Sedation in the Electrophysiology Laboratory: A Multidisciplinary Review

Management of anesthesia for procedures in the cardiac electrophysiology laboratory

The complexity of cardiac electrophysiology procedures has increased significantly during the past 3 decades. Anesthesia requirements of these procedures can differ on the basis of patient- and procedure-specific factors. This manuscript outlines various anesthesia strategies for cardiac implantable electronic devices and electrophysiology procedures, including preprocedural, procedural, and postprocedural management. A team-based approach with collaboration between cardiac electrophysiologists and anesthesiologists is required with careful preprocedural and intraprocedural planning. Given the recent advances in electrophysiology, there is a need for specialized cardiac electrophysiology anesthesia care to improve the efficacy and safety of the procedures.

Etiologies, Mechanisms, Management, and Outcomes of Electrical Storm

Electrical storm (ES) is characterized by three or more discrete sustained ventricular tachyarrhythmia episodes occurring within a limited time frame (generally ≤ 24 h) or an incessant ventricular tachyarrhythmia lasting > 12 h. In patients with an implantable cardioverterdefibrillator (ICD), ES is defined as three or more appropriate device therapies, separated from each other by at least 5 min, which occur within a 24-h period. ES may constitute a medical emergency, depending on the number arrhythmic episodes, their duration, the type, and the cycle length of the ventricular arrhythmias, as well as the underlying ventricular function. This narrative review was facilitated by a search of MEDLINE to identify peer-reviewed clinical trials, randomized controlled trials, meta-analyses, and other clinically relevant studies. The search was limited to English-language reports published between 1999 and 2023. ES was searched using the terms mechanisms, genetics, channelopathies, management, pharmacological therapy, sedation, neuraxial modulation, cardiac sympathetic denervation, ICDs, and structural heart disease. Google and Google scholar as well as bibliographies of identified articles were reviewed for additional references. This manuscript examines the current strategies available to treat ES and compares pharmacological and invasive treatment strategies to diminish ES recurrence, morbidity, and mortality.

Laryngeal mask airway versus endotracheal intubation as general anesthesia airway managements for atrial fibrillation catheter ablation: a comparative analysis based on propensity score matching

BACKGROUND

The current evidence on the use of laryngeal mask airway (LMA) as an airway management technique for general anesthesia (GA) during atrial fibrillation (AF) catheter ablation (CA) is insufficient. This study aims to compare the feasibility, safety, and clinical benefits of LMA and endotracheal intubation (ETI) for airway management in AF CA.

METHODS

One hundred fifty-two consecutive patients with AF who underwent CA under GA were included and divided into two groups based on different airway management methods (66 in the LMA group, 86 in the ETI group). After propensity score matching, a final analysis cohort of 132 patients was obtained to compare procedural parameters, adverse events, and prognosis between the two groups.

RESULTS

The LMA group exhibited significantly shorter total procedural time (p = 0.039), anesthesia induction time (p = 0.015), and recovery time (p = 0.006) compared to the ETI group. The mean arterial pressure (MAP) and heart rate were significantly lower in the LMA group during extubation and 1-min post-extubation (p < 0.05). Furthermore, the LMA group demonstrated lower MAP levels during intubation (p = 0.029). The incidences of intraoperative hypotension (p = 0.017) and bradycardia (p = 0.032) were significantly lower in the LMA group. The incidences of delayed recovery or delirium (p = 0.027), laryngeal or airway injury (p = 0.016), cough or bucking (p = 0.001), and sore throat (p < 0.001) were significantly lower in the LMA group. There were no statistically significant differences in catheter stability parameters and sinus rhythm maintenance rates between the two groups (p > 0.05).

CONCLUSION

LMA is feasible, safe, and effective in AF CA as an optimized airway management technique for GA.

