The Effects of Low-Flow and Normal-Flow Sevoflurane Anesthesia on Frontal QRS-T Angle and TP-e Interval

NCT07571980 | Not Yet Recruiting

• 1 other identifier: 96-2026
• Study Type: observational
• Target: 128
• Locations: 0 countries
• Sites: N/A

Brief Summary

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.

Conditions

Cardiac Arrhythmia; Anesthesia

Outcome Measures

Primary Outcomes (2)

• Frontal QRS-T angle

  electrocardiogram

  Pre-operative period, 5 minutes after induction, 15 minutes after induction, post operative 15th minute

• Tp-e interval

  electrocardiogram

  Pre-operative period, 5 minutes after induction, 15 minutes after induction, post-operative 15th minute

Secondary Outcomes (5)

• blood pressure

  during peri-operative period

• heart rate

  during peri-operative period

• Tp-e/QT ratio

  Pre-operative period, 5 minutes after induction, 15 minutes after induction, post-operative 15th minute

• Total amount of volatile anesthetic consumed

  end of operation

• Total amount of Remifentanil consumed

  end of operation

Study Arms (2)

Low-Flow Group (LFG)

Anesthesia induction and initial stabilization (first 6-8 minutes at 4-6 L/min) follow standard hospital protocols. Fresh Gas Flow (FGF) reduced to 0.5 L/min after the target concentration (MACage +1) is reached. Ventilation parameters are adjusted to maintain end-tidal carbon dioxide (EtCO2) between 35-45 mmHg with a minimum FiO2 of 0.30. Volatile anesthetics are discontinued 15 minutes before the estimated end of surgery. Pre-oxygenation and wash-out are performed at 5-6 L/min with 80% oxygen prior to extubation.

Procedure: low flow anesthesia

Normal-Flow Group (NFG)

Anesthesia induction and initial stabilization (first 6-8 minutes at 4-6 L/min) follow standard hospital protocols. Fresh Gas Flow (FGF) maintained at 2 L/min during anesthesia maintenance. Ventilation parameters are adjusted to maintain end-tidal carbon dioxide (EtCO2) between 35-45 mmHg with a minimum FiO2 of 0.30. Volatile anesthetics are discontinued 15 minutes before the estimated end of surgery. Pre-oxygenation and wash-out are performed at 5-6 L/min with 80% oxygen prior to extubation.

Interventions

low flow anesthesia PROCEDURE

Fresh Gas Flow (FGF) reduced to 0.5 L/min after the target concentration (MACage +1) is reached.

Low-Flow Group (LFG)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

The study population consists of adult patients (aged 18 years and older) scheduled for elective or semi-elective laparoscopic cholecystectomy at a tertiary care training and research hospital.

You may qualify if:

• 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.

You may not qualify if:

• 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.).

Sponsors & Collaborators

• Istanbul University: lead

Related Publications (3)

• 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 BACKGROUND

• 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 BACKGROUND

• 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 BACKGROUND

MeSH Terms

Conditions

Arrhythmias, Cardiac

Condition Hierarchy (Ancestors)

Heart Diseases; Cardiovascular Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: specialist in anesthesiology

Study Record Dates

• First Submitted: April 30, 2026
• First Posted: May 7, 2026
• Study Start (Estimated): May 15, 2026
• Primary Completion (Estimated): May 15, 2027
• Study Completion (Estimated): August 15, 2027
• Last Updated: May 7, 2026

Record last verified: 2026-04