Effect of Glycopyrrolate on Vasopressors Requirement for Non-elective Caesarean Section Under Spinal Anaesthesia

Intravenous glycopyrrolate has been investigated for its effect on haemodynamic changes after spinal anesthesia for caesarean delivery. Results from previous studies are conflicting as glycopyrrolate has shown to reduce, increase or had no effect on incidence of maternal hypotension and/or vasopressor requirement after spinal anaesthesia. A recent meta-analysis found that prophylactic glycopyrrolate does not prevent the incidence of spinal-induced hypotension; however, it reduces the total vasopressor requirement during elective caesarean delivery under spinal anaesthesia. Therefore, the aim of this study is to find out whether the use of glycopyrrolate decreases the amount of vasopressors required to manage hypotension induced by spinal anaesthesia in non-elective CS.

Methodology:

After approval from Institutional Review committee of B.P. Koirala Institute of Health Sciences, the trial will be registered at clinical trial.gov. Parturient planned for non-elective caesarian of ASA PS grade II fulfilling the inclusion criteria will be informed about the study and written consent will be obtained either in labour room or in obstetric emergency ward. The eligible patients will be randomly assigned to Glycopyrrolate (GP group) or normal saline (NS group). The study will be conducted in accordance with the ethical principles of the 1964 Declaration of Helsinki. Before patient is shifted to the operating room (OR), ranitidine 50 mg and metoclopramide 10 mg will be administered intravenously via 18 G cannula. In the operating table, patients will be laid supine with a wedge placed in the right hip. Standard anaesthesia monitoring including 3-lead electrocardiography, heart rate (HR), noninvasive blood pressure (NIBP) and pulse oximetry (Sp02) will be done. A mean value of three measurements of systolic blood pressure (SBP) and HR will be recorded as baseline parameters. Patency of the vein will be maintained with the infusion of Ringer's lactate solution at a minimal rate.

Before the patient is placed in sitting position for SA,she will receive the study drug according to the randomization. After free flow of CSF is observed, 0.5 % hyperbaric bupivacaine (2.2 ml) with 10 µg fentanyl will be injected intrathecally over 30 s using a 25-gauge Quinke needle at the L3-4 or L4-L5 interspace. Patients will then be immediately placed in supine while maintaining 15 degree left lateral tilt. Co-loading of 1000 ml ringers lactate solution will be initiated at the start of spinal anaesthesia using a pressure bag and it will be completed within 10 min. Immediately after the spinal injection, phenylephrine infusion will be initiated at a rate of 25 µg/min and it will be titrated to maintain maternal SBP within 20 % of baseline.

The sensory level of anaesthesia will be checked using loss of cold sensation. Surgery will be allowed once the bilateral sensory block height at T6 is achieved. Oxygen at 40% will be administered via nasal cannula at 2-4 L/min until delivery.