Ralf M. Muellenbach

Prof. Ralf M. Muellenbach

Klinikum Kassel, Kassel, Hesse, Germany

Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 May 2012
Verified
Journal Article
Closed access
RMRalf M. Muellenbach
Ralf M. Muellenbach
MKMarkus Kredel
Markus Kredel
EKEkkehard Kunze
Ekkehard Kunze
PKPeter Kranke
Peter Kranke
JKJulian Kuestermann
Julian Kuestermann
TWThomas Wurmb
Thomas Wurmb
Extracorporeal membrane oxygenation (ECMO) can be used as an "ultima ratio" strategy in multiple injured patients with severe thoracic trauma. However, systemic anticoagulation during ECMO is recommended and thus traumatic brain injury (TBI) and intracranial bleeding are well-accepted contraindications for ECMO therapy. This report describes three cases of prolonged heparin-free venovenous ECMO in multiple injured acute respiratory distress syndrome patients with severe TBI failing conventional mechanical ventilation. : Using this strategy, neither ECMO-associated bleeding nor clotting of the extracorporeal circuit occurred. All patients survived. Based on our experience, we recommend the use of heparin-free ECMO in multiple injured patients with pulmonary failure that is not successfully controlled by lung-protective ventilation even if severe TBI is present. IV, therapeutic study.

9 December 2020 in Acta Anaesthesiologica Scandinavica
Verified
Journal Article
Open access
PDF file
CLChristopher Lotz
Christopher Lotz
RMRalf M. Muellenbach
Ralf M. Muellenbach
PMPatrick Meybohm
Patrick Meybohm
HMHaitham Mutlak
Haitham Mutlak
PLPhilipp M. Lepper
Philipp M. Lepper
CRChristian Reyher
Christian Reyher
Background: Changes in pulmonary hemodynamics and ventilation/perfusion were proposed as hallmarks of Coronavirus disease 2019 (COVID‐19)–induced acute respiratory distress syndrome (ARDS). Inhaled nitric oxide (iNO) may overcome these issues and improve arterial oxygenation.Methods: We retrospectively analyzed arterial oxygenation and pulmonary vasoreactivity in seven COVID‐19 ARDS patients receiving 20 ppm iNO for 15‐30 minutes.Results: The inhalation of NO significantly improved oxygenation. All patients with severe ARDS had higher partial pressures of oxygen and reduced pulmonary vascular resistance. Significant changes in pulmonary shunting were not observed.Conclusion: Overall, iNO could provide immediate help and delay respiratory deterioration in COVID‐19–induced moderate to severe ARDS.

12 June 2007 in Intensive Care Medicine
Verified
Journal Article
Closed access
PDF file
RMRalf M. Muellenbach
Ralf M. Muellenbach
MKMarkus Kredel
Markus Kredel
HSHarun M. Said
Harun M. Said
BKBernd Klosterhalfen
Bernd Klosterhalfen
BZBernd Zollhoefer
Bernd Zollhoefer
JBJörg Brederlau
Jörg Brederlau

2 July 2013 in BMC Pregnancy and Childbirth
Verified
Journal Article
Open access
PDF file
PKPeter Kranke
Peter Kranke
TGThierry Girard
Thierry Girard
PLPatricia Lavand'homme
Patricia Lavand'homme
AMAndrea Melber
Andrea Melber
JJJohanna Jokinen
Johanna Jokinen
AHArnd Hönig
Arnd Hönig
The epidural route is still considered the gold standard for labour analgesia, although it is not without serious consequences when incorrect placement goes unrecognized, e.g. in case of intravascular, intrathecal and subdural placements. Until now there has not been a viable alternative to epidural analgesia especially in view of the neonatal outcome and the need for respiratory support when long-acting opioids are used via the parenteral route. Pethidine and meptazinol are far from ideal having been described as providing rather sedation than analgesia, affecting the cardiotocograph (CTG), causing fetal acidosis and having active metabolites with prolonged half-lives especially in the neonate. Despite these obvious shortcomings, intramuscular and intravenously administered pethidine and comparable substances are still frequently used in delivery units. Since the end of the 90ths remifentanil administered in a patient-controlled mode (PCA) had been reported as a useful alternative for labour analgesia in those women who either don’t want, can’t have or don’t need epidural analgesia. In view of the need for conversion to central neuraxial blocks and the analgesic effect remifentanil has been demonstrated to be superior to pethidine. Despite being less effective in terms of the resulting pain scores, clinical studies suggest that the satisfaction with analgesia may be comparable to that obtained with epidural analgesia. Owing to this fact, remifentanil has gained a place in modern labour analgesia in many institutions. However, the fact that remifentanil may cause harm should not be forgotten when the use of this potent mu-agonist is considered for the use in labouring women. In the setting of one-to-one midwifery care, appropriate monitoring and providing that enough experience exists with this potent opioid and the treatment of potential complications, remifentanil PCA is a useful option in addition to epidural analgesia and other central neuraxial blocks. Already described serious consequences should remind us not refer to remifentanil PCA as a “poor man’s epidural” and to safely administer remifentanil with an appropriate indication. Therefore, the authors conclude that economic considerations and potential cost-savings in conjunction with remifentanil PCA may not be appropriate main endpoints when studying this valuable method for labour analgesia.

