Prospective clinical study testing the efficacy and safety of a new formula to increase the precision of oxygen therapy in the initiation phase of cardiopulmonary bypass

INTRODUCTION

During cardiopulmonary bypass (CPB), supranormal concentrations of oxygen are routinely administered with the intention to prevent cellular hypoxia. However, hyperoxemia may have adverse effects on patient outcome. Oxygen settings are based on the perfusionist's individual work experience rather than profound recommendations and studies analyzing the effect of oxygen levels are in need of methodological improvement. We aimed to advance perfusion technique by developing and clinically applying a formula for tailored oxygen therapy in CPB.

METHODS

A formula to precalculate the oxygenator setting before CPB was developed. The newly-derived formula was then evaluated in a prospective, single-center pilot study to test whether a predefined arterial partial oxygen pressure (PaO2) of 150-250 mmHg could be reached. 80 patients were enrolled in the study between April and September 2021.

RESULTS

The mean oxygen fraction calculated for the setting of the gas blender was 52% ±0,12. The mean PaO2 after initiation of the CPB was 193 ± 99 mmHg (min-max: 61-484, median 163 mmHg). 38.75% of the values were in the desired PaO2 corridor of 150 to 250 mmHg. 8.75% of all PaO2 values were below <79.9 mmHg, 31.25% between 80 and 149.9 mmHg, 38.75% between 150 and 249.9 mmHg and 21.25%>250 mmHg.

CONCLUSIONS

Conceptually, perfusion technique should be goal-directed, guided by objective parameters and formulas. Although the optimal CPB oxygenation target remains unknown, it is nevertheless important to develop strategies to tailor oxygen therapy to aid in creating evidence as to what level of oxygen is best for patients during CPB. The formula we derived needs further adjustments to increase results in the target range.

Impact of Invasive Pulmonary Aspergillosis in Critically Ill Surgical Patients with or without Solid Organ Transplantation

BACKGROUND

Critically ill patients, especially those who have undergone solid organ transplantation (SOT), are at risk of invasive pulmonary aspergillosis (IPA). The outcome relevance of adequately treated putative IPA (pIPA) is a matter of debate. The aim of this study is to assess the outcome relevance of pIPA in a cohort of critically ill patients with and without SOT.

METHODS

Data from 121 surgical critically ill patients with pIPA (n = 30) or non-pIPA (n = 91) were included. Cox regression analysis was used to identify risk factors for mortality and unfavourable outcomes after 28 and 90 days.

RESULTS

Mortality rates at 28 days were similar across the whole cohort of patients (pIPA: 31% vs. non-pIPA: 27%) and did not differ in the subgroup of patients after SOT (pIPA: 17% vs. non-pIPA: 22%). A higher Sequential Organ Failure Assessment (SOFA) score and evidence of bacteraemia were identified as risk factors for mortality and unfavourable outcome, whereas pIPA itself was not identified as an independent predictor for poor outcomes.

CONCLUSIONS

Adequately treated pIPA did not increase the risk of death or an unfavourable outcome in this mixed cohort of critically ill patients with or without SOT, whereas higher disease severity and bacteraemia negatively affected the outcome.

Microcirculatory tissue oxygenation correlates with kidney function after transcatheter aortic valve implantation-Results from a prospective observational study

Introduction

Kidney dysfunction is common in patients with aortic stenosis (AS) and correction of the aortic valve by transcatheter aortic valve implantation (TAVI) often affects kidney function. This may be due to microcirculatory changes.

Methods

We evaluated skin microcirculation with a hyperspectral imaging (HSI) system, and compared tissue oxygenation (StO₂), near-infrared perfusion index (NIR), tissue hemoglobin index (THI) and tissue water index (TWI) in 40 patients undergoing TAVI versus 20 control patients. HSI parameters were measured before TAVI (t1), directly after TAVI (t2), and on postinterventional day 3 (t3). The primary outcome was the correlation of tissue oxygenation (StO₂) to the creatinine level after TAVI.

Results

We performed 116 HSI image recordings in patients undergoing TAVI for the treatment of severe aortic stenosis and 20 HSI image recordings in control patients. Patients with AS had a lower THI at the palm (p = 0.034) and a higher TWI at the fingertips (p = 0.003) in comparison to control patients. TAVI led to an increase of TWI, but had no uniform enduring effect on StO₂ and THI. Tissue oxygenation StO₂ at both measurement sites correlated negatively with creatinine levels after TAVI at t2 (palm: ρ = -0.415; p = 0.009; fingertip: ρ = -0.519; p < 0.001) and t3 (palm: ρ = -0.427; p = 0.008; fingertip: ρ = -0.398; p = 0.013). Patients with higher THI at t3 reported higher physical capacity and general health scores 120 days after TAVI.

Conclusion

HSI is a promising technique for periinterventional monitoring of tissue oxygenation and microcirculatory perfusion quality, which are related to kidney function, physical capacity, and clinical outcomes after TAVI.

Clinical trial registration

https://drks.de/search/de/trial, identifier DRKS00024765.

Implementation of a spontaneous awakening/spontaneous breathing trial protocol in a surgical intensive care unit: a before and after study

BACKGROUND

Prolonged invasive mechanical ventilation (IMV) influences patient outcome in multiple ways. In this regard the early weaning from IMV is a major goal to be achieved in the treatment of ICU patients. Adopting a weaning protocol that incorporates a Spontaneous Awakening Trial (SAT) and a Spontaneous Breathing Trial (SBT) seems to be essential to reach this goal. Most studies investigating the effectiveness of SAT/SBT protocols in ICU patients' outcomes have focused mainly on medical or mixed (medical and surgical), but not on exclusively surgical patient populations. Surgical patients usually experience more complications and often undergo revision surgeries, therefore needing longer sedation periods and adequate analgo-sedation therapy. Moreover, the longer IMV times make the weaning process more arduous.

