Advanced Critical Care Techniques in the Field

Critical care principles and techniques continue to hold promise for improving patient outcomes in time-dependent diseases encountered by emergency medical services such as cardiac arrest, acute ischemic stroke, and hemorrhagic shock. In this review, the authors discuss several current and evolving advanced critical care modalities, including extracorporeal cardiopulmonary resuscitation, resuscitative endovascular occlusion of the aorta, prehospital thrombolytics for acute ischemic stroke, and low-titer group O whole blood for trauma patients. Two important critical care monitoring technologies-capnography and ultrasound-are also briefly discussed.

Outcome of patients supported with the HeartMate 3 after extracorporeal life support: On behalf of the Durable Mechanical Circulatory Support After Extracorporeal Life Support Study Group

OBJECTIVES

The Durable Mechanical Circulatory Support System After Extracorporeal Life Support registry is a multicenter registry of patients who were bridged from extracorporeal life support to a durable mechanical circulatory support system. Although numerous studies have highlighted the favorable outcomes after implantation of the HeartMate 3 (Abbott), the objective of our study is to examine the outcomes of patients who received HeartMate 3 support after extracorporeal life support.

METHODS

Data of patients undergoing HeartMate 3 implantation from January 2016 to April 2022 at 14 centers were collected and evaluated. Inclusion criteria were patients with extracorporeal life support before HeartMate 3 implantation. The outcome was reported and compared with patients receiving other types of pumps.

RESULTS

A total of 337 patients were bridged to durable mechanical circulatory support system after extracorporeal life support in the study period. Of those patients, 140 were supported with the HeartMate 3. The other types of pumps included 170 HeartWare HVADs (Medtronic) (86%), 14 HeartMate II devices (7%), and 13 (7%) other pumps (7%). Major postoperative complications included right heart failure requiring temporary right ventricular assist device in 60 patients (47%). Significantly lower postoperative stroke (16% vs 28%, P = .01) and pump thrombosis (3% vs 8%, P = .02) rates were observed in the patients receiving the HeartMate 3. The 30-day, 1-year, and 3-year survivals in patients receiving the HeartMate 3 were 87%, 73%, and 65%, respectively.

CONCLUSIONS

In this critically ill patient population, the survivals of patients who were transitioned to the HeartMate 3 are deemed acceptable and superior to those observed when extracorporeal life support was bridged to other types of durable mechanical circulatory support systems.

Advanced Nanocomposite Hydrogels for Cartilage Tissue Engineering

Tissue engineering is becoming an effective strategy for repairing cartilage damage. Synthesized nanocomposite hydrogels mimic the structure of natural cartilage extracellular matrices (ECMs), are biocompatible, and exhibit nano–bio effects in response to external stimuli. These inherent characteristics make nanocomposite hydrogels promising scaffold materials for cartilage tissue engineering. This review summarizes the advances made in the field of nanocomposite hydrogels for artificial cartilage. We discuss, in detail, their preparation methods and scope of application. The challenges involved for the application of hydrogel nanocomposites for cartilage repair are also highlighted.

Rescue extracorporeal life support as a bridge to durable left ventricular assist device

BACKGROUND

The ideal timing of a durable assist device implantation in patients with end-stage heart failure presenting with INTERMACS profile I is still controversial. The data on extracorporeal life support (ECLS) bridge to durable left ventricular assist device (LVAD) in these patients is limited.

MATERIALS AND METHODS

We retrospectively analyzed the outcomes of 35 patients in acute cardiogenic shock (CS) who, between December 2013 and September 2020, were bridged with ECLS to durable LVAD. The mean age was 52.3 ± 12.0 years. The primary endpoints of this study were in-hospital, 30-day, 6-month, and 1-year mortality. The secondary endpoint was the development of any postoperative adverse events and other characteristics during the follow-up period. We also assessed the impact of the rescue ECLS on the recovery of the end-organ function.

RESULTS

In-hospital, 30-day, 6-month, and 1-year survival was 65.6%, 75.9%, 69.2%, and 62.7% respectively. The median time on ECLS was 7 days (IQR 5.0-13.0). We observed a high incidence of a severe right heart failure (22.9%), acute kidney injury on dialysis (68.6%), and respiratory failure (77.1%). Bridge with ECLS provided a significant recovery of liver and kidney function prior to durable LVAD implantation.

CONCLUSION

The concept of bridging patients presenting in end-stage heart failure and cardiogenic shock with ECLS prior to durable LVAD implantation is a feasible method to ensure acceptable survival rates and significant recovery of the end-organ function.

