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The National Aeronautics and Space Administration (NASA)’s Operation IceBridge (OIB) was a 13-year (2009–2021) airborne mission to survey land and sea ice across the Arctic, Antarctic, and Alaska. Here, we review OIB’s goals, instruments, campaigns, key scientific results, and implications for future investigations of the cryosphere. OIB’s primary goal was to use airborne laser altimetry to bridge the gap in fine-resolution elevation measurements of ice from space between the conclusion of NASA’s Ice, Cloud, and land Elevation Satellite (ICESat; 2003–2009) and its follow-on, ICESat-2 (launched 2018). Additional scientific requirements were intended to contextualize observed elevation changes using a multisensor suite of radar sounders, gravimeters, magnetometers, and cameras. Using 15 different aircraft, OIB conducted 968 science flights, of which 42% were repeat surveys of land ice, 42% were surveys of previously unmapped terrain across the Greenland and Antarctic ice sheets, Arctic ice caps, and Alaskan glaciers, and 16% were surveys of sea ice. The combination of an expansive instrument suite and breadth of surveys enabled numerous fundamental advances in our understanding of the Earth’s cryosphere. For land ice, OIB dramatically improved knowledge of interannual outlet-glacier variability, ice-sheet, and outlet-glacier thicknesses, snowfall rates on ice sheets, fjord and sub-ice-shelf bathymetry, and ice-sheet hydrology. Unanticipated discoveries included a reliable method for constraining the thickness within difficult-to-sound incised troughs beneath ice sheets, the extent of the firn aquifer within the Greenland Ice Sheet, the vulnerability of many Greenland and Antarctic outlet glaciers to ocean-driven melting at their grounding zones, and the dominance of surface-melt-driven mass loss of Alaskan glaciers. For sea ice, OIB significantly advanced our understanding of spatiotemporal variability in sea ice freeboard and its snow cover, especially through combined analysis of fine-resolution altimetry, visible imagery, and snow radar measurements of the overlying snow thickness. Such analyses led to the unanticipated discovery of an interdecadal decrease in snow thickness on Arctic sea ice and numerous opportunities to validate sea ice freeboards from satellite radar altimetry. While many of its data sets have yet to be fully explored, OIB’s scientific legacy has already demonstrated the value of sustained investment in reliable airborne platforms, airborne instrument development, interagency and international collaboration, and open and rapid data access to advance our understanding of Earth’s remote polar regions and their role in the Earth system.

We present the Warm Ice Sounding Explorer (WISE), a low-frequency (2.5 MHz) radar for the sounding of temperate ice. WISE deployment in southern Alaska in 2008 and 2012 provides comprehensive measurements of glacier thickness, reveals deep valleys beneath glaciers and the full extent of zones grounded below sea level. The east branch of Columbia Glacier is deeper that its main branch and remains below sea level 20 km farther inland. Ice is 1000 m deep on Tazlina Glacier. On Bering glacier, two sills separate three deep bed depressions (>1200 m) that coincide with the dynamic balance lines during surges. The piedmont lobe of Malaspina Glacier and the lower reaches of Hubbard Glacier are entirely grounded below sea level 40 and 10 km, respectively, from their termini. Knowledge of ice thickness in these regions helps better understand their glacier dynamics, mass balance, and impact on sea level. Key Points Low frequency radar sounding works extremely well in Alaska Ice is much thicker than suggested by limited surveys Data reveals full extent of areas grounded below sea level ©2013. American Geophysical Union. All Rights Reserved.

Introduction: It is debated whether early trauma-induced coagulopathy (TIC) in severely injured patients reflects disseminated intravascular coagulation (DIC) with a fibrinolytic phenotype, acute coagulopathy of trauma shock (ACoTS) or yet other entities. This study investigated the prevalence of overt DIC and ACoTS in trauma patients and characterized these conditions based on their biomarker profiles.Methods: An observational study was carried out at a single Level I Trauma Center. Eighty adult trauma patients (≥18 years) who met criteria for full trauma team activation and had an arterial cannula inserted were included. Blood was sampled a median of 68 minutes (IQR 48 to 88) post-injury. Data on demography, biochemistry, injury severity score (ISS) and mortality were recorded. Plasma/serum was analyzed for biomarkers reflecting tissue/endothelial cell/glycocalyx damage (histone-complexed DNA fragments, Annexin V, thrombomodulin, syndecan-1), coagulation activation/inhibition (prothrombinfragment 1+2, thrombin/antithrombin-complexes, antithrombin, protein C, activated protein C, endothelial protein C receptor, protein S, tissue factor pathway inhibitor, vWF), factor consumption (fibrinogen, FXIII), fibrinolysis (D-dimer, tissue-type plasminogen activator, plasminogen activator inhibitor-1) and inflammation (interleukin (IL)-6, terminal complement complex (sC5b-9)). Comparison of patients stratified according to the presence or absence of overt DIC (International Society of Thrombosis and Hemostasis (ISTH) criteria) or ACoTS (activated partial thromboplastin time (APTT) and/or international normalized ratio (INR) above normal reference).Results: No patients had overt DIC whereas 15% had ACoTS. ACoTS patients had higher ISS, transfusion requirements and mortality (all P < 0.01) and a biomarker profile suggestive of enhanced tissue, endothelial cell and glycocalyx damage and consumption coagulopathy with low protein C, antithrombin, fibrinogen and FXIII levels, hyperfibrinolysis and inflammation (all P < 0.05). Importantly, in non-ACoTS patients, apart from APTT/INR, higher ISS correlated with biomarkers of enhanced tissue, endothelial cell and glycocalyx damage, protein C activation, coagulation factor consumption, hyperfibrinolysis and inflammation, that is, resembling that observed in patients with ACoTS.Conclusions: ACoTS and non-ACoTS may represent a continuum of coagulopathy reflecting a progressive early evolutionarily adapted hemostatic response to the trauma hit and both are parts of TIC whereas DIC does not appear to be part of this early response. [ABSTRACT FROM AUTHOR]

