Dirk Lunz

Universität Regensburg, Regensburg, Bavaria, Germany

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Publications (17)36.35 Total impact

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    ABSTRACT: Due to the technical advances in pumps, oxygenators and cannulas, veno-arterial extracorporeal membrane oxygenation (va-ECMO) or extracorporeal life support (ECLS) has been widely used in emergency medicine and intensive care medicine for several years. An accepted indication is peri-interventional cardiac failure in cardiac surgery (postcardiotomy low cardiac output syndrome). Furthermore, especially the use of va-ECMO for other indications in critical care medicine, such as in patients with severe sepsis with septic cardiomyopathy or in cardiopulmonary resuscitation has tremendously increased. The basic indications for va-ECMO are therapy refractory cardiac or cardiopulmonary failure. The fundamental purpose of va-ECMO is bridging the function of the lungs and/or the heart. Consequently, this support system does not represent a causal therapy by itself; however, it provides enough time for the affected organ to recover (bridge to recovery) or for the decision for a long-lasting organ substitution by a ventricular assist device or by transplantation (bridge to decision). Although the outcome for bridged patients seems to be favorable, it should not be forgotten that the support system represents an invasive procedure with potentially far-reaching complications. Therefore, the initiation of these systems needs a professional and experienced (interdisciplinary) team, sufficient resources and an individual approach balancing the risks and benefits. This review gives an overview of the indications, complications and contraindications for va-ECMO. It discusses its advantages in organ transplantation and transport of critically ill patients. The reader will learn the differences between peripheral and central cannulation and how to monitor and manage va-ECMO.
    Der Anaesthesist 07/2014; · 0.85 Impact Factor
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    ABSTRACT: Extracorporeal life support (ECLS) is a rescue option in critically ill patients. Since fast available and appropriate for respiratory and circulatory failure, it is frequently applied in resuscitation scenarios. Neurological injury is a complication common in ECLS patients limiting outcome, particularly after resuscitation. In this study, the institutional ECLS database was used to correlate neuron-specific enolase (NSE) serum peak values with outcome of patients supported with venoarterial (VA) ECLS during cardiopulmonary resuscitation (CPR). From January 2011 to August 2012, 31 patients were provided with a VA ECLS during CPR (external cardiac massage). Serum NSE peaks were monitored and correlated with neurological outcome and hospital mortality. Patients were divided into two groups with mild-to-moderate and high NSE levels (cut-off value 100 μg/l). High NSE levels were seen in 7 patients (mean 218 ± 155 μg/l) and mild-to-moderate levels in 24 patients (50 ± 23 μg/l, P = 0.0001). Duration of extracoporeal support was comparable in both groups (6.3 ± 7.5 vs 5.0 ± 4.5 days, P = n.s.). Patients with mild-to-moderate NSE levels were significantly older than those with high NSE levels (58 ± 16 vs 44 ± 15 years, P = 0.02). Six patients with high NSE levels (86%) developed severe neurological complications. Though 4 patients could be weaned from extracorporeal support, hospital mortality was 86% (6 patients). In contrast, patients with mild-to-moderate NSE levels had a hospital mortality of 46% (11 patients). Eighteen patients (75%) could be weaned from the device, and incidence of major neurological events was 29% (6 patients) only. Serum pH and lactate levels before ECLS implantation were significantly lower in patients with mild-to-moderate NSE values (pH: 7.23 ± 0.04 vs 6.93 ± 0.12, P = 0.039; lactate: 106 ± 11 vs 161 ± 16 mg/l, P = 0.023). High NSE serum levels after ECLS correspond to poor neurological outcome and considerable mortality. Therefore, early neuroimaging is reasonable for determining therapeutic strategies in patients with high NSE peaks after resuscitation and extracorporeal support.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 07/2013; · 2.40 Impact Factor
