Extracorporeal Cardiopulmonary Bypass Research Articles

Abstract 255: Sex Difference of Clinical Outcomes in Patients with Out-of-Hospital Cardiopulmonary Arrest: A Prospective Multicenter Observational Study

OBJECTIVE: There is a strong interest in differences in the outcomes between men and women with out-of-hospital cardiopulmonary arrest (OHCA). The aim of this study is to examine the sex differences of clinical outcomes in patients with OHCA. METHODS: The Japan-Prediction of neurological Outcomes in patients Post cardiac arrest (J-POP) registry is a prospective, multicenter, cohort study to test whether regional cerebral oxygen saturation (rSO2) predicts neurological outcomes in OHCA. In this post-hoc analysis, OHCA were collected after excluding patients exposed to extracorporeal cardiopulmonary bypass from the J-POP registry. The primary outcome measure was a return of spontaneous circulation (ROSC) prior to hospital arrival, and secondary outcome measure was a 90-days neurological outcome. Results: Between May 2011 and July 2012, 1204 consecutive patients, age 72±15 years, 40.4% of women, were examined. Men were younger than women (70±15 vs. 75±15 years, p<0.001), with higher percentage of witness status (53.7% vs. 43.1%, p<0.001), and with higher percentage of rSO2 more than 40% at hospital arrival (12.1% vs. 7.0%, p<0.01), and tended to have higher percentage of cardiac etiology (57.6% vs. 52.4%, p=0.07). 118 (9.8%) patients achieved ROSC prior to hospital arrival. 90-day survival rate was 6.1% (n=73), and 90-day good neurological outcome rate was 3.5% (n=42). Men had higher chance of ROSC (11.7% vs. 7.0%, p<0.01), and good neurological outcome at 90 days (4.6% vs. 1.8%, p=0.01). Multivariate analysis adjusting for age (less than 75 y/o or not), witnessed, received CPR by bystander and etiology revealed that sex male was chosen as an independent predictor for ROSC prior to arrival (RR 1.59, 95%CIs 1.03-2.45). Mantel-Haenszel test adjusting for cardiac etiology also showed that men had higher rate of good neurological outcome (RR 2.47, 95%CIs 1.16-5.23). Conclusion: Our results demonstrate that men had significantly better chance of ROSC regardless of age, received BLS and etiology, and had better neurological prognosis after cardiogenic OHCA. Additional studies are needed to validate these observations for other potential genetic factors.

Desmopressin for reducing postoperative blood loss and transfusion requirements following cardiac surgery in adults

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was, in adult patients undergoing cardiac surgery requiring extracorporeal cardiopulmonary bypass (CPB), does administration of desmopressin acetate (DDAVP) reduce postoperative blood loss and transfusion requirements? Altogether 38 papers were found using the reported search, of which 19 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Perioperative administration of DDAVP in adult patients undergoing cardiac surgery requiring CPB may result in a small but significant reduction in postoperative blood loss. However, this does not translate into a reproducible, clinically significant reduction in exposure to transfusion in unselected patients exposed to CPB. Several sub-groups of patients have been identified in whom DDAVP reduces postoperative blood loss and transfusion requirements. These sub-groups include patients who have received preoperative aspirin within 7 days of surgery, patients with CPB times in excess of 140 min and patients with demonstrable pre- or perioperative platelet dysfunction as determined by TEG analysis or platelet function assays. Platelet dysfunction at the time of surgery may be secondary to preoperative administration of antiplatelet medications, the result of pathological processes such as von Willebrands disease, uraemia or aortic stenosis with its associated sheer stress, as well as operative variables such as prolonged exposure to CPB. The evidence does not support the routine use of DDAVP in all cardiac surgery; indeed, it is clear that there is no significant reduction in postoperative blood loss or transfusion requirements with the administration of DDAVP in patients undergoing isolated coronary artery bypass grafting (CABG) in the absence of the features noted above. Given the absence of a clinically significant reduction in exposure to blood transfusion in unselected patients, we cannot recommend the routine use of DDAVP in patients exposed to CPB. However, DDAVP may reduce postoperative bleeding in patients who have received preoperative aspirin within 7 days of surgery, patients with CPB times in excess of 140 min and patients with demonstrable platelet dysfunction and should be used selectively in these subgroups.