METHODS

Our retrospective data analysis therefore investigates the effectiveness of a SAT/SBT protocol implementation in the surgical ICU of Heidelberg University Hospital, focusing exclusively on surgical patients and their outcome related to the weaning process. The SAT/SBT protocol was adopted in Heidelberg ICU starting from 05/2019. We therefore analyzed the time period before and after the implementation between 03/2018 and 08/2020. Adult patients who required invasive ventilation for at least 48 hours were screened for study entry. Demographic data, clinical data and SOFA Score on admission, were collected to define the baseline characteristics of the two groups. Only patients with full adherence to the protocol were included. The primary outcome was defined as the successful extubation, intended as an extubation not followed by successive re-intubations until discharge from the ICU. We performed an univariate analysis to evaluate the rate of successful extubations between the two groups.

RESULTS

In total, 199 patients were included in the analysis, 98 of which before the SAT/SBT protocol implementation (control group) and 101 after the SAT/SBT protocol implementation (intervention group). The successful extubation rate in the intervention group resulted in 82% (83/101 patients) compared to 64% (63/98 patients) in the control group (P<0.004).

CONCLUSIONS

We conclude that even for an exclusively surgical patient population, the implementation of a SAT/SBT protocol could result in a higher rate of successful extubation.

Monocyte Metabolism and Function in Patients Undergoing Cardiac Surgery

Objective

Cardiopulmonary bypass (CPB) can lead to systemic inflammation, which is associated with higher morbidity. Therefore, we investigated the metabolism of isolated blood monocytes before and after CPB compared to healthy controls.

Methods

In this prospective, monocentric, observational study, we included 30 patients undergoing CPB and 20 controls. We isolated monocytes from heparinized blood and investigated their metabolism by using Seahorse technology before (t0), 4 h (t4), and 24 h (t24) after the start of the CPB. We also examined programmed cell death 1 ligand (PD-L1), PD-L2, V-domain Ig suppressor of T cell activation (VISTA), and human leukocyte antigen-DR isotype (HLA-DR) using fluorescence-activated cell sorting analysis. Additionally, we investigated plasma cytokine levels in patients without and after ex vivo stimulation.

Results

CPB-induced inflammatory responses are shown by significantly elevated plasma interleukin-6 levels in the CPB group compared to baseline and controls [t0: 0 ng/ml (95%CI 0-0 ng/ml); t4: 0.16 ng/ml (95%CI 0.1-0.197 ng/ml), p < 0.0001; t24: 0.11 ng/ml (95% CI 0.1-0.16 ng/ml), p < 0.0001, and controls: 0 ng/ml (95% CI 0-0 ng/ml)]. The cytokine release in the ex vivo stimulation is reduced for lipopolysaccharide stimulation at t4 [t0: 35.68 ng/ml (95% CI 22.17-46.57 ng/ml) vs. t4: 15.02 (95% CI 10.25-24.78 ng/ml), p < 0.0001]. Intracellular metabolism of monocytes after CPB showed a protracted shift to aerobic glycolysis [t0: 179.2 pmol/min (95% CI 138.0-205.1 pmol/min) vs. t24: 250.1 pmol/min (95% CI 94.8-300.2 pmol/min), p < 0.0001]. Additionally, we observed an altered metabolism in monocytes in patients undergoing cardiac surgery compared to controls even before any surgical procedure [t0: 179.2 pmol/min (95% CI 138.0-205.1) vs. controls 97.4 (95% CI 59.13-144.6 pmol/min), p = 0.0031].

Conclusion

After CPB, patients' monocytes show a shift in metabolism from oxidative phosphorylation to aerobic glycolysis, which is associated with energy-demanding and proinflammatory processes. This is the first study to show changes in monocyte immunometabolism in cardiac surgery. Monocytes of patients undergoing cardiac surgery were leaning toward aerobic glycolysis even before any surgical procedure was conducted. Leaving the question of the pathophysiological mechanisms for future studies to be investigated and paving the way for potential therapy approaches preventing inflammatory effects of CPB.

"Attention Everyone, Time Out!": Safety Attitudes and Checklist Practices in Anesthesiology in Germany. A Cross-Sectional Study

BACKGROUND

The use of perioperative checklists has generated a growing body of evidence pointing toward reduction of mortality and morbidity, improved compliance with guidelines, reduction of adverse events, and improvements in human factor-related areas. Usual quality management metrics generally fall short in assessing compliance with their perioperative application. Our study assessed application attitudes and compliance with safety measures centered around the World Health Organization (WHO) "Safe Surgery Saves Lives" campaign as perceived by anesthesia professionals in Germany.

METHODS

Three hundred sixteen physicians and nurses participated in our cross-sectional survey, and 304 completed all 35 questions.

RESULTS

Only 59.5% of participants had knowledge of the theoretical framework behind the WHO campaign. During the "sign-in," patient ID and surgical site were checked in 99.6% and 95.1% as recommended by the WHO. Allergies were addressed by 89.2%, expected difficult airway by 65.7%, and the availability of blood products by 70.5%. A total of 84.9% of participants advocated for the time-out to include all persons present in the operating room, which was the case in 57.0%. A total of 40.8% stated that the time-out was only performed between anesthetist and surgeon; in 17.0% of cases, the patient was simultaneously draped and/or surgically scrubbed. No significant differences between hospital types were observed.

CONCLUSIONS

Our study paints a heterogeneous picture of the implementation, usage, and safety attitudes concerning the Safe Surgery Checklist as promoted by the WHO. The lack of standardized execution and team-mindedness can be taken as further evidence for the importance of interdisciplinary training focusing on human factors, communication, and collaboration rather than the mere implementation by decree.

Invasive aspergillosis in solid organ transplant patients: diagnosis, prophylaxis, treatment, and assessment of response

BACKGROUND

Invasive aspergillosis (IA) is a rare complication in solid organ transplant (SOT) recipients. Although IA has significant implications on graft and patient survival, data on diagnosis and management of this infection in SOT recipients are still limited.

METHODS

Discussion of current practices and limitations in the diagnosis, prophylaxis, and treatment of IA and proposal of means of assessing treatment response in SOT recipients.

