Leonello Avalli

Volume/pressure curve of total respiratory system in paralysed patients: artefacts and correction factors

The volume/pressure (V/P) curve of the total respiratory system in paralysed patients is drawn assuming that volume changes of the respiratory system (ΔV resp) equals volume displacement of the measuring apparatus (ΔV syr), usually a supersyringe. However, in 93 VP curves we found that O2 removed from the lung-syringe system during the procedure (proportional to the time) largely exceedes the CO2 added to the lung-syringe system (ΔV gas). This results in a net loss of volume from the system (ΔV resp<ΔV-syr). Deflation compliance, hysteresis area and ratio are significantly affected by this phenomenon. Inflation compliance is less influenced by ΔV gas, partially compensated by the intrapulmonary gas expansion due to the temperature changes. We conclude that the parameters computed on the deflation limb of V/P curve are misleading if proper correction of the volume scale is not introduced.

Favourable survival of in-hospital compared to out-of-hospital refractory cardiac arrest patients treated with extracorporeal membrane oxygenation: An Italian tertiary care centre experience

OBJECTIVE Extracorporeal membrane oxygenation (ECMO) support has been suggested to improve the survival rate in patients with refractory in- and out-of-hospital cardiac arrest (IHCA and OHCA). The aim of our study is to report our experience with ECMO in these patients. DESIGN Retrospective, single-centre, observational study. PATIENTS From January 2006 to February 2011 we studied 42 patients (31 males) with refractory cardiac arrest. MEASUREMENT AND MAIN RESULTS ECMO implantation was successful in 38 (90%) of the 42 patients. ECMO support was positioned: three times (8%) in the operating room, six (16%) in the cardiac surgery intensive care unit, 21 (55%) in the emergency room, five (13%) in the catheterisation laboratory and three (8%) in the general ward. A total of 14 IHCA (58%) and three OHCA (16%) patients were weaned from ECMO (p<0.05). Eleven IHCA (46%) and one OHCA (5%, p<0.05) patients were discharged from intensive care unit (ICU). Among IHCA patients, 10 were alive at 6 months, nine of whom (38%) with good neurological outcome. Among OHCA patients weaned from ECMO, one was alive at 6 months with good neurological outcome (5%, p<0.05 vs. IHCA). CONCLUSIONS ECMO support should be considered as a resuscitation alternative in selected patients. More specifically, patients with witnessed IHCA benefit more from ECMO treatment compared to those who experience an out-of-hospital cardiac arrest.

Percutaneous left-heart decompression during extracorporeal membrane oxygenation: an alternative to surgical and transeptal venting in adult patients.

Extracorporeal membrane oxygenation (ECMO) is often applied for acute cardiorespiratory failure. Left ventricular distension can compromise recovery of the failing heart. To overcome this complication, we describe a new technique to decompress the left heart through the insertion of a venting cannula in the pulmonary artery. A 43-year-old woman was connected to ECMO for refractory cardiogenic shock after left pneumonia and severe sepsis. Transesophageal echocardiography (TEE) revealed a large intraventricular clot. A 15F venous cannula was placed percutaneously in the pulmonary artery and connected to the venous limb of the ECMO circuit to decompress the left heart, and to prevent left ventricular ejection and potential embolization. After myocardial recovery, when the thrombus was judged as stable, the patient was weaned, and ECMO was removed on day 16. The patient was discharged from the cardiac surgery intensive care unit on day 30 and subsequently had an uneventful recovery. This new percutaneous approach represent a feasible and effective method to vent the left heart during ECMO, when it becomes necessary to reduce wall tension or to prevent ejection.

Extracorporeal membrane oxygenation to support adult patients with cardiac failure: predictive factors of 30-day mortality

Adult patients supported on extracorporeal membrane oxygenation (ECMO) are very sick and many complications are often present in each single patient; therefore, it is not always easy to find some risk factors that can predict the early outcome. This retrospective study reports our experience in ECMO support treatment in adult cardiac patients suffering from cardiac failure (CF) in which one or more predictive factors of 30-day mortality were analyzed. Between January 2002 and August 2009, 42 consecutive adult cardiac patients with cardiogenic shock (mean age 64.3+/-11.3 years) were supported on ECMO for >2 days. They were divided into patients who had a survival <30 days (n=20) and patients who survived >30 days (n=22). Twenty-nine patients (69%) survived on ECMO. Sixteen patients were discharged with a survival rate of 38.1%. The overall mean ECMO duration was 7.9+/-5.3 days. The following variables were significantly different between the two groups: number of platelets and packed red blood cells (PRBCs) transfused per day during ECMO (P=0.002 and P=0.003), blood lactate levels 48 h and 72 h after the initiation of ECMO (P=0.01 and P=0.04), indexed blood flow after 48 h and 72 h (P=0.01 and P<0.0001), liver failure (P=0.001) and multiorgan failure (P=0.002). Stepwise logistic regression identified that blood lactate levels at 48 h and number of PRBCs transfused were associated with 30-day mortality [P=0.019, odds ratio (OR) =2.16; 95% confidence interval (CI)=1.13-4.14 and P=0.008, OR=1.08; 95% CI=1.02-1.14, respectively]. The predicted probability of mortality would be 52% when blood lactate levels are >3 mmol/l after 48 h. The blood lactate level at 48 h and PRBCs transfused per day can be considered as important parameters to predict the mortality in adult cardiac patients supported by ECMO for CF.

