Pregnancy, Cesarean Section, Anesthesia,Spinal, Hypotension
Conditions
Keywords
Ephedrine, Adrenergic Agents, Central Nervous System Stimulants, Sympathomimetics, Vasoconstrictor Agents, Bupivacaine, Anesthetics, Local, Atropine, Adjuvants, Anesthesia, Anti-Arrhythmia Agents, Bronchodilator Agents, Muscarinic Antagonists, Mydriatics, Parasympatholytics, Morphine, Analgesics, Opioid, Narcotics, Ringer's Lactate, Isotonic Solutions, Hypotension, Blood pressure, Signs and Symptoms, Pregnancy, Anesthesia, Obstetrical, Inferior Vena Cava
Brief summary
The aim of this study is to compare two different therapeutic approaches to blood pressure reduction: pharmacological vs. non-pharmacological. The setting is that of patients undergoing scheduled Cesarean section under spinal anesthesia and suffering from aorta-caval compression syndrome, which causes a sudden drop in blood pressure.
Detailed description
The supine hypotensive syndrome of pregnancy is induced by compression of the inferior caval vein by the enlarged uterus. It occurs in approximately 8% of pregnant women at term. More patients may develop an asymptomatic variety of this syndrome in the supine position. The hypotensive effect of spinal anesthesia per se may thus be aggravated in a significant number of term parturients. A preoperative supine stress test (SST) before elective cesarean section under spinal anesthesia has been shown to predict severe systolic hypotension with reasonable accuracy. Different strategies have been proposed for the management of this complication; they can be divided into pharmacological and non-pharmacological ones. According to pharmacological strategies, vasoactive drugs are used to treat hypotension induced by sympathetic efferent blockade following spinal anesthesia. To this end, α-agonist ephedrine is commonly considered the best choice because of its minimal impact on the fetoplacental circulation. However, excessive use of ephedrine may be detrimental to neonatal well-being because of its vasoconstrictor effect on fetoplacental circulation. Non-pharmacological treatments may represent a valuable, safer alternative. According to many authors non-pharmacological treatments aimed at removing the cause of aorta-caval compression syndrome are to be preferred because more appropriate from an etiopathogenetic point of view. The use of a wedge-shaped cushion placed under the right hip is a well-known non-pharmacological strategy which allows the uterine left lateral displacement and, consequently, the removing of the compression from the inferior vena cava. The aim of the present study is to compare, through the evaluation of neonatal well-being, the efficacy of these approaches to hypotension after spinal anesthesia for elective Caesarean section in parturients affected by aorto-caval compression.
Interventions
DRUGBupivacaine
10 mg of a 5 mg/ml hyperbaric solution, intrathecally
DRUGMorphine
200 µg of a 100 µg/ml solution, intrathecally
25 ml/min intravenously
DRUGEphedrine, continuous infusion
37.5 mg/h intravenously
DRUGEphedrine, bolus
6.25 mg IV bolus prn. Hypotension defined according to study protocol for each arm.
DRUGAtropine
0.1 mg/kg iv bolus prn Bradycardia defined as 50% drop in heart rate from baseline values.
Sponsors
Azienda Ospedaliero-Universitaria di Parma
University of Parma
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 50 Years
Healthy volunteers
No
Inclusion criteria
* Patients undergoing spinal anesthesia for elective Cesarean section * Patients in ASA Physical Status Class I or II * Informed written consent to participation * Positive Supine Stress Test
Exclusion criteria
* Any known fetal pathology * Indication to general anesthesia * Known allergy to any of the study drugs
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Neonatal arterial base excess | <5 min from birth |
Secondary
| Measure | Time frame |
|---|---|
| Apgar score | 1 and 5 minutes from birth |
| Maternal serum levels of cardiac troponin (baseline, immediate postsurgery, 6 and 12 hours after surgery) | Baseline and up to 12 h postoperatively |
| Incidence of maternal hypotension ( <20% baseline or mean arterial pressure <60 mmHg). | q5min from anesthesia to end of surgery |
| Incidence of maternal bradycardia (heart rate <30% of baseline or <60 beats per minute) | q5min from anesthesia to end of surgery |
| Neonatal arterial and venous pH, venous base excess | <5 min from birth |
| Administered atropine | from anesthesia to end of surgery |
| Amount of ephedrine administered (mg) | from anesthesia to end of surgery |
| Time between induction of anesthesia and skin incision | — |
| Time between skin incision and delivery | — |
| Peripheral arterial oxygen saturation: incidence of desaturation (SpO2 <92%) and mean values for each arm. | q5min from anesthesia to end of surgery |
Countries
Italy
Outcome results
None listed