Objectives: Deep learning is in this study used through convolutional neural networks (CNN) to the determination of vocal fold nodules. Through high-speed video (HSV) images and computer-assisted tools, a comparison of convolutional neural network models and their accuracy will be presented., Methods: The data have been collected by an Ear Nose Throat (ENT) specialist with a 90° rigid scope in the years from 2007 to 2019, where 15.732 high-speed videos have been collected from 7909 patients. A total of 4000 images have been carefully selected, 2000 images were of normal vocal folds and 2000 images were of vocal folds with varying degrees of vocal fold nodules. These images were then split into training-, validation-, and testing-data set, for use with a CNN model with 5 layers (CNN5) and compared to other models: VGG19, MobileNetV2, and Inception-ResNetV2. To compare the neural network models, the following evaluation metrics have been calculated: accuracy, sensitivity, specificity, precision, and negative predictive values., Results: All the trained CNN models have shown high accuracy when applied to the test set. The accuracy is 97.75%, 83.5%, 91.5%, and 89.75%, for CNN5, VGG19, MobileNetV2, and InceptionResNetV2, respectively., Conclusions: Precision was identified as the most relevant performance metric for a study that focuses on the classification of vocal fold nodules. The highest performing model was MobilNetV2 with a precision of 97.7%. The average accuracy across all 4 neural networks was 90.63% showing that neural networks can be used for classifying vocal fold nodules in a clinical setting., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The entire glottis has mostly been the focus in the tracking of the vocal folds, both manually and automatically. From a treatment point of view, the various regions of the glottis are of specific interest. The aim of the study was to test if it was possible to supplement an existing convolutional neural network (CNN) with post-network calculations for the localization and quantification of posterior glottal gaps during phonation, usable for vocal fold function analysis of e.g. laryngopharyngeal reflux findings. 30 subjects/videos with insufficient closure in the rear glottal area and 20 normal subjects/videos were selected from our database, recorded with a commercial high-speed video setup (HSV with 4000 frames per second), and segmented with an open-source CNN for validating voice function. We made post-network calculations to localize and quantify the 10% and 50% distance lines from the rear part of the glottis. The results showed a significant difference using the algorithm at the 10% line distance between the two groups of p < 0.0001 and no difference at 50%. These novel results show that it is possible to use post-network calculations on CNNs for the localization and quantification of posterior glottal gaps., (© 2023. The Author(s).)

Adolescence is a challenging time of change in voicing, normally and in pathology. An increased focus on voice production in relation to genetics can expand our knowledge of the onset of puberty and voice change. Our aim with this review was to connect research of genetics to voice production in adolescence. We need further understanding of the developmental background of voice in childhood and adolescence, because many genetic multi handicaps include voice production. Genetic development related to voice production was the focus in a search made by the Royal English Society of Medicine, with only a few results. We supplemented with references to genetic studies of adults and animals as well as adjacent areas of voice production. The genetic development of voice production is steered from the hypothalamus probably related to growth hormone. The genetic voice production in adults form the basis for understanding development. Some research results were found related to the pubertal steps. The findings are important in the future, using advanced voice analysis and artificial intelligence methods in patients with Multi handicaps., Competing Interests: The material is not published previously and will not be submitted for publication elsewhere. No conflict of interest relevant to this article were reported., (© 2021 Publishing services provided by Elsevier B.V. on behalf of King Faisal Specialist Hospital & Research Centre (General Organization), Saudi Arabia.)

To directly relate tissue abnormalities to dysfunctional voicing, it is decisive to temporally resolve the vocal fold movement during phonation on the microscopic level. High-speed video (HSV) can record the vocal folds with 2,000-4,000 fps. Ultra-high resolution optical coherence tomography can distinguish cellular layers with a resolution better than 5 μm within a tissue depth of 1 mm. In this review, we propose combining the two technologies and apply deep learning-based image segmentation to establish statistical evident and reproducible documentation for voice-related diseases.

Objective: Improvements in cancer treatment have resulted in an increased number of patients with metastatic spinal cord compression (MSCC). Because patients with MSCC often have a limited expected survival time, maintenance of a high functional level and quality of life are important. However, there is limited information about health-related quality of life (HRQoL) in patients with MSCC. The aim of this study was to examine the feasibility of routine assessment of HRQoL based on the Euroqol-5 dimensions (EQ-5D) questionnaire in a cohort of patients consecutively admitted for evaluation of acute symptoms of MSCC., Methods: From 1 January to 31 December 2011, 544 patients diagnosed with acute symptoms of MSCC were consecutively enrolled in a cohort study. All patients were evaluated through a centralized referral system at one treatment facility. Data were prospectively registered, the variables age, sex, primary oncologic diagnosis, Tokuhashi Revised score, EQ-5D score and treatment modality being recorded on admission. The study patients were treated conservatively with radiotherapy alone or with surgery and subsequent radiotherapy. The EQ-5D questionnaire was administered on admission (baseline) and 6, 12, 26 and 52 weeks after admission. Response rates, completion rates and HRQoL scores were analyzed by relevant subgroups. Response rates were based on all questionnaires returned regardless of whether or not they had been completed, whereas completion rates were based on fully completed questionnaires (i.e., containing responses to all five questions., Results: The mean age was 65 years (range, 20-95 years); 57% of the patients were men. The overall response rate to the Euroqol-5 dimensions (EQ-5D) questionnaires was 84% and the overall completion rate 72%. At baseline, mean EQ-5D scores were significantly lower for patients treated with surgery and subsequent radiotherapy 0.28 (95% CI, 0.19-0.36) than for those treated with radiotherapy alone 0.42 (95% CI, 0.38-0.46). At the one-year follow-up, the mean EQ-5D scores had improved to 0.71 (95% CI, 0.64-0.77) for patients treated with surgery and subsequent radiotherapy and 0.63 (95% CI, 0.56-0.70) for patients treated with radiotherapy alone., Conclusions: Measurement of HRQoL in patients consecutively admitted for evaluation of acute symptoms of MSCC is feasible and detects significant changes over time between treatment modalities and different strata of expected survival., (© 2016 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.)

