Impairment of Mesenteric Perfusion as a Marker of Major Bleeding in Trauma Patients

The majority of potentially preventable mortality in trauma patients is related to bleeding; therefore, early recognition and effective treatment of hemorrhagic shock impose a cardinal challenge for trauma teams worldwide. The reduction in mesenteric perfusion (MP) is among the first compensatory responses to blood loss; however, there is no adequate tool for splanchnic hemodynamic monitoring in emergency patient care. In this narrative review, (i) methods based on flowmetry, CT imaging, video microscopy (VM), measurement of laboratory markers, spectroscopy, and tissue capnometry were critically analyzed with respect to their accessibility, and applicability, sensitivity, and specificity. (ii) Then, we demonstrated that derangement of MP is a promising diagnostic indicator of blood loss. (iii) Finally, we discussed a new diagnostic method for the evaluation of hemorrhage based on exhaled methane (CH₄) measurement. Conclusions: Monitoring the MP is a feasible option for the evaluation of blood loss. There are a wide range of experimentally used methodologies; however, due to their practical limitations, only a fraction of them could be integrated into routine emergency trauma care. According to our comprehensive review, breath analysis, including exhaled CH₄ measurement, would provide the possibility for continuous, non-invasive monitoring of blood loss.

Directed flow of charged particles at midrapidity relative to the spectator plane in Pb-Pb collisions at √(s(NN))=2.76 TeV

The directed flow of charged particles at midrapidity is measured in Pb-Pb collisions at √(s(NN))=2.76 TeV relative to the collision symmetry plane defined by the spectator nucleons. A negative slope of the rapidity-odd directed flow component with approximately 3 times smaller magnitude than found at the highest RHIC energy is observed. This suggests a smaller longitudinal tilt of the initial system and disfavors the strong fireball rotation predicted for the LHC energies. The rapidity-even directed flow component is measured for the first time with spectators and found to be independent of pseudorapidity with a sign change at transverse momenta p(T) between 1.2 and 1.7  GeV/c. Combined with the observation of a vanishing rapidity-even p(T) shift along the spectator deflection this is strong evidence for dipolelike initial density fluctuations in the overlap zone of the nuclei. Similar trends in the rapidity-even directed flow and the estimate from two-particle correlations at midrapidity, which is larger by about a factor of 40, indicate a weak correlation between fluctuating participant and spectator symmetry planes. These observations open new possibilities for investigation of the initial conditions in heavy-ion collisions with spectator nucleons.

K(S)0 and Λ production in Pb-Pb collisions at √(s(NN))=2.76 TeV

The ALICE measurement of K(S)(0) and Λ production at midrapidity in Pb-Pb collisions at √(s(NN))=2.76 TeV is presented. The transverse momentum (p(T)) spectra are shown for several collision centrality intervals and in the p(T) range from 0.4 GeV/c (0.6 GeV/c for Λ) to 12 GeV/c. The p(T) dependence of the Λ/K(S)(0) ratios exhibits maxima in the vicinity of 3 GeV/c, and the positions of the maxima shift towards higher p(T) with increasing collision centrality. The magnitude of these maxima increases by almost a factor of three between most peripheral and most central Pb-Pb collisions. This baryon excess at intermediate p(T) is not observed in pp interactions at √s=0.9 TeV and at √s=7 TeV. Qualitatively, the baryon enhancement in heavy-ion collisions is expected from radial flow. However, the measured p(T) spectra above 2 GeV/c progressively decouple from hydrodynamical-model calculations. For higher values of p(T), models that incorporate the influence of the medium on the fragmentation and hadronization processes describe qualitatively the p(T) dependence of the Λ/K(S)(0) ratio.

