Performance of sufficient cardiopulmonary resuscitation (CPR) by medical personnel is critical to improve outcomes during cardiac arrest. It has however been shown that even health care professionals possess a lack of knowledge and skills in CPR performance. The optimal method for teaching CPR remains unclear, and data that compares traditional CPR instructional methods with newer modalities of CPR instruction are needed. We therefore conducted a single blinded, randomised study involving medical students in order to evaluate the short- and long-term effects of a classical CPR education compared with a bilateral approach to CPR training, consisting of problem-based learning (PBL) plus high fidelity simulation. One hundred twelve medical students were randomized during a curricular anaesthesiology course to a control (n = 54) and an intervention (n = 58) group. All participants were blinded to group assignment and partook in a 30-min-lecture on CPR basics. Subsequently, the control group participated in a 90-min tutor-guided CPR hands-on-training. The intervention group took part in a 45-min theoretical PBL module followed by 45 min of high fidelity simulated CPR training. The rate of participants recognizing clinical cardiac arrest followed by sufficiently performed CPR was the primary outcome parameter of this study. CPR performance was evaluated after the intervention. In addition, a follow-up evaluation was conducted after 6 months. 51.9% of the intervention group met the criteria of sufficiently performed CPR as compared to only 12.5% in the control group on the day of the intervention (p = 0.007). Hands-off-time as a marker for CPR continuity was significantly less in the intervention group (24.0%) as compared to the control group (28.3%, p = 0.007, Hedges’ g = 1.55). At the six-month follow-up, hands-off-time was still significantly lower in the intervention group (23.7% vs. control group: 31.0%, p = 0.006, Hedges’ g = 1.88) but no significant difference in sufficiently performed CPR was detected (intervention group: 71.4% vs. control group: 54.5%, p = 0.55). PBL combined with high fidelity simulation training leads to a measurable short-term increase in initiating sufficient CPR by medical students immediately after training as compared to classical education. At six month post instruction, these differences remained only partially.

It is known that the use of a cardiopulmonary bypass (CPB) during cardiac surgery leads to leukocyte activation and may, among other causes, induce organ dysfunction due to increased leukocyte recruitment into different organs. Leukocyte extravasation occurs in a cascade-like fashion, including capturing, rolling, adhesion, and transmigration. However, the molecular mechanisms of increased leukocyte recruitment caused by CPB are not known. This clinical study was undertaken in order to investigate which steps of the leukocyte recruitment cascade are affected by the systemic inflammation during CPB. We investigated the effects of CPB on the different steps of the leukocyte recruitment cascade in whole blood from healthy volunteers (n = 9) and patients undergoing cardiac surgery with the use of cardiopulmonary bypass (n = 7) or in off-pump coronary artery bypass-technique (OPCAB, n = 9) by using flow chamber experiments, transmigration assays, and biochemical analysis. CPB abrogated selectin-induced slow leukocyte rolling on E-selectin/ICAM-1 and P-selectin/ICAM-1. In contrast, chemokine-induced arrest and transmigration was significantly increased by CPB. Mechanistically, the abolishment of slow leukocyte rolling was due to disturbances in intracellular signaling with reduced phosphorylation of phospholipase C (PLC) γ2, Akt, and p38 MAP kinase. Furthermore, CPB induced an elevated transmigration which was caused by upregulation of Mac-1 on neutrophils. These data suggest that CPB abrogates selectin-mediated slow leukocyte rolling by disturbing intracellular signaling, but that the clinically observed increased leukocyte recruitment caused by CPB is due to increased chemokine-induced arrest and transmigration. A better understanding of the underlying molecular mechanisms causing systemic inflammation after CPB may aid in the development of new therapeutic approaches.