Neurological outcome of extracorporeal cardiopulmonary resuscitation for out of hospital cardiac arrests

Purpose: To evaluate the efficacy of extracorporeal cardiopulmonary resuscitation (ECPR) using clinical neurological outcome. Methods: Patients were included in this single center retrospective analysis between 2003 and 2012, if they met following criteria: 1. out of hospital cardiac arrest who were still in cardiac arrest in any rhythm on arrival to the hospital, 2. underwent emergent extracorporeal cardiopulmonary bypass using veno-arterial extracorporeal membrane oxygenation (V-A ECMO) as an adjunct to conventional CPR. Trauma patients were excluded. Total of 64 patients were identified and evaluated on three clinical neurological outcome categories: neurologically intact, comatose consisting of severely disabled, vegetative state or brain death, and death. The time interval from collapse to induction of V-A ECMO on each category were compared. Analyses were made on neurological outcomes based on initial rhythm and types of disease. Comparison was made on median lengths of hospital stay in each outcome. Results: Of 64 patients, 18 patients (28%) were neurologically intact, 14 patients (22%) were comatose, and 32 patients (50%) were dead on discharge. Median time intervals from collapse to induction of V-A ECMO were 37 minutes for neurologically intact patients (p<0.05), 60 minutes for comatose patients, 60 minutes for patients who died. Neurological outcomes of 42 patients with ventricular fibrillation/ventricular tachycardia as an initial rhythm were as follows: 13 (31%) neurologically intact, 10 (24%) comatose, 19 (45%) dead. For 13 patients with pulseless electric activity (PEA) and 8 patients with asystole, outcomes were as follows in the same order shown above: PEA 4 (31%), 1 (8%), 8 (62%), asystole 0 (0%), 3 (38%), 5 (63%). Out of 51 patients with cardiac etiology, 11 (21.6%) were neurologically intact, 12 (23.5%) were comatose, and 28 (54.9%) were dead. In contrast, of 13 patients with non-cardiac etiology, 7 (53.8%) were neurologically intact, 2 (15.4%) were comatose, and 4 (30.8%) were dead. Median length of hospital stay for patients with neurologically intact, comatose, death were 11.5 days, 24.5 days, 2 days, respectively. Conclusion: ECPR yields 28% survival with good neurological outcome to otherwise futile patient population.

Akzidentelle Hypothermie

Uncertainty exists on how to treat patients suffering from accidental hypothermia and on the optimal transport decisions. The aim of this review is to provide an updated evidence-based reference for the pre-hospital and in-hospital management of patients with accidental hypothermia and for the transport decisions required to facilitate treatment. Advances in the efficiency and availability of rewarming techniques have improved the prognosis for patients presenting with hypothermia. For hypothermic patients with a core body temperature ≥ 28 °C without cardiac instability there is increasing evidence to support the use of active external and minimally invasive rewarming techniques (e.g. chemical, electrical or forced air heating packs, blankets and warm parenteral fluids). Hypothermic patients with cardiac instability (i.e. systolic blood pressure < 90 mmHg, ventricular arrhythmia and core body temperature < 28 °C) should be rewarmed with active external and minimally invasive rewarming techniques in a hospital which also has circulation substituting venous-arterial extracorporeal membrane oxygenation (VA-ECMO) and cardiopulmonary bypass (CBP) facilities. In cardiac arrest patients VA-ECMO may be a better treatment option than CBP and survival rates of 100 % can be achieved compared to ~ 10 % with traditional methods (e.g. body cavity lavage). Early transport to a hospital appropriately equipped for rewarming has the potential to decrease complication rates and improve survival.