25 July 2013 in Perfusion
Verified
Journal Article
Closed access
RMRalf M. Muellenbach
Ralf M. Muellenbach
CKC Kilgenstein
C Kilgenstein
PKP Kranke
P Kranke
JKJ Küstermann
J Küstermann
MKM Kredel
M Kredel
TWT Westermaier
T Westermaier
Extracorporeal membrane oxygenation (ECMO) is increasingly used in ARDS patients with hypoxemia and/or severe hypercapnia refractory to conventional treatment strategies. However, it is associated with severe intracranial complications, e.g. ischemic or hemorrhagic stroke. The arterial carbon dioxide partial pressure (PaCO2) is one of the main determinants influencing cerebral blood flow and oxygenation. Since CO2 removal is highly effective during ECMO, reduction of CO2 may lead to alterations in cerebral perfusion. We report on the variations of cerebral oxygenation during the initiation period of ECMO treatment in a patient with hypercapnic ARDS, which may partly explain the findings of ischemic and/or hemorrhagic complications in conjunction with ECMO.

29 January 2007 in Critical Care
Verified
Journal Article
Open access
MKMarkus Kredel
Markus Kredel
RMRalf M. Muellenbach
Ralf M. Muellenbach
RBRobert W Brock
Robert W Brock
HWHans-Hinrich Wilckens
Hans-Hinrich Wilckens
JBJoerg Brederlau
Joerg Brederlau
CWChristian Wunder
Christian Wunder
Introduction: Consequences of lung recruitment with prolonged high positive end-expiratory pressure (PEEP) ventilation for liver function are unclear. We therefore investigated liver dysfunction during two different ventilation treatment regimens of experimental acute respiratory distress syndrome. Methods: Sixteen anaesthetised juvenile pietrain pigs were ventilated in the pressure-controlled mode (PCV) with an inspiratory fraction of oxygen (FiO2) of 1.0, a respiratory frequency of 30 per minute, a tidal volume of 6 ml/kg, and a PEEP of 5 cm H2O. After lung injury was induced by repeated pulmonary lavage with normal saline, animals were randomly assigned into two groups (n = 8 each) for a 24-hour trial: PCV (unchanged ventilation) and PCV with recruitment (PCV+R) (starting with a sustained inflation of 50 cm H2O for 1 minute, the ventilation was continued while increasing PEEP in increments of 3 cm H2O every 15 minutes as long as arterial oxygen tension [PaO2] improved). After recruitment, FiO2 was reduced to 0.4 and the PEEP was lowered every 15 minutes until PaO2 decreased to 12.0 to 14.7 kPa (90 to 110 torr). Serum levels of hyaluronic acid (HA), routine liver serum markers, and plasma disappearance rate of indocyanine green (ICG) were tested before and after lung injury, and 6 and 18 hours after randomisation. Liver serum markers were also tested at 24 hours. Paraffin sections of liver tissue stained by haematoxylin and eosin were made after euthanisation. Results: The PCV+R group exhibited more polymorphonuclear neutrophils and lymphocytes in the liver sinusoids: median score (interquartile range) of 1.5 (1.4 to 1.5) compared to 0.9 (0.7 to 1.1) (p = 0.01). Elevation of bilirubin, aspartate aminotransferase, and lactate dehydrogenase was more prominent in the PCV+R group. Plasma disappearance rate of ICG indicated no liver dysfunction. HA levels in the PCV+R group gradually increased and were significantly higher (p < 0.001) at 6 and 18 hours with 59 (57 to 64) and 75 (66 to 84) ng/ml, respectively, than in the PCV group with 34 (32 to 48) and 41 (38 to 42) ng/ml, respectively. Conclusion: The PCV+R group showed a more prominent inflammatory reaction in their liver sinusoids accompanied by increased serum levels of liver enzymes and HA. Therefore, recruitment with higher PEEP levels for treatment of respiratory failure might lead to liver dysfunction.