Evaluate the efficiency of management with intravenous dexmedetomidine compared to intravenous ondansetron to achieve the disappearance of post-anesthetic shivering in a shorter time in the obstetric patient undergoing cesarean section under regional anesthesia.

Randomized clinical trial with 40 pregnant patients, between 18 and 45 years old with ASA (American Society of Anesthesiologist) II or III, undergoing scheduled or emergency cesarean section with regional anesthesia and who presented grade tremor 1 based on the BSAS (Bedside shivering assessment scale) scale, at the Hospital Central from San Luis Potosi, Mexico. The main objective of this study was to quantify the time that elapsed from the end of the administration of the medication until the disappearance of the tremor, which was measured in minutes; The evaluation of the disappearance, persistence or reappearance of the tremor was solely visual by the anesthesiology staff.

Inclusion Criteria:

• ASA II or III, undergoing scheduled or emergency cesarean section with regional anesthesia (hyperbaric bupivacaine 0.5% with morphine at 1 mcg Kg-1) and who presented tremor grade >1 based on the BSAS scale

Exclusion Criteria:

• Hemodynamic instability, heart disease or sinus bradycardia, allergy to any of the medications applied, psychiatric diseases or hypothermia <35.2 ºC measured by tympanic temperature.

It might be useful for other researchers to expand their investigations, nevertheless, in this moment it seems completed this branch of investigation.