Stress hyperglycaemia following trauma - a survival benefit or an outcome detriment?

PURPOSE OF REVIEW: Stress hyperglycaemia occur often in critically injured patients. To gain new consideration about it, this review compile current as well as known immunological and biochemical findings about causes and emergence. RECENT FINDINGS: Glucose is the preferred energy substrate for fending immune cells, reparative tissue and the cardiovascular system following trauma. To fulfil these energy needs, the liver is metabolically reprogrammed to rebuild glucose from lactate and glucogenic amino acids (hepatic insulin resistance) at the expenses of muscles mass and - to a less extent - fat tissue (proteolysis, lipolysis, peripheral insulin resistance). This inevitably leads to stress hyperglycaemia, which is evolutionary preserved and seems to be an essential and beneficial survival response. It is initiated by damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs), intensified by immune cells itself and mainly ruled by tumour necrosis factor (TNF)α and catecholamines with lactate and hypoxia inducible factor (HIF)-1α as intracellular signals and lactate as an energy shuttle. Important biochemical mechanisms involved in this response are the Warburg effect as an efficient metabolic shortcut and the extended Cori cycle. SUMMARY: Stress hyperglycaemia is beneficial in an acute life-threatening situation, but further research is necessary, to prevent trauma patients from the detrimental effects of persisting hyperglycaemia.

Conventional video recordings dependably quantify whole-body lifting strategy using the Stoop-Squat-Index: A methods comparison against motion capture and a reliability study.

Whole-body lifting strategies could be derived from conventional video recordings using the Stoop-Squat-Index, which quantifies the ratio between trunk forward lean and lower extremity joint flexion from 0 (full squat) to 100 (full stoop). The purpose of this study was to compare Stoop-Squat-Indices derived from conventional video recordings to those from a three-dimensional marker-based motion capture system and to evaluate interrater and intrarater reliability of the video-based approach. Thirty healthy participants lifted a 5-kg box under different conditions (freestyle, squat, stoop). Kinematic data were recorded using a Vicon motion capture system (serving as reference standard) and an iPad camera. Stoop-Squat-Indices over the entire lifting cycle were derived separately from both approaches. Agreement was assessed using mean differences (video minus motion capture) and limits of agreement. Reliability was investigated by calculating intraclass correlation coefficients (ICC) and minimal detectable changes (MDC) over the course of the lifting cycle. Systematic errors were identified with Statistical Parametric Mapping-based T-tests. Systematic errors between the video-based and the motion capture-based approach were observed among all conditions. Mean differences in Stoop-Squat-Indices over the lifting cycle ranged from -6.9 to 3.2 (freestyle), from -1.8 to 5.3 (squat) and from -2.8 to -1.1 (stoop). Limits of agreement were lower when the box was close to the floor, and higher towards upright standing. Reliability of the video-based approach was excellent for most of the lifting cycle, with ICC above 0.995 and MDC below 3.5. These findings support using a video-based assessment of Stoop-Squat-Indices to quantify whole-body lifting strategy in field.

Gender-specific homophily on Instagram and implications on information spread.

More and more social interactions happen online. On online social networks such as Instagram, millions of users share, like, and comment on photos and videos every day, interacting with other users world wide, at large scale and at a high rate. These networks do not only introduce new user experiences, but they also enable new insights into human behavior. Here, we use these new possibilities to study homophilic behavior-the tendency of individuals to bond with people similar to themselves. While homophilic behavior has been observed in many contexts, little is known about gender-specific differences and the extent of homophilic behavior of female and male users in online social networks. Based on a unique and extensive data set, covering over 800,000 (directed) Instagram interactions and a time span of three years, we shed light on differences between genders and uncover an intriguing asymmetry of homophily. In particular, we show that female users exhibit homophily to a larger extent than male users. The magnitude of this asymmetry depends on the type of interaction, as differences are more pronounced for 'comment'-interactions than for 'like'-interactions. Given these empirical observations, we further study the implications of such gender differences on the spread of information in social networks in a basic model. We find that on average, a piece of information that originates from a female group reaches significantly more female users than male users.

Predicted vs. measured paraspinal muscle activity in adolescent idiopathic scoliosis patients: EMG validation of optimization-based musculoskeletal simulations.

