Inappropriate Implantable Cardioverter-Defibrillator Therapy With the Use of an Underbody Electrosurgery Dispersive Electrode.

Perioperative management of implantable cardioverter-defibrillators is an important part of anesthetic care. Society recommendations and expert consensus statements exist to aid clinicians, and they have identified the umbilicus as an important landmark in decision-making. Implantable cardioverter-defibrillator antitachycardia therapy may not need to be deactivated for infraumbilical surgery because electromagnetic interference is unlikely to occur. The authors present two cases in which inappropriate antitachycardia therapy occurred intraoperatively with use of an underbody dispersive electrode, even though both surgeries were infraumbilical. The authors also present two cadaver models to demonstrate how monopolar electrosurgery below the umbilicus is sensed using both traditional and underbody dispersive electrosurgical return electrodes.

A Prospective Comparison of Intraluminal and Extraluminal Placement of the 9-French Arndt Bronchial Blocker in Adult Thoracic Surgery Patients.

OBJECTIVE: To compare the standard intraluminal approach with the placement of the 9-French Arndt endobronchial blocker with an extraluminal approach by measuring the time to positioning and other relevant intraoperative and postoperative parameters. DESIGN: A prospective, randomized, controlled trial. SETTING: University hospital. PARTICIPANTS: The study comprised 41 patients (20 intraluminal, 21 extraluminal) undergoing thoracic surgery. INTERVENTION: Placement of a 9-French Arndt bronchial blocker either intraluminally or extraluminally. Comparisons between the 2 groups included the following: (1) time for initial placement, (2) quality of isolation at 1-hour intervals during one-lung ventilation, (3) number of repositionings during one-lung ventilation, and (4) presence or absence of a sore throat on postoperative days 1 and 2 and, if present, its severity. MEASUREMENTS AND MAIN RESULTS: Median time to placement (min:sec) in the extraluminal group was statistically faster at 2:42 compared with 6:24 in the intraluminal group (p < 0.05). Overall quality of isolation was similar between groups, even though a significant number of blockers in both groups required repositioning (extraluminal 47%, intraluminal 40%, p > 0.05), and 1 blocker ultimately had to be replaced intraoperatively. No differences in the incidence or severity of sore throat postoperatively were observed. CONCLUSIONS: A statistically significant reduction in time to placement using the extraluminal approach without any differences in the rate of postoperative sore throat was observed. Whether placed intraluminally or extraluminally, a significant percentage of Arndt endobronchial blockers required at least one intraoperative repositioning.

Acute cardiac tamponade during atrial flutter ablation: improved hemodynamics after positive pressure ventilation: a case report.

INTRODUCTION: Acute cardiac tamponade is a rare event during any type of interventional or surgical procedure. It can occur during electrophysiology procedures due to radiofrequency ablation, lead or catheter manipulation, transseptal puncture, laser lead extractions, or left atrial appendage occlusion device positioning. Cardiac tamponade is difficult to study in a prospective manner, and case reports and case series are important contributions to understanding the best options for patient care. An 87-year-old Caucasian male patient breathing spontaneously developed acute tamponade during an atrial flutter ablation. Pericardial drain insertion was difficult, and hypotension failed to respond to epinephrine boluses. The patient became hypoxemic and hypercarbic, requiring intubation. Unexpectedly, the blood pressure markedly increased postintubation and remained in a normal range until the pericardium was drained. CONCLUSION: Spontaneous ventilation is considered important to maintain venous return to the right heart during cardiac tamponade. However, spontaneous ventilation reduces venous return to the left heart and worsens the paradoxical pulse in tamponade. Intravenous vasopressors are thought to be ineffective during cardiac tamponade. Our patient maintained pulmonary blood flow as indicated by end-tidal carbon dioxide measurements but had no measurable systemic blood pressure during spontaneous ventilation. Our case demonstrates that tracheal intubation and positive pressure ventilation can transiently improve left heart venous return, systemic perfusion, and drug delivery to the systemic circulation.

Comparison of Bolus Dosing of Methohexital and Propofol in Elective Direct Current Cardioversion.