Feasibility and Accuracy of Noninvasive Continuous Arterial Pressure Monitoring during Transcatheter Atrial Fibrillation Ablation

Introduction: Transcatheter atrial fibrillation (AF) ablation is still carried out with continuous invasive radial arterial blood pressure (IBP) monitoring in many centers. Continuous noninvasive blood pressure (CNBP) measurement using the volume-clamp method is a noninvasive alternative method used in ICU. No data on CNBP reliability are available in the electrophysiology lab during AF ablation, where rhythm variations are common. Background: The objective of the present study was to compare continuous noninvasive arterial pressure measured with the ClearSight device (Edwards Lifesciences, Irvine, CA, USA) with invasive radial artery pressure used as the reference method during AF ablation. Methods: We prospectively enrolled 55 consecutive patients (age 62 ± 11 years, 80% male) undergoing transcatheter AF ablation (62% paroxysmal, 38% persistent) at our center. Standard of care IBP monitoring via a radial cannula and a contralateral noninvasive finger volume-clamp CNBP measurement device were positioned simultaneously in all patients for the entire procedure. Bland-Altman analysis was used to analyze the agreement between the two techniques. Results: A total of 1219 paired measurements for systolic, diastolic, and mean arterial pressure were obtained in 55 subjects, with a mean (SD) of 22 (9) measurements per patient. The mean bias (SD) was −12.97 (13.89) mmHg for systolic pressure (level of agreement −14.24–40.20; correlation coefficient 0.84), −1.85 (8.52) mmHg for diastolic pressure (level of agreement −18.54–14.84; correlation coefficient 0.77) and 2.31 (8.75) mmHg for mean pressure (level of agreement −14.84–19.46; correlation coefficient 0.85). Conclusion: In patients undergoing AF ablation, CNBP monitoring with the ClearSight device showed acceptable agreement with IBP monitoring. Larger studies are needed to confirm the potential clinical implications of continuous noninvasive BP monitoring during AF ablation.

Propofol dose and efficacy of defibrillation testing during implantation of subcutaneous implantable cardioverter-defibrillators: A retrospective, single center cohort study

INTRODUCTION

Defibrillation testing (DFT) is recommended during subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation. Previous studies analyzing the potential interference of propofol with defibrillation threshold are inconsistent. The purpose of this study was to analyze whether propofol affects DFT post S-ICD placement.

METHODS

All patients with S-ICD implantation between 01/2017 and 11/2020 at the University Heart Center Freiburg were retrospectively analyzed. Two groups were generated depending on the success of the first shock during DFT. Implantation characteristics and dose of anesthetics were analyzed.

RESULTS

In 12 of the included 80 (15%) patients, first shock during DFT failed. The absolute dose of propofol was significantly higher in patients with first shock failure (median 653 mg [IQR 503-855]) compared to patients with first shock termination (376 mg [200-600]; p = 0.027). Doses of opioids and midazolam as well as type of anesthesia did not differ between the groups. A multivariable binary logistic regression analysis confirmed an independent association of first shock termination and propofol dose (per 100 mg: OR 0.73 (95% CI: 0.56-0.95); p = 0.021).

CONCLUSION

There is an independent association of propofol dose and first shock failure in routine S-ICD defibrillation testing.

Catheter ablation for atrial fibrillation can be safely performed without invasive hemodynamic monitoring: A multi-center study

BACKGROUND

Arterial invasive monitoring is the most common method in the USA for hemodynamic monitoring during atrial fibrillation (AF) ablation. Although studies have shown favorable comparison between non-invasive and invasive hemodynamic monitoring (IHM) in non-cardiac procedures under general anesthesia, limited data is available for complex cardiac procedures such as AF ablation in the USA. With progressive improvement in AF ablation procedural safety, particularly with routine use of intracardiac echocardiography (ICE) to monitor for pericardial effusion, it is unclear if invasive hemodynamic monitoring provides any advantage over non-invasive methods. Therefore, the purpose of this study is to determine whether noninvasive hemodynamic monitoring is non-inferior to invasive hemodynamic monitoring during AF ablation under general anesthesia in patients without major cardiac structural abnormality.

METHODS

A multi-center retrospective data of AF ablation from July 2019 to December 2020 was extracted. A total of three hundred and sixty-two patients (362) were included, which were divided into group A (non-invasive hemodynamic monitoring) and group B (invasive hemodynamic monitoring). The primary outcome was to compare procedural safety between the two groups.