Applications of Artificial Heart Research to the Life-Saving Device

Applications of Artificial Heart Research to the Life-Saving Device

Preoperative anaemia is a negative factor in aortic valve surgery

The impact of anaemia on patients undergoing aortic valve surgery is poorly understood. Anaemia is associated with aortic valve surgery. A recent article by Elmistekawy et al. [1] demonstrated that preoperative anaemia is a common finding in patients undergoing aortic valve surgery and is an important and potentially modifiable risk factor for postoperative morbidity and mortality. This analysis suggests that anaemia may serve as a negative factor in aortic valve surgery. Other studies have been carried out on this topic. Major surgery in a patient with pancytopenia might be associated with increased surgical risks, particularly for bleeding and infection. Halliday et al. [2] demonstrated that, in a logistic regression model, coexisting vascular disease, diabetes and preprocedural anaemia significantly affected the incidence of life-threatening or major bleeding. Furthermore, Kitamura et al. [3] have shown that postoperatively, a patient developed paravalvular leak and haemolytic anaemia, subsequently undergoing reoperation. Also, Van Mieghem et al. [4] found that baseline anaemia is common in patients undergoing transcatheter aortic valve implantation, forecasts a need for more red blood cell transfusions and is associated with increased 1-year mortality. Moreover, hypercoagulative states have been observed in patients with alpha-thalassaemia as beta-thalassaemia; therefore, special attention should be taken in perioperative anticoagulation therapy. Kawase et al. [5] indicated that haemolytic anaemia with aortic stenosis resolved by urgent aortic valve replacement. However, Lee and Lee [6] reported a successful cardiac surgery with extracorporeal cardiopulmonary bypass in a patient with severe aortic valve insufficiency and concomitant idiopathic aplastic anaemia. In summary, these findings suggest that anaemia may be a negative factor in aortic valve surgery. Therapeutic agents targeting anaemia might result in innovative new therapies for aortic valve surgery. Finally, we greatly enjoyed reading the article by Elmistekawy et al. and believe that the prevention and treatment of anaemia may be useful in aortic valve surgery.

Heparin inhibits angiotensin II-induced vasoconstriction on isolated mouse mesenteric resistance arteries through Rho-A- and PKA-dependent pathways

Heparin is commonly used to treat intravascular thrombosis in children undergoing extracorporeal membrane oxygenation or cardiopulmonary bypass. These clinical circumstances are associated with elevated plasma levels of angiotensin II (Ang II). However, the mechanisms by which heparin modulates vascular reactivity of Ang II remain unclear. We hypothesized that heparin may offset Ang II-induced vasoconstriction on mesenteric resistance arteries through modulating the Rho-A/Rho kinase pathway. Vascular contractility was studied by using pressurized, resistance-sized mesenteric arteries from mice. Rho-A activation was measured by pull-down assay, and myosin light chain or PKA phosphorylation by immunoblotting. We found that heparin significantly attenuated vasoconstriction induced by Ang II but not that by KCl. The combined effect of Ang II with heparin was almost abolished by a specific Rho kinase inhibitor Y27632. Ang II stimulated Rho-A activation and myosin light chain phosphorylation, both responses were antagonized by heparin. Moreover, the inhibitory effect of heparin on Ang II-induced vasoconstriction was reversed by Rp-cAMPS (cAMP-dependent PKA inhibitor), blunted by ODQ (soluble guanylate cyclase inhibitor), and mimicked by a cell-permeable cGMP analogue, 8-Br-cGMP, but not by a cAMP analogue. PKC and Src kinase were not involved. We conclude that heparin inhibits Ang II-induced vasoconstriction through Rho-A/Rho kinase- and cGMP/PKA-dependent pathways.

Resuscitation of avalanche victims: Evidence-based guidelines of the international commission for mountain emergency medicine (ICAR MEDCOM): Intended for physicians and other advanced life support personnel