Background: Haemorrhage remains a leading cause of morbidity and mortality in trauma patients. Fibrinogen is an essential endogenous component of haemostasis and the plasma level is associated with bleeding, transfusion and outcome. Fibrinogen concentrate is widely used to correct acquired hypofibrinogenaemia, recommended by several international guidelines for the treatment of trauma patients, but evidence is lacking regarding the treatment safety and efficacy. We aim to assess the efficacy and safety of an immediate pre-emptive first-line treatment with fibrinogen concentrate in patients with trauma haemorrhage in need of haemostatic resuscitation., Methods/design: This is a single-centre, randomized (1:1, active:placebo), placebo-controlled, double-blinded, investigator-initiated phase II trial. The trial population consists of 40 adult patients (>18 years) with traumatic, critical bleeding admitted to the Level 1 Trauma Centre at Rigshospitalet in Copenhagen, with immediate need for blood transfusion on arrival and an expected need for haemostatic resuscitation with multiple transfusions during the initial resuscitation. Patients will receive either pre-emptive administration of a bolus dose of 60-70 mg/kg fibrinogen concentrate (Riastap®) or placebo 0.9 % saline in equal volume to active treatment, both given as intravenous infusion blinded for the person administering the infusion. The primary end point is the change in thrombelastograph (TEG®) functional fibrinogen maximum amplitude in millimetres at 15 min after the intervention. The follow-up period on safety events and mortality will be until day 30. To detect a difference in the change from baseline to the 15-minute post-randomization measurement of 6-8 mm in TEG® functional fibrinogen maximum amplitude with a power of 0.90 and alpha of 0.05, we require 19 patients in each group. We have chosen to include 40 patients, 20 evaluable patients in each randomization group in case of attrition, in the present trial., Discussion: Patients considered to be included in the trial will temporarily have a compromised consciousness because of the acute, critical bleeding related to trauma, so scientific guardians will co-sign the informed consent form. Next of kin and the patients' general practitioner or the patients will co-sign as soon as possible. This trial will test whether immediate pre-emptive fibrinogen concentrate administered to adult trauma patients as first-line treatment of trauma haemorrhage will increase the clot strength as evaluated by thrombelastography, transfusion requirements and survival in patients receiving haemostatic resuscitation according to current standard of care., Trial Registration: EudraCT no. 2014-003978-16 (22/1 2015); ClinicalTrials.gov: NCT02344069 . Registered on 14 January 2015. Trial protocol version 4.2 (23-12-2014).

Fire-induced permafrost degradation is well documented in boreal forests, but the role of fires in initiating thermokarst development in Arctic tundra is less well understood. Here we show that Arctic tundra fires may induce widespread thaw subsidence of permafrost terrain in the first seven years following the disturbance. Quantitative analysis of airborne LiDAR data acquired two and seven years post-fire, detected permafrost thaw subsidence across 34% of the burned tundra area studied, compared to less than 1% in similar undisturbed, ice-rich tundra terrain units. The variability in thermokarst development appears to be influenced by the interaction of tundra fire burn severity and near-surface, ground-ice content. Subsidence was greatest in severely burned, ice-rich upland terrain (yedoma), accounting for ~50% of the detected subsidence, despite representing only 30% of the fire disturbed study area. Microtopography increased by 340% in this terrain unit as a result of ice wedge degradation. Increases in the frequency, magnitude, and severity of tundra fires will contribute to future thermokarst development and associated landscape change in Arctic tundra regions.

Subglacial discharge influences glacier basal motion and erodes and redeposits sediment. At tidewater glacier termini, discharge drives submarine terminus melting, affects fjord circulation, and is a central component of proglacial marine ecosystems. However, our present inability to track subglacial discharge and its variability significantly hinders our understanding of these processes. Here we report observations of hourly to seasonal variations in 1.5-10 Hz seismic tremor that strongly correlate with subglacial discharge but not with basal motion, weather, or discrete icequakes. Our data demonstrate that vigorous discharge occurs from tidewater glaciers during summer, in spite of fast basal motion that could limit the formation of subglacial conduits, and then abates during winter. Furthermore, tremor observations and a melt model demonstrate that drainage efficiency of tidewater glaciers evolves seasonally. Glaciohydraulic tremor provides a means by which to quantify subglacial discharge variations and offers a promising window into otherwise obscured glacierized environments.

Objective and Design: To elucidate whether platelets differentiate cytokine release following trauma, we prospectively measured three major platelet-derived cytokines in 213 trauma patients on hospital arrival., Methods: We measured plasma levels of the anti-inflammatory β-thromboglobulins (βTGs), transforming growth factor-β1 (TGFβ1) and the pro-inflammatory platelet factor 4 (PF4) cytokines. We also measured soluble glycoprotein VI (sGPVI), procoagulant platelet microparticles (PMPs) and white blood cell (WBC) counts, and evaluated in vitro platelet function in primary and secondary haemostasis by aggregometry and thromboelastometry, respectively. We evaluated associations of each cytokine by multivariate regression including injury severity score (ISS), WBC counts, sGPVI and platelet counts as explanatory variables., Results: Severely injured patients (ISS > 15) had higher levels of βTGs and TGFβ1 (both p < 0.01) but lower levels of PF4 (p = 0.02). GPVI and PMPs levels correlated with TGFβ1 and PF4 whereas we found no significant association between cytokine levels and measures of haemostasis. By multivariate regression, a high WBC count was associated with high levels of TGFβ1 (p = 0.01) and βTGs (p < 0.01) but with low levels of PF4 (p = 0.03)., Conclusion: Severely injured patients had higher levels of βTGs and TGFβ1 but lower levels of the PF4; a high WBC count predicted this anti-inflammatory profile of platelet cytokines.

Purpose: Improved survival among cancer patients and diverse conclusions from recent studies make it relevant to reassess the performance of the Tokuhashi Revised score and the Tomita score. The aim of this study was to validate and compare these two scoring systems in a recent and unselected cohort of patients with metastatic spinal cord compression (MSCC)., Methods: In 2011, we conducted a prospective cohort study of 544 patients who were consecutively admitted with MSCC to one treatment facility. Patients estimated survival were assessed with the Tokuhashi Revised score and the Tomita score and compared to the observed survival. We assessed how precise the scoring systems predicted survival with McNemar's test. The prognostic value was illustrated with Kaplan-Meier curves, and the individual prognostic components were analyzed with Cox regression analysis., Results: The mean age was 65 years (range 20-95), and 57 % of the patients were men. The majority of tumors were lung (23 %), prostate (21 %), and breast tumors (18 %). The overall precision of predicted survival was 58.7 % for the Tokuhashi Revised score and 52.9 % for the Tomita score. The observed survival in each of the scoring groups categorized by the scoring systems was statistically significantly different (p < 0.0001)., Conclusions: The Tokuhashi Revised score and the Tomita score are useful in categorizing patients into prognostic groups, and the individual components have important prognostic values. The Tokuhashi Revised score was most precise in predicting survival. However, due to the relatively low precision, we suggest that a modification of both scoring systems is necessary.