Musculoskeletal (MSK) models offer great potential for predicting the muscle forces required to inform more detailed simulations of vertebral endplate loading in adolescent idiopathic scoliosis (AIS). In this work, simulations based on static optimization were compared with in vivo measurements in two AIS patients to determine whether computational approaches alone are sufficient for accurate prediction of paraspinal muscle activity during functional activities. We used biplanar radiographs and marker-based motion capture, ground reaction force, and electromyography (EMG) data from two patients with mild and moderate thoracolumbar AIS (Cobb angles: 21° and 45°, respectively) during standing while holding two weights in front (reference position), walking, running, and object lifting. Using a fully automated approach, 3D spinal shape was extracted from the radiographs. Geometrically personalized OpenSim-based MSK models were created by deforming the spine of pre-scaled full-body models of children/adolescents. Simulations were performed using an experimentally controlled backward approach. Differences between model predictions and EMG measurements of paraspinal muscle activity (both expressed as a percentage of the reference position values) at three different locations around the scoliotic main curve were quantified by root mean square error (RMSE) and cross-correlation (XCorr). Predicted and measured muscle activity correlated best for mild AIS during object lifting (XCorr's ≥ 0.97), with relatively low RMSE values. For moderate AIS as well as the walking and running activities, agreement was lower, with XCorr reaching values of 0.51 and comparably high RMSE values. This study demonstrates that static optimization alone seems not appropriate for predicting muscle activity in AIS patients, particularly in those with more than mild deformations as well as when performing upright activities such as walking and running.

Active Site Descriptors from 95Mo NMR Signatures of Silica-Supported Mo-Based Olefin Metathesis Catalysts.

The olefin metathesis activity of silica-supported molybdenum oxides depends strongly on metal loading and preparation conditions, indicating that the nature and/or amounts of the active sites vary across compositionally similar catalysts. This is illustrated by comparing Mo-based (pre)catalysts prepared by impregnation (2.5-15.6 wt % Mo) and a model material (2.3 wt % Mo) synthesized via surface organometallic chemistry (SOMC). Analyses of FTIR, UV-vis, and Mo K-edge X-ray absorption spectra show that these (pre)catalysts are composed predominantly of similar isolated Mo dioxo sites. However, they exhibit different reaction properties in both liquid and gas-phase olefin metathesis with the SOMC-derived catalyst outperforming a classical catalyst of a similar Mo loading by ×1.5-2.0. Notably, solid-state 95Mo NMR analyses leveraging state-of-the-art high-field (28.2 T) measurement conditions resolve four distinct surface Mo dioxo sites with distributions that depend on the (pre)catalyst preparation methods. The intensity of a specific deshielded 95Mo NMR signal, which is most prominent in the SOMC-derived catalyst, is linked to reducibility and catalytic activity. First-principles calculations show that 95Mo NMR parameters directly manifest the local strain and coordination environment: acute (SiO-Mo(O)2-OSi) angles and low coordination numbers at Mo lead to highly deshielded 95Mo chemical shifts and small quadrupolar coupling constants, respectively. Natural chemical shift analyses relate the 95Mo NMR signature of strained species to low LUMO energies, which is consistent with their high reducibility and corresponding reactivity. The 95Mo chemical shifts of supported Mo dioxo sites are thus linked to their specific electronic structures, providing a powerful descriptor for their propensity toward reduction and formation of active sites.

Catabolism highly influences ICU-acquired hypernatremia in a mainly trauma and surgical cohort.

PURPOSE: To further analyse causes and effects of ICU-acquired hypernatremia. METHODS: This retrospective, single-centre study, analysed 994 patients regarding ICU-acquired hypernatremia. Non-hypernatremic patients (n = 617) were compared to early-hypernatremic (only before ICU-day 4; n = 87), prolonged-hypernatremic (before and after ICU-day 4; n = 169) and late-hypernatremic patients (only after ICU-day 4; n = 121). Trends in glomerular filtration rate (eGFR), urea-to-creatinine ratio (UCR), fraction of urea in total urine osmolality and urine sodium were compared. Risk factors for i) the development of hypernatremia and ii) mortality were determined. RESULTS: Thirty-eight percent (n = 377) developed ICU-acquired hypernatremia. Specifically in the prolonged- and late-group, decreased eGFRs and urine sodium but increased UCR and fractions of urea in urine osmolality were present. Decreased eGFR was a risk factor for the development of hypernatremia in all groups; disease severity and increased catabolism particularly in the prolonged- and late-hypernatremic group. Increased age, SAPS-III and signs of catabolism but not the development of hypernatremia itself was identified as significant risk factor for mortality. CONCLUSIONS: Late- and prolonged-hypernatremia is highly related to an increased protein metabolism. Besides excessive catabolism, initial disease severity and a decrease in renal function must be considered when confronted with ICU-acquired hypernatremia.

