The Influence of desflurane on QTc interval

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.

The effects of intravenous anesthetics on QT interval during anesthetic induction with desflurane

Introduction

This study aimed to determine the effects of the interaction between intravenous anesthetics and desflurane on the QT interval.

Methods

Fifty patients who underwent lumbar spine surgery were included. The patients received 3 μg/kg fentanyl and were randomly divided into two groups: group P patients received 1.5 mg/kg propofol and group T patients received 5 mg/kg thiamylal 2 min after fentanyl injection. All patients received rocuronium and desflurane (6% inhaled concentration) after loss of consciousness. Tracheal intubation was performed 3 min after rocuronium injection. Heart rate (HR), mean arterial pressure (MAP), bispectral index score (BIS), and the heart rate-corrected QT (QTc) interval on a 12-lead electrocardiograms were recorded before fentanyl injection (T1), 2 min after fentanyl injection (T2), 1 min after propofol or thiamylal injection (T3), immediately before intubation (T4), and 2 min after intubation (T5).

Results

There were no significant intergroup differences in patient characteristics. BIS and MAP decreased after anesthesia induction in both groups. MAP values at T3, T4, and T5 in group T were higher than those in group P. HR did not change over time or differ between the groups. The QTc intervals at T4 and T5 in group T were longer than those at T1. In group P, the QTc interval at T3 was significantly shorter than that at T1. The QTc intervals at T3, T4, and T5 in group T were significantly longer than those in group P.

Conclusions

A propofol injection could counteract the QTc interval prolongation during desflurane anesthesia induction.

Trial registration

UMIN Clinical Trials Registry database reference number: UMIN000023707. This study was registered on August 21, 2016.

Effects of Dexmedetomidine on Changes in Heart Rate Variability and Hemodynamics During Tracheal Intubation

Sympathetic hyperactivation during tracheal intubation prolongs the QT interval and increases the risk of arrhythmias. We investigated if dexmedetomidine pretreatment affected autonomic nervous system balance and QT intervals during intubation. Sixty-six patients were randomized to receive 1.0 μg/kg fentanyl (group F, n = 22), 0.5 μg/kg dexmedetomidine (group D0.5, n = 22), or 1.0 μg/kg dexmedetomidine (group D1.0, n = 22) before induction. Autonomic nervous system balance was assessed by the ratio of low-frequency/high-frequency (LF/HF) power for heart rate variability at baseline (T0), before intubation (T1), and after intubation (T2). QT intervals were corrected by the Bazett's formula (QTc) and compared at baseline, before intubation, and 1, 2, and 3 minutes after intubation. The LF/HF ratio was higher after intubation compared with that at T0 in group F (P < 0.001). There were no significant changes in groups D0.5 and D1.0. The LF/HF ratio was significantly higher in group F compared with those in groups D0.5 and D1.0 after intubation (7.9 vs. 2.1 and 2.5; P < 0.001). The heart rate was increased for 3 minutes after intubation in group F, whereas only for 1 minute after intubation in groups D0.5 and D1.0, compared with that at baseline. More patients in group F had QTc greater than 440 ms compared with that in group D0.5 or D1.0 (8 vs. 1 and 2; P = 0.005) at 1 minute after intubation. In contrast to 1.0 μg/kg fentanyl, pretreatment with 0.5 or 1.0 μg/kg dexmedetomidine suppressed sympathetic hyperactivity and attenuated QTc prolongation during intubation.

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

BACKGROUND

QT interval prolongation has frequently been observed in patients with advanced liver disease. We investigated the influence of inhalation anesthetics on the corrected QT (QTc) interval prolongation during surgery in patients undergoing living-donor liver transplantation.

METHODS

Our study included 43 patients who were assigned to 2 groups: sevoflurane (n = 22) or desflurane anesthesia (n = 21). QTc intervals were measured at perioperative determined time points and calculated using Fridericia's formula.

RESULTS

Intraoperative QTc intervals increased during the peri-intubation period versus baseline (P = .003) and were prolonged during the peri-reperfusion period (P < .001). However, there was no significant difference in intraoperative QTc interval changes between patients given sevoflurane or desflurane (P = .59).

CONCLUSIONS

In this prospective observational study, there was no significant difference in QTc intervals between sevoflurane and desflurane. QTc intervals increased during intubation and reperfusion relative to preoperative values in patients given either sevoflurane or desflurane.

Effect of ramosetron on QTc interval: a randomised controlled trial in patients undergoing off-pump coronary artery bypass surgery

Background

Ramosetron is a relatively new 5-hydroxytryptamine three receptor antagonist with higher binding affinity and more prolonged duration of action compared to ondansetron. The present study was performed to evaluate the effects of ramosetron on QTc interval and possible cardiovascular adverse effects in patients undergoing cardiac surgery.

