Modification of a domiciliary ventilator to increase FiO2: an off-label modification which may be of value in COVID-19.

Although nasal continuous positive airway pressure or non-invasive ventilation is used to manage some patients with acute lung injury due to COVID-19, such patients also demonstrate increased minute ventilation which makes it hard, if the device is used in line with the manufacturer's instructions, to achieve adequate oxygen delivery. In addition, if a hospital contains many such patients, then it is possible that the oxygen requirements will exceed infrastructure capacity. Here we describe a simple modification of two exemplar ventilators normally used for domiciliary ventilation, which substantially increased the fraction of inspired oxygen (FiO2) delivered.

Pulmonary Angiopathy in Severe COVID-19: Physiologic, Imaging, and Hematologic Observations.

Rationale: Clinical and epidemiologic data in coronavirus disease (COVID-19) have accrued rapidly since the outbreak, but few address the underlying pathophysiology.Objectives: To ascertain the physiologic, hematologic, and imaging basis of lung injury in severe COVID-19 pneumonia.Methods: Clinical, physiologic, and laboratory data were collated. Radiologic (computed tomography (CT) pulmonary angiography [n = 39] and dual-energy CT [DECT, n = 20]) studies were evaluated: observers quantified CT patterns (including the extent of abnormal lung and the presence and extent of dilated peripheral vessels) and perfusion defects on DECT. Coagulation status was assessed using thromboelastography.Measurements and Results: In 39 consecutive patients (male:female, 32:7; mean age, 53 ± 10 yr [range, 29-79 yr]; Black and minority ethnic, n = 25 [64%]), there was a significant vascular perfusion abnormality and increased physiologic dead space (dynamic compliance, 33.7 ± 14.7 ml/cm H2O; Murray lung injury score, 3.14 ± 0.53; mean ventilatory ratios, 2.6 ± 0.8) with evidence of hypercoagulability and fibrinolytic "shutdown". The mean CT extent (±SD) of normally aerated lung, ground-glass opacification, and dense parenchymal opacification were 23.5 ± 16.7%, 36.3 ± 24.7%, and 42.7 ± 27.1%, respectively. Dilated peripheral vessels were present in 21/33 (63.6%) patients with at least two assessable lobes (including 10/21 [47.6%] with no evidence of acute pulmonary emboli). Perfusion defects on DECT (assessable in 18/20 [90%]) were present in all patients (wedge-shaped, n = 3; mottled, n = 9; mixed pattern, n = 6).Conclusions: Physiologic, hematologic, and imaging data show not only the presence of a hypercoagulable phenotype in severe COVID-19 pneumonia but also markedly impaired pulmonary perfusion likely caused by pulmonary angiopathy and thrombosis.

COVID-19 Pulmonary Failure and Extracorporeal Membrane Oxygenation: First Experience from Three European Extracorporeal Membrane Oxygenation Centers.

On April 17, 2020, a coronavirus disease 2019 (COVID-19) webinar was held by selected international experts in the field of intensive care and specialized respiratory ECMO centers from Germany, Italy, Spain, and the United Kingdom, which was hosted by the German Heart Centre Berlin/Charité. The experts shared their experience about the treatment of 42 patients with severe acute respiratory failure requiring venovenous extracorporeal membrane oxygenation (VV-ECMO). Patients were predominantly male (male-to-female ratio: 3:1), with a mean age of 51 years (range: 25-73 years). VV-ECMO support was indicated in 30% of the ventilated COVID-19 patients. The mean time requiring mechanical ventilation was 16.5 days, with a mean duration of ECMO support of 10.6 days. At the time of the webinar, a total of 17 patients had already been decannulated from ECMO, whereas six died with multiorgan failure. 18 patients remained on ECMO, with their final outcomes unknown at the time of the webinar. Hospital mortality was 25.6% (as of April 17, 2020). In this respect, VV-ECMO, provided by expert centers, is a recognized and validated mode of advanced life-support during the recent COVID-19 pandemic with good outcomes.

Veno-arterial mechanical support as bridge to surgery in a patient with severe aortic regurgitation: a case report.