Candida auris in Austria-What Is New and What Is Different.

Candida auris is a novel and emerging pathogenic yeast which represents a serious global health threat. Since its first description in Japan 2009, it has been associated with large hospital outbreaks all over the world and is often resistant to more than one antifungal drug class. To date, five C. auris isolates have been detected in Austria. Morphological characterization and antifungal susceptibility profiles against echinocandins, azoles, polyenes and pyrimidines, as well as the new antifungals ibrexafungerp and manogepix, were determined. In order to assess pathogenicity of these isolates, an infection model in Galleria mellonella was performed and whole genome sequencing (WGS) analysis was conducted to determine the phylogeographic origin. We could characterize four isolates as South Asian clade I and one isolate as African clade III. All of them had elevated minimal inhibitory concentrations to at least two different antifungal classes. The new antifungal manogepix showed high in vitro efficacy against all five C. auris isolates. One isolate, belonging to the African clade III, showed an aggregating phenotype, while the other isolates belonging to South Asian clade I were non-aggregating. In the Galleria mellonella infection model, the isolate belonging to African clade III exhibited the lowest in vivo pathogenicity. As the occurrence of C. auris increases globally, it is important to raise awareness to prevent transmission and hospital outbreaks.

Biomechanical factors associated with non-specific low back pain in adults: A systematic review.

Low back pain (LBP) can result in increased direct medical and non-medical costs to patients, employers, and health care providers. This systematic review aimed to provide a better understanding of the biomechanical factors associated with chronic non-specific LBP in adults. SCOPUS, ScienceDirect, MEDLINE, and Web of Science databases were searched. In total, 26 studies were included and significant differences were noted between healthy controls and LBP patients in various motion. Biomechanical factors among adults with non-specific LBP were altered and differed as compared to healthy controls in various motion might be to compensate the pain during those motions. This review highlighted the biomechanical differences across those with non-specific LBP and healthy adults. Both groups showed a similar level of pain during functional tasks but LBP patients suffered from a moderate level of disability. Future studies should not rely on questionnaire-based pain scale only. The biomechanical factors summarized in this review can be used to diagnose non-specific LBP accurately, and as modifiable targets for exercise-based intervention.

Elucidation of radical- and oxygenate-driven paths in zeolite-catalysed conversion of methanol and methyl chloride to hydrocarbons.

Understanding hydrocarbon generation in the zeolite-catalysed conversions of methanol and methyl chloride requires advanced spectroscopic approaches to distinguish the complex mechanisms governing C-C bond formation, chain growth and the deposition of carbonaceous species. Here operando photoelectron photoion coincidence (PEPICO) spectroscopy enables the isomer-selective identification of pathways to hydrocarbons of up to C14 in size, providing direct experimental evidence of methyl radicals in both reactions and ketene in the methanol-to-hydrocarbons reaction. Both routes converge to C5 molecules that transform into aromatics. Operando PEPICO highlights distinctions in the prevalence of coke precursors, which is supported by electron paramagnetic resonance measurements, providing evidence of differences in the representative molecular structure, density and distribution of accumulated carbonaceous species. Radical-driven pathways in the methyl chloride-to-hydrocarbons reaction(s) accelerate the formation of extended aromatic systems, leading to fast deactivation. By contrast, the generation of alkylated species through oxygenate-driven pathways in the methanol-to-hydrocarbons reaction extends the catalyst lifetime. The findings demonstrate the potential of the presented methods to provide valuable mechanistic insights into complex reaction networks.

Spatial distribution of erector spinae activity is related to task-specific pain-related fear during a repetitive object lifting task.

Fear-avoidance beliefs, particularly the fear of lifting with a flexed spine, are associated with reduced spinal motion during object lifting. Low back pain patients thereby also showed potentially clinically relevant changes in the spatial distribution of back muscle activity, but it remains unknown whether such associations are also present in pain-free individuals. This cross-sectional observational study investigated the relationship between fear-avoidance beliefs and the spatial distribution of lumbar paraspinal muscle activity in pain-free individuals during a repetitive lifting task. Thirty participants completed two pain-related fear questionnaires and performed 25 repetitions of lifting a 5 kg-box from a lower to an upper shelf and back, while multi-channel electromyographic signals were recorded bilaterally from the lumbar erector spinae muscles. Changes in spatial distribution were defined as the differences in vertical position of the weighted centroids of muscle activity (centroid shift) between the first and last few repetitions. Linear regression analyses were performed to examine the relationships between centroid shift and fear-avoidance belief scores. Fear of lifting an object with a flexed spine was negatively associated with erector spinae activity centroid shift (R2 adj. = 0.1832; p = 0.045), which might be an expression of behavioral alterations to prevent the back from possible harm.

