The Effects of Low-Flow and Normal-Flow Sevoflurane Anesthesia on Frontal QRS-T Angle and TP-e Interval
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: low flow anesthesia.
- Who it may be relevant to
- Registry conditions: Cardiac Arrhythmia, Anesthesia. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Center list to be confirmed — check the primary protocol.
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
The Effects of Low-Flow and Normal-Flow Sevoflurane Anesthesia on Frontal QRS-T Angle and TP-e Interval in Patients Undergoing Elective Laparoscopic Cholecystectomy
Overview
Laparoscopic cholecystectomy procedures involve pneumoperitoneum and volatile anesthetics, both of which can significantly influence cardiovascular physiology and autonomic balance. While volatile anesthetics are known to affect myocardial repolarization, the specific impact of Low-Flow Anesthesia (LFA)-a cost-effective and environmentally friendly technique-on these cardiac markers remains under-researched. This prospective observational study aims to compare the effects of low-flow versus normal-flow sevoflurane anesthesia on two critical non-invasive biomarkers of ventricular repolarization: the Frontal QRS-T angle and the Tp-e interval. These parameters are essential for predicting electrical instability and the risk of malignant arrhythmias. The study will evaluate a total of 128 patients to determine whether different fresh gas flow rates lead to significant changes in cardiac electrophysiological stability during the perioperative and early postoperative periods.
Detailed description
This prospective observational study is designed to investigate the electrophysiological effects of different fresh gas flow rates during sevoflurane anesthesia in patients undergoing elective laparoscopic cholecystectomy. Laparoscopic procedures involving pneumoperitoneum and volatile anesthetics are known to influence autonomic nervous system balance and cardiovascular stability. While the impact of inhalation agents on myocardial repolarization is documented, the specific effects of Low-Flow Anesthesia (LFA)-an environmentally and economically favorable technique-on markers of electrical instability remain to be fully elucidated. The primary objective is to evaluate and compare the effects of low-flow and normal-flow sevoflurane techniques on the Frontal QRS-T angle and the Tp-e interval, which serve as critical non-invasive biomarkers for predicting malignant arrhythmia risk and reflecting the transmural distribution of ventricular repolarization.
The study protocol involves 128 patients, a sample size determined by power analysis (80% power, 0.05 alpha) to account for a predicted 35% difference between groups and potential dropouts. Patients are observationally assigned to either the Low-Flow Group (LFG) or the Normal-Flow Group (NFG) according to routine clinical practice. Following a standardized induction and an initial stabilization phase at 4-6 L/min, flow rates are adjusted once the target concentration (MACage +1) is reached: the LFG is reduced to 0.5 L/min, while the NFG is maintained at 2 L/min. Ventilation is managed to keep EtCO2 between 35-45 mmHg. Data collection is performed via high-resolution ECG recordings at four time points: preoperative baseline (T1), 5 minutes post-intubation (T2), 15 minutes post-intubation (T3), and 15 minutes postoperatively (T4).
Another key focus of this research is the detailed analysis of secondary outcomes, including the monitoring of hemodynamic stability (mean arterial pressure and heart rate) across all time points. Furthermore, the study aims to characterize the electrophysiological profile of each technique by analyzing the Tp-e/QT ratio and calculating time-dependent variations in repolarization parameters, specifically the delta changes from baseline to intraoperative stages (ΔT1-T2 and ΔT1-T3). Additionally, a cost-effectiveness analysis will be conducted by determining the total volume of volatile anesthetic consumed in both techniques. Statistical analysis will involve independent samples t-tests for inter-group comparisons, while repeated measures ANOVA with Bonferroni correction will evaluate time-dependent changes. Pearson correlation analysis will be utilized to assess the relationships between continuous variables, providing a comprehensive assessment of the safety and efficacy of low-flow versus normal-flow anesthesia management.
Interventions
- Procedure low flow anesthesia
Fresh Gas Flow (FGF) reduced to 0.5 L/min after the target concentration (MACage +1) is reached.
Primary outcome measures
- Frontal QRS-T angle [Time frame: Pre-operative period, 5 minutes after induction, 15 minutes after induction, post operative 15th minute]
- Tp-e interval [Time frame: Pre-operative period, 5 minutes after induction, 15 minutes after induction, post-operative 15th minute]
Secondary outcome measures (5)
- blood pressure [Time frame: during peri-operative period]
- heart rate [Time frame: during peri-operative period]
- Tp-e/QT ratio [Time frame: Pre-operative period, 5 minutes after induction, 15 minutes after induction, post-operative 15th minute]
- Total amount of volatile anesthetic consumed [Time frame: end of operation]
- Total amount of Remifentanil consumed [Time frame: end of operation]
Eligibility criteria
Inclusion criteria
- Patients aged 18 years and older.
- Patients scheduled for elective or semi-elective laparoscopic cholecystectomy.
- Patients who provide written voluntary informed consent.
- Patients with a predicted surgical duration between 60 and 180 minutes.
Exclusion criteria
- Patients with heart failure.
- Patients with valvular heart disease or pathology.
- Patients with hemodynamic instability.
- Patients requiring blood transfusion.
- Patients with a preoperative corrected QT (QTc) interval > 450 ms.
- Patients with a known history of cardiac arrhythmia.
- Patients scheduled for emergency surgery.
- Patients with a known risk or family history of malignant hyperthermia.
- Use of medications associated with QT interval prolongation (e.g., ketamine, 5-HT3 antagonists, quetiapine, etc.).
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Observational model
- Cohort
Study locations
Center list to be confirmed — check the primary protocol.
Publications
- Yildirim H, Adanir T, Atay A, Katircioglu K, Savaci S. The effects of sevoflurane, isoflurane and desflurane on QT interval of the ECG. Eur J Anaesthesiol. 2004 Jul;21(7):566-70. doi: 10.1017/s0265021504007112. PMID 15318470
- Kim NY, Han DW, Koh JC, Rha KH, Hong JH, Park JM, Kim SY. Effect of Dexmedetomidine on Heart Rate-Corrected QT and Tpeak-Tend Intervals During Robot-Assisted Laparoscopic Prostatectomy With Steep Trendelenburg Position: A Prospective, Randomized, Double-Blinded, Controlled Study. Medicine (Baltimore). 2016 May;95(19):e3645. doi: 10.1097/MD.0000000000003645. PMID 27175685
- Bingol Tanriverdi T, Tercan M, Patmano G, Tanriverdi Z, Gusun Halitoglu A, Kaya A. The Effect of Low-Flow and Normal-Flow Desflurane Anesthesia on the Frontal QRS-T Angle in Patients Undergoing Rhinoplasty Operation: A Randomized Prospective Study. Cureus. 2022 Sep 8;14(9):e28920. doi: 10.7759/cureus.28920. eCollection 2022 Sep. PMID 36225439
Identifiers
NCT: NCT07571980 · 96-2026