Hemoadsorption therapy for myoglobin removal in rhabdomyolysis: consensus of the hemoadsorption in rhabdomyolysis task force.

BACKGROUND: Rhabdomyolysis describes a syndrome characterized by muscle necrosis and the subsequent release of creatine kinase and myoglobin into the circulation. Myoglobin elimination with extracorporeal hemoadsorption has been shown to effectively remove myoglobin from the circulation. Our aim was to provide best practice consensus statements developed by the Hemoadsorption in Rhabdomyolysis Task Force (HRTF) regarding the use of hemadsorption for myoglobin elimination. METHODS: A systematic literature search was performed until 11th of January 2023, after which the Rhabdomyolysis RTF was assembled comprising international experts from 6 European countries. Online conferences were held between 18th April - 4th September 2023, during which 37 consensus questions were formulated and using the Delphi process, HRTF members voted online on an anonymised platform. In cases of 75 to 90% agreement a second round of voting was performed. RESULTS: Using the Delphi process on the 37 questions, strong consensus (> 90% agreement) was achieved in 12, consensus (75 to 90% agreement) in 10, majority (50 to 74%) agreement in 13 and no consensus (< 50% agreement) in 2 cases. The HRTF formulated the following recommendations: (1) Myoglobin contributes to the development of acute kidney injury; (2) Patients with myoglobin levels of > 10,000 ng/ml should be considered for extracorporeal myoglobin removal by hemoadsorption; (3) Hemoadsorption should ideally be started within 24 h of admission; (4) If myoglobin cannot be measured then hemoadsorption may be indicated based on clinical picture and creatinine kinase levels; (5) Cartridges should be replaced every 8-12 h until myoglobin levels < 10,000 ng/ml; (6) In patients with acute kidney injury, hemoadsorption can be discontinued before dialysis is terminated and should be maintained until the myoglobin concentration values are consistently < 5000 ng/ml. CONCLUSIONS: The current consensus of the HRTF support that adjuvant hemoadsorption therapy in severe rhabdomyolysis is both feasible and safe and may be an effective method to reduce elevated circulating levels of myoglobin.

Elevation of neutrophil-derived factors in patients after multiple trauma.

Trauma represents one of the leading causes of death worldwide. Traumatic injuries elicit a dynamic inflammatory response with systemic release of inflammatory cytokines. Disbalance of this response can lead to systemic inflammatory response syndrome or compensatory anti-inflammatory response syndrome. As neutrophils play a major role in innate immune defence and are crucial in the injury-induced immunological response, we aimed to investigate systemic neutrophil-derived immunomodulators in trauma patients. Therefore, serum levels of neutrophil elastase (NE), myeloperoxidase (MPO) and citrullinated histone H3 (CitH3) were quantified in patients with injury severity scores above 15. Additionally, leukocyte, platelet, fibrinogen and CRP levels were assessed. Lastly, we analysed the association of neutrophil-derived factors with clinical severity scoring systems. Although the release of MPO, NE and CitH3 was not predictive of mortality, we found a remarkable increase in MPO and NE in trauma patients as compared with healthy controls. We also found significantly increased levels of MPO and NE on Days 1 and 5 after initial trauma in critically injured patients. Taken together, our data suggest a role for neutrophil activation in trauma. Targeting exacerbated neutrophil activation might represent a new therapeutic option for critically injured patients.

Elevated EMMPRIN Serum Levels Indicate Plaque Vulnerability in Patients With Asymptomatic High Grade Carotid Stenosis.

