The Effect of Targeted Hyperoxemia on Brain Immunohistochemistry after Long-Term, Resuscitated Porcine Acute Subdural Hematoma and Hemorrhagic Shock.

Epidemiological data suggest that moderate hyperoxemia may be associated with an improved outcome after traumatic brain injury. In a prospective, randomized investigation of long-term, resuscitated acute subdural hematoma plus hemorrhagic shock (ASDH + HS) in 14 adult, human-sized pigs, targeted hyperoxemia (200 < PaO2 < 250 mmHg vs. normoxemia 80 < PaO2 < 120 mmHg) coincided with improved neurological function. Since brain perfusion, oxygenation and metabolism did not differ, this post hoc study analyzed the available material for the effects of targeted hyperoxemia on cerebral tissue markers of oxidative/nitrosative stress (nitrotyrosine expression), blood-brain barrier integrity (extravascular albumin accumulation) and fluid homeostasis (oxytocin, its receptor and the H2S-producing enzymes cystathionine-ß-synthase and cystathionine-γ-lyase). After 2 h of ASDH + HS (0.1 mL/kgBW autologous blood injected into the subdural space and passive removal of 30% of the blood volume), animals were resuscitated for up to 53 h by re-transfusion of shed blood, noradrenaline infusion to maintain cerebral perfusion pressure at baseline levels and hyper-/normoxemia during the first 24 h. Immediate postmortem, bi-hemispheric (i.e., blood-injected and contra-lateral) prefrontal cortex specimens from the base of the sulci underwent immunohistochemistry (% positive tissue staining) analysis of oxidative/nitrosative stress, blood-brain barrier integrity and fluid homeostasis. None of these tissue markers explained any differences in hyperoxemia-related neurological function. Likewise, hyperoxemia exerted no deleterious effects.

COMBAT-C: COntrol of Major Bleeding by Application of Tourniquets over Clothing.

INTRODUCTION: External bleeding is the leading cause of preventable trauma-related death. In certain circumstances, tourniquet application over clothing may be necessary. Therefore, the aim of this study was to assess the effectiveness of tourniquets over different clothing setups. METHODS: Three windlass tourniquets (CAT, SAMXT, SOFTT-W) were applied over nine different clothing setups and without clothing on the Hapmed™ Tourniquet Trainer. We compared each tourniquet in each clothing setup to the tourniquet trainer that was not dressed, and we compared the three tourniquets within each clothing setup concerning blood loss, applied pressure and application time. Regression analysis of the effect of thickness, mean weight, mean deformation, application time, and applied pressure on blood loss was performed. RESULTS: Although blood loss was significantly greater in the CAT and SAMXT tourniquets when they were applied over leather motorcycle trousers, the overall findings showed that the clothing setups significantly reduced or did not affect blood loss. The mean blood loss was the lowest with CAT and the highest with SOFTT-W. The measured mean pressures were lower than 180 mmHg in four out of nine clothing setups with SOFTT-W, but CAT and SAMXT always exceeded this threshold. CAT had the fastest application time. Blood loss was significantly influenced by applied pressure and application time but was influenced to a far lesser degree by clothing parameters. CONCLUSION: The effects of the clothing setups were of little clinical relevance, except for leather motorcycle trousers. The effects of rugged protective equipment, e.g., hazard suits, are conceivable and need to be tested for specific garments with the tourniquet intended for use. No clothing parameter for predicting tourniquet effectiveness could be identified.

[Ultrasound diagnostics in prehospital emergency care-do we need a standardized educational approach?] / Ultraschalldiagnostik in der prähospitalen Notfallmedizin ­ brauchen wir eine standardisierte Ausbildung?

