Remede Systems: Transvenous Pacing of the Phrenic Nerve.

The remede System (ZOLL Medical, Minnetonka, MN; Fig 1), which was approved by the Food and Drug Administration in October of 2017, is a transvenous device that stimulates the phrenic nerve for the treatment of central sleep apnea, which is often associated with heart failure and atrial fibrillation. Given the similarity in implantation procedure to pacemakers and implantable cardioverter/defibrillators, the remede System implantation often occurs in the electrophysiology laboratory. Despite the transvenous nature and close proximity to cardiac structures on radiographic imaging, the remede System does not have any cardiac pacing function/antiarrhythmia therapies, and it is important for an anesthesiologist to be able to recognize and manage such a device if they were to come across one preoperatively.

Refractory Hypotension During Implantation of a 70 mL Total Artificial Heart in a Patient With Pectus Excavatum: A Case Report.

The Syncardia total artificial heart system is the only commercially approved durable device for treating biventricular heart failure patients awaiting heart transplantation. Conventionally, the Syncardia total artificial heart system is implanted based on the distance from the anterior aspect of the 10th thoracic vertebra to the sternum and the patient's body surface area. However, this criterion does not account for chest wall musculoskeletal deformities. This case report describes a patient with a pectus excavatum who developed compression of the inferior vena cava after Syncardia total artificial heart implantation and how transesophageal echocardiography guided chest wall surgery to accommodate the total artificial heart system.

Cefazolin-Induced Thrombocytopenia in a Patient with Polycythemia Vera Following Coronary Artery Bypass.

Cefazolin is an antibiotic that is commonly administered perioperatively to reduce the risk of surgical site infections. Cephalosporins have a well-established safety profile, but have been associated with thrombocytopenia and neutropenia due to their myelosuppressive effects. While this effect may be benign in healthy patients undergoing minor surgery, it can be detrimental in patients with underlying hematologic disorders presenting for open-heart surgery. Herein, we discuss the first case in the literature of cefazolin-induced thrombocytopenia and severe coagulopathy in a patient with polycythemia vera (PCV) during a coronary artery bypass-grafting surgery.

Feasibility and safety of same day subcutaneous defibrillator implantation and send home (DASH) strategy.

PURPOSE: To assess the feasibility and safety of same-day discharge after S-ICD implantation by implementing a specific analgesia protocol and phone follow-up. METHODS: Consecutive patients presenting for outpatient S-ICD implantation were enrolled between 1/1/2018 and 4/30/2019. An analgesia protocol included pre-operative acetaminophen and oxycodone, intraoperative local bupivacaine, and limited use of oxycodone-acetaminophen at discharge. The primary outcome was successful same-day discharge. Numerical Pain Rating Scale (NPRS) on postoperative day (POD) 1, 3, 14, and 30 and any unplanned health care visits during the 1-month follow-up period were assessed. RESULTS: Out of 53 potentially eligible S-ICD patients, 49 patients (92.5%) were enrolled and successfully discharged on the same day. Mean age of these 49 patients was 47 ± 14 years. There were no acute procedural complications. Severe pain (NPRS ≥ 8) on POD 0, 1, and 3 was present in 14.3%, 14.3%, and 8.2% of patients, respectively. The total in-hospital stay was 534 ± 80 min. Four unplanned visits (8%) due to cardiac or device-related issues occurred during 1-month follow-up, including 2 patients with heart failure exacerbation, one patient with an incisional infection, and one patient with inappropriate shocks. CONCLUSIONS: With the appropriate institutional protocol including specific analgesics and phone follow-up, same-day discharge after outpatient S-ICD implantation is feasible and appears safe for most patients.. Device-related pain can be severe in the first 3 days post-implantation and can be successfully treated with limited supply of narcotic medications.

Implantation of subcutaneous defibrillator is feasible and safe with monitored anesthesia care.

