Quantitative aortography for assessment of aortic regurgitation in the era of percutaneous aortic valve replacement.

Paravalvular leak (PVL) is a shortcoming that can erode the clinical benefits of transcatheter valve replacement (TAVR) and therefore a readily applicable method (aortography) to quantitate PVL objectively and accurately in the interventional suite is appealing to all operators. The ratio between the areas of the time-density curves in the aorta and left ventricular outflow tract (LVOT-AR) defines the regurgitation fraction (RF). This technique has been validated in a mock circulation; a single injection in diastole was further tested in porcine and ovine models. In the clinical setting, LVOT-AR was compared with trans-thoracic and trans-oesophageal echocardiography and cardiac magnetic resonance imaging. LVOT-AR > 17% discriminates mild from moderate aortic regurgitation on echocardiography and confers a poor prognosis in multiple registries, and justifies balloon post-dilatation. The LVOT-AR differentiates the individual performances of many old and novel devices and is being used in ongoing randomized trials and registries.

Training Anesthesiology Residents to Care for the Traumatically Injured in the United States.

Training and education for trauma anesthesiology have been predicated on 2 primary pathways: learning through peripheral "complex, massive transfusion cases"-an assumption that is flawed due to the unique demands, skills, and knowledge of trauma anesthesiology-or learning through experiential education, which is also incomplete due to its unpredictable and variable exposure. Residents may receive training from senior physicians who may not maintain a trauma-focused continuing medical education. Further compounding the issue is the lack of fellowship-trained clinicians and standardized curricula. The American Board of Anesthesiology (ABA) provides a section for trauma education in its Initial Certification in Anesthesiology Content Outline. However, many trauma-related topics also fall under other subspecialties, and the outline excludes "nontechnical" skills. This article focuses on the training of anesthesiology residents and proposes a tier-based approach to teaching the ABA outline by including lectures, simulation, problem-based learning discussions, and case-based discussions that are proctored in conducive environments by knowledgeable facilitators.

Performance assessment of intravenous catheters for massive transfusion: A pragmatic in vitro study.

BACKGROUND: Rapid infusion of warmed blood products is the cornerstone of trauma resuscitation and treatment of surgical and obstetric massive hemorrhage. Integral to optimizing this delivery is selection of an intravenous (IV) catheter and use of a rapid infusion device (RID). We investigated which IV catheter and RID system enabled the greatest infusion rate of blood products and the governing catheter characteristics. STUDY DESIGN AND METHODS: The maximum flow rates of nine IV catheters were measured while infusing a mixture of packed red blood cells and fresh frozen plasma at a 1:1 ratio using a RID with and without a patient line extension. To account for IV catheters that achieved the RID's maximum 1000 ml/min, the conductance of each infusion circuit configuration was calculated. RESULTS: IV catheters of 7-Fr caliber or higher reached the maximum pressurized flow rate. The 9-Fr multi-lumen access catheter (MAC) achieved the greatest conductance, over sevenfold greater than the 18 g peripheral catheter (4.6 vs. 0.6 ml/min/mmHg, p < .001). Conductance was positively correlated with internal radius (ß = 1.098, 95% CI 4.286-5.025, p < .001) and negatively correlated with length (ß= - 0.495, 95% CI -0.007 to 0.005, p < .001). Use of an extension line (ß= - 0.094, 95% CI -0.505 to -0.095, p = .005) was independently associated with reduced conductance in large caliber catheters. CONCLUSION: Short, large-diameter catheters provided the greatest infusion rates of massive transfusion blood products for the least pressure. For patients requiring the highest transfusion flow rates, extension tubing should be avoided when possible.

Aerosol Retention Characteristics of Barrier Devices.

BACKGROUND: Disease severity in coronavirus disease 2019 (COVID-19) may be associated with inoculation dose. This has triggered interest in intubation barrier devices to block droplet exposure; however, aerosol protection with these devices is not known. This study hypothesized that barrier devices reduce aerosol outside of the barrier. METHODS: Aerosol containment in closed, semiclosed, semiopen, and open barrier devices was investigated: (1) "glove box" sealed with gloves and caudal drape, (2) "drape tent" with a drape placed over a frame, (3) "slit box" with armholes and caudal end covered by vinyl slit diaphragms, (4) original "aerosol box," (5) collapsible "interlocking box," (6) "simple drape" over the patient, and (7) "no barrier." Containment was investigated by (1) vapor instillation at manikin's right arm with video-assisted visual evaluation and (2) submicrometer ammonium sulfate aerosol particles ejected through the manikin's mouth with ventilation and coughs. Samples were taken from standardized locations inside and around the barriers using a particle counter and a mass spectrometer. Aerosol evacuation from the devices was measured using standard hospital suction, a surgical smoke evacuator, and a Shop-Vac. RESULTS: Vapor experiments demonstrated leakage via arm holes and edges. Only closed and semiclosed devices and the aerosol box reduced aerosol particle counts (median [25th, 75th percentile]) at the operator's mouth compared to no barrier (combined median 29 [-11, 56], n = 5 vs. 157 [151, 166], n = 5). The other barrier devices provided less reduction in particle counts (133 [128, 137], n = 5). Aerosol evacuation to baseline required 15 min with standard suction and the Shop-Vac and 5 min with a smoke evacuator. CONCLUSIONS: Barrier devices may reduce exposure to droplets and aerosol. With meticulous tucking, the glove box and drape tent can retain aerosol during airway management. Devices that are not fully enclosed may direct aerosol toward the laryngoscopist. Aerosol evacuation reduces aerosol content inside fully enclosed devices. Barrier devices must be used in conjunction with body-worn personal protective equipment.

Difficult Retrieval of a Broken Catheter From a Total Implantable Venous Access Device.

A broken TIVAD catheter segment was discovered lodged within the right ventricle of a man presenting with chest pain. The catheter removal is detailed.

Medical student/student doctor access to patients in an emergency department.

OBJECTIVES: To determine the proportion of patients in a teaching hospital ED who are available to medical students; identify barriers to student access to patients; and determine whether patients are more likely to be accessible if the term student doctor is used rather than medical student. METHODS: Repeated cross-sectional study of the ED of a tertiary teaching hospital. Interviews were attempted with all patients in the ED during six 4 h periods. Outcome measures included: number of patients present and accessible to students; present but inaccessible, absent or unfit to be seen for clinical reasons; number of patients consenting to history, physical examination and certain procedures; and difference in patient consent between the terms 'medical student' and 'student doctor'. RESULTS: Overall, 180 of 450 (40.0%) patients completed the interview, 72 (16.0%) were able to be observed only, and 198 (44.0%) were not suitable for interview or observation. The common reasons for patient unsuitability were: physically not available (60%), being assessed by a health professional or undergoing a procedure (13.0%) altered mental status (7.4%), unstable or terminally ill (5.2%); refusal to participate in the study (4.8%), or dangerous or under arrest (4.1%). No significant differences were found in patient willingness to undergo clinical skills from 'student doctors' compared with 'medical students'. CONCLUSION: A minimum 40% of patients in a tertiary ED are accessible for student learning, with high proportions of patients accepting of students practising supervised history-taking, physical examination, and most less-invasive procedural skills.