Isoflurane, like sepsis, decreases CYP1A2 liver enzyme activity in intensive care patients: a clinical study and network model

PURPOSE

Liver function of intensive care patients is routinely monitored by static blood pathology. For specific indications, liver specific cytochrome activity may be measured by the commercially available maximum liver function capacity (LiMAx) test via quantification of the cytochrome P450 1A2 (CYP1A2) dependent C-methacetin metabolism. Sedation with the volatile anesthetic isoflurane was suspected to abrogate the correlation of LiMAx test with global liver function. We hypothesized that isoflurane has a CYP1A2-activity and LiMAx test result decreasing effect.

METHODS

In this monocentric, observational clinical study previously liver healthy intensive care patients, scheduled to be changed from propofol to isoflurane sedation, were enrolled. LiMAx testing was done before, during and after termination of isoflurane sedation.

RESULTS

The mean LiMAx value decreased during isoflurane sedation. Septic patients (n = 11) exhibited lower LiMAx values compared to non-septic patients (n = 11) at all time points. LiMAx values decreased with isoflurane from 140 ± 82 to 30 ± 34 µg kg-1 h-1 in the septic group and from 253 ± 92 to 147 ± 131 µg kg-1 h-1 in the non-septic group while laboratory markers did not imply significant hepatic impairment. Lactate increased during isoflurane inhalation without clinical consequence.

CONCLUSION

Sepsis and isoflurane have independently demonstrated an effect on reducing the hepatic CYP1A2-activity. A network model was constructed that could explain the mechanism through the influence of isoflurane on hypoxia inducible factor (HIF-1α) by upregulation of the hypoxia-inducible pathway and the downregulation of CYP1A2-activity via the ligand-inducible pathway. Thus, the increased anaerobic metabolism may result in lactate accumulation. The influence of isoflurane sedation on the validated correlation of global liver function with CYP1A2-activity measured by LiMAx testing needs to be investigated in more detail.

The Association between the rs3747406 Polymorphism in the Glucocorticoid-Induced Leucine Zipper Gene and Sepsis Survivals Depends on the SOFA Score

The variability in mortality in sepsis could be a consequence of genetic variability. The glucocorticoid system and the intermediate TSC22D3 gene product-glucocorticoid-induced leucine zipper-are clinically relevant in sepsis, which is why this study aimed to clarify whether TSC22D3 gene polymorphisms contribute to the variance in sepsis mortality. Blood samples for DNA extraction were obtained from 455 patients with a sepsis diagnosis according to the Sepsis-III criteria and from 73 control subjects. A SNP TaqMan assay was used to detect single-nucleotide polymorphisms (SNPs) in the TSC22D3 gene. Statistical and graphical analyses were performed using the SPSS Statistics and GraphPad Prism software. C-allele carriers of rs3747406 have a 2.07-fold higher mortality rate when the sequential organ failure assessment (SOFA) score is higher than eight. In a multivariate COX regression model, the SNP rs3747406 with a SOFA score ≥ 8 was found to be an independent risk factor for 30-day survival in sepsis. The HR was calculated to be 2.12, with a p-value of 0.011. The wild-type allele was present in four out of six SNPs in our cohort. The promoter of TSC22D3 was found to be highly conserved. However, we discovered that the C-allele of rs3747406 poses a risk for sepsis mortality for SOFA Scores higher than 6.

Assessing SOFA score trajectories in sepsis using machine learning: A pragmatic approach to improve the accuracy of mortality prediction

INTRODUCTION

An increasing amount of longitudinal health data is available on critically ill septic patients in the age of digital medicine, including daily sequential organ failure assessment (SOFA) score measurements. Thus, the assessment in sepsis focuses increasingly on the evaluation of the individual disease's trajectory. Machine learning (ML) algorithms may provide a promising approach here to improve the evaluation of daily SOFA score dynamics. We tested whether ML algorithms can outperform the conventional ΔSOFA score regarding the accuracy of 30-day mortality prediction.

METHODS

We used the multicentric SepsisDataNet.NRW study cohort that prospectively enrolled 252 sepsis patients between 03/2018 and 09/2019 for training ML algorithms, i.e. support vector machine (SVM) with polynomial kernel and artificial neural network (aNN). We used the Amsterdam UMC database covering 1,790 sepsis patients for external and independent validation.

RESULTS

Both SVM (AUC 0.84; 95% CI: 0.71-0.96) and aNN (AUC 0.82; 95% CI: 0.69-0.95) assessing the SOFA scores of the first seven days led to a more accurate prognosis of 30-day mortality compared to the ΔSOFA score between day 1 and 7 (AUC 0.73; 95% CI: 0.65-0.80; p = 0.02 and p = 0.05, respectively). These differences were even more prominent the shorter the time interval considered. Using the SOFA scores of day 1 to 3 SVM (AUC 0.82; 95% CI: 0.68 0.95) and aNN (AUC 0.80; 95% CI: 0.660.93) led to a more accurate prognosis of 30-day mortality compared to the ΔSOFA score (AUC 0.66; 95% CI: 0.58-0.74; p < 0.01 and p < 0.01, respectively). Strikingly, all these findings could be confirmed in the independent external validation cohort.

CONCLUSIONS

The ML-based algorithms using daily SOFA scores markedly improved the accuracy of mortality compared to the conventional ΔSOFA score. Therefore, this approach could provide a promising and automated approach to assess the individual disease trajectory in sepsis. These findings reflect the potential of incorporating ML algorithms as robust and generalizable support tools on intensive care units.

The Aquaporin 3 Polymorphism (rs17553719) Is Associated with Sepsis Survival and Correlated with IL-33 Secretion

Sepsis is a common life-threatening disease caused by dysregulated immune response and metabolic acidosis which lead to organ failure. An abnormal expression of aquaporins plays an important role in organ failure. Additionally, genetic variants in aquaporins impact on the outcome in sepsis. Thus, we investigated the polymorphism (rs17553719) and expression of aquaporin-3 (AQP3) and correlated these measurements with the survival of sepsis patients. Accordingly, we collected blood samples on several days (plus clinical data) from 265 sepsis patients who stayed in different ICUs in Germany. Serum plasma, DNA, and RNA were then separated to detect the promotor genotypes of AQP3 mRNA expression of AQP3 and several cytokines. The results showed that the homozygote CC genotype exhibited a significant decrease in 30-day survival (38.9%) compared to the CT (66.15%) and TT genotypes (76.3%) (p = 0.003). Moreover, AQP3 mRNA expression was significantly higher and nearly doubled in the CC compared to the CT (p = 0.0044) and TT genotypes (p = 0.018) on the day of study inclusion. This was accompanied by an increased IL-33 concentration in the CC genotype (day 0: p = 0.0026 and day 3: p = 0.008). In summary, the C allele of the AQP3 polymorphism (rs17553719) shows an association with increased AQP3 expression and IL-33 concentration accompanied by decreased survival in patients with sepsis.

AQP3 and AQP9-Contrary Players in Sepsis?