BACKGROUND: The perioperative anesthesia care during subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation is still evolving. OBJECTIVE: To assess the feasibility and safety of S-ICD implantation with monitored anesthesia care (MAC) versus general anesthesia (GA) in a tertiary care center. METHODS: This is a single-center retrospective study of patients undergoing S-ICD implantation between October 2012 and May 2019. Patients were categorized into MAC and GA group based on the mode of anesthesia. Procedural success without escalation to GA was the primary endpoint of the study, whereas intraprocedural hemodynamics, need of pharmacological support for hypotension and bradycardia, length of the procedure, stay in the post-anesthesia care unit, and postoperative pain were assessed as secondary endpoints. RESULTS: The study comprises 287 patients with MAC in 111 and GA in 176 patients. Compared to MAC, patients in GA group were younger and had a higher body mass index. All patients had successful S-ICD implantation. Only one patient (0.9%) in the MAC group was converted to GA. Despite a similar baseline heart rate (HR) and mean arterial blood pressure (MAP) in both groups, patients with GA had significantly lower HR and MAP during the procedure and more frequently required pharmacological hemodynamic support. Length of the procedure, stay in the postanesthesia care unit, and postoperative pain was similar in both groups. CONCLUSION: This retrospective experience suggests that implantation of S-ICD is feasible and safe with MAC. Use of GA is associated with more frequent administration of hemodynamic drugs during S-ICD implantation.

Pulmonary cuff dysfunction after lung transplant surgery: A systematic review of the evidence and analysis of its clinical implications.

BACKGROUND: Pulmonary cuff dysfunction, either due to pulmonary vein obstruction, pulmonary vein stenosis, or pulmonary vein thrombosis, is an uncommon, yet serious complication after lung transplantation. Although there have been numerous reports of its occurrence, there is little consensus regarding the hemodynamic parameters associated with its presentation and diagnostic considerations. This systematic review summarizes the evidence surrounding pulmonary cuff dysfunction after lung transplantation surgery and empirically analyzes its implications. METHODS: Databases were examined for all articles and abstracts reporting on pulmonary cuff dysfunction. Data collected included: number of patients studied; patients' characteristics; incidences of pulmonary vein stenosis and pulmonary vein thrombosis; and timing and imaging modality utilized for diagnosis. RESULTS: Thirty-four full-text citations were included in this review. The point prevalence of pulmonary vein stenosis and thrombosis were 1.4% and 2.5%, respectively. The peak pulmonary cuff velocity associated with dysfunction was found to be 1.59 ± 0.66 m/sec. The diameter of the dysfunctional pulmonary vein was noted to be 0.48 ± 0.20 cm. The majority of diagnoses were made in the early post-operative period using transesophageal echocardiography. Overall, 41.3% of patients (26 of 63) required emergent procedural reintervention, and 32% of patients (20 of 63) diagnosed with pulmonary cuff dysfunction died during their hospital stay. CONCLUSIONS: This systematic review underscores the importance of identifying pulmonary cuff dysfunction after lung transplant surgery, and the usefulness of transesophageal echocardiography for detection of this complication. The clinical implications of these results warrant the further development of identification and management strategies for lung transplant patients.

Cytotoxic effector function of CD4-independent, CD8(+) T cells is mediated by TNF-α/TNFR.

BACKGROUND: Liver parenchymal cell allografts initiate both CD4-dependent and CD4-independent, CD8(+) T cell-mediated acute rejection pathways. The magnitude of allospecific CD8(+) T cell in vivo cytotoxic effector function is maximal when primed in the presence of CD4(+) T cells. The current studies were conducted to determine if and how CD4(+) T cells might influence cytotoxic effector mechanisms. METHODS: Mice were transplanted with allogeneic hepatocytes. In vivo cytotoxicity assays and various gene-deficient recipient mice and target cells were used to determine the development of Fas-, TNF-α-, and perforin-dependent cytotoxic effector mechanisms after transplantation. RESULTS: CD8(+) T cells maturing in CD4-sufficient hepatocyte recipients develop multiple (Fas-, TNF-α-, and perforin-mediated) cytotoxic mechanisms. However, CD8(+) T cells, maturing in the absence of CD4(+) T cells, mediate cytotoxicity and transplant rejection that is exclusively TNF-α/TNFR-dependent. To determine the kinetics of CD4-mediated help, CD4(+) T cells were adoptively transferred into CD4-deficient mice at various times posttransplant. The maximal influence of CD4(+) T cells on the magnitude of CD8-mediated in vivo allocytotoxicityf occurs within 48 hours. CONCLUSION: The implication of these studies is that interference of CD4(+) T cell function by disease or immunotherapy will have downstream consequences on both the magnitude of allocytotoxicity as well as the cytotoxic effector mechanisms used by allospecific CD8(+) cytolytic T cells.