BackgroundIn North America and Europe ∼150 persons are killed by avalanches every year. MethodsThe International Commission for Mountain Emergency Medicine (ICAR MEDCOM) systematically developed evidence-based guidelines and an algorithm for the management of avalanche victims using a worksheet of 27 Population Intervention Comparator Outcome questions. Classification of recommendations and level of evidence are ranked using the American Heart Association system. Results and conclusionsIf lethal injuries are excluded and the body is not frozen, the rescue strategy is governed by the duration of snow burial and, if not available, by the victim's core-temperature. If burial time ≤35min (or core-temperature ≥32°C) rapid extrication and standard ALS is important. If burial time >35min and core-temperature <32°C, treatment of hypothermia including gentle extrication, full body insulation, ECG and core-temperature monitoring is recommended, and advanced airway management if appropriate. Unresponsive patients presenting with vital signs should be transported to a hospital capable of active external and minimally invasive rewarming such as forced air rewarming. Patients with cardiac instability or in cardiac arrest (with a patent airway) should be transported to a hospital for extracorporeal membrane oxygenation or cardiopulmonary bypass rewarming. Patients in cardiac arrest should receive uninterrupted CPR; with asystole, CPR may be terminated (or withheld) if a patient is lethally injured or completely frozen, the airway is blocked and duration of burial >35min, serum potassium >12mmolL−1, risk to the rescuers is unacceptably high or a valid do-not-resuscitate order exists. Management should include spinal precautions and other trauma care as indicated.

Colloids in the intensive care unit

The most recent published evidence on the use of colloids versus crystalloids in critical care is reviewed, with a focus on population-dependent differences in safety and efficacy. Colloids offer a number of theoretical advantages over crystalloids for fluid resuscitation, but some colloids (e.g., hydroxyethyl starch solutions, dextrans) can have serious adverse effects, and albumin products entail higher costs. The results of the influential Saline Versus Albumin Fluid Evaluation (SAFE) trial and a subsequent SAFE subgroup analysis indicated that colloid therapy should not be used in patients with traumatic brain injury and other forms of trauma due to an increased mortality risk relative to crystalloid therapy. With regard to patients with severe sepsis, two meta-analyses published in 2011, which collectively evaluated 82 trials involving nearly 10,000 patients, indicated comparable outcomes with the use of either crystalloids or albumins. For patients requiring extracorporeal cardiopulmonary bypass (CPB) during heart surgery, the available evidence supports the use of a colloid, particularly albumin, for CPB circuit priming and postoperative volume expansion. In select patients with burn injury, the published evidence supports the use of supplemental colloids if adequate urine output cannot be maintained with a crystalloid-only rescue strategy. The results of the SAFE trial and a subgroup analysis of SAFE data suggest that colloids should be avoided in patients with trauma and traumatic brain injury. There are minimal differences in outcome between crystalloids and hypo-oncotic or iso-oncotic albumin for fluid resuscitation in severe sepsis; in select populations, such as patients undergoing cardiac surgery, the use of iso-oncotic albumin may confer a survival advantage and should be considered a first-line alternative.

Bivalirudin and post-cardiotomy ECMO: a word of caution

Bivalirudin has been proposed as the sole anticoagulant in patients under extracorporeal membrane oxygenation (ECMO) or cardiopulmonary bypass. Owing to the pharmacodynamic properties of bivalirudin, areas of blood stagnation should be carefully avoided in order to limit the risk of thrombosis. The ECMO circuit has no reservoir and is usually devoid of blood stagnation areas. Conversely, under some circumstances, intracardiac blood stagnation areas may exist. In this case, there is a potential risk for the spontaneous formation of an intracardiac thrombus. We suggest that, under bivalirudin anticoagulation, a minimal degree of intracardiac blood flow with left heart valve movement is allowed.

Is time on cardiopulmonary bypass during cardiac surgery associated with acute kidney injury requiring dialysis?

It is commonly accepted that the longer the time on extracorporeal cardiopulmonary bypass (CPB), the higher is the likelihood of developing acute renal failure requiring dialysis (ARF-D). Nonetheless, previous works elicited conflicting evidence. We investigated the relationship between CPB duration and ARF-D occurrence. Data were extracted from a large observational study. All factors independently associated with ARF-D were detected. Overall, 11,092 case record forms were analyzed. At the univariate analyses, time on CBP was associated with an increase in the ARF-D risk (odds ratio of fifth vs. first quintile of CBP time: 3.84; 95% confidence interval: 2.58-5.7; P < 0.001). However, after adjusting for confounders, the association between time on CBP and ARF-D lost its statistical significance. In this large dataset, CBP time did not predict ARF-D occurrence. These results might suggest that an accurate risk assessment might be more important than time on CPB in determining ARF-D occurrence.