RESULTS

Liver, lung, heart or kidney transplant recipients have common as well as different risk factors to the development of IA, thus each category needs a separate evaluation. Diagnosis of IA in SOT recipients requires a high degree of awareness, because established diagnostic tools may not provide the same sensitivity and specificity observed in the neutropenic population. IA treatment relies primarily on mold-active triazoles, but potential interactions with immunosuppressants and other concomitant therapies need special attention.

CONCLUSIONS

Criteria to assess response have not been sufficiently evaluated in the SOT population and CT lesion dynamics, and serologic markers may be influenced by the underlying disease and type and severity of immunosuppression. There is a need for well-orchestrated efforts to study IA diagnosis and management in SOT recipients and to develop comprehensive guidelines for this population.

[New antibiotics for severe infections due to multidrug-resistant pathogens : Definitive treatment and escalation]

Multidrug-resistant pathogens often lead to treatment failure of antimicrobial regimens. After a period of imbalance between the occurrence/spread of resistance mechanisms and the development of new substances, some new substances have meanwhile been approved and many more are currently undergoing clinical testing. They are particularly effective against specific resistance mechanisms/pathogens and should be preserved for definitive treatment of an isolated pathogen. In the absence of alternatives reserve antibiotics, such as aztreonam and colistin have experienced a renaissance. They are again used in special infection scenarios and clinically tested in combination with new substances. Despite the introduction and development of new substances the building of resistance will at some time also render these (at least partially) ineffective. Therefore, their implementation must be carried out according to the antibiotic or infectious diseases stewardship.

[Perioperative fluid management in major abdominal surgery]

Intravascular fluid administration belongs to the cornerstones of perioperative treatment with a substantial impact on surgical outcome especially with respect to major abdominal surgery. By avoidance of hypovolemia and hypervolemia, adequate perioperative fluid management significantly contributes to the reduction of insufficient tissue perfusion as a determinant of postoperative morbidity and mortality. The effective use of intravascular fluids requires detailed knowledge of the substances as well as measures to guide fluid therapy. Fluid management already starts preoperatively and should be continued in the postoperative setting (recovery room, peripheral ward) considering a patient-adjusted and surgery-adjusted hemodynamic monitoring. Communication between all team members participating in perioperative care is essential to optimize fluid management.

[Findings from 10 years of CIRS-AINS : An analysis of usepatterns and insights into new challenges]

Hintergrund

„Critical-incident-reporting“-Systeme (CIRS) dienen dazu, Organisationen und Individuen für bislang unbekannte und sicherheitsrelevante Ereignisse zu sensibilisieren und dadurch Veränderungen herbeiführen zu können. In den letzten Jahren häufen sich allerdings kritische Stimmen, die Einsatz und Nutzen von CIRS in der Medizin hinterfragen, u. a. aufgrund unklarer bzw. zu allgemeiner inhaltlicher Kriterien für die Aufnahme einer Meldung in ein System. Ziel der Arbeit ist die Auswertung und Analyse aller Fälle aus CIRSmedical Anästhesiologie (CIRS-AINS) als Grundlage weiterer, differenzierter Betrachtungen.

Methode

In einer retrospektiven Datenbankanalyse wurden alle Fälle aus CIRS-AINS (April 2010–Juni 2019) inhaltlich analysiert.

Ergebnisse

Die gemeldeten 6013 Fälle setzen sich aus 3492 „incidents“ (58,1 %), 1734 „near-misses“ (28,8 %) und 787 sonstigen Meldungen (13,1 %) zusammen. Unter Letztere fielen 21 Konfliktmeldungen (0,4 %), 102 Beschwerden (1,7 %), 89 Überlastungsanzeigen (1,5 %) sowie 575 sonstige Meldungen, die keine CIRS-Fälle darstellen (9,6 %). Seit 2015 zeigt sich eine stetige Zunahme der sonstigen Meldungen um das 2,8-Fache von 7,4 % auf 20,8 %. In 20,1 % der Meldungen wurde Technik, in 27,7 % Medizinprodukte erwähnt. Medikamente waren in 10,7 % der Meldungen Gegenstand der Zwischenfälle. Aus dem perioperativen Umfeld wurden 47,8 % der stationären Zwischenfälle berichtet, 24,6 % aus den Bereichen Intensivstation/Aufwachraum. Das CIRS-Team des BDA analysierte und kommentierte 36,1 % der Fälle .

Schlussfolgerung

Die Analyse liefert Erkenntnisse für die Gestaltung zukünftiger Melderichtlinien und Anwenderschulungen. Insbesondere der Häufung „sonstiger“ Meldungen, welche nicht den Kriterien einer CIRS-Meldung entsprechen, sollte künftig Rechnung getragen werden.

Impact of a semi-structured briefing on the management of adverse events in anesthesiology: a randomized pilot study

Background

Human factors research has identified mental models as a key component for the effective sharing and organization of knowledge. The challenge lies in the development and application of tools that help team members to arrive at a shared understanding of a situation. The aim of this study was to assess the influence of a semi-structured briefing on the management of a simulated airway emergency.

Methods

37 interprofessional teams were asked to perform a simulated rapid-sequence induction in the simulator. Teams were presented with a “cannot ventilate, cannot oxygenate” scenario that ultimately required a cricothyroidotomy. Study group (SG) teams were asked to perform a briefing prior to induction, while controls (CG) were asked to perform their usual routine.

Results

We observed no difference in the mean time until cricothyroidotomy (SG 8:31 CG 8:16, p = 0.36). There was a significant difference in groups’ choice of alternative means of oxygenation: While SG teams primarily chose supraglottic airway devices, controls initially reverted to mask ventilation (p = 0.005). SG teams spent significantly less time with this alternative airway device and were quicker to advance in the airway algorithm.

Conclusions

Our study addresses effects on team coordination through a shared mental model as effected by a briefing prior to anesthesia induction. We found measurable improvements in airway management during those stages of the difficult airway algorithm explicitly discussed in the briefing. For those, time spent was shorter and participants were quicker to advance in the airway algorithm.