Sepsis involves an immunological systemic response to a microbial pathogenic insult, leading to a cascade of interconnected biochemical, cellular, and organ-organ interaction networks. Potential drug targets can depict aquaporins, as they are involved in immunological processes. In immune cells, AQP3 and AQP9 are of special interest. In this study, we tested the hypothesis that these aquaporins are expressed in the blood cells of septic patients and impact sepsis survival. Clinical data, routine laboratory parameters, and blood samples from septic patients were analyzed on day 1 and day 8 after sepsis diagnosis. AQP expression and cytokine serum concentrations were measured. AQP3 mRNA expression increased over the duration of sepsis and was correlated with lymphocyte count. High AQP3 expression was associated with increased survival. In contrast, AQP9 expression was not altered during sepsis and was correlated with neutrophil count, and low levels of AQP9 were associated with increased survival. Furthermore, AQP9 expression was an independent risk factor for sepsis lethality. In conclusion, AQP3 and AQP9 may play contrary roles in the pathophysiology of sepsis, and these results suggest that AQP9 may be a novel drug target in sepsis and, concurrently, a valuable biomarker of the disease.

Human cytomegalovirus seropositivity is associated with reduced patient survival during sepsis

BACKGROUND

Sepsis is one of the leading causes of death. Treatment attempts targeting the immune response regularly fail in clinical trials. As HCMV latency can modulate the immune response and changes the immune cell composition, we hypothesized that HCMV serostatus affects mortality in sepsis patients.

METHODS

We determined the HCMV serostatus (i.e., latency) of 410 prospectively enrolled patients of the multicenter SepsisDataNet.NRW study. Patients were recruited according to the SEPSIS-3 criteria and clinical data were recorded in an observational approach. We quantified 13 cytokines at Days 1, 4, and 8 after enrollment. Proteomics data were analyzed from the plasma samples of 171 patients.

RESULTS

The 30-day mortality was higher in HCMV-seropositive patients than in seronegative sepsis patients (38% vs. 25%, respectively; p = 0.008; HR, 1.656; 95% CI 1.135-2.417). This effect was observed independent of age (p = 0.010; HR, 1.673; 95% CI 1.131-2.477). The predictive value on the outcome of the increased concentrations of IL-6 was present only in the seropositive cohort (30-day mortality, 63% vs. 24%; HR 3.250; 95% CI 2.075-5.090; p < 0.001) with no significant differences in serum concentrations of IL-6 between the two groups. Procalcitonin and IL-10 exhibited the same behavior and were predictive of the outcome only in HCMV-seropositive patients.

CONCLUSION

We suggest that the predictive value of inflammation-associated biomarkers should be re-evaluated with regard to the HCMV serostatus. Targeting HCMV latency might open a new approach to selecting suitable patients for individualized treatment in sepsis.

Blood taken immediately after fatal resuscitation attempts yields higher quality DNA for genetic studies as compared to autopsy samples

BACKGROUND

The out-of-hospital cardiac arrest (OHCA) in the young may be associated with a genetic predisposition which is relevant even for genetic counseling of relatives. The identification of genetic variants depends on the availability of intact genomic DNA. DNA from autopsy may be not available due to low autopsy frequencies or not suitable for high-throughput DNA sequencing (NGS). The emergency medical service (EMS) plays an important role to save biomaterial for subsequent molecular autopsy. It is not known whether the DNA integrity of samples collected by the EMS is better suited for NGS than autopsy specimens.

MATERIAL AND METHODS

DNA integrity was analyzed by standardized protocols. Fourteen blood samples collected by the EMS and biomaterials from autopsy were compared. We collected 172 autopsy samples from different tissues and blood with postmortem intervals of 14-168 h. For comparison, DNA integrity derived from blood stored under experimental conditions was checked against autopsy blood after different time intervals.

RESULTS

DNA integrity and extraction yield were higher in EMS blood compared to any autopsy tissue. DNA stability in autopsy specimens was highly variable and had unpredictable quality. In contrast, collecting blood samples by the EMS is feasible and delivered comparably the highest DNA integrity.

CONCLUSIONS

Isolation yield and DNA integrity from blood samples collected by the EMS is superior in comparison to autopsy specimens. DNA from blood samples collected by the EMS on scene is stable at room temperature or even for days at 4 °C. We conclude that the EMS personnel should always save a blood sample of young fatal OHCA cases died on scene to enable subsequent genetic analysis.

Hemoadsorption in the critically ill-Final results of the International CytoSorb Registry

The aim of the current paper is to summarize the results of the International CytoSorb Registry. Data were collected on patients of the intensive care unit. The primary endpoint was actual in-hospital mortality compared to the mortality predicted by APACHE II score. The main secondary endpoints were SOFA scores, inflammatory biomarkers and overall evaluation of the general condition. 1434 patients were enrolled. Indications for hemoadsorption were sepsis/septic shock (N = 936); cardiac surgery perioperatively (N = 172); cardiac surgery postoperatively (N = 67) and "other" reasons (N = 259). APACHE-II-predicted mortality was 62.0±24.8%, whereas observed hospital mortality was 50.1%. Overall SOFA scores did not change but cardiovascular and pulmonary SOFA scores decreased by 0.4 [-0.5;-0.3] and -0.2 [-0.3;-0.2] points, respectively. Serum procalcitonin and C-reactive protein levels showed significant reduction: -15.4 [-19.6;-11.17] ng/mL; -17,52 [-70;44] mg/L, respectively. In the septic cohort PCT and IL-6 also showed significant reduction: -18.2 [-23.6;-12.8] ng/mL; -2.6 [-3.0;-2.2] pg/mL, respectively. Evaluation of the overall effect: minimal improvement (22%), much improvement (22%) and very much improvement (10%), no change observed (30%) and deterioration (4%). There was no significant difference in the primary outcome of mortality, but there were improvements in cardiovascular and pulmonary SOFA scores and a reduction in PCT, CRP and IL-6 levels. Trial registration: ClinicalTrials.gov Identifier: NCT02312024 (retrospectively registered).

Case report: Early detection of mesenteric ischemia by intravital microscopy in a patient with septic shock

Gut ischemia is a frequent but underdiagnosed complication, especially in critically ill intensive care patients, and represents a special diagnostic challenge that can only be solved in an interdisciplinary manner. We report a case of a 54-year-old woman with acute mesenteric ischemia (AMI) as a cause of septic shock diagnosed by intravital microscopy (IVM) 2 days before visible necrotic changes in a multimodality approach. We show that intravital microscopy can be a serious alternative for the early diagnosis of mesenteric ischemia in the hands of the skilled. We use this case to discuss the value and clinical perspective of IVM in the intensive care setting.

Lung-Protective Ventilation Attenuates Mechanical Injury While Hypercapnia Attenuates Biological Injury in a Rat Model of Ventilator-Associated Lung Injury

Background and Objective: Lung-protective mechanical ventilation is known to attenuate ventilator-associated lung injury (VALI), but often at the expense of hypoventilation and hypercapnia. It remains unclear whether the main mechanism by which VALI is attenuated is a product of limiting mechanical forces to the lung during ventilation, or a direct biological effect of hypercapnia.

