Rhizosheath drought responsiveness is variety-specific and a key component of belowground plant adaptation.

Biophysicochemical rhizosheath properties play a vital role in plant drought adaptation. However, their integration into the framework of plant drought response is hampered by incomplete mechanistic understanding of their drought responsiveness and unknown linkage to intraspecific plant-soil drought reactions. Thirty-eight Zea mays varieties were grown under well-watered and drought conditions to assess the drought responsiveness of rhizosheath properties, such as soil aggregation, rhizosheath mass, net-rhizodeposition, and soil organic carbon distribution. Additionally, explanatory traits, including functional plant trait adaptations and changes in soil enzyme activities, were measured. Drought restricted soil structure formation in the rhizosheath and shifted plant-carbon from litter-derived organic matter in macroaggregates to microbially processed compounds in microaggregates. Variety-specific functional trait modifications determined variations in rhizosheath drought responsiveness. Drought responses of the plant-soil system ranged among varieties from maintaining plant-microbial interactions in the rhizosheath through accumulation of rhizodeposits, to preserving rhizosheath soil structure while increasing soil exploration through enhanced root elongation. Drought-induced alterations at the root-soil interface may hold crucial implications for ecosystem resilience in a changing climate. Our findings highlight that rhizosheath soil properties are an intrinsic component of plant drought response, emphasizing the need for a holistic concept of plant-soil systems in future research on plant drought adaptation.

Unraveling root and rhizosphere traits in temperate maize landraces and modern cultivars: Implications for soil resource acquisition and drought adaptation.

A holistic understanding of plant strategies to acquire soil resources is pivotal in achieving sustainable food security. However, we lack knowledge about variety-specific root and rhizosphere traits for resource acquisition, their plasticity and adaptation to drought. We conducted a greenhouse experiment to phenotype root and rhizosphere traits (mean root diameter [Root D], specific root length [SRL], root tissue density, root nitrogen content, specific rhizosheath mass [SRM], arbuscular mycorrhizal fungi [AMF] colonization) of 16 landraces and 22 modern cultivars of temperate maize (Zea mays L.). Our results demonstrate that landraces and modern cultivars diverge in their root and rhizosphere traits. Although landraces follow a 'do-it-yourself' strategy with high SRLs, modern cultivars exhibit an 'outsourcing' strategy with increased mean Root Ds and a tendency towards increased root colonization by AMF. We further identified that SRM indicates an 'outsourcing' strategy. Additionally, landraces were more drought-responsive compared to modern cultivars based on multitrait response indices. We suggest that breeding leads to distinct resource acquisition strategies between temperate maize varieties. Future breeding efforts should increasingly target root and rhizosphere economics, with SRM serving as a valuable proxy for identifying varieties employing an outsourcing resource acquisition strategy.

Temperature Control After In-Hospital Cardiac Arrest: A Randomized Clinical Trial.

BACKGROUND: This study was conducted to determine the effect of hypothermic temperature control after in-hospital cardiac arrest (IHCA) on mortality and functional outcome as compared with normothermia. METHODS: An investigator initiated, open-label, blinded-outcome-assessor, multicenter, randomized controlled trial comparing hypothermic temperature control (32-34°C) for 24 h with normothermia after IHCA in 11 hospitals in Germany. The primary endpoint was all-cause mortality after 180 days. Secondary end points included in-hospital mortality and favorable functional outcome using the Cerebral Performance Category scale after 180 days. A Cerebral Performance Category score of 1 or 2 was defined as a favorable functional outcome. RESULTS: A total of 1055 patients were screened for eligibility and 249 patients were randomized: 126 were assigned to hypothermic temperature control and 123 to normothermia. The mean age of the cohort was 72.6±10.4 years, 64% (152 of 236) were male, 73% (166 of 227) of cardiac arrests were witnessed, 25% (57 of 231) had an initial shockable rhythm, and time to return of spontaneous circulation was 16.4±10.5 minutes. Target temperature was reached within 4.2±2.8 hours after randomization in the hypothermic group and temperature was controlled for 48 hours at 37.0°±0.9°C in the normothermia group. Mortality by day 180 was 72.5% (87 of 120) in hypothermic temperature control arm, compared with 71.2% (84 of 118) in the normothermia group (relative risk, 1.03 [95% CI, 0.79-1.40]; P=0.822). In-hospital mortality was 62.5% (75 of 120) in the hypothermic temperature control as compared with 57.6% (68 of 118) in the normothermia group (relative risk, 1.11 [95% CI, 0.86-1.46, P=0.443). Favorable functional outcome (Cerebral Performance Category 1 or 2) by day 180 was 22.5% (27 of 120) in the hypothermic temperature control, compared with 23.7% (28 of 118) in the normothermia group (relative risk, 1.04 [95% CI, 0.78-1.44]; P=0.822). The study was prematurely terminated because of futility. CONCLUSIONS: Hypothermic temperature control as compared with normothermia did not improve survival nor functional outcome at day 180 in patients presenting with coma after IHCA. The HACA in-hospital trial (Hypothermia After Cardiac Arrest in-hospital) was underpowered and may have failed to detect clinically important differences between hypothermic temperature control and normothermia. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique Identifier: NCT00457431.