RESULTS

Out of 362 patients, 184 (51%) received non-invasive and 178 (49%) received invasive hemodynamic monitoring with similar baseline characteristics. There was no significant difference between the two groups in complication rates (groin hematoma, pericardial effusion, cardiac tamponade). Mean procedure time was longer in group B with 3.35% arterial site discomfort. Urgent arterial access was required in only 1 patient in group A.

CONCLUSION

This retrospective multicenter study strongly suggests that catheter ablation for atrial fibrillation under general anesthesia can be safely performed with noninvasive hemodynamic monitoring without requiring arterial access, with potential benefit in procedural duration and cost.

High-flow nasal oxygenation reduces the risk of desaturation in adults receiving procedural sedation: a meta-analysis of randomized controlled trials

Background

Procedural sedation reduces patients’ discomfort and anxiety, facilitating performance of the examination and intervention. However, it may also cause adverse events, including airway obstruction and hypoxia. We conducted this systematic review and meta-analysis to evaluate the efficacy of high-flow nasal oxygenation (HFNO) compared with that of standard oxygen therapy in adult patients undergoing procedural sedation.

Methods

We identified randomized controlled trials published before November 2020 based on PubMed, Embase, and Cochrane Library databases and ClinicalTrials.gov registry. Intraprocedural desaturation [peripheral oxygen saturation (SpO₂) < 90%] was evaluated as the primary outcome. The secondary outcomes were the lowest SpO₂, need for airway intervention, oxygen therapy-related complications, and patient, operator, and anesthetist’s satisfaction.

Results

Six trials with a total of 2633 patients were reviewed. Patients using HFNO compared with standard oxygen therapy had a significantly lower risk of intraprocedural desaturation [risk ratio 0.18, 95% confidence interval (CI) 0.04-0.87]. The lowest intraprocedural SpO₂ in HFNO group was significantly higher than that in standard oxygen therapy group (mean difference 4.19%, 95% CI 1.74-6.65).

Conclusions

Compared with standard oxygen therapy, HFNO may reduce the risk of desaturation and increase the lowest SpO₂ in adult patients undergoing sedation for medical procedures.

The Practice of Deep Sedation in Electrophysiology and Cardiac Pacing Laboratories: Results of an Italian Survey Promoted by the AIAC (Italian Association of Arrhythmology and Cardiac Pacing)

The aim of this survey, which was open to all Italian cardiologists involved in arrhythmia, was to assess common practice regarding sedation and analgesia in interventional electrophysiology procedures in Italy. The survey consisted of 28 questions regarding the approach to sedation used for elective direct-current cardioversion (DCC), subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation, atrial fibrillation (AF) ablation, ventricular tachycardia (VT) ablation, and transvenous lead extraction procedures. A total of 105 cardiologists from 92 Italian centres took part in the survey. The rate of centres where DCC, S-ICD implantation, AF ablation, VT ablation and lead extraction procedures were performed without anaesthesiologic assistance was 60.9%, 23.6%, 51.2%, 37.3%, and 66.7%, respectively. When these procedures were performed without anaesthesiologic assistance, the drugs (in addition to local anaesthetics) commonly administered were benzodiazepines (from 64.3% to 79.6%), opioids (from 74.4% to 88.1%), and general anaesthetics (from 7.1% to 30.4%). Twenty-three (21.9%) of the 105 cardiologists declared that they routinely administered propofol, without the supervision of an anaesthesiologist, in at least one of the above-mentioned procedures. In current Italian clinical practice, there is a lack of uniformity in the sedation/analgesia approach used in interventional electrophysiology procedures.

Parallel Mapping and Catheter Ablation of Polymorphic Premature Ventricular Contractions: A New Feature for Activation Mapping

We report the case of an 80-year-old female presenting with polymorphic premature ventricular contractions, nonischemic cardiomyopathy, and severe, secondary mitral regurgitation. Despite a low intraprocedural PVC burden, activation mapping and successful ablation of different morphologies were achieved using a novel mapping tool, which facilitates simultaneous mapping of different PVC morphologies.

