Bradycardia and cardiac asystole following a single injection of suxamethonium

Perioperative Implications of the 2020 American Heart Association Scientific Statement on Drug-Induced Arrhythmias-A Focused Review

The recently released American Heart Association (AHA) scientific statement on drug-induced arrhythmias discussed medications commonly associated with bradycardia, supraventricular tachycardias, and ventricular arrhythmias. The foundational data for this statement were collected from general outpatient and inpatient populations. Patients undergoing surgical and minimally invasive treatments are a unique subgroup, because they may experience hemodynamic changes associated with anesthesia and their procedure, receive multiple drug combinations not given in either inpatient or outpatient settings, or experience postprocedural inflammatory syndromes. Accordingly, the generalizability of the AHA scientific statement to this perioperative population is unclear. This focused review highlights important aspects of the new AHA scientific statement and their application to the perioperative setting. The authors review medications frequently encountered and given by anesthesiologists and their risk of drug-induced arrhythmias and discuss common anesthetic and adjunctive medications and their associated risks of bradycardia, atrial fibrillation, torsades de pointes, and drug-induced Brugada syndrome. In many instances, the risk of arrhythmia reported by the AHA scientific statement in the general population appeared to be higher than found in perioperative arenas. Furthermore, the authors discuss the arrhythmia risk of additional medications commonly ordered or administered by anesthesiologists that are not included in the AHA scientific statement. As patient and procedural complexity increases and novel anesthetic combinations propagate, further research and observational studies will be required to delineate further perioperative risks for drug-induced arrhythmia.

Guideline removal of atropine and survival after adult in-hospital cardiac arrest with a non-shockable rhythm

AIM

To determine whether the removal of atropine from the 2010 ACLS guidelines for non-shockable cardiac arrests was associated with a change in survival.

METHODS

Using the Get With The Guidelines^®-Resuscitation registry, we included adults with an index in-hospital cardiac arrest between 2006 and 2015. The primary outcome was survival to hospital discharge. Secondary outcomes included return of spontaneous circulation and favorable functional outcome. An interrupted time-series analysis was used to compare survival before (pre-guidelines) and after (post-guidelines) introduction of the 2010 guidelines. A difference-in-difference approach was used to compare the interrupted time-series results between the non-shockable and shockable cohorts to account for guideline changes unrelated to atropine.

RESULTS

We included 20,499 non-shockable and 3968 shockable cardiac arrests. Patient characteristics were similar between the pre-guidelines and post-guidelines period. Atropine was used for 8653 (87%) non-shockable and 680 (35%) shockable cardiac arrests in the pre-guidelines period and 3643 (35%) non-shockable and 320 (16%) shockable cardiac arrests in the post-guidelines period. The change over time in survival from the pre-guidelines to the post-guidelines period was not significantly different for the non-shockable compared to the shockable cohort (risk difference: 2.0% [95%CI: -0.8, 4.8] per year, p = 0.17). The immediate change in survival after introducing the guidelines was also not different between the cohorts (risk difference: 3.5% [95%CI: -2.6, 9.7], p = 0.26). Results were similar for the secondary outcomes and in multiple sensitivity analyses.

CONCLUSIONS

The removal of atropine from the 2010 guidelines was not associated with a significant change in survival.

Part 8: adult advanced cardiovascular life support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

The goal of therapy for bradycardia or tachycardia is to rapidly identify and treat patients who are hemodynamically unstable or symptomatic due to the arrhythmia. Drugs or, when appropriate, pacing may be used to control unstable or symptomatic bradycardia. Cardioversion or drugs or both may be used to control unstable or symptomatic tachycardia. ACLS providers should closely monitor stable patients pending expert consultation and should be prepared to aggressively treat those with evidence of decompensation.