Above and belowground traits impacting transpiration decline during soil drying in 48 maize (Zea mays) genotypes.

BACKGROUND AND AIMS: Stomatal regulation allows plants to promptly respond to water stress. However, our understanding of the impact of above and belowground hydraulic traits on stomatal regulation remains incomplete. The objective of this study was to investigate how key plant hydraulic traits impact transpiration of maize during soil drying. We hypothesize that the stomatal response to soil drying is related to a loss in soil hydraulic conductivity at the root-soil interface, which in turn depends on plant hydraulic traits. METHODS: We investigate the response of 48 contrasting maize (Zea mays) genotypes to soil drying, utilizing a novel phenotyping facility. In this context, we measure the relationship between leaf water potential, soil water potential, soil water content and transpiration, as well as root, rhizosphere and aboveground plant traits. KEY RESULTS: Genotypes differed in their responsiveness to soil drying. The critical soil water potential at which plants started decreasing transpiration was related to a combination of above and belowground traits: genotypes with a higher maximum transpiration and plant hydraulic conductance as well as a smaller root and rhizosphere system closed stomata at less negative soil water potentials. CONCLUSIONS: Our results demonstrate the importance of belowground hydraulics for stomatal regulation and hence drought responsiveness during soil drying. Furthermore, this finding supports the hypothesis that stomata start to close when soil hydraulic conductivity drops at the root-soil interface.

Temperature control in adults after cardiac arrest: a survey of current clinical practice in Germany.

BACKGROUND: Temperature control is recommended after out of hospital cardiac arrest (OHCA) by international guidelines. This survey aimed to investigate current clinical practice and areas of uncertainty. METHODS: Online survey targeting members of three medical emergency and critical care societies in Germany (April 21-June 6, 2022) assessing post-cardiac arrest temperature control management. RESULTS: Of 341 completed questionnaires 28% (n = 97) used temperature control with normothermic target and 72% (n = 244) temperature control with hypothermic target. The definition of fever regarding patients with cardiac arrest ranged from ≥ 37.7 to 39.0 °C. Temperature control was mainly started in the ICU (80%, n = 273) and most commonly core cooling (74%, n = 254) and surface cooling (39%, n = 134) with feedback were used. Temperature control was maintained for 24 h in 18% (n = 61), 48 h in 28% (n = 94), 72 h in 42% (n = 143) and longer than 72 h in 13% (n = 43). 7% (n = 24) were using different protocols for OHCA with initial shockable and non-shockable rhythm. Additional 14% (n = 48) were using different temperature control protocols after in-hospital cardiac arrest (IHCA) compared with OHCA. Overall, 37% (n = 127) changed practice after the publication of the ERC-2021 guidelines and 33% (n = 114) after the recent publication of the revised ERC-ESICM guideline on temperature control. CONCLUSIONS: One-third of the respondents changed clinical practice since recent guideline update. However, a majority of physicians further trusts in temperature control with a hypothermic target. Of interest, 14% used different temperature control strategies after IHCA compared with OHCA and 7% for shockable and non-shockable initial rhythm. A more individualized approach in post resuscitation care may be warranted.

[Practical use of digital health applications (DiGA) in internal medicine]. / Praktische Anwendung digitaler Gesundheitsanwendungen (DiGA) in der Inneren Medizin.

Since 2020 physicians can prescribe digital health applications (DiGA), also colloquially known as apps on prescription, which are reimbursed by the statutory health insurance when they are approved by the Federal Institute for Drugs and Medical Devices (BfArM) and are included in the DiGA Ordinance. Currently, there is one approved DiGA (indication obesity) for internal medicine. There are many questions on the practical use of the DiGA, ranging from the prescription, the effectiveness, the complexities and reimbursement as well as the liability risks. The DiGA are innovative new means, which maybe support internal medicine physicians in the diagnostics and treatment in the future. The benefits in this field of indications are limited by unclarified issues, especially on the prescription practice and the currently low number of DiGA available in internal medicine.