OBJECTIVE: Carotid atherosclerosis is an important cause of cerebral ischaemic stroke. Sonographic plaque characteristics are inappropriate for exact prediction of possible future ischaemic events. Additional markers are needed to predict the clinical outcome in high grade carotid stenosis. This study aimed to test extracellular matrix metalloproteinase inducer (EMMPRIN), due to its involvement in plaque formation and destabilisation, as a potential marker of high risk vulnerable plaques. METHODS: EMMPRIN was analysed in pre-operative serum samples from patients with symptomatic and asymptomatic carotid artery stenosis by a specific ELISA. Pre-operative duplex sonography classified the atherosclerotic plaque due to echogenicity. Histopathological analysis of vulnerable and non-vulnerable plaques was based on the American Heart Association (AHA) classification. RESULTS: The study included 265 patients undergoing carotid endarterectomy: 90 (m:f, 69:21) patients with symptomatic and 175 (m:f, 118:57) with asymptomatic disease. Analysis of circulating EMMPRIN revealed significantly higher levels in patients with echolucent plaques (4 480; IQR 3 745, 6 144 pg/mL) compared with echogenic plaques (4 159; IQR 3 418, 5 402 pg/mL; p = .025). Asymptomatic patients with vulnerable plaques had significantly higher levels of EMMPRIN (4 875; IQR 3 850, 7 016 pg/mL) compared with non-vulnerable plaques (4 109; IQR 3 433, 5 402 pg/mL; p < .001). In logistic regression analysis, duplex sonography combined with age, gender, and clinical risk factors predicted vulnerable plaques in asymptomatic patients with an AUC of 0.71 (95% CI 0.61 - 0.80). EMMPRIN significantly improved the AUC in asymptomatic patients (AUC 0.79; 95% CI 0.71 - 0.87; p = .014). CONCLUSION: Patients with high risk plaques according to ultrasound and histopathological characteristics demonstrated increased serum EMMPRIN levels. EMMPRIN on top of clinical risk factors, including age, gender, and duplex sonography may be used for pre-operative risk stratification in asymptomatic patients.

Clinical relevance of lung transplantation for COVID-19 ARDS: a nationwide study.

BACKGROUND: Although the number of lung transplantations (LTx) performed worldwide for COVID-19 induced acute respiratory distress syndrome (ARDS) is still low, there is general agreement that this treatment can save a subgroup of most severly ill patients with irreversible lung damage. However, the true proportion of patients eligible for LTx, the overall outcome and the impact of LTx to the pandemic are unknown. METHODS: A retrospective analysis was performed using a nationwide registry of hospitalised patients with confirmed severe acute respiratory syndrome coronavirus type 2 (SARS-Cov-2) infection admitted between January 1, 2020 and May 30, 2021 in Austria. Patients referred to one of the two Austrian LTx centers were analyzed and grouped into patients accepted and rejected for LTx. Detailed outcome analysis was performed for all patients who received a LTx for post-COVID-19 ARDS and compared to patients who underwent LTx for other indications. RESULTS: Between January 1, 2020 and May 30, 2021, 39.485 patients were hospitalised for COVID-19 in Austria. 2323 required mechanical ventilation, 183 received extra-corporeal membrane oxygenation (ECMO) support. 106 patients with severe COVID-19 ARDS were referred for LTx. Of these, 19 (18%) underwent LTx. 30-day mortality after LTx was 0% for COVID-19 ARDS transplant recipients. With a median follow-up of 134 (47-450) days, 14/19 patients are alive. CONCLUSIONS: Early referral of ECMO patients to a LTx center is pivotal in order to select patients eligible for LTx. Transplantation offers excellent midterm outcomes and should be incorporated in the treatment algorithm of post-COVID-19 ARDS.

What is the optimal anesthetic monitoring regarding immediate and short-term outcomes after liver transplantation?-A systematic review of the literature and expert panel recommendations.