Method

A total of 114 patients who underwent off-pump coronary artery bypass surgery were enrolled in this randomised placebo-controlled trial. Patients were allocated into two groups that received intravenous injection of 0.3 mg ramosetron or normal saline during induction of anaesthesia. QTc intervals were measured before the operation, intraoperatively (0, 1, 2, 3, 5, 10, 15, 30, 45, 60, 90, 120, and 240 min after injection of ramosetron or normal saline), at the end of the operation, and on postoperative day 1.

Results

There were no differences in mean QTc interval between groups at every time point. However, maximal change in QTc interval during surgery was higher in the ramosetron group than the placebo group (25.1 ± 22.0 vs. 17.5 ± 14.5 ms, 95 % CI 0.34–14.78, P = 0.040). Also, there were more patients with a QTc interval increase of > 60 ms in the ramosetron group (5 vs. 0, 95 % CI 1.6–18.0, P = 0.021). There were no significant differences in cardiovascular complications.

Conclusions

Ramosetron administered during induction of anaesthesia may affect maximal change in QTc interval during off-pump coronary artery bypass surgery. Ramosetron should be used with caution in high risk patients for developing Torsades de Pointes.

Trial registration

ClinicalTrials.gov NCT02139241. Registered November 12, 2013

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-016-0222-1) contains supplementary material, which is available to authorized users.

Safe Anaesthesia Management in a Child with Congenital Long QT Syndrome

Long QT syndrome is a cardiac repolarisation disorder that can occur with clinical symptoms such as dizziness, fainting, life-threatening arrhythmias and sudden cardiac death, and its incidence is increasing in the general population. A careful anaesthetic management is required for patients with this syndrome because of the risk of torsades de pointes and malignant arrhythmias. In this case report, we discuss the anaesthetic management of a seven-year-old patient with congenital long QT syndrome that was diagnosed during the preoperative evaluation.

Effects of Palonosetron on Perioperative Cardiovascular Complications in Patients Undergoing Noncardiac Surgery With General Anesthesia: A Retrospective Cohort Study

We retrospectively investigated whether palonosetron administered during the induction of general anesthesia is associated with an increased risk of perioperative cardiovascular complications in a single tertiary center cohort consisting of 4,517 palonosetron-exposed patients and 4,517 propensity score-matched patients without palonosetron exposure. The primary endpoint was a composite of perioperative cardiovascular complications, including intraoperative cardiac arrhythmia, intraoperative cardiac death, and myocardial injury within the first postoperative week, and there was no significant difference between the groups (odds ratio [OR] = 1.04; 95% confidence interval [CI] = 0.92-1.19). As secondary endpoints, intraoperative cardioversion, cardiac compression, use of cardiovascular drugs, postoperative hospital stay, and in-hospital mortality showed no differences between the groups. However, the palonosetron group showed decreased intraoperative hypotension (OR = 0.88; 95% CI = 0.79-0.97) and length of postoperative intensive care unit (ICU) stay (4.26 ± 9.86 vs. 6.14 ± 16.75; P = 0.026). Palonosetron did not increase the rate of perioperative cardiovascular complications, and can therefore be used safely during anesthetic induction.

Drugs to be avoided in patients with long QT syndrome: Focus on the anaesthesiological management

Long QT syndrome incidence is increasing in general population. A careful pre-, peri- and post-operative management is needed for patients with this syndrome because of the risk of Torsades de Pointes and malignant arrhythmias. The available data regarding prevention of lethal Torsades de Pointes during anesthesia in patients with long QT syndrome is scant and conflicting: only case reports and small case series with different outcomes have been published. Actually, there are no definitive guidelines on pre-, peri- and post-operative anesthetic management of congenital long QT syndrome. Our review focuses on anesthetic recommendations for patients diagnosed with congenital long QT syndrome furnishing some key points for preoperative optimization, intraoperative anesthetic agents and postoperative care plan, which could be the best for patients with c-long QT syndrome who undergo surgery.

Sex and gender aspects in anesthetics and pain medication

The influence of sex and gender on anesthesia and analgesic therapy remains poorly understood, nevertheless the numerous physiological and pharmacological differences present between men and women. Although in anesthesiology sex-gender aspects have attracted little attention, it has been reported that women have a greater sensitivity to the non-depolarizing neuroblocking agents, whereas males are more sensitive than females to propofol. It has been suggested that men wake slower than women after general anesthesia and have less postoperative nausea and vomiting. Sexual hormones seem to be of importance in the onset of differences. Nevertheless, in the last years, sex-gender influences on pain and analgesia have become a hot topic and data regarding sex-gender differences in response to pharmacologic and non-pharmacologic pain treatments are still scanty, inconsistent, and non-univocal. In particular, females seem to be more sensitive than males to opioid receptor agonists. Women may experience respiratory depression and other adverse effects more easily if they are given the same doses as males. Evidently, there is an obvious need for more research, which should include psychological and social factors in experimental preclinical and clinical paradigms in view of their importance on pain mechanism, in order to individualize analgesia to optimize pain relief.