Explicit Diagnostic Criteria for Transient Ischemic Attacks Used in the Emergency Department Are Highly Sensitive and Specific.

BACKGROUND: Making a correct diagnosis of a transient ischemic attack (TIA) is prone to errors because numerous TIA mimics exist and there is a shortage of evidence-based diagnostic criteria for TIAs. In this study, we applied for the first time the recently proposed explicit diagnostic criteria for transient ischemic attacks (EDCT) to a group of patients presenting to the emergency department of a large German tertiary care hospital with a suspected TIA. The aim was to determine the sensitivity and specificity of the EDCT in its clinical application. METHODS: A total of 128 patients consecutively presenting to the emergency department of the University Hospital of Lübeck, Germany, under the suspicion of a TIA were prospectively interviewed about their clinical symptoms at the time of presentation. The diagnosis resulting from applying the EDCT was compared to the diagnosis made independently by the senior physicians performing the usual diagnostic work-up ("gold standard"), allowing calculation of sensitivity and specificity of the EDCT. RESULTS: EDCT achieved a sensitivity of 96% and a specificity of 88%. When adding the additional criterion F ("the symptoms may not be better explained by another medical or mental disorder"), specificity significantly increased to 98%. CONCLUSIONS: The data show that the EDCT in its modified version as proposed by us are a highly useful tool for clinicians. They display a high sensitivity and specificity to accurately diagnose TIAs in patients referred to the emergency department with a suspected TIA.

ICHD-3 is significantly more specific than ICHD-3 beta for diagnosis of migraine with aura and with typical aura.

BACKGROUND: In the emergency room, distinguishing between a migraine with aura and a transient ischemic attack (TIA) is often not straightforward and mistakes can be harmful to both the patient and to society. To account for this difficulty, the third edition of the International Classification of Headache disorders (ICHD-3) changed the diagnostic criteria of migraine with aura. METHODS: One hundred twenty-eight patients referred to the emergency room at the University Hospital of Lübeck, Germany with a suspected TIA were prospectively interviewed about their symptoms leading to admission shortly after initial presentation. The diagnosis that resulted from applying the ICHD-3 and ICHD-3 beta diagnostic criteria was compared to the diagnosis made independently by the treating physicians performing the usual diagnostic work-up. RESULTS: The new ICHD-3 diagnostic criteria for migraine with aura and migraine with typical aura display an excellent specificity (96 and 98% respectively), and are significantly more specific than the previous ICHD-3 beta classification system when it comes to diagnosing a first single attack (probable migraine with aura and probable migraine with typical aura). CONCLUSIONS: The ICHD-3 is a highly useful tool for the clinical neurologist in order to distinguish between a migraine with aura and a TIA, already at the first point of patient contact, such as in the emergency department or a TIA clinic.

Age-associated outcomes after survived out-of-hospital cardiac arrest and subsequent target temperature management.

BACKGROUND: The registry of the German Society of Intensive Care and Emergency Medicine was founded to analyze outcome of modern post-resuscitation care. METHODS: A total of 902 patients were analyzed in this retrospective, multicenter, and population-based observational trial on individuals suffering from out-of-hospital cardiac arrest. All patients had return of spontaneous circulation (ROSC) and received TTM after admitted to an intensive care unit. Outcome was focused on age and analyzed by creating 4 subgroups (<65, 65-74, 75-84, ≥85 years). Twenty-eight day and 180-day survival and a favorable neurological outcome according to the Cerebral Performance Category scale were evaluated as clinical endpoints. RESULTS: At 28-day and 180-day follow-up, 44.8% and 53.4% of all patients had died, respectively. The evaluation of survival rate by age category revealed a higher mortality, but not an unfavorable neurological prognosis with increasing age. In multiple stepwise regressions, age, time to ROSC, bystander resuscitation, and cardiac cause of cardiac arrest were associated with increased chance of 180-day survival and, in addition, bystander resuscitation, time of hypoxia, and a defibrillation performed by emergency medical service were associated with a favorable neurological outcome at 180-day follow-up. CONCLUSION: Increasing age was associated with a higher mortality, but not with an unfavorable neurological outcome. The majority of survivors had a favorable neurologic outcome 6 months after cardiac arrest.