Severe bradycardia during epilepsy surgery

Several kinds of arrhythmia are known to occur during epileptic seizure, and bradycardia has been reported in patients with temporal lobe epilepsy. The authors review the anesthesia records of patients with intractable epilepsy. Forty-two consecutive patients with intractable epilepsy who underwent epilepsy surgery were examined. Anterior temporal lobectomy was performed on 29 patients, frontal lobectomy on 2 patients, and a subdural electrode was set on 11 patients. Anesthesia was induced with propofol, fentanyl, and vecuronium and maintained with sevoflurane-fentanyl, propofol-fentanyl, or fentanyl-droperidol. Severe bradycardia (13-39 beats/min) was seen in six patients. All six patients recovered within 1 minute of interrupting the surgical procedure and administering intravenous atropine, and the surgeries were completed with no complications. The authors believe the six events were sinus bradycardias. They all occurred during amygdalo-hippocampectomy in cases of temporal lobectomy. This type of hemodynamic change was not seen in any of the patients undergoing temporal lobectomy without hippocampectomy, in patients undergoing frontal lobectomy, or when setting subdural electrodes. Experimentally, it has been shown that stimulation of the limbic system, such as the hippocampus, amygdala, and insular cortex, induces bradycardia and hypotension resulting from increased parasympathetic flow via the vagus nerve. Severe bradycardia may thus occur during surgery for temporal lobe epilepsy, and hemodynamic changes should be watched carefully during amygdalo-hippocampectomy.

Should the routine use of atropine before succinylcholine in children be reconsidered?

It is common practice to administer atropine before a first dose of succinylcholine in infants and children. However, the administration of succinylcholine without atropine has not been investigated in children. This study was designed to compare cardiovascular changes after the administration of either atropine with succinylcholine or succinylcholine alone. In 41 ASA I or II patients aged from 1 to 12 yr anaesthesia was induced with thiopentone 5 mg.kg-1. Patients were randomly allocated to receive either atropine 20 micrograms.kg-1 and succinylcholine 1.5 mg.kg-1 (n = 20) or succinylcholine 1.5 mg.kg-1 alone (n = 21). Heart rate and rhythm were recorded continuously from two minutes before induction until two minutes after tracheal intubation. Blood pressure was measured non-invasively before and after induction of anaesthesia and both immediately and two minutes after laryngoscopy. One self-limiting episode of bradycardia was recorded during laryngoscopy in a child who received atropine. Heart rate increased in both groups compared with baseline values (108 +/- 25), with a greater increase in patients who had received atropine (150 +/- 13) than in those who had not (128 +/- 18) (P < 0.05). There was no difference in mean arterial pressure or incidence of arrythmias between the two groups. No recorded arrythmias were judged to be clinically important by a cardiologist. The incidence of bradycardia after succinylcholine in the absence of atropine in children aged from 1 to 12 yr appears to be lower than previously estimated. The use of atropine before a single dose of succinylcholine in children deserves to be reconsidered.

The Australian Incident Monitoring Study. Cardiac arrest--an analysis of 2000 incident reports

Eighty-seven cases of cardiac arrest from the first 2000 incidents reported to the Australian Incident Monitoring Study were reviewed. "Cardiac arrest" was taken to include patients who were either pulseless or had electrocardiographic asystole or ventricular fibrillation. Cases were grouped by primary cause--drug administration (19), vagal stimulation (16), hypoventilation (15), bleeding (13), anaphylaxis (6), direct cardiac stimulation (4) and miscellaneous (14). Overall, 20 patients died (23% of the 87 cases); all of these were in the hypoventilation, bleeding, or miscellaneous groups (4, 9 and 7 patients, respectively). Cardiac compression was performed in 66% of patients; 20% were defibrillated; adrenaline was given to 42% and bicarbonate to 3%. There was a clear anaesthetic cause for 46% of this series of arrests, and with hindsight, a preventable factor was present in over half (58%) of these. Preventative strategies regarding staffing, equipment, policy and procedures are suggested.

Induction and recovery characteristics of desflurane in day case patients: a comparison with propofol

Desflurane is an ether halogenated exclusively with fluorine. It has a blood/gas partition coefficient of 0.42 (cf. isoflurane 1.40 and nitrous oxide 0.46). This characteristic suggests that it should provide both a fast induction of anaesthesia and a rapid recovery from anaesthesia. To assess this, 60 patients were entered into a study and allocated at random to one of four groups receiving either desflurane or propofol for induction and maintenance of anaesthesia. Desflurane caused loss of consciousness in approximately 2 minutes during gaseous inductions. The psychomotor scores in the patients who received propofol for induction and maintenance of anaesthesia were significantly worse compared with those who were given desflurane for either induction and maintenance or for maintenance only. There was also a tendency for other recovery parameters to be faster in the patients receiving desflurane although this did not reach statistical significance. This suggests that desflurane would be a suitable agent for day case anaesthesia providing for a rapid recovery.