Perioperative management of hereditary arrhythmogenic syndromes

Patients with inherited cardiac channel disorders are at high risk of perioperative lethal arrhythmias. Preoperative control of symptoms and a multidisciplinary approach are required for a well-planned management. Good haemodynamic monitoring, adequate anaesthesia and analgesia, perioperative maintenance of normocarbia, normothermia, and normovolaemia are important. In congenital long QT syndrome, torsades de pointes should be prevented with magnesium sulphate infusion and avoidance of drugs such as droperidol, succinylcholine, ketamine, and ondansetron. Propofol and epidural anaesthesia represent safe choices, while caution is needed with volatile agents. In Brugada syndrome, β-blockers, α-agonists, and cholinergic drugs should be avoided, while isoproterenol reverses the ECG changes. Propofol, thiopental, and volatiles have been used uneventfully. In congenital sick sinus syndrome, severe bradycardia resistant to atropine may require isoproterenol or epinephrine. Anaesthetics with vagolytic properties are preferable, while propofol and vecuronium should be given with caution due to risk of inducing bradyarrhythmias. Neuraxial anaesthesia should produce the least autonomic imbalance. Arrhythmogenic right ventricular dysplasia/cardiomyopathy induces ventricular tachyarrhythmias, which should be treated with β-blockers. Generally, β-adrenergic stimulation and catecholamine release should be avoided. Halothane and pancuronium are contraindicated, while large doses of local anaesthetics and epinephrine should be avoided in neuraxial blocks. In catecholaminergic polymorphic ventricular tachycardia, β-blocker treatment should be continued perioperatively. Catecholamine release and β-agonists, such as isoproterenol, should be avoided. Propofol and remifentanil are probably safe, while halothane and pancuronium are contraindicated. Regional anaesthesia, without epinephrine, is relatively safe. In suspicious cardiac deaths, postmortem examination and familial screening are recommended.

Ionic mechanisms of desflurane on prolongation of action potential duration in rat ventricular myocytes

PURPOSE

Despite the fact that desflurane prolongs the QTC interval in humans, little is known about the mechanisms that underlie these actions. We investigated the effects of desflurane on action potential (AP) duration and underlying electrophysiological mechanisms in rat ventricular myocytes.

MATERIALS AND METHODS

Rat ventricular myocytes were enzymatically isolated and studied at room temperature. AP was measured using a current clamp technique. The effects of 6% (0.78 mM) and 12% (1.23 mM) desflurane on transient outward K⁺ current (I(to)), sustained outward current (I(sus)), inward rectifier K⁺ current (I(KI)), and L-type Ca²⁺ current were determined using a whole cell voltage clamp.

RESULTS

Desflurane prolonged AP duration, while the amplitude and resting membrane potential remained unchanged. Desflurane at 0.78 mM and 1.23 mM significantly reduced the peak I(to) by 20 ± 8% and 32 ± 7%, respectively, at +60 mV. Desflurane (1.23 mM) shifted the steady-state inactivation curve in a hyperpolarizing direction and accelerated inactivation of the current. While desflurane (1.23 mM) had no effects on I(sus) and I(KI), it reduced the L-type Ca²⁺ current by 40 ± 6% (p<0.05).

CONCLUSION

Clinically relevant concentrations of desflurane appear to prolong AP duration by suppressing I(to) in rat ventricular myocytes.

[Long QT syndrome and anaesthesia]

The long QT syndrome (LQTS) is a rare, congenital or acquired disease, which may lead to fatal cardiac arrhythmias (torsade de pointes, TdP). In all LQTS subtypes, TdPs are caused by disturbances in cardiac ion channels. Diagnosis is made using clinical, anamnestic and electrocardiographic data. Triggers of TdPs are numerous and should be avoided perioperatively. Sufficient sedation and preoperative correction of electrolyte imbalances are essential. Volatile anaesthetics and antagonists of muscle relaxants should be avoided and high doses of local anaesthetics are not recommended to date. Propofol is safe for anaesthesia induction and maintenance. The acute therapy of TdPs with cardiovascular depression should be performed in accordance with the guidelines for advanced cardiac life support and includes cardioversion/defibrillation and magnesium. Torsades de pointes may be associated with bradycardia or tachycardia resulting in specific therapeutic and prophylactic measures.

