Utilization of an Endobronchial Blocker Through a Double-Lumen Tube as Rescue for Inadequate One-Lung Ventilation.

Failure to provide one-lung ventilation can prohibit minimally invasive thoracic surgeries. Strategies for one-lung ventilation include double-lumen endotracheal tubes or endobronchial blockers, but rarely both. Inability to provide lung isolation after double-lumen endotracheal tube placement requires troubleshooting and sometimes the use of extra equipment. This case describes using a unique Y-shaped endobronchial blocker placed through a left-sided double-lumen endotracheal tube after failure to achieve lung isolation with a double-lumen endotracheal tube alone.

Advances in awareness monitoring technologies.

PURPOSE OF REVIEW: Initial studies suggested that the use of processed electroencephalogram technology could significantly decrease the incidence of unintended intraoperative awareness events during general anesthesia. Subsequent work has cast doubts on these findings. This review will examine the current state of awareness monitoring. RECENT FINDINGS: Recently published randomized controlled trials examining the use of the bispectral index during general anesthesia have not been able to show superiority over other forms of monitoring depth of anesthesia, such as end-tidal anesthetic-agent concentration. Additionally, there is current interest in utilizing the unprocessed electroencephalogram to ascertain depth of anesthesia and recent studies have demonstrated its use in preventing postoperative delirium. SUMMARY: Although awareness monitors such as the bispectral index monitor may have benefit in patients in whom volatile anesthetic agents must be minimized - such as in hemodynamically unstable patients, or patients undergoing total intravenous anesthesia - these monitors do not appear to be useful for all patients.

Monitored Anesthesia Care for Subcutaneous Cardioverter-Defibrillator Implantation: A Single-Center Experience.

BACKGROUND: To date, general anesthesia has been suggested as the preferred approach for implantation of a subcutaneous implantable cardioverter-defibrillator (S-ICD). The purpose of this study was to assess the use of monitored anesthesia care (MAC) for S-ICD implantation. The goals were to assess adequate sedation and analgesia (efficacy endpoints) and major perioperative airway or hemodynamic compromise (safety endpoints). The authors hypothesized that MAC may provide adequate sedation and analgesia and no major perioperative airway or hemodynamic compromise during S-ICD implantation and multiple defibrillation threshold (DFT) testing. METHODS: Prospectively collected data of patients who underwent S-ICD implantation with MAC from 2015 to 2016 were analyzed retrospectively. The efficacy endpoints were the provision of an optimal depth of sedation and analgesia to facilitate S-ICD implantation without intra-procedure patient discomfort or awareness, and the absence of "severe" pain at the lead tunneling and the generator insertion sites post-procedure. The safety endpoints included: (1) periprocedural hypotension, as defined by a mean arterial pressure (MAP)<60 mmHg refractory to conventional pharmacotherapy, (2) heart rate (HR)<45 bpm requiring pharmacologic support, and (3) sedation-induced airway compromise requiring endotracheal intubation. MEASUREMENTS: MAP and HR were recorded during S-ICD implantation and DFT testing. The maximum and minimum infusion rates of propofol, supplemental sedatives, and analgesics, and doses of vasopressor and/or inotropic agents administered intra-procedurally were recorded. Post-procedure pain scores also were noted. RESULTS: Ten patients underwent S-ICD implantation with MAC (mean age, 56 years; 50% men; mean left ventricular ejection fraction was 39%). Implantation of the S-ICD system using MAC was successful in all patients without any major adverse events. The mean baseline MAP was 92.8 mmHg, and the mean end-procedure MAP was 88 mmHg (p = 0.26). When compared to baseline and end-procedure, the mean lowest intra-procedure MAP was significantly lower (67.4 mmHg; p = 0.0001). The mean baseline HR was 65.7 bpm, and the mean end-procedure HR was 70.1 bpm (p = 0.28). When compared to baseline and end-procedure, the mean lowest intra-procedure HR was significantly lower (55.8 bpm; p<0.001). MAC was not associated with airway compromise in any patient, and post-procedure pain was rated as no greater than "mild". CONCLUSIONS: Among a heterogeneous patient population undergoing S-ICD implantation and DFT testing, the use of MAC is efficacious, feasible, and safe.