BACKGROUND: Liver transplant centers vary in approach to intraoperative vascular accesses, monitoring of cardiac function and temperature management. Evidence is limited regarding impact of selected modalities on postoperative outcomes. OBJECTIVES: To review the literature and provide expert panel recommendations on optimal intraoperative arterial blood pressure (BP), central venous pressure (CVP), and vascular accesses, monitoring of cardiac function and intraoperative temperature management regarding immediate and short-term outcomes after orthotopic liver transplant (OLT). METHODS: Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel. Recommendations made for: (1) Vascular accesses, arterial BP and CVP monitoring, (2) cardiac function monitoring, and (3) Intraoperative temperature management (CRD42021239908). RESULTS: Of 2619 articles screened 16 were included. Studies were small, retrospective, and observational. Vascular access studies demonstrated low rates of insertion complications. TEE studies demonstrated low rates of esophageal hemorrhage. One study found lower hospital-LOS and 30-day mortality in patients monitored with both PAC and TEE. Other monitoring studies were heterogenous in design and outcomes. Temperature studies showed increased blood transfusion and ventilation times in hypothermic groups. CONCLUSIONS: Recommendations were made for; routine arterial and CVP monitoring as a minimum standard of practice, consideration of discrepancy between peripheral and central arterial BP in patients with hemodynamic instability and high vasopressor requirements, and routine use of high flow cannulae while monitoring for extravasation and hematoma formation. Availability and expertise in PAC and/or TEE monitoring is strongly recommended particularly in hemodynamic instability, portopulmonary HT and/or cardiac dysfunction. TEE use is recommended as an acceptable risk in patients with treated esophageal varices and is an effective diagnostic tool for emergency cardiovascular collapse. Maintenance of intraoperative normothermia is strongly recommended.

Urinary [TIMP-2] × [IGFBP-7] for predicting acute kidney injury in patients undergoing orthotopic liver transplantation.

BACKGROUND: The product of the concentrations of urinary tissue inhibitor of metalloproteinases-2 and insulin-like growth factor binding protein-7 (urinary [TIMP-2] × [IGFBP-7]) has been suggested as biomarker for early detection of acute kidney injury (AKI) in various clinical settings. However, the performance of urinary [TIMP-2] × [IGFBP-7] to predict AKI has never been assessed in patients undergoing orthotopic liver transplantation (OLT). Thus, the aim of this study was to assess the early predictive value of urinary [TIMP-2] × [IGFBP-7] for the development of AKI after OLT. METHODS: In this observational study, urinary [TIMP-2] × [IGFBP-7] was measured in samples from adult OLT patients. AKI was diagnosed and classified according to KDIGO criteria. Areas under the receiver operating curves (AUC) were calculated to assess predictive values of urinary [TIMP-2] × [IGFBP-7] for the development of AKI. RESULTS: Forty patients (mean age 55 ± 8 years) were included. Twenty-eight patients (70%) developed AKI stage 1, 2, or 3 within 48 h after OLT. Urinary [TIMP-2] × [IGFBP-7] was not predictive for AKI at the end of OLT (AUC: 0.54, CI [0.32-0.75], P = 0.72), at day 1 (AUC: 0.60, CI [0.41-0.79], P = 0.31), or day 2 after OLT (AUC: 0.63, CI [0.46-0.8], P = 0.18). CONCLUSION: Based on our results, routine clinical use of urinary [TIMP-2] × [IGFBP-7] cannot be recommended for risk assessment of AKI in patients undergoing OLT.

Increased serum concentrations of soluble ST2 predict mortality after burn injury.

BACKGROUND: Large burn injuries induce a systemic response in affected patients. Soluble ST2 (sST2) acts as a decoy receptor for interleukin-33 (IL-33) and has immunosuppressive effects. sST2 has been described previously as a prognostic serum marker. Our aim was to evaluate serum concentrations of sST2 and IL-33 after thermal injury and elucidate whether sST2 is associated with mortality in these patients. METHODS: We included 32 burn patients (total body surface area [TBSA] >10%) admitted to our burn intensive care unit and compared them to eight healthy probands. Serum concentrations of sST2 and IL-33 were measured serially using an enzyme-linked immunosorbent assay (ELISA) technique. RESULTS: The mean TBSA was 32.5%±19.6%. Six patients (18.8%) died during the hospital stay. Serum analyses showed significantly increased concentrations of sST2 and reduced concentrations of IL-33 in burn patients compared to healthy controls. In our study cohort, higher serum concentrations of sST2 were a strong independent predictor of mortality. CONCLUSIONS: Burn injuries cause an increment of sST2 serum concentrations with a concomitant reduction of IL-33. Higher concentrations of sST2 are associated with increased in-hospital mortality in burn patients.

