Superior neurologic recovery after 15 minutes of normothermic cardiac arrest using an extracorporeal life support system for optimized blood pressure and flow.

OBJECTIVE: Sudden cardiac arrest is one of the leading causes of death. Conventional CPR techniques after cardiac arrest provide circulation with reduced and varying blood flow and pressure. We hypothesize that using pressure- and flow-controlled reperfusion of the whole body improves neurological recovery and survival after 15 min of normothermic cardiac arrest. METHODS: Pigs were randomized in two experimental groups and exposed to 15 min of ventricular fibrillation (VF). After this period, the animals in the control group received conventional CPR with open chest compression (n=6), while circulation in the treatment group (n=6) was established with an extracorporeal life support system (ECLS) to control blood pressure and flow. Follow-up included the assessment of neurological recovery and magnetic resonance imaging (MRI) for up to 7 days. RESULTS: Five of the six animals in the control group died, one animal was resuscitated successfully. In the treatment group, 1/6 could not be separated from ECLS. Five out of the six pigs survived and were transferred to the animal facility. One animal was unable to walk and had to be sacrificed 30 hours after ECLS. The remaining 4 animals of the treatment group and the surviving pig from the control group showed complete neurological recovery. Brain MRI revealed no pathological changes. CONCLUSION: We were able to demonstrate a significant improvement in survival after 15 minutes of normothermic cardiac arrest. These results support our hypothesis that using an ECLS for pressure- and flow-controlled circulation after circulatory arrest is superior to conventional CPR.

Reporting standard for describing first responder systems, smartphone alerting systems, and AED networks.

Standardized reporting of data is crucial for out-of-hospital cardiac arrest (OHCA) research. While the implementation of first responder systems dispatching volunteers to OHCA is encouraged, there is currently no uniform reporting standard for describing these systems. A steering committee established a literature search to identify experts in smartphone alerting systems. These international experts were invited to a conference held in Hinterzarten, Germany, with 40 researchers from 13 countries in attendance. Prior to the conference, participants submitted proposals for parameters to be included in the reporting standard. The conference comprised five workshops covering different aspects of smartphone alerting systems. Proposed parameters were discussed, clarified, and consensus was achieved using the Nominal Group Technique. Participants voted in a modified Delphi approach on including each category as a core or supplementary element in the reporting standard. Results were presented, and a writing group developed definitions for all categories and items, which were sent to participants for revision and final voting using LimeSurvey web-based software. The resulting reporting standard consists of 68 core items and 21 supplementary items grouped into five topics (first responder system, first responder network, technology/algorithm/strategies, reporting data, and automated external defibrillators (AED)). This proposed reporting standard generated by an expert opinion group fills the gap in describing first responder systems. Its adoption in future research will facilitate comparison of systems and research outcomes, enhancing the transfer of scientific findings to clinical practice.

Prolonged cardiac arrest and resuscitation by extracorporeal life support: favourable outcome without preceding anticoagulation in an experimental setting.

State-of-the-art cardiopulmonary resuscitation (CPR) restores circulation with inconsistent blood-flow and pressure. Extracorporeal life support (ECLS) following CPR opens the opportunity for "controlled reperfusion". In animal experiments investigating CPR with ECLS, systemic anticoagulation before induced cardiac arrest is normal, but a major point of dispute, since preliminary heparinization in patients undergoing unwitnessed cardiac arrest is impossible. In this study, we investigated options for ECLS after an experimental 15 minutes normothermic cardiac arrest, without preceding anticoagulation, in pigs. Neurological recovery was assessed by a scoring system, electroencephalography and brain magnetic resonance imaging. Additionally, brain histology was performed on day seven after cardiac arrest. We demonstrated that preliminary heparin administration was not necessary for survival or neurological recovery in this setting. Heparin flushing of the cannulae seemed sufficient to avoid thrombus formation. These findings may ease the way to using ECLS in patients with sudden cardiac arrest.

[CARL-Controlled reperfusion of the whole body]. / CARL ­ kontrollierte Reperfusion des ganzen Körpers: Von der kardiopulmonalen Reanimation zur zielgerichteten eCPR.