Transverse momentum distribution and nuclear modification factor of charged particles in p+Pb collisions at sqrt[s(NN)] = 5.02 TeV

The transverse momentum (p(T)) distribution of primary charged particles is measured in minimum bias (non-single-diffractive) p+Pb collisions at sqrt[s(NN)]=5.02 TeV with the ALICE detector at the LHC. The p(T) spectra measured near central rapidity in the range 0.5<p(T) <20 GeV/c exhibit a weak pseudorapidity dependence. The nuclear modification factor R(pPb) is consistent with unity for p(T) above 2 GeV/c. This measurement indicates that the strong suppression of hadron production at high p(T) observed in Pb+Pb collisions at the LHC is not due to an initial-state effect. The measurement is compared to theoretical calculations.

Pseudorapidity density of charged particles in p+Pb collisions at √(s(NN))=5.02 TeV

The charged-particle pseudorapidity density measured over four units of pseudorapidity in nonsingle-diffractive p+Pb collisions at a center-of-mass energy per nucleon pair √(s(NN))=5.02 TeV is presented. The average value at midrapidity is measured to be 16.81±0.71 (syst), which corresponds to 2.14±0.17 (syst) per participating nucleon, calculated with the Glauber model. This is 16% lower than in nonsingle-diffractive pp collisions interpolated to the same collision energy and 84% higher than in d+Au collisions at s√(s(NN))=0.2 TeV. The measured pseudorapidity density in p+Pb collisions is compared to model predictions and provides new constraints on the description of particle production in high-energy nuclear collisions.

Charge separation relative to the reaction plane in Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV

Measurements of charge-dependent azimuthal correlations with the ALICE detector at the LHC are reported for Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV. Two- and three-particle charge-dependent azimuthal correlations in the pseudorapidity range |η| < 0.8 are presented as a function of the collision centrality, particle separation in pseudorapidity, and transverse momentum. A clear signal compatible with a charge-dependent separation relative to the reaction plane is observed, which shows little or no collision energy dependence when compared to measurements at RHIC energies. This provides a new insight for understanding the nature of the charge-dependent azimuthal correlations observed at RHIC and LHC energies.

Pion, kaon, and proton production in central Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV

In this Letter we report the first results on π(±), K(±), p, and p production at midrapidity (|y|<0.5) in central Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV, measured by the ALICE experiment at the LHC. The p(T) distributions and yields are compared to previous results at sqrt[s(NN)] = 200 GeV and expectations from hydrodynamic and thermal models. The spectral shapes indicate a strong increase of the radial flow velocity with sqrt[s(NN)], which in hydrodynamic models is expected as a consequence of the increasing particle density. While the K/π ratio is in line with predictions from the thermal model, the p/π ratio is found to be lower by a factor of about 1.5. This deviation from thermal model expectations is still to be understood.

Measurement of the cross section for electromagnetic dissociation with neutron emission in Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV

The first measurement of neutron emission in electromagnetic dissociation of ^{208}Pb nuclei at the LHC is presented. The measurement is performed using the neutron zero degree calorimeters of the ALICE experiment, which detect neutral particles close to beam rapidity. The measured cross sections of single and mutual electromagnetic dissociation of Pb nuclei at sqrt[s(NN)]=2.76 TeV with neutron emission are σ(singleEMD)=187.4 ± 0.2(stat)(-11.2)(+13.2) (syst) b and σ(mutualEMD) = 5.7 ± 0.1(stat) ± 0.4(syst) b, respectively. The experimental results are compared to the predictions from a relativistic electromagnetic dissociation model.

Production of muons from heavy flavor decays at forward rapidity in pp and Pb-Pb collisions at sqrt[s(NN)]=2.76 TeV

The ALICE Collaboration has measured the inclusive production of muons from heavy-flavor decays at forward rapidity, 2.5<y<4, in pp and Pb-Pb collisions at sqrt[s(NN)]=2.76  TeV. The p(t)-differential inclusive cross section of muons from heavy-flavor decays in pp collisions is compared to perturbative QCD calculations. The nuclear modification factor is studied as a function of p(t) and collision centrality. A weak suppression is measured in peripheral collisions. In the most central collisions, a suppression of a factor of about 3-4 is observed in 6<p(t)<10  GeV/c. The suppression shows no significant p(t) dependence.