The inappropriate activation, positioning, and recruitment of leukocytes are implicated in the pathogenesis of multiple organ failure in sepsis. Although the local anesthetic lidocaine modulates inflammatory processes, the effects of lidocaine in sepsis are still unknown. This double-blinded, prospective, randomized clinical trial was conducted to investigate the effect of lidocaine on leukocyte recruitment in septic patients. Fourteen septic patients were randomized to receive either a placebo (n = 7) or a lidocaine (n = 7) bolus (1.5 mg/kg), followed by continuous infusion (100 mg/h for patients >70 kg or 70 mg/h for patients <70 kg) over a period of 48 h. Selectin-mediated slow rolling, chemokine-induced arrest, and transmigration were investigated by using flow chamber and transmigration assays. Lidocaine treatment abrogated chemokine-induced neutrophil arrest and significantly impaired neutrophil transmigration through endothelial cells by inhibition of the protein kinase C-θ while not affecting the selectin-mediated slow leukocyte rolling. The observed results were not attributable to changes in surface expression of adhesion molecules or selectin-mediated capturing capacity, indicating a direct effect of lidocaine on signal transduction in neutrophils. These data suggest that lidocaine selectively inhibits chemokine-induced arrest and transmigration of neutrophils by inhibition of protein kinase C-θ while not affecting selectin-mediated slow rolling. These findings may implicate a possible therapeutic role for lidocaine in decreasing the inappropriate activation, positioning, and recruitment of leukocytes during sepsis.

During systemic inflammation, leucocytes are activated and extravasate into damaged tissue. Activation and recruitment are influenced by different mechanisms, including the interaction of leucocytes with platelets and neutrophil extracellular traps (NET) formation. Here, we investigated the molecular mechanism by which hydroxyethyl starch (HES 130/0.4) dampens systemic inflammation in vivo. Systemic inflammation was induced in C57Bl/6 wild-type mice by caecal ligation and puncture and cytokine concentrations in the blood, neutrophil recruitment, platelet-neutrophil aggregates, and NET formation were investigated in vivo. Intravascular adherent and transmigrated neutrophils were analysed by intravital microscopy (IVM) of the cremaster muscle and the kidneys. Flow chamber assays were used to investigate the different steps of the leucocyte recruitment cascade. By using flow cytometry, we demonstrated that HES 130/0.4 reduces neutrophil recruitment into the lung, liver, and kidneys during systemic inflammation (n=8 mice per group). IVM revealed a reduced number of adherent and transmigrated neutrophils in the cremaster and kidney after HES 130/0.4 administration (n=8 mice per group). Flow chamber experiments showed that HES 130/0.4 significantly reduced chemokine-induced neutrophil arrest (n=4 mice per group). Furthermore, HES 130/0.4 significantly reduced the formation of platelet-neutrophil aggregates, and NET formation during systemic inflammation (n=8 mice per group). Our findings suggest that HES 130/0.4 significantly reduces neutrophil-platelet aggregates, NET formation, chemokine-induced arrest, and transmigration of neutrophils under inflammatory conditions.

Background: Cardiac surgery patients represent a high-risk cohort in intensive care units (ICUs). Central venous pressure (CVP) measurement seems to remain an integral part in hemodynamic monitoring, especially in cardio-surgical ICUs. However, its value as a prognostic marker for organ failure is still unclear. Therefore, we analyzed postoperative CVP values after adult cardiac surgery in a large cohort with regard to its prognostic value for morbidity and mortality. Methods: All adult patients admitted to our ICUs between 2006 and 2019 after cardiac surgery were eligible for inclusion in the study (n = 11,198). We calculated the median initial CVP (miCVP) after admission to the ICU, which returned valid values for 9802 patients. An ROC curve analysis for optimal cut-off miCVP to predict ICU mortality was conducted with consecutive patient allocation into a (a) low miCVP (LCVP) group (≤11 mmHg) and (b) high miCVP (HCVP) group (>11 mmHg). We analyzed the impact of high miCVP on morbidity and mortality by propensity score matching (PSM) and logistic regression. Results: ICU mortality was increased in HCVP patients. In addition, patients in the HCVP group required longer mechanical ventilation, had a higher incidence of acute kidney injury, were more frequently treated with renal replacement therapy, and showed a higher risk for postoperative liver dysfunction, parametrized by a postoperative rise of ≥ 10 in MELD Score. Multiple regression analysis confirmed HCVP has an effect on postoperative ICU-mortality and intrahospital mortality, which seems to be independent. Conclusions: A high initial CVP in the early postoperative ICU course after cardiac surgery is associated with worse patient outcome. Whether or not CVP, as a readily and constantly available hemodynamic parameter, should promote clinical efforts regarding diagnostics and/or treatment, warrants further investigations.