BACKGROUND: The incidence and mortality of acute cardiovascular arrest have been consistently high for decades. OBJECTIVE: How to improve the currently unsatisfactory outcome after resuscitation regarding survival and neurological, especially cerebral, sequelae? MATERIAL AND METHODS: Development of a therapeutic approach to curtail ischemia/reperfusion injury in an animal model. Development of a device system optimized for resuscitation that can be used to implement controlled reperfusion of the whole body outside the hospital. RESULTS: Establishment of CARL treatment in the clinic and in the treatment of OHCA patients. Transfer of the CARL treatment and system in a clinical observational study. First case reports in which patients survived OHCA without brain damage even after ischemia times up to 2 h. CONCLUSION: CARL treatment is potentially suitable to treat patients suffering from cardiovascular arrest refractory to treatment even for prolonged periods.

[Extracorporeal cardiopulmonary resuscitation (eCPR)]. / Extrakorporale kardiopulmonale Reanimation (eCPR).

Extracorporeal cardiopulmonary resuscitation (eCPR) is the implementation of extracorporeal membrane oxygenation (ECMO) in selected patients with cardiac arrest and may be considered when conventional CPR efforts fail, as written in the latest international guidelines. eCPR is a complex intervention that requires a highly trained team, specialized equipment, and multidisciplinary support within a healthcare system and it has the risk of several life-threatening complications. However, there are no randomized, controlled studies on eCPR, and valid predictors of benefit and outcome are lacking. Therefore, optimal timing, patient selection, location and method of implementation vary across centers. As utilization of eCPR has increased in recent years and more centers begin to perform eCPR, considerable uncertainties exist in the prehospital setting as well as in the emergency room. However, structured communication and clearly defined processes are essential especially at the interface between prehospital rescue teams and the eCPR team to achieve the highest possible benefit for cardiac arrest patients using eCPR. This article presents an algorithm for structured, evidence-based logistic considerations, patient selection, and implementation of eCPR as well as early care after establishment of extracorporeal life support (ECLS) which are mainly based on the German national recommendations for eCPR of DGIIN, DGK, DGTHG, DGfK, DGNI, DGAI, DIVI and GRC published in 2019 as well as the S3 guideline "Use of extracorporeal circulation (ECLS/ECMO) for cardiac and circulatory failure" and local standard operating procedures of the authors.

The management of acute limb ischemia.

Acute limb ischemia (ALI) is one of the most common vascular emergencies and characterized by sudden worsening of limb perfusion mainly caused by embolization of thrombotic masses or acute graft occlusion. It is a serious condition with potential thread to limb viability accompanied by significant mortality, morbidity and costs. This article provides an overview of etiology, classification and treatment options of ALI ischemia with special focus on the issue of postreperfusion syndrome. The concept of reperfusion injury following limb ischemia and a system for controlled limb reperfusion to offset postreperfusion synsrome is described in detail.

[Freiburg Cardiac Arrest Receiving Team (CART) : Interdisciplinary solution for the acute management of non-traumatic out-of-hospital cardiac arrest]. / Freiburger Cardiac Arrest Receiving Team (CART) : Konzept zur Strukturierung des Behandlungsablaufs nach nichttraumatischem außerklinischem Herz­Kreislauf-Stillstand in einem interdisziplinären Team.

Standard procedures and guidelines provide specific instructions for basic and advanced cardiac life support. Recommendations for the admission of patients from preclinical into clinical structures after successful cardiopulmonary resuscitation (CPR) are available, but only a few are detailed. In the presence of ST-elevation myocardial infarction after return of spontaneous circulation (ROSC), coronary angiography must be performed as soon as possible. However, acute management and consecutive diagnostic procedures after hospital admission are up to the doctor on duty, who can rely on standard internal hospital procedures at best. Despite the enormous progress and new findings in intensive care and emergency medicine, intra-hospital mortality, as well as long-term survival, after CPR remains low and depends on a wide variety of influencing factors. To optimize in-hospital acute care of successfully resuscitated patients, an interdisciplinary admission team, a so-called cardiac arrest receiving team (CART), has been implemented at the University Hospital of Freiburg, Germany. The aim of the CART is to provide primary care to resuscitated patients as quickly and in as standardized a manner as possible with predefined diagnostic and therapeutic pathways by a team with special expertise in the field of CPR and post-resuscitation management. Accordingly, clear criteria for procedures and the location of primary care (e.g. emergency room vs. cardiac catheter laboratory), the composition of the CART and concrete treatment measures were defined.