Methods: Acute lung injury (ALI) was induced in 60 anesthetized rats by the instillation of 1.25 M HCl into the lungs via tracheostomy. Ten rats each were randomly assigned to one of six experimental groups and ventilated for 4 h with: 1) Conventional HighV_ENormocapnia (high V_T, high minute ventilation, normocapnia), 2) Conventional Normocapnia (high V_T, normocapnia), 3) Protective Normocapnia (V_T 8 ml/kg, high RR), 4) Conventional iCO₂Hypercapnia (high V_T, low RR, inhaled CO₂), 5) Protective iCO₂Hypercapnia (V_T 8 ml/kg, high RR, added CO₂), 6) Protective endogenous Hypercapnia (V_T 8 ml/kg, low RR). Blood gasses, broncho-alveolar lavage fluid (BALF), and tissue specimens were collected and analyzed for histologic and biologic lung injury assessment.

Results: Mild ALI was achieved in all groups characterized by a decreased mean PaO₂/FiO₂ ratio from 428 to 242 mmHg (p < 0.05), and an increased mean elastance from 2.46 to 4.32 cmH₂O/L (p < 0.0001). There were no differences in gas exchange among groups. Wet-to-dry ratios and formation of hyaline membranes were significantly lower in low V_T groups compared to conventional tidal volumes. Hypercapnia reduced diffuse alveolar damage and IL-6 levels in the BALF, which was also true when CO₂ was added to conventional V_T. In low V_T groups, hypercapnia did not induce any further protective effect except increasing pulmonary IL-10 in the BALF. No differences in lung injury were observed when hypercapnia was induced by adding CO₂ or decreasing minute ventilation, although permissive hypercapnia decreased the pH significantly and decreased liver histologic injury.

Conclusion: Our findings suggest that low tidal volume ventilation likely attenuates VALI by limiting mechanical damage to the lung, while hypercapnia attenuates VALI by limiting pro-inflammatory and biochemical mechanisms of injury. When combined, both lung-protective ventilation and hypercapnia have the potential to exert an synergistic effect for the prevention of VALI.

[Surgery in the balance between humanity, ethics and economics]

BACKGROUND

The economic pressure in the healthcare system has noticeably increased in the past few years. The manifestation of an "economization in medicine" development raises questions about the compatibility of physicians' duties and economic incentives in the healthcare system.

OBJECTIVE

Against this background the article analyzes areas of conflict in the German healthcare system and surgery in particular. The main questions focus on: what lines of conflict can arise between ethical duties and economic requirements and what possibilities for conflict resolution can provide orientation on the macrolevel and microlevel?

MATERIAL AND METHODS

The article is based on the analysis of normative regulations, guidelines and statements from the self-administrative institutions and multidisciplinary literature from medicine, medical ethics and health economics. Core issues in the conflict area between "humanity-ethics-economics" are structured and recommendations for action are derived.

RESULTS AND DISCUSSION

Superordinate regulatory framework conditions and their subsequent incentives must not conflict with the ethical principles of medical care, especially the primary orientation to patient welfare. Institutional and individual healthcare providers have a responsibility towards patients first and only secondarily for an economically appropriate spending of public resources. The provision of medical care for people must enable an adequate livelihood. Institutional maximization of profits is to be avoided, especially concerning financial investors. In the corona pandemic, economic disincentives are becoming apparent and necessitate readjustments. Possible recommendations for action are the empowerment of the medical profession and management to engage in a qualified exchange.

Therapeutic Modulation of the Host Defense by Hemoadsorption with CytoSorb®-Basics, Indications and Perspectives-A Scoping Review

The "normal" immune response to an insult triggers a highly regulated response determined by the interaction of various immunocompetent cells with pro- and anti-inflammatory cytokines. Under pathologic conditions, the massive elevation of cytokine levels ("cytokine storm") could not be controlled until the recent development of hemoadsorption devices that are able to extract a variety of different DAMPs, PAMPs, and metabolic products from the blood. CytoSorb® has been approved for adjunctive sepsis therapy since 2011. This review aims to summarize theoretical knowledge, in vitro results, and clinical findings to provide the clinician with pragmatic guidance for daily practice. English-language and peer-reviewed literature identified by a selective literature search in PubMed and published between January 2016 and May 2021 was included. Hemoadsorption can be used successfully as adjunct to a complex therapeutic regimen for various conditions. To the contrary, this nonspecific intervention may potentially worsen patient outcomes in complex immunological processes. CytoSorb® therapy appears to be safe and useful in various diseases (e.g., rhabdomyolysis, liver failure, or intoxications) as well as in septic shock or cytokine release syndrome, although a conclusive assessment of treatment benefit is not possible and no survival benefit has yet been demonstrated in randomized controlled trials.

Profound decrease of liver maximum function capacity test of isoflurane sedated patients: A report of three cases

LiMAx 13C-methacetin breath test results should be interpreted with caution in patients sedated with isoflurane.

The emergency medical service has a crucial role to unravel the genetics of sudden cardiac arrest in young, out of hospital resuscitated patients: Interim data from the MAP-IT study

BACKGROUND

Genetics of sudden cardiac deaths (SCD) remains frequently undetected. Genetic analysis is recommended in undefined selected cases in the 2021 ERC-guideline. The emergency medical service and physicians (EMS) may play a pivotal role for unraveling SCD by saving biomaterial for later molecular autopsy. Since for high-throughput DNA-sequencing (NGS) high quality genomic DNA is needed. We investigated in a prospective proof-of-concept study the role of the EMS for the identification of genetic forms of SCDs in the young.

METHODS

We included patients aged 1-50 years with need for cardiopulmonary resuscitation attempts (CPR). Cases with non-natural deaths were excluded. In two German counties with 562,904 residents 39,506 services were analysed. Paired end panel-sequencing was performed, and variants were classified according to guidelines of the American College of Medical Genetics (ACMG).

RESULTS

769 CPR-attempts were recorded (1.95% of all EMS-services; CPR-incidence 68/100,000). In 103 cases CPR were performed in patients < 50y. 58% died on scene, 26% were discharged from hospital. 24 subjects were included for genotyping. Of these 33% died on scene, 37.5% were discharged from hospital. 25% of the genotyped patients were carriers of (likely) pathogenic (ACMG-4/-5) variants. 67% carried variants with unknown significance (ACMG-3). 2 of them had familial history for arrhythmogenic cardiomyopathy or had to be re-classified as ACMG-4 carriers due to whole exome sequencing.

CONCLUSION

The EMS contributes especially in fatal OHCA-cases to increase the yield of identified genetic conditions by collecting a blood sample on scene. Thus, the EMS can contribute significantly to primary and secondary prophylaxis in affected families.

High-dose CytoSorb hemoadsorption is associated with improved survival in patients with septic shock: A retrospective cohort study

BACKGROUND AND PURPOSE

Hemoadsorption with CytoSorb® offers a possible therapeutic approach in septic shock, but modes of application and dosing are still undetermined.

