Assessing feasibility of proposed extracorporeal cardiopulmonary resuscitation programmes for out-of-hospital cardiac arrest in Scotland via geospatial modelling.

BACKGROUND: Extracorporeal cardiopulmonary resuscitation (ECPR) can improve survival for refractory out-of-hospital cardiac arrest (OHCA). We sought to assess the feasibility of a proposed ECPR programme in Scotland, considering both in-hospital and pre-hospital implementation scenarios. METHODS: We included treated OHCAs in Scotland aged 16-70 between August 2018 and March 2022. We defined those clinically eligible for ECPR as patients where the initial rhythm was ventricular fibrillation, ventricular tachycardia, or pulseless electrical activity, and where pre-hospital return of spontaneous circulation was not achieved. We computed the call-to-ECPR access time interval as the amount of time from emergency medical service (EMS) call reception to either arrival at an ECPR-ready hospital or arrival of a pre-hospital ECPR crew. We determined the number of patients that had access to ECPR within 45 min, and estimated the number of additional survivors as a result. RESULTS: A total of 6,639 OHCAs were included in the geospatial modelling, 1,406 of which were eligible for ECPR. Depending on the implementation scenario, 52.9-112.6 (13.8-29.4%) OHCAs per year had a call-to-ECPR access time within 45 min, with pre-hospital implementation scenarios having greater and earlier access to ECPR for OHCA patients. We further estimated that an ECPR programme in Scotland would yield 11.8-28.2 additional survivors per year, with the pre-hospital implementation scenarios yielding higher numbers. CONCLUSION: An ECPR programme for OHCA in Scotland could provide access to ECPR to a modest number of eligible OHCA patients, with pre-hospital ECPR implementation scenarios yielding higher access to ECPR and higher numbers of additional survivors.

EPidemiology Of Cardiogenic sHock in Scotland (EPOCHS): A multicentre, prospective observational study of the prevalence, management and outcomes of cardiogenic shock in Scotland.

Background: Despite high rates of cardiovascular disease in Scotland, the prevalence and outcomes of patients with cardiogenic shock are unknown. Methods: We undertook a prospective observational cohort study of consecutive patients with cardiogenic shock admitted to the intensive care unit (ICU) or coronary care unit at 13 hospitals in Scotland for a 6-month period. Denominator data from the Scottish Intensive Care Society Audit Group were used to estimate ICU prevalence; data for coronary care units were unavailable. We undertook multivariable logistic regression to identify factors associated with in-hospital mortality. Results: In total, 247 patients with cardiogenic shock were included. After exclusion of coronary care unit admissions, this comprised 3.0% of all ICU admissions during the study period (95% confidence interval [CI] 2.6%-3.5%). Aetiology was acute myocardial infarction (AMI) in 48%. The commonest vasoactive treatment was noradrenaline (56%) followed by adrenaline (46%) and dobutamine (40%). Mechanical circulatory support was used in 30%. Overall in-hospital mortality was 55%. After multivariable logistic regression, age (odds ratio [OR] 1.04, 95% CI 1.02-1.06), admission lactate (OR 1.10, 95% CI 1.05-1.19), Society for Cardiovascular Angiographic Intervention stage D or E at presentation (OR 2.16, 95% CI 1.10-4.29) and use of adrenaline (OR 2.73, 95% CI 1.40-5.40) were associated with mortality. Conclusions: In Scotland the prevalence of cardiogenic shock was 3% of all ICU admissions; more than half died prior to discharge. There was significant variation in treatment approaches, particularly with respect to vasoactive support strategy.

GEospatial aNalysis of ExtRacorporeal membrane oxygenATion in Europe (GENERATE).