Myocardial infarction type 1 is frequent in refractory out-of-hospital cardiac arrest (OHCA) treated with extracorporeal cardiopulmonary resuscitation (ECPR).

Extracorporeal cardiopulmonary resuscitation (ECPR) is a last resort treatment option for refractory cardiac arrest performed in specialized centers. Following consensus recommendations, ECPR is mostly offered to younger patients with witnessed collapse but without return of spontaneous circulation (ROSC). We report findings from a large single-center registry with 252 all-comers who received ECPR from 2011-2019. It took a median of 52 min to establish stable circulation by ECPR. Eighty-five percent of 112 patients with out-of-hospital cardiac arrest (OHCA) underwent coronary angiography, revealing myocardial infarction (MI) type 1 with atherothrombotic vessel obstruction in 70 patients (63% of all OHCA patients, 74% of OHCA patients undergoing coronary angiography). Sixty-six percent of 140 patients with intra-hospital cardiac arrest (IHCA) underwent coronary angiography, which showed MI type 1 in 77 patients (55% of all IHCA patients, 83% of IHCA patients undergoing coronary angiography). These results suggest that MI type 1 is a frequent finding and - most likely - cause of cardiac arrest (CA) in patients without ROSC, especially in OHCA. Hospital survival rates were 30% and 29% in patients with OHCA and IHCA, respectively. According to these findings, rapid coronary angiography may be advisable in patients with OHCA receiving ECPR without obvious non-cardiac cause of arrest, irrespective of electrocardiogram analysis. Almost every third patient treated with ECPR survived to hospital discharge, supporting previous data suggesting that ECPR may be beneficial in CA without ROSC. In conclusion, interventional cardiology is of paramount importance for ECPR programs.

The Jarvik 2000 is associated with less infections than the HeartMate left ventricular assist device.

OBJECTIVES: Device-related infections remain a considerable problem of left-ventricular support. We compared the device-related-infections between the HeartMate left ventricular assist device (LVAD) and the Jarvik 2000 permanent LVAD, a device with a novel retroauricular power-supply. METHODS: Between December 2000 and September 2002 we implanted the HeartMate-vented, electrical-system in 11 patients and the permanent Jarvik 2000 in six patients. Total support time was 1626 patient-days (HeartMate, 26-271 days) versus 1246 patient-days (Jarvik 2000, 8-411 days). As potential risk factors for infection we analyzed age, preoperative hospital-days, total protein, cardiac index, maximal oxygen uptake, use of inotropes, LVAD risk-score-index and Aaronson-Mancini-score, intubation time, and intensive care unit stay. We used the Center of Disease Control definitions for surgical site infections. RESULTS: HeartMate-patients were younger than Jarvik 2000 patients (46+/-13 versus 58+/-6 years, P=0.056), there were no other differences in the risk factors. Four HeartMate-patients needed late (>or=48 h) surgical revisions for bleeding/hematomas versus no revisions in the Jarvik 2000 patients. In the HeartMate-patients, there were seven (64%) driveline-infections, five (45%) device-pocket infections, and three (27%) bloodstream-infections, or 0.43 device-related infections/100 patient-days. Infections occurred early (34+/-31 days). Three patients required urgent transplantation due to bloodstream infection. There were no adverse outcomes in the HeartMate-group due to infection. In the Jarvik 2000 patients, there was one driveline-infection (16%) after 270 days of support (0.08 device-related infections/100 patient-days), significantly less than in the HeartMate-group (P=0.044). Driveline infections resolved with antibiotics and local wound care in the Jarvik 2000 patient, but only in one of seven HeartMate-patients. CONCLUSIONS: Implantation of the Jarvik 2000 is associated with less device-related infections than the HeartMate-LVAD. The power-supply of the permanent Jarvik 2000 is suitable for long-term mechanical support.

