Paal Aksel Naess

Prevalence, predictors and outcome of hypofibrinogenaemia in trauma: a multicentre observational study

IntroductionExsanguination due to trauma-induced coagulopathy is a continuing challenge in emergency trauma care. Fibrinogen is a crucial factor for haemostatic competence, and may be the factor that reaches critically low levels first. Early fibrinogen substitution is advocated by a number of authors. Little evidence exists regarding the indications for fibrinogen supplementation in the acute phase. This study aims to estimate the prevalence of hypofibrinogenaemia in a multi-center trauma population, and to explore how initial fibrinogen concentration relates to outcome. Also, factors contributing to low fibrinogen levels are identified.MethodsPatients arriving in hospital less than 180 minutes post-injury requiring full trauma team activation in four different centers were included in the study. Time from injury, patient demographics, injury severity scores (ISS) and 28 days outcome status were recorded. Initial blood samples for coagulation and blood gas were analyzed. Generalized additive regression, piecewise linear regression, and multiple linear regression models were used for data analyses.ResultsOut of 1,133 patients we identified a fibrinogen concentration ≤1.5g/L in 8.2%, and <2 g/L in 19.2%. A non-linear relationship between fibrinogen concentration and mortality was detected in the generalized additive and piecewise linear regression models. In the piecewise linear regression model we identified a breakpoint for optimal fibrinogen concentration at 2.29 g/L (95% confidence interval (CI): 1.93 to 2.64). Below this value the odds of death by 28 days was reduced by a factor of 0.08 (95% CI: 0.03 to 0.20) for every unit increase in fibrinogen concentration. Low age, male gender, lengthened time from injury, low base excess and high ISS were unique contributors to low fibrinogen concentrations on arrival.ConclusionsHypofibrinogenaemia is common in trauma and strongly associated with poor outcome. Below an estimated critical fibrinogen concentration value of 2.29 g/L a dramatic increase in mortality was detected. This finding indicates that the negative impact of low fibrinogen concentrations may have been previously underestimated. A number of clinically identifiable factors are associated with hypofibrinogenaemia. They should be considered in the management of massively bleeding patients. Interventional trials with fibrinogen substitution in high-risk patients need to be undertaken.

Lipoblastoma: MRI appearances of a rare paediatric soft tissue tumour

Abstract Lipoblastoma is a rare, benign soft-tissue tumour derived from embryonic fat. Four patients with tumours located in the upper limb are reported, with special reference to imaging techniques and histology. Radical surgical excision is essential to prevent local recurrence and exact imaging techniques are thus crucial. MRI appears to be a reliable preoperative investigation and is the recommended radiological examination. In a child under 3 months of age, images showing a predominantly fatty but inhomogeneous soft-tissue mass are suggestive of lipoblastoma.

Simultaneous active compression-decompression and abdominal binding increase carotid blood flow additively during cardiopulmonary resuscitation (CPR) in pigs

The effects of adding active compression-decompression and abdominal binding separately or combined to standard compression CPR was tested in a randomized cross-over design during ventricular fibrillation in eight pigs. The flow and pressure effects of the two techniques appeared to be additive with no interference between the two. Carotid blood flow increased 22% with active compression-decompression, 34% with abdominal binding and 59% with the combination compared to flow with standard compression. Peak antegrade carotid flow occurred in early systole with retrograde flow in early diastole and close to zero in late diastole with no profound alterations induced by active decompression or abdominal binding. Abdominal binding increased the intrathoracic pressure during the compression phase as estimated from the esophageal pressure, while active decompression caused a negative esophageal pressure during the decompression phase. Neither active decompression nor abdominal binding caused any changes in the coronary perfusion pressure, nor in the left ventricular transmural pressure except for a rise in mid-diastolic pressure with active decompression.

Evaluation of TEG® and RoTEM® inter-changeability in trauma patients

BACKGROUND Massive haemorrhage is a leading cause of preventable deaths in trauma. Traumatic coagulopathy is frequently present early after trauma, and is associated with increased mortality. A number of recent trials suggest that viscoelastic haemostatic assays (VHA), such as thromboelastography and thromboelastometry, are useful tools in guiding transfusion. Treatment algorithms exist for the use of VHAs but are not validated in traumatic haemorrhage. In this study we examined the inter-changeability of two commonly used VHAs, TEG(®) and RoTEM(®). METHODS A total of 184 trauma patients over the age of 18, requiring full trauma team activation, were included at three different hospitals in three different countries (Copenhagen, Denmark, San Francisco, CA, USA and Oslo, Norway). Blood samples were drawn immediately upon arrival, and TEG(®) and RoTEM(®) analyzed simultaneously. Correlations were calculated using. Spearmans rank correlation coefficient. Agreement was evaluated by Bland-Altman plots and calculation of limits of agreement. RESULTS The mean ISS in the total population was 17, and the mortality was 16.5%. Mean base excess was -2.8 (SD: 4.2). The correlation coefficient for corresponding values for the two devices was 0.24 for the R-time vs CT in all centres combined. For the K-time vs CFT the correlation was 0.48, for the α-angleTEG vs α-angleRoTEM 0.44, and for MA vs MCF 0.76. Limits of agreement exceeded the preset clinically acceptable deviation of 10% for all variables in all centres except for MA/MCF in one centre (Copenhagen). Generally, correlation coefficients were lower and agreement poorer in the one centre (Oslo) where measurements were performed bedside by clinicians. CONCLUSION Inter-changeability between TEG(®) and RoTEM(®) is limited in the trauma setting. Agreement seems poorer when clinicians operate the devices. Development and validation of separate treatment algorithms for the two devices is required.