J/ψ suppression at forward rapidity in Pb-Pb collisions at √s(NN) = 2.76 TeV

The ALICE experiment has measured the inclusive J/ψ production in Pb-Pb collisions at √s(NN) = 2.76 TeV down to zero transverse momentum in the rapidity range 2.5 < y < 4. A suppression of the inclusive J/ψ yield in Pb-Pb is observed with respect to the one measured in pp collisions scaled by the number of binary nucleon-nucleon collisions. The nuclear modification factor, integrated over the 0%-80% most central collisions, is 0.545 ± 0.032(stat) ± 0.083(syst) and does not exhibit a significant dependence on the collision centrality. These features appear significantly different from measurements at lower collision energies. Models including J/ψ production from charm quarks in a deconfined partonic phase can describe our data.

J/ψ polarization in pp collisions at √s=7 TeV

The ALICE Collaboration has studied J/ψ production in pp collisions at √s=7 TeV at the LHC through its muon pair decay. The polar and azimuthal angle distributions of the decay muons were measured, and results on the J/ψ polarization parameters λ(θ) and λ(φ) were obtained. The study was performed in the kinematic region 2.5<y<4, 2<p(t)<8 GeV/c, in the helicity and Collins-Soper reference frames. In both frames, the polarization parameters are compatible with zero, within uncertainties.

Centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV

The centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s_{NN}]=2.76  TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of 2 from peripheral (70%-80%) to central (0%-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.

Elliptic flow of charged particles in Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at sqrt[S(NN)] =2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2<p t<5.0 GeV/c. The elliptic flow signal v₂, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ± 0.002(stat) ± 0.003(syst) in the 40%-50% centrality class. The differential elliptic flow v₂ p t reaches a maximum of 0.2 near p t =3 GeV/c. Compared to RHIC Au-Au collisions at sqrt[S(NN)] 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.

Charged-particle multiplicity density at midrapidity in central Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

The first measurement of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at a center-of-mass energy per nucleon pair √ S NN = 2.76 TeV is presented. For an event sample corresponding to the most central 5% of the hadronic cross section, the pseudorapidity density of primary charged particles at midrapidity is 1584 ± 4(stat) ± 76(syst), which corresponds to 8.3 ± 0.4(syst) per participating nucleon pair. This represents an increase of about a factor 1.9 relative to pp collisions at similar collision energies, and about a factor 2.2 to central Au-Au collisions at √ S NN = 2.76 TeV. This measurement provides the first experimental constraint for models of nucleus-nucleus collisions at LHC energies.

Midrapidity antiproton-to-proton ratio in pp collisons at sqrt[s]=0.9 and 7 TeV measured by the ALICE experiment

The ratio of the yields of antiprotons to protons in pp collisions has been measured by the ALICE experiment at sqrt[s]=0.9 and 7 TeV during the initial running periods of the Large Hadron Collider. The measurement covers the transverse momentum interval 0.45<p_{t}<1.05  GeV/c and rapidity |y|<0.5. The ratio is measured to be R_{|y|<0.5}=0.957±0.006(stat)±0.014(syst) at 0.9 TeV and R_{|y|<0.5}=0.991±0.005(stat)±0.014(syst) at 7 TeV and it is independent of both rapidity and transverse momentum. The results are consistent with the conventional model of baryon-number transport and set stringent limits on any additional contributions to baryon-number transfer over very large rapidity intervals in pp collisions.