[Hypnosis rhythmology practice : Results of a French survey]

This survey evaluated hypnosis practice in French centres in June 2020. The survey was sent via email to different rhythmology centres in France and responses from cardiologists and nurses were obtained. We present here the preliminary results of this survey. Hypnosis was used on a regular basis in 7.5% of the centres and 13% of the participants received education on hypnosis. 75% of the participants were interested to have an education of hypnosis. The survey points the different possibilities of improvement of management of patients while having the different procedures.

Atrial fibrillation catheter ablation complications in obese and diabetic patients: Insights from the US Nationwide Inpatient Sample 2005-2013

BACKGROUND

Obesity and diabetes are risk factors for atrial fibrillation (AF) incidence and recurrence after catheter ablation. However, their impact on post-ablation complications in real-world practice is unknown.

OBJECTIVES

We examine annual trends in AF ablations and procedural outcomes in obese and diabetic patients in the US and whether obesity and diabetes are independently associated with adverse outcomes.

METHODS

Using the Nationwide Inpatient Sample (2005-2013), we identified obese and diabetic patients admitted for AF ablation. Common complications were identified using ICD-9-CM codes. The primary outcome included the composite of any in-hospital complication or death. Annual trends of the primary outcome, length-of-stay (LOS) and total-inflation adjusted hospital charges were examined. Multivariate analyses studied the association of obesity and diabetes with outcomes.

RESULTS

An estimated 106 462 AF ablations were performed in the US from 2005 to 2013. Annual trends revealed a gradual increase in ablations performed in obese and diabetic patients and in complication rates. The overall rate of the primary outcome in obese was 11.7% versus 8.2% in non-obese and 10.7% in diabetic versus 8.2% in non-diabetic patients (p < .001).

CONCLUSIONS

Obesity was independently associated with increased complications (adjusted OR, 95% CI:1.39, 1.20-1.62), longer LOS (1.36, 1.23-1.49), and higher charges (1.16, 1.12-1.19). Diabetes was only associated with longer LOS (1.27, 1.16-1.38). Obesity, but not diabetes, in patients undergoing AF ablation is an independent risk factor for immediate post-ablation complications and higher costs. Future studies should investigate whether weight loss prior to ablation reduces complications and costs.

The Electrophysiology Laboratory: Anesthetic Considerations and Staffing Models

The electrophysiology laboratory facilitates complex procedures on patients, many of whom have advanced disease processes and extensive comorbidities. Historically, nurses administered sedation as required, but in recent years a shift to anesthesiologist-led sedation has been promoted for patient safety and advanced therapeutic considerations. Uncertainty remains, however, regarding whether the electrophysiology laboratory is best staffed with general or cardiothoracic anesthesiologists. In this article, the authors discuss the anesthetic considerations of some commonly performed electrophysiology and structural cardiac procedures and the pros and cons of staffing with general or cardiothoracic anesthesiologists.

Safety of conscious sedation in electroanatomical mapping procedures and cryoballoon pulmonary vein isolation

Immobilization of patients during electrophysiological procedures, to avoid complications by patients' unexpected bodily motion, is achieved by moderate to deep conscious sedation using benzodiazepines and propofol for sedation and opioids for analgesia. Our aim was to compare respiratory and hemodynamic safety endpoints of cryoballoon pulmonary vein isolation (PVI) and electroanatomical mapping (EAM) procedures. Included patients underwent either cryoballoon PVI or EAM procedures. Sedation monitoring included non-invasive blood pressure measurements, transcutaneous oxygen saturation (tSpO₂) and transcutaneous carbon-dioxide (tpCO₂) measurements. We enrolled 125 consecutive patients, 67 patients underwent cryoballoon atrial fibrillation ablation and 58 patients had an EAM and radiofrequency ablation procedure. Mean procedure duration of EAM procedures was significantly longer (p < 0.001) and propofol doses as well as morphine equivalent doses of administered opioids were significantly higher in EAM patients compared to cryoballoon patients (p < 0.001). Cryoballoon patients display higher tpCO₂ levels compared to EAM patients at 30 min (cryoballoon: 51.1 ± 7.0 mmHg vs. EAM: 48.6 ± 6.2 mmHg, p = 0.009) and at 60 min (cryoballoon: 51.4 ± 7.3 mmHg vs. EAM: 48.9 ± 6.6 mmHg, p = 0.07) procedure duration. Mean arterial pressure was significantly higher after 60 min (cryoballoon: 84.7 ± 16.7 mmHg vs. EAM: 76.7 ± 13.3 mmHg, p = 0.017) in cryoballoon PVI compared to EAM procedures. Regarding respiratory and hemodynamic safety endpoints, no significant difference was detected regarding hypercapnia, hypoxia and episodes of hypotension. Despite longer procedure duration and deeper sedation requirement, conscious sedation in EAM procedures appears to be as safe as conscious sedation in cryoballoon ablation procedures regarding hemodynamic and respiratory safety endpoints.