[Cardiac arrest during anesthesia and recovery period]

Cardiac arrests (CA) occurring during anaesthesia and recovery can be classified into three groups: CA not related to anaesthesia (NACA), CA related to anaesthesia (ACA), whether partially (PACA) or totally (TACA). In the French survey, NACAs were three times more frequent than ACAs. Nearly 25% of ACAs occurred at induction and consisted mainly in TACAs. Another quarter of ACAs occurred during maintenance and consisted mainly in PACAs. About 50% of ACAs occurred after the end of anaesthesia and had the highest mortality rate. Cardiac arrest corresponds to the status of a heart unable to generate the minimum aortic blood flow required for functioning of vital organs. For the brain, a zero-blood flow of more than 4 seconds results in coma. Consequently CA exists when the time interval between two subsequent efficient systoles is greater than 4 seconds. Anaesthetic agents can result in CA by 1) overdose (absolute, relative), 2) anaphylactoid/anaphylactic reactions, 3) specific effects (acetylcholine-like effect, hyperkalaemia and malignant hyperthermia for succinylcholine; vagal effect of vecuronium and atracurium; cardiotoxicity of bupivacaine) and 4) drug interaction. In hypoxic CA, severe neurologic impairment often still exists at the time of onset of CA. The anaesthesia machine and controlled ventilation can induce CA by hypoxic ventilation, overdose of anaesthetic vapour, excessive CO2 reinhalation, hypoventilation, disconnection, excessive pressure in airways. Cardiac hypothermia can be a cause of CA as well as a cause of unsuccessful CPR. Massive infusion of unwarmed fluids and IPPV with unheated gases generate a temperature gradient within the heart which may result in severe arrhythmias and CA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adverse reactions and interactions of the neuromuscular blocking drugs

The adverse reactions seen following administration of neuromuscular blocking agents are mainly cardiovascular. Due to the lack of specificity for the nicotinic receptor at the neuromuscular junction, these agents may interact with receptors in autonomic ganglia and muscarinic receptors in the heart. Furthermore, muscle relaxants may have histamine-releasing properties. The cardiovascular effects vary with potency and specificity of the drug, depending mainly on the chemical structure. Pancuronium, fazadinium and especially gallamonium block cardiac muscarinic receptors, and tachycardia may be seen. Atracurium, metocurine and in particular d-tubocurarine have histamine-releasing properties and may cause flushing, hypotension and tachycardia. Vecuronium has no effect on the cardiovascular system. The effect of succinylcholine on heart rate differs between children, where bradycardia is seen, and adults in whom tachycardia may follow. However, bradycardia may occur in adults following a single dose. Succinylcholine increases plasma potassium, especially in patients with nerve damage, and arrhythmias may be observed. The neuromuscular adverse effects of succinylcholine, such as fasciculations and increased gastric and intraocular pressure, may be prevented by precurarisation. Many drugs interact with neuromuscular blocking agents and there is often a potentiation of the neuromuscular effect. This is of clinical importance in the case of antibiotics, inhalational anaesthetics, lithium and cyclosporin. Difficulty in reversing the block may occur with calcium channel blockers and polymyxin. However, some drugs, such as phenytoin, carbamazepine and lithium, may cause resistance to neuromuscular blocking agents. Furthermore, clinically important interactions exist between individual neuromuscular blocking drugs. Precurarisation with a non-depolarising drug prolongs the onset of succinylcholine, and conversely a prolonged effect of non-depolarising drugs is seen following succinylcholine. The effect of succinylcholine is markedly prolonged if the drug is administered during recovery from pancuronium blockade or following neostigmine for reversal. Succinylcholine is hydrolysed by plasma cholinesterase, and drugs which decrease the activity of this enzyme may produce a prolonged block, i.e. contraceptive pills, cyclophosphamide, echothiopate and organophosphate.

Sufentanil anaesthesia for major surgery: the multicentre Canadian clinical trial

One hundred and forty-one investigators from 45 institutions across Canada participated in the phase 4 clinical trial of sufentanil citrate involving 616 patients. All patients were ASA physical status class I, II, or III, undergoing elective, non-cardiac, major surgical procedures. The average duration of surgery was 1.98 hr and mean dosage of sufentanil was 1.24 micrograms.kg-1.hr-1. Supplemental inhalational anaesthesia was administered to 266 patients (43 per cent). Eighty-six patients required naloxone in the immediate postoperative period. Eighty per cent of these patients had received in excess of 1.0 microgram.kg-1.hr-1 of sufentanil. One hundred and twenty-nine adverse reactions were reported as disturbing and possibly drug-related. Profound bradycardia or sinus arrest was reported in four cases and disturbing hypotension in 37. None of these events required termination of the procedure. The induction, maintenance and recovery phases were rated as good or satisfactory by the participating investigators in 94, 92 and 93 per cent of cases respectively.

