Aidan Burrell

Refractory cardiac arrest treated with mechanical CPR, hypothermia, ECMO and early reperfusion (the CHEER trial).

INTRODUCTION Many patients who suffer cardiac arrest do not respond to standard cardiopulmonary resuscitation. There is growing interest in utilizing veno-arterial extracorporeal membrane oxygenation assisted cardiopulmonary resuscitation (E-CPR) in the management of refractory cardiac arrest. We describe our preliminary experiences in establishing an E-CPR program for refractory cardiac arrest in Melbourne, Australia. METHODS The CHEER trial (mechanical CPR, Hypothermia, ECMO and Early Reperfusion) is a single center, prospective, observational study conducted at The Alfred Hospital. The CHEER protocol was developed for selected patients with refractory in-hospital and out-of-hospital cardiac arrest and involves mechanical CPR, rapid intravenous administration of 30 mL/kg of ice-cold saline to induce intra-arrest therapeutic hypothermia, percutaneous cannulation of the femoral artery and vein by two critical care physicians and commencement of veno-arterial ECMO. Subsequently, patients with suspected coronary artery occlusion are transferred to the cardiac catheterization laboratory for coronary angiography. Therapeutic hypothermia (33 °C) is maintained for 24h in the intensive care unit. RESULTS There were 26 patients eligible for the CHEER protocol (11 with OHCA, 15 with IHCA). The median age was 52 (IQR 38-60) years. ECMO was established in 24 (92%), with a median time from collapse until initiation of ECMO of 56 (IQR 40-85) min. Percutaneous coronary intervention was performed on 11 (42%) and pulmonary embolectomy on 1 patient. Return of spontaneous circulation was achieved in 25 (96%) patients. Median duration of ECMO support was 2 (IQR 1-5) days, with 13/24 (54%) of patients successfully weaned from ECMO support. Survival to hospital discharge with full neurological recovery (CPC score 1) occurred in 14/26 (54%) patients. CONCLUSIONS A protocol including E-CPR instituted by critical care physicians for refractory cardiac arrest which includes mechanical CPR, peri-arrest therapeutic hypothermia and ECMO is feasible and associated with a relatively high survival rate.

Predicting survival after ECMO for refractory cardiogenic shock: the survival after veno-arterial-ECMO (SAVE)-score

RATIONALE Extracorporeal membrane oxygenation (ECMO) may provide mechanical pulmonary and circulatory support for patients with cardiogenic shock refractory to conventional medical therapy. Prediction of survival in these patients may assist in management of these patients and comparison of results from different centers. AIMS To identify pre-ECMO factors which predict survival from refractory cardiogenic shock requiring ECMO and create the survival after veno-arterial-ECMO (SAVE)-score. METHODS AND RESULTS Patients with refractory cardiogenic shock treated with veno-arterial ECMO between January 2003 and December 2013 were extracted from the international Extracorporeal Life Support Organization registry. Multivariable logistic regression was performed using bootstrapping methodology with internal and external validation to identify factors independently associated with in-hospital survival. Of 3846 patients with cardiogenic shock treated with ECMO, 1601 (42%) patients were alive at hospital discharge. Chronic renal failure, longer duration of ventilation prior to ECMO initiation, pre-ECMO organ failures, pre-ECMO cardiac arrest, congenital heart disease, lower pulse pressure, and lower serum bicarbonate (HCO3) were risk factors associated with mortality. Younger age, lower weight, acute myocarditis, heart transplant, refractory ventricular tachycardia or fibrillation, higher diastolic blood pressure, and lower peak inspiratory pressure were protective. The SAVE-score (area under the receiver operating characteristics [ROC] curve [AUROC] 0.68 [95%CI 0.64-0.71]) was created. External validation of the SAVE-score in an Australian population of 161 patients showed excellent discrimination with AUROC = 0.90 (95%CI 0.85-0.95). CONCLUSIONS The SAVE-score may be a tool to predict survival for patients receiving ECMO for refractory cardiogenic shock (www.save-score.com).

Long-term survival of adults with cardiogenic shock after venoarterial extracorporeal membrane oxygenation.