Skin marker-based subject-specific spinal alignment modeling: A feasibility study.

Musculoskeletal models have the potential to improve diagnosis and optimize clinical treatment by predicting accurate outcomes on an individual basis. However, the subject-specific modeling of spinal alignment is often strongly simplified or is based on radiographic assessments, exposing subjects to unnecessary radiation. We therefore developed and introduced a novel skin marker-based approach for modeling subject-specific spinal alignment and evaluated its feasibility by comparing the predicted L1/L2 spinal loads during various functional activities with the loads predicted by the generically scaled models as well as with in vivo measured data obtained from the OrthoLoad database. Spinal loading simulations resulted in considerably higher compressive forces for both scaling approaches over all simulated activities, and AP shear forces that were closer or similar to the in vivo data for the subject-specific approach during upright standing activities and for the generic approach during activities that involved large flexions. These results underline the feasibility of the proposed method and associated workflow for inter- and intra-subject investigations using musculoskeletal simulations. When implemented into standard model scaling workflows, it is expected to improve the accuracy of muscle activity and joint loading simulations, which is crucial for investigations of treatment effects or pathology-dependent deviations.

The Stoop-Squat-Index: a simple but powerful measure for quantifying whole-body lifting behavior.

BACKGROUND: Most of the studies evaluating lifting behavior only focus on very localized parameters such as lumbar spine flexion, while evaluations of whole-body strategies are largely lacking. To enable relatively simple evaluations of whole-body strategies, this study aimed at developing a novel index for quantifying the stoop-squat behavior, and to establish normative values of the index for healthy pain-free adults. METHODS: A novel index, the Stoop-Squat-Index, was developed, which describes the proportion between trunk forward lean and lower extremity joint flexion, with possible values ranging from 0 (full squat lifting) to 100 (full stoop lifting). To enable the interpretation of the index in a real-life setting, normative values for lifting a moderately-weighted object (15-kg-box) with a full squat and a full stoop technique were established using motion capture data from 30 healthy pain-free individuals that underwent motion analysis of squat and stoop lifting in the context of a previously conducted study. RESULTS: The results showed mean index values of lower than 30 and higher than 90 for the most relevant phases of the squat and stoop movements, respectively, with mean index values differing significantly from each other for the full duration of the lifting phases. CONCLUSIONS: The main advantages of the index are that it is simple to calculate and can not only be derived from motion capture data but also from conventional video recordings, which enables large-scale in-field measurements with relatively low expenditure. When used in combination with lumbar spine flexion measurements, the index can contribute important information, which is necessary for comprehensively evaluating whole-body lifting strategies and to shed more light on the debate over the connection between lifting posture and back complaints.

From Stoop to Squat: A Comprehensive Analysis of Lumbar Loading Among Different Lifting Styles.

Lifting up objects from the floor has been identified as a risk factor for low back pain, whereby a flexed spine during lifting is often associated with producing higher loads in the lumbar spine. Even though recent biomechanical studies challenge these assumptions, conclusive evidence is still lacking. This study therefore aimed at comparing lumbar loads among different lifting styles using a comprehensive state-of-the-art motion capture-driven musculoskeletal modeling approach. Thirty healthy pain-free individuals were enrolled in this study and asked to repetitively lift a 15 kg-box by applying 1) a freestyle, 2) a squat and 3) a stoop lifting technique. Whole-body kinematics were recorded using a 16-camera optical motion capture system and used to drive a full-body musculoskeletal model including a detailed thoracolumbar spine. Continuous as well as peak compressive, anterior-posterior shear and total loads (resultant load vector of the compressive and shear load vectors) were calculated based on a static optimization approach and expressed as factor body weight (BW). In addition, lumbar lordosis angles and total lifting time were calculated. All parameters were compared among the lifting styles using a repeated measures design. For each lifting style, loads increased towards the caudal end of the lumbar spine. For all lumbar segments, stoop lifting showed significantly lower compressive and total loads (-0.3 to -1.0BW) when compared to freestyle and squat lifting. Stoop lifting produced higher shear loads (+0.1 to +0.8BW) in the segments T12/L1 to L4/L5, but lower loads in L5/S1 (-0.2 to -0.4BW). Peak compressive and total loads during squat lifting occurred approximately 30% earlier in the lifting cycle compared to stoop lifting. Stoop lifting showed larger lumbar lordosis range of motion (35.9 ± 10.1°) than freestyle (24.2 ± 7.3°) and squat (25.1 ± 8.2°) lifting. Lifting time differed significantly with freestyle being executed the fastest (4.6 ± 0.7 s), followed by squat (4.9 ± 0.7 s) and stoop (5.9 ± 1.1 s). Stoop lifting produced lower total and compressive lumbar loads than squat lifting. Shear loads were generally higher during stoop lifting, except for the L5/S1 segment, where anterior shear loads were higher during squat lifting. Lifting time was identified as another important factor, considering that slower speeds seem to result in lower loads.

