Comparison of the Effects of Spinal and General Anesthesia on the QTc Interval in Cesarean Section Patients

Study design and setting:

Researchers designed a prospective randomized study to compare the effects of spinal anesthesia and general anesthesia on the QT interval in patients undergoing elective cesarean section delivery. The study has been approved by the local Institutional Review Board (Ethics Committee of Health Science University Haseki Training and Research Hospital, Istanbul, Türkiye; approval date: 04 October 2023; approval number: 169-2023). The research was performed acoording to the Declaration of Helsinki, and written informed consent was obtained from all participants The study was carried out at a university affiliated hospital with 700-bed in Istanbul, Türkiye between October 4 2023 and December 4 2023.

Patient selection and group allocation The patients enrolled in the study were selected from 64 consecutive pregnant women who scheduled for an elective cesarean section delivery (Figure 1). Exclusion criteria were baseline QTc >440 ms, use of medications that affect the QTc interval, family history of long QT syndrome, electrocardiographic evidence of arrhythmia and/or conduction abnormalities, or the presence of a permanent pacemaker, contraindications to spinal anesthesia (high intracranial pressure, injection site infection, coagulation disorders, severe hypovolemia, aortic and/or mitral stenosis), history of spinal surgery, congenital spinal deformity or neuromuscular disease, anemia, electrolyte imbalance, significant cardiopulmonary/hepatic/renal disesase, obesity (Body Mass Index > 30 kg/m2), an American Society of Anesthesiologists (ASA) physical classification ≥III or refusal to participate.

In the preoperative ward an intravenous (iv) line was obtained and all the patients received 10 ml/kg isotonic saline) within 20 minutes. The patients were randomly allocated to either the spinal anesthesia group (Group S) or the general anesthesia group (Group G) using sealed envelope method by an independent investigator and then were transferred to the operating room.

Anesthesia procedure In the operating room the patients received isotonic saline at a rate of 8 mL/kg/h for intravenous hydration and prexoxgenation was obtained via face mask for 3 minutes (8 L/min).