MATERIALS AND METHODS

Data from surgical patients with septic shock, treated with hemoadsorption adjunctive to renal replacement therapy were analyzed retrospectively. The 28-day mortality was compared to predicted mortality.

RESULTS

In 70 patients (70.6 ± 13.3 years), hemoadsorption was applied for 85.6 ± 53.8 h. The APACHE ll (30.2 ± 6.3) calculated to a predicted mortality of 73.3%, while the observed mortality was significantly lower (50%, p < 0.05). The amount of blood purified was higher in survivors than in non-survivors (8.5 ± 4.4 vs. 6.1 ± 3.6 l/kgBW, p = 0.017). We identified three clusters of <6 l/kgBW, 6-13 l/kgBW and ≥ 13 l/kgBW with a linear dose-response relation between blood purification volume and survival, which was best in the highest volume cluster (83.3%; p = 0.045).

CONCLUSIONS

The application of CytoSorb® seems to be effective in various conditions of septic shock. In a cohort of most severely ill patients the observed mortality was lower than predicted and decreased linearly with blood purification volumes inadvertently exceeding 6 l/kg BW. These results suggest that hemoadsorption might improve survival provided that the applied dose is high enough.

Implementation of anesthesia quality indicators in Germany : A prospective, national, multicenter quality improvement study

BACKGROUND

In 2016 the German Society of Anesthesiology and Intensive Care Medicine (DGAI) and the Association of German Anesthetists (BDA) published 10 quality indicators (QI) to compare and improve the quality of anesthesia care in Germany. So far, there is no evidence for the feasibility of implementation of these QI in hospitals.

OBJECTIVE

This study tested the hypothesis that the implementation of the 10 QI is feasible in German hospitals.

MATERIAL AND METHODS

This prospective three-phase national multicenter quality improvement study was conducted in 15 German hospitals and 1 outpatient anesthesia center from March 2017 to February 2018. The trial consisted of an initial evaluation of pre-existing structures and processes by the heads of the participating anesthesia departments, followed by a 6-month implementation phase of the QI as well as a final re-evaluation phase. The implementation procedure was supported by web-based implementation aids ( www.qi-an.org ) and internal quality management programs. The primary endpoint was the difference in the number of implemented QI per center before and after implementation. Secondary endpoints were the number of newly implemented QI per center, the overall number of successful implementations of each QI, the identification of problems during the implementation as well as the kind of impediments preventing the QI implementation.

RESULTS

The average number of implemented QI increased from 5.8 to 6.8 (mean of the differences 1.1 ± 1.3; P < 0.01). Most frequently the QI perioperative morbidity and mortality report (5 centers) and the QI temperature management (4 centers) could be implemented. After the implementation phase, the QI incidence management and patient blood management were implemented in all 16 centers. Implementation of other quality indicators failed mainly due to a lack of time and lack of structural resources.

CONCLUSION

In this study the implementation of QI was proven to be mostly feasible in the participating German hospitals. Although several QI could be implemented with minor effort, more time, financial and structural resources would be required for some QI, such as the QI postoperative visit.

[Implementation of anesthesia quality indicators in Germany : A prospective, national, multicenter quality improvement study]

BACKGROUND

In 2016 the German Society of Anesthesiology and Intensive Care Medicine (DGAI) and the Association of German Anesthetists (BDA) published 10 quality indicators (QI) to compare and improve the quality of anesthesia care in Germany. So far, there is no evidence for the feasibility of implementation of these QI in hospitals.

OBJECTIVE

This study tested the hypothesis that the implementation of the 10 QI is feasible in German hospitals.

MATERIAL AND METHODS

This prospective three-phase national multicenter quality improvement study was conducted in 15 German hospitals and 1 outpatient anesthesia center from March 2017 to February 2018. The trial consisted of an initial evaluation of pre-existing structures and processes by the heads of the participating anesthesia departments, followed by a 6-month implementation phase of the QI as well as a final re-evaluation phase. The implementation procedure was supported by web-based implementation aids ( www.qi-an.org ) and internal quality management programs. The primary endpoint was the difference in the number of implemented QI per center before and after implementation. Secondary endpoints were the number of newly implemented QI per center, the overall number of successful implementations of each QI, the identification of problems during the implementation as well as the kind of impediments preventing the QI implementation.

RESULTS

The average number of implemented QI increased from 5.8 to 6.8 (mean of the differences 1.1 ± 1.3; P < 0.01). Most frequently the QI perioperative morbidity and mortality report (5 centers) and the QI temperature management (4 centers) could be implemented. After the implementation phase, the QI incidence management and patient blood management were implemented in all 16 centers. Implementation of other quality indicators failed mainly due to a lack of time and lack of structural resources.

CONCLUSION

In this study the implementation of QI was proven to be mostly feasible in the participating German hospitals. Although several QI could be implemented with minor effort, more time, financial and structural resources would be required for some QI, such as the QI postoperative visit.

Increased effort during partial ventilatory support is not associated with lung damage in experimental acute lung injury

BACKGROUND

An on-going debate exists as to whether partial ventilatory support is lung protective in an acute phase of ARDS. So far, the effects of different respiratory efforts on the development of ventilator-associated lung injury (VALI) have been poorly understood. To test the hypothesis whether respiratory effort itself promotes VALI, acute lung injury (ALI) was induced in 48 Sprague Dawley rats by hydrochloric acid aspiration model. Hemodynamics, gas-exchange, and respiratory mechanics were measured after 4 h of ventilation in pressure control (PC), assist-control (AC), or pressure support with 100% (PS100), 60% (PS60), or 20% (PS20) of the driving pressure during PC. VALI was assessed by histological analysis and biological markers.

RESULTS

ALI was characterized by a decrease in PaO₂/FiO₂ from 447 ± 75 to 235 ± 90 mmHg (p < 0.001) and dynamic respiratory compliance from 0.53 ± 0.2 to 0.28 ± 0.1 ml/cmH₂O (p < 0.001). There were no differences in hemodynamics or respiratory function among groups at baseline or after 4 h of ventilation. The reduction of mechanical pressure support was associated with a compensatory increase in an inspiratory effort such that peak inspiratory transpulmonary pressures were equal in all groups. The diffuse alveolar damage score showed significant lung injury but was similar among groups. Pro- and anti-inflammatory proteins in the bronchial fluid were comparable among groups.

CONCLUSIONS

In experimental ALI in rodents, the respiratory effort was increased by reducing the pressure support during partial ventilatory support. In the presence of a constant peak inspiratory transpulmonary pressure, an increased respiratory effort was not associated with worsening ventilator-associated lung injury measured by histologic score and biologic markers.

Improve hip fracture outcome in the elderly patient (iHOPE): a study protocol for a pragmatic, multicentre randomised controlled trial to test the efficacy of spinal versus general anaesthesia

INTRODUCTION

Hip fracture surgery is associated with high in-hospital and 30-day mortality rates and serious adverse patient outcomes. Evidence from randomised controlled trials regarding effectiveness of spinal versus general anaesthesia on patient-centred outcomes after hip fracture surgery is sparse.