PURPOSE This study was designed to examine the long-term survival of patients who survived to be weaned from venoarterial extracorporeal membrane oxygenation (VA ECMO) and to determine which factors present at initiation and during ECMO predict long-term survival. We further sought to develop the preliminary long-term outcome after VA ECMO score that would predict patient outcome and to assess its accuracy at various time points. METHODS We conducted a retrospective, observational cohort study of all patients with cardiogenic shock treated with VA ECMO at the Alfred Hospital, Australia, from January 2007 until February 2013. Overall, 125 patients underwent ECMO, and 104 patients were successfully weaned and formed the study population, with a median follow-up of 21 months (range, 0-84). RESULTS Survival rates of those weaned from ECMO at 3 months, 12 months, and 2 years were 87%, 79%, and 71%, respectively, corresponding to overall survival rates at 3 months of 90 (72%) of 124; at 12 months, 80 (65%) of 122; and 24 months, 57 (57%) of 100. Ischemic heart disease, higher lactate and higher bilirubin at initiation of VA ECMO, and a longer duration of renal replacement therapy during ECMO were all independently associated with decreased length of survival. Long-term survival was found to be highly related to the number of these risk factors present up to 2 years afterward. CONCLUSION Good long-term survival can be achieved in patients who have been successfully weaned from VA-ECMO. The factors present at initiation and during ECMO can relate to altered risk of long-term survival.

Right ventricular failure after implantation of continuous flow left ventricular assist device: analysis of predictors and outcomes

Postoperative right ventricular failure is a serious complication for up to 50% of patients following LVAD insertion. Predicting RV failure is an important factor for patients as planned BiVAD support has been shown to correlate with better outcomes compared to delayed BiVAD to LVAD conversion. This retrospective study examined prospectively collected data for 101 patients implanted with an LVAD between 2003 and 2013, aiming to establish preoperative predictive factors for RVF post‐LVAD insertion, analyze outcomes, and validate existing RVF scoring systems. In our cohort, 63 patients (62.4%) developed RV failure and consequently demonstrated consistently poorer survival throughout the follow‐up period (log‐rank p = 0.01). Multivariable logistic regression identified two significant variables: cardiac index <2.2 preoperatively despite inotropic support (OR 4.6 [95%CI 1.8–11.8]; p = 0.001) and preoperative tricuspid regurgitation (OR 8.1 [95%CI 1.9–34]; p = 0.004). Patients who developed RV failure had more complicated postoperative courses including longer ICU stay (p < 0.001), higher incidence of transfusions (p = 0.03) and re‐intubation (p = 0.001), longer ventilation duration (p < 0.001), and higher incidence of returning to theater (p = 0.0008). This study found that previous validation models had only moderate correlation with our population emphasizing the need for prospective validation of these scores in the current era of continuous flow devices.

Clinical utility of invasive exercise hemodynamic evaluation in LVAD patients

left ventricular assist devices. J Heart Lung Transplant 2010;29: 593-594. 2. Lanier GM, Orlanes K, Hayashi Y, et al. Validity and reliability of a novel slow cuff-deflation system for noninvasive blood pressure monitoring in patients with continuous-flow left ventricular assist device. Circ Heart Fail 2013;6:1005-12. 3. Woldendorp K, Gupta S, Lai J, et al. A novel method of blood pressure measurement in patients with continuous-flow left ventricular assist devices. J Heart Lung Transplant 2014;33:1183-6. 4. Feldman D, Pamboukian SV, Teuteberg JJ, et al. The 2013 International Society for Heart and Lung Transplantation guidelines for mechanical circulatory support: executive summary. J Heart Lung Transplant 2013;32:157-87.

Percutaneous cannulation in predominantly venoarterial extracorporeal membrane oxygenation by intensivists