Vecuronium and phaeochromocytoma. A report of two cases using different modes of administration

Two patients presenting for removal of phaeochromocytoma are described. Vecuronium was used to provide neuromuscular blockade by two different methods of administration: an infusion and a large bolus dose. Both gave satisfactory results and we suggest that vecuronium may be the neuromuscular blocking agent of choice for patients with phaeochromocytoma.

The influence of fentanyl on the cardiovascular effect of suxamethonium

The influence of fentanyl on the cardiovascular effect of a single dose of suxamethonium was evaluated during thiopentone N2O/O2 anaesthesia. Sixty adult patients were randomly allocated to three groups. In one group (control group) no fentanyl was given. In two groups fentanyl 0.002 mg/kg and 0.004 mg/kg, respectively, was given before induction of anaesthesia. Three minutes after the injection of suxamethonium 1 mg/kg, both heart rate (HR) and mean arterial pressure (MAP) in the two groups receiving fentanyl were significantly lower than in the control group. However, the absolute changes were small and no dose-related effect was seen. An estimation of the change in HR following suxamethonium was made using as predictors initial HR before induction of anaesthesia, age, sex, and the injection of fentanyl. The higher the initial HR, the greater was the chance of a decrease in HR following suxamethonium. Injection of fentanyl lowered the threshold HR above which a decrease was to be expected following injection of suxamethonium. This effect was most pronounced among the younger patients. It is concluded that injection of fentanyl potentiates the decrease in HR sometimes seen after a single dose of suxamethonium and that this effect is influenced by HR before induction of anaesthesia and by age of the patient.

Asystole and bradycardia in adult patients after a single dose of suxamethonium

Two cases of cardiac asystole and one case of severe bradycardia were seen following a single injection of suxamethonium in a series of 46 adult patients in whom anaesthesia was induced with fentanyl and etomidate. It is suggested that the vagomimetic effects of fentanyl and, possibly also of etomidate, may contribute to the enhancement of the bradycardic effects of suxamethonium.

High-dose fentanyl for rapid induction of anaesthesia in patients with coronary artery disease

Nine premedicated patients, chronically maintained on beta-adrenergic blocking agents and demonstrating good ventricular function without significant valvular or left main coronary artery disease, were investigated to determine their haemodynamic responses to rapid induction of anaesthesia and tracheal intubation during elective coronary artery bypass surgery. Fentanyl 50 micrograms X kg-1 and pancuronium 0.15 mg X kg-1 were administered intravenously over 20 seconds followed by tracheal intubation 90 seconds thereafter. The rapid sequence of anaesthetic induction and tracheal intubation was well tolerated by all patients. Though statistically significant changes were detected in heart rate, pulmonary capillary wedge pressure and systemic vascular resistance, these changes were small and not considered clinically significant and no signs of ischaemia were detected on the ECG. The present study demonstrates that high-dose fentanyl is capable of inducing anaesthesia rapidly and protecting against the haemodynamic changes associated with tracheal intubation.

Changes in heart rate and impulse conduction after a single dose of succinylcholine

The effect of 1 and 2 mg/kg b.w. succinylcholine on changes in cardiac rate and rhythm was studied in 40 fit, adult patients undergoing non-emergency surgery. Induction of anaesthesia consisted of atropine 0.007 mg/kg b.w., pancuronium 0.015 mg/kg b.w., thiopental 5 mg/kg and succinylcholine 1 or 2 mg/kg b.w. Succinylcholine 1 mg/kg b.w. intravenously resulted in a significant decrease in heart rate after 1 min. This decrease persisted after 2 min. The heart rate was unchanged 1 and 2 min after succinylcholine 2 mg/kg b.w. When the two groups were compared, no significant difference was found. No serious cardiac arrhythmias were seen. These results suggest that the larger single dose of succinylcholine is not more likely to cause severe bradycardia or asystole.