Extracorporeal membrane oxygenation with a poly-methylpentene oxygenator (Quadrox D). The experience of a single Italian centre in adult patients with refractory cardiogenic shock.

Although microporous polypropylene hollow fiber oxygenators are standard devices used for extracorporeal membrane oxygenation (ECMO), they have limitations such as development of plasma leakage. Poly-methylpentene (PMP) is a new material used for the last generation of oxygenators. We reviewed our experience with a new PMP oxygenator (Quadrox D) and a centrifugal pump (RotaFlow) used to support adult patients with refractory cardiogenic shock. Between January 2000 and April 2007, 25 patients required ECMO for primary or postcardiotomy cardiogenic shock. Eighteen patients were analyzed [mean age 60.2 years; 11 (61%) men; 7 (39%) women]. Nine patients (50%) suffered primary cardiogenic shock. Cardiopulmonary resuscitation was applied in 11 patients (61%) with a mean duration time of 31.5 minutes. Mean ECMO duration time was 7.1 ± 6.3 days (range, 1–27 days). Intra-aortic balloon pump was used in 13 patients (72.2%) with a mean duration time of 7.7 ± 5 (range, 2–17 days). Twelve patients (66.7%) survived on ECMO and five patients (27.8%) were discharged. Our results indicate the PMP oxygenator and the centrifugal pump provided acceptable results in terms of surviving on ECMO and discharge. Patients with an initial catastrophic hemodynamic status could benefit by means of a rapid institution of ECMO with PMP oxygenators.

Myocardial revascularization with miniaturized extracorporeal circulation versus off pump: Evaluation of systemic and myocardial inflammatory response in a prospective randomized study.

OBJECTIVE This prospective randomized study sought to verify the systemic inflammatory response, inflammatory myocardial damage, and early clinical outcome in coronary surgery with the miniaturized extracorporeal circulation system or on the beating heart. METHODS Sixty consecutive patients were randomized to miniaturized extracorporeal circulation (n = 30) or off-pump coronary revascularization (off-pump coronary artery bypass grafting, n = 30). Intraoperative and postoperative data were recorded. Plasma levels of interleukin-6 and tumor necrosis factor-alpha were measured from systemic blood intraoperatively, at the end of operation, and 24 and 48 hours thereafter. Levels of the same markers and blood lactate were measured from coronary sinus blood intraoperatively to evaluate myocardial inflammation. Markers of myocardial damage were also analyzed. RESULTS One patient died in the off-pump coronary artery bypass grafting group. There was no statistical difference in early clinical outcome in both groups. Release of interleukin-6 was higher in the off-pump coronary artery bypass grafting group 24 hours after the operation (P = .03), whereas levels of tumor necrosis factor-alpha were not different in both groups. Cardiac release of interleukin-6, tumor necrosis factor-alpha, and blood lactate were not different in both groups. Release of troponin T was not significantly different in both groups. Levels of creatine kinase mass were statistically higher in the miniaturized extracorporeal circulation group than in the off-pump coronary artery bypass grafting group, but only at the end of the operation (P < .0001). Hemoglobin levels were significantly higher in the miniaturized extracorporeal circulation group than in the off-pump coronary artery bypass grafting group after 24 hours (P = .01). CONCLUSION Miniaturized extracorporeal circulation can be considered similar to off-pump surgery in terms of systemic inflammatory response, myocardial inflammation and damage, and early outcome.

New treatment bundles improve survival in out-of-hospital cardiac arrest patients: a historical comparison.

INTRODUCTION Before the introduction of the new international cardiac arrest treatment guidelines in 2005, patients with out-of-hospital cardiac arrest (OHCA) of cardiac origin in Northern Italy had very poor prognosis. Since 2006, a new bundle of care comprising use of automated external defibrillators (AEDs) and therapeutic hypothermia (TH) was started, while extracorporeal CPR program (ECPR) for selected refractory CA and dispatcher-assisted cardio-pulmonary resuscitation (CPR) was started in January 2010. OBJECTIVES We hypothesized that a program of bundled care might improve outcome of OHCA patients. METHODS We analyzed data collected in the OHCA registry of the MB area between September 2007 and August 2011 and compared this with data from 2000 to 2003. RESULTS Between 2007 and 2011, 1128 OHCAs occurred in the MB area, 745 received CPR and 461 of these had a CA of presumed cardiac origin. Of these, 125 (27%) achieved sustained ROSC, 60 (13%) survived to 1 month, of whom 51 (11%) were discharged from hospital with a good neurological outcome (CPC≤2), and 9 with a poor neurological outcome (CPC>2). Compared with data from the 2000 to 2003 periods, survival increased from 5.6% to 13.01% (p<0.0001). In the 2007-2011 group, low-flow time and bystander CPR were independent markers of survival. CONCLUSIONS OHCA survival has improved in our region. An increased bystander CPR rate associated with dispatcher-assisted CPR was the most significant cause of increased survival, but duration of CA remains critical for patient outcome.