Background Methohexital and propofol can both be used as sedation for direct current cardioversion (DCCV). However, there are limited data comparing these medications in this setting. We hypothesized that patients receiving methohexital for elective DCCV would be sedated more quickly, recover from sedation faster, and experience less adverse effects. Methods and Results This was a prospective, blinded randomized controlled trial conducted at a single academic medical center. Eligible participants were randomly assigned to receive either methohexital (0.5 mg/kg) or propofol (0.8 mg/kg) as a bolus for elective DCCV. The times from bolus of the medication to achieving a Ramsay Sedation Scale score of 5 to 6, first shock, eyes opening on command, and when the patient could state their age and name were obtained. The need for additional medication dosing, airway intervention, vital signs, and medication side effects were also recorded. Seventy patients who were randomized to receive methohexital (n=37) or propofol (n=33) were included for analysis. The average doses of methohexital and propofol were 0.51 mg/kg and 0.84 mg/kg, respectively. There were no significant differences between methohexital and propofol in the time from end of injection to loss of conscious (1.4±1.8 versus 1.1±0.5 minutes; P=0.33) or the time to first shock (1.7±1.9 versus 1.4±0.5 minutes; P=0.31). Time intervals were significantly lower for methohexital compared with propofol in the time to eyes opening on command (5.1±2.5 versus 7.8±3.7 minutes; P=0.0005) as well as at the time to the ability to answer simple questions of age and name (6.0±2.6 versus 8.6±4.0 minutes; P=0.001). The methohexital group experienced less hypotension (8.1% versus 42.4%; P<0.001) and less hypoxemia (0.0% versus 15.2%; P=0.005), had lower need for jaw thrust/chin lift (16.2% versus 42.4%; P=0.015), and had less pain on injection compared with propofol using the visual analog scale (7.2±9.7 versus 22.4±28.1; P=0.003). Conclusions In this model of fixed bolus dosing, methohexital was associated with faster recovery, more stable hemodynamics, and less hypoxemia after elective DCCV compared with propofol. It can be considered as a preferred agent for sedation for DCCV. Registration URL: https://www.clinicaltrials.gov/ct; Unique identifier: NCT04187196.

Airway collapse with an anterior mediastinal mass despite spontaneous ventilation in an adult.

Patients with anterior mediastinal masses are at increased risk for perioperative complications. Our case demonstrates that airway collapse and inability to ventilate may occur in the asymptomatic adult despite spontaneous ventilation with inhaled anesthesia and an endotracheal tube. Given the sudden and profound presentation of cardiopulmonary collapse, rigid bronchoscopy should be immediately available to facilitate life-saving ventilation. Though repositioning the pediatric patient lateral or prone has been reported to reestablish airway patency, this maneuver may be of limited benefit in the adult population because of a more ossified and developed chest wall. Lastly, if a high-risk patient requires a general anesthetic, strong consideration should be given to preinduction placement of femoral cardiopulmonary bypass cannulae and the availability to immediately initiate cardiopulmonary bypass.

Coronary artery stents: Part I. Evolution of percutaneous coronary intervention.

The subspecialty of interventional cardiology has made significant progress in the management of coronary artery disease over the past three decades with the development of percutaneous coronary transluminal angioplasty, atherectomy, and bare-metal and drug-eluting stents (DES). Bare-metal stents (BMS) maintain vessel lumen diameter by acting as a scaffold and prevent collapse incurred by angioplasty. However, these devices cause neointimal hyperplasia leading to in-stent restenosis and requiring reintervention in more than 20% of patients by 6 mo. DES (sirolimus and paclitaxel) prevent restenosis by inhibiting neointimal hyperplasia. However, DESs also delay endothelialization, causing the stents to remain thrombogenic for an extended, yet unknown, period of time. Late stent thrombosis is associated with a 45% mortality rate. Premature discontinuation of antiplatelet therapy, particularly clopidogrel, is the strongest predictor of stent thrombosis. Sixty percent of patients receive stents for off-label (unapproved) indications, which also increases the frequency of stent thrombosis. Clopidogrel and aspirin are the cornerstone of therapy in the prevention of stent thrombosis in both BMS and DES. Recommendations pertaining to the optimal duration of dual-antiplatelet therapy have been debated. Both the Food and Drug Administration and the American Heart Association/American College of Cardiologists, in association with other major societies, have made recommendations to extend the duration of dual-antiplatelet therapy in patients with DES to 1 yr. The 6-wk duration of dual-antiplatelet therapy in patients with BMS remains unchanged. All patients with coronary stents must remain on life-long aspirin monotherapy. Since the introduction of percutaneous transluminal coronary angioplasty for the treatment of coronary atherosclerosis, the practice of percutaneous coronary intervention has undergone a dramatic transformation from simple balloon dilation catheters to sophisticated mechanical endoprostheses. These advancements have impacted the practice of perioperative medicine. In this series of two articles, in Part I we will review the evolution of percutaneous coronary intervention and discuss the issues associated with percutaneous transluminal coronary angioplasty and coronary stenting; in Part II we will discuss perioperative issues and management strategies of coronary stents during noncardiac surgery.

Coronary artery stents: II. Perioperative considerations and management.

The management of patients with coronary artery stents during the perioperative period is one of the most important patient safety issues clinicians confront. Perioperative stent thrombosis is a life-threatening complication for patients with either bare-metal or drug-eluting stents. Noncardiac surgery appears to increase the risk of stent thrombosis, myocardial infarction, and death, particularly when patients undergo surgery early after stent implantation. The incidence of complications is further increased when dual-antiplatelet therapy is discontinued preoperatively. It is generally agreed that aspirin must be continued throughout the perioperative period, except in circumstances when the risk of bleeding significantly outweighs the benefit of continued anticoagulation, such as procedures performed in a closed space. We present considerations for regional anesthesia, as well as postoperative recommendations as the occurrence of perioperative stent thrombosis appears to be greatest during this period. Immediate percutaneous coronary intervention is the definitive treatment for perioperative stent thrombosis, and 24-h access to an interventional cardiology suite should be readily available. Algorithms for perioperative management of patients with bare-metal and drug-eluting stents are proposed.