Applying the human factors analysis and classification system to critical incident reports in anaesthesiology

BACKGROUND

The Human Factors Analysis and Classification System (HFACS) was developed as a practical taxonomy to investigate and analyse the human contribution to accidents and incidents. Based on Reason's "Swiss Cheese Model", it considers individual, environmental, leadership and organizational contributing factors in four hierarchical levels. The aim of this study was to assess the applicability of a modified HFACS taxonomy to incident reports from a large, anonymous critical incident database with the goal of gaining valuable insight into underlying, more systemic conditions and recurring schemes that might add important information for future incident avoidance.

METHODS

We analysed 50 reports from an anonymous, anaesthesiologic, single-centre Critical Incident Reporting System using a modified HFACS-CIRS taxonomy. The 19 HFACS categories were further subdivided into a total of 117 nanocodes representing specific behaviours or preconditions for incident development.

RESULTS

On an individual level, the most frequent contributions were decision errors, attributed to inadequate risk assessment or critical-thinking failure. Communication and Coordination, mostly due to inadequate or ineffective communication, was contributory in two-thirds of reports. Half of the reports showed contributory complex interactions in a sociotechnical environment. Ratability scores were noticeably lower for categories evaluating leadership and organizational influences, necessitating careful interpretation.

CONCLUSIONS

We applied the HFACS taxonomy to the analysis of CIRS reports in anaesthesiology. This constitutes a structured approach that, especially when applied to a large data set, might help guide future mitigation and intervention strategies to reduce critical incidents and improve patient safety. Improved, more structured reporting templates could further optimize systematic analysis.

Impact of human sepsis on CCCTC-binding factor associated monocyte transcriptional response of Major Histocompatibility Complex II components

Background

Antigen presentation on monocyte surface to T-cells by Major Histocompatibility Complex, Class II (MHC-II) molecules is fundamental for pathogen recognition and efficient host response. Accordingly, loss of Major Histocompatibility Complex, Class II, DR (HLA-DR) surface expression indicates impaired monocyte functionality in patients suffering from sepsis-induced immunosuppression. Besides the impact of Class II Major Histocompatibility Complex Transactivator (CIITA) on MHC-II gene expression, X box-like (XL) sequences have been proposed as further regulatory elements. These elements are bound by the DNA-binding protein CCCTC-Binding Factor (CTCF), a superordinate modulator of gene transcription. Here, we hypothesized a differential interaction of CTCF with the MHC-II locus contributing to an altered monocyte response in immunocompromised septic patients.

Methods

We collected blood from six patients diagnosed with sepsis and six healthy controls. Flow cytometric analysis was used to identify sepsis-induced immune suppression, while inflammatory cytokine levels in blood were determined via ELISA. Isolation of CD14⁺⁺ CD16^—monocytes was followed by (i) RNA extraction for gene expression analysis and (ii) chromatin immunoprecipitation to assess the distribution of CTCF and chromatin modifications in selected MHC-II regions.

Results

Compared to healthy controls, CD14⁺⁺ CD16^—monocytes from septic patients with immune suppression displayed an increased binding of CTCF within the MHC-II locus combined with decreased transcription of CIITA gene. In detail, enhanced CTCF enrichment was detected on the intergenic sequence XL9 separating two subregions coding for MHC-II genes. Depending on the relative localisation to XL9, gene expression of both regions was differentially affected in patients with sepsis.

Conclusion

Our experiments demonstrate for the first time that differential CTCF binding at XL9 is accompanied by uncoupled MHC-II expression as well as transcriptional and epigenetic alterations of the MHC-II regulator CIITA in septic patients. Overall, our findings indicate a sepsis-induced enhancer blockade mediated by variation of CTCF at the intergenic sequence XL9 in altered monocytes during immunosuppression.

Plasma sRAGE is independently associated with increased mortality in ARDS: a meta-analysis of individual patient data

PURPOSE

The soluble receptor for advanced glycation end-products (sRAGE) is a marker of lung epithelial injury and alveolar fluid clearance (AFC), with promising values for assessing prognosis and lung injury severity in acute respiratory distress syndrome (ARDS). Because AFC is impaired in most patients with ARDS and is associated with higher mortality, we hypothesized that baseline plasma sRAGE would predict mortality, independently of two key mediators of ventilator-induced lung injury.

METHODS

We conducted a meta-analysis of individual data from 746 patients enrolled in eight prospective randomized and observational studies in which plasma sRAGE was measured in ARDS articles published through March 2016. The primary outcome was 90-day mortality. Using multivariate and mediation analyses, we tested the association between baseline plasma sRAGE and mortality, independently of driving pressure and tidal volume.

RESULTS

Higher baseline plasma sRAGE [odds ratio (OR) for each one-log increment, 1.18; 95% confidence interval (CI) 1.01-1.38; P = 0.04], driving pressure (OR for each one-point increment, 1.04; 95% CI 1.02-1.07; P = 0.002), and tidal volume (OR for each one-log increment, 1.98; 95% CI 1.07-3.64; P = 0.03) were independently associated with higher 90-day mortality in multivariate analysis. Baseline plasma sRAGE mediated a small fraction of the effect of higher ΔP on mortality but not that of higher VT.

CONCLUSIONS

Higher baseline plasma sRAGE was associated with higher 90-day mortality in patients with ARDS, independently of driving pressure and tidal volume, thus reinforcing the likely contribution of alveolar epithelial injury as an important prognostic factor in ARDS. Registration: PROSPERO (ID: CRD42018100241).