In this case report, we describe the successful application of veno-arterial extracorporeal membrane oxygenation support in a young patient with severe aortic regurgitation caused by a blocked mechanical valve. In this situation, extracorporeal membrane oxygenation mechanical support was used as a bridge to the prompt replacement of the diseased valve. Aortic regurgitation is commonly recognized as a contraindication to extracorporeal membrane oxygenation support because of the risk of ventricular distension, pulmonary oedema and further organ failure. However, in certain cases and with a rapid decision making, extracorporeal membrane oxygenation can be used as a bridge to treatment and recovery.

Intracranial Hemorrhage and Early Mortality in Patients Receiving Extracorporeal Membrane Oxygenation for Severe Respiratory Failure.

Intracranial hemorrhage (ICH) is a serious complication in patients receiving veno-venous extracorporeal membrane oxygenation (VV-ECMO) and is associated with high mortality. It is unknown whether ICH may be a consequence of the ECMO or of an underlying disease. The authors first aimed to assess the incidence of ICH at initiation and during the course of VV-ECMO and its associated mortality. The second aim was to identify clinical and laboratory measures that could predict the development of ICH in severe respiratory failure. Data were collected from a total number of 165 patients receiving VV-ECMO from January, 2012 to December, 2016 in a single tertiary center and treated according to a single protocol. Only patients who had a brain computed tomography within 24 hours of initiation of ECMO (n = 149) were included for analysis. The prevalence and incidence of ICH at initiation and during the course of VV-ECMO (at median 9 days) were 10.7% (16/149) and 5.2% (7/133), respectively. Thrombocytopenia and reduced creatinine clearance (CrCL) were independently associated with increased risk of ICH on admission; odds ratio (95% confidence interval): 22.6 (2.6-99.5), and 10.8 (5.6-16.2). Only 30-day (not 180-day) mortality was significantly higher in patients with ICH on admission versus those without (37.5% [6/16] vs 16.4% [22/133]; p = 0.03 and 43.7% [7/16] vs 26.3% [35/133]; p = 0.15, respectively). Reduced CrCL and thrombocytopenia were associated with ICH at initiation of VV-ECMO. The higher incidence of ICH at initiation suggests it is more closely related to the severity of the underlying lung injury than to the VV-ECMO itself. ICH at VV-ECMO initiation was associated with early mortality.

Taxine alkaloid poisoning successfully supported with venoarterial extracorporeal membrane oxygenation: a case report.

BACKGROUND: Ingestion of the berries of the European yew tree can result in fatal cardiac arrhythmias. CASE SUMMARY: A 53-year-old female presented to our emergency department following ingestion of ∼200 European yew tree berries. At presentation, she was in cardiogenic shock due to a mixture of tachy- and bradyarrhythmias including ventricular tachycardia, atrial fibrillation with slow ventricular response and prolonged ventricular conduction, and periods of asystole. She was referred to a specialist cardiac centre and promptly established on mechanical circulatory support with venoarterial extracorporeal membrane oxygenation (V-A ECMO) by a retrieval team. Following resolution of her arrhythmias, she was weaned from V-A ECMO after 4 days of support and was discharged home with full neurological recovery on Day 12. DISCUSSION: Poisoning can lead to acute reversible but potentially fatal cardiogenic shock. We believe that access to prompt initiation of V-A ECMO was key to this patient's survival.

Cardiohelp System use in school age children and adolescents at a center with interfacility mobile extracorporeal membrane oxygenation capability.