Critical Care Medicine www.ccmjournal.org e595 The authors reply: The letter by Burrell et al (1) describing the percutaneous cannulation experience by intensivists at Alfred Hospital provides important information for intensivists involved in extracorporeal life support (ECLS) programs and nicely complements our reported experience (2). Our ECLS program has historically provided predominantly respiratory support, and our cardiac support experience is more limited. Our ECLS experience consists mostly of venovenous cannulation with a smaller venoarterial cohort. Burrell et al (1) describe their cannulation experience, which includes a large venoarterial cohort. Aspects of the Alfred Hospital experience deserve mention. The first is their success with arterial cannulation with a low complication rate. Arterial cannulation entails more inherent risk than venous because arterial injury can lead to substantial more morbidity than venous injury. The 8% arterial complication rate reported, although higher than their venous rate (2%), is not unexpected and would not be considered excessive. Some of their complications required surgical management, so the availability of surgical services would seem advisable. Another aspect is the larger number of intensivists (16) available to perform cannulations. Although this would seem to dilute the experience of each intensivist, the approach of having more than one intensivist cannulating a given patient (as we do) increases the exposure to the procedure and helps maintain cannulation skills. secured. A second patient’s internal jugular venous access cannula was accidentally dislodged and removed but was resecured without major consequence. Overall average ECMO duration was 4 ± 4 days for VA ECMO and 14 ± 4 days for VV ECMO. Survival to hospital discharge was 73 of 122 (60%) for VA ECMO (including extracorporeal CPR) and 32 of 45 (71%) for VV ECMO. In total, seven of 167 patients (4%) had hemorrhagic or ischemic stroke, and there was one blood stream infection, and one confirmed cannula related infection. In conclusion, intensivist-led cannulation is also possible for a predominantly VA ECMO service and is associated with an acceptable complication rate. The authors have disclosed that they do not have any potential conflicts of interest.

Modelling risk-adjusted variation in length of stay among Australian and New Zealand ICUs

Purpose Comparisons between institutions of intensive care unit (ICU) length of stay (LOS) are significantly confounded by individual patient characteristics, and currently there is a paucity of methods available to calculate risk-adjusted metrics. Methods We extracted de-identified data from the Australian and New Zealand Intensive Care Society (ANZICS) Adult Patient Database for admissions between January 1 2011 and December 31 2015. We used a mixed-effects log-normal regression model to predict LOS using patient and admission characteristics. We calculated a risk-adjusted LOS ratio (RALOSR) by dividing the geometric mean observed LOS by the exponent of the expected Ln-LOS for each site and year. The RALOSR is scaled such that values <1 indicate a LOS shorter than expected, while values >1 indicate a LOS longer than expected. Secondary mixed effects regression modelling was used to assess the stability of the estimate in units over time. Results During the study there were a total of 662,525 admissions to 168 units (median annual admissions = 767, IQR:426–1121). The mean observed LOS was 3.21 days (median = 1.79 IQR = 0.92–3.52) over the entire period, and declined on average 1.97 hours per year (95%CI:1.76–2.18) from 2011 to 2015. The RALOSR varied considerably between units, ranging from 0.35 to 2.34 indicating large differences after accounting for case-mix. Conclusions There are large disparities in risk-adjusted LOS among Australian and New Zealand ICUs which may reflect differences in resource utilization.

Impact of cardiac magnetic resonance imaging - cardiac contusion with intramural hemorrhage –

Received June 3, 2014; revised manuscript received August 20, 2014; accepted September 1, 2014; released online October 2, 2014 Time for primary review: 28 days Department of Cardiovascular Medicine (A.J.C.B., J.L.H., P.J.F., D.M.K., A.J.T.), Department of Trauma (M.F.), Intensive Care Unit (A.J.C.B., D.J.C., D.M.), Alfred Hospital, Melbourne, Victoria; Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria (A.J.C.B., D.J.C., D.M.); and Baker IDI Heart and Diabetes Institute, Melbourne, Victoria (J.L.H., D.M.K., A.J.T.), Australia Mailing address: Aidan J.C. Burrell, MD, Department of Cardiovascular Medicine, Alfred Hospital, 55 Commercial Road, Melbourne, Vic. 3181, Australia. E-mail: aidan.burrell@monash.edu ISSN-1346-9843 doi: 10.1253/circj.CJ-14-0626 All rights are reserved to the Japanese Circulation Society. For permissions, please e-mail: cj@j-circ.or.jp Impact of Cardiac Magnetic Resonance Imaging – Cardiac Contusion With Intramural Hemorrhage –

ICU Admissions for Sepsis or Pneumonia in Australia and New Zealand in 2017

Influenza and Admissions to Intensive Care Units Each year, influenza causes a variable burden of illness. During the late winter and early spring of 2017, influenza infection was associated with a...

Complications of mechanical circulatory and respiratory support

Abstract Despite the benefits of mechanical circulatory and respiratory support (MCS), patients undergoing extracorporeal membrane oxygenation (ECMO) and the implantation of ventricular assist devices (VADs) continue to experience high rates of serious and life-threatening complications. These include bleeding, thrombosis, sepsis, multiorgan dysfunction, and death. These complications may be caused by the mechanical support or the underlying critical illness that necessitates its use. Reducing MCS complications remains an important goal for the future uptake of this technology.