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    ABSTRACT: OBJECTIVES Based on continuous technical innovations and recent research, extracorporeal membrane oxygenation (ECMO) has become a promising tool in the treatment of patients with acute (cardio)pulmonary failure. Nevertheless, any extracorporeal technique requires a high degree of experience and knowledge, so that a restriction to specialized centres seems to be reasonable. As a consequence of this demand, the need for inter-hospital transfer of patients with severely impaired (cardio)pulmonary function is rising. Unfortunately, most of the ECMO devices used in the clinical setting are not suitable for inter-hospital transport because of their size, weight or complexity. In this article, we describe our first experiences with the airborne transport of 6 patients on a new portable, miniaturized and lightweight extracorporeal circulation system, the Medos deltastream® DP3.METHODS Six patients suffering acute respiratory failure were taken on venovenous ECMO (DP3) out-of-centre and transferred to the University Medical Center Regensburg by helicopter. All cardiorespiratory-relevant parameters of the patients and the technical functioning of the device were continuously monitored and documented.RESULTSImplantation of the device and air-supported transport were performed without any technical complications. The patients were transported from a distance of 66-178 km, requiring a time of 40-120 min. With the help of the new deltastream® DP3 ECMO device, a prompt stabilization of the cardiopulmonary function could be achieved in all patients. One patient was under ongoing cardiopulmonary resuscitation by the time our ECMO team arrived at the peripheral hospital and died shortly after arrival in the central emergency ward.CONCLUSIONS Our experience shows that the deltastream® DP3 is an absolutely reliable and safe ECMO device that could gain growing importance in the field of airborne transportation of patients on ECMO due to its unsophisticated, miniaturized and lightweight characteristics.
    Interactive Cardiovascular and Thoracic Surgery 07/2013; · 1.11 Impact Factor
  • European Journal of Intensive Care Medicine 05/2013; · 5.17 Impact Factor
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    ABSTRACT: OBJECTIVES: To report our center's experience using veno-arterial extracorporeal membrane oxygenation (vaECMO) in transcatheter aortic valve implantation (TAVI). BACKGROUND: In TAVI, short-term mortality closely relates to life threatening procedural complications. VaECMO can be used to stabilize the patient in emergency situations. However, for the prophylactic use of vaECMO in very high-risk patients undergoing TAVI there is no experience. METHODS: From January 2009 to August 2011, we performed 131 TAVI. Emergency vaECMO was required in 8 cases (7%): ventricular perforation (n=3), hemodynamic instability/cardiogenic shock (n=4), hemodynamic deterioration due to ventricular tachycardia (n=1). Since August 2011, during 83 procedures, prophylactic vaECMO was systematically used in very high-risk patients (n=9, 11%) and emergency ECMO in one case (1%) due to ventricular perforation. RESULTS: Median logistic EuroScore in prophylactic vaECMO patients was considerably higher compared to the remaining TAVI population (30% vs. 15%, p=.0003) while in patients with emergency vaECMO it was comparable (18% vs. 15%, p=.08). Comparing prophylactic to emergency vaECMO, procedural success and 30-day mortality were 100% vs. 44% (p=.03) and 0% vs. 44% (p=.02), respectively. Major vascular complications and rate of life threatening bleeding did not differ between both groups (11% vs. 11%, p=.99 and 11% vs. 33%, p=.3) and were not vaECMO-related. CONCLUSIONS: Life-threatening complications during TAVI can be managed using emergency vaECMO but mortality remains high. The use of prophylactic vaECMO in very high-risk patients is safe and may be advocated in selected cases. © 2013 Wiley-Liss, Inc.
