Background & Objectives: Nitroglycerin is found to have vasodilatory effect. It has also a relaxing effect on the smooth muscles of other organs including uterus. This study investigates the effect of intravenous nitroglycerin in emergency cesarean sections in which rapid and transient uterine relaxation for rapid and nontraumatic extraction of the fetus is necessary.

  Methods: Sixty pregnant women who were candidated for emergency cesarean and needed rapid uterine relaxation for different reasons were selected. These subjects underwent spinal anesthesia and at the time of uterine incision, 100 micrograms of nitroglycerin was injected to them intravenously. The time lapse between nitroglycerin administration and fetal extraction, the degree of uterine relaxation, the amount of intraoperative hemorrhage, uterine tone after fetal delivery and APGAR scores of the infants were all controlled and recorded. Also with regard to the vasodilatory effect of nitroglycerin and probably its resultant homodynamic problems, blood pressure, heart rate and arterial O₂ saturation were recorded before and after nitroglycerin injection and throughout the surgery.

  Results: The results showed that in 53 (88.3%) of the patients the uterus was acceptably relaxed and the fetus was delivered very easily. Only in 7 patients (11.7%) uterine relaxation was not acceptable. The mean decrease in systolic and diastolic blood pressures after nitroglycerin administration compared with before injection BP was 12.97 mmHg (12.210 %) and 7.86 mmHg (12.208 %), respectively. There was not seen any prolonged effect of the drug such as uterus relaxation tone or abnormal bleeding. Also, none of the delivered infants had low APGAR scores. Besides, in patients with acceptable uterine relaxation the first and fifth minute APGAR score of infants were higher (p = 0.008, p = 0.000).

  Conclusion: This study shows that nitroglycerin can relax uterine smooth muscles very rapidly and transiently and in emergencies it can be an appropriate alternative to the other tocolytic agents with prolonged effect or onset time.

  Background & Objectives: Oculocardiac reflex (OCR) is presented with bradycardia and other arrhythmias, is induced by mechanical stimulation and therefore, encountered during strabismus surgery. The aim of this study is to determine the incidence and risk factors of cardiac arrhythmias during strabismus surgery in children and adults.

  Methods: In this prospective, randomized and double-blind study, 46 patients ASA class I and II underwent elective strabismus surgery with general anesthesia and were allocated to one of the two groups: children under 12 and adults over 12. All patients received standard general anesthesia based on their age. Demographic data, type of involved muscle, the incidence, (type and frequency) and the cause of arrhythmias and skillfulness of the surgeon (professor-assistant) were recorded.

  Results: There were 26 patients in children group and 20 patients in adult group. The overall incidence of arrhythmias was 91% with 96.15% in children and 85% in adults. There was not any significant difference in the incidence of arrhythmias, and the mean rate of occurence between two groups. Most of the arrhythmias were due to external ocular muscles traction. Conjunctival traction and pressure on the globe were the other causes. Stimulation of median rectus muscle as the most important arrythmogenic factor was seen in 13 children and 12 adults. Bradycardia and tachycardia were among common arrhythmias, but there was no significant difference between two groups (P>0.05) in terms of their incidence.

  Conclusion: This study showed that the incidence of arrhythmias during strabismus surgery is high in both children and adults. This reflex does not often lead to hemodynamic compromise, however, for its early diagnosis and treatment, close and continuous monitoring of the patient as well as cooperation and communication between anesthesiologist and surgon is needed.