[Bacterial sepsis : Diagnostics and calculated antibiotic therapy]

The mortality of patients with sepsis and septic shock is still unacceptably high. An effective antibiotic treatment within 1 h of recognition of sepsis is an important target of sepsis treatment. Delays lead to an increase in mortality; therefore, structured treatment concepts form a rational foundation, taking relevant diagnostic and treatment steps into consideration. In addition to the assumed focus and individual risks of each patient, local resistance patterns and specific problem pathogens must be taken into account for selection of anti-infection treatment. Many pathophysiological alterations influence the pharmacokinetics of antibiotics during sepsis. The principle of standard dosing should be abandoned and replaced by an individual treatment approach with stronger weighting of the pharmacokinetics/pharmacodynamics (PK/PD) index of the substance groups. Although this is not yet the clinical standard, prolonged (or continuous) infusion of beta-lactam antibiotics and therapeutic drug monitoring (TDM) can help to achieve defined PK targets. Prolonged infusion is sufficient without TDM but for continuous infusion TDM is basically necessary. A further argument for individual PK/PD-oriented antibiotic approaches is the increasing number of infections due to multidrug resistant pathogens (MDR) in the intensive care unit. For effective treatment antibiotic stewardship teams (ABS team) are becoming more established. Interdisciplinary cooperation of the ABS team with infectiologists, microbiologists and clinical pharmacists leads not only to a rational administration of antibiotics but also has a positive influence on the outcome. The gold standards for pathogen detection are still culture-based detection and microbiological resistance testing for the various antibiotic groups. Despite the rapid investigation time, novel polymerase chain reaction (PCR)-based procedures for pathogen identification and resistance determination, are currently only an adjunct to routine sepsis diagnostics due to the limited number of studies, high costs and limited availability. In complicated septic courses with multiple anti-infective treatment or recurrent sepsis, PCR-based procedures can be used in addition to therapy monitoring and diagnostics. Novel antibiotics represent potent alternatives in the treatment of MDR infections. Due to the often defined spectrum of pathogens and the practically absent resistance, they are suitable for targeted treatment of severe MDR infections (therapy escalation).

Inflammation and Its Consequences After Surgical Versus Transcatheter Aortic Valve Replacement

Symptomatic aortic stenosis can be treated by surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR), the latter of which is regarded as a minimally invasive procedure. Differences between these procedures regarding immune responses or changes in coagulation and neurocognitive function have thus far been evaluated only sparsely. We carried out a prospective, single-center, nonrandomized explorative study with 38 patients. Thirteen patients were subjected to either SAVR or transfemoral (TF-) TAVR, and 12 patients underwent transapical (TA-) TAVR. Plasma cytokines (IL-6, -8, -18, presepsin) and acute-phase proteins (C-reactive protein, procalcitonin), markers of coagulation and platelet function, and neurocognitive function (via various standard tests) were assessed before and at five-time points during a 72-h follow-up after surgery. SAVR and TA-TAVR patients responded similarly to the procedure in terms of C-reactive protein, leukocyte numbers, and IL-6, whereas these responses were substantially lower in TF-TAVR patients. Only SAVR patients showed measurable IL-10 levels. SAVR patients without prior anticoagulation experienced a robust and transient restoration of platelet function after surgery, with no hypercoagulation observable in functional coagulation assays. None of the procedures led to an immediate improvement of hand and leg coordination, but patients after TA-TAVR had decreased neurocognitive function. Patients after SAVR or TA-TAVR exhibit a robust pro-inflammatory response, which is-on the cytokine level-counterbalanced only in SAVR patients. Our results point toward a greater impact of TA-TAVR on neurocognitive function and indicate a potentially detrimental activation of platelets in some patients after SAVR.

Microbiomic Analysis of Intra-Abdominal Infections by Using Denaturing High-Performance Liquid Chromatography: A Prospective Observational Study

BACKGROUND

Intra-abdominal infections represent a subgroup of septic syndromes with high death rates and the need for prompt and appropriate antimicrobial therapy. Conventional culture-based microbial identification has notable shortcomings in the diagnostics of polymicrobial infections. Modern culture-independent molecular methods may represent a new diagnostic approach. The current study aimed to compare the results obtained from the denaturing high-performance liquid chromatography WAVE^® system as a culture-independent diagnostic tool with those obtained from standard culture-based microbiologic testing in the clinical setting of severe intra-abdominal sepsis.

PATIENTS AND METHODS

The study included 42 samples of pathologic intra-abdominal fluids, collected from 37 patients with intra-abdominal sepsis. Micro-organisms grown in culture and detected by the WAVE system were compared. Further, we recorded clinical data including baseline characteristics and the use of antibiotic agents.

RESULTS

In 38.1% of the analyzed samples, the classic, culture-based methods showed no bacterial growth on agar plates, in comparison with the microbiomic analysis in which the proportion of samples with negative signal was 31%. In about 40% of the patients, both methods detected one microbiologic agent, whereas in approximately one quarter of the samples, two or more agents were identified. The detection rate of certain bacteria such as Enterobacteriacae or Enterococcus faecium was significantly higher using the microbiomic analysis. Bacteria such as Haemophilus, Lactobacillus, Clostridium, Methylobacterium, Collinsella aerofaciens, and Solobacterium moorei were detected exclusively using microbiomic analysis.

CONCLUSION

The culture independent molecular WAVE system provided additional information, especially concerning unusual, fastidious bacteria in patients with intra-abdominal infections. Further, it has a higher detection rate for polymicrobial infection and delivers results much sooner than conventional microbiologic methods.

The impact of real life treatment strategies for Candida peritonitis-A retrospective analysis

Candida species are commonly detected isolates from abdominal foci. The question remains as to who would benefit from early empiric treatment in cases of Candida peritonitis. This study collected real-life data on critically ill patients with Candida peritonitis to estimate the relevance of the chosen treatment strategy on the outcome of these patients. One hundred and thirty-seven surgical intensive care unit (ICU) patients with intra-abdominal invasive Candidiasis were included in the study. Fifty-six patients did not get any antifungal agent. Twenty-nine patients were empirically treated, and 52 patients were specifically treated. In the group without, with empiric and with specific antifungal treatment, the 30-day mortality rate was 33.9, 48.3 and 44.2 respectively. Candida albicans was the most frequently found species. Seven patients in the specific treatment group and one patient in the empiric treatment group emerged with candidaemia. Age, leucocyte count, APACHE II Score and acute liver failure were independent predictors of 30-day mortality in patients with Candida peritonitis. Not all patients with Candida peritonitis received antifungal treatment in real clinical practice. Patients with higher morbidity more often got antifungals. Early empirical therapy has not been associated with a better 30-day mortality.