    Catheterization and Cardiovascular Interventions 04/2013; · 2.51 Impact Factor
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    ABSTRACT: Extracorporeal membrane oxygenation (ECMO) has been successfully used to support patients with cardiac arrest failing to respond to conventional cardiopulmonary resuscitation (CPR). Preimplant factors being indicative for success are unknown up to now. The study describes single center experience with special focus on differences between survivors and nonsurvivors. Between 2002 and 2009, 103 patients were supported within the scope of CPR by means of ECMO. Besides primary diagnosis, duration, and outcome, pH, lactate, mean arterial pressure, aspartate aminotransferase, bilirubin, catecholamine dosage, and oxygenation ratio before ECMO, after 2 h, 1 day, and at explantation were analyzed. One hundred three patients (51.2 ± 16 years, 35 women, 68 men) were analyzed. Primary cardiac failure led to CPR in 54%. Duration of support was 4.8 ± 0.6 days. Twenty-nine (28.1%) patients survived to hospital discharge. On ECMO support, pH, lactate, and mean arterial pressure improved significantly. Catecholamine dosage was significantly reduced after ECMO implantation. Demographic data and primary diagnosis revealed no significant influence on outcome. pH, lactate, creatinine, and bilirubin differed significantly between survivors and nonsurvivors in the course of ECMO support. ECMO support during CPR reliably improves the circulatory and respiratory situation. Considering observed survival critical patient selection is mandatory. Although there are several significant differences between surviving patients and patients with fatal outcome, patient selection turns out to be difficult as clinically relevant factors show only limited predictive value. Future research should focus on better defining a population that may be best of all suited for the use of ECMO support in CPR.
    Artificial Organs 02/2013; 37(2):150-6. · 1.96 Impact Factor
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    ABSTRACT: Veno-venous extracorporeal membrane oxygenation (vvECMO) conventionally requires the cannulation of two vessels. Here we report our initial experience with the "Wang-Zwische" (WZ) double-lumen cannula.In a group of n = 36 patients single venous cannulation for vvECMO was performed. A retrospective analysis was executed. A comparison of flow characteristics to standard two-vessel cannulation was performed. Mean age of the patient population was 48 ± 15 years (body mass index [BMI] 32 ± 13 kg/m). In n = 32 patients (89%) the cannula was implanted percutaneously under echo or fluoroscopic guidance in less than 30 minutes. Nine patients were partially mobilized on extracorporeal membrane oxygenation (ECMO) support. Oxygenation (partial arterial oxygen tension [PaO2]/fraction of inspired oxygen [FiO2]) improved significantly in all patients from 66 mm Hg (interquartile range [IQR] 58-87 mm Hg) before ECMO to 117 mm Hg (IQR 95-195 mm Hg, p = 0.001) after 24 hours. In seven patients (19%) nonfatal adverse events occurred, including three dislocations, two partial cannula thrombosis, one ventricular perforation, and one retroperitoneal hemorrhage. The negative pressures for drainage at a flow of 2.5 L/min were significantly lower in a standard (S) two-vessel approach compared with a WZ approach (S: -9 mm Hg; IQR -3 to -24 mm Hg, vs. WZ: -23 mm Hg; IQR -4 to -40 mm Hg; p = 0.04). The WZ cannula offers sufficient gas exchange in addition to certain advantages over standard cannulation, including facilitated cannulation in selected patients and improved mobilization.
    ASAIO journal (American Society for Artificial Internal Organs: 1992) 09/2012; · 1.39 Impact Factor
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    ABSTRACT: BACKGROUND: The efficiency of cardiopulmonary resuscitation (CPR) training is dependent upon different influencing factors, such as the presented concepts, the participants' willingness to learn, and the interval between training sessions. However, the optimal interval for refreshing CPR training is less clear. OBJECTIVE: We evaluated the perceived need of simulator-based CPR training for nurses and correlated it with their clinical experience. METHODS: The 60 invited nurses were trained in simulator-based CPR. Knowledge about adult advanced life support was evaluated using a questionnaire after training, and participants rated their desired individual frequency of simulator-based training as well as the value of the presented training using a six-point Likert scale. The same questions were asked again after 1 year. RESULTS: All participants agreed about the usefulness of this type of simulator-based training. The average number of correct answers about typical facts in adult advanced life support showed an almost bell-shaped distribution, with the highest point at 6-15 years of clinical experience and the lowest points at≤5 and≥21 years. The desired training-frequency need was inversely correlated with clinical experience. CONCLUSIONS: There is a high interest in CPR training among nursing staff. Self-assessment about the training-frequency need was inversely correlated with clinical experience. However, the average number of correct answers on resuscitation questions decreased with clinical experience. Therefore, the training effectiveness seems to be extremely dependent on clinical experience, and therefore, training experienced senior nurses might be more challenging than training novice nurses.