Cardiohelp System use for pediatric extracorporeal membrane oxygenation (ECMO) beyond the transport setting is sparsely described in literature. We report the use of Getinge's Cardiohelp System in children and integrated utilization of Mobile ECMO Retrieval Team (MERT) at an all-age specialized cardiorespiratory center. Electronic database of all patients under 16 years of age who received ECMO with use of the Cardiohelp System between January 2018 and March 2020 was retrospectively reviewed and analyzed for demographics, set-up, complications, and outcomes. Out of 41 patients, seven patients (four in middle childhood, three in early teenage) with median age of 10 years (range 8.8-15.6) were supported with use of Cardiohelp System. Median weight and height were 34 kg (range 28-53) and 145 cm (range 134-166) respectively. Initial ECMO deployment was veno-arterial (V-A) in five patients and veno-venous (V-V) in two. There were three interhospital transfers by our MERT, and 12 intrahospital transfers for interventions or imaging. The median ECMO therapy was 7 days (range 4-25), with standard 3/8-inch tubing and ECMO flow rate range at 56-100 mL/kg/min (1.89-5.0 LPM). There were two circuit changes and three reconfigurations of support. Two patients received continuous veno-venous hemofiltration via ECMO circuit. The 90-day and 180-day survival rates were 100% (including two heart transplants at day 7 and day 8). There were no transport-related or circuit-related complications during the 1750 h of Cardiohelp use. Cardiohelp System use is safe in pediatric patients for diverse application of ECMO support including inter- and intrahospital transfers.

Near-fatal Panton-Valentine leukocidin-positive Staphylococcus aureus pneumonia, shock and complicated extracorporeal membrane oxygenation cannulation: A case report.

BACKGROUND: Panton-Valentine leukocidin (PVL) is an exotoxin secreted by Staphylococcus aureus (S. aureus), responsible for skin and soft tissue infections. As a cause of severe necrotising pneumonia, it is associated with a high mortality rate. A rare entity, the epidemiology of PVL S. aureus (PVL-SA) pneumonia as a complication of influenza coinfection, particularly in young adults, is incompletely understood. CASE SUMMARY: An adolescent girl presented with haemoptysis and respiratory distress, deteriorated rapidly, with acute respiratory distress syndrome (ARDS) and profound shock requiring extensive, prolonged resuscitation, emergency critical care and venovenous extracorporeal membrane oxygenation (ECMO). Cardiac arrest and a rare complication of ECMO cannulation necessitated intra-procedure extracorporeal cardiopulmonary resuscitation, i.e., venoarterial ECMO. Coordinated infectious disease, microbiology and Public Health England engagement identified causative agents as PVL-SA and influenza A/H3N2 from bronchial aspirates within hours. Despite further complications of critical illness, the patient made an excellent recovery with normal cognitive function. The coordinated approach of numerous multidisciplinary specialists, nursing staff, infection control, specialist cardiorespiratory support, hospital services, both adult and paediatric and Public Health are testimony to what can be achieved to save life against expectation, against the odds. The case serves as a reminder of the deadly nature of PVL-SA when associated with influenza and describes a rare complication of ECMO cannulation. CONCLUSION: PVL-SA can cause severe ARDS and profound shock, with influenza infection. A timely coordinated multispecialty approach can be lifesaving.

Six Month Mortality in Patients with COVID-19 and Non-COVID-19 Viral Pneumonitis Managed with Veno-Venous Extracorporeal Membrane Oxygenation.

A significant proportion of patients with COVID-19 develop acute respiratory distress syndrome (ARDS) with high risk of death. The efficacy of veno-venous extracorporeal membrane oxygenation (VV-ECMO) for COVID-19 on longer-term outcomes, unlike in other viral pneumonias, is unknown. In this study, we aimed to compare the 6 month mortality of patients receiving VV-ECMO support for COVID-19 with a historical viral ARDS cohort. Fifty-three consecutive patients with COVID-19 ARDS admitted for VV-ECMO to the Royal Brompton Hospital between March 17, 2020 and May 30, 2020 were identified. Mortality, patient characteristics, complications, and ECMO parameters were then compared to a historical cohort of patients with non-COVID-19 viral pneumonia. At 6 months survival was significantly higher in the COVID-19 than in the non-COVID-19 viral pneumonia cohort (84.9% vs. 66.0%, p = 0.040). Patients with COVID-19 had an increased Murray score (3.50 vs. 3.25, p = 0.005), a decreased burden of organ dysfunction (sequential organ failure score score [8.76 vs. 10.42, p = 0.004]), an increased incidence of pulmonary embolism (69.8% vs. 24.5%, p < 0.001) and in those who survived to decannulation longer ECMO runs (19 vs. 11 days, p = 0.001). Our results suggest that survival in patients supported with EMCO for COVID-19 are at least as good as those treated for non-COVID-19 viral ARDS.