BACKGROUND: Limited diagnostic capabilities represent an ongoing obstacle in out-of-hospital emergency settings. Prehospital deployment of ultrasound might reduce this particular diagnostic gap. So far, little is known about the availability and usage of ultrasound in emergency medical services (EMS) or about the level of education of EMS physicians regarding prehospital ultrasound (point-of-care ultrasound, POCUS). METHODS: A nationwide survey was conducted among emergency physicians in Germany focusing on POCUS education and experience. RESULTS: Between 02/2022 and 05/2022, 1079 responses were registered, of which 853 complete responses were analyzed. Of the emergency physicians, 71.9% consider POCUS beneficial for out-of-hospital diagnostics and 43.8% had participated in a certified POCUS training prior to the survey. The self-evaluation of POCUS skills among emergency physicians depended significantly on their participation in a certified training (p < 0.001) and frequent ultrasound routine (p < 0.001). CONCLUSION: The majority of participating emergency physicians in Germany consider POCUS to improve out-of-hospital diagnostic capabilities. Participation in a certified POCUS training and frequent use of ultrasound facilitated higher self-confidence in POCUS skills.

An exploratory study investigating the effect of targeted hyperoxemia in a randomized controlled trial in a long-term resuscitated model of combined acute subdural hematoma and hemorrhagic shock in cardiovascular healthy pigs.

Severe physical injuries and associated traumatic brain injury and/or hemorrhagic shock (HS) remain leading causes of death worldwide, aggravated by accompanying extensive inflammation. Retrospective clinical data indicated an association between mild hyperoxemia and improved survival and outcome. However, corresponding prospective clinical data, including long-term resuscutation, are scarce. Therefore, the present study explored the effect of mild hyperoxemia for 24 hours in a prospective randomized controlled trial in a long-term resuscitated model of combined acute subdural hematoma (ASDH) and HS. ASDH was induced by injecting 0.1 ml × kg-1 autologous blood into the subdural space and HS was triggered by passive removal of blood. After 2 hours, the animals received full resuscitation, including retransfusion of the shed blood and vasopressor support. During the first 24 hours, the animals underwent targeted hyperoxemia (PaO2 = 200 - 250 mmHg) or normoxemia (PaO2 = 80 - 120 mmHg) with a total observation period of 55 hours after the initiation of ASDH and HS. Survival, cardiocirculatory stability, and demand for vasopressor support were comparable between both groups. Likewise, humoral markers of brain injury and systemic inflammation were similar. Multimodal brain monitoring, including microdialysis and partial pressure of O2 in brain tissue, did not show significant differences either, despite a significantly better outcome regarding the modified Glasgow Coma Scale 24 hours after shock that favors hyperoxemia. In summary, the present study reports no deleterious and few beneficial effects of mild targeted hyperoxemia in a clinically relevant model of ASDH and HS with long-term resuscitation in otherwise healthy pigs. Further beneficial effects on neurological function were probably missed due to the high mortality in both experimental groups. The present study remains exploratory due to the unavailability of an a priori power calculation resulting from the lack of necessary data.

The effect of sodium thiosulfate on immune cell metabolism during porcine hemorrhage and resuscitation.

Introduction: Sodium thiosulfate (Na2S2O3), an H2S releasing agent, was shown to be organ-protective in experimental hemorrhage. Systemic inflammation activates immune cells, which in turn show cell type-specific metabolic plasticity with modifications of mitochondrial respiratory activity. Since H2S can dose-dependently stimulate or inhibit mitochondrial respiration, we investigated the effect of Na2S2O3 on immune cell metabolism in a blinded, randomized, controlled, long-term, porcine model of hemorrhage and resuscitation. For this purpose, we developed a Bayesian sampling-based model for 13C isotope metabolic flux analysis (MFA) utilizing 1,2-13C2-labeled glucose, 13C6-labeled glucose, and 13C5-labeled glutamine tracers. Methods: After 3 h of hemorrhage, anesthetized and surgically instrumented swine underwent resuscitation up to a maximum of 68 h. At 2 h of shock, animals randomly received vehicle or Na2S2O3 (25 mg/kg/h for 2 h, thereafter 100 mg/kg/h until 24 h after shock). At three time points (prior to shock, 24 h post shock and 64 h post shock) peripheral blood mononuclear cells (PBMCs) and granulocytes were isolated from whole blood, and cells were investigated regarding mitochondrial oxygen consumption (high resolution respirometry), reactive oxygen species production (electron spin resonance) and fluxes within the metabolic network (stable isotope-based MFA). Results: PBMCs showed significantly higher mitochondrial O2 uptake and lower O 2 • - production in comparison to granulocytes. We found that in response to Na2S2O3 administration, PBMCs but not granulocytes had an increased mitochondrial oxygen consumption combined with a transient reduction of the citrate synthase flux and an increase of acetyl-CoA channeled into other compartments, e.g., for lipid biogenesis. Conclusion: In a porcine model of hemorrhage and resuscitation, Na2S2O3 administration led to increased mitochondrial oxygen consumption combined with stimulation of lipid biogenesis in PBMCs. In contrast, granulocytes remained unaffected. Granulocytes, on the other hand, remained unaffected. O 2 • - concentration in whole blood remained constant during shock and resuscitation, indicating a sufficient anti-oxidative capacity. Overall, our MFA model seems to be is a promising approach for investigating immunometabolism; especially when combined with complementary methods.