Farmland biodiversity and agricultural management on 237 farms in 13 European and two African regions.

Farmland is a major land cover type in Europe and Africa and provides habitat for numerous species. The severe decline in farmland biodiversity of the last decades has been attributed to changes in farming practices, and organic and low-input farming are assumed to mitigate detrimental effects of agricultural intensification on biodiversity. Since the farm enterprise is the primary unit of agricultural decision making, management-related effects at the field scale need to be assessed at the farm level. Therefore, in this study, data were collected on habitat characteristics, vascular plant, earthworm, spider, and bee communities and on the corresponding agricultural management in 237 farms in 13 European and two African regions. In 15 environmental and agricultural homogeneous regions, 6-20 farms with the same farm type (e.g., arable crops, grassland, or specific permanent crops) were selected. If available, an equal number of organic and non-organic farms were randomly selected. Alternatively, farms were sampled along a gradient of management intensity. For all selected farms, the entire farmed area was mapped, which resulted in total in the mapping of 11 338 units attributed to 194 standardized habitat types, provided together with additional descriptors. On each farm, one site per available habitat type was randomly selected for species diversity investigations. Species were sampled on 2115 sites and identified to the species level by expert taxonomists. Species lists and abundance estimates are provided for each site and sampling date (one date for plants and earthworms, three dates for spiders and bees). In addition, farmers provided information about their management practices in face-to-face interviews following a standardized questionnaire. Farm management indicators for each farm are available (e.g., nitrogen input, pesticide applications, or energy input). Analyses revealed a positive effect of unproductive areas and a negative effect of intensive management on biodiversity. Communities of the four taxonomic groups strongly differed in their response to habitat characteristics, agricultural management, and regional circumstances. The data has potential for further insights into interactions of farmland biodiversity and agricultural management at site, farm, and regional scale.

[Clinical acute and emergency medicine curriculum-focus on internal medicine : Recommendations for advanced training in internal medicine in the emergency department]. / Curriculum Klinische Akut- und Notfallmedizin ­ Schwerpunkt Innere Medizin : Empfehlung zu Weiterbildungsinhalten der Inneren Medizin in der Notaufnahme.

In Germany, physicians qualify for emergency medicine by combining a specialty medical training-e.g. internal medicine-with advanced training in emergency medicine according to the statutes of the State Chambers of Physicians largely based upon the Guideline Regulations on Specialty Training of the German Medical Association. Internal medicine and their associated subspecialities represent an important column of emergency medicine. For the internal medicine aspects of emergency medicine, this curriculum presents an overview of knowledge, skills (competence levels I-III) as well as behaviours and attitudes allowing for the best treatment of patients. These include general aspects (structure and process quality, primary diagnostics and therapy as well as indication for subsequent treatment; resuscitation room management; diagnostics and monitoring; general therapeutic measures; hygiene measures; and pharmacotherapy) and also specific aspects concerning angiology, endocrinology, diabetology and metabolism, gastroenterology, geriatric medicine, hematology and oncology, infectiology, cardiology, nephrology, palliative care, pneumology, rheumatology and toxicology. Publications focussing on contents of advanced training are quoted in order to support this concept. The curriculum has primarily been written for internists for their advanced emergency training, but it may generally show practising emergency physicians the broad spectrum of internal medicine diseases or comorbidities presented by patients attending the emergency department.

[Procedure after successful cardiopulmonary resuscitation-Cooling or no more cooling?] / Vorgehen nach erfolgreicher Reanimation ­ kühlen oder nicht mehr kühlen?

Approximately 84 out of 100,000 inhabitants in Europe suffer from an out of hospital cardiac arrest (OHCA) each year. The mortality after cardiac arrest (CA) is high and is particularly determined by the predominant cardiogenic shock condition and hypoxic ischemic encephalopathy. For almost two decades hypothermic temperature control was the only neuroprotective intervention recommended in guidelines for postresuscitation care; however, recently published studies failed to demonstrate any improvement in the neurological outcome with hypothermia in comparison to strict normothermia in postresuscitation treatment. According to the European Resuscitation Council (ERC) and European Society of Intensive Care Medicine (ESICM) guidelines published in 2022, unconscious adults after CA should be treated with temperature management and avoidance of fever; however, many questions remain open regarding the optimal target temperature, the cooling methods and the optimal duration. Despite these currently unanswered questions, a structured and high-quality postresuscitation care that includes a targeted temperature management should continue to be provided for all patients in the postresuscitation phase, independent of the selected target temperature. Furthermore, fever avoidance remains an important component of postresuscitation care.