METHODS AND ANALYSIS

The iHOPE study is a pragmatic national, multicentre, randomised controlled, open-label clinical trial with a two-arm parallel group design. In total, 1032 patients with hip fracture (>65 years) will be randomised in an intended 1:1 allocation ratio to receive spinal anaesthesia (n=516) or general anaesthesia (n=516). Outcome assessment will occur in a blinded manner after hospital discharge and inhospital. The primary endpoint will be assessed by telephone interview and comprises the time to the first occurring event of the binary composite outcome of all-cause mortality or new-onset serious cardiac and pulmonary complications within 30 postoperative days. In-hospital secondary endpoints, assessed via in-person interviews and medical record review, include mortality, perioperative adverse events, delirium, satisfaction, walking independently, length of hospital stay and discharge destination. Telephone interviews will be performed for long-term endpoints (all-cause mortality, independence in walking, chronic pain, ability to return home cognitive function and overall health and disability) at postoperative day 30±3, 180±45 and 365±60. ETHICS AND DISSEMINATION: iHOPE has been approved by the leading Ethics Committee of the Medical Faculty of the RWTH Aachen University on 14 March 2018 (EK 022/18). Approval from all other involved local Ethical Committees was subsequently requested and obtained. Study started in April 2018 with a total recruitment period of 24 months. iHOPE will be disseminated via presentations at national and international scientific meetings or conferences and publication in peer-reviewed international scientific journals.

TRIAL REGISTRATION NUMBER

DRKS00013644; Pre-results.

Microcirculation measurements: Barriers for use in clinical routine

BACKGROUND

In patients with shock, inflammation and sepsis alterations in microcirculation are common problems. Although the pathophysiologic consequences are well understood, measurements of microcirculation have not entered clinical routine so far.

OBJECTIVE

To characterize the requirements for clinical microcirculation measurement techniques and the barriers for implementation into routine practice.

METHODS

Clinical review of reliability, reproducibility, validity, availability and usefulness of clinically available measurement techniques to be used in patients with sepsis or cardiac surgery with cardiopulmonary bypass.

RESULTS

Few methods such as video microscopy are readily available at the bedside, but are hampered by the high variability of measurements and the lack of reliable automated software analysis. The correlation of microcirculation impairment measured by in-vivo microscopy with fatal outcomes has been established, but no recommendations have been given which parameters should be targeted to improve outcomes. Measurement of regional brain tissue oxygenation has been recommended for cardiac surgery, but does not specifically target microcirculation.

CONCLUSIONS

International guidelines for the management of sepsis or cardiac anesthesia do not recommend specific goals targeting the microcirculation directly, but global hemodynamics. The reason for this may be attributed to the lack of methods that fulfill the requirements necessary to be clinically acceptable. Once the validity, i.e. any improvement in patient's outcomes attributable to microcirculation measurements, can be established, clinical measurement of microcirculation could become part of routine treatment of patients with sepsis, inflammation and shock. Until then, more clinical studies targeting microcirculation are urgently needed.

End-of-life perceptions among physicians in intensive care units managed by anesthesiologists in Germany: a survey about structure, current implementation and deficits

Background

Structural aspects and current practice about end-of-life (EOL) decisions in German intensive care units (ICUs) managed by anesthesiologists are unknown. A survey among intensive care anesthesiologists has been conducted to explore current practice, barriers and opinions on EOL decisions in ICU.

Methods

In November 2015, all members of the German Society of Anesthesiology and Intensive Care Medicine (DGAI) and the Association of German Anesthesiologists (BDA) were asked to participate in an online survey to rate the presence or absence and the importance of 50 items. Answers were grouped into three categories considering implementation and relevance: Category 1 reflects high implementation and high relevance, Category 2 low and low, and Category 3 low and high.

Results

Five-hundred and forty-one anesthesiologists responded. Only four items reached ≥90% agreement as being performed “yes, always” or “mostly”, and 29 items were rated “very” or “more important”. A profound discrepancy between current practice and attributed importance was revealed. Twenty-eight items attributed to Category 1, six to Category 2 and sixteen to Category 3. Items characterizing the most urgent need for improvement (Category 3) referred to patient outcome data, preparation of health care directives and interdisciplinary discussion, standard operating procedures, implementation of practical instructions and inclusion of nursing staff and families in the process.

Conclusion

The present survey affirms an urgent need for improvement in EOL practice in German ICUs focusing on advanced care planning, distinct aspects of changing goals of care, implementation of standard operating procedures, continuing education and reporting of outcome data.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-017-0384-5) contains supplementary material, which is available to authorized users.

Outcome of acute respiratory distress syndrome in university and non-university hospitals in Germany

Background

This study investigates differences in treatment and outcome of ventilated patients with acute respiratory distress syndrome (ARDS) between university and non-university hospitals in Germany.

Methods

This subanalysis of a prospective, observational cohort study was performed to identify independent risk factors for mortality by examining: baseline factors, ventilator settings (e.g., driving pressure), complications, and care settings—for example, case volume of ventilated patients, size/type of intensive care unit (ICU), and type of hospital (university/non-university hospital). To control for potentially confounding factors at ARDS onset and to verify differences in mortality, ARDS patients in university vs non-university hospitals were compared using additional multivariable analysis.

Results

Of the 7540 patients admitted to 95 ICUs from 18 university and 62 non-university hospitals in May 2004, 1028 received mechanical ventilation and 198 developed ARDS. Although the characteristics of ARDS patients were very similar, hospital mortality was considerably lower in university compared with non-university hospitals (39.3% vs 57.5%; p = 0.012). Treatment in non-university hospitals was independently associated with increased mortality (OR (95% CI): 2.89 (1.31–6.38); p = 0.008). This was confirmed by additional independent comparisons between the two patient groups when controlling for confounding factors at ARDS onset. Higher driving pressures (OR 1.10; 1 cmH₂O increments) were also independently associated with higher mortality. Compared with non-university hospitals, higher positive end-expiratory pressure (PEEP) (mean ± SD: 11.7 ± 4.7 vs 9.7 ± 3.7 cmH₂O; p = 0.005) and lower driving pressures (15.1 ± 4.4 vs 17.0 ± 5.0 cmH₂O; p = 0.02) were applied during therapeutic ventilation in university hospitals, and ventilation lasted twice as long (median (IQR): 16 (9–29) vs 8 (3–16) days; p < 0.001).

Conclusions

Mortality risk of ARDS patients was considerably higher in non-university compared with university hospitals. Differences in ventilatory care between hospitals might explain this finding and may at least partially imply regionalization of care and the export of ventilatory strategies to non-university hospitals.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1687-0) contains supplementary material, which is available to authorized users.