Impact of a remifentanil supply shortage on mechanical ventilation in a tertiary care hospital: a retrospective comparison.

BACKGROUND: The continuous administration of opioids in critical care patients is a common therapy for the tolerance of mechanical ventilation. Opioid choice has a crucial impact on the length of mechanical ventilation. Owing to its very short context-sensitive half-life, remifentanil widens the available options for sedoanalgetic strategies. Supply disruption of such established intensive care medication has been reported to worsen clinical outcomes. METHODS: This retrospective study investigated the influence of a nationwide supply shortage of remifentanil on mechanical ventilation and ventilation-associated outcomes at three perioperative intensive care units (ICUs) in a tertiary care hospital in Vienna. Two groups were followed: patients admitted to the ICU during the remifentanil shortage (July 1, 2016 to September 30, 2016) and a control group one year after the remifentanil shortage (July 1, 2017 to September 30, 2017). Included patients were adults, received mechanical ventilation for at least 6 h, were admitted less than 90 days in the respective ICU, and survived their admission. RESULTS: For comparison, Poisson count regression models and logistic regression models were computed. To compensate for multiple testing, the significance level was split (0.02 for the primary and 0.006 for secondary outcome parameters). Patients in the remifentanil shortage group received significantly longer mechanical ventilation (risk ratio 2.19, 95% confidence interval 2.14-2.24, P <0.001) with significantly prolonged ICU stay (P <0.001), days with non-invasive ventilation (P <0.001), and length of hospital stay (P <0.001). No significant difference was found in the occurrence of pneumonia (P = 0.040) and sepsis (P = 0.061). A greater proportion of patients in the shortage group underwent secondary tracheostomy (P <0.001). CONCLUSIONS: The remifentanil shortage caused a significant impairment of essential outcome parameters in the ICU.

Graft-derived macrophage migration inhibitory factor correlates with hepatocellular injury in patients undergoing liver transplantation.

Experimental studies suggest that macrophage migration inhibitory factor (MIF) mediates ischemia/reperfusion injury during liver transplantation. This study assessed whether human liver grafts release MIF during preservation, and whether the release of MIF is proportional to the extent of hepatocellular injury. Additionally, the association between MIF and early allograft dysfunction (EAD) after liver transplantation was evaluated. Concentrations of MIF, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and creatine kinase (CK) were measured in effluents of 38 liver grafts, and in serum of recipients. Concentrations of MIF in the effluent were greater than those in the recipients' serum before and after reperfusion (58 [interquartile range, IQR:23-79] µg/mL vs 0.06 [IQR:0.03-0.07] µg/mL and 1.3 [IQR:0.7-1.8] µg/mL, respectively; both P<.001). Effluent MIF concentrations correlated with effluent concentrations of the cell injury markers ALT (R=.51, P<.01), AST (R=.51, P<.01), CK (R=.45, P=.01), and LDH (R=.56, P<.01). Patients who developed EAD had greater MIF concentrations in effluent and serum 10 minutes after reperfusion than patients without EAD (Effluent: 80 [IQR:63-118] µg/mL vs 36 [IQR:20-70] µg/mL, P=.02; Serum: 1.7 [IQR:1.2-2.5] µg/mL vs 1.1 [IQR:0.6-1.7] µg/mL, P<.001). CONCLUSION: Human liver grafts release MIF in proportion to hepatocellular injury. Greater MIF concentrations in effluent and recipient's serum are associated with EAD after liver transplantation.

A randomized placebo-controlled phase II study of a Pseudomonas vaccine in ventilated ICU patients.