Continuous transcutaneous carbon-dioxide monitoring to avoid hypercapnia in complex catheter ablations under conscious sedation

BACKGROUND

Ablation of complex cardiac arrhythmias requires an immobilized patient. For a successful and safe intervention and for patient comfort, this can be achieved by conscious sedation. Administered sedatives and analgesics have respiratory depressant side effects and require close monitoring. We investigated the feasibility and accuracy of additional, continuous transcutaneous carbon-dioxide partial pressure (tpCO₂) measurement during conscious sedation in complex electrophysiological catheter ablation procedures.

METHOD

We evaluated the accuracy and additional value of continuous tpCO₂ detection by application of a Severinghaus electrode in comparison to arterial and venous blood gas analyses.

RESULTS

We included 110 patients in this prospective observational study. Arterial pCO₂ (paCO₂) and tpCO₂ showed good correlation throughout the procedures (r = 0.60-0.87, p < 0.005). Venous pCO₂ (pvCO₂) were also well correlated to transcutaneous values (r = 0.65-0.85, p < 0.0001). Analyses of the difference of pvCO₂ and tpCO₂ measurements showed a tolerance within <10 mmHg in up to 96-98% of patients. Hypercapnia (pCO₂ < 70 mmHg) was detected more likely and earlier by continuous tpCO₂ monitoring compared to half-hourly pvCO₂ measurements.

CONCLUSION

Continuous tpCO₂ monitoring is feasible and precise with good correlation to arterial and venous blood gas carbon-dioxide analysis during complex catheter ablations under conscious sedation and may contribute to additional safety.

Nonoperating room anesthesia in different parts of the world

PURPOSE OF REVIEW

Advances in early diagnosis and treatment of diseases using minimally invasive procedures has led to an increase in the number of cases in locations outside the operating room. This surge created the need for anesthesia services to expand to these areas to provide well tolerated and favorable procedural conditions. The present review describes nonoperating room anesthesia patterns in different parts of the world.

RECENT FINDINGS

Nonoperating room anesthesia has grown exponentially over the last years. Patients scheduled in these areas are sicker and older compared to the operating room patients. Anesthesiologist-directed care has proven to be well tolerated, with less serious complications and improvement in patients and proceduralist satisfaction.

SUMMARY

There are marked variations in how anesthesia services are delivered in out of operating room locations in different parts of the world. Although there are some data available from the United States, expansion of minimally invasive procedures across continents will likely lead to the emergence of various models of delivering anesthetic care.

Congenital heart disease in adults (when kids grow up) pediatric geriatric anesthesia

PURPOSE OF REVIEW

The current review focuses on the new development of adult congenital heart disease (ACHD) patients in the areas of imaging, percutaneous interventions, ventricular assist devices and transplantation.

RECENT FINDINGS

Since the last ACHD publication in the journal, several advances have been made in the evaluation and treatment of these patients. As CHD patients' longevity increases pregnancy, comorbities and acquired heart disease become a concern. Recent data show that the incidence of complications in low-risk CHD is not higher that the regular population. In addition, breakthrough research in percutaneous valve implantation has been published showing good outcomes but needing intensive care recovery in a significant number of patients. In the ACHD heart failure population, assist device and transplant fields mounting evidence shows that these therapies should not be the last resort since low-risk ACHD patient may have similar outcomes to those with acquired heart disease. Finally risk stratification is important in ACHD to define better ways to recover from surgery and anesthesia.