[Positioning therapy and early mobilization in intensive care units : Findings from the current 2015 guidelines]

The 2007 guidelines "Positioning for prophylaxis and therapy of pulmonary disorders" were completely revised in 2015 on behalf of the German Society of Anaesthesiology and Intensive Care Medicine. With regard to practical and scientific relevance, early mobilization of patients in critical care has been included in the guidelines for the first time. Furthermore, the recommendations for prone positioning have been updated, based on current evidence in medicine and nursing. In addition, recommendations regarding unsuitable positions that may actually harm patients were made. As such, the flat supine position should only be used in cases of urgent medical or nursing needs. This underlines the importance of a moderately elevated head of bed position (20(o)-45(o)) in mechanically ventilated patients.

[Short version S2e guidelines: "Positioning therapy and early mobilization for prophylaxis or therapy of pulmonary function disorders"]

The German Society of Anesthesiology and Intensive Care Medicine (DGAI) commissioned a revision of the S2 guidelines on "positioning therapy for prophylaxis or therapy of pulmonary function disorders" from 2008. Because of the increasing clinical and scientific relevance the guidelines were extended to include the issue of "early mobilization" and the following main topics are therefore included: use of positioning therapy and early mobilization for prophylaxis and therapy of pulmonary function disorders, undesired effects and complications of positioning therapy and early mobilization as well as practical aspects of the use of positioning therapy and early mobilization. These guidelines are the result of a systematic literature search and the subsequent critical evaluation of the evidence with scientific methods. The methodological approach for the process of development of the guidelines followed the requirements of evidence-based medicine, as defined as the standard by the Association of the Scientific Medical Societies in Germany. Recently published articles after 2005 were examined with respect to positioning therapy and the recently accepted aspect of early mobilization incorporates all literature published up to June 2014.

S2e guideline: positioning and early mobilisation in prophylaxis or therapy of pulmonary disorders : Revision 2015: S2e guideline of the German Society of Anaesthesiology and Intensive Care Medicine (DGAI)

The German Society of Anesthesiology and Intensive Care Medicine (DGAI) commissioneda revision of the S2 guidelines on "positioning therapy for prophylaxis or therapy of pulmonary function disorders" from 2008. Because of the increasing clinical and scientificrelevance the guidelines were extended to include the issue of "early mobilization"and the following main topics are therefore included: use of positioning therapy and earlymobilization for prophylaxis and therapy of pulmonary function disorders, undesired effects and complications of positioning therapy and early mobilization as well as practical aspects of the use of positioning therapy and early mobilization. These guidelines are the result of a systematic literature search and the subsequent critical evaluation of the evidence with scientific methods. The methodological approach for the process of development of the guidelines followed the requirements of evidence-based medicine, as defined as the standard by the Association of the Scientific Medical Societies in Germany. Recently published articles after 2005 were examined with respect to positioning therapy and the recently accepted aspect of early mobilization incorporates all literature published up to June 2014.

Partial ventilatory support modalities in acute lung injury and acute respiratory distress syndrome-a systematic review

PURPOSE

The efficacy of partial ventilatory support modes that allow spontaneous breathing in patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) is unclear. The objective of this scoping review was to assess the effects of partial ventilatory support on mortality, duration of mechanical ventilation, and both hospital and intensive care unit (ICU) lengths of stay (LOS) for patients with ALI and ARDS; the secondary objective was to describe physiologic effects on hemodynamics, respiratory system and other organ function.

METHODS

MEDLINE (1966-2009), Cochrane, and EmBase (1980-2009) databases were searched using common ventilator modes as keywords and reference lists from retrieved manuscripts hand searched for additional studies. Two researchers independently reviewed and graded the studies using a modified Oxford Centre for Evidence-Based Medicine grading system. Studies in adult ALI/ARDS patients were included for primary objectives and pre-clinical studies for supporting evidence.

RESULTS

Two randomized controlled trials (RCTs) were identified, in addition to six prospective cohort studies, one retrospective cohort study, one case control study, 41 clinical physiologic studies and 28 pre-clinical studies. No study was powered to assess mortality, one RCT showed shorter ICU length of stay, and the other demonstrated more ventilator free days. Beneficial effects of preserved spontaneous breathing were mainly physiological effects demonstrated as improvement of gas exchange, hemodynamics and non-pulmonary organ perfusion and function.

CONCLUSIONS

The use of partial ventilatory support modalities is often feasible in patients with ALI/ARDS, and may be associated with short-term physiological benefits without appreciable impact on clinically important outcomes.

Using remifentanil in mechanically ventilated rats to provide continuous analgosedation

Remifentanil is a potent synthetic opioid with sedative effects. Intravenous remifentanil provides deep sedation and analgesia in laboratory animals during experimental procedures. We hypothesized that remifentanil would provide effective analgosedation during assisted mechanical ventilation without affecting respiratory mechanics in rats. Five male Sprague- Dawley rats (weight, 400 to 450 g) were assigned to receive assisted mechanical ventilation with continuous positive airway pressure for 5 h. Remifentanil (0.4 μg/kg/min IV) was delivered for the duration of ventilation. There were no differences between baseline, 1 h, and 5 h of ventilation in the mean arterial pressure, cardiac output, heart rate, and body temperature of all rats. Similarly, no differences were observed in the tidal volume, respiratory rate and minute ventilation, and gas exchange was equal in all rats at all time points. Frequent assessment of sedation by toe pinch documented loss of the pedal withdrawal reflex in all rats. We conclude that continuous remifentanil infusion provides sufficient analgosedation for mechanically ventilated rats without compromising hemodynamics, respiratory function, or gas exchange.

Effects of hypercapnia and hypercapnic acidosis on attenuation of ventilator-associated lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are associated with impaired gas exchange, severe inflammation and alveolar damage including cell death. Patients with ALI or ARDS typically experience respiratory failure and thus require mechanical ventilation for support, which itself can aggravate lung injury. Recent developments in this field have revealed several therapeutic strategies that improve gas exchange, increase survival and minimize the deleterious effects of mechanical ventilation. Among those strategies is the reduction in tidal volume and allowing hypercapnia to develop during ventilation, or actively inducing hypercapnia. Here, we provide an overview of hypercapnia and the hypercapnic acidosis that typically follows, as well as the therapeutic effects of hypercapnia and acidosis in clinical studies and experimental models of ALI. Specifically, we review the effects of hypercapnia and acidosis on the attenuation of pulmonary inflammation, reduction of apoptosis in alveolar epithelial cells, improvement in sepsis-induced ALI and the therapeutic effects on other organ systems, as well as the potentially harmful effects of these strategies. The clinical implications of hypercapnia and hypercapnic acidosis are still not entirely clear. However, future research should focus on the intracellular signaling pathways that mediate ALI development, potentially focusing on the role of reactive biological species in ALI pathogenesis. Future research can also elucidate how such pathways may be targeted by hypercapnia and hypercapnic acidosis to attenuate lung injury.

Physiologic and biologic characteristics of three experimental models of acute lung injury in rats

BACKGROUND

Strategies to attenuate ventilator-associated lung injury have been tested in various experimental methods of acute lung injury (ALI). Conclusions are often drawn from physiologic and biologic effects, but the influence of the model on these results is not known. Our aim in this study was to characterize frequently used models of experimental ALI.

