Study of the Effect of Intramuscular Ephedrine on the Incidence of Nausea and Vomiting During Elective Cesarean Section

Study of the Effect of Intramuscular Ephedrine on the Incidence of Nausea and Vomiting During Elective Cesarean Section

A Double-Blind, Placebo-Controlled Study to Evaluate the Effect of Intramuscular Ephedrine on the Incidence of Perioperative Nausea and Vomiting During Elective Cesarean Section

The purpose of this research study is to investigate if the incidence of nausea and vomiting that subjects experience during and after a Cesarean section can be reduced by giving a shot of the drug ephedrine into the thigh muscle at the time of spinal anesthesia administration.

This research project is designed to study the medication ephedrine, when it is given as a routine part of the anesthesia for elective Cesarean section. Ephedrine is a medication that is widely used in labor and in vaginal and operative (Cesarean section) deliveries to help maintain a woman's blood pressure within its normal range, especially after spinal and epidural anesthesia has been administered. The purpose of this study is to determine if ephedrine, when given intramuscularly (<IM> as a shot in the muscle), at the time of spinal anesthesia administration, can help to decrease the incidence of nausea and vomiting subjects experience during and after a Cesarean section. This study will compare women who receive ephedrine to a similar group of women who receive a normal saline placebo. In addition to looking at the difference in the incidence of nausea and vomiting perioperatively, this study will also evaluate if the administration of IM ephedrine helps the baby to receive more blood from the placenta after anesthesia has been administered to the mother. This will be evaluated by performing a simple blood test, drawn from the umbilical cord, after the baby is born.

Subject's self-rated nausea level on a scale of 0-3 immediately prior to induction of spinal anesthesia, where 0=no nausea, 1=mild nausea, 2=moderate nausea, and 3=severe nausea

Subject's Self-rated Intra-operative Nausea Level on a Scale of 0-3, Where 0=no Nausea, 1=Mild Nausea, 2=Moderate Nausea, and 3=Severe Nausea.

Subjects were asked to rate their nausea level on a scale of 0-3, where 0=no nausea, 1=mild nausea, 2=moderate nausea, and 3=severe nausea, five times during their procedure: 1) Immediately prior to skin incision, 2) immediately following delivery of the baby, 3) following reinternalization of the uterus, 4) following closure of the fascia, 5) following closure of the skin. The numbers given by the subject were then averaged to determine the average level of nausea intra-operatively for each subject.

Subjects were asked to rate their nausea level on a scale of 0-3, where 0=no nausea, 1=mild nausea, 2=moderate nausea, and 3=severe nausea two times after the conclusion of their surgery: 1) upon arrival in the PACU, and 2) immediately prior to discharge from the PACU. The numbers given by the subject were then averaged to determine the average level of nausea post-operative for each subject.

Inclusion Criteria: Must be pregnant with a single baby Must be at term in their pregnancy (estimated gestational age of at least 38 weeks) Must be scheduled for an elective Cesarean section Must be between 60-70" tall Must be free of severe systemic disease (ASA class I or II) Exclusion Criteria: Contraindication to spinal anesthesia Any allergy to any of the medications included in the study History of pregnancy-induced hypertension or preeclampsia History of preexisting hypertension Diabetes mellitus Hyperemesis gravidum Previous perioperative nausea and vomiting History of motion sickness Women carrying a fetus with a known abnormality will also be excluded from the study

Griffiths JD, Gyte GM, Popham PA, Williams K, Paranjothy S, Broughton HK, Brown HC, Thomas J. Interventions for preventing nausea and vomiting in women undergoing regional anaesthesia for caesarean section. Cochrane Database Syst Rev. 2021 May 18;5(5):CD007579. doi: 10.1002/14651858.CD007579.pub3.