A Comparison of the Effects of Sevoflurane and Desflurane on Corrected QT Interval Prolongation in Patients Undergoing Living Donor Liver Transplantation: A Prospective Observational Study

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

Introduction: Low-flow anesthesia (LFA) has gained more interest worldwide owing to its economic and ecological advantages compared to normal-flow anesthesia (NFA). Desflurane is one of the commonly used anesthetic agents for LFA, but it may prolong myocardial repolarization. Frontal QRS-T angle (f[QRS-T]a) is a novel marker of myocardial repolarization. To our knowledge, no study has compared the effect of LFA and NFA on f(QRS-T)a. In this study, we aimed to compare the effect of the LFA and NFA with desflurane on f(QRS-T)a in patients undergoing rhinoplasty operation.

Methods: A total of 80 patients undergoing rhinoplasty operations were included in this prospective study. The patients were randomized into two groups as follows: LFA (n = 40) and NFA (n = 40). The frontal QRS-T angle was calculated from the automatic report of the electrocardiography device (Nihon Kohden, Tokyo, Japan). It was recorded at the following time points: T1: preoperative (basal), T2: immediately after anesthesia induction, T3: immediately after endotracheal intubation, T4: 5 min after endotracheal intubation, T5: 15 min after endotracheal intubation, T6: 30 min after endotracheal intubation, T7: 60 min after endotracheal intubation, T8: end of the operation, T9: 15 min after the end of the operation.

Results: Baseline clinical characteristics and laboratory parameters were similar between the two groups. In the LFA group, f(QRS-T)a was significantly increased at only the T3 time point when compared to T1 (P = 0.003). However, in the NFA group, f(QRS-T)a was significantly increased at T3, T4, T5, T6, T7, T8, and T9 time points when compared to the T1 value (P < 0.05, for all). On the other hand, fQRS-Ta was significantly higher in the NFA group than in the LFA group at T4, T5, and T6 time points. 

Conclusion: In our study, we have shown for the first time that NFA significantly increased the f(QRS-T)a, whereas LFA did not significantly increase the f(QRS-T)a except for immediately after the endotracheal intubation. It was also detected that f(QRS-T)a was significantly higher in the NFA group compared to that in the LFA group. Therefore, it can be concluded that LFA has more protective effects on myocardial repolarization than NFA.

Propofol prevents further prolongation of QT interval during liver transplantation

Here, we aimed to compare the effects of two anesthetic methods (desflurane inhalation anesthesia vs. propofol-based total intravenous anesthesia (TIVA)] on corrected QT interval (QTc) values during living donor liver transplantation. Altogether, 120 patients who underwent living donor liver transplantation were randomized to either the desflurane or TIVA group. The primary outcome was intraoperative QTc change. Other electrocardiogram, hemodynamic findings and postoperative outcomes were examined as secondary outcomes. QTc values were prolonged intraoperatively in both groups; however, the change was smaller in the TIVA group than in the desflurane group (P_{Group × Time} < 0.001). More patients had QTc values of > 500 ms in the desflurane group than in the TIVA group (63.3% vs. 28.3%, P < 0.001). In patients with preoperative QTc prolongation, QTc was further prolonged in the desflurane group, but not in the TIVA group (P_{Group × Time} < 0.001). Intraoperative norepinephrine and vasopressin use were higher in the desflurane group than in the TIVA group. Propofol-based TIVA may reduce QTc prolongation during living donor liver transplantation compared to that observed with desflurane inhalational anesthesia, particularly in patients with preoperative QTc prolongation. Additionally, patients managed with propofol-based TIVA required less vasopressor during the procedure as compared with those managed with desflurane inhalational anesthesia.

Effects of different concentrations of desflurane on the index of cardiac electrophysiological balance in gynecologic surgery patients

The objectives were to observe the effects of different concentrations of desflurane on QT, QTc, Tp-e, Tp-e/QT, and the index of cardiac electrophysiological balance (iCEB). Sixty patients were randomly divided into group D₁, group D₂, and group D₃ by using a random number table, 20 in each group. After entering the operating room, patients received 10 mL/kg hydroxyethyl starch, 0.1 mg/kg midazolam, 0.1 mg/kg vecuronium, 3 μg/kg fentanyl, and 0.3 mg/kg etomidate intravenously and then accepted intubation and mechanical ventilation. The desflurane evaporator was opened. The concentrations of desflurane in the D₁, D₂, and D₃ groups were maintained at 0.6, 1.3, and 2.0 minimum alveolar concentration (MAC), respectively. Twelve-lead ECGs were recorded at time before induction (T₁) and at 20 min after desflurane reached the required concentration (T₂). HR and MAP were recorded measure and the QT interval, QTc interval, Tp-e interval, Tp-e/QT ratio, and iCEB were calculated. Compared with before inhalation (T₁), the QTc interval was prolonged in the D₁, D₂, and D₃ groups after inhalation of different concentrations of desflurane for 20 min (T₂) (P < 0.05) and the Tp-e/QT ratio decreased in the D₁ and D₂ groups at T₂ (P < 0.05). Compared with the D₁ and D₂ groups, the Tp-e/QT ratio of the D₃ group increased at T₂ (P < 0.05). There was no significant difference in Tp-e interval and iCEB at any time (P > 0.05). The study suggested that inhalation of desflurane at a normal concentration cannot cause arrhythmogenic characteristics and affect the cardiac electrophysiological stability.