The effect of targeted hyperoxemia in a randomized controlled trial employing a long-term resuscitated, model of combined acute subdural hematoma and hemorrhagic shock in swine with coronary artery disease: An exploratory, hypothesis-generating study.

Controversial evidence is available regarding suitable targets for the arterial O2 tension (PaO2) after traumatic brain injury and/or hemorrhagic shock (HS). We previously demonstrated that hyperoxia during resuscitation from hemorrhagic shock attenuated cardiac injury and renal dysfunction in swine with coronary artery disease. Therefore, this study investigated the impact of targeted hyperoxemia in a long-term, resuscitated model of combined acute subdural hematoma (ASDH)-induced brain injury and HS. The prospective randomized, controlled, resuscitated animal investigation consisted of 15 adult pigs. Combined ASDH plus HS was induced by injection of 0.1 ml/kg autologous blood into the subdural space followed by controlled passive removal of blood. Two hours later, resuscitation was initiated comprising re-transfusion of shed blood, fluids, continuous i.v. noradrenaline, and either hyperoxemia (target PaO2 200 - 250 mmHg) or normoxemia (target PaO2 80 - 120 mmHg) during the first 24 h of the total of 54 h of intensive care. Systemic hemodynamics, intracranial and cerebral perfusion pressures, parameters of brain microdialysis and blood biomarkers of brain injury did not significantly differ between the two groups. According to the experimental protocol, PaO2 was significantly higher in the hyperoxemia group at the end of the intervention period, i.e., at 24 h of resuscitation, which coincided with a higher brain tissue PO2. The latter persisted until the end of observation period. While neurological function as assessed using the veterinary Modified Glasgow Coma Score progressively deteriorated in the control group, it remained unaffected in the hyperoxemia animals, however, without significant intergroup difference. Survival times did not significantly differ in the hyperoxemia and control groups either. Despite being associated with higher brain tissue PO2 levels, which were sustained beyond the intervention period, targeted hyperoxemia exerted neither significantly beneficial nor deleterious effects after combined ASDH and HS in swine with pre-existing coronary artery disease. The unavailability of a power calculation and, thus, the limited number of animals included, are the limitations of the study.

Mechanical chest compression devices under special circumstances.

AIM: According to the current resuscitation guidelines, the use of mechanical chest compression devices could be considered under special circumstances like transport with ongoing resuscitation or long-term resuscitation. The aim of this study was to investigate whether survival is improved using mechanical devices under such circumstances. METHODS: Out-of-hospital cardiac arrests from all high-quality data centres of the German Resuscitation Registry from 2007 to 2020 were investigated. The use of mechanical devices was compared separately for transport with ongoing resuscitation, prolonged resuscitation (>45 min), and resuscitation with fibrinolytic agents applied. Baseline characteristics, 30-day survival/discharged alive, and neurological function at discharge were analysed descriptively; and 30-day survival/discharged alive was additionally analysed using multivariate logistic regression. RESULTS: Overall, patients who were treated with a mechanical device tended to be younger and were significantly more likely to have a witnessed cardiac arrest and a shockable initial rhythm. During the study period, 4,851 patients were transported to hospital with ongoing resuscitation (devices used in 44.2%). The 30-day survival was equal (odds ratio, OR: 1.13, 95%-CI: 0.79-1.60). In 3,920 cases, a resuscitation duration > 45 min was documented (9.5% with device). When a device was used, 30-day survival was significantly increased (OR 2.33, 95%-CI: 1.30-4.15). Fibrinolytic agents were used in 2,106 patients (22.2% with device). Here, 30-day survival was significantly worse with a device (OR: 0.52, 95%-CI: 0.30-0.91). CONCLUSION: Mechanical devices are not associated with better survival when used during transport, but rescuer safety could still be an important argument for their use. Devices are associated with better survival in prolonged resuscitation, but worse survival when a fibrinolytic was used.