[Quantifying the damage to conjunctival and corneal cell cultures caused by uv light using CASY (Cell Analysis System). A method for reducing animal experiments]. / Quantifizierung der Schädigung von Bindehaut- und Hornhautzellkulturen durch UV-Licht mit Hilfe des CASY (Zellanalyse)-Systems. Eine Methode zur Reduktion von Tierversuchen.

BACKGROUND: By depletion of stratospheric ozone, enhanced levels of UV radiation reach the surface of the earth. Exposure of the anterior parts of the eye to UV radiation leads to irritation of the conjunctival and corneal cells. METHOD: By the CASY (cell analysis) system the influence of UV radiation on cultures of conjunctival and corneal cells was observed by determination of the cell counts, cell diameter, and the cell volume. RESULTS: By comparing these parameters with the control, damage of the conjunctival and corneal cells by UV radiation can be determined within 2 s of exposure of the cells in quartz glass vials to the UV light. CONCLUSION: By the CASY system the dramatic influence of UV radiation on cells of the anterior parts of the eye can be determined. This system enables objective statements on the cytotoxicity of radiation, chemical substances and drugs on cell cultures without the use of radioactive methods, complicated determination of cell metabolism or staining methods which are difficult to standardize. Also, studies on animals can be reduced by the CASY system.

[Extracorporeal heart and lung replacement procedures]. / Extrakorporale Herz- und Lungenersatzverfahren: "Extracorporeal membrane oxygenation", "extracorporeal life support" und "pumpless extracorporeal lung assist".

The use of extracorporeal support systems in cardiac and/or pulmonary failure is an established treatment option. Although scientific evidence is limited there is an increasing amount of data from individual studies, e.g. Conventional Ventilation or ECMO for Severe Adult Respiratory Failure (CESAR) trial 2010, suggesting that extracorporeal membrane oxygenation (ECMO) as a veno-venous pump-driven system is a life-saving procedure in severe respiratory failure. Initially established as a rescue option for postcardiotomy cardiac failure extracorporeal life support (ECLS) as a pump-driven veno-arterial cardiovascular support system is increasingly being used in cardiogenic shock after myocardial infarction, as bridging to transplantation or as part of extended cardiopulmonary resuscitation. The pumpless extracorporeal lung assist (pECLA) as an arterio-venous pumpless system is technically easier to handle but only ensures sufficient decarboxylation and not oxygenation. Therefore, this method is mainly applied in primarily hypercapnic respiratory failure to allow lung protective ventilation. Enormous technical improvements, e.g. extreme miniaturization of the extracorporeal assist devices must not obscure the fact that this therapeutic option represents an invasive procedure frequently associated with major complications. With this in mind a widespread use of this technology cannot be recommended and the use of extracorporeal systems should be restricted to centers with high levels of expertise and experience.

[Heart surgery in the elderly]. / Herzchirurgische Eingriffe beim älteren Patienten.

Heart surgery has been performed in an increasing number of elderly patients in the recent years. Currently about 20 % of all patients in cardiac surgery are older than 75 years, however their number is increasing constantly. Valve replacement (mainly aortic valve replacement, AVR), coronary artery bypass grafting (CABG) or combined procedures (AVR and CABG) are the most common procedures in the elderly. However, surgical therapy of heart failure, implantation of assist devices or cardiac transplantation have been performed only in a limited number of elderly patients. Surgical pathways in the therapy of coronary artery disease or valve disease are described. Furthermore, age related morbidity and mortality and related surgical options to improve the outcome are discussed.

Pial arteriolar reaction to intravenous administration of bencyclane in the cat.