INTRODUCTION: A cross-sectional survey GENERATE (GEospatial aNalysis of ExtRacorporeal membrane oxygenATion in Europe) initiated on behalf of the European chapter of the Extracorporeal Life Support Organization (EuroELSO), aims to provide a systematic, detailed description of contemporary Extracorporeal Life Support (ECLS) provision in Europe, map the spatial distribution of ECLS centers, and the accessibility of ECLS. METHODS: Structured data collection forms were used to create a narrative description of ECLS provision in EuroELSO affiliated countries. This consisted of both center-specific data and relevant national infrastructure. Data was provided by a network of local and national representatives. Spatial accessibility analysis was conducted where appropriate geographical data were available. RESULTS: 281 centers from 37 countries affiliated to EuroELSO were included in the geospatial analysis and demonstrate heterogeneous patterns of ECLS provision. Accessibility of ECLS services within 1 hour of drive-time is available for 50% of the adult population in 8 of 37 countries (21.6%). This proportion is reached within 2 hours in 21 of 37 countries (56.8%) and within 3 hours in 24 of 37 countries (64.9%). For pediatric centers, accessibility is similar with 9 of 37 countries (24.3%) reached the covering of 50% of the population aged 0-14 within 1 hour and 23 of 37 countries (62.2%) within 2 hours and 3 hours. CONCLUSIONS: ECLS services are accessible in most of the European countries, but their provision differs across the continent. There is still no solid evidence given regarding the optimal ECLS provision model. The spatial disparity in ECLS provision demonstrated in our analysis requires governments, healthcare professionals and policy makers to consider how to develop existing provision to accommodate the anticipated increase in need for time critical access to this advanced support modality.

Medical High Dependency Unit series, Article 3: Respiratory Support in the MHDU.

Acute respiratory failure is a life threatening condition encountered by Acute Physicians; additional non-invasive support can be provided within the medical high dependency unit (MHDU). Acute Physicians should strive to be experts in the investigation, management and support of patients with acute severe respiratory failure. This article outlines key management principles in these areas and explores common pitfalls.

Severe Respiratory Failure, Extracorporeal Membrane Oxygenation, and Intracranial Hemorrhage.

OBJECTIVES: For patients supported with veno-venous extracorporeal membrane oxygenation, the occurrence of intracranial hemorrhage is associated with a high mortality. It is unclear whether intracranial hemorrhage is a consequence of the extracorporeal intervention or of the underlying severe respiratory pathology. In a cohort of patients transferred to a regional severe respiratory failure center that routinely employs admission brain imaging, we sought 1) the prevalence of intracranial hemorrhage; 2) survival and neurologic outcomes; and 3) factors associated with intracranial hemorrhage. DESIGN: A single-center, retrospective, observational cohort study. SETTING: Tertiary referral severe respiratory failure center, university teaching hospital. PATIENTS: Patients admitted between December 2011 and February 2016. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: Three hundred forty-two patients were identified: 250 managed with extracorporeal support and 92 managed using conventional ventilation. The prevalence of intracranial hemorrhage was 16.4% in extracorporeal membrane oxygenation patients and 7.6% in conventionally managed patients (p = 0.04). Multivariate analysis revealed factors independently associated with intracranial hemorrhage to be duration of ventilation (d) (odds ratio, 1.13 [95% CI, 1.03-1.23]; p = 0.011) and admission fibrinogen (g/L) (odds ratio, 0.73 [0.57-0.91]; p = 0.009); extracorporeal membrane oxygenation was not an independent risk factor (odds ratio, 3.29 [0.96-15.99]; p = 0.088). In patients who received veno-venous extracorporeal membrane oxygenation, there was no significant difference in 6-month survival between patients with and without intracranial hemorrhage (68.3% vs 76.0%; p = 0.350). Good neurologic function was observed in 92%. CONCLUSIONS: We report a higher prevalence of intracranial hemorrhage than has previously been described with high level of neurologically intact survival. Duration of mechanical ventilation and admission fibrinogen, but not exposure to extracorporeal support, are independently associated with intracranial hemorrhage.

Rapid response systems: recognition and rescue of the deteriorating hospital patient.

The last 25 years have witnessed significant change in the approach to the deteriorating patient. This article reviews and discusses the merits and drawbacks of the various systems used across the world.

A Retrospective Observational Case Series of Low-Flow Venovenous Extracorporeal Carbon Dioxide Removal Use in Patients with Respiratory Failure.