[Hypothermic temperature control after successful resuscitation of out-of-hospital cardiac arrest in adults : Statement from the resuscitation and postresuscitation treatment working groups of the German Society of Medical Intensive Care and Emergency Medicine (DGIIN) and the German Interdisciplinary Association for Intensive Care and Emergency Medicine (DIVI), the German Society for Interdisciplinary Emergency and Acute Medicine (DGINA) and the Austrian Association of Emergency Medicine (AAEM)]. / Hypotherme Temperaturkontrolle nach erfolgreicher Wiederbelebung eines außerklinischen Herz-Kreislauf-Stillstands beim Erwachsenen : Statement der Arbeitsgruppen Reanimation und Post-Reanimationsbehandlung in der Deutschen Gesellschaft für Internistische Intensiv- und Notfallmedizin (DGIIN) und Deutschen Interdisziplinären Vereinigung für Intensiv- und Notfallmedizin (DIVI), der Deutschen Gesellschaft Interdisziplinäre Notfall- und Akutmedizin (DGINA) und der Österreichischen Gesellschaft für Notfallmedizin (AAEM).

In Germany per year approximately 60,000 and in Austria 5,000 adult patients suffer from out-of-hospital cardiac arrest. Only 10-15% of these patients survive without neurological damage. For decades hypothermic temperature control has been a central component of post-resuscitation treatment, but is controversial due to recently published studies.

[Monitoring of emergency cardiovascular patients in the emergency department : Consensus paper of the DGK, DGINA and DGIIN]. / Monitoring kardiovaskulärer Notfallpatienten in der Notaufnahme : Konsensuspapier der DGK, DGINA und DGIIN.

Patients with potential or proven cardiovascular diseases represent a relevant proportion of the total spectrum in the emergency department. Their monitoring for cardiovascular surveillance until the diagnostics and acute treatment are initiated, often poses an interdisciplinary and interprofessional challenge, because resources are limited, nevertheless a high level of patient safety has to be ensured and the correct procedure has a major prognostic significance. This consensus paper provides an overview of the practical implementation, the modalities of monitoring and the application in a selection of cardiovascular diagnoses. The article provides specific comments on the clinical presentations of acute coronary syndrome, acute heart failure, cardiogenic shock, hypertensive emergency events, syncope, acute pulmonary embolism and cardiac arrhythmia. The level of evidence is generally low as no randomized trials are available on this topic. The recommendations are intended to supplement or establish local standards and to assist all physicians, nursing personnel and the patients to be treated in making decisions about monitoring in the emergency department.

[Recommendations for Education in Sonography in Prehospital Emergency Medicine (pPOCUS): Consensus paper of DGINA, DGAI, BAND, BV-ÄLRD, DGU, DIVI and DGIIN]. / Empfehlungen zur Sonografieausbildung in der prähospitalen Notfallmedizin (pPOCUS): Konsensuspapier von DGINA, DGAI, BAND, BV-ÄLRD, DGU, DIVI und DGIIN.

Point-of-care sonography is a precondition in acute and emergency medicine for the diagnosis and initiation of therapy for critically ill and injured patients. While emergency sonography is a mandatory part of the training for clinical acute and emergency medicine, it is not everywhere required for prehospital emergency medicine. Although some medical societies in Germany have already established their own learning concepts for emergency ultrasound, a uniform national training concept for the use of emergency sonography in the out-of-hospital setting is still lacking. Experts of several professional medical societies have therefore joined forces and developed a structured training concept for emergency sonography in the prehospital setting. The consensus paper serves as quality assurance in prehospital emergency sonography.

[Recommendations for Education in Sonography in Prehospital Emergency Medicine (pPOCUS): Consensus paper of DGINA, DGAI, BAND, BV-ÄLRD, DGU, DIVI and DGIIN]. / Empfehlungen zur Sonografieausbildung in der prähospitalen Notfallmedizin (pPOCUS): Konsensuspapier von DGINA, DGAI, BAND, BV-ÄLRD, DGU, DIVI und DGIIN.

Point-of-care sonography is a precondition in acute and emergency medicine for the diagnosis and initiation of therapy for critically ill and injured patients. While emergency sonography is a mandatory part of the training for clinical acute and emergency medicine, it is not everywhere required for prehospital emergency medicine. Although some medical societies in Germany have already established their own learning concepts for emergency ultrasound, a uniform national training concept for the use of emergency sonography in the out-of-hospital setting is still lacking. Experts of several professional medical societies have therefore joined forces and developed a structured training concept for emergency sonography in the prehospital setting. The consensus paper serves as quality assurance in prehospital emergency sonography.