[Cardiopulmonary resuscitation of pregnant patients in the rescue service]. / Kardiopulmonale Reanimation der schwangeren Patientin im Rettungsdienst: Standardisierter Ansatz für das notfallmedizinische Management.

Cardiopulmonary resuscitation of a pregnant patient is a rarity in prehospital emergency medicine and an extraordinary challenge for the emergency team. Besides modifications to emergency medical procedures due to physiological changes during pregnancy, specific reversible causes must be considered and psychosocial difficulties must be managed. This article aims to present a standard operating procedure for this special situation. In these circumstances the basics of crew resource management (CRM) are of special interest for the emergency team and are therefore mentioned in this article.

H2S in acute lung injury: a therapeutic dead end(?).

This review addresses the plausibility of hydrogen sulfide (H2S) therapy for acute lung injury (ALI) and circulatory shock, by contrasting the promising preclinical results to the present clinical reality. The review discusses how the narrow therapeutic window and width, and potentially toxic effects, the route, dosing, and timing of administration all have to be balanced out very carefully. The development of standardized methods to determine in vitro and in vivo H2S concentrations, and the pharmacokinetics and pharmacodynamics of H2S-releasing compounds is a necessity to facilitate the safety of H2S-based therapies. We suggest the potential of exploiting already clinically approved compounds, which are known or unknown H2S donors, as a surrogate strategy.

Survival Following Lay Resuscitation.

BACKGROUND: Resuscitation by laypersons is important in bridging the time between the occurrence of an out-of-hospital cardiac arrest (OHCA) and the arrival of emergency rescue service personnel. Depending on the reason for the cardiac arrest, however, the effectiveness of chest compressions is uncertain. The aim of this study was to explore the impact of lay resuscitation on survival following OHCA of different causes. METHODS: The data set for analysis comprised all cases of cardiac arrest before the arrival of emergency rescue service personnel that were fully documented in the German Resuscitation Registry in the period 2007-2019. The following endpoints related to resuscitation by bystanders were evaluated-separately for each cause-descriptively and by means of multivariate logistic regression analysis: return of spontaneous circulation (ROSC), 30 days' survival/discharged alive from the hospital, and good neurological function at discharge. RESULTS: Altogether, 40 604 cases of cardiac arrest were included. Resuscitation by laypersons was carried out in 35.1% of these cases. The rate of ROSC was statistically significantly higher after lay resuscitation for OHCA caused by cardiac events, drowning, intoxication, or central nervous system disorders (overall 48.1% versus 41.0%). For all causes-with the exception of trauma/bleeding to death and sepsis- the endpoint 30 days' survival/discharged alive was better with lay resuscitation (overall 17.0% versus 9.5%). In multivariate regression analysis, lay resuscitation was associated with improvement of the endpoint 30 days' survival/discharged alive only for OHCA caused by cardiac events (odds ratio [OR] 1.16) or intoxication (OR 1.81). For all other causes-except hypoxia-lay resuscitation tended to yield better results. Neurological function at discharge was also significantly better (overall 11.5% versus 6.1%) after lay resuscitation for OHCA of all causes except trauma/ bleeding to death, hypoxia, and sepsis. CONCLUSION: Resuscitation by laypersons is associated with an improved result regarding the endpoint 30 days' survival/discharged alive in cases of OHCA caused by cardiac events and intoxication. These two groups account for 81% of the resuscitation patients in the study. Because there was also a tendency towards higher survival rates following OHCA of other causes (except hypoxia), laypersons should continue to be encouraged to attempt resuscitation in all cases of OHCA, whatever the cause.