Background: Following activation, platelets release small vesicles called platelet-derived microparticles (PMPs). PMPs accelerate thrombin generation and thus clot formation at sites of injury by exposing the procoagulant membrane phospholipid phosphatidylserine (PS). The role of PMPs in coagulopathy and hemorrhage following trauma remains elusive. We hypothesized that low levels of PS-positive PMPs (PS + PMPs) would be associated with impaired clot formation., Methods: This is a prospective observational study of 210 trauma patients admitted directly to a Level 1 trauma center. Plasma levels of PS + PMPs were determined by flow cytometry. Coagulation status was assessed by rotational thrombelastometry, and impaired clot formation was defined by an α angle less than 63 degrees using the tissue factor-based EXTEM reagent. Transfusion requirement was assessed by number of units of red blood cells (RBCs) transfused within 24 hours of admission; platelet aggregation capacity was evaluated by the Multiplate assay; and injury severity was determined by the Injury Severity Score (ISS)., Results: The median ISS was 17, and blood samples were obtained after a median of 65 minutes following injury. Significantly lower levels of PS + PMPs were found in patients with impaired clot formation (p < 0.001). A low level of PS + PMPs was associated with a higher number of RBCs transfused during the initial 24 hours after admission (p < 0.03) when corrected for risk factors, for example, platelet count, hemoglobin level, and ISS. Platelet aggregation and PS + PMPs did not correlate significantly., Conclusion: Low levels of PMPs were associated with impaired clot formation in trauma patients at admission and also with the number of RBC transfusions. This suggests that PMPs may play an important and not previously investigated role in trauma-induced coagulopathy., Level of Evidence: Prognostic study, level III.

Purpose: We investigated whether the standard (ATLS) trauma protocol was adhered to in cases of suspected multi-traumatized pregnant patients and if serious injuries were overlooked. We hypothesized that radiographic studies would be less frequent in pregnant trauma patients., Methods: Forty-eight pregnant trauma patients were received in the observational period from January 2000 until May 2012; median age 30 years (range 16-40) and median stage of pregnancy 22 weeks (range 4-40). A retrospective review of patient files was performed., Results: Twenty-one percent of the pregnant trauma patients received a full trauma CT (T-CT) scan (head to pelvis), which was significantly lower than the percentage (62 %) of all primarily referred trauma patients in the same period. In the last four years of observation, the use of radiographic studies among pregnant trauma patients increased considerably. Along with this increase in the tendency to use T-CT over time during the observational period, there was also a rise in the median ISS. In addition, radiographic studies of the pelvis and abdominal area were performed only half as frequently as studies of the neck and chest., Conclusions: Adherence to the ATLS protocol in pregnant trauma patients was low in relation to radiographic studies but, in spite of this, no known significant injuries were missed. We found that a pelvic fracture seems to be predictive of a high risk of obstetric complications, such as intrauterine death or the need for cesarean section, but we were not able to relate trauma in general to a higher risk of cesarean section or premature birth.

Objective: To assess the association between Injury Severity Score (ISS) and subsequent risk of early retirement., Design: Observational cohort study with follow-up based on prospectively collected data. Hospital-based data were linked to national register data on pension reception and vital status., Setting: Level-one urban trauma centre., Participants: Patients aged 18-64 years entering the trauma centre in Copenhagen during 1999-2007 who were alive after three days were followed until early retirement, death or emigration., Main Outcome Measures: Primary outcome was early retirement, defined as receiving disability pension (unintentional) or voluntary early retirement pension (intentional) before the regular age of retirement (65 years). Relative risk of early retirement according to ISS (low, ISS 1-15 vs. high, ISS 16-75) was assessed using Cox proportional hazards regression, adjusted for age and gender., Results: Of all 6687 patients admitted to the trauma centre, a total of 1722 trauma patients were included and followed for a median of 6.2 years (interquartile range (IQR) 3.7-9.1). Of these, 1305 (75.8%) were males, median age was 35.0 years (IQR 25.4-46.5), and median ISS was 16 (IQR 9-25). Three hundred and twenty-two patients retired during follow-up. Patients with high ISS, compared to patients with low ISS, had an increased risk of early retirement, adjusted hazard ratio 2.60 (95% confidence interval (CI) 2.05-3.30; p<0.001). Relative increase in retirement risk was 1.04 (95% CI 1.03-1.05) per ISS point and 1.03 (95% CI 1.03-1.04) per year older. Gender was not found to be a significant risk factor (p=0.69). Five-year absolute risks of early retirement were 9.9% (95% CI 7.8-12.0%) for the low ISS group and 24.6% (95% CI 21.6-27.5%) for the high ISS group., Conclusions: The risk of early retirement is 2.6 times higher in severely injured patients (ISS 16-75) than the risk in low to moderately injured patients (ISS 1-15) and they have a high absolute 5-year risk as well. Early, targeted interventions to assist with return to work might be able to reduce this risk., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

We aimed to elucidate platelet function in trauma patients, as it is pivotal for hemostasis yet remains scarcely investigated in this population. We conducted a prospective observational study of platelet aggregation capacity in 213 adult trauma patients on admission to an emergency department (ED). Inclusion criteria were trauma team activation and arterial cannula insertion on arrival. Blood samples were analyzed by multiple electrode aggregometry initiated by thrombin receptor agonist peptide 6 (TRAP) or collagen using a Multiplate device. Blood was sampled median 65 min after injury; median injury severity score (ISS) was 17; 14 (7%) patients received 10 or more units of red blood cells in the ED (massive transfusion); 24 (11%) patients died within 28 days of trauma: 17 due to cerebral injuries, four due to exsanguination, and three from other causes. No significant association was found between aggregation response and ISS. Higher TRAP values were associated with death due to cerebral injuries (P < 0.01, when corrected for ISS and platelet counts), whereas lower platelet counts were associated with massive transfusion (P < 0.01, when corrected for ISS and aggregation). An aggregation value of 145 IU by TRAP significantly identified death due to cerebral injury (sensitivity 71% and specificity 76%, P < 0.01) by receiver operating characteristic-curve analysis; the corresponding value of platelet counts for massive transfusion was 189 × 10/l (sensitivity 86%, specificity 75%, P < 0.01). We concluded there was no simple relationship between platelet aggregation and injury severity. Our results indicate that high platelet aggregation values are associated with fatality of cerebral injury.