BACKGROUND: Currently, no vaccine against Pseudomonas is available. IC43 is a new, recombinant, protein (OprF/I)-based vaccine against the opportunistic pathogen, Pseudomonas aeruginosa, a major cause of serious hospital-acquired infections. IC43 has proven immunogenicity and tolerability in healthy volunteers, patients with burns, and patients with chronic lung diseases. In order to assess the immunogenicity and safety of IC43 in patients who are most at risk of acquiring Pseudomonas infections, it was evaluated in mechanically ventilated ICU patients. METHODS: We conducted a randomized, placebo-controlled, partially blinded study in mechanically ventilated ICU patients. The immunogenicity of IC43 at day 14 was determined as the primary endpoint, and safety, efficacy against P. aeruginosa infections, and all-cause mortality were evaluated as secondary endpoints. Vaccinations (100 µg or 200 µg IC43 with adjuvant, or 100 µg IC43 without adjuvant, or placebo) were given twice in a 7-day interval and patients were followed up for 90 days. RESULTS: Higher OprF/I IgG antibody titers were seen at day 14 for all IC43 groups versus placebo (P < 0.0001). Seroconversion (≥4-fold increase in OprF/I IgG titer from days 0 to 14) was highest with 100 µg IC43 without adjuvant (80.6%). There were no significant differences in P. aeruginosa infection rates, with a low rate of invasive infections (pneumonia or bacteremia) in the IC43 groups (11.2-14.0%). Serious adverse events (SAEs) considered possibly related to therapy were reported by 2 patients (1.9%) in the group of 100 µg IC43 with adjuvant. Both SAEs resolved and no deaths were related to study treatment. Local tolerability symptoms were mild and rare (<5% of patients), a low rate of treatment-related treatment-emergent adverse events (3.1-10.6%) was observed in the IC43 groups. CONCLUSION: This phase II study has shown that IC43 vaccination of ventilated ICU patients produced a significant immunogenic effect. P. aeruginosa infection rates did not differ significantly between groups. In the absence of any difference in immune response following administration of 100 µg IC43 without adjuvant compared with 200 µg IC43 with adjuvant, the 100 µg dose without adjuvant was considered for further testing of its possible benefit of improved outcomes. There were no safety or mortality concerns. TRIAL REGISTRATION: ClinicalTrials.gov, NCT00876252 . Registered on 3 April 2009.

Plasma levels of chemokine ligand 20 and chemokine receptor 6 in patients with sepsis: A case control study.

BACKGROUND: Chemokine ligand 20 (CCL20) is a chemokine released by mainly liver and blood leucocytes. Particularly under pro-inflammatory circumstances it triggers chemotaxis of lymphocytes and dendritic cells via activating receptor chemokine receptor 6 (CCR6) that is specific to it. In experimental sepsis models, the chemokine-receptor pair has been identified as a potential pathophysiological axis affecting mortality. OBJECTIVE: Measurement of CCL20 and CCR6 plasma levels in septic patients compared with postsurgical, nonseptic patients. DESIGN: Case control study. SETTING: Surgical ICUs of the Department of Anaesthesiology, General Hospital of Vienna, Vienna, Austria. PATIENTS: Plasma levels were measured in 46 patients with sepsis, severe sepsis or septic shock according to current American College of Chest Physicians/Society of Critical Care Medicine criteria at the day of sepsis onset. Plasma levels in 36 postsurgical controls without sepsis admitted to the ICU were investigated. Plasma concentrations were determined by using commercially available ELISA kits. Data are given as median and interquartile range (IQR). MAIN OUTCOME MEASURES: CCL20 and CCR6 plasma levels. RESULTS: CCL20 plasma levels were significantly increased in the sepsis group: 220.9 pg ml (IQR, 72.8 to 540.1) compared with the ICU controls: 37.0 pg ml (IQR 6.5 to 83.6) (P < 0.0001). Significantly elevated CCR6 levels were found in the sepsis group: 2.47 ng ml (IQR 0.92 to 5.54) compared with the controls: 0.59 ng ml (IQR 0.17 to 1.48) (P < 0.0001). Both CCL20 and CCR6 correlated with the maximum sequential organ failure assessment score (CCL20: P < 0.0001, CCR6: P < 0.0001). Length of ICU admission depended significantly on the logarithm of CCR6 (P = 0.008) and sequential organ failure assessment maximum (P < 0.0001). CONCLUSION: There were early increased plasma concentrations of CCL20 and CCR6 in patients with sepsis. CCL20 and CCR6 correlate with severity of illness in ICU patients. Levels of CCR6 predicted the length of patients' admission.