Anesthesia care for subcutaneous implantable cardioverter/defibrillator placement: a single-center experience.

BACKGROUND: The recently approved subcutaneous implantable cardioverter/defibrillator (S-ICD) uses a single extrathoracic subcutaneous lead to treat life-threatening ventricular arrhythmias, such as ventricular tachycardia and ventricular fibrillation. This is different from conventional transvenous ICDs, which are typically implanted under sedation. Currently, there are no reports regarding the anesthetic management of patients undergoing S-ICD implantation. STUDY OBJECTIVES: This study describes the anesthetic management and outcomes in patients undergoing S-ICD implantation and defibrillation threshold (DFT) testing. METHODS: The study population consists of 73 patients who underwent S-ICD implantation. General anesthesia (n = 69, 95%) or conscious/deep sedation (n = 4, 5%) was used for device implantation. MEASUREMENTS: Systolic blood pressure (SBP) and heart rate were recorded periprocedurally for S-ICD implantation and DFTs. Major adverse events were SBP <90 mm Hg refractory to vasopressor agents, significant bradycardia (heart rate <45 beats per minute) requiring pharmacologic intervention and, "severe" pain at the lead tunneling site and the S-ICD generator insertion site based on patient perception. INTERVENTIONS: Of the 73 patients, 39 had SBP <90 mm Hg (53%), and intermittent boluses of vasopressors and inotropes were administered with recovery of SBP. In 2 patients, SBP did not respond, and the patients required vasopressor infusion in the intensive care unit. MAIN RESULTS: Although the S-ICD procedure involved extensive tunneling and a mean of 2.5 ± 1.7 DFTs per patient, refractory hypotension was a major adverse event in only 2 patients. The mean baseline SBP was 132.5 ± 22.0 mm Hg, and the mean minimum SBP during the procedure was 97.3 ± 9.2 mm Hg (P < .01). There was also a mean 13-beats per minute decrease in heart rate (P < .01), but no pharmacologic intervention was required. Eight patients developed "severe" pain at the lead tunneling and generator insertion sites and were adequately managed with intravenous morphine. CONCLUSIONS: Among a heterogeneous population, anesthesiologists can safely manage patients undergoing S-ICD implantation and repeated DFTs without wide swings in SBP and with minimal intermittent pharmacologic support.

Elective Thoracoscopic Maze with Venoarterial Extracorporeal Life Support.

This case report describes the intraoperative use of extracorporeal life support (ECLS) for an elective thoracoscopic maze procedure in which the patient could not tolerate one-lung ventilation because of hypoxia. Potential pitfalls associated with the anesthetic management of elective intraoperative ECLS include managing native cardiac ejection and ECLS flows to provide optimal oxygenation and cardiac output. Particular attention must be paid to cardiac and respiratory physiology when ECLS is used in a patient with normal cardiac function.

Diagnosis and Rescue of a Kinked Pulmonary Artery Catheter.

Invasive hemodynamic monitoring with a pulmonary catheter has been relatively routine in cardiovascular and complex surgical operations as well as in the management of critical illnesses. However, due to multiple potential complications and its invasive nature, its use has decreased over the years and less invasive methods such as transesophageal echocardiography and hemodynamic sensors have gained widespread favor. Unlike these less invasive forms of hemodynamic monitoring, pulmonary artery catheters require an advanced understanding of cardiopulmonary physiology, anatomy, and the potential for complications in order to properly place, manage, and interpret the device. We describe a case wherein significant resistance was encountered during multiple unsuccessful attempts at removing a patient's catheter secondary to kinking and twisting of the catheter tip. These attempts to remove the catheter serve to demonstrate potential rescue options for such a situation. Ultimately, successful removal of the catheter was accomplished by simultaneous catheter retraction and sheath advancement while gently pulling both objects from the cannulation site. In addition to being skilled in catheter placement, it is imperative that providers comprehend the risks and complications of this invasive monitoring tool.