Concurrent Left Ventricular Assist Device (LVAD) Implantation and Percutaneous Temporary RVAD Support via CardiacAssist Protek-Duo TandemHeart to Preempt Right Heart Failure

Right ventricular failure (RVF) is an unfortunate complication that continues to limit outcomes following durable left ventricular assist device (LVAD) implantation. Despite several ‘RVF risk scores’ having been proposed, preoperative prediction of post-LVAD RVF remains a guesstimate at best. Current strategies for institution of temporary RVAD support are invasive, necessitate additional re-thoracotomy, restrict postoperative mobilization, and/or entail prolonged retention of prosthetic material in-situ. The authors propose a novel surgical strategy comprising simultaneous implantation of a permanent LVAD and percutaneous TandemHeart^® plus ProtekDuo^® to provide temporary RVAD support and preempt RVF in patients with impaired RV function.

Sepsis-induced long-term immune paralysis--results of a descriptive, explorative study

Background

Long-lasting impairment of the immune system is believed to be the underlying reason for delayed deaths after surviving sepsis. We tested the hypothesis of persisting changes to the immune system in survivors of sepsis for the first time.

Methods

In our prospective, cross-sectional pilot study, eight former patients who survived catecholamine-dependent sepsis and eight control individuals matched for age, sex, diabetes and renal insufficiency were enrolled. Each participant completed a questionnaire concerning morbidities, medications and infection history. Peripheral blood was collected for determination of i) immune cell subsets (CD4⁺, CD8⁺ T cells; CD25⁺ CD127^- regulatory T cells; CD14⁺ monocytes), ii) cell surface receptor expression (PD-1, BTLA, TLR2, TLR4, TLR5, Dectin-1, PD-1 L), iii) HLA-DR expression, and iv) cytokine secretion (IL-6, IL10, TNF-α, IFN-γ) of whole blood stimulated with either α-CD3/28, LPS or zymosan.

Results

After surviving sepsis, former patients presented with increased numbers of clinical apparent infections, including those typically associated with an impaired immune system. Standard inflammatory markers indicated a low-level inflammatory situation in former sepsis patients. CD8⁺ cell surface receptor as well as monocytic HLA-DR density measurements showed no major differences between the groups, while CD4⁺ T cells tended towards two opposed mechanisms of negative immune cell regulation via PD-1 and BTLA. Moreover, the post-sepsis group showed alterations in monocyte surface expression of distinct pattern recognition receptors; most pronouncedly seen in a decrease of TLR5 expression. Cytokine secretion in response to important activators of both the innate (LPS, zymosan) and the adaptive immune system (α-CD3/28) seemed to be weakened in former septic patients.

Conclusions

Cytokine secretion as a reaction to different activators of the immune system seemed to be comprehensively impaired in survivors of sepsis. Among others, this could be based on trends in the downregulation of distinct cell surface receptors. Based on our results, the conduct of larger validation studies seems feasible, aiming to characterize alterations and to find potential therapeutic targets to engage.

[Patient safety in anesthesiology : Multimodal strategies for perioperative care]

The concept of patient safety is more of a presence in modern day medicine than ever before. All measures and processes aiming at preempting and preventing critical incidents and accidents in patient care are collectively grouped under this concept. With the Declaration of Helsinki in 2010 modern anesthesiology has undertaken a fundamental role in the clinical implementation and perioperative clinicians are confronted with a multitude of theories, models, methods and tools targeted at improving or facilitating optimized patient safety. One of the biggest challenges lies in their synergistic combination to create a functioning concept for perioperative risk management while also incorporating individual strengths and weaknesses. The aim of the present paper is to provide a structured overview of the various components presently available for increasing perioperative patient safety.

Galactomannan and Zymosan Block the Epinephrine-Induced Particle Transport in Tracheal Epithelium

BACKGROUND

Ciliary beating by respiratory epithelial cells continuously purges pathogens from the lower airways. Here we investigated the effect of the fungal cell wall polysaccharides Galactomannan (GM) and Zymosan (Zym) on the adrenergic activated particle transport velocity (PTV) of tracheal epithelium.

METHODS

Experiments were performed using tracheae isolated from male C57BL/6J mice. Transport velocity of the cilia bearing epithelial cells was measured by analysing recorded image sequences. Generation of reactive oxygen species (ROS) were determined using Amplex Red reagents. PCR experiments were performed on isolated tracheal epithelium to identify adrenergic receptor mRNA.

RESULTS

The adrenergic receptors α1D, α2A, β1 and β2 have been identified in isolated tracheal epithelium. We found epinephrine responsible for an increase in PTV, which could only be reduced by selective β-receptor-inhibition. In addition, either GM or Zym prevented the epinephrine induced PTV increase. Furthermore, we observed a strong ROS generation evoked by GM or Zym. However, epinephrine induced increase in PTV recovered in the presence of GM and Zym after application of ROS scavengers.

CONCLUSION

Both GM or Zym trigger reversible ROS generation in tracheal tissue leading to inhibition of the β-adrenergic increase in PTV.

The impact of early surgical intervention in free intestinal perforation: a time-to-intervention pilot study

PURPOSES

An abdominal inflammatory focus is the second most often source of sepsis with a high risk of death in surgical intensive care units. By establishing evidence-based bundled strategies the surviving sepsis campaign provided an optimized rapid and continuous treatment of these emergency patients. Hereby the hospital mortality decreased from 35 to 30 %. Sepsis treatment is based on three major therapeutic elements: surgical treatment (source control), antiinfective treatment, and supportive care. The international guidelines of the surviving sepsis campaign were updated recently and recommend rapid diagnosis of the infection and source control within the first 12 h after the diagnosis (grade 1c). Interestingly this recommendation is mainly based on studies on soft tissue infections.

METHODS

In this retrospective analysis 76 septic patients with an intraabdominal inflammatory focus were included. All patients underwent surgery at different time-points after diagnosis.

RESULTS

With 80 % patients of the early intervention group had an improved overall survival (vs. 73 % in the late intervention group).