Multi-centre prospective internal and external evaluation of the Brompton Harefield Infection Score (BHIS).

BACKGROUND: Previously, we reported that the Brompton Harefield Infection Score (BHIS) accurately predicts surgical site infection (SSI) after coronary artery bypass grafting (CABG). The BHIS was developed using two-centre data and stratifies SSI risk into three groups based on female gender, diabetes or HbA1c > 7.5%, body mass index ≥ 35, left ventricular ejection fraction < 45% and emergency surgery. The purpose of this study was to prospectively evaluate BHIS internally as well as externally. METHODS: Multi-centre prospective evaluation involving three tertiary centres took place between October 2012 and November 2015. SSI was classified using the Public Health England protocol. Receiver operating characteristic (ROC) curves assessed predictive accuracy. RESULTS: Across the four hospital sites, 168 of 4308 (3.9%) CABG patients had a SSI. Categorising the hospitals by BHIS score revealed that 65% of all patients were low risk (BHIS 0-1), 26% were medium risk (BHIS 2-3) and 8% were high risk (BHIS ≥ 4). The area under the ROC curve was in the range of 0.702-0.785. Overall area under the ROC curve was 0.709. CONCLUSIONS: BHIS provides a novel, internally and externally evaluated score for a patient's risk of SSI after CABG. It enables clinicians to focus on strategies to prospectively identify high-risk patients and improve outcomes.

Endoscopic Conduit Harvest in Coronary Artery Bypass Grafting Surgery: An ISMICS Systematic Review and Consensus Conference Statements.

OBJECTIVE: The purpose of this consensus conference was to develop and update evidence-informed consensus statements and recommendations on harvesting saphenous vein and radial artery via an open as compared with endoscopic technique by systematically reviewing and performing a meta-analysis of randomized and nonrandomized clinical trials. METHODS: All randomized controlled trials and nonrandomized controlled trials included in the first the International Society for Minimally Invasive Cardiothoracic Surgery Consensus Conference and Statements, in 2005 up to November 30, 2015, were included in a systematic review and meta-analysis. Based on the resultant, 76 studies (23 randomized controlled trials and 53 nonrandomized controlled trials) on 281,459 patients analyzed, consensus statements, and recommendations were generated comparing the risks and benefits of endoscopic versus open conduit harvesting for patients undergoing coronary artery bypass grafting. RESULTS: Compared with open vein harvest, it is reasonable to perform endoscopic vein harvest of saphenous vein to reduce wound-related complications, postoperative length of stay, and outpatient wound management resources and to increase patient satisfaction (class I, level A). Based on the quality of the conduit and major adverse cardiac events as well as 6-month angiographic patency, endoscopic vein harvest was noninferior to open harvest. It is reasonable to perform endoscopic radial artery harvest to reduce wound-related complication and to increase patient satisfaction (class I, level B-R and B-NR, respectively) with reduction in major adverse cardiac events and noninferior patency rate at 1 and 3 to 5 years (class III, level B-R). CONCLUSIONS: Based on the consensus statements, the consensus panel recommends (class I, level B) that endoscopic saphenous vein and radial artery harvesting should be the standard of care for patients who require these conduits for coronary revascularization.

First hospital outbreak of the globally emerging Candida auris in a European hospital.