Minimally invasive ventricular assist device implantation

Durable mechanical circulatory support (MCS) systems are established therapy option in patients with end-stage heart failure, with increasing importance during the last years due to donor organ shortage. Left ventricular assist devices (LVADs) are traditionally implanted through median sternotomy (MS). However, improvement in the pump designs during the last years led to evolvement of new surgical approaches that aim to reduce the invasiveness of the procedure. Numerous reports and studies have shown the viability and possible advantages of less-invasive approach compared to the sternotomy approach. The less invasive implant strategies for LVADs, while vague in definition, are characterized by minimizing surgical trauma and if possible, cardio-pulmonary bypass related complications. Usually it involves minimizing or completely avoiding sternal trauma, avoiding heart luxation while simultaneously leaving the major part of pericardium intact. There is no consensus between the centers regarding the ideal approach for LVAD implantation. Some centers, like our center, perform by default VAD implantation using less invasive approach in almost all patients and some centers use only sternotomy approach. The aim of this review article is to shed light on the currently available less invasive options of LVAD implantation, with particular focus on the centrifugal pumps, and their possible advantages compared to traditional sternotomy approach.

Outcomes of VA-ECMO with and without Left Centricular (LV) Decompression Using Intra-Aortic Balloon Pumping (IABP) versus Other LV Decompression Techniques: A Systematic Review and Meta-Analysis

Background

Left ventricular decompression is the primary method for solving VA-ECMO-induced LV afterload increase, but the effect of specific methods on patient outcomes and complications is unknown.

Material/Methods

We searched for all published reports conducted in patients undergoing ECMO combined with LVD. Statistical analyses were performed using Stata 12.0.

Results

The results showed that the risk of death with ECMO combined with LVD was 29% lower than that with ECMO alone (OR=0.71, 95% CI: 0.56–0.89, I²=59.5%, P<0.001). Although the risk of death with ECMO combined other LV decompression techniques was higher than that with ECMO combined with IABP, the difference was not statistically significant (OR=1.27, 95% CI: 0.86–1.87, I²=44.0%, P=0.057). In addition, the ORs values of hemorrhage, stroke/acute episodes, lower-limb ischemia, and hemolysis for ECMO combined with LVD were 0.69 (0.66–0.71), 0.82 (0.78–0.89), 0.71 (0.30–1.66), and 0.48 (0.16–1.39), respectively. The risk of complications, such as stroke/TIA, limb ischemia, and hemolysis, of ECMO combined with IABP was lower than that of ECMO combined other LV decompression techniques, and the risk of bleeding was higher for ECMO combined with IABP.

Conclusions

ECMO combined with LVD is more beneficial than using ECMO alone and helps to lower patient mortality.

Veno-Arterial Extracorporeal Membrane Oxygenation for Cardiogenic Shock

Extracorporeal membrane oxygenation has evolved, from a therapy that was selectively applied in the pediatric population in tertiary centers, to more widespread use in diverse forms of cardiopulmonary failure in all ages. We provide a practical review for cardiovascular clinicians on the application of veno-arterial extracorporeal membrane oxygenation in adult patients with cardiogenic shock, including epidemiology of cardiogenic shock, indications, contraindications, and the extracorporeal membrane oxygenation circuit. We also summarize cannulation techniques, practical management and troubleshooting, prognosis, and weaning and exit strategies, with attention to end of life and ethical considerations.

Impact of preoperative extracorporeal life support on left ventricular assist device outcomes: A comparative study

Background:

To investigate whether preoperative short-term extracorporeal life support therapy in patients undergoing continuous-flow left ventricular assist device implantation has an impact on the outcome regarding survival and adverse events.

Methods:

Between January 2011 and May 2018, 100 consecutive patients received HeartMate II, HeartWare, or HeartMate III for end-stage heart failure. Mean age was 64.2 ± 10.3 years. Three patient groups were identified: without preoperative extracorporeal life support (non-extracorporeal life support group, n = 80), with preoperative extracorporeal life support due to postcardiotomy shock after conventional cardiac surgery (postcardiotomy shock group, n = 9), and with preoperative extracorporeal life support without previous surgery (non-postcardiotomy shock group, n = 11). The primary endpoint was overall survival after device implantation. Secondary endpoints were adverse events during the follow-up period.

Results:

Survival was significantly different between the groups (p < 0.05): 30-day, 6-month, and 1-year survival rates were 85%, 68%, and 61% for non-extracorporeal life support group; 44%, 22%, and 22% for postcardiotomy shock group; and 45%, 27%, and 24% for non-postcardiotomy shock group, respectively. Furthermore, in both extracorporeal life support groups (postcardiotomy shock and non-postcardiotomy shock), there were a higher incidence (p < 0.05) of postoperative right heart failure (30% vs 66.7% vs 54.5%), acute renal failure requiring dialysis (20% vs 77.8% vs 54.5%), and respiratory failure (31.3% vs 88.9% vs 81.8%).

Conclusion:

Continuous-flow left ventricular assist device implantation with prior extracorporeal life support appears to have a worse outcome regarding survival, right heart failure, renal and respiratory dysfunction (p < 0.05). Future studies have to be done to evaluate the outcome after extracorporeal life support bridge pre-left ventricular assist device, especially as ultima ratio in postcardiotomy shock patients.