Macrophage migration inhibitory factor as a potential predictor for requirement of renal replacement therapy after orthotopic liver transplantation.

Acute kidney injury (AKI) after orthotopic liver transplantation (OLT) is associated with a poor clinical outcome. Because there is no specific treatment for postoperative AKI, early recognition and prevention are fundamental therapeutic approaches. Concentrations of the proinflammatory cytokine macrophage migration inhibitory factor (MIF) are elevated in patients with kidney disease. We hypothesized that plasma MIF concentrations would be greater in patients developing AKI after OLT compared with patients with normal kidney function. Twenty-eight patients undergoing OLT were included in the study. Kidney injury was classified according to AKI network criteria. Fifteen patients (54%) developed severe AKI after OLT, 11 (39%) requiring renal replacement therapy (RRT). On the first postoperative day, patients with severe AKI had greater plasma MIF concentrations (237 ± 123 ng/mL) than patients without AKI (95 ± 63 ng/mL; P < 0.001). The area under the receiver operating characteristic (ROC) curve for predicting severe AKI was 0.87 [95% confidence interval (CI), 0.69-0.97] for plasma MIF, 0.61 (95% CI, 0.40-0.79) for serum creatinine (sCr), and 0.90 (95% CI, 0.72-0.98) for delta serum creatinine (ΔsCr). Plasma MIF (P = 0.02) and ΔsCr (P = 0.01) yielded a better predictive value than sCr for the development of severe AKI. Furthermore, the area under the ROC curve to predict the requirement of RRT was 0.87 (95% CI, 0.68-0.96) for plasma MIF, 0.65 (95% CI, 0.44-0.82) for sCr, and 0.72 (95% CI, 0.52-0.88) for ΔsCr. Plasma MIF had a better predictive value than sCr for the requirement of RRT (P = 0.02). In conclusion, postoperative plasma MIF concentrations were elevated in patients who developed severe AKI after OLT. Furthermore, plasma MIF concentrations showed a good prognostic value for identifying patients developing severe AKI or requiring postoperative RRT after OLT.

Extracorporeal CO2 removal as bridge to lung transplantation in life-threatening hypercapnia.

In patients awaiting lung transplantation (LTX), adequate gas exchange may not be sufficiently achieved by mechanical ventilation alone if acute respiratory decompensation arises. We report on 20 patients with life-threatening hypercapnia who received extracorporeal CO2 removal (ECCO2-R) by means of the interventional lung assist (ILA®, Novalung) as bridge to LTX. The most common underlying diagnoses were bronchiolitis obliterans syndrome, cystic fibrosis, and idiopathic pulmonary fibrosis, respectively. The type of ILA was pumpless arteriovenous or pump-driven venovenous (ILA activve®, Novalung) in 10 patients each. ILA bridging was initiated in 15 invasively ventilated and five noninvasively ventilated patients, of whom one had to be intubated prior to LTX. Hypercapnia and acidosis were effectively corrected in all patients within the first 12 h of ILA therapy: PaCO2 declined from 109 (70-146) to 57 (45-64) mmHg, P < 0.0001; pH increased from 7.20 (7.06-7.28) to 7.39 (7.35-7.49), P < 0.0001. Four patients were switched to extracorporeal membrane oxygenation due to progressive hypoxia or circulatory failure. Nineteen patients (95%) were successfully transplanted. Hospital and 1-year survival was 75 and 72%, respectively. Bridging to LTX with ECCO2-R delivered by arteriovenous pumpless or venovenous pump-driven ILA is feasible and associated with high transplantation and survival rates.

Circulating monocyte populations as biomarker for abdominal aortic aneurysms: a single-center retrospective cohort study.