CONCLUSIONS

Literature on the time dependency of early source control is rare and in part contradicting. Results of this pilot study reveal that immediate surgical intervention might be of advantage for septic emergency patients. Further multi-center approaches will be necessary to evaluate, whether the TTI has any impact on the outcome of septic patients with intestinal perforation.

[Use of biomarkers in sepsis. Update and perspectives]

Sepsis and related complications are a challenge for intensive care medicine. Despite many advances in antibiotic therapy sepsis remains one of the most common diseases of patients in intensive care units and is designated as the main cause of death in critically ill patients. Persisting sepsis leads to impaired immunity, resulting in immunosuppression. Unspecific predictive signs complicate an early diagnosis; however, an early initiation of adequate therapy is of crucial importance for the prognosis. Scoring systems can be applied for the initial evaluation but are controversially discussed concerning the monitoring of disease progression and therapy as well as outcome prediction. Biomarkers are considered as a complementary approach.

Relevance of Candida and other mycoses for morbidity and mortality in severe sepsis and septic shock due to peritonitis

This single-centre retrospective cohort study evaluated the incidence and outcome of mycoses in critical ill patients (n = 283) with sepsis due to peritonitis. Overall mortality was 41.3%, and the 28-day mortality was 29.3%. Fungal pathogens were found in 51.9%. The common first location was the respiratory tract (66.6%), followed by the abdominal site (19.7%). Candida colonisation was found in 64.6%, and invasive Candida infection in 34.0%. Identified fungi were Candida spp. in 98.6% and Aspergillus spp. in 6.1%. Patients with fungal pathogens showed a higher rate of postoperative peritonitis, APACHE II and tracheotomy. In comparison to patients without fungal pathogens, these patients showed a longer duration on mechanical ventilation, and a higher overall mortality. Patients with Candida-positive swabs from abdominal sites had more fascia dehiscence and anastomosis leakage. Seventy-two patients (48.9%) received antifungal therapy, 26 patients were treated empirically. Antifungal therapy was not associated with a decrease in mortality. Age and renal replacement therapy were associated with mortality. In conclusion, fungi are common pathogens in critically ill patients with peritonitis, and detection of fungi is associated with an increase in overall mortality. Particularly, Candida-positive abdominal swabs are associated with an increase in morbidity. However, we were not able to demonstrate a survival benefit for antifungal therapy in peritonitis patients.

Are there new approaches for diagnosis, therapy guidance and outcome prediction of sepsis?

Beside many efforts to improve outcome, sepsis is still one of the most frequent causes of death in critically ill patients. It is the most common condition with high mortality in intensive care units. The complexity of the septic syndrome comprises immunological aspects - i.e., sepsis induced immunosuppression - but is not restricted to this fact in modern concepts. So far, exact mechanisms and variables determining outcome and mortality stay unclear. Since there is no typical risk profile, early diagnosis and risk stratification remain difficult, which hinders rapid and effective treatment initiation. Due to the heterogeneous nature of sepsis, potential therapy options should be adapted to the individual. Biomarkers like C-reactive protein and procalcitonin are routinely used as complementary tools in clinical decision-making. Beyond the acute phase proteins, a wide bunch of promising substances and non-laboratory tools with potential diagnostic and prognostic value is under intensive investigation. So far, clinical decision just based on biomarker assessment is not yet feasible. However, biomarkers should be considered as a complementary approach.

Sepsis induces specific changes in histone modification patterns in human monocytes

Background

Sepsis is a global burden and the primary cause of death in intensive care units worldwide. The pathophysiological changes induced by the host’s systemic inflammatory response to infection are not yet fully understood. During sepsis, the immune system is confronted with a variety of factors, which are integrated within the individual cells and result in changes of their basal state of responsiveness. Epigenetic mechanisms like histone modifications are known to participate in the control of immune reactions, but so far the situation during sepsis is unknown.

Methods and Findings

In a pilot approach, we performed combined chromatin immunoprecipitation followed by high-throughput sequencing to assess the genome-wide distribution of the chromatin modifications histone 3 lysine 4 and 27 trimethylation and lysine 9 acetylation in monocytes isolated from healthy donors (n = 4) and patients with sepsis (n = 2). Despite different underlying causes for sepsis, a comparison over promoter regions shows a high correlation between the patients for all chromatin marks. These findings hold true also when comparing patients to healthy controls. Despite the global similarity, differential analysis reveals a set of distinct promoters with significant enrichment or depletion of histone marks. Further analysis of overrepresented GO terms show an enrichment of genes involved in immune function. To the most prominent ones belong different members of the HLA family located within the MHC cluster together with the gene coding for the major regulator of this locus—CIITA.

Conclusions

We are able to show for the first time that sepsis in humans induces selective and precise changes of chromatin modifications in distinct promoter regions of immunologically relevant genes, shedding light on basal regulatory mechanisms that might be contributing to the functional changes occurring in monocytes.

[Pathophysiology of sepsis]

Our understanding of the causes and pathophysiological basis of sepsis has been subject to constant change over the last decades. In today's understanding, sepsis is primarily a pathology of the immune system, triggered by an underlying infection but perpetuated by the host's response itself. Thereby, sepsis should not be categorized to be either a sole pro- or anti-inflammatory syndrome, but rather as a variable continuum of overlaying immune mechanisms. While a overshooting immune reaction predominates in early sepsis, this reaction is rapidly compensated, often leading to a immune dysfunction, rendering the host susceptible for secondary infections. This review aims to provide the reader with an overview of the broad molecular mechanisms contributing to the clinical picture of sepsis.

[Epigenetic regulation in sepsis : current state of knowledge]

Sepsis is known to be a severe systemic immune reaction based on an infection of various origins. The initial immune response is accompanied by excess activation of immune cells and release of proinflammatory cytokines. Simultaneously initiated compensatory mechanisms lead to high levels of anti-inflammatory mediators to counterbalance the generalized inflammatory reaction; however, the compensatory immunoreaction itself equally overreacts and results in a prolonged sepsis-induced immunosuppression. The underlying mechanisms for these exaggerated immune responses and the resulting global immunosuppression that increase the risk for secondary infection are still unknown. Recent findings indicate that epigenetic mechanisms change basic properties of important immune cells by mechanisms leading to changes in gene expression. Dynamic exchanges of histone modifications result in a variation of transcription and seem to play a key role in cell function of macrophages and other immune cells. This article provides a current overview of epigenetic sepsis research and the sepsis-induced effects on the immune system.

