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.

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.

Effect of a dexmedetomidine substitution during a nationwide propofol shortage in patients undergoing coronary artery bypass graft surgery.

STUDY OBJECTIVE: To assess the effect of substituting dexmedetomidine for propofol during a nationwide propofol shortage on postoperative time to extubation and opioid requirements in patients who underwent coronary artery bypass graft (CABG) surgery. DESIGN: Retrospective case-control study. SETTING: Single-center cardiothoracic intensive care unit (ICU) in a tertiary academic medical center. PATIENTS: Seventy adults undergoing isolated, primary, elective CABG who received dexmedetomidine between April 1 and June 30, 2010, during the propofol shortage (35 patients [cases]) or who received propofol between January 1 and March 31, 2010, or between July 1 and September 30, 2010 (35 patients [controls]) for postoperative sedation were included. Patients in the dexmedetomidine group were matched 1:1 to patients in the propofol group based on age, sex, weight, number of vessels bypassed, preoperative ejection fraction, cardiopulmonary bypass time, and aortic cross-clamp time. MEASUREMENTS AND MAIN RESULTS: The primary outcome consisted of opioid requirements in the first 12 hours after arrival to the ICU in the dexmedetomidine- and propofol-treated patients. Secondary outcomes included the time to extubation (from ICU admission until extubation) and opioid requirements in the first 24 hours. No significant demographic differences were noted between treatment groups. Median opioid requirements in the first 12 hours, as measured by morphine equivalents, were 8.0 mg in the propofol group and 7.0 mg in the dexmedetomidine group (p=0.1). Similarly, at 24 hours, opioid requirements were 16.7 and 17.3 mg in the propofol and dexmedetomidine groups, respectively (p=0.4). The time to extubation demonstrated that patients in the propofol group were extubated at a median of 300 minutes and patients in the dexmedetomidine group were extubated at a median of 318 minutes after ICU arrival (p=0.5). CONCLUSION: No statistically significant differences were noted between the propofol and dexmedetomidine groups when assessing the outcomes of opioid requirements and the time to extubation. A multicenter, prospective, randomized, blinded study is needed to determine the optimal sedative after CABG surgery.

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.