Relationship between anesthetic depth and venous oxygen saturation during cardiopulmonary bypass.

BACKGROUND: During cardiopulmonary bypass, mixed venous oxygen saturation (Svo2) is frequently measured to assess circulatory adequacy. Fluctuations in Svo2 not related to patient movement or inadequate oxygen delivery have been attributed clinically to increased cerebral oxygen consumption due to "light" anesthesia. To evaluate the relationship between anesthetic depth and Svo2, we prospectively measured bispectral index (BIS) and Svo2 values in patients undergoing cardiac surgery with cardiopulmonary bypass. METHODS: Adults scheduled for cardiac surgery with cardiopulmonary bypass were recruited for this prospective observational study. During bypass, BIS and Svo2 values were recorded every 5 min. To control for confounding effects of changes in other variables known to affect Svo2, temperature, hematocrit, bypass pump flow, muscle relaxant use, and intravenous and inhaled anesthetic doses were also recorded. Only periods with limited variation in other variables affecting Svo2 were analyzed. The relationship between BIS and Svo2 was evaluated using mixed linear regression. RESULTS: One thousand thirty-four data points were obtained in 41 patients. No overall association between BIS and Svo2 was observed, either in unadjusted analysis or adjusted for covariates. In data points with temperatures less than the median (T < 34.1 degrees C), a significant association between BIS and Svo2 was observed both in unadjusted (beta = -0.32, P = 0.01) and adjusted (beta = -0.27, P = 0.04) analyses. CONCLUSIONS: In patients undergoing cardiopulmonary bypass, we found no overall association between BIS and Svo2. A weak but statistically significant association between BIS and Svo2 was observed in patients with temperatures less than 34.1 degrees C. These data suggest that low Svo2 values on bypass are unlikely to be due to light or inadequate anesthesia. The relationship among temperature, BIS and Svo2 deserves further study.

Chronic expression of monocyte chemoattractant protein-1 in the central nervous system causes delayed encephalopathy and impaired microglial function in mice.

Increased central nervous system (CNS) levels of monocyte chemoattractant protein 1 [CC chemokine ligand 2 (CCL2) in the systematic nomenclature] have been reported in chronic neurological diseases such as human immunodeficiency virus type 1-associated dementia, amyotrophic lateral sclerosis, and multiple sclerosis. However, a pathogenic role for CCL2 has not been confirmed, and there is no established model for the effects of chronic CCL2 expression on resident and recruited CNS cells. We report that aged (>6 months) transgenic (tg) mice expressing CCL2 under the control of the human glial fibrillary acidic protein promoter (huGFAP-CCL2hi tg+ mice) manifested encephalopathy with mild perivascular leukocyte infiltration, impaired blood brain barrier function, and increased CD45-immunoreactive microglia, which had morphologic features of activation. huGFAP-CCL2hi tg+ mice lacking CC chemokine receptor 2 (CCR2) were normal, showing that chemokine action via CCR2 was required. Studies of cortical slice preparations using video confocal microscopy showed that microglia in the CNS of huGFAP-CCL2hi tg+ mice were defective in expressing amoeboid morphology. Treatment with mutant CCL2 peptides, a receptor antagonist and an obligate monomer, also suppressed morphological transformation in this assay, indicating a critical role for CCL2 in microglial activation and suggesting that chronic CCL2 exposure desensitized CCR2 on microglia, which in the CNS of huGFAP-CCL2hi tg+ mice, did not up-regulate cell-surface expression of major histocompatibility complex class II, CD11b, CD11c, or CD40, in contrast to recruited perivascular macrophages that expressed enhanced levels of these markers. These results indicate that huGFAP-CCL2hi tg+ mice provide a useful model to study how chronic CNS expression of CCL2 alters microglial function and CNS physiology.