Background: Hemorrhage accounts for most preventable trauma deaths, but still the optimal strategy for hemostatic resuscitation remains debated., Study Design and Methods: This was a prospective study of adult trauma patients admitted to a Level I trauma center. Demography, Injury Severity Score (ISS), transfusion therapy, and mortality were registered. Hemostatic resuscitation was based on a massive transfusion protocol encompassing transfusion packages and thromboelastography (TEG)-guided therapy., Results: A total of 182 patients were included (75% males, median age 43 years, ISS of 17, 92% with blunt trauma). Overall 28-day mortality was 12% with causes of death being exsanguinations (14%), traumatic brain injury (72%, two-thirds expiring within 24 hr), and other (14%). One-fourth, 16 and 15% of the patients, received red blood cells (RBCs), plasma, or platelets (PLTs) within 2 hours from admission and 68, 71, and 75%, respectively, of patients transfused within 24 hours received the respective blood products within the first 2 hours. In patients transfused within 24 hours, the median number of blood products at 2 hours was 5 units of RBCs, 5 units of plasma, and 2 units of PLT concentrates. Nonsurvivors had lower clot strength by kaolin-activated TEG and TEG functional fibrinogen and lower kaolin-tissue factor-activated TEG α-angle and lysis after 30 minutes compared to survivors. None of the TEG variables were independent predictors of massive transfusion or mortality., Conclusion: Three-fourths of the patients transfused with plasma or PLTs within 24 hours received these in the first 2 hours. Hemorrhage caused 14% of the deaths. We introduced transfusion packages and early TEG-directed hemostatic resuscitation at our hospital 10 years ago and this may have contributed to reducing hemorrhagic trauma deaths., (© 2013 American Association of Blood Banks.)

Study Design: A retrospective cohort study of 2321 patients consecutively admitted to one center and diagnosed with acute symptoms of metastatic spinal cord compression (MSCC)., Objective: To assess the possible change in 1-year survival for patients with MSCC from year 2005 through 2010 with respect to the primary cancer diagnosis., Summary of Background Data: An increasing number of patients are offered surgical treatment for MSCC. Among the reasons for this development are high evidence clinical studies, improved surgical techniques, and an increasing number of patients being treated for an oncological condition. Preoperative scoring systems are routinely used in the evaluation of these patients, and the primary oncological diagnosis is an important variable in all these systems. To our knowledge, no studies in a large group of patients have assessed the change in survival in these patients. This is of relevance because such changes in survival could have implications on the scoring systems used in the preoperative evaluation., Methods: All patients referred to the university hospital, Rigshospitalet, suspected of acute symptoms caused by spinal metastases and diagnosed with MSCC from January 1, 2005, to December 31, 2010, were included in a retrospective cohort, n = 2321. For all patients primary tumor, treatment, and 1-year survival was registered., Results: The overall 1-year survival did not change significantly from 2005 to 2010, but there was a significant increase in 1-year survival for the subgroups of patients with lung cancer hazard ratio = 0.93 (P = 0.008, 95% CI: 0.83-0.98) and renal cancer hazard ratio = 0.77 (P = 0.004, 95% CI: 0.56-0.92)., Conclusion: Patients with MSCC from pulmonary and renal cancers experienced improved survival in the study period. No improvement was seen for patients with other oncological diagnoses. This corresponds to reports from oncological studies and could affect preoperative scoring systems.

It remains to be debated whether traumatic brain injury (TBI) induces a different coagulopathy than does non-TBI. This study investigated traditional coagulation tests, biomarkers of coagulopathy, and endothelial damage in trauma patients with and without TBI. Blood from 80 adult trauma patients was sampled (median of 68 min [IQR 48-88] post-injury) upon admission to our trauma center. Plasma/serum were retrospectively analyzed for biomarkers reflecting sympathoadrenal activation (adrenaline, noradrenaline), coagulation activation/inhibition and fibrinolysis (protein C, activated protein C, tissue factor pathway inhibitor, antithrombin, prothrombin fragment 1+2, thrombin/antithrombin complex, von Willebrand factor, factor XIII, d-dimer, tissue-type plasminogen activator, plasminogen activator inhibitor-1), immunology (interleukin [IL]6), endothelial cell/glycocalyx damage (soluble thrombomodulin, syndecan-1), and vasculogenesis (angiopoietin-1, -2). Patients were stratified according to: (1) isolated severe head/neck injuries (Abbreviated injury score [AIS]-head/neck ≥ 3, AIS-other<3) (isoTBI); (2) severe head/neck and extracranial injuries (AIS-head/neck ≥ 3, AIS-other>3) (sTBI+other); and (3) injuries without significant head/neck injuries (AIS-head/neck<3, including all AIS-other scores) (non-TBI). Twenty-three patients presented with isoTBI, 15 with sTBI+other and 42 with non-TBI. Acute coagulopathy of trauma shock, defined as activated partial thromboplastin time (APTT) and/or international normalized ratio (INR)>35 sec and>1.2, was found in 13%, 47%, and 5%, respectively (p=0.000). sTBI+other had significantly higher plasma levels of adrenaline, noradrenaline, annexin V, d-dimer, IL-6, syndecan-1, soluble thrombomodulin, and reduced protein C and factor XIII levels (all p<0.05). No significant biomarker differences were found between isoTBI and non-TBI patients. Injury severity scale (ISS) rather than the presence or absence of head/neck injuries determined the hemostatic and biomarker response to the injury. The coagulopathy identified thus reflected the severity of injury rather than its localization.

Our poor understanding of tidewater glacier dynamics remains the primary source of uncertainty in sea level rise projections. On the ice sheets, mass lost from tidewater calving exceeds the amount lost from surface melting. In Alaska, the magnitude of calving mass loss remains unconstrained, yet immense calving losses have been observed. With 20% of the global new-water sea level rise coming from Alaska, partitioning of mass loss sources in Alaska is needed to improve sea level rise projections. Here we present the first regionally comprehensive map of glacier flow velocities in Central Alaska. These data reveal that the majority of the regional downstream flux is constrained to only a few coastal glaciers. We find regional calving losses are 17.1 Gt a(-1), which is equivalent to 36% of the total annual mass change throughout Central Alaska.