METHODS

Twenty Sprague Dawley rats were anesthetized and their lungs mechanically ventilated for 5 hours. Three models of ALI (surfactant washout, acid aspiration, and high tidal volume ventilation) were investigated with regard to hemodynamics, respiratory mechanics, gas exchange, lung pathology, and inflammatory reactions. Animals without ALI served as controls.

RESULTS

Five animals in each group were analyzed. Dynamic compliance and Pao(2)/fraction of inspired oxygen ratio decreased by at least 50% in all groups after 1 hour. Whereas compliance remained decreased in all models, oxygenation returned to baseline values in the lavage group after 5 hours. Diffuse alveolar damage was worse in the high tidal volume model and was not different between the control and lavage animals. Interleukin-6 was increased in bronchoalveolar lavage fluid in the aspiration and high tidal volume models.

CONCLUSIONS

Although comparable physiologic effects meeting acute respiratory distress syndrome criteria were achieved in all models, the biologic responses varied among lung injury models. The acid aspiration model created both respiratory and inflammatory responses typically seen in ALI; these data suggest that it may be the most clinically applicable model to study the intermediate-term effects of ventilator-associated lung injury in rats.

What on earth is APRV?

Partial ventilatory support modalities are ill defined and different perceptions about these modes might depend on geographic region. Exemplary on two recent publications investigating airway pressure release ventilation (APRV) in an adult ICU population, the question is investigated whether research in ventilation modes can be performed with the current definitions. The lack of precise definitions precludes drawing meaningful conclusions from these studies, as it remains unclear how these patients were actually ventilated and whether or how much spontaneous breathing was factitiously preserved. An argument is made to develop a new taxonomy of ventilation modes.

Case study of hepatic radiofrequency ablation causing a systemic inflammatory response under total intravenous anesthesia

Objective

To investigate the effects of hepatic radiofrequency ablation (RFA) in patients with malignant liver disease with respect to inflammation activation and stress response.

Materials and Methods

In an observational trial, we investigated the physiologic parameters of 17 patients (20 interventions) who underwent percutaneous RFA under general anesthesia after applying total intravenous anesthesia. TNFα, IL-6, IL-8, IL-10, adrenaline and noradrenaline, liver enzymes, lactate and creatine kinase were determined pre-interventionally after induction of anesthesia (T1), 90 minutes after initiation of RFA (T2), immediately after the conclusion of the procedure (T3), and 24 hours after the procedure (T4).

Results

A significant increase in body temperature (p < 0.001), and mean arterial pressure (p = 0.001) were measured intraoperatively (T2) and the day after the procedure (T4). Increased levels of IL-6 were measured at T3 and T4 (p = 0.001). IL-10 increased immediately after the procedure (T3; p = 0.007). IL-6 levels correlated well with the total energy applied (r = 0.837). Significant increases in the levels of adrenaline and noradrenaline were present at T3 and T4 (p < 0.001). The RFA-induced destruction of hepatic tissue was associated with increased levels of AST, ALT, GLDH and LDH.

Conclusion

Percutaneous RFA of hepatic malignancies causes an inflammatory and endocrine activation, similar to the systemic inflammatory response syndrome. These effects have to be taken in account when dealing with patients susceptible to sepsis or multi-organ failure.

Effects of different fibrinogen concentrations on blood loss and coagulation parameters in a pig model of coagulopathy with blunt liver injury

INTRODUCTION

The early application of fibrinogen could potentially reverse haemodilution-induced coagulopathy, although the impact of varying concentrations of fibrinogen to reverse dilutional coagulopathy has not been studied in vivo. We postulated that fibrinogen concentration is correlated with blood loss in a pig model of coagulopathy with blunt liver injury.

METHODS

Coagulopathy was induced in 18 anaesthetized pigs (32 +/- 1.6 kg body weight) by replacing 80% of blood volume with hydroxyethylstarch 130/0.4 and Ringer's lactated solution, and re-transfusion of erythrocytes. Animals were randomly assigned to receive either 70 mg kg-1 (F-70) or 200 mg kg-1 (F-200) fibrinogen or placebo before inducing blunt liver injury using a force of 225 +/- 26 Newton. Haemodynamics, coagulation parameters and blood loss were monitored for 2 hours. After death, histological examination of internal organs was performed to assess the presence of emboli and the equality of liver injury.

RESULTS

Plasma dilution caused severe coagulopathy. Measured by thromboelastography fibrinogen restored coagulation dose-dependently. Total blood loss was significantly lower and survival better in both fibrinogen groups as compared to controls (P < 0.05). Between the F-70 (1317 +/- 113 ml) and the F-200 group (1155 +/- 232 ml) no significant difference in total blood loss could be observed, despite improved coagulation parameters in the F-200 group (P < 0.05). Microscopy revealed even injury pattern and no (micro) thrombi for either group.

CONCLUSIONS

Restoring fibrinogen with 70 or 200 mg kg-1 after severe dilutional coagulopathy safely improved coagulation and attenuated blood loss after experimental blunt liver trauma. The higher dosage of fibrinogen was not associated with a further reduction in blood loss.

Effects of preserved spontaneous breathing activity during mechanical ventilation in experimental intra-abdominal hypertension

PURPOSE

Ventilation problems are common in critically ill patients with intra-abdominal hypertension. The aim of this study was to investigate the effects of preserved spontaneous breathing during mechanical ventilation on hemodynamics, gas exchange, respiratory function and lung injury in experimental intra-abdominal hypertension.

METHODS

Twenty anesthetized pigs were intubated and ventilated for 24 h with biphasic positive airway pressure without (BIPAP(PC)) or with additional, unsynchronized spontaneous breathing (BIPAP(SB)). In 12 animals, intra-abdominal pressure was increased to 30 mmHg for two 9 h periods followed by a 3 h pressure relief each. Eight animals served as controls and were ventilated for 24 h. Hemodynamics, gas exchange and respiratory mechanics were measured and lung injury was determined histologically.

RESULTS

Intra-abdominal hypertension caused significant impairment of hemodynamics and respiratory mechanics in both modes. In the presence of intra-abdominal hypertension, BIPAP(SB) did not demonstrate superior respiratory mechanics and cardiovascular stability as compared to BIPAP(PC). Although the decrease of dynamic compliance and the increase of airway pressures were mitigated, BIPAP(SB) failed to lower pulmonary vascular resistance and caused increased dead space ventilation (p = 0.007). Blood pressures and cardiac output increased in BIPAP(SB), caused by an increase in heart rate (p < 0.001), but not in stroke volume (p = 0.06). BIPAP(SB) was associated with an increased breathing effort, decreased transpulmonary pressure during inspiration and lower lobe diffuse alveolar damage (p = 0.002).

CONCLUSIONS

In the presence of severe intra-abdominal hypertension, the addition of unsupported spontaneous breaths to BIPAP did not improve hemodynamic and respiratory function and caused greater histopathologic damage to the lungs.