Ultrasound performed by radiologists-confirming the truth about FAST in trauma.

BACKGROUND For hemodynamically stable patients with suspected abdominal injuries, the diagnostic accuracy of computed tomographic scans remains unmatched. Focused assessment with sonography for trauma (FAST) is useful in trauma evaluation to identify intraabdominal fluid early in the unstable patient. In skilled hands, sensitivity is shown to be close to 100%. However, some recent studies have questioned its sensitivity in subgroups at risk of bleeding. In most studies, hemodynamic markers of instability have been limited to hypotension. The purpose of this study was to determine the sensitivity and specificity of initial FAST for detection of hemoperitoneum in the potentially unstable patient as judged by objective hemodynamic parameters available early during resuscitation. METHODS Prospective observational study at a major European trauma center. FAST was performed in trauma patients by the trauma team radiologist. The study population consisted of the subgroup deemed potentially unstable on arrival as defined by systolic blood pressure < or =90 mm Hg, pulse rate > or =120, or base deficit > or =8. Results were compared with one of the following reference standards: computed tomographic scan, diagnostic peritoneal lavage, exploratory laparotomy, or observation. RESULTS One hundred and four patients constituted the study group. There were 75 true-negative, 10 false-negative, 16 true-positive, and 3 false-positive FAST results. Sensitivity and specificity were 62% and 96%, positive and negative predictive values 84% and 89%, respectively, and overall accuracy was 88%. CONCLUSION A negative initial FAST in hemodynamically unstable patients, even in the hands of radiologists, cannot reliably exclude intraabdominal bleeding. These patients should undergo additional diagnostic tests to exclude intraperitoneal hemorrhage.

Refining the role of splenic angiographic embolization in high-grade splenic injuries.

BACKGROUND The justification and safety of splenic angiographic embolization (SAE) as an adjunct to nonoperative management (NOM) in high-grade splenic injuries are matters of controversy. At Oslo University Hospital-Ulleval, mandatory SAE was introduced in hemodynamically stable Organ Injury Scale (OIS) Grades 3 to 5 injuries in 2002. From October 2008, mandatory SAE was restricted to OIS Grade 4 injuries or higher. The aim of the present study was to evaluate clinical outcome in patients with high-grade splenic injuries and further define the role of SAE. METHODS All patients 17 years or older with splenic injury admitted from August 1, 2002, to July 31, 2010, were included. Patient charts, computed tomographic scans, and trauma registry data were reviewed. The OIS Grade 3 protocol was amended on October 1, 2008. RESULTS A total of 296 patients with splenic injuries (mean splenic OIS grade, 3.0) resulted in a 70% attempted NOM rate, with 96% success rate. NOM was attempted in 64 (70%) of 91 patients with Grades 4 and 5 injuries, with a 95% success rate. Comparing OIS Grade 3 injuries admitted before (n = 81) and after (n = 35) October 2008, we found similar admission physiology and Injury Severity Score (ISS). Despite the reduction in SAE rate (from 49% to 26%), the NOM rate remained unchanged, as did NOM failure rate (3% vs. 4%), rate of rebleeding, complications, and mortality. CONCLUSION A protocol with mandatory SAE in OIS Grades 4 and 5 injuries resulted in an overall 95% success rate among the 70% eligible for NOM. In OIS Grade 3 splenic injuries, mandatory SAE does not seem justified. LEVEL OF EVIDENCE Therapeutic study, level IV.