Background: The level of soluble vascular endothelial growth factor receptor 1 (sVEGFR1) is increased in sepsis and strongly associated with disease severity and mortality. Endothelial activation and damage contribute to both sepsis and trauma pathology. Therefore, this study measured sVEGFR1 levels in trauma patients upon hospital admission hypothesizing that sVEGFR1 would increase with higher injury severity and predict a poor outcome., Methods: Prospective observational study of 80 trauma patients admitted to a Level I Trauma Centre. Data on demography, biochemistry, Injury Severity Score (ISS), transfusions and 30-day mortality were recorded and plasma/serum (sampled a median of 68 min (IQR 48-88) post-injury) was analyzed for sVEGFR1 and biomarkers reflecting sympathoadrenal activation (adrenaline, noradrenaline), tissue injury (histone-complexed DNA fragments, hcDNA), endothelial activation and damage (von Willebrand Factor Antigen, Angiopoietin-2, soluble endothelial protein C receptor, syndecan-1, soluble thrombomodulin (sTM)), coagulation activation/inhibition and fibrinolysis (prothrombinfragment 1 + 2, protein C, activated Protein C, tissue-type plasminogen activator, plasminogen activator inhibitor-1, D-dimer) and inflammation (interleukin-6). Spearman correlations and regression analyses to identify variables associated with sVEGFR1 and its predictive value., Results: Circulating sVEGFR1 correlated with injury severity (ISS, rho = 0.46), shock (SBE, rho = -0.38; adrenaline, rho = 0.47), tissue injury (hcDNA, rho = 0.44) and inflammation (IL-6, rho = 0.54) (all p < 0.01) but by multivariate linear regression analysis only lower SBE and higher adrenaline and IL-6 were independent predictors of higher sVEGFR1. sVEGFR1 also correlated with biomarkers indicative of endothelial glycocalyx degradation (syndecan-1, rho = 0.67), endothelial cell damage (sTM, rho = 0.66) and activation (Ang-2, rho = 0.31) and hyperfibrinolysis (tPA, rho = 0.39; D-dimer, rho = 0.58) and with activated protein C (rho = 0.31) (all p < 0.01). High circulating sVEGFR1 correlated with high early and late transfusion requirements (number of packed red blood cells (RBC) at 1 h (rho = 0.27, p = 0.016), 6 h (rho = 0.27, p = 0.017) and 24 h (rho = 0.31, p = 0.004) but was not associated with mortality., Conclusions: sVEGFR1 increased with increasing injury severity, shock and inflammation early after trauma but only sympathoadrenal activation, hypoperfusion, and inflammation were independent predictors of sVEGFR1 levels. sVEGFR1 correlated strongly with other biomarkers of endothelial activation and damage and with RBC transfusion requirements. Sympathoadrenal activation, shock and inflammation may be critical drivers of endothelial activation and damage early after trauma.

Aim: The aim of our study was to investigate the outcome in terms of 30-day survival and to determine whether preoperative factors could predict the outcome., Methods: All patients who underwent an emergency thoracotomy (ET) during the period 2000 to 2009 were included. The patients were divided into two groups: emergency department thoracotomy and operating room thoracotomy. Data on demographics, mechanism of injury, intraoperative data, Injury Severity Scores (ISS), probability of survival, signs of life, transportation time, indications, and outcome were collected., Results: Forty-four ETs were performed. The mechanisms of injury were penetrating in 28 (64%) and blunt in 16 (36%) cases. In the emergency department thoracotomy group, the survival was 45 versus 20% for penetrating and blunt trauma, respectively. The total survival was 33%. In the operating room thoracotomy group, the survival was 83%. The survivors had a significantly lower ISS and a higher calculated probability of survival. The calculated mean probability of survival was 44 and 84% in the emergency department thoracotomy and operating room thoracotomy groups, respectively. The actual survival was similar, with 33% in the emergency department thoracotomy group and 83% in the operating room thoracotomy group., Conclusions: The probability of survival and ISS are good predictors of survival in these patients and should be included in the future in order to make upcoming studies easier to compare. Patients with very high ISS or low probability of survival survived, justifying the procedure in our center.

Background: Severe injury activates the sympathoadrenal, hemostatic and inflammatory systems, but a maladapted response may contribute to a poor outcome. Soluble CD40L is a platelet-derived mediator that links inflammation, hemostasis and vascular dysfunction., Objectives: To investigate the association between the sCD40L level and tissue injury, shock, coagulopathy and mortality in trauma patients., Methods: A prospective, observational study of 80 trauma patients admitted to a Level I Trauma Center. Data on demography, biochemistry, Injury Severity Score (ISS) and 30-day mortality were recorded and admission plasma/serum analyzed for sCD40L and biomarkers reflecting sympathoadrenal activation (adrenaline, noradrenaline), tissue/endothelial cell/glycocalyx damage (histone-complexed DNA fragments [hcDNA], Annexin V, thrombomodulin and syndecan-1), coagulation activation/inhibition (PF1.2, TAT-complex, antithrombin, protein C, activated protein C, sEPCR, TFPI, von Willebrand factor [VWF], fibrinogen and factor [F] XIII), fibrinolysis (D-dimer, tissue plasminogen activator [tPA] and plasminogen activator inhibitor-1 [PAI-1]) and inflammation (interleukin-6 [IL-6] and sC5b-9). We compared patients stratified by median sCD40L level and investigated predictive values of sCD40L for mortality., Results: High circulating sCD40L was associated with enhanced tissue and endothelial damage (ISS, hcDNA, Annexin V, syndecan-1 and sTM), shock (pH, standard base excess), sympathoadrenal activation (adrenaline) and coagulopathy evidenced by reduced thrombin generation (PF1.2), hyperfibrinolysis (D-dimer), increased activated partial thromboplastin time (APTT) and inflammation (IL-6) (all P < 0.05). A higher ISS (P = 0.017), adrenaline (P = 0.049) and platelet count (P = 0.012) and lower pH (P =0.002) were associated with higher sCD40L by multivariate linear regression analysis. High circulating sCD40L (odds ratio [OR] 1.84 [95% CI 1.05-3.23], P = 0.034), high age (P = 0.002) and low Glasgow Coma Score (GCS) pre-hospital (P = 0.002) were independent predictors of increased mortality., Conclusions: High early sCD40L levels in trauma patients reflect tissue injury, shock, coagulopathy and sympathoadrenal activation and predict mortality. As sCD40L has pro-inflammatory activity and activates the endothelium, sCD40L may be involved in trauma-induced endothelial damage and coagulopathy., (© 2011 International Society on Thrombosis and Haemostasis.)