Translational Research in Pediatric Extracorporeal Life Support Systems and Cardiopulmonary Bypass Procedures: 2011 Update

Over the past 6 years at Penn State Hershey, we have established the pediatric cardiovascular research center with a multidisciplinary research team with the goal to improve the outcomes for children undergoing cardiac surgery with cardiopulmonary bypass (CPB) and extracorporeal life support (ECLS). Due to the variety of commercially available pediatric CPB and ECLS devices, both in vitro and in vivo translational research have been conducted to achieve the optimal choice for our patients. By now, every component being used in our clinical settings in Penn State Hershey has been selected based on the results of our translational research. The objective of this review is to summarize our translational research in Penn State Hershey Pediatric Cardiovascular Research Center and to share the latest results with all the interested centers.

First experience with the new Cardiohelp life support system

Portable miniaturized extracorporeal cardiopulmonary bypass systems emerge as a new tool for perioperative management in patients with cardiopulmonary failure. We report the initial experience with the new Cardiohelp system.

Hybrid Endovascular Repair for Type I Endoleak after Stent Grafting of Chronic Stanford Type B Aortic Dissection -A case report-

A 67 years old male patient was admitted with back pain that had recurred from 6 months previously. Eleven years previously, he underwent stent grafting at the descending thoracic aorta for a chronic Stanford type B aortic dissection. The preoperative computed tomography showed aortic dissection from the origin of the left subclavian artery to the bifurcation of the abdominal aorta, and there was a type Ⅰ endoleak at the proximal portion of the stent graft and aneurysmal dilatation of the descending aorta. A hybrid endovascular repair was successfully performed, and this involved debranching and rerouting the aortic arch vessels under extracorporeal cardiopulmonary bypass and then this was followed 13 days later by stenting in the ascending aorta, the aortic arch and the descending aorta. The postoperative computed tomography showed complete exclusion of the type Ⅰ endoleak. After discharge, he has been followed up for 8 months without any problems.

Mini extracorporeal circuit cardiopulmonary bypass system: a review

Improved knowledge of the pathophysiological processes experienced in response to cardiopulmonary bypass has led to new developments in extracorporeal technology and understanding. The use of mini extracorporeal circuits (MECC) is rapidly expanding in clinical practice. The mini extracorporeal circuit differs by a greatly reduced tubing length and the number of components when compared with current circuit designs. The MECC is believed to offer potential benefits to the surgical patient by reducing the systemic inflammatory response that remains strongly implicated in post-operative organ dysfunction. We present a review of the available literature and find the MECC to show an acceptable safety profile with a reduction in post-operative complications and transfusion requirements and no evidence of any negative impairment to the surgeon, anaesthetist or perfusionist. The observed post-bypass inflammatory response is seen to be lower after MECC bypass and this is of clear clinical benefit.

Glutamine administration in patients undergoing cardiac surgery and the influence on blood glutathione levels

Cardiac surgery with an extracorporeal circulation cardiopulmonary bypass (CPB) is characterized by an oxidative stress response. Glutathione (GSH) belongs to the major antioxidative defense. In metabolic stress, glutamine (GLN) may be the rate-limiting factor of GSH synthesis. Decreased GLN plasma levels were observed after various critical states. We evaluated, in patients undergoing open heart surgery with CPB, the effects of a peri-operative GLN supplementation on GSH in whole blood and assessed their influence on the Sequential Organ Failure Assessment score and the intensive care unit length of stay. In this prospective, randomized, double-blinded study, we included 60 patients (age older than 70 years, ejection fraction <40% or mitral valve replacement) undergoing an elective cardiac surgery with CPB. We randomly assigned each subject to receive an infusion with either GLN (0.5 g/kg/day, group 1) or an isonitrogeneous, isocaloric, isovolemic amino acids solution (group 2) or saline (group 3). From the first post-operative day GLN plasma levels in group 1 were significantly increased compared with the other groups. With saline GSH the levels decreased significantly post-operatively compared with GLN. We observed a significant correlation between GLN delivery and GSH levels. A peri-operative high-dose GLN infusion increased plasma GLN concentrations and maintained the GSH levels after cardiac surgery with CPB.