In a series of 29 experiments in cats, the vasodilatory effect of Bencyclane on pial arterioles was investigated by means of the cranial window technique, using an image-splitting eyepiece, a photometric method or simple microscopic observation. Intravenous injection of 3 mg kg-1 led to vasodilatation in all experiments, yet decreased blood pressure within 30--40 sec until 5--6 min down to 70% of resting pressure. Mean maximal dilatation of arterioles with a 76-micrometers mean resting diameter was 53%. After normalization of blood pressure, arteriolar diameters remained increased by 5--10% for further 10 min, thus indicating increased cerebral blood flow for a total time of about 15 min. During intravenous infusion of 0.2--0.3 mg kg-1min-1 of the drug, pial arterioles dilated by about 10% with blood pressure remaining on resting levels. A higher dosage rate of infusion evoked further vasodilatation, yet parallel decrease of blood pressure.

Cytotoxicity evaluation of soft contact lens care solutions on human conjunctival fibroblasts.

PURPOSE: To determine whether different contact lens care solutions for soft lenses cause damage to human conjunctival cells. METHODS: Primary cultured human conjunctival fibroblasts were incubated with various concentrations of four different commercially available soft contact lens care solutions (OptiFree, Renu, SoloCare, Titmus) at concentrations of 5, 10 and 50 microl/ml medium. Toxicity was examined by determination of (1) the cell viability and mitochondrial activity with the colorimetric MTT test, and (2) the number of living cells with a cell analysis system (CASY 1) as compared with untreated cells. RESULTS: For all four soft contact lens care solutions at a concentration of 5 mul/ml medium, no significant decrease in mitochondrial activity of the human conjunctival fibroblasts was found by the MTT test. At 10 microl/ml, only OptiFree and Titmus reduced mitochondrial viability significantly. The greatest reduction in mitochondrial activity occurred with all of the four soft contact lens care solutions at a concentration of 50 microl/ml. No significant decrease in the number of living conjunctival fibroblasts was observed by CASY 1 even at higher concentrations of the four solutions investigated. CONCLUSION: This in vitro study demonstrates that the examined soft contact lens care solutions induce changes in mitochondria of human conjunctival cells only at higher doses as observed by the MTT test. However, this damage to the mitochondria did not lead to cell death as shown by the cell analysis system.

[Effect of calcium dobesilate on progression of diabetic retinopathy]. / Einfluss von Kalziumdobesilat auf die Progression der diabetischen Retinopathie.

BACKGROUND: The increase of platelet aggregation, plasma and whole blood viscosity and the decrease of red cell deformability in patients with diabetes mellitus may be causative in the development of retinopathy. A therapy influencing these factors maybe prevents retinopathy or slows progression. MATERIAL AND METHODS: In a clinical and prospective study over 2 years 74 patients aged 20 to 69 years with a mild background retinopathy were randomly assigned to take oral 3 x 500 mg calcium dobesilate (Doxium) or no therapy. Both groups did neither differ in demographic nor in laboratory data. In fluorescein angiography following characteristics of retinopathy were graded: microaneurysms, size and outline of foveal avascular zone, capillary loss and severity of dye leakage. Additionally in 15 patients contrast sensitivity, visual fields and oscillatory potentials were investigated. RESULTS: The results of the fluorescein angiographical characteristics revealed no statistically significant difference between both groups. In the oscillatory potentials a significant shortening of latency could be found in both groups, but there was no difference between the groups. CONCLUSION: A 2-years application of calcium dobesilate has no statistically significant influence on the progression of diabetic retinopathy.

Transplantation of an oversized heart.

In response to the limited number of available donors, the criteria for accepting hearts have been expanded. In a 46-year-old female (160 cm, 56 kg) with a body surface area (BSA) of 1.58 m(2), an orthotopic heart transplantation was performed. She received the heart from a 34-year-old male donor (190 cm, 90 kg, BSA 2.58 m(2)). During transplantation, the obvious difference between the donor's heart and the recipient's pericardium did not cause a technical problem. However, the postoperative course was characterized by severe circulation problems. Due to a hemodynamically significant right heart impression, a consecutive pericardectomy had to be performed. After excision of the left and the right side of the pericardium, the patient returned to a stable condition. The consecutive course was without cardiopulmonary problems and the patient was discharged from the hospital 20 days later. The last twelve-month follow-up showed good cardiac function and excellent physical condition. We conclude that an oversized donor heart can be used for heart transplantation as long as the pericardium is left open and a left and right pericardectomy is performed.