Sevoflurane-induced arrhythmia in an adult and a child

Transient asystole associated with vasovagal reflex in an oral surgery patient: A case report

The perioperative cardiac events may be brought about by a relative imbalance of autonomic activities due to excessive psychological and physical stress. The present case study focuses on the asystole that can occur as a serious cardiac adverse event associated with vasovagal reflex likely to be triggered by venipuncture for securing an intravenous line during dental care. In addition, we describe and discuss herein the management of intravenous sedation for a dental phobic patient who experienced the vasovagal reflex involved in an unexpected transient asystole. The patient with vasovagal reflex episodes in daily life, who had no past medical history relevant to cardiovascular disorders, was scheduled for dental extraction under intravenous sedation. Immediately after peripheral intravenous catheterization, she complained of discomfort and nausea, and a II-lead electrocardiogram revealed asystole following bradycardia associated with vasovagal reflex. Oxygenation and intravenous fluid loading in the supine position with elevation of the lower extremities restored sinus rhythm and normal hemodynamics without the intervention of cardiopulmonary resuscitation. With administration of intravenous atropine and betamethasone as premedication, she was uneventfully treated in stress-free psychosomatic conditions under optimal sedation with midazolam without any signs of cardiovascular disorders. After administration of flumazenil, the patient satisfactorily recovered from sedation without re-sedation. The present case suggests that an asystole associated with vasovagal reflex can be triggered by venipuncture for intravenous catheterization during dental anxiety likely to affect the imbalance between sympathetic and parasympathetic activities.

Arrhythmia incidence and associated factors during volatile induction of general anesthesia with sevoflurane: a retrospective analysis of 950 adult patients

BACKGROUND

Sevoflurane has been used to induce anaesthesia in adults due to its suitability for airway management and haemodynamic stability. Few studies have reported arrhythmia during volatile induction with sevoflurane in adults. Here, we investigated the incidence of arrhythmia and risk factors associated with its occurrence during sevoflurane induction of anaesthesia in adults.

PATIENTS AND METHODS

We retrospectively analysed 950 adult patients who underwent elective ear nose and throat surgery with volatile induction using sevoflurane between May and December 2015. The incidence of arrhythmia and the factors associated with its development were analysed.

RESULTS

Arrhythmia was observed in 164 (17.3%) of 950 adult patients. The most frequently observed arrhythmia was sinus tachycardia (heart rate > 120 bpm) (77 patients, 47.0%). The multivariable logistic analysis showed four independent risk factors: age (odds ratio [OR] = 0.984, 95% confidence interval [CI] = 0.973-0.996, p = 0.006), coronary artery disease (OR = 3.749, 95% CI = 1.574-8.927, p = 0.003), maximal concentration (8 vol%) of sevoflurane from the start of induction (OR = 2.696, 95% CI = 1.139-6.382, p = 0.024), and maintenance of 8 vol% sevoflurane concentration after eyelash reflex loss (OR = 1.577, 95% CI = 1.083-2.296, p = 0.018). The risk of hypotension was greater in patients in whom arrhythmia occurred, although blood pressure recovered to baseline after the concentration of sevoflurane was adjusted.

CONCLUSIONS

We recommend that the sevoflurane concentration be gradually increased with continuous and vigilant electrocardiogram and blood pressure monitoring. The sevoflurane concentration should be adjusted after sufficient unconsciousness is reached.

Minimum Alveolar Concentration of Sevoflurane with Cisatracurium for Endotracheal Intubation in Neonates

Background

Sevoflurane inhalation induction is widely used in pediatric anesthesia, but the minimum alveolar concentration for endotracheal intubation (MAC_EI) when combined with neuromuscular blockade in neonates has been largely unexplored. This study assessed the MAC_EI of sevoflurane combined with cisatracurium in neonates.

Material/Methods

Anesthesia induction was commenced by inhaling 4% sevoflurane with 2 l/min of 100% oxygen via mask. Neonates were administered cisatracurium 0.2 mg/kg followed by adjustment of inspired sevoflurane to target end-tidal concentration based on intubation condition of the preceding subject. When the steady-state end-tidal sevoflurane concentration target was maintained for at least 15 min, endotracheal intubation by direct laryngoscope was performed. The intubation condition was considered failed if either heart rate (HR) after intubation increased by 20% or mean arterial blood pressure (MAP) by 30% or more than that before intubation. Otherwise, the intubation condition was regarded as successful. Dixon’s up-and-down method was used with 0.2% as the step size to determine the target end-tidal sevoflurane concentration.

Results

The MAC_EI of sevoflurane combined with cisatracurium in neonates was 2.76±0.24%. Using probit analysis, the 50% effective end-tidal sevoflurane concentration (ED₅₀) for successful condition of endotracheal intubation was 2.61% (95%CI 2.07–2.88%) and the 95% effective end-tidal sevoflurane concentration (ED₉₅) was 3.28% (95%CI 2.95–7.19%). Hypotension and bradycardia occurred in 2 neonates during induction.

Conclusions

Sevoflurane combined with cisatracurium is feasible and effective for intubation in neonates, and the MAC_EI of sevoflurane in this subpopulation is 2.76±0.24%. However, cardiovascular adverse effects should be taken into consideration.

Smartphones in the Operating Room: Distraction or Diagnostic Aid? A Case of Newly Diagnosed Wolff-Parkinson White in a Pediatric Patient Having Bronchoscopy Under General Anesthesia

A 4-year-old boy presented for elective bronchoscopy after years of pharmacologically unresponsive reactive airway disease that limited physical activity. After mask induction with nitrous oxide and sevoflurane, the patient was noted to be intermittently in a hemodynamically stable tachyarrhythmia. The anesthesia machine, though equipped with electrocardiogram (ECG) recording capabilities, malfunctioned during the case and was not able to print a rhythm strip. As a substitute, a smartphone picture and video were recorded. In the recovery room, initial 12-lead ECG showed sinus tachycardia. Shortly after, a presumptive diagnosis of Wolff-Parkinson White was given upon review of the smartphone recordings by the pediatric cardiologist on service. Twelve lead ECG was repeated which showed intermittent Wolff-Parkinson White. This case highlights 2 points. First, any prolonged or sustained pediatric dysrhythmia revealed during anesthesia warrants further investigation and should not be assumed secondary to an anesthetic drug. Second, ubiquitous smartphones are an excellent tool for capturing data that the monitor is unable to capture.