Clinical trial NCT00991627: Different Approaches to Maternal Hypotension During Cesarean Section
Official title: Pharmacological or Non-Pharmacological Management of Maternal Hypotension During Elective Cesarean Section Under Subarachnoid Anesthesia: a Randomized, Controlled Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Pregnancy
Cesarean Section
Anesthesia,Spinal
Hypotension
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
Lead sponsor: University of Parma
Sponsor class: OTHER
Collaborators: name: Azienda Ospedaliero-Universitaria di Parma
First posted: 2009-10-08
Enrollment: 36
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

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.

Eligibility criteria: 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

Primary outcomes:
measure: Neonatal arterial base excess
timeFrame: <5 min from birth
Secondary outcomes:
measure: Neonatal arterial and venous pH, venous base excess
timeFrame: <5 min from birth
measure: Apgar score
timeFrame: 1 and 5 minutes from birth
measure: Maternal serum levels of cardiac troponin (baseline, immediate postsurgery, 6 and 12 hours after surgery)
timeFrame: Baseline and up to 12 h postoperatively
measure: Incidence of maternal hypotension ( <20% baseline or mean arterial pressure <60 mmHg).
timeFrame: q5min from anesthesia to end of surgery
measure: Incidence of maternal bradycardia (heart rate <30% of baseline or <60 beats per minute)
timeFrame: q5min from anesthesia to end of surgery
measure: Peripheral arterial oxygen saturation: incidence of desaturation (SpO2 <92%) and mean values for each arm.
timeFrame: q5min from anesthesia to end of surgery
measure: Administered atropine
timeFrame: from anesthesia to end of surgery
measure: Amount of ephedrine administered (mg)
timeFrame: from anesthesia to end of surgery
measure: Time between induction of anesthesia and skin incision
measure: Time between skin incision and delivery
Other outcomes:
Locations:
city: Parma
country: Italy
facility: University and Hospital of Parma (Azienda Ospedaliero-Universitaria di Parma)
state: PR
Study officials:
affiliation: Dept. of Anesthesiology and Critical Care Medicine, University of Parma, Italy
name: Guido Fanelli, MD
role: STUDY_CHAIR
affiliation: UO II Anestesia, Rianimazione e Terapia Antalgica, Azienda Ospedaliero-Universitaria di Parma
name: Andrea Cornini, MD
role: STUDY_DIRECTOR
affiliation: Dept. of Anesthesiology and Critical Care Medicine, University of Parma, Italy
name: Michele Zasa, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Kinsella SM, Lohmann G. Supine hypotensive syndrome. Obstet Gynecol. 1994 May;83(5 Pt 1):774-88.
citation: Cyna AM, Andrew M, Emmett RS, Middleton P, Simmons SW. Techniques for preventing hypotension during spinal anaesthesia for caesarean section. Cochrane Database Syst Rev. 2006 Oct 18;(4):CD002251. doi: 10.1002/14651858.CD002251.pub2.
citation: Kinsella SM, Norris MC. Advance prediction of hypotension at cesarean delivery under spinal anesthesia. Int J Obstet Anesth. 1996 Jan;5(1):3-7. doi: 10.1016/s0959-289x(96)80067-7.
citation: Helwig JT, Parer JT, Kilpatrick SJ, Laros RK Jr. Umbilical cord blood acid-base state: what is normal? Am J Obstet Gynecol. 1996 Jun;174(6):1807-12; discussion 1812-4. doi: 10.1016/s0002-9378(96)70214-4.