Outcome after pre-hospital cardiac arrest in accordance with underlying cause.

AIM: In terms of treatment options, the underlying cause of out-of-hospital cardiac arrest (OHCA) has an impact on survival. This study aimed to examine the frequencies of different causes of OHCA and their outcomes using data from a national resuscitation registry. METHODS: All pre-hospital cardiopulmonary resuscitations (CPR) documented in the German Resuscitation Registry between 2007 and 2017 were retrospectively investigated with regard to cause of cardiac arrest, return of spontaneous circulation (ROSC), and hospital discharge rate with good neurological outcome. To avoid selection bias, only rescue services with a return rate in the form 'further clinical treatment' of >30% were included, this resulted in a total return rate of 84% of the included data. RESULTS: In total, 33,772 patients were included. The most common causes of OHCA were cardiac events (62.2%), hypoxia (11.1%) and trauma (3.2%), in 17.2% no or unknown cause were documented. Overall, 44.8% of patients achieved ROSC, 13.1% of patients were discharged alive from hospital and 68.3% of these were in good neurological condition (9.0% of all patients). ROSC rates differed between 8.9% (sudden infant death syndrome) and 64.4% (intracranial bleeding), while discharge rates with good neurological outcome ranged between 0.9% (sepsis) and 14.0% (intoxication). CONCLUSION: The most common causes of OHCA are cardiac events and hypoxia. Depending on the underlying cause, outcome after pre-hospital CPR varies widely with a survival rate with good neurological outcome ranging from 0.9 to 14%.

Hyperoxia or Therapeutic Hypothermia During Resuscitation from Non-Lethal Hemorrhagic Shock in Swine.

We previously demonstrated beneficial effects of 22 h of hyperoxia following near-lethal porcine hemorrhagic shock, whereas therapeutic hypothermia was detrimental. Therefore, we investigated whether shorter exposure to hyperoxia (12 h) would still improve organ function, and whether 12 h of hypothermia with subsequent rewarming could avoid deleterious effects after less severe hemorrhagic shock.Twenty-seven anesthetized and surgically instrumented pigs underwent 3 h of hemorrhagic shock by removal of 30% of the blood volume and titration of the mean arterial blood pressure (MAP) to 40 mm Hg. Post-shock, pigs were randomly assigned to control, hyperoxia (FIO2 100% for 12 h) or hypothermia group (34°C core temperature for 12 h with subsequent rewarming). Before, at the end of shock, after 12 and 23 h of resuscitation, data sets comprising hemodynamics, blood gases, and parameters of inflammation and organ function were acquired. Postmortem, kidney samples were collected for immunohistochemistry and western blotting.Hyperoxia exerted neither beneficial nor detrimental effects. In contrast, mortality in the hypothermia group was significantly higher compared with controls (67% vs. 11%). Hypothermia impaired circulation (MAP 64 (57;89) mm Hg vs. 104 (98; 114) mm Hg) resulting in metabolic acidosis (lactate 11.0 (6.6;13.6) mmol L vs. 1.0 (0.8;1.5) mmol L) and reduced creatinine clearance (26 (9;61) mL min vs. 77 (52;80) mL min) compared to the control group after 12 h of resuscitation. Impaired kidney function coincided with increased renal 3-nitrotyrosine formation and extravascular albumin accumulation.In conclusion, hyperoxia proved to be safe during resuscitation from hemorrhagic shock. The lacking organ-protective effects of hyperoxia compared to resuscitation from near-lethal hemorrhage suggest a dependence of the effectiveness of hyperoxia from shock severity. In line with our previous report, therapeutic hypothermia (and rewarming) was confirmed to be detrimental most likely due to vascular barrier dysfunction.

Effects of Hyperoxia and Mild Therapeutic Hypothermia During Resuscitation From Porcine Hemorrhagic Shock.