We aimed to describe the use of venovenous extracorporeal carbon dioxide removal (ECCO2R) in patients with hypercapnic respiratory failure. We performed a retrospective case note review of patients admitted to our tertiary regional intensive care unit and commenced on ECCO2R from August 2013 to February 2015. Fourteen patients received ECCO2R. Demographic data, physiologic data (including pH and partial pressure of carbon dioxide in arterial blood [PaCO2]) when starting ECCO2R (t = 0), at 4 hourly intervals for the first 24 hours, then at 24 hour intervals until cessation of ECCO2R, and overall outcome were recorded. Patients are reported separately depending on whether the indication for ECCO2R was an exacerbation of chronic obstructive pulmonary disease (COPD; n = 5), or acute respiratory distress syndrome (ARDS) and persisting hypercapnoea (n = 9). Patients were managed with ECCO2R (Hemolung, ALung Inc, Pittsburgh, PA). Median duration of ECCO2R was 5 days. Four complications related to ECCO2R were reported, none resulting in serious adverse outcomes. Ten patients were discharged from intensive care unit (ICU) alive. A statistically significant improvement in pH (p = 0.012) was demonstrated. Our observational series of ECCO2R shows that this technique can be safely used to achieve therapeutic goals in patients requiring lung protection, and in COPD, in line with current publications in this area.

Perioperative Extracorporeal Membrane Oxygenation to Facilitate Lung Resection After Contralateral Pneumonectomy.

A 75-year-old man previously underwent pneumonectomy for lung cancer. He subsequently had colorectal adenocarcinoma, and resection of metastases from his remaining lung was performed. Venovenous extracorporeal membrane oxygenation was used for perioperative respiratory support to facilitate intraoperative deflation of the remaining lung and optimization of the surgical field. Venovenous extracorporeal membrane oxygenation was continued postoperatively, allowing immediate extubation, thus avoiding strain on suture lines. Advantages, and potential risks, of venovenous extracorporeal membrane oxygenation for thoracic surgery are discussed.

Retrospective Observational Review of Percutaneous Cannulation for Extracorporeal Membrane Oxygenation.

Cannulation is a potentially complex event in the conduct of venovenous extracorporeal membrane oxygenation (VV-ECMO) for patients with severe respiratory failure. The purpose of this article is to describe our approach to cannulation and its complications. A single-center, retrospective, observational cohort, electronic note review study of patients commenced on VV-ECMO for severe respiratory failure. We identified 348 cannulae placed in 179 patients commenced on VV-ECMO from December 2011 to March 2015. All cannulations were successful. There were no deaths related to cannulation, and complications included one arterial injury, one cardiac tamponade, two cases of venous insufficiency, and five cannula site infections. Percutaneous cannulation for VV-ECMO can be achieved with a high degree of success and low complication rate by intensivists using ultrasound and fluoroscopic guidance.

Intracardiac Right-to-Left Shunt Impeding Liberation From Veno-Venous Extracorporeal Membrane Oxygenation: Two Case Studies.

OBJECTIVES: Veno-venous extracorporeal membrane oxygenation is an increasingly used form of advanced respiratory support, but its effects on the physiology of the right heart are incompletely understood. We seek to illustrate the impact of veno-venous extracorporeal membrane oxygenation return blood flow upon the right atrium by considering the physiologic effects during interatrial shunting. PATIENTS: Two veno-venous extracorporeal membrane oxygenation patients in whom an extracorporeal membrane oxygenation induced right-to-left interatrial shunt appears to have created a barrier to liberation from extracorporeal support. CONCLUSIONS: Veno-venous extracorporeal membrane oxygenation return flow generates a high-pressure jet that has potential to exert focal pressure upon the intra-atrial septum. In patients with potential for interatrial flow, this may lead to a right-to-left shunt, which becomes physiologically apparent only when sweep gas flow is ceased.

CRITICAL CARE ECHO ROUNDS: Extracorporeal membrane oxygenation.

UNLABELLED: Extracorporeal membrane oxygenation (ECMO) is an advanced form of organ support indicated in selected cases of severe cardiovascular and respiratory failure. Echocardiography is an invaluable diagnostic and monitoring tool in all aspects of ECMO support. The unique nature of ECMO, and its distinct effects upon cardio-respiratory physiology, requires the echocardiographer to have a sound understanding of the technology and its interaction with the patient. In this article, we introduce the key concepts underpinning commonly used modes of ECMO and discuss the role of echocardiography. CASE: A 38-year-old lady, with no significant past medical history, was admitted to her local hospital with group A Streptococcal pneumonia. Rapidly progressive respiratory failure ensued and, despite intubation and maximal ventilatory support, adequate oxygenation proved impossible. She was attended by the regional severe respiratory failure service who established her on veno-venous (VV)-ECMO for respiratory support. Systemic oxygenation improved; however, significant cardiovascular compromise was encountered and echocardiography demonstrated a severe septic cardiomyopathy (ejection fraction <15%, aortic velocity time integral 5.9 cm and mitral regurgitation dP/dt 672 mmHg/s). Her ECMO support was consequently converted to a veno-veno-arterial configuration, thus providing additional haemodynamic support. As the sepsis resolved, arterial ECMO support was weaned under echocardiographic guidance; subsequent resolution of intrinsic respiratory function allowed the weaning of VV-ECMO support. The patient was liberated from ECMO 7 days after hospital admission.

