Continuous monitoring of membrane lung carbon dioxide removal during ECMO: experimental testing of a new volumetric capnometer.

BACKGROUND: Extracorporeal membrane oxygenation constitutes a complex support modality, and accurate monitoring is required. An ideal monitoring system should promptly detect ECMO malfunctions and provide real-time information to optimize the patient-machine interactions. We tested a new volumetric capnometer which enables continuous monitoring of membrane lung carbon dioxide removal (V'CO2ML), to help in estimating the oxygenator performance, in terms of CO2 removal and oxygenator dead space (VDsML). METHODS: This study was conducted on nine pigs undergoing veno-arterial ECMO due to cardiogenic shock after induced acute myocardial infarction. The accuracy and reliability of the prototype of the volumetric capnometer (CO2RESET™, by Eurosets srl, Medolla, Italy) device was evaluated for V'CO2ML and VDsML measurements by comparing the obtained measurements from the new device to a control capnometer with the sweep gas values. Measurements were taken at five different levels of gas flow/blood flow ratio (0.5-1.5). Agreement between the corresponding measurements was taken with the two methods. We expected that 95% of differences were between d - 1.96s and d + 1.96s. RESULTS: In all, 120 coupled measurements from each device were obtained for the V'CO2ML calculation and 40 for the VDsML. The new capnometer mean percentage bias (95% confidence interval limits of agreement) was 3.86% (12.07-4.35%) for V'CO2ML and 2.62% (8.96-14.20%) for VDsML. A negative proportional bias for V'CO2ML estimation with the new device was observed with a mean of 3.86% (12.07-4.35%). No correlations were found between differences in the coupled V'CO2ML and VDsML measurements and the gas flow/blood flow ratio or temperature. Coupled measurements for V'CO2ML showed strong correlation (rs = 0.991; p = 0.0005), as did VDsML calculations (rs = 0.973; p = 0.0005). CONCLUSION: The volumetric capnometer is reliable for continuous monitoring of CO2 removal by membrane lung and VDsML calculations. Further studies are necessary to confirm these data.

In-hospital outcome of post-cardiotomy extracorporeal life support in adult patients: the 2007-2017 Maastricht experience.

OBJECTIVES: The use of post-cardiotomy extracorporeal life support (PC-ECLS) has increased worldwide over the past years but a concurrent decrease in survival to hospital discharge has also been observed. We analysed use and outcome of PC-ECLS at the Maastricht University Medical Center. DESIGN: A retrospective study of a single-centre PC-ECLS cohort. Patient characteristics and in-hospital outcomes were evaluated. SETTING: Patients who underwent PC-ECLS due to intra- or peri-operative cardiogenic shock or cardiac arrest were included. Descriptive statistics were analysed and frequency analysis and testing of group differences were performed. PARTICIPANTS: Eighty-six patients who received PC-ECLS between October 2007 and June 2017 were included. The mean age of the population was 65 years (range, 31-86 years), and 65% were men. MAIN OUTCOME MEASURES: Survival rates were calculated and PC-ECLS management data and complications were assessed. RESULTS: Pre-ECLS procedures were isolated coronary artery bypass grafting (CABG) (22%), isolated valve surgery (16%), thoracic aorta surgery (4%), a combination of CABG and valve surgery (21%) or other surgery (24%). PC-ECLS was achieved via central cannulation in 17%, peripheral cannulation in 65%, or by a combination in 17%. The median duration of PC-ECLS was 5.0 days (IQR, 6.0 days). Weaning was achieved in 49% of patients, and 37% survived to discharge. Post-operative bleeding (overall rate, 42%) showed a trend towards a reduced rate over more recent years. CONCLUSIONS: Our experience confirms an increased use of PC-ECLS during the last 10 years and shows that, by carefully addressing patient management and complications, survival rat e may be satisfactory, and improved outcome may be achieved in such a challenging ECLS setting.

Modalities and Effects of Left Ventricle Unloading on Extracorporeal Life support: a Review of the Current Literature.

INTRODUCTION/AIM: Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) support is increasingly used in refractory cardiogenic shock and cardiac arrest, but is characterized by a rise in afterload of the left ventricle (LV) which may ultimately either further impair or delay cardiac contractility improvement. The aim of this study was to provide a comprehensive overview regarding the different LV venting techniques and results currently available in the literature. METHODS: A systematic literature search was performed in the PubMed database: 207 articles published between 1993 and 2016 were included. Papers dealing with pre-clinical studies, overlapping series, and association with other assist devices were excluded from the review, with 45 published papers finally selected. Heterogeneous indications for LV unloading were reported. The selected literature was divided into subgroups, according to the location or the performed procedure for LV venting. RESULTS: Case reports or case series accounted for 60% of the papers, while retrospective study represented 29% of them. Adult series were present in 67%, paediatric patients in 29%, and a mixed population in 4%. LV unloading was performed percutaneously in 84% of the cases. The most common locations of unloading was the left atrium (31%), followed by indirect unloading (intra-aortic balloon pump) (27%), trans-aortic (27%), LV (11%), and pulmonary artery (4%). Percutaneous trans-septal approach was reported in 22%. Finally, the unloading was conducted surgically in 16%,with open chest surgery in 71%, and minimally invasive surgery in 29% of surgical cases. CONCLUSION: Nowadays, only a few data are available about left heart unloading in V-A ECMO support. Despite the well-known controversy, IABP remains widely used in combination with V-A ECMO. Percutaneous approaches utilizing unloading devices is becoming an increasingly used option. However, further studies are required to establish the optimal LV unloading method.

[Results and complications of permanent pacing in pediatric patients with congenital or acquired atrioventricular block]. / Risultati e complicanze dell'impianto di pacemaker definitivo in pazienti pediatrici con blocco atrioventricolare congenito ed acquisito.

BACKGROUND: Currently there is no evidence to prefer an endocardial or epicardial approach for pacing in pediatric patients. This analysis was aimed at defining the complications of pacemaker implantation in a pediatric population with atrioventricular block according to a strategy of choosing an epicardial system for patients <10 kg and an endocardial system for patients >10 kg. METHODS: This is a retrospective study performed on 27 patients, with and without congenital heart disease, implanted with a permanent pacemaker because of idiopathic or acquired atrioventricular block at our Pediatric Cardiology and Cardiac Surgery Unit of S. Orsola-Malpighi Hospital in Bologna (Italy) between 1981 and 2010. Patients were divided into two groups: 70% of the population (group A) was implanted with an epicardial system, 30% (group B) with an endocardial system. RESULTS: After a mean follow-up of 14 years (17 ± 8 years for group A, 7 ± 5 years for group B), the most frequent complications were lead failure (44%) and infection (18%). Both were more common in the epicardial system group: lead failure rate 53% in group A vs 25% in group B (p=0.0001); infection rate 26% in group A vs 0% in group B (p=0.0001); rate of system revision or implantation of a new electrode 42% in group A vs 12% in group B (p=0.0001). CONCLUSIONS: The present study demonstrates a high complication rate in patients undergoing an epicardial pacing system implantation. However, in patients <10 kg the epicardial system allows subclavian venous access protection for endocardial system implantation after somatic growth, avoiding high-risk procedures of system revision or lead extraction and subclavian vein occlusion in the long term.