[Evidence of positive care effects by digital health apps-methodological challenges and approaches]. / Nachweis positiver Versorgungseffekte von digitalen Gesundheitsanwendungen ­ methodische Herausforderungen und Lösungsansätze.

Since 2020, digital health applications (DiGA) can be prescribed at the expense of the German statutory health insurance (SHI) system after undergoing an approval procedure by the Federal Institute for Drugs and Medical Devices (BfArM). DiGA can be approved provisionally for 1 year (with the option of extension) or permanently. The latter is dependent on scientific evidence of a positive effect on care, which can be a medical benefit or a patient-relevant structural and procedural improvement in care. However, it is apparent that the investigation of DiGA in scientific studies is challenging, as they are often complex interventions whose success also includes user and prescriber factors. In addition, health services research data underpinning the benefits of DiGA are lacking to date. In the current article, methodological considerations for DiGA research are presented, and a selection of internal medicine DiGAs is used to critically discuss current research practice.

Sex-specific differences and outcome in elderly patients after survived out-of-hospital cardiac arrest.

BACKGROUND: Little is known about sex differences in elderly patients after out-of-hospital cardiac arrest (OHCA) with return of spontaneous circulation (ROSC) and subsequent target temperature management (TTM). Therefore, this study was designed to evaluate sex-specific differences in survival and neurological outcome in elderly patients at 28-day and 180-day follow-up. METHODS: A total of 468 nontraumatic OHCA survivors with preclinical ROSC and an age of ≥ 65 years were included in this study. Sex-specific differences in survival and a favorable neurological outcome according to the cerebral performance category (CPC) score were evaluated as clinical endpoints. RESULTS: Of all participants included, 70.7% were men and 29.3% women. Women were significantly older (p = 0.011) and were more likely to have a nonshockable rhythm (p = 0.001) than men. Evaluation of survival rate and favorable neurological outcome by sex category showed no significant differences at 28-day and 180-day follow-up. In multiple stepwise logistic regression analysis, age (odds ratio 0.932 [95% confidence interval 0.891-0.951], p = 0.002) and time of hypoxia (0.899 [0.850-0.951], p < 0.001) proved to be independent predictors of survival only in male patients, whereas an initial shockable rhythm (4.325 [1.309-14.291], p = 0.016) was associated with 180-day survival in female patients. The majority of patients (93.7%) remained in the same CPC category when comparing 28-day and 180-day follow-up. CONCLUSION: Our results show no significant sex-specific differences in survival or favorable neurological outcome in elderly patients after having survived OHCA, but sex-specific predictors for 180-day survival. Moreover, the neurological assessment 28 days after the index event also seems to provide a valid indication for the further prognosis in elderly patients.

PrEdictive value of coMbined pre-test proBability and blOod gas anaLysis In pulmonary emboliSM-the EMBOLISM study.

In patients with suspected pulmonary embolism (PE), the number of unnecessary computed tomography pulmonary angiography (CTPA) scans remains high, especially in patients with low pre-test probability (PTP). So far, no study showed any additional benefit of capillary blood gas analysis (BGA) in diagnostic algorithms for PE. In this retrospective analysis of patients with suspected PE and subsequent CTPA, clinical data, D-dimer levels and BGA parameters (including standardized PaO2) were analyzed. Logistic regression analyses were performed to identify independent predictors for PE and reduce unnecessary CTPA examinations in patients with low PTP according to Wells score. Of 1538 patients, PE was diagnosed in 433 patients (28.2%). The original Wells score (odds ratio: 1.381 [95% CI 1.300-1.467], p < 0.001) and standardized PaO2 (odds ratio: 0.987 [95% CI 0.978-0.996], p = 0.005) were independent predictors for PE. After cohort adjustment for low PTP a D-dimer cut-off < 1.5 mg/L (278 patients (18.1%) with 18 PE (6.5%)) was identified in which a standardized PaO2 > 65 mmHg reduced the number of unnecessary CTPA by 31.9% with a 100% sensitivity. This approach was further validated in additional 53 patients with low PTP. In this validation group CTPA examinations were reduced by 32.7%. No patient with PE was missed. With our novel algorithm combining BGA testing with low PTP according to Wells score, we were able to increase the D-Dimer threshold to 1.5 mg/L and reduce CTPA examinations by approximately 32%.