EFFICACY OF PROPHYLACTIC ONDANSETRON ON PREVENTION OF HYPOTENSION INDUCED BY SPINAL ANESTHESIA IN OBSTETRIC AND NON OBSTETRIC PATIENTS

Abstract

Background and Aims: Spinal anesthesia (SA) is safe and effective technique for a range of
surgical procedures. SA related triggering of Bezold Zarisch reflex demonstrated by
hypotension, bradycardia and vasodilation is known to result from stimulation of 5-HT3
receptors in vagal nerve endings1,2,. Prophylactic administration of ondansetrona a 5-HT3
receptor blocker may reduce the side effects.
The aim of the present study is to verify the hypothesis that blockage of type 3 serotonin
receptors by intra venous ondansetron administration would reduce hypotension and
bradycardia induced by SA.
Method: The study was conducted on 140 patients undergoing SA . There were two sets of
population, obstetric and non obstetric. Each set of population had their own control group.
After taking the patient to the operation theatre, venous access was established, and basic
monitors were connected . Base line blood pressure and heart rate were noted before the SA..
Then in sitting position, SA was performed . After spinal, Heart rate(HR), systolic(SBP),
diastolic (DBP) and mean arterial pressure (MAP), and oxygen saturation (Sp02) were
recorded at time of spinal drug administration and at 2 min intervals upto 18 min. Adverse
effect such as nausea and vomiting, were monitored. Drop in systolic blood pressure to less
than or equal to 90 mm of Hg was treated with iv ephedrine 6 mg and HR fall to less than 50
beats per minute with iv 0.2 mg glycopyrrolate . Amount of ephedrine and glycopyrrolate
consumed were also noted.
The comparison of normally distributed continuous variables between the groups was
performed using Student's t-test. Nominal categorical data between the groups were
compared using Chi- squared test or Fisher's exact test as appropriate. P< 0.05 was
considered statistically significant..