    Journal of Emergency Medicine 03/2012; · 1.33 Impact Factor
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    ABSTRACT: The role of female gender in cardiac surgery is still controversial. We examined the impact of gender on mortality after coronary artery bypass grafting (CABG) with minimized extracorporeal circulation (MECC). Between January 2004 and May 2009, 1,662 patients (439 females, 1,223 males) underwent CABG with MECC at the University Medical Center Regensburg. Perioperative data were retrospectively analyzed; primary end point was in-hospital mortality. At operation, women were older, had a higher prevalence of diabetes and impaired renal function, and underwent more often non-elective surgery. Unadjusted mortality was significantly lower for men and than for women (2.3 vs. 5.7%; p = 0.001). Risk-adjusted mortality rates were derived by stepwise logistic regression. The final model reduced the gender-related mortality gap from 147 to 32%. Goodness of fit and discriminatory performance (AUC = 0.83) were good. Female gender, however, could not be identified as an independent risk factor for adverse outcome (OR 1.6; 95% CI 0.8-3.4). Risk-adjusted mortality was calculated as 4.9% in females and 2.6% in males. Low body surface area (<1.66 m(2)) was associated with excess mortality in females. Gender-related disparity in outcome still remains present after surgery with minimized extracorporeal circulation. However, female gender per se is not an independent risk factor for in-hospital mortality, but close attention should be paid on modifiable risk factors.
    Clinical Research in Cardiology 01/2012; 101(6):437-44. · 3.67 Impact Factor
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    ABSTRACT: Intensive care unit-acquired weakness (ICUAW) is a severe complication in critically ill patients which has been increasingly recognized over the last two decades. By definition ICUAW is caused by distinct neuromuscular disorders, namely critical illness polyneuropathy (CIP) and critical illness myopathy (CIM). Both CIP and CIM can affect limb and respiratory muscles and thus complicate weaning from a ventilator, increase the length of stay in the intensive care unit and delay mobilization and physical rehabilitation. It is controversially discussed whether CIP and CIM are distinct entities or whether they just represent different organ manifestations with common pathomechanisms. These basic pathomechanisms, however, are complex and still not completely understood but metabolic, inflammatory and bioenergetic alterations seem to play a crucial role. In this respect several risk factors have recently been revealed: in addition to the administration of glucocorticoids and non-depolarizing muscle relaxants, sepsis and multi-organ failure per se as well as elevated levels of blood glucose and muscular immobilization have been shown to have a profound impact on the occurrence of CIP and CIM. For the diagnosis, careful physical and neurological examinations, electrophysiological testing and in rare cases nerve and muscle biopsies are recommended. Nevertheless, it appears to be difficult to clearly distinguish between CIM and CIP in a clinical setting. At present no specific therapy for these neuromuscular disorders has been established but recent data suggest that in addition to avoidance of risk factors early active mobilization of critically ill patients may be beneficial.
    Der Anaesthesist 10/2011; 60(10):887-901. · 0.85 Impact Factor
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    ABSTRACT: In patients with severe cardiopulmonary failure extracorporeal assist devices are to support patients during resuscitation, for transportation, until organ recovery, and as bridge to further therapeutic modalities. We report on our first experience with the new Cardiohelp system for interhospital transfer of cardiopulmonarily compromised patients. The Cardiohelp system was used for transportation and in-house treatment in six male patients with a mean age of 41±17 years. Five patients suffered respiratory failure; one patient with acute myocardial infarction was in profound cardiogenic shock. Accordingly, the Cardiohelp system was implanted as a venovenous extracorporeal membrane oxygenation (ECMO) in five patients and as a venoarterial system in one patient. The preECMO ventilation time was 0.5-4 days. The patients were transported to our institution by car (n=1) or helicopter (n=5) over a distance of 80-5850 km. The subsequent in-house ECMO support was continued with the Cardiohelp and lasted for 5-13 days. PostECMO ventilation was one to 25 days. A 100% survival was achieved. The portable Cardiohelp system allows location-independent stabilization of cardiopulmonary compromised patients with consecutive interhospital transfer and in-house treatment. The integrated sensors, which register arterial and venous line pressure, blood temperature, hemoglobin as well as SvO(2), greatly alleviate its management and considerably increase safety.