The twin terrorist attacks in Norway on July 22, 2011: The trauma center response

BACKGROUND The terrorist attacks in Norway on July 22, 2011, consisted of a bomb explosion in central Oslo, followed by a shooting spree in a youth camp. We describe the trauma center response, identifying possible success factors and suggesting improvements for institutional major incident plans. METHODS The in-hospital response is analyzed. Data on triage, patient flow, injuries, treatment, resources, and outcome were collected. RESULTS The explosion caused a total of 98 casualties and 8 died at scene. Ten patients were triaged to the trauma center, with the first patient arriving 18 minutes after the explosion and 7 patients within the next 19 minutes. The shooting caused 68 deaths at the scene and 61 injured. The trauma center received a total of 21 patients from the shooting incident. Surgical leadership was divided between emergency department triage with control of personnel and communication as well as control and supervision of treatment with retriage and optimal use of trauma surgical resources (dual command). Surge capacity was never exceeded in the emergency department, operating rooms, or intensive care units. Of the 31 patients treated at the trauma center, 20 had an Injury Severity Score of more than 15 and 25 required repeated operation, for a total of 125 operations during the first 4 weeks. One patient died, for a critical mortality of 5%. CONCLUSION A trauma center can handle many patients with severe injury, with low critical mortality when protected from a large number of walking wounded. Limited specific trauma surgical competence was managed by the adoption of a dual surgical command model. LEVEL OF EVIDENCE Therapeutic/care management study, level V.

Non‐operative management and immune function after splenic injury

There is still considerable controversy about the importance and method of preserving splenic function after trauma. Recognition of the immune function of the spleen and the risk of overwhelming postsplenectomy infection led to the development of spleen‐preserving surgery and non‐operative management. More recently angiographic embolization has been used to try to reduce failure of conservative management and preserve splenic function.

Long-Lasting Performance Improvement After Formalization of a Dedicated Trauma Service

BACKGROUND Few studies have evaluated intrainstitutional improvement of trauma care. We hypothesized that the formalization of a dedicated multidisciplinary trauma service in a major Scandinavian trauma center in 2005 would result in improved outcome. METHODS Institutional trauma registry data for 7,243 consecutive patients from the years 2002-2008 were retrospectively evaluated using variable life-adjusted display (VLAD) as one of several performance indicators. VLAD is a refinement of the cumulative sum method that adjusts death and survival by each patients risk status (probability of survival) and provides a graphical display of performance over time. Probability of survival was calculated according to Trauma and Injury Severity Score (TRISS) methodology with National Trauma Data Bank 2005 coefficients. RESULTS VLAD demonstrated a sharp increase in cumulative survival starting at the beginning of 2005 and continuing linearly throughout the study period, amounting to 68 additional saved lives. The increase was mainly caused by improved survival among the critically injured (injury severity score 25-75). A cutoff point t0 for analysis of differences between time periods was set at January 1, 2005, coinciding with the formalization of a dedicated trauma service. Mortality in the whole trauma population showed a 33% decrease after t0. W-statistics confirmed the increased survival to be significant. There were no significant changes in age, gender, or injury mechanism. Injury severity score decreased, but differences in case mix were adjusted for in the survival prediction model. CONCLUSION We have shown that the start of the long-lasting performance improvement coincided with formalization of a dedicated trauma service, providing increased multidisciplinary focus on all aspects of trauma care.

Comparison of the predictive performance of the BIG, TRISS and PS09 score in an adult trauma population derived from multiple international trauma registries

BackgroundThe BIG score (Admission base deficit (B), International normalized ratio (I), andGlasgow Coma Scale (G)) has been shown to predict mortality on admission inpediatric trauma patients. The objective of this study was to assess itsperformance in predicting mortality in an adult trauma population, and to compareit with the existing Trauma and Injury Severity Score (TRISS) and probability ofsurvival (PS09) score.Materials and methodsA retrospective analysis using data collected between 2005 and 2010 from seventrauma centers and registries in Europe and the United States of America wasperformed. We compared the BIG score with TRISS and PS09 scores in a population ofblunt and penetrating trauma patients. We then assessed the discrimination abilityof all scores via receiver operating characteristic (ROC) curves and compared theexpected mortality rate (precision) of all scores with the observed mortalityrate.ResultsIn total, 12,206 datasets were retrieved to validate the BIG score. The mean ISSwas 15 ± 11, and the mean 30-day mortality rate was 4.8%. With an AUROC of0.892 (95% confidence interval (CI): 0.879 to 0.906), the BIG score performed wellin an adult population. TRISS had an area under ROC (AUROC) of 0.922 (0.913 to0.932) and the PS09 score of 0.825 (0.915 to 0.934). On a penetrating-traumapopulation, the BIG score had an AUROC result of 0.920 (0.898 to 0.942) comparedwith the PS09 score (AUROC of 0.921; 0.902 to 0.939) and TRISS (0.929; 0.912 to0.947).ConclusionsThe BIG score is a good predictor of mortality in the adult trauma population. Itperformed well compared with TRISS and the PS09 score, although it hassignificantly less discriminative ability. In a penetrating-trauma population, theBIG score performed better than in a population with blunt trauma. The BIG scorehas the advantage of being available shortly after admission and may be used topredict clinical prognosis or as a research tool to risk stratify trauma patientsinto clinical trials.