SUMMARY

The field of anesthesia for ACHD is growing with new indications for diagnostic, interventional and surgical procedures. Tailoring cardiac and noncardiac care to the different risk profile in ACHD patients will be defined in the next few years.

VIDEO ABSTRACT

Motta summary clip: http://links.lww.com/COAN/A65.

Indications, contraindications, and safety aspects of procedural sedation

PURPOSE OF REVIEW

There is a steadily increasing demand for procedural sedation outside the operating room, frequently performed in comorbid high-risk adult patients. This review evaluates the feasibility and advantages of sedation vs. general anesthesia for some of these new procedures.

RECENT FINDINGS

Generally, sedation performed by experienced staff is safe. Although for some endoscopic or transcatheter interventions sedation is feasible, results of the intervention might be improved when performed under general anesthesia. For elected procedures like intra-arterial treatment after acute ischemic stroke, avoiding general anesthesia and sedation at all might be the optimal treatment.

SUMMARY

Anesthesiologists are facing continuously new indications for procedural sedation in sometimes sophisticated diagnostic or therapeutic procedures. Timely availability of anesthesia staff will mainly influence who is performing sedation, anesthesia or nonanesthesia personal. While the number of absolute contraindications for sedation decreased to almost zero, relative contraindications are becoming more relevant and should be tailored to the individual procedure and patient.

Dexmedetomidine Sedation for Paroxysmal Supraventricular Tachycardia Ablation Is Not Associated With Alteration of Arrhythmia Inducibility

BACKGROUND

Dexmedetomidine (Dex) is an attractive agent for procedural sedation due to its unique pharmacodynamic profile, specifically affording predictable sedation without concurrent respiratory depression. However, Dex has previously been reported to prevent or terminate arrhythmias. The purpose of this study was to investigate paroxysmal supraventricular tachycardia (PSVT) inducibility and homeostatic stability during electrophysiology studies (EPSs) and ablation when a standardized Dex protocol was used as the primary sedation agent.

METHODS

We performed a retrospective review of 163 consecutive procedures for PSVT ablation that received Dex as the primary sedative with adjunct fentanyl and midazolam boluses (DEX-FENT-MIDAZ). This cohort was compared to 163 consecutive control procedures wherein strictly fentanyl and midazolam were used for sedation. The primary outcome reviewed was PSVT inducibility assessed before ablation. Reviewed secondary outcomes included level of sedation and intraprocedure hemodynamics and oxygenation.

RESULTS

The arrhythmia profiles of the DEX-FENT-MIDAZ and control cohorts were very similar. The overall incidence of a "negative" EPSs in which arrhythmia was not induced was 24% in the DEX-FENT-MIDAZ group and 26% in the control group (P = .7). Unintended deep sedation was significantly less with DEX-FENT-MIDAZ (4.3% vs 27%; P ≤ .0001). However, DEX-FENT-MIDAZ use was associated with a higher incidence of intraprocedure hypotension.

CONCLUSIONS

Dex sedation during EPSs is not associated with a reduction in PSVT inducibility. The therapeutic utility of Dex during EPS arises from the predictable sedation Dex affords but is associated with an increased incidence of intraprocedure hypotension.

Coronary vasospasm caused by intravenous infusion of dexmedetomidine: Unrecognized pitfall of catheter ablation procedures of atrial fibrillation

Coronary vasospasm is an emerging potentially lethal complication of catheter ablation for atrial fibrillation (AF), however, its mechanism in this setting has not been well elucidated. A 55-year-old man with symptomatic paroxysmal AF underwent pulmonary vein isolation under sedation with propofol. The procedure was completed without any complications. Fifteen months later, a repeated session was performed because of AF recurrence. Initially, a high-dose infusion of dexmedetomidine instead of propofol was administered to introduce sedation. Then, an ST-segment elevation developed in the inferior leads and the diagnosis of coronary vasospasm was made by urgent coronary angiography. A comparison of the procedural details between the first and second sessions identified dexmedetomidine, an α-2 adrenergic agonist with a short distribution half-life, as a potential cause of coronary vasospasm seen only in the second session in the same individual. Since it has been shown that α-2 adrenoreceptor-mediated vasoconstriction can involve the coronary circulation, it is thus possible that a stimulation of α-2 adrenergic receptors induced by dexmedetomidine caused a coronary vasospasm. The present case provides new insights into dexmedetomidine-induced vasospasm. Physicians should be aware of this potentially lethal side effect of dexmedetomidine which is increasingly used in the current AF ablation practice. <Learning Objective: Dexmedetomidine has become widely used during catheter ablation for atrial fibrillation since it is generally regarded as a safe drug for sedation and analgesia with fewer respiratory depressant effects compared to other agents. However, it should be noted that dexmedetomidine may cause a coronary vasospasm, especially at the time of an initial high loading-dose infusion. Physicians should be aware of this potentially lethal side effect of dexmedetomidine.>.