    Interactive Cardiovascular and Thoracic Surgery 03/2011; 12(6):978-81. · 1.11 Impact Factor
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    ABSTRACT: To evaluate the effect of the inotropes epinephrine, dopamine and dobutamine on expression of endothelial adhesion molecules and on neutrophil adhesion to endothelial cells under dynamic conditions. Endothelial cells were obtained by collagenase digestion of human umbilical cord veins.Endothelial monolayers were pre-incubated with one of the chosen inotropes, with or without butoxamine, and exposed to interleukin-1. The monolayers were then incubated with fluorescencelabelled anti-human monoclonal antibodies directed against the endothelial adhesion molecules ICAM-1, E-selectin or VCAM-1. Expression of endothelial adhesion molecules was analysed by flow cytometry after pre-incubation of endothelial monolayers with one of the chosen inotropes, with or without butoxamine, and after exposure to interleukin-1. To evaluate the neutrophil adherence, the endothelium was placed on a horizontal shaker-incubator and overlayered with neutrophils. Then, non-adherent neutrophils were removed, and cells were completely dissociated. Finally, neutrophils and endothelial cells were counted by flow cytometry. The expression of E-selectin on endothelium following stimulation with interleukin-1 is attenuated by the inotropes dopamine or dobutamine, but not by epinephrine. The addition of butoxamine does not modify the expression of E-selectin following stimulation with interleukin-1 and pre-incubation with one of the chosen inotropes. The decrease in neutrophil adhesion to endothelium following stimulation with interleukin-1 and addition of inotropes is antagonised by the b-blocker butoxamine. In contrast to the modulation of E-selectin expression on endothelium, the effect of inotropes on neutrophil adhesion to endothelium is regulated by the expression of adhesion molecules on PMNs and mediated by the b-adrenoceptor.
    Injury 10/2010; 41(10):1079-83. · 1.93 Impact Factor
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    ABSTRACT: To evaluate the possible protective effect of sympatholytic medications with respect to neutrophil function, we evaluated the influence of a nonselective beta-blocker medication on the interaction of neutrophils and epinephrine after cardiopulmonary bypass. Therefore, we studied the importance of adrenoceptors for the immunomodulation of neutrophils by catecholamines in vitro. First, we investigated the modulation of neutrophils from healthy volunteers, after stimulation with n-formyl-l-methionyl-l-leucyl-l-phenylalanin (FMLP) in the presence of epinephrine with or without the addition of one of the following adrenergic receptor antagonists: atenolol, butoxamine, pindolol, prazosin, or RS79984. The second part included an investigation of the modulation of neutrophils from patients after operative coronary revascularization with or without extracorporeal circulation after stimulation with FMLP and addition of epinephrine. After loading with anti-CD62l or anti-CD11b antibodies or dihydrorhodamine, the expression of CD62l and CD11b and generation of oxidative free radicals were assessed by flow cytometry. The suppression of oxidative free radical generation, inhibition of CD62l downregulation after stimulation with FMLP, and suppression of CD11b upregulation after FMLP stimulation from epinephrine were all mediated by beta(2)-adrenoceptors. After cardiac surgery with cardiopulmonary bypass, epinephrine inhibited the CD62l downregulation, the suppression of CD11b upregulation, and the generation of oxidative free radicals after FMLP stimulation. The pre-operative administration of beta-blockers abolished the immunomodulatory effects of epinephrine on CD62l and CD11b expression and the generation of oxidative free radicals. The immunomodulatory effects of epinephrine on neutrophils remained unchanged irrespective of cardiopulmonary bypass and could contribute to the detrimental effects of epinephrine after heart surgery. The preoperative administration of nonselective beta-blockers abolished the immunomodulatory effects of epinephrine in vitro and in patients, and it enhanced the immunocompetence of neutrophils in a context of increased catecholamine levels.
