Anesthesia oxytocin

Drug interactions Co-administration of dinoprostone in patients receiving intravenous oxytocic agents such as oxytocin may result in uterine hyperstimulation and is therefore contraindicated. Severe hypertension has been reported when oxytocin was given 3 to 4 hours following prophylactic administration of a vasoconstrictor in conjunction with spinal anesthesia. Oxytocin may enhance the neuromuscular blockade of succinylcholine. 

In 34 women undergoing cesarean section at full term under spinal anesthesia, heart rate and cardiac output increased significantly within 2 minutes of the rapid administration of either 5 or 10 units of oxytocin, with an associated 10 mmHg fall in mean arterial pressure in those who received 10 units (6). There were significant ST segment changes in 11 of 26 women undergoing cesarean section, with raised concentrations of troponin I in two however, the relationship to oxytocin administration was not clear in this report (7). 

When epidural anesthesia was used for cesarean section, bupivacaine (with oxytocin) produced a higher frequency of neonatal jaundice than similar treatment using lidocaine (SEDA-14, 111). 

Dyer RA, Reed AR, van Dyk D, Arcache MJ, Hodges O, Lombard CJ, Greenwood J, James MF. Hemodynamic effects of ephedrine, phenylephrine, and the coadministration of phenylephrine with oxytocin during spinal anesthesia for elective cesarean dehvery. Anesthesiology 2009 111(4) 753-65. 

A 26-year-old woman in the second stage of labor received an infusion of oxytocin 10 U/l in 5% dextrose at a variable rate of 10-150 ml/ hour. In the 5 hours after delivery, which was complicated by a retained placenta requiring general anesthesia for removal, she received isotonic fluid 5500 ml, 5% dextrose 3500 ml with oxytocin 50 U/l, hydroxyethyl starch 1000 ml, and 4 units of blood. She then received 5% dextrose 7500 ml with oxytocin 100 U/l over 15 hours 24 hours later her serum sodium concentration was 113 mmol/l. She became unconscious and had a generalized convulsion. She subsequently made a full recovery. 

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