameter (ONSD), which is a validated indirect means for measuring ICP. An increase in ICP reflects as a raised ONSD since the optic nerve is surrounded by Dural sheath and cerebrospinal fluid (CSF) containing subarachnoid space, which is distensible in the retrobulbar segment, particularly when CSF pressures rise.

Enrollment: 50 patients

Sex: Female

Ages: 18 to 40 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• aged18 to 40 years with
• at least 36 weeks gestation
• admitted with diagnosis of severe pre-eclampsia and scheduled to receive Magnesium Sulphate therapy before delivery

Exclusion criteria

• Presence of ocular wound or Prior ocular surgery
• emergency cases, and evidence of fetal compromise
• HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet levels)
• Chronic hypertension
• Hyperthyroidism, and diabetes mellitus
• Presence of pre-existing chronic lung and/or cardiac diseases
• Presence of pre-existing chronic renal and/or hepatic diseases
• Presence of any chronic diseases of central nervous system.
• known allergies to the tested drug.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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50 participants in 2 patient groups, including a placebo group

Group (D)

Experimental group

Description:

Patients will receive a loading dose of iv dexmedetomidine followed by a maintenance infusion.

Treatment:

Drug: Dexmedetomidine

Group (C)

Placebo Comparator group

Description:

patients will receive saline loading and infusion

Treatment:

Drug: Saline