Prostate-specific antigen kallikrein and the heart

Currently, there is growing interest regarding prostate-specific antigen (PSA) and the cardiovascular system. Increased PSA serum levels have been reported after prolonged cardiopulmonary resuscitation, cardiac surgery, extracorporeal cardiopulmonary bypass, acute myocardial infarction (AMI) and coronary artery stenting. The possible role of PSA in cardiac events has been questioned due to the finding of PSA decrease during AMI and by the correlation of variation in PSA levels with coronary lesions and occurrence of major adverse cardiac events. Complexed PSA forms and uncomplexed PSA forms are observed in the bloodstream but the increasing formation of irreversible bound PSA seems to be a crucial finding during AMI. Large studies need to be carried out to confirm these preliminary results and to elucidate unclear aspects. These findings present many potential directions for future research including the role of uncomplexed forms of PSA, the possible distribution of PSA in the heart, the relative expression levels in heart disease states, the mode of expression regulation and other potential specific substrates. The journey of PSA investigation could be longer than initially expected.

HIT Happens: Diagnosing and Evaluating the Patient with Heparin-Induced Thrombocytopenia

HIT Happens: Diagnosing and Evaluating the Patient with Heparin-Induced Thrombocytopenia

A Cross-sectional Survey of Levels of Care and Response Mechanisms for Evolving Critical Illness in Hospitalized Children

Recognition and treatment of evolving critical illness is a fundamental element of hospital care. Hospital systems should triage patients to receive appropriate levels of care. We describe here the levels of care, the frequency of near or actual cardiopulmonary arrest (code-blue events), identification mechanisms, and responses to evolving critical illness in hospitalized children. A cross-sectional telephone survey of Canadian and American hospitals with > or = 50 pediatric acute care beds or > or = 2 pediatric wards was performed. Regression analysis identified factors associated with the frequency of code-blue events after adjustment for hospital volume. Responses from 388 (84%) hospitals identified the 181 eligible pediatric hospitals included in this survey. All had a PICU, 99 (55%) had high-dependency units, 101 (56%) had extracorporeal membrane oxygenation therapy, and 69 (38%) used extracorporeal membrane oxygenation therapy for refractory cardiopulmonary arrest. All of the hospitals had immediate-response teams. They were activated 4676 times in the previous 12 months. Twenty-four percent of hospitals had activation criteria for immediate-response teams. Urgent-response teams to treat children who were clinically deteriorating but not at immediate risk of cardiopulmonary arrest were available in 136 (75%) hospitals; 29 (17%) had formal medical emergency teams, and 92 (51%) consulted the PICU. Code-blue events were more common in hospitals with extracorporeal membrane oxygenation therapy, cardiopulmonary bypass, and larger PICU size. Currently, the organization of Canadian and American pediatric hospitals includes dedicated areas to match patient acuity and additional personnel to stabilize and facilitate transfer. The functioning of these systems of care results in calls for immediate medical assistance for ward patients approximately 5000 times annually.

Cardiac Surgery in a Patient with Idiopathic Aplastic Anemia: A Case Report

Major surgery in a patient with pancytopenia might be associated with increased surgical risks, especially for bleeding and infection. A 66-yr-old man was admitted to the hospital due to shortness of breath. His dyspnea was classified by the New York Heart Association (NYHA) as functional class III. Prior to admission, he had a 5-yr history of medical management for idiopathic aplastic anemia. The severity of aplastic anemia of the patient was graded as non-severe aplastic anemia. Echocardiography revealed reduced left ventricular function and severe aortic valve regurgitation (grade IV) with left ventricular end diastolic dimension measuring 87 mm. Because of dyspnea and echocardiographically documented aortic valve insufficiency, the patient underwent elective aortic valve replacement. Although extracorporeal circulation for valve operations might be associated with aggravation of impaired blood cell function, the patient recovered from surgery uneventfully. Here, we report a successful cardiac surgery with extracorporeal cardiopulmonary bypass in a patient with severe aortic valve insufficiency and concomitant idiopathic aplastic anemia.