Effect of anaesthetic agents on p-wave dispersion on the electrocardiogram: comparison of propofol and desflurane

Anaesthetics influence cardiac electrical activity by various mechanisms; thus, they may have pro-arrhythmic or anti-arrhythmic actions. Increased P-wave dispersion is associated with a risk of paroxysmal atrial fibrillation. The aim of the present study was to analyse the impact of propofol and desflurane on changes in P wave dispersion, which may reflect the anti-arrhythmic effects of these drugs. Fifty patients undergoing scheduled surgery were included in the study. Patients were divided into two equal groups: a propofol group and a desflurane group. Patients in the propofol group were initially administered 2.5 mg/kg propofol, followed by infusion of 6 mg/kg per h propofol. Anaesthesia in the desflurane group was achieved using inhalation induction, with concentrations up to 8-12.5 vol%. When signs of adequate anaesthesia were observed, the concentration of desflurane was reduced to 6 vol%. An electrocardiogram (ECG) was obtained before induction and then again 1, 3 and 5 min after the initiation of propofol infusion or the induction of anaesthesia in the desflurane group; additional measurements were performed after tracheal intubation. P-wave dispersion was assessed by differences in maximal and minimal P-wave duration on a 12-lead ECG. P-wave dispersion did not change over time in the desflurane group. In the propofol group, there was a significant decrease in P-wave dispersion after 3 and 5 min of anaesthesia. Significant differences were observed between study groups after 1, 3 and 5 min of anaesthesia, and disappeared after tracheal intubation. Mean and maximal P-wave duration did not change in either group. In conclusion, propofol decreases P-wave dispersion and this seems to be connected with the anti-arrhythmic properties of the drug.

Brief review: anesthetic implications of long QT syndrome in pregnancy

PURPOSE

To review the effects of the long QT syndrome (LQTS) in the parturient and the current anesthetic management of patients with LQTS.

SOURCE

Relevant articles were obtained from a MEDLINE search spanning the years 1980-2006 and a PubMed search spanning the years 1949-2006. Bibliographies of retrieved articles were searched for additional articles.

PRINCIPAL FINDINGS

The prevalence of LQTS in the developed world is one per 1,100 to 3,000 of the population. Clinically, LQTS is characterized by syncope, cardiac arrest and occasionally, by a history of seizures. The QT interval can also be prolonged by drugs, electrolyte imbalances, toxins and certain medical conditions. Long QT syndrome patients are at risk of torsades de pointes and ventricular fibrillation. Medical management aims to reduce dysrhythmia frequency. The LQTS is subdivided into different groups (LQT1-6) depending on the cardiac ion channel abnormality. Torsades can be precipitated by adrenergic stimuli such as stress or pain (LQT1 and 2), sudden noises (LQT2) or whilst sleeping (LQT3). Patients with LQTS require careful anesthetic management as they are at high risk of torsades perioperatively despite minimal data on the effects of anesthetic agents on the QT interval. While information on effects of LQTS in pregnancy is limited, the incidence of dysrhythmia increases postpartum. Isolated case reports of patients with LQTS women highlight several peripartum dysrhythmias.

CONCLUSION

An understanding of LQTS and the associated risk factors contributing to dysrhythmias is important for anesthesthesiologists caring for parturients with LQTS.

The effects of sevoflurane and desflurane anesthesia on QTc interval and cardiac rhythm in children

BACKGROUND

Inhalational anesthetics may prolong QTc interval (QT interval corrected for heart rate) of the ECG and cause life-threatening arrythmias. The effects of desflurane on QTc interval and cardiac rhythm have not been reported previously in children. We assessed the effects of desflurane anesthesia on QTc interval and cardiac rhythm and compared them with sevoflurane anesthesia in children.

METHODS

The study was performed on 20 children admitted for inguinal hernia repair, with normal QTc intervals. Anesthesia was induced with propofol and intubation was achieved with vecuronium. Anesthesia was maintained with 2% sevoflurane (group I, n = 11) or 6% desflurane (group II, n = 9) and 66% nitrous oxide in oxygen. Electrocardiogram recordings were obtained by Holter recorder. QTc intervals were measured at baseline, 5, 10, 15, and 30 min after inhalation.

RESULTS

None of the patients had significant arrythmia with desflurane anesthesia. One patient in the sevoflurane group had single, bigemini and multiform ventricular extrasystoles. There was no statistically significant difference in the baseline QTc values of the groups. Desflurane significantly prolonged QTc interval 5 min after induction until 30 min of anesthesia compared with baseline values (P = 0.029), while no significant prolongation was observed with sevoflurane (P = 0.141).

CONCLUSIONS

Use of 2% sevoflurane during maintenance of anesthesia does not significantly prolong QTc interval while 6% desflurane significantly prolonged QTc interval in children with normal QTc interval undergoing inguinal herniorrhaphy.

A life-threatening complication of the arterial tourniquet in Timothy syndrome

An infant with Timothy syndrome, a congenital syndrome resulting in a long QT interval and high risk of death in childhood, is presented along with his perioperative management. Characteristic life-threatening arrhythmias thought to be caused by excess sympathetic stimulation secondary to an arterial tourniquet are described.