ICU-Admission Hyperphosphataemia Is Related to Shock and Tissue Damage, Indicating Injury Severity and Mortality in Polytrauma Patients.

Hyperphosphataemia can originate from tissue ischaemia and damage and may be associated with injury severity in polytrauma patients. In this retrospective, single-centre study, 166 polytrauma patients (injury severity score (ISS) ≥ 16) primarily requiring intensive care unit (ICU) treatment were analysed within a five-year timeframe. ICU-admission phosphate levels defined a hyperphosphataemic (>1.45 mmol/L; n = 56) opposed to a non-hyperphosphataemic group (n = 110). In the hyperphosphataemic group, injury severity was increased (ISS median and IQR: 38 (30-44) vs. 26 (22-34); p < 0.001), as were signs of shock (lactate, resuscitation requirements), tissue damage (ASAT, ALAT, creatinine) and lastly in-hospital mortality (35.7% vs. 5.5%; p < 0.001). Hyperphosphataemia at ICU admission was shown to be a risk factor for mortality (1.46-2.10 mmol/L: odds ratio (OR) 3.96 (95% confidence interval (CI) 1.03-15.16); p = 0.045; >2.10 mmol/L: OR 12.81 (CI 3.45-47.48); p < 0.001) and admission phosphate levels alone performed as good as injury severity score (ISS) in predicting in-hospital mortality (area under the ROC curve: 0.811 vs. 0.770; p = 0.389). Hyperphosphataemia at ICU admission is related to tissue damage and shock and indicates injury severity and subsequent mortality in polytrauma patients. Admission phosphate levels represent an easily feasible yet strong predictor for in-hospital mortality.

Absence of Stress Hyperglycemia Indicates the Most Severe Form of Blunt Liver Trauma.

BACKGROUND: Stress hyperglycemia is common in trauma patients. Increasing injury severity and hemorrhage trigger hepatic gluconeogenesis, glycogenolysis, peripheral and hepatic insulin resistance. Consequently, we expect glucose levels to rise with injury severity in liver, kidney and spleen injuries. In contrast, we hypothesized that in the most severe form of blunt liver injury, stress hyperglycemia may be absent despite critical injury and hemorrhage. METHODS: All patients with documented liver, kidney or spleen injuries, treated at a university hospital between 2000 and 2020 were charted. Demographic, laboratory, radiological, surgical and other data were analyzed. RESULTS: A total of 772 patients were included. In liver (n = 456), spleen (n = 375) and kidney (n = 152) trauma, an increase in injury severity past moderate to severe (according to the American Association for the Surgery of Trauma, AAST III-IV) was associated with a concomitant rise in blood glucose levels independent of the affected organ. While stress-induced hyperglycemia was even more pronounced in the most severe forms (AAST V) of spleen (median 10.7 mmol/L, p < 0.0001) and kidney injuries (median 10.6 mmol/L, p = 0.004), it was absent in AAST V liver injuries, where median blood glucose level even fell (5.6 mmol/L, p < 0.0001). CONCLUSIONS: Absence of stress hyperglycemia on hospital admission could be a sign of most severe liver injury (AAST V). Blood glucose should be considered an additional diagnostic criterion for grading liver injury.

Spinal Palpation Error and Its Impact on Skin Marker-Based Spinal Alignment Measurement in Adult Spinal Deformity.