OBJECTIVE: Hemorrhagic shock-induced tissue hypoxia induces hyperinflammation, ultimately causing multiple organ failure. Hyperoxia and hypothermia can attenuate tissue hypoxia due to increased oxygen supply and decreased demand, respectively. Therefore, we tested the hypothesis whether mild therapeutic hypothermia and hyperoxia would attenuate postshock hyperinflammation and thereby organ dysfunction. DESIGN: Prospective, controlled, randomized study. SETTING: University animal research laboratory. SUBJECTS: Thirty-six Bretoncelles-Meishan-Willebrand pigs of either gender. INTERVENTIONS: After 4 hours of hemorrhagic shock (removal of 30% of the blood volume, subsequent titration of mean arterial pressure at 35 mm Hg), anesthetized and instrumented pigs were randomly assigned to "control" (standard resuscitation: retransfusion of shed blood, fluid resuscitation, norepinephrine titrated to maintain mean arterial pressure at preshock values, mechanical ventilation titrated to maintain arterial oxygen saturation > 90%), "hyperoxia" (standard resuscitation, but FIO2, 1.0), "hypothermia" (standard resuscitation, but core temperature 34°C), or "combi" (hyperoxia plus hypothermia) (n = 9 each). MEASUREMENTS AND MAIN RESULTS: Before, immediately at the end of and 12 and 22 hours after hemorrhagic shock, we measured hemodynamics, blood gases, acid-base status, metabolism, organ function, cytokine production, and coagulation. Postmortem kidney specimen were taken for histological evaluation, immunohistochemistry (nitrotyrosine, cystathionine γ-lyase, activated caspase-3, and extravascular albumin), and immunoblotting (nuclear factor-κB, hypoxia-inducible factor-1α, heme oxygenase-1, inducible nitric oxide synthase, B-cell lymphoma-extra large, and protein expression of the endogenous nuclear factor-κB inhibitor). Although hyperoxia alone attenuated the postshock hyperinflammation and thereby tended to improve visceral organ function, hypothermia and combi treatment had no beneficial effect. CONCLUSIONS: During resuscitation from near-lethal hemorrhagic shock, hyperoxia attenuated hyperinflammation, and thereby showed a favorable trend toward improved organ function. The lacking efficacy of hypothermia was most likely due to more pronounced barrier dysfunction with vascular leakage-induced circulatory failure.

Mechanical chest compression: an alternative in helicopter emergency medical services?

Mechanical chest compression devices are mentioned in the current guidelines of the European Resuscitation Council (ERC) as an alternative in long-lasting cardiopulmonary resuscitations (CPR) or during transport with ongoing CPR. We compared manual chest compression with mechanical devices in a rescue-helicopter-based scenario using a resuscitation manikin. Manual chest compression was compared with the mechanical devices LUCAS™ 2, AutoPulse™ and animax mono (10 series each) using the resuscitation manikin AmbuMan MegaCode Wireless, which was intubated endotracheally and controlled ventilated during the entire scenario. The scenario comprised the installation of each device, transport and loading phases, as well as a 10-min phase inside the helicopter (type BK 117). We investigated practicability as well as measured compression quality. All mechanical devices could be used readily in a BK 117 helicopter. The LUCAS 2 group was the only one that fulfilled all recommendations of the ERC (frequency 102 ± 0.1 min(-1), compression depth 54 ± 3 mm, hands-off time 2.5 ± 1.6 %). Performing adequate manual chest compression was barely possible (fraction of correct compressions 21 ± 15 %). In all four groups, the total hands-off time was <10 %. Performing manual chest compressions during rescue-helicopter transport is barely possible, and only of poor quality. If rescuers are experienced, mechanical chest compression devices could be good alternatives in this situation. We found that the LUCAS 2 system complied with all recommendations of ERC guidelines, and all three tested devices worked consistently during the entire scenario.

Cardio pump reloaded: in-hospital resuscitation during transport.