Background: Abdominal aortic aneurysm (AAA) development is driven by inflammation, in particular myeloid cells, which represent attractive biomarker candidates. Yet to date, the maximum aortic diameter is the only clinically applied predictor of AAA progression and indicator for surgical repair. We postulated that aortic inflammation is reflected in a systemic change of monocyte populations, which we investigated regarding marker potential in AAA diagnosis and prognosis. Methods: We conducted a single-center retrospective cohort study in a diagnostic setting, measuring monocyte subsets by flow cytometry in peripheral blood samples of 47 AAA patients under surveillance, matched with 25 healthy controls and 25 patients with peripheral artery disease (PAD). In a prognostic setting, we acquired longitudinal data of 60 AAA patients including aneurysm growth assessment by computed tomography at 6-month intervals. Results: Blood levels of total monocytes, CD16+ monocytes and particularly intermediate monocytes were significantly increased in AAA patients versus healthy individuals and were also elevated compared to PAD patients. The combination of intermediate monocyte and D-dimer blood levels outperformed the individual diagnostic marker values. Additionally, the elevated concentrations of total monocytes, intermediate monocytes, and monocyte-platelet aggregates (MPA) were suited to predict rapid AAA progression over short-term periods of six months. Of note, MPA were identified as independent predictor of AAA disease progression in multivariable analysis. Conclusion: Circulating monocyte subsets are elevated in AAA patients and support diagnosis and prediction of aneurysm progression. Monocyte subsets and D-dimer reflect different hallmarks (inflammation and hemostasis) of AAA pathology and when combined, may serve as improved biomarker.

Extracorporeal liver support.

PURPOSE OF REVIEW: The mortality in patients suffering from liver failure decreased in line with medical progress over the past decades. However, it still remains unacceptably high and liver transplantation still provides the only definite treatment for many patients. The goal of extracorporeal liver support systems is to improve the clinical condition of patients waiting for liver transplantation and/or enhance the regeneration of native injured liver. Nonbiological liver support systems with pure detoxification and biological liver support systems with assumed synthesis and metabolism in addition to detoxification are currently under clinical investigation. Since patient survival is the most significant outcome parameter, we focus in this review on prospective randomized trials with survival rate as primary outcome parameter. RECENT FINDINGS: Although a short-term outcome benefit in patients with acute-on-chronic liver failure was shown in some of these trials, long-term outcome has not been improved significantly with either of the support systems. In spite of more favourable but yet limited data in patients with acute liver failure, it is too early to draw definite conclusions. SUMMARY: The future development of liver support systems may provide different combinations of new adsorbents, integrated regional citrate anticoagulation and eventual substitution of irreversibly damaged albumin.

[Definitions, decision-making and documentation in end of life situations in the intensive care unit]. / Therapiezieländerungen auf der Intensivstation - Definitionen, Entscheidungsfindung und Dokumentation.

The present work provides assistance for physicians concerning decision making in clinical borderline situations in the ICU. Based on a structured checklist the two fundamental aspects of any medical decision, the medical indication and the patient's preference are queried in a systematic way. Four possible steps of withholding and/or withdrawing therapy are discussed. Finally, recommendations regarding appropriate documentation of end of life decisions are provided.

Randomized controlled study to evaluate the safety and clinical impact of percutaneous auricular vagus nerve stimulation in patients with severe COVID-19.