Spinal alignment measurement in spinal deformity research has recently shifted from using mainly two-dimensional static radiography toward skin marker-based motion capture approaches, allowing three-dimensional (3D) assessments during dynamic conditions. The validity and accuracy of such skin marker-based methods is highly depending on correct marker placement. In this study we quantified, for the first time, the 3D spinal palpation error in adult spinal deformity (ASD) and compared it to the error in healthy spines. Secondly, the impact of incorrect marker placement on the accuracy of marker-based spinal alignment measurement was investigated. 3D, mediolateral and inferosuperior palpation errors for thoracolumbar and lumbar vertebral levels were measured on biplanar images by extracting 3D positions of skin-mounted markers and their corresponding anatomical landmarks in 20 ASD and 10 healthy control subjects. Relationships were investigated between palpation error and radiographic spinal alignment (lordosis and scoliosis), as well as body morphology [BMI and soft tissue (ST) thickness]. Marker-based spinal alignment was measured using a previously validated method, in which a polynomial is fit through the marker positions of a motion trial and which allows for radiograph-based marker position correction. To assess the impact of palpation error on spinal alignment measurement, the agreement was investigated between lordosis and scoliosis measured by a polynomial fit through, respectively, (1) the uncorrected marker positions, (2) the palpation error-corrected (optimal) marker positions, and (3) the anatomically corrected marker positions (toward the vertebral body), and their radiographic equivalents expressed as Cobb angles (ground truth), using Spearman correlations and root mean square errors (RMSE). The results of this study showed that, although overall accuracy of spinal level identification was similar across groups, mediolateral palpation was less accurate in the ASD group (ASDmean: 6.8 mm; Controlmean: 2.5 mm; p = 0.002). Significant correlations with palpation error indicated that determining factors for marker misplacement were spinal malalignment, in particular scoliotic deformity (r = 0.77; p < 0.001), in the ASD group and body morphology [i.e., increased BMI (r s = 0.78; p = 0.008) and ST thickness (r s = 0.66; p = 0.038)] in healthy spines. Improved spinal alignment measurements after palpation error correction, shows the need for radiograph-based marker correction methods, and therefore, should be considered when interpreting spinal kinematics.

Accuracy of training blood volume quantification using a visual estimation tool.

BACKGROUND: We investigated whether the use of a specially designed visual estimation tool may improve accuracy in quantifying blood volumes related to surface spreading. METHODS: A prospective, paired-control, single-blinded experimental study was performed at a medical university. Anesthesiologists and emergency medical personnel estimated various blood volumes on surfaces with varying absorptivity (carpet, towel, polyvinyl chloride, wooden flooring) in an experimental setting. We assessed the sensitivity of training blood volume quantification using a self-designed visual estimation tool by comparing the accuracy of visual blood volume estimations before and after practical training with the tool. RESULTS: A total of 352 estimations by 44 participants were evaluated. Accurate estimations improved significantly from pre-training to post-training (P<0.05). The sensitivity of blood volume quantification was 33.0% after training with the visual estimation tool. Estimations did not depend on age, profession, gender or years of the estimator's professional experience. CONCLUSIONS: Training with a visual estimation tool by professional rescuers can improve the estimation accuracy of blood volumes spread on surfaces with varying absorptivity.

Early ICU-acquired hypernatraemia is associated with injury severity and preceded by reduced renal sodium and chloride excretion in polytrauma patients.

PURPOSE: To further elucidate the origin of early ICU-acquired hypernatraemia. MATERIAL AND METHODS: In this retrospective single-centre study, polytrauma patients requiring ICU treatment were analysed. RESULTS: Forty-eight (47.5%) of 101 included polytrauma patients developed hypernatraemia within the first 7 days on ICU. They were more severely ill as described by higher SAPS III, ISS, daily SOFA scores and initial norepinephrine requirements as well as longer requirements of mechanical ventilation and ICU treatment in general. The development of hypernatraemia was neither attributable to fluid- or sodium-balances nor renal impairment. Although lower in the hypernatraemic group from day 4 onwards, median creatinine clearances were sufficiently high throughout the observation period. However, in the hypernatraemic group, urine sodium and chloride concentrations prior to the evolvement of hypernatraemia (56 (27-87) mmol/l and 39 (23-77) mmol/l) were significantly decreased when compared to i) the time after developing hypernatraemia (94 (58-134) mmol/l and 78 (36-115) mmol/l; p < 0.001) and ii) the non-hypernatraemic group in general (101 (66-143) mmol/l and 75 (47-109) mmol/l; p < 0.001). CONCLUSIONS: Early ICU-acquired hypernatraemia is associated with injury severity and preceded by reduced renal sodium and chloride excretion in polytrauma patients.