Effects of anesthetic and sedative agents on sympathetic nerve activity

BACKGROUND

The effects of sedative and anesthetic agents on sympathetic nerve activity (SNA) are poorly understood.

OBJECTIVE

The purpose of this study was to determine the effects of commonly used sedative and anesthetic agents on SNA in ambulatory dogs and humans.

METHODS

We implanted radiotransmitters in 6 dogs to record stellate ganglion nerve activity (SGNA), subcutaneous nerve activity (ScNA), and blood pressure (BP). After recovery, we injected dexmedetomidine (3 μg/kg), morphine (0.1 mg/kg), hydromorphone (0.05 mg/kg), and midazolam (0.1 mg/kg) on different days. We also studied 12 human patients (10 male; age 68.0 ± 9.1 years old) undergoing cardioversion for atrial fibrillation with propofol (0.77 ± 0.18 mg/kg) or methohexital (0.65 mg/kg) anesthesia. Skin sympathetic nerve activity (SKNA) and electrocardiogram were recorded during the study.

RESULTS

SGNA and ScNA were significantly suppressed immediately after administration of dexmedetomidine (P = .000 and P = .000, respectively), morphine (P = .011 and P = .014, respectively), and hydromorphone (P = .000 and P = .012, respectively), along with decreased BP and heart rate (HR) (P <.001 for each). Midazolam had no significant effect on SGNA and ScNA (P = .248 and P = .149, respectively) but increased HR (P = .015) and decreased BP (P = .004) in ambulatory dogs. In patients undergoing cardioversion, bolus propofol administration significantly suppressed SKNA (from 1.11 ± 0.25 μV to 0.77 ± 0.15 μV; P = .001), and the effects lasted for at least 10 minutes after the final cardioversion shock. Methohexital decreased chest SKNA from 1.59 ± 0.45 μV to 1.22 ± 0.58 μV (P = .000) and arm SKNA from 0.76 ± 0.43 μV to 0.55 ± 0.07 μV (P = .001). The effects lasted for at least 10 minutes after the cardioversion shock.

CONCLUSION

Propofol, methohexital, dexmedetomidine, morphine, and hydromorphone suppressed, but midazolam had no significant effects on, SNA.

Deep sedation for transvenous lead extraction: a large single-centre experience

Aims

Transvenous lead extraction for cardiac implantable electronic devices (CIED) is of growing importance. Nevertheless, the optimal anaesthetic approach, general anaesthesia vs. deep sedation (DS), remains unresolved. We describe our tertiary centre experience of the feasibility and safety of DS.

Methods and results

Extraction procedures were performed in the electrophysiology (EP) laboratory by two experienced electrophysiologists. We used intravenous Fentanyl, Midazolam, and Propofol for DS. A stepwise approach with locking stylets, dilator sheaths, and mechanical sheaths via subclavian, femoral, or internal jugular venous access was utilized. Patient characteristics and procedural data were collected. Logistic regression models were used to identify parameters associated with sedation-related complications. Extraction of 476 leads (dwelling time/patient 88 ± 49 months, 30% ICD leads) was performed in 220 patients (64 ± 17 years, 80% male). Deep sedation was initiated with bolus administration of Fentanyl, Midazolam, and Propofol; mean doses 0.34 ± 0.12 μg/kg, 24.3 ± 6.8 μg/kg, and 0.26 ± 0.13 mg/kg, respectively. Deep sedation was maintained with continuous Propofol infusion (initial dose 3.7 ± 1.1 mg/kg/h; subsequently increased to 4.7 ± 1.2 mg/kg/h with 3.9 ± 2.6 adjustments) and boluses of Midazolam and Fentanyl as indicated. Sedation-related episodes of hypotension, requiring vasopressors, and hypoxia, requiring additional airway management, occurred in 25 (11.4%) and 5 (2.3%) patients, respectively. These were managed without adverse consequences. Five patients (2.3%) experienced major intraprocedural complications; there were no procedure-related deaths. All of our logistic regression models indicated intraprocedural support was associated with administration higher Fentanyl doses.