Background: Severe injury induces an acute coagulopathy associated with increased mortality. This study compared the Thrombelastography (TEG) and biomarker profiles upon admission in trauma patients., Methods: Prospective observational study of 80 trauma patients admitted to a Level I Trauma Centre. Data on demography, biochemistry including standard coagulation tests, hematology, transfusions, Injury Severity Score (ISS) and TEG were recorded. Retrospective analysis of thawed plasma/serum for biomarkers reflecting tissue injury (histone-complexed DNA fragments), sympathoadrenal activation (adrenaline, noradrenaline), coagulation activation/inhibition and fibrinolysis (sCD40L, protein C, activated Protein C, tissue-type plasminogen activator, plasminogen activator inhibitor-1, D-dimer, prothrombinfragment 1+2, plasmin/α2-antiplasmin complex, thrombin/antithrombin complex, tissue factor pathway inhibitor, antithrombin, von willebrand factor, factor XIII). Comparison of patients stratified according to ISS/TEG maximum clot strength. Linear regression analysis of variables associated with clot strength., Results: Trauma patients had normal (86%), hypercoagulable (11%) or hypocoagulable (1%) TEG clot strength; one had primary hyperfibrinolysis. Hypercoagulable patients had higher age, fibrinogen and platelet count (all p < 0.05), none had increased activated partial thromboplastin time (APTT) or international normalized ratio (INR) and none required massive transfusion (> 10 red blood cells the initial 24 h). Patients with normal or hypercoagulable TEG clot strength had comparable biomarker profiles, but the few patients with hypocoagulable TEG clot strength and/or hyperfibrinolysis had very different biomarker profiles.Increasing ISS was associated with higher levels of catecholamines, histone-complexed DNA fragments, sCD40L, activated protein C and D-dimer and reduced levels of non-activated protein C, antithrombin, fibrinogen and factor XIII (all p < 0.05). Fibrinogen and platelet count were associated independently with clot strength in patients with ISS ≤ 26 whereas only fibrinogen was associated independently with clot strength in patients with ISS > 26. In patients with ISS > 26, adrenaline and sCD40L were independently negatively associated with clot strength., Conclusions: Trauma patients displayed different coagulopathies by TEG and variables independently associated with clot strength changed with ISS. In the highest ISS group, adrenaline and sCD40L were independently negatively associated with clot strength indicating that these may contribute to acute coagulopathy.

This review studies the literature on the effects of parental presence during treatment of injured and acutely ill children. Parents wish to stay with their child, and clinicians increasingly find it beneficial, probably correlated with increased experience. Studies indicate that the treatment of the child is not compromised by parental presence but only a few quasi-randomised, quantitative studies have been published, and many circumstances concerning parental presence have not been investigated sufficiently.

The majority of patients undergoing damage control surgery initially receive prehospital treatment. Bleeding causes 40% of trauma deaths, half of which happen in the prehospital setting. Future research and improved treatment before hospital admission should focus on control of the bleeding, avoidance of hypothermia, minimising the time to definitive surgery, and a restrictive and goal directed therapy with regard to the intake of fluids. On occasion, lifesaving procedures could be performed during transport to the hospital.

The American College of Surgeons Committee on Trauma's Advanced Trauma Life Support Course is currently taught in 50 countries. The 8th edition has been revised following broad input by the International ATLS subcommittee. Graded levels of evidence were used to evaluate and approve changes to the course content. New materials related to principles of disaster management have been added. ATLS is a common language teaching one safe way of initial trauma assessment and management.

Background: Scientific knowledge on functional outcome after injury is limited. During the past decade, a variety of measures have been used at various moments in different study populations. Guidelines are needed to increase comparability between studies., Methods: A working group of the European Consumer Safety Association conducted a literature review of empirical studies into injury-related disability (1995-2005). We included injury from all levels of severity and selected studies using generic health status measures with both short-term and long-term follow up. The results were used as input for a consensus procedure toward the development of guidelines for defining the study populations, selecting the health status measures, selecting the timings of the assessments, and data collection procedures., Results: The group reached consensus on a common core of health status measures and assessment moments. The group advises to use a combination of EuroQol-5D and Health Utilities Mark III in all studies on injury-related disability. This combination covers all relevant health domains, is applicable in all kinds of injury populations and in widely different age ranges, provides a link with utility scores, and has several practical advantages (e.g., brevity, availability in different languages). For specific types of injury, the common core may be supplemented by injury-specific measures. The group advises a common core of assessments at 1, 2, 4, and 12 months after injury., Conclusions: Our guidelines should be tested and may lead to improved and more consistent epidemiologic data on the incidence, severity, and duration of injury-related disability.

The primary objective was to describe the methodological challenges and devise solutions to compare injury incidence across countries. The research design was a mixed methods study, consisting of a consultation with an expert group and comparison of injury surveillance systems and data from ten European countries. A subset of fractures, selected radiologically verifiable fractures and a method of checking the national representativeness of sample emergency department data were devised and are proposed for further development. These methodological considerations and developments will be further refined and tested and should prove useful tools for those who need to compare injury incidence data across countries.

In order to elucidate the history of scaphoid nonunion and to evaluate whether or not the problem has been solved, we have reviewed the literature from 1928 to 2003 for union rates, postoperative immobilization periods and complications of the different scaphoid bone grafting procedures. The outcomes of 5 246 scaphoid nonunions were evaluated in three treatment groups. In the first group involving nonvascularized bone grafting without internal fixation, we found a union rate of 80% (95% CI: 78-82) after an average immobilization period of 15 weeks. In the second group involving nonvascularized bone grafting with internal fixation, the figures were 84% (CI: 82-85) and 7 weeks, respectively. In the last group involving vascularized bone grafting with or without internal fixation, the figures were 91% (CI: 87-94) and 10 weeks, respectively. We found no prospective randomized studies comparing different operative treatments of scaphoid nonunion. We conclude that there still is a need for improvement in the treatment of scaphoid nonunion.

Little is known about the magnitude of hand injuries at national levels. This paper quantifies and characterises the incidence of hand injuries that require acute medical attention at Emergency Departments in The Netherlands and Denmark. Except for the incidence rate and the referral after treatment, the overall picture of hand injuries is similar for both countries: hand injuries show a peak for teenagers, result mainly from home and leisure accidents, are mainly caused by objects and falls, the majority affect fingers and result mainly in superficial injuries, open wounds and fractures, a small proportion of the victims is admitted into hospital. We conclude that hand injuries are a real burden to society and are worthwhile to be prevented with special attention for home and leisure accidents and occupational accidents. Data recording on the backgrounds of accidents and their long term consequences should be improved.

The MW (moment magnitude) 7.9 Denali fault earthquake on 3 November 2002 was associated with 340 kilometers of surface rupture and was the largest strike-slip earthquake in North America in almost 150 years. It illuminates earthquake mechanics and hazards of large strike-slip faults. It began with thrusting on the previously unrecognized Susitna Glacier fault, continued with right-slip on the Denali fault, then took a right step and continued with right-slip on the Totschunda fault. There is good correlation between geologically observed and geophysically inferred moment release. The earthquake produced unusually strong distal effects in the rupture propagation direction, including triggered seismicity.