Post-cardiac arrest extracorporeal life support

Sudden cardiac arrest is a complex, life-threatening event involving a multidisciplinary approach. Despite the use of conventional cardiopulmonary resuscitation, survival rate continues to be low for both in-hospital and out-of-hospital cardiac arrest. In refractory cardiac arrest, defined by the absence of return of spontaneous circulation despite resuscitation manoeuvres, mortality approaches 100%. In the last years, an increasing number of case series, and few propensity-matched cohort studies have reported encouraging results on the use of venoarterial extracorporeal membrane oxygenation for refractory cardiac arrest. Extracorporeal circulation ensures an adequate blood flow, to perform diagnostic and therapeutic interventions even before a return of spontaneous circulation is achieved and to rest the heart by unloading the ventricle while ensuring myocardial perfusion after return of spontaneous circulation. This study reviews the rational, indications, evidence and management of extracorporeal support for cardiac arrest.

Organ donation in cardiac arrest patients treated with extracorporeal CPR: A single centre observational study

AIM OF THE STUDY In a consecutive cohort of cardiac arrest (CA) treated with extracorporeal cardiopulmonary resuscitation (eCPR), we describe the incidence of brain death (BD), the eligibility for organ donation and the short-term follow-up of the transplanted organs. METHODS All refractory in- and out-of-hospital CA admitted to our Cardiac Intensive Care Unit between January 2011 and September 2016 treated with eCPR were enrolled in the study. RESULTS 112 CA patients received eCPR. 82 (73.2%) died in hospital, 25 BD (22.3%) and 57 for other causes (50.9%). At the time of first neurological evaluation after rewarming, variables related to evolution to BD were a lower GCS (3 [3-3] vs. 8 [3-11], p<0.001), a higher level of neuron specific enolase (269.3±49.4 vs. 55.2±37.2ng/ml, p<0.001), a higher presence of EEG indices of poor outcome (84% vs. 15%, p<0.001), absence of brainstem reflexes (p<0.001), absence of bilateral N20 SSEPS waves (66.7% vs. 3.7%, p<0.001). None of BD patients present a normal CT scan (at 2.5±2days), with 85% prevalence of diffuse hypoxic injury and a mean grey/white matter ratio of 1.1±0.1. Rate of donation in BD patients was 56%, with 39 donated organs: 23 kidneys, 12 livers, and 4 lungs. 89.74% of the transplanted organs reached an early good functional recovery. CONCLUSION In refractory CA patients treated with eCPR, the prevalence of BD is high. This population has a high potential for considering organ donation. Donated organs have a good outcome.

Assessing Endothelial Responsiveness After Cardiopulmonary Bypass: Insights on Different Perfusion Modalities

OBJECTIVE Cardiopulmonary bypass (CPB) exerts several deleterious effects on inflammatory pathways. Most of these can be related to an endothelial insult leading to endothelial dysfunction. To date, the degree of endothelial damage only has been evaluated on a cellular and molecular level, but no studies exist looking at the functional effects of CPB on the endothelium. DESIGN Previous studies hypothesized a negative effect of continuous flow as opposed to the physiologic pulsatile flow. The aim of the present retrospective study was to investigate how different perfusion modalities during CPB (ie, continuous v pulsatile flow) or its avoidance differently impact endothelial function. SETTING Cardiovascular operating room and intensive care unit of a large tertiary University Hospital in Monza, Italy. PARTICIPANTS Flow-mediated dilatation (FMD) of the brachial artery was assessed in 29 patients undergoing elective myocardial revascularization. Ten patients receiving continuous-flow CPB, 10 receiving pulsatile-flow CPB, and 9 scheduled for beating-heart revascularization were studied. INTERVENTIONS Patients were studied at baseline (after induction of general anesthesia), after CPB upon intensive care unit (ICU) admission after surgery, and on the first postoperative day before discharge from the ICU (on average, 24 hours after CPB discontinuation). MEASUREMENTS AND MAIN RESULTS The continuous-flow CPB group demonstrated a significant reduction in FMD after CPB, (12.8% ± 9.7% v 1.6% ± 1.5%, p<0.01), which lasted up to the first postoperative day (5.9% ± 4.1%). On the other hand, FMD did not change in the pulsatile-flow group (12.5% ± 10.5%, 11.0% ± 7.2%, and 16.6% ± 11.7%, respectively). FMD also was unaffected in the beating-heart group, thus suggesting a direct effect of CPB itself on endothelial function. CONCLUSIONS In conclusion, in this study population of adult patients undergoing elective coronary revascularization, continuous-flow CPB markedly impaired endothelial function, although this was not the case with pulsatile-flow CPB. This study posed the rationale for further investigations on the potential value of FMD to predict cardiovascular events in these patients.