Conclusion

Transvenous lead extraction under DS in the EP laboratory is a safe procedure with high success rates when performed by experienced staff.

Anaesthetic management of a patient with Fontan physiology for electrophysiology study and catheter ablation

The success of the Fontan procedure for congenital single ventricle anatomy has resulted in adult patients with Fontan physiology requiring anaesthesia for cardiac and non-cardiac procedures. We present the perioperative management of a patient with Fontan physiology who underwent electrophysiological study with radiofrequency ablation for atrial tachycardia under general anaesthesia. Good communication between the multidisciplinary teams, a detailed understanding of the patient's complex cardiac anatomy and physiology, as well as the ability to recognise and manage perioperative complications all play a vital role for a successful outcome.

Sedation in cardiac arrhythmias management

INTRODUCTION

Procedural sedation is of paramount importance for a plethora of electrophysiological procedures. From electrical cardioversion to electrophysiology studies, device implantations, and catheter ablations, intraprocedural sedation and anesthesia have a pivotal role in allowing procedural success while ensuring patient safety and avoiding discomfort. Areas covered: The present review will discuss the current state-of-the-art in sedation and anesthesia during electrical cardioversion, cardiac implantable electronic device implantation, catheter ablation and electrophysiology studies. Specific information will be provided for each procedure in order to reach the core of this important clinical issue, and specific protocols will be compared. The main pro-arrhythmic and anti-arrhythmic effects of the most commonly used sedatives will also be discussed. Expert commentary: According to much recent evidence, the cardiologist can be the only person responsible for sedation administration in many settings, highlighting few safety issues associated with the absence of a dedicated anesthesiologist thus a concomitant reduction in costs. However, many concerns have been raised in allowing non-anesthesiologists to manage sedatives, as adverse events, while rare, could have catastrophic consequences. The present paper will highlight when a cardiologist-directed sedation is considered safe, how it should be performed, and the pros and cons related to this strategy.

Use of Dexmedetomidine in Cardiothoracic and Vascular Anesthesia

Dexmedetomidine is a highly selective α₂-adrenergic agonist with analgesic and sedative properties. In the United States, the Food and Drug Administration approved the use of the drug for short-lasting sedation (24 h) in intensive care units (ICUs) in patients undergoing mechanical ventilation and endotracheal intubation. In October 2008, the Food and Drug Administration extended use of the drug for the sedation of nonintubated patients before and during surgical and nonsurgical procedures. In the European Union, the European Medicine Agency approved the use of dexmedetomidine in September 2011 with a single recognized indication: ICU adult patients requiring mild sedation and awakening in response to verbal stimulus. At present, the use of dexmedetomidine for sedation outside the ICU remains an off-label indication. The benefits of dexmedetomidine in critically ill patients and in cardiac, electrophysiology-related, vascular, and thoracic procedures are discussed.

Anesthesia in the Electrophysiology Laboratory

The electrophysiology suite is a foreign location to many anesthesiologists. The initial experience was with shorter procedures under conscious sedation, and the value of greater tailoring of the sedation/anesthesia by anesthesiologists was not perceived until practice patterns had already been established. Although better control of ventilation with general anesthesia may be expected, suppression of arrhythmias, blunting of the hemodynamic adaptation to induced arrhythmias, and interference by muscle relaxants with identification of the phrenic nerve may be seen. We review a range of electrophysiology procedures and discuss anesthetic approaches that balance patient safety and favorable outcomes.