Introduction: The aim of this study was to describe the initial care and management of trauma patients in Denmark., Material and Methods: A questionnaire was sent to all 64 hospitals in Denmark in July 1999. All responded. The questionnaire covered 81 questions., Results: The number of severely injured patients received by the hospitals was evenly distributed. Nine hospitals received more than 50 severely injured patients/year. Protocols for trauma care were available in 46 hospitals. Monitoring with ECG and pulse oximetry in the emergency room was possible in most hospitals. Most hospitals were also equipped to perform endotracheal intubation, chest tube drainage, surgical airway, and peritoneal lavage. Radiological and clinical laboratory services were available round the clock in most hospitals. Ultrasonography could be performed in 41 and CT in 36 hospitals. Three hospitals did not transfer patients to other facilities. An estimated quarter of the severely traumatised patients are transferred to a hospital with a higher level of trauma treatment., Conclusion: Many Danish hospitals receive trauma patients. However, a number of hospitals do not have the necessary organisation, clinical capabilities, or resources for trauma care. There is a need for regional and national guidelines for trauma care with recommendations ensuring early recognition of patients who may be sufficiently cared for in the local hospital, and those who require transfer to trauma centres for definitive care.

Introduction: The aim of this study was to describe changes in the use of accident and emergency departments in the Copenhagen Hospital Co-operation after restricted admittance to the accident and emergency department at a large Danish university hospital, Rigshospitalet (admittance only for patients transported by ambulance or presenting with a referral from a doctor)., Material and Methods: A retrospective study compared the number of patients treated in two periods, 1.7.1998 to 30.6.1999 and 1.7.1999 to 30.6.2000. Additional patient data were collected for the periods 1.7.1998 to 31.12.1998 and 1.7.1999 to 31.12.1999., Results: A 4% decrease was seen in the total number of patients treated at the accident and emergency departments. The decrease in the number of patients treated at the accident and emergency department at Rigshospitalet was 69%, whereas the accident and emergency department at Bispebjerg Hospital experienced a 53% rise., Discussion: The study showed good compliance in the local population after the restricted admittance to an accident and emergency department at a large university hospital. An expected total fall in the number of patients treated at the accident and emergency departments in the Copenhagen Hospital Co-operation could not be documented.

Functional Electrical Stimulation (FES) is a controlled use of electrical stimulation of muscle contractions to obtain function. FES is utilised today in the treatment of spinal cord injured individuals for diaphragmatic pacing, bladder and bowel management, ejaculation, walking and hand function, as well as conditioning. We present The Freehand System, which consists of implanted electrodes to arm and hand muscles. This system has now been implanted in the first two Nordic tetraplegics. Candidates are tetraplegics with C5-6 lesions. After implantation it may take 6-8 months before the tetraplegic person can expect to use The Freehand System completely in daily life. The tetraplegic individual can choose between two grasps. The Freehand System can for some few very physically disabled tetraplegics be a good aid to increase their level of activities of daily living and independence. Continued development in the coming years may broaden the indications with benefit for more individuals.

In this paper we report a 48-year-old man with septic arthritis of the wrist and ankle due to Streptococcus pneumoniae. No known predisposing factor was found. Only about 300 cases of pneumococcal arthritis have been reported in the literature since 1888 and less than 10% of these affect the wrist. The management of bacterial arthritis is reviewed.

Purpose: To determine whether a "true" neutral lateral view of the wrist is necessary for accurate capitolunate angle measurement, to compare two standards of diagnostic adequacy for neutral lateral wrist views (distal radioulnar overlap [RUO] and scaphopisocapitate [SPC] relationship), and to confirm positional reproducibility and measurement precision of the SPC criterion., Materials and Methods: Capitolunate angles were measured on neutral lateral and supine pisotriquetral views of 10 normal wrists. Two hundred neutral lateral wrist views were classified by each standard (RUO and SPC) as excellent, acceptable, or unacceptable. In two subgroups, capitolunate angles were measured on the lateral views to determine SPC practicality and sensitivity., Results: Compared with neutral lateral positioning, supinated off-lateral views showed an apparent increase in lunate dorsiflexion of up to 30 degrees. Diagnostically unacceptable, excellent, and acceptable pronosupination was present on 118, 22, and 60 of 200 views by using the RUO criterion and on 40, 79, and 81 of 200 views by using the SPC criterion, respectively. The capitolunate angle did not show a significant difference between each of the two subgroups (P > .05)., Conclusion: A true neutral lateral view of the wrist is necessary for accurate measurement of the capitolunate angle on the basis of a comparison with off-lateral views. SPC relationship provides a diagnostically reproducible standard for a neutral lateral wrist view and should reduce the need for repeat lateral radiographs.

The purposes of this study were to determine the rate of infection associated with elective outpatient operations on an extremity, performed in a double-occupancy operating room (one operating room designed to accommodate two separate operating teams), and to determine which factors influenced this rate. We evaluated the records of 2458 consecutive patients who had had such a procedure, performed by one of nine surgeons during a two and one-half-year period, and in whom the operative wound had been classified as clean (without a drain) or clean-contaminated (with a drain). The information regarding the factors associated with the operation and the operating-room environment was recorded for each patient at the time of the operation. Each wound was inspected periodically in the attending surgeon's office for at least thirty days postoperatively. Using definitions established by the Centers for Disease Control, the attending surgeon determined the presence of infection primarily by judging whether there was purulent drainage or whether erythema or swelling at the operative site was beyond that expected from the procedure. Of the 2458 patients, thirty-seven (1.5 per cent; 95 per cent confidence interval, 1.1 to 2.1 per cent) had infection of the operative wound. Only eight patients (0.3 per cent) had deep infection, with seven of the infections necessitating a reoperation. Infection developed in thirty of the 2311 clean wounds, a rate of 1.3 per cent (95 per cent confidence interval, 0.9 to 1.8 per cent), and in seven of the 147 clean-contaminated wounds, a rate of 4.8 per cent (95 per cent confidence interval, 2.3 to 9.5 per cent) (p = 0.001). No cross-contamination occurred between patients who had infection. The rate of infection was not related to the number of patients who were operated on in the same room at the same time. Logistic regression analysis, used to account for confounding factors, demonstrated a significant association between the classification of the wound (use of a drain) and a higher rate of infection (p = 0.006) as well as between the instillation of a topical steroid solution and a lower rate of infection (p = 0.04). It also demonstrated a significant difference, with respect to the rate of infection, among individual surgeons (p = 0.02).