    Surgery 12/2009; 147(4):562-74. · 3.37 Impact Factor
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    ABSTRACT: The current debate about the side effects of induction agents, e.g. possible adrenal suppression through etomidate, emphasizes the relevance of choosing the correct induction agent in septic patients. However, cardiovascular depression is still the most prominent adverse effect of these agents, and might be especially hazardous in septic patients presenting with a biventricular cardiac dysfunction--or so-called septic cardiomyopathy. Therefore, we tested the dose-response direct cardiac effects of clinically available induction agents in an isolated septic rat heart model. A polymicrobial sepsis was induced via cecal ligation and single puncture. Hearts (n = 50) were isolated and randomly assigned to five groups, each receiving etomidate, s(+)-ketamine, midazolam, propofol, or methohexitone at concentrations of 1 x 10-8 to 1 x 10-4 M. Left ventricular pressure, contractility and lusitropy, and coronary flow were measured. Cardiac work, myocardial oxygen delivery, oxygen consumption, and percentage of oxygen extraction were calculated. All of the induction agents tested showed a dose-dependent depression of cardiac work. Maximal cardiac work dysfunction occurred in the rank order of s(+)-ketamine (-6%) <etomidate (-17%) <methohexitone (-31%) <midazolam (-38%) <propofol (-50%). In addition, propofol showed a maximum decrease in contractility of -38%, a reduction in lusitropy of -44%, and a direct vasodilator effect by increasing coronary flow by +29%. Overall, this study demonstrates that these tested drugs indeed have differential direct cardiac effects in the isolated septic heart. Propofol showed the most pronounced adverse direct cardiac effects. In contrast, S(+)ketamine showed cardiovascular stability over a wide range of concentrations, and might therefore be a beneficial alternative to etomidate.
    Critical care (London, England) 09/2009; 13(5):R144. · 4.72 Impact Factor
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    ABSTRACT: Our study aimed to determine the role of cyclooxygenase-2 in the release of prostaglandin-(PG)-I2 following mesenteric traction during abdominal surgery. In a prospective double-blind, randomized, placebo-controlled study, 40 patients electively scheduled for non-laparoscopic abdominal surgery, were pretreated with the cyclooxygenase-2 inhibitor parecoxib (n=20) or placebo (n=20). Heart rate, arterial blood pressure, oxygenation ratio and plasma concentrations of the stable PGI2-metabolite 6-keto-PGF1alpha were compared between groups before injection of parecoxib (-40 min), immediately before mesenteric traction (0 min), and 5, 10, and 30 min thereafter. In addition, plasma concentrations of valdecoxib, the active metabolite of the prodrug parecoxib, were determined. Plasma concentrations of 6-keto-PGF1alpha and heart rate increased in both groups after mesenteric traction. There were no significant differences between groups at individual times in heart rate, arterial blood pressure and plasma concentrations of 6-keto-PGF1alpha. Oxygenation ratio decreased after 10 and 30 min following mesenteric traction in the parecoxib group with a significant difference between treatment groups at 10 and 30 min. Plasma concentrations of valdecoxib revealed therapeutic values. Our data indicate that PGI2 release following mesenteric traction is mediated by cyclooxygenase-1.
    European Journal of Pharmacology 06/2006; 536(3):296-300. · 2.59 Impact Factor
  • European Journal of Anaesthesiology - EUR J ANAESTH. 01/2006; 23.
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    ABSTRACT: Extracorporeal life support is a worldwide expanding technology for patients in critical cardiogenic shock. The device is usually attached to the femoral vessels using percutaneous techniques. Despite sufficient extracorporeal circulatory support, an unclear number of patients develop high end-diastolic pressures leading to left ventricular distension and pulmonary edema, and ventricular thrombus formation may evolve. This article discusses the strategies to prevent ventricular distension by conservative, interventional, and surgical means, also illustrated by case presentations.
    ASAIO journal (American Society for Artificial Internal Organs: 1992) 59(6):547-53. · 1.39 Impact Factor