BACKGROUND: Candida auris is a globally emerging multidrug resistant fungal pathogen causing nosocomial transmission. We report an ongoing outbreak of C. auris in a London cardio-thoracic center between April 2015 and July 2016. This is the first report of C. auris in Europe and the largest outbreak so far. We describe the identification, investigation and implementation of control measures. METHODS: Data on C. auris case demographics, environmental screening, implementation of infection prevention/control measures, and antifungal susceptibility of patient isolates were prospectively recorded then analysed retrospectively. Speciation of C. auris was performed by MALDI-TOF and typing of outbreak isolates performed by amplified fragment length polymorphism (AFLP). RESULTS: This report describes an ongoing outbreak of 50 C. auris cases over the first 16 month (April 2015 to July 2016) within a single Hospital Trust in London. A total of 44 % (n = 22/50) patients developed possible or proven C. auris infection with a candidaemia rate of 18 % (n = 9/50). Environmental sampling showed persistent presence of the yeast around bed space areas. Implementation of strict infection and prevention control measures included: isolation of cases and their contacts, wearing of personal protective clothing by health care workers, screening of patients on affected wards, skin decontamination with chlorhexidine, environmental cleaning with chorine based reagents and hydrogen peroxide vapour. Genotyping with AFLP demonstrated that C. auris isolates from the same geographic region clustered. CONCLUSION: This ongoing outbreak with genotypically closely related C. auris highlights the importance of appropriate species identification and rapid detection of cases in order to contain hospital acquired transmission.

Determinants of successful endoscopic internal thoracic artery harvesting: a prospective analysis.

OBJECTIVE: Endoscopic internal thoracic artery (ITA) harvesting is employed during minimal-access coronary artery bypass grafting. To improve case selection, we prospectively analyzed our entire experience to identify variables that predict intraoperative conversion to sternotomy. METHODS: We performed a prospective study from September 1999 to November 2003 of 100 consecutive patients with an endoscopically harvested left ITA (LITA). Success was defined as an endoscopic dissection of the LITA sufficient to reach the anastomosis. Multivariate logistic regression analysis was performed to identify independent preoperative and procedural predictors of success. RESULTS: The measured parameters (mean +/- SD) were age (62 +/- 9 years), height (174 +/- 9 cm), weight (81 +/- 14 kg), and logistic Euroscore (2.0 +/- 1.7). Patients comprised 8 (8%) women, 17 (17%) with urgent operations, 42 (42%) with multiple vessel disease, 17 (17%) with a left ventricular ejection fraction <50%, 2 (2%) redo procedures, and 3 (3%) with pleural disease. The Zeus robot was used in 17 patients (17%). Eight-eight (88%) of the LITA were successfully harvested endoscopically. Among the 12 patients who underwent conversions, pleural adhesions were the most common finding (n = 4, 33%). One LITA was unusable. In the final multivariate model, lung disease was a negative predictor of successful endoscopic harvest (odds ratio, 0.13; 95% confidence interval, 0.02-0.63; P =.012). The variables of age, sex, left ventricular function, logistic Euroscore, operative priority, and use of the Zeus robot did not achieve statistical significance. CONCLUSIONS: Acceptable conversion rates and low conduit wastage are achievable during a unit's initial experience. Lung disease is associated with increased conversion frequency, and surgeons embarking on endoscopic harvesting should consider excluding these patients to improve their chances of success. Pleural adhesions increase the technical difficulty of surgery.

Improved recovery after the endoscopic atraumatic coronary artery bypass procedure compared with sternotomy for off-pump bypass of the left internal thoracic artery to the left anterior descending coronary artery: a case-matched study.

OBJECTIVE: The endoscopic atraumatic coronary artery bypass (endo-ACAB) procedure allows single-vessel coronary artery bypass grafting (CABG), avoiding sternotomy or thoracotomy. We set out to define the effect of this surgical approach on postoperative recovery, blood loss, and return to work. METHODS: We performed a case-control comparison of our first 29 endo-ACAB procedures for left anterior descending coronary artery (LAD) disease against 29 control patients, who underwent off-pump beating heart CABG via sternotomy for isolated LAD disease in the same institution. Control pairs were matched for age, sex, and ventricular function. RESULTS: In a matched population, endo-ACAB is associated with shorter postoperative ventilation times (6.2 hours versus 9.0 hours, P = .034) and hospital stays (5.3 nights versus 6.4 nights, P = .04), less blood loss (363.9 mL versus 570.3 mL, P = .017), and lower transfusion requirements. Endo-ACAB patients were more likely to return to employment and did so at a mean of 6.6 weeks earlier than sternotomy patients (P = .019). CONCLUSIONS: Endo-ACAB for grafting of the left internal mammary artery to the LAD is associated with reduced blood loss and faster postoperative recovery. Avoiding sternotomy appears to be a significant factor in recovery after beating heart single-vessel CABG surgery.