The early antibiotic therapy in septic patients--milestone or sticking point?

Sepsis is one of the oldest and most elusive syndromes in medicine. Every effort should be made to treat these patients with the best available evidence. As a milestone, empiric antimicrobial therapy is essential in order to reduce morbidity and mortality of septic patients. As a sticking point, the use of broad-spectrum antimicrobial agents may be associated with induction of resistance among common pathogens.

Loss of vagal tone aggravates systemic inflammation and cardiac impairment in endotoxemic rats

BACKGROUND

During the course of sepsis, often myocardial depression with hemodynamic impairment occurs. Acetylcholine, the main transmitter of the parasympathetic Nervus vagus, has been shown to be of importance for the transmission of signals within the immune system and also for a variety of other functions throughout the organism. Hypothesizing a potential correlation between this dysfunction and hemodynamic impairment, we wanted to assess the impact of vagal stimulation on myocardial inflammation and function in a rat model of lipopolysaccharide (LPS)-induced septic shock. As the myocardial tissue is (sparsely) innervated by the N. vagus, there might be an important anti-inflammatory effect in the heart, inhibiting proinflammatory gene expression in cardiomyocytes and improving cardiac function.

MATERIALS AND METHODS

We performed stimulation of the right cervical branch of the N. vagus in vagotomized, endotoxemic (1 mg/kg body weight LPS, intravenously) rats. Hemodynamic parameters were assessed over time using a left ventricular pressure-volume catheter. After the experiments, hearts and blood plasma were collected, and the expression of proinflammatory cytokines was measured using quantitative reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay.

RESULTS

After vagotomy, the inflammatory response was aggravated, measurable by elevated cytokine levels in plasma and ventricular tissue. In concordance, cardiac impairment during septic shock was pronounced in these animals. To reverse both hemodynamic and immunologic effects of diminished vagal tone, even a brief stimulation of the N. vagus was enough during initial LPS infusion.

CONCLUSIONS

Overall, the N. vagus might play a major role in maintaining hemodynamic stability and cardiac immune homeostasis during septic shock.

Diagnosis and management for urosepsis

Urosepsis is defined as sepsis caused by a urogenital tract infection. Urosepsis in adults comprises approximately 25% of all sepsis cases, and is in most cases due to complicated urinary tract infections. The urinary tract is the infection site of severe sepsis or septic shock in approximately 10-30% of cases. Severe sepsis and septic shock is a critical situation, with a reported mortality rate nowadays still ranging from 30% to 40%. Urosepsis is mainly a result of obstructed uropathy of the upper urinary tract, with ureterolithiasis being the most common cause. The complex pathogenesis of sepsis is initiated when pathogen or damage-associated molecular patterns recognized by pattern recognition receptors of the host innate immune system generate pro-inflammatory cytokines. A transition from the innate to the adaptive immune system follows until a T(H2) anti-inflammatory response takes over, leading to immunosuppression. Treatment of urosepsis comprises four major aspects: (i) early diagnosis; (ii) early goal-directed therapy including optimal pharmacodynamic exposure to antimicrobials both in the plasma and in the urinary tract; (iii) identification and control of the complicating factor in the urinary tract; and (iv) specific sepsis therapy. Early adequate tissue oxygenation, adequate initial antibiotic therapy, and rapid identification and control of the septic focus in the urinary tract are critical steps in the successful management of a patient with urosepsis, which includes early imaging, and an optimal interdisciplinary approach encompassing emergency unit, urological and intensive-care medicine specialists.

[Near-infrared spectroscopy in sepsis therapy : predictor of a low central venous oxygen saturation]

BACKGROUND

Early goal-directed hemodynamic optimization has become a cornerstone of sepsis therapy. One major defined goal is to achieve adequate central venous oxygen saturation (SO(2)). This study aimed to investigate the correlation between central venous SO(2) and frontal cerebral near-infrared spectroscopy (NIRS) measurement in patients with severe sepsis and septic shock. The NIRS method provides non-invasive measurement of regional oxygen saturation (rSO(2)) in tissues approximately 2 cm below the optical NIRS sensors which depends on arterial, capillary and venous blood. Thus this system gives site-specific real-time data about the balance of oxygen supply and demand.

METHODS

This was a secondary analysis from a prospective study of surgical intensive care (ICU) patients in the early phase of severe sepsis or septic shock. Bilateral cerebral rSO(2), central venous SO(2), arterial oxygen saturation (S(a)O(2)) and other surrogate parameters of oxygen supply, such as hemoglobin, partial pressure of oxygen and oxygen content in arterial blood were recorded.

RESULTS

A total of 16 ICU patients (4 women, median age 65.5 years) were included in the study. As sepsis focus an intra-abdominal infection was detected in 62.5 % of patients, severe pneumonia was determined in 31.3 % and skin and soft tissue infections were recognized in 12.5 %. At study inclusion 50 % of patients had septic shock, the median sequential organ failure assessment (SOFA) score was 10.2 (interquartile range 5.25-8.75) and the median acute physiology and chronic health evaluation II (APACHE II) score was 26 (range 23.25-29.75). Mortality at day 28 was 37.5 %. Minimum rSO(2) (median 58) and right-sided rSO(2) (median 58) values showed a significant correlation in the analysis of receiver operating characteristics (area under the curve 0.844, p= 0.045). A central venous SO(2)< 70 % was indicated by rSO(2)< 56.5 with sensitivity and specificity of 75 % and 100 %, respectively.

CONCLUSIONS

Cerebral NIRS could provide a fast and easily available side effect-free monitoring that could be used in addition to established procedures for goal-directed treatment in the early phase of sepsis. Further studies should be made in a larger population to verify the correlation found and to investigate the impact of NIRS-directed resuscitation treatment in early sepsis.