Traditional and non-traditional anticoagulation management during extracorporeal membrane oxygenation

Unfractionated heparin (UFH) is the anticoagulant of choice during extracorporeal membrane oxygenation (ECMO) support. Despite its favorable pharmacologic properties, management of heparin anticoagulation during ECMO remains a major challenge. To date, little is known about the optimal monitoring strategy or the heparin dose offering the best safety/efficacy profile. Therefore, it remains unclear if the heparin dose should be adapted to target a specific "clotting time" [e.g., activated clotting time (ACT) or activated partial thromboplastin time (aPTT)] or a heparin concentration, measured by coagulation factor anti-Xa assay. In addition, no study has compared the relevance of modern viscoelastic coagulation tests over the single value of a clotting time or heparin concentration value. Although guidelines for anticoagulation during ECMO support have been published, the absence of evidence limits the quality of the recommendations provided, which explains the major intra- and inter-institutional variability observed. Large prospective multicenter trials are urgently needed to investigate the optimal anticoagulation management strategy during ECMO support.

Treatment of chronic heart failure in the 21st century: A new era of biomedical engineering has come

Chronic heart failure (CHF) is a challenging burden on public health. Therapeutic strategies for CHF have developed rapidly in the past decades from conventional medical therapy, which mainly includes administration of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, and aldosterone antagonists, to biomedical engineering methods, which include interventional engineering, such as percutaneous balloon mitral valvotomy, percutaneous coronary intervention, catheter ablation, biventricular pacing or cardiac resynchronization therapy (CRT) and CRT-defibrillator use, and implantable cardioverter defibrillator use; mechanical engineering, such as left ventricular assistant device use, internal artery balloon counterpulsation, cardiac support device use, and total artificial heart implantation; surgical engineering, such as coronary artery bypass graft, valve replacement or repair of rheumatic or congenital heart diseases, and heart transplantation (HT); regenerate engineering, which includes gene therapy, stem cell transplantation, and tissue engineering; and rehabilitating engineering, which includes exercise training, low-salt diet, nursing, psychological interventions, health education, and external counterpulsation/enhanced external counterpulsation in the outpatient department. These biomedical engineering therapies have greatly improved the symptoms of CHF and life expectancy. To date, pharmacotherapy, which is based on evidence-based medicine, large-scale, multi-center, randomized controlled clinical trials, is still a major treatment option for CHF; the current interventional and mechanical device engineering treatment for advanced CHF is not enough owing to its individual status. In place of HT or the use of a total artificial heart, stem cell technology and gene therapy in regenerate engineering for CHF are very promising. However, each therapy has its advantages and disadvantages, and it is currently possible to select better therapeutic strategies for patients with CHF according to cost-efficacy analyses of these therapies. Taken together, we think that a new era of biomedical engineering for CHF has begun.

Establishing and Sustaining an ECPR Program

The use of extracorporeal support after failed return of a spontaneous ciruculation during cardiopulmonary resuscitation (ECPR) is well described. There are 4 distinct phases for resuscitation with ECPR and the time spent in each phase is critical for successful outcome. Recommendations for ECPR previously published by the American Heart Association provide the context for implementing a consistent and well-rehearsed system for ECPR, by people with the knowledge, experience and resources to deploy ECPR in the most optimal time frame possible in selected patient populations. In this manuscript we review the current status of ECPR for acute cardiac failure and the components we believe are necessary to develop and sustain a reliable and resilient program.

Extracorporeal life support prior to left ventricular assist device implantation leads to improvement of the patients INTERMACS levels and outcome

Background

The objective of this study was to evaluate the outcome of left ventricular assist device (LVAD) implantation after initial extracorporeal life support (ECLS) in patients with cardiogenic shock and the incidence of post implantation right ventricular failure.

Methods & results

All patients on ECLS therapy for cardiogenic shock prior to LVAD implantation (n = 15) between October 2011 and January 2014 were analyzed. Baseline patient characteristics, as well as detailed pre-operative treatment and postoperative outcome data were collected retrospectively. At time of admission to our unit all patients were classified INTERMACS II or higher (12 [80%] INTERMACS I). Improvement to INTERMACS III temporary cardiac support (TCS) at time of LVAD implantation was successful in 14 patients (93.3%). End-organ function recovered during ECLS support. No patient needed ongoing ECLS or additional right ventricular support after LVAD implantation. Both in-hospital and 30-day mortality was 6.7% (n = 1). The median duration of LVAD support was 687.9 ± 374.5 days. At the end of the study (follow-up 810.7 +/- 338.9 days), 13 (86.7%) patients were alive. The majority of patients (10 [66.7%]) remained on LVAD support. Transplantation could be performed in 1 (6.7%) patient, 2 (13.3%) patients could be successfully weaned.

Conclusion

LVAD implantation in ECLS patients leads to improvement of INTERMACS level to INTERMACS III TCS status. Excellent mid-term survival comparable to true INTERMACS III-IV patients could be shown. ECLS prior to LVAD as a bridge-to-bridge therapy may help to lower mortality in primarily unstable patients.