Comparison of arterial pressure cardiac output monitoring with transpulmonary thermodilution in septic patients

BACKGROUND

The measurement of cardiac output in critically ill patients is complicated by rapid pathophysiological changes. The aim of this study was to compare the recently developed Arterial Pressure Cardiac Output algorithm (APCO) with transpulmonary thermodilution (TDCO). Clinical and hemodynamic parameters were tested for their impact on the measurements.

MATERIAL/METHODS

Twenty septic patients were examined. Cardiac output measurements were performed simultaneously on 3 consecutive days. The data were evaluated using regression analysis and the Bland Altman approach.

RESULTS

Bland Altman analysis presented a bias of 0.72 L/min and limits of agreement of 2.16 to 3.61 L/min for TDCO vs. APCO. Statistically significant covariables in the regression analysis were systemic vascular resistance (p<0.001), mean arterial pressure (p<0.001), cardiac function index (p=0.01), global end-diastolic index (p=0.02) and stroke volume index (p=0.005). Multiple linear regression analysis showed the residual percentage error decreased from 49.1% to 21.5%.

CONCLUSIONS

The APCO algorithm provides a broad range of hemodynamic measurements with a minimally invasive approach and simple access to the patient's hemodynamic state. However, an underestimation at high cardiac output and an overestimation at low cardiac output relative to transpulmonary thermodilution were observed in septic patients. Therefore, the APCO algorithm in its current state cannot be substituted for transpulmonary thermodilution.

[Airway management]

Managing the difficult airway poses an enormous challenge for anaesthesiologists, intensivists and A&E physicians, particularly because of the high probability of a potentially fatal outcome. Development and (pre-) clinical distribution of supraglottic airway devices (e.g. LMA, LT) and their enhancements, as well as the broad acceptance of awake fibre-optic intubation, led to a profound change in the strategy for managing the difficult airway. This is reflected in the revised ASA guidelines, implementing the use of the laryngeal mask airway and fibre-optic intubation. In view of the utmost importance of this topic the German Society of Anaesthesiology and Intensive Care Medicine (DGAI) framed an independent German guideline, considering German national terms and conditions. In analogy algorithms and guidelines of the ILCOR, ERC and ATLS were revised as well as those of many other national anaesthesiological boards. Nevertheless, massive national and international deficits exist in implementing these guidelines into practice and the implicated structural requirements with respect to education, reflection, team building and equipment concerning the individual institution.

Parameters derived from the pulmonary pressure volume curve, but not the pressure time curve, indicate recruitment in experimental lung injury

BACKGROUND

In acute lung injury, ventilation avoiding tidal hyperinflation and tidal recruitment has been proposed to prevent ventilator-associated lung injury. Information about dynamic recruitment may be obtained from the characteristics of pressure-volume (PV) curves or the profile of pressure-time (Paw-t) curves.

METHODS

Six anesthetized pigs with lung lavage-induced acute lung injury were ventilated with lung-protective settings. We measured the effects of a standard recruitment maneuver on hysteresis area and ratio obtained from the PV curve and on the stress index obtained from the Paw-t curve and correlated this with aerated and nonaerated lung volumes as measured by multislice computed tomography.

RESULTS

Hysteresis area and ratio correlated with aerated lung volume (r = 0.886). The recruitment maneuver resulted in an increase in aerated (+12%) and a decrease (-18%) in nonaerated lung. Hysteresis area correlated with alveolar recruitment, represented by an increase in aerated lung (r = 0.886) and a decrease in nonaerated lung (r = -0.829) during tidal ventilation. The stress index was always >1 and indicated tidal hyperinflation only. Values did not change after the recruitment maneuver and did not correlate with any other lung volume.

CONCLUSIONS

Parameters derived from the PV curve may help in characterizing the lung aeration of the lung and in indicating recruitment. In the presence of lung-protective ventilator settings, the stress index derived from the Paw-t curve was not able to indicate recruitment.

Use of blood and blood products in trauma

According to the global study of the burden of disease, violence and accidental injury account for 12% of deaths worldwide; 30-40% of trauma mortality is attributable to haemorrhage. The highly complex haemostatic system is severely impaired as a result of haemorrhagic shock, acidosis, hypothermia, haemodilution, hyperfibrinolysis, and consumption of clotting factors. Thus it is important to prioritize the prevention of the development of coagulopathy. Timely transfusion of red blood cells and plasma products becomes essential to restore tissue oxygenation, support perfusion, and maintain the pool of active haemostatic factors. The limits to this strategy to compensate for the loss of blood and coagulation factors are discussed. In the absence of international guidelines, there is an ongoing debate about a generally accepted treatment algorithm, mass transfusion protocols, and adverse events that have been observed as a result of transfusion. Thus many recommendations are based upon expert opinion rather than on evidence. In this chapter we address key issues of transfusions of red blood cells and plasma products in the acute control of bleeding in traumatized patients.

Early modifiable factors associated with fatal outcome in patients with severe traumatic brain injury: a case control study

OBJECTIVE

Survival of patients with severe traumatic brain injury may be improved by minimizing secondary brain injury. We aimed to identify potentially modifiable contributors to secondary brain injury that may persist and adversely affect patient outcome.

DESIGN

Retrospective case control study. Nonsurviving patients with traumatic brain injury were selected and matched 1:1 for age, Glasgow Coma Scale score, Abbreviated Injury Scale: Head (AISHEAD), Revised Trauma Score, and Injury Severity Score with survivors. Potentially modifiable contributors to secondary brain injury were examined and compared in both groups.

SETTING

A level I trauma center in Melbourne, Australia.

PATIENTS

Patients with traumatic brain injury caused by blunt trauma with an AISHEAD >or=4 were identified from a prospective intensive care database.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Between January 1, 1999, and July 30, 2000, 74 patients, including 37 nonsurvivors, were identified. By design, the groups were well matched for injury severity and baseline conditions. In nonsurvivors, mean arterial pressure was similar to that of survivors at hospital arrival but was lower at 4 hrs after arrival (71 +/- 16 vs. 80 +/- 15 mm Hg, p = .016). A mean arterial pressure <or=65 mm Hg during this 4-hr period was associated with a four-fold increase in the odds of nonsurvival (95% confidence interval, 1.25-12.8). Intracranial pressure monitoring and intensive care unit admission tended to be initiated later in nonsurvivors, potentially delaying recognition and management of inadequate cerebral perfusion pressure. In nonsurvivors, hypothermia did not normalize during the first 24 hrs after injury.

CONCLUSIONS

In patients with severe traumatic brain injury, lower blood pressure in the first 4 hrs after admission was associated with mortality and may have increased the rate of secondary brain injury. Outcomes of patients with severe traumatic brain injury may potentially be improved by early targeting of the higher mean arterial pressure observed in survivors (mean arterial pressure 80 mm Hg), which may facilitate improved cerebral perfusion. Slower initiation of intracranial pressure monitoring and of intensive care unit admission may also have adversely affected outcomes, whereas persistent hypothermia was associated with nonsurvival.