An observational study on haemodynamic changes due to intramyometrial vasopressin injection in patients undergoing elective gynaecologic surgeries (Myomectomy, Hysterectomy)

Uterine Fibroid is themost prevalent type of benign tumor in the female reproductive system with theprevalence of 24-40% among adult females. About 10% of the myomas aresubmucosal. Myoma is mostly asymptomatic. Size and location are the mainfactors that determine if a myoma leads to symptoms. One of the surgicalmanagement of fibroid is myomectomy. Myomectomy is associated with intraoperative complications such as excessive bleeding because of its rich blood supply. Thereforeproper haemostasis and layered closure of uterus following myomectomy are veryimportant  to minimize complications.Bleeding can be prevented if dissection done through the avascular cleft ordecreased with mechanical or pharmacological methods. One of the commonly usedpharmacologic method is use of vasopressin.In this background we decided to do anobservational study on hemodynamic changes with intramyometrial vasopressin inpatients undergoing elective gynaecological surgeries (myomectomy,hysterectomy) for fibroid uterus.

Study will be conducted on 125 women with symptomatic fibroids belongs toAmerican Society of Anaesthesiologists Physical Status I & II whom are postedfor elective laparoscopic or open myomectomy or  hysterectomy. Patients will be approached by primaryinvestigator on the day prior to surgery after discussing with the surgicalteam. Informed consent will be taken from the patient. On the day of surgerybaseline vital parameters will be recorded. The induction of anaesthesia willbe done for all patients by preoxygenation with 100% oxygen, intravenousFentanyl (1-2mcg/kg), propofol (1-2mg/kg), Atracurium (0.5mg/kg). Aftertracheal intubation anaesthesia will be maintained with oxygen: air (50:50%)and Isoflurane (2-3%). An additional dose of intravenous Atracurium (0.08-0.1mg/kg)will be given guided by the peripheral nerve stimulator to provide atrain-of-four count zero. The ventilation will be adjusted to maintain EtCo2 30-35mmHg. Isoflurane concentration will be adjusted to maintain the mean arterialblood pressure and heart rate within 20% of the pre-induction values. Intraoperativetachycardia (heart rate >100bpm) and hypertension (mean arterial bloodpressure >20% above baseline) will be managed by increasing theconcentration of Isoflurane by increments of 1.0% and bolus doses of Fentanyl(0.05-1mcg/kg). Intraoperative hypotension (mean arterial blood pressure<20% below baseline) will be managed by bolus doses of Ephedrine and fluidadministration. Bradycardia (heart rate <60bpm) will be managed by a bolusdose of Atropine (0.02mg/kg). At the end of the surgery the Isoflurane will bediscontinued and controlled ventilation with 100% oxygen will be maintaineduntil the end tidal Isoflurane concentration becomes <0.1%. Residualneuromuscular blockade will be reversed with a combination of Neostigmine(0.05mg/kg) and Glycopyrrolate (0.01mg/kg) intravenously and then the patientwill be extubated OR If regional anaesthesia is planned Spinal / Combined spinal Epiduralanaesthesia will be given by the anaesthetist posted in the theatre.

The parameters- heart rate, systolic, diastolic and mean arterial blood pressure, ECGmonitoring, arterial oxygen saturation(SPO2), end tidal carbon dioxide(EtCO2)will be recorded at serial intervals. These parameters will be recorded byconcerned anesthetist posted in the list on the day of surgery.

1. VITAL SIGNS

T0    :   preoperative value

T1    :   5 minutes after induction

T2    :    justbefore intramyometrial vasopressin administration

T3    :   1minute after vasopressin administration

T4    :   2 minutes after vasopressin administration

T5    :   3 minutes after vasopressin administration

T6    :   4minutes after vasopressin administration

T7    :   5minutes after vasopressin administration

T8    :  10minutes after vasopressin administration

T9    :  15minutes after vasopressin administration

T10  :  20minutes after vasopressin administration

T11  :  30 minutes after vasopressin administration

T12  :  45 minutes after vasopressin administration

T13  :  60 minutes after vasopressin administration

T14  :   after 60 minutes in the postoperative care unit

2. Episodes of hypotension/hypertension /treatment

3. Episodes of Tachycardia/bradycardia/treatment

4. Episodes of Arrhythmia/treatment

5. ECG Changes

6. Pulmonary edema

7. Cardiac arrest

8. Any other adverse event

 OTHER DATA :

9. Vasopressin: concentration of drug in one ml of saline /amount of druginjected/speed & number(single/multiple) and duration of injection /injection by PG/Consultant /size of needle

10 .Blood loss

11 .Details of blood transfusion

Also the incidenceof hypotension, hypertension, bradycardia, tachycardia, arrhythmia, ECG changesand any adverse effects will be documented. The total amount of blood loss willbe assessed by measuring the amount of blood in the suction bottle and visualestimation of gauze visual analogue. The primary outcome measured will be thesafety of the drug vasopressin as assessed by the occurrence of anycardiovascular complications (arrhythmia, hypertension, myocardial ischemia,pulmonary edema). The secondary outcome measured will be the blood loss andrequirements for blood transfusion.