Measurement of Hemodynamic Variables Under Spinal Anesthesia With Varied Positioning

The University of Texas System (UT)

Status: Completed

Conditions: Anesthesia; Pregnancy

Treatments: Other: Right lateral position; Other: Supine position; Other: Left lateral position

Study type: Interventional

Funder types: Other

Identifiers

NCT02883075

IRB #16-0119

Details and patient eligibility

About

Multiple studies have compared spinal anesthetic performed supine versus lateral, with varying results, in parturients having elective cesarean section. Needle positioning during spinal placement has also been examined. No positioning techniques have demonstrated definitive superiority for hemodynamic stability.

Investigators propose that following spinal placement in the sitting position if the patient is placed in a lateral position for 90 seconds prior to turning them supine, hemodynamic changes caused by sympathectomy related to the subarachnoid block can be avoided.

This is the first study to examining the influence of position changes after spinal anesthetic placement in the sitting position, which includes hemodynamic variables not previously studied including cardiac output, TPR (total peripheral resistance) and pulse pressure variation (PPV).

Full description

Cesarean section is chosen when natural spontaneous vaginal delivery is either not possible or when the health of the baby or mother is compromised. Cesarean section may be planned, urgent, or performed emergently when the life of the baby or mother is threatened.

Cesarean section is performed using different anesthetic techniques including: spinal, epidural, combined spinal and epidural, and general anesthesia. Spinal anesthesia is the most common technique chosen due to its relative safety, rapid onset and avoidance of potential complications from general anesthesia. It is the technique of choice for elective cesarean section unless contraindicated. Spinal anesthesia causes sympathetic blockade followed by sensory and motor blockade. Nerve fiber size explains the speed of onset and differential block. The critical moments during spinal anesthesia come as soon as local anesthetic is injected into the subarachnoid space.

Enrollment: 61 patients

Sex: Female

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Parturients undergoing elective cesarean section under spinal anesthesia
• Singleton intrauterine pregnancy with appropriate gestational age fetus (AGA) at gestational age 37 to 42 weeks

Exclusion criteria

• Large for gestational age, small for gestational age, and multiple gestations
• Patients with cardiovascular disease like hypertension, etc.
• Non-English or non-Spanish speakers
• BMI >40
• Inadequate or failed blocks and inadvertently high levels of spinal blockade will be dropped from the study
• Incarcerated parturients
• Expected heavy bleeding (placenta accreta, vascular anomaly, etc.)

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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61 participants in 3 patient groups

Supine position

Sham Comparator group

Description:

Supine position Supine position after placement of spinal anesthetic

Treatment:

Other: Supine position

Right lateral position

Active Comparator group

Description:

Right lateral position Right lateral after placement of spinal anesthetic

Treatment:

Other: Right lateral position

Left lateral position

Active Comparator group

Description:

Left lateral position Left lateral after placement of spinal anesthetic

Treatment:

Other: Left lateral position