Preventive Intramuscular Phenylephrine in Elective Cesarean Section Under Spinal Anesthesia

Xuzhou Medical University

Status: Completed

Conditions: Spinal Anesthesia; Elective Cesarean Section

Treatments: Drug: Normal saline; Drug: Phenylephrine; Drug: Bupivacaine

Study type: Interventional

Funder types: Other

Identifiers

NCT03507387

XYFY2018-KL010-01

Details and patient eligibility

About

Spinal anesthesia is the preferred anesthesia method in cesarean section to provide satisfactory analgesia and muscle relaxant with less impact on respiratory system. However, hypotension often occurred due to the block of sympathetic nerve, causing maternal decline of frontal lobe oxygenation, nausea vomit and the decrease of uteroplacental perfusion. Several measures are used to prevent or treat hypotension caused by spinal anesthesia: prehydration, limb compression, left lateral tilt of operation tables or usage of vasopressors. In the past decade, the most recommended vasopressor to prevent or treat hypotension in spinal anesthesia in cesarean section was phenylephrine, an α-adrenergic receptor, maintaining maternal blood pressure and fetal acid-base state. In clinical work, there are two ways to use phenylephrine : intravenous method with less onset time (several seconds and duration (several minutes) and intramuscular method with longer onset time (10-15 minutes) and duration (1 hour). Many trials demonstrated the protective effect of preventive intravenous phenylephrine on maternal hemodynamics and neonatal acid-base status. However, few trials reported the effect of preventive intramuscular phenylephrine on cesarean section under spinal anesthesia.

Full description

Hypotension often occurred in parturients undergoing cesarean section in spinal anesthesia. This study aims to determine whether preventive intramuscular phenylephrine can better the fetal acid-base state and maternal hemodynamics.

Enrollment: 99 patients

Sex: Female

Ages: 18 to 40 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. Age 18 years to 40 years.
2. Elective cesarean section
3. American Society of Anesthesiologists (ASA) grade from I to Ⅱ, height from 150 cm to 180 cm, BMI<40kg/m2
4. Singleton pregnancy
5. Without pregnancy complications

Exclusion criteria

1. Multiple pregnancy
2. Preoperative bradycardia
3. Coagulation dysfunction
4. Parturients with hypertension, diabetes, eclampsia and other pregnancy complications.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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99 participants in 3 patient groups, including a placebo group

Intramuscular phenylephrine group

Experimental group

Description:

Patients in intramuscular phenylephrine group will receive spinal anesthesia with bupivacaine. 5 mg (1ml) phenylephrine intramuscular injection will be given into the gluteus maximus muscle before anesthesia.1ml of 0.9% normal saline intravenous injection will be given after the subarachnoid injection is completed.

Treatment:

Drug: Bupivacaine

Drug: Phenylephrine

Drug: Normal saline

Intravenous phenylephrine group

Active Comparator group

Description:

Patients in intravenous phenylephrine group will receive spinal anesthesia with bupivacaine. 1ml of 0.9% normal saline intramuscular injection will be given into the gluteus maximus muscle before anesthesia.100ug (1ml) phenylephrine intravenous injection will be given after the subarachnoid injection is completed.

Treatment:

Drug: Bupivacaine

Drug: Phenylephrine

Drug: Normal saline

Placebo group

Placebo Comparator group

Description:

Patients in intravenous phenylephrine group will receive spinal anesthesia with bupivacaine. 1ml of 0.9% normal saline intramuscular injection will be given into the gluteus maximus muscle before anesthesia. 1ml of 0.9% normal saline intravenous injection will be given after the subarachnoid injection is completed.

Treatment:

Drug: Bupivacaine

Drug: Phenylephrine

Drug: Normal saline