Effects of long periods of pneumoperitoneum combined with the head-up position on heart rate-corrected QT interval during robotic gastrectomy: an observational study

Objective

Pneumoperitoneum and the head-up position reportedly stimulate the sympathetic nervous system, potentially increasing the risk of cardiac arrhythmia. We evaluated the effects of a long duration of pneumoperitoneum in the head-up position on the heart rate-corrected QT (QTc) interval during robotic gastrectomy.

Methods

This prospective observational study involved 28 patients undergoing robotic gastrectomy. The QTc interval was recorded at the following time points: before anaesthetic induction (baseline); 10 minutes after tracheal intubation; 1, 5, 30, 60, and 90 minutes after pneumoperitoneum induction in the head-up position; after pneumoperitoneum desufflation in the supine position; and at the end of surgery. The primary outcome was the QTc interval, which was measured 90 minutes after pneumoperitoneum combined with the head-up position.

Results

Compared with baseline, the QTc interval was significantly prolonged at 1 and 60 minutes after pneumoperitoneum, peaked at 90 minutes, and was sustained and notably prolonged until the end of surgery. However, no considerable haemodynamic changes developed.

Conclusion

A long period of carbon dioxide pneumoperitoneum application in a head-up position significantly prolonged the QTc interval during robotic gastrectomy. Therefore, diligent care and close monitoring are required for patients who are susceptible to developing ventricular arrhythmia.

Trial Registration: Registered at ClinicalTrials.gov; https://clinicaltrials.gov/ct2/show/NCT02604979; Registration number NCT02604979

Comparative Pharmacology and Guide to the Use of the Serotonin 5-HT3 Receptor Antagonists for Postoperative Nausea and Vomiting

Since the introduction of the serotonin 5-hydroxy tryptamine 3 (5-HT₃) receptor antagonists in the early 1990s, the incidence of postoperative nausea and vomiting (PONV) and post-discharge nausea and vomiting (PDNV) has decreased, yet continues to be a problem for the surgical patient. The clinical application of the 5-HT₃ receptor antagonists has helped define the approach and role of these antiemetics in the prevention and treatment of PONV and PDNV. Pharmacological and clinical differences exist among these medications resulting in corresponding differences in effectiveness, safety, optimal dosage, time of administration, and use as combination and rescue antiemetic therapy. The clinical application of the 5-HT₃ receptor antagonist antiemetics has improved the prevention and treatment of PONV and PDNV. The most recent consensus guidelines for PONV published in 2014 outline the use of these antiemetics. The 5-HT₃ receptor antagonists play an important role to help prevent PONV and PDNV in perioperative care pathways such as Enhanced Recovery After Surgery (ERAS). Comparisons and guidelines for use of the 5-HT₃ receptor antagonists in relation to the risk for PONV and PDNV are reviewed.

Cardiac tachyarrhythmias and anaesthesia: General principles and focus on atrial fibrillation

Cardiac tachyarrhythmias are encountered commonly during the perioperative period and need to be promptly identified and appropriately managed by the anaesthesiologist. This review intends to highlight important aspects of these tachyarrhythmias and explore a temporal relationship between common medications employed in the perioperative period and their causation. Mechanisms of initiation of tachyarrhythmias, drugs that can trigger those, as well as their diagnosis and management, are also parts of the current review. Cardiac tachyarrhythmias may not always require treatment, and sometimes, aggressive management can trigger more serious types of arrhythmias. A thorough understanding of these tachyarrhythmias and their pathogenesis enables adopting a more objective approach, eschewing risks of inappropriate or unnecessary management strategies. We performed a MEDLINE search using combinations of MeSH terms such as ‘cardiac’, ‘arrhythmias’, ‘anaesthesia’, ‘perioperative’, ‘tachyarrhythmias’ and ‘anaesthetic implications’. We reviewed the relevant publications with regard to cardiac tachyarrhythmias occurring in the perioperative period.