Comparison of Effect of Two Different Doses of Intravenous Oxytocin on Patients Undergoing Elective Cesarean Section

Uterine atony and postpartum hemorrhage are important causes of maternal morbidity and mortality following cesarean section. Oxytocin is routinely administered to stimulate uterine contractions and prevent postpartum uterine atony. However, higher doses, particularly when administered rapidly, may produce cardiovascular effects such as vasodilatation, hypotension, reflex tachycardia, and increased cardiac output. Previous studies comparing low-dose and high-dose oxytocin have reported conflicting findings regarding adequate uterine contractions and blood loss. Therefore, further investigation is required to determine the comparative effectiveness of different oxytocin doses during elective cesarean section. The objective of this randomized controlled trial is to compare the effects of two different doses of intravenous oxytocin (5 IU and 10 IU) in patients undergoing elective cesarean section in terms of adequate uterine contractions and blood loss. The study will be conducted in the Department of Obstetrics and Gynecology, Shalamar Hospital, Lahore, over six months after approval of the synopsis. A total of 120 pregnant women will be enrolled through non-probability consecutive sampling. Eligible participants will be aged 18-35 years, with a gestational age of 37-42 weeks, ASA physical status I or II, uncomplicated pregnancies, and scheduled for elective cesarean section under spinal anesthesia. Women with active labour, multiple pregnancy, premature rupture of membranes, pregnancy-induced hypertension, preeclampsia, increased bleeding risk, coagulation abnormalities, thrombocytopenia, or oxytocin hypersensitivity will be excluded. After obtaining informed written consent, participants will be randomly allocated through the lottery method into two equal groups. Group A (n=60) will receive 5 IU intravenous oxytocin, while Group B (n=60) will receive 10 IU intravenous oxytocin at the time of umbilical cord clamping. The assigned dose will be diluted in 1,000 ml of normal saline or Ringer's lactate solution and administered according to the approved study protocol. All procedures will be performed by the same team to minimize procedural variation. The primary outcomes will be adequate uterine contractions and blood loss. Adequate uterine contractions will be defined as at least one contraction at three minutes, lasting 40-60 seconds, with sufficient intensity to make the uterus feel firm on palpation. Blood loss will be measured by combining blood collected in a kidney tray and measured using a graduated cylinder with blood retained on gauze, estimated through weight difference. Secondary observations will include nausea, vomiting, hypotension, and headache. Data will be analyzed using SPSS version 26. Numerical variables will be presented as mean and standard deviation, while categorical variables will be presented as frequencies and percentages. The chi-square test will be used for group comparisons of categorical outcomes. Stratification will be performed according to age, gestational age, and body mass index. A p-value of ≤0.05 will be considered statistically significant. The study will help determine the comparative effectiveness of 5 IU and 10 IU intravenous oxytocin in achieving adequate uterine contractions and controlling blood loss during elective cesarean section.

Inclusion Criteria: * Pregnant women aged 18 to 35 years, with a gestational age between 37 and 42 weeks, classified as ASA physical status I or II, and scheduled for elective cesarean section under spinal anesthesia will be included. * Uncomplicated pregnancy, confirmed by absence of medical or obstetric complications (e.g., hypertension, diabetes, fetal anomalies) and normal findings on antenatal history, clinical examination, and ultrasound records * Clear indication for elective cesarean section, such as a previous cesarean section without a planned VBAC, malpresentation (e.g., breech or transverse lie), non-bleeding placenta previa, maternal request after proper counseling, or clinically/radiologically diagnosed cephalopelvic disproportion. Exclusion Criteria: * Pregnant women aged 18 to 35 years, with a gestational age between 37 and 42 weeks, classified as ASA physical status I or II, and scheduled for elective cesarean section under spinal anesthesia will be included. * Uncomplicated pregnancy, confirmed by absence of medical or obstetric complications (e.g., hypertension, diabetes, fetal anomalies) and normal findings on antenatal history, clinical examination, and ultrasound records * Clear indication for elective cesarean section, such as a previous cesarean section without a planned VBAC, malpresentation (e.g., breech or transverse lie), non-bleeding placenta previa, maternal request after proper counseling, or clinically/radiologically diagnosed cephalopelvic disproportion.