Outcomes after different non-sternotomy approaches to left single-vessel revascularization: a comparative study with up to 10-year follow-up.

OBJECTIVES: Various non-sternotomy approaches have been used for left internal mammary artery (LIMA) grafting in left single-vessel revascularization. The aim of this study was to evaluate the impact of three different non-sternotomy techniques on long-term outcomes after left single-vessel revascularization. METHODS: A total of 502 patients having single-vessel LAD disease treated from April 2003 to May 2013 by minimally invasive direct coronary artery bypass grafting (MIDCAB), endoscopically assisted coronary artery bypass grafting (EACAB) or robotically assisted direct coronary artery bypass grafting (RADCAB) were reviewed. In all cases, distal anastomoses were performed through anterolateral minithoracotomy incisions. In-hospital and long-term (10-year) outcomes were compared using standard and propensity score-adjusted analyses. RESULTS: One hundred and eighty-nine patients had MIDCAB, 76 had EACAB and 236 had RADCAB. After propensity score matching, RADCAB patients had significantly longer operative duration (P < 0.001), whereas MIDCAB and RADCAB patients had significantly higher incidence of postoperative angina over the follow-up (P = 0.034). The groups were comparable regarding in-hospital mortality and reintervention rate as well as incidence of myocardial infarction, reoperations, reinterventions and cardiac death. All groups showed comparable long-term survival (P = 0.943). CONCLUSIONS: MIDCAB, EACAB and RADCAB are associated with similar long-term survival and incidence of major adverse cardiac events (MACEs) in single-vessel surgical revascularization. However, the endoscopic approach was found to be free from the disadvantages of longer operating duration observed in RADCAB or higher incidence of angina and shorter freedom from MACEs observed in both MIDCAB and RADCAB groups.

A modified technique for insertion of dual lumen bicaval cannulae for venovenous extracorporeal membrane oxygenation.

PURPOSE: Venovenous extracorporeal membrane oxygenation is used increasingly in adults with severe acute reversible respiratory failure. Cannulation is associated with a risk of vascular damage or cardiac perforation. METHODS AND RESULTS: This report describes a modified technique of insertion for dual lumen bicaval cannulae. We have adopted the technique on 25 occasions and had no incidence of vascular damage or cardiac perforation. CONCLUSION: We suggest that the technique may mitigate the risk of guidewire looping during insertion of the dilators/cannula and thereby reduce the risk of perforation of the right ventricle.

The left axillary artery--a new approach for transcatheter aortic valve implantation.

OBJECTIVE: Transcatheter aortic valve implantation (TAVI) is an alternative treatment for aortic stenosis in selected cases, but requires appropriate vascular access. We report our initial clinical experience with a novel endovascular approach for TAVI. METHODS: Between 1 April 2007 and 31 August 2008, 48 patients underwent TAVI at our institution. Of these, eight patients (17%) were deemed to be best served through direct surgical exposure of the left axillary artery rather than a trans-femoral or TA approach. RESULTS: Procedural success was achieved in seven of eight cases. In one patient the axillary artery was too small to accept the 18 French sheath. In the remaining seven, the device was implanted without major complication and with only trivial paravalvular aortic regurgitation. The in-hospital mortality was 0%. The 30-day mortality was 12.5% (one patient). There was one localised dissection at the origin of the vertebral artery. There was one late pericardial effusion and a permanent pacemaker was implanted in five patients. CONCLUSIONS: TAVI can be performed through a left axillary artery approach. This is a technically simple procedure and, in this small initial clinical experience, was performed with encouraging results. It is a realistic option in patients in whom neither the trans-femoral or trans-apical approaches are optimal.