Introduction: A severe course of COVID-19 is characterized by a hyperinflammatory state resulting in acute respiratory distress syndrome or even multi-organ failure along a derailed sympatho-vagal balance. Methods: In this prospective, randomized study, we evaluate the hypothesis that percutaneous minimally invasive auricular vagus nerve stimulation (aVNS) is a safe procedure and might reduce the rate of clinical complications in patients with severe course of COVID-19. In our study, patients with SARS-CoV-2 infection admitted to the intensive care unit with moderate-to-severe acute respiratory distress syndrome, however without invasive ventilation yet, were included and following randomization assigned to a group receiving aVNS four times per 24 h for 3 h and a group receiving standard of care (SOC). Results: A total of 12 patients were included (six in the aVNS and six in the SOC group). No side effects in aVNS were reported, especially no significant pain at device placement or during stimulation at the stimulation site or significant headache or bleeding after or during device placement or lasting skin irritation. There was no significant difference in the aVNS and SOC groups between the length of stay in the intensive care unit and at the hospital, bradycardia, delirium, or 90-day mortality. In the SOC group, five of six patients required invasive mechanical ventilation during their stay at hospital and 60% of them venovenous extracorporeal membrane oxygenation, compared to three of six patients and 0% in the aVNS group (p = 0.545 and p = 0.061). Discussion: Vagus nerve stimulation in patients with severe COVID-19 is a safe and feasible method. Our data showed a trend to a reduction of progression to the need of invasive ventilation and venovenous extracorporeal membrane oxygenation which encourages further research with larger patient samples.

Regional citrate anticoagulation in patients with liver failure supported by a molecular adsorbent recirculating system.

OBJECTIVE: Regional citrate anticoagulation has emerged as a promising method in critically ill patients at high risk of bleeding. However, in patients with liver failure, citrate accumulation may lead to acid-base and electrolyte imbalances, notably of calcium. The aim of this study was to evaluate the feasibility and safety of regional citrate anticoagulation during liver support using a molecular adsorbent recirculating system as well as its effects on electrolyte and acid-base balance in patients with liver failure. DESIGN: Prospective observational study. SETTING: University hospital. PATIENTS: Twenty critically ill patients supported by molecular adsorbent recirculating system resulting from liver failure between January 2007 and May 2009. MEASUREMENTS AND MAIN RESULTS: The median duration of molecular adsorbent recirculating system treatment was 20 hrs (interquartile range, 18-22 hrs). Two of 77 molecular adsorbent recirculating system treatments (2%) were prematurely discontinued as a result of filter clotting and bleeding, respectively. The median citrate infusion rate, necessary to maintain the postfilter ionized calcium between 0.2 and 0.4 mmol/L, was 3.1 mmol/L (interquartile range, 2.3-4 mmol/L) blood flow. The median calcium chloride substitution rate was 0.9 mmol/L (0.3-1.7 mmol/L) dialysate. Total serum calcium remained stable during molecular adsorbent recirculating system treatments. There was a statistically significant increase of the ratio of total calcium to systemic ionized calcium (2.04 ± 0.32 mmol/L to 2.17 ± 0.35; p = .01), which reflected citrate accumulation resulting from liver failure. Under close monitoring, no clinically relevant electrolytes or acid-base disorders were observed. CONCLUSIONS: Our results suggest that regional citrate anticoagulation is a safe and feasible method to maintain adequate circuit lifespan without increasing the risk of hemorrhagic complications while maintaining a normal acid-base as well as electrolyte balance in patients with liver failure supported by molecular adsorbent recirculating system.

Suitable CO2 Solubility Models for Determination of the CO2 Removal Performance of Oxygenators.

CO2 removal via membrane oxygenators during lung protective ventilation has become a reliable clinical technique. For further optimization of oxygenators, accurate prediction of the CO2 removal rate is necessary. It can either be determined by measuring the CO2 content in the exhaust gas of the oxygenator (sweep flow-based) or using blood gas analyzer data and a CO2 solubility model (blood-based). In this study, we determined the CO2 removal rate of a prototype oxygenator utilizing both methods in in vitro trials with bovine and in vivo trials with porcine blood. While the sweep flow-based method is reliably accurate, the blood-based method depends on the accuracy of the solubility model. In this work, we quantified performances of four different solubility models by calculating the deviation of the CO2 removal rates determined by both methods. Obtained data suggest that the simplest model (Loeppky) performs better than the more complex ones (May, Siggaard-Anderson, and Zierenberg). The models of May, Siggaard-Anderson, and Zierenberg show a significantly better performance for in vitro bovine blood data than for in vivo porcine blood data. Furthermore, the suitability of the Loeppky model parameters for bovine blood (in vitro) and porcine blood (in vivo) is evaluated.