High-quality chest compressions are crucial during resuscitation if a positive outcome is to be achieved. Sometimes a patient must be transported within the hospital while chest compressions are being performed. We compared different chest compression devices [animax mono (AM), AutoPulse(®) (AP) and LUCAS2™ (L2)] with manual chest compression using a manikin during transport from a fifth floor ward to the cardiac catheterization laboratory in the basement. Chest compressions were interrupted for 10.7 s to set up the AM, 15.3 s for the L2 and 23.5 s for the AP. The use of a mechanical device reduced transport times from 144.5 s when manual compressions were underway, to 126.8, 111.1 and 98.5 s with the AM, L2 and AP, respectively (p < 0.05). Transfer to the laboratory gurney required little or no interruption in chest compressions with the L2 (0.8 s) and AP (no interruption), compared with 10.3 s with the AP and 3.3 s for manual compressions. Manual compression frequency was 124 min(-1), compared with 100.4 min(-1) for the AM, 99.9 min(-1) for the L2 and 79.7 min(-1) for the AP. Compression depth did not change during transport in any group. Mechanical compression devices are suitable for use during transport, but are not clearly superior to manual compressions. Devices maintain the same compression depth, but fell short of current guidelines, as did manual compressions. Some interruptions occurred while the devices were set up. Further, patient studies are necessary to determine the clinical utility of these devices.

Transport with ongoing resuscitation: a comparison between manual and mechanical compression.

AIM: In special circumstances it may be necessary to transport out-of-hospital cardiac arrest patients with ongoing resuscitation to the hospital. External mechanical chest compression devices could be an alternative for these resuscitations. The study compares manual chest compression with external mechanical devices and a semiautomatic device in transport conditions using a resuscitation manikin. METHODS: Manual chest compressions were compared with LUCAS 2, AutoPulse and animax mono devices using the Ambu Man Wireless MegaCode manikin (10 series each). The measurements were performed in a standard ambulance vehicle during transport on a predefined track of 5.0 km. RESULTS: Mean compression frequencies in the manual group (117 ± 18 min(-1)) and in the animax mono group (115 ± 10 min(-1)) were significantly higher than in the LUCAS 2 group (100 min(-1), p=0.02) and the AutoPulse group (80 min(-1), p<0.01). Both mechanical devices worked absolutely constantly. Only the animax mono group reached with 51.2 mm the recommended compression depth. The quality of manual compressions decreased considerably during braking or change manoeuvres while the mechanical devices continued to work constantly. CONCLUSIONS: During a patient transport with ongoing resuscitation, external mechanical compression devices may be a good alternative to manual compression because they increase the safety of the rescuer and patient. Yet, in this study only animax mono reached the guideline specifications regarding chest compressions' frequency and depth. Concerning constancy, the mechanical devices work reliably and more independently from motion influences. Further studies are necessary to evaluate the effectiveness of these devices in patient transport.

Socioeconomic status, status inconsistency and risk of ischaemic heart disease: a prospective study among members of a statutory health insurance company.

BACKGROUND: Inconsistency in social status and its impact on health have been a focus of research 30-40 years ago. Yet, there is little recent information on it's association with ischaemic heart disease (IHD) morbidity and IHD is still defined as one of the major health problems in socioeconomically developed societies. METHODS: A secondary analysis of prospective historical data from 68 805 male and female members of a statutory German health insurance company aged 25-65 years was conducted. Data included information on sociodemographic variables, social status indicators (education, occupational grade and income) and hospital admissions because of IHD. RESULTS: Findings from Cox regression analysis showed an increased risk for IHD in the group with the highest educational level, whereas the lowest occupational and income groups had the highest hazard ratio (HR). Further analysis revealed that after adjustment for income status inconsistency (defined by the combination of higher educational level with lower occupational status) accounts for increased risk of IHD (HR for men, 3.14 and for women, 3.63). An association of similar strength was observed regarding high education/low income in women (HR 3.53). The combination of low education with high income reduced the risk among men (HR 0.29). No respective findings were observed concerning occupational group and income. CONCLUSIONS: Status inconsistency is associated with the risk of IHD as well as single traditional indicators of socioeconomic position. Information on status inconsistency should be measured in addition to single indicators of socioeconomic status to achieve a more appropriate estimation of the risk of IHD.