Thermoregulatory central venous catheter-associated thrombus - echocardiographic detection and novel approach to management.

An extensive caval thrombus was incidentally detected in a neurosurgical patient by clinician-delivered critical care echocardiography. Recent intracranial haemorrhage prevented therapeutic anticoagulation; the very proximal nature of the thrombus precluded standard deployment of an inferior vena cava filter. We describe the novel radiological technique employed to manage the thrombus, and examine whether a thermoregulatory central venous catheter inserted as part of standard neuro-critical care may have contributed to the risk and extent of the caval thrombus.

CRITICAL CARE ECHO ROUNDS: Haemodynamic instability.

UNLABELLED: The use of echocardiography, whilst well established in cardiology, is a relatively new concept in critical care medicine. However, in recent years echocardiography's potential as both a diagnostic tool and a form of advanced monitoring in the critically ill patient has been increasingly recognised. In this series of Critical Care Echo Rounds, we explore the role of echocardiography in critical illness, beginning here with haemodynamic instability. We discuss the pathophysiology of the shock state, the techniques available to manage haemodynamic compromise, and the unique role which echocardiography plays in this complex process. CASE: A 69-year-old female presents to the emergency department with a fever, confusion and pain on urinating. Her blood pressure on arrival was 70/40, with heart rate of 117 bpm Despite 3 l of i.v. fluid she remained hypotensive. A central venous catheter was inserted and noradrenaline infusion commenced, and she was admitted to the intensive care unit for management of her shock state. At 6 h post admission, she was on high dose of noradrenaline (0.7 µg/kg per min) but blood pressure remained problematic. An echocardiogram was requested to better determine her haemodynamic state.

CRITICAL CARE ECHO ROUNDS: Echo in cardiac arrest.

UNLABELLED: Management of medical cardiac arrest is challenging. The internationally agreed approach is highly protocolised with therapy and diagnosis occurring in parallel. Early identification of the precipitating cause increases the likelihood of favourable outcome. Echocardiography provides an invaluable diagnostic tool in this context. Acquisition of echo images can be challenging in cardiac arrest and should occur in a way that minimises disruption to cardiopulmonary resuscitation (CPR). In this article, the reversible causes of cardiac arrest are reviewed with associated echocardiography findings. CASE: A 71-year-old patient underwent right upper lobectomy for lung adenocarcinoma. On the 2nd post-operative day, he developed respiratory failure with rising oxygen requirement and right middle and lower lobe collapse and consolidation on chest X-ray. He was commenced on high-flow oxygen therapy and antibiotics. His condition continued to deteriorate and on the 3rd post-operative day he was intubated and mechanically ventilated. Six hours after intubation, he became suddenly hypotensive with a blood pressure of 50 systolic and then lost cardiac output. ECG monitoring showed pulseless electrical activity. CPR was commenced and return of circulation occurred after injection of 1 mg of adrenaline. Focused echocardiography was performed, which demonstrated signs of massive pulmonary embolism. Thrombolytic therapy with tissue plasminogen activator was given and his condition stabilised.

Zebra in the intensive care unit: a metacognitive reflection on misdiagnosis.

Misdiagnosis of the cause of illness in critically ill patients is common, and a major cause of morbidity and mortality. We reflect upon a misdiagnosis that occurred in the intensive care unit of a metropolitan teaching hospital, and highlight the susceptibility of medical decision making to error. We examine recent advances in cognitive theory and how these apply to diagnosis. We discuss the vulnerability of such processes and - with particular reference to our case - why even knowledgeable and diligent clinicians are prone to misdiagnose. Finally, we review potential solutions, both educational and systemic, that may guard against the inevitable failings of the human mind, especially in a busy modern intensive care setting.