[Spontaneous "regeneration" of the spinal canal in traumatic bone fragments after fractures of the thoraco-lumbar transition and the lumbar spine]

This is a report about four patients in whom spontaneous remodelling of the spinal canal was observed after thoracolumbar fractures with intraspinal bone fragments leading to narrowing by 33-93%. One of the patients was female and three male; two patients had partial neurologic deficits and two had none. The ages of the patients were 33, 16, 65 and 16 years, and the fractures were localized in one case in segment T-12 in two in L-1 and in one in L-4. Active functional treatment was performed with no repositioning or plastering. The changes in spinal canal narrowing and the bone union were monitored by means of CT scans. The follow-up is 9-27 months. The intraspinal bone fragments gradually disappeared in all cases, while the partial neurologic deficits regressed. All patients are now free of troublesome complaints. We would therefore like to point out that thoracolumbar fractures without complete neurologic deficit that are associated with intraspinal bone fragments, whatever their size, should not immediately be treated by surgery, because conservative active functional treatment with spontaneous remodelling of the spinal canal gives results as good as those of operative treatment with far less risk.

Arterial pseudoaneurysm of the ankle after plantar flexion-inversion injury. A rare complication and its non-invasive diagnosis

We report a case of arterial pseudoaneurysm over the lateral side of the ankle caused by plantar flexion-inversion injury and discuss the aetiology of this rarely seen complication. In the English orthopaedic literature, our case is the first of the very few previously reported cases with a similar aetiology which was examined and confirmed by colour Doppler ultrasound.

[Acute venous liver circulatory disorder caused by blunt abdominal trauma: is it a compartment syndrome?]

Authors describe the case of a 37-year-old female patient who had been operated on for a subcapsular haematoma of the liver that had developed following a blunt abdominal trauma. This manifested as a Budd-Chiari syndrome-like phenomenon that was not recognized until an exploratory operation was performed, when we found that the liver was hard and dark purple in colour and there was considerable ascites in the abdominal cavity. After aspiration of the haematoma, which contained about 1 l of a mixture of fluid and clotted blood, the circulation of the liver rapidly improved. On the basis of the findings, a posttraumatic Budd-Chiari syndrome seems unlikely, since the symptoms caused by the rise in intracapsular pressure are similar to those of a compartment syndrome. No literature data can be found to define such a posttraumatic failure of the liver circulation. Subcapsular and intrahepatic haematomata can be successfully monitored by ultrasonography and managed conservatively if they are asymptomatic. Operation is restricted to lesions with worsening symptoms or increasing danger of haemorrhage.

[The LS-8 lever fixator: repositioning and fixation aids for dislocations and dislocation fractures of the lumbar spine and the thoracolumbar transition. Part I. Biomechanical considerations and surgical technique]

We are reporting a lever-type internal fixateur, the LS-8 system, which can be used for reduction and stable fixation of fractures and fracture-dislocations of the thoraco-lumbar and lumbar spine. The LS-8 system is different from all previous systems: it combines the advantages of the spinal fixateur interne and conventional plate fixation, while largely avoiding their disadvantages, such as the fixed position of the screw hole and the mechanical overloading of the fixing points, as in the previous hook-type systems. In order to minimize these drawbacks, we have added a plate of variable length to our system, creating a fulcrum that prevents overloading. This means that the reinforced 8 mm diameter screws function as lever arms around this fulcrum, conducting and counterbalancing the active forces. As a result, the loading capacity of our system has been greatly improved. Since the LS-8 "lever fixateur" is a reinforced system, it is no longer necessary to use any plaster or brace fixation. We should like to illustrate the advantages and the capability of the LS-8 system by presenting one of our cases.

[Ruptured retroperitoneal bile duct cyst. An extremely rare injury after blunt abdominal trauma]

Management of a retroperitoneal extrahepatic bile duct cystenteric tear at a cystenteric malformation of the intra- and extrahepatic ducts (Todani IV-A) discovered during an emergency surgical procedure following an accident is presented and the problems associated with bile duct cysts are discussed. It is pointed out that acute treatment with a simple and safe method (external Kehr-T drainage) can be successful when injuries are present, although most trauma surgeon are seldom, and many never, directly confronted with injuries attributable to these extremely rare malformations.

[Use of the "pronation worm" in the early functional active-conservative treatment of lateral ligamentous rupture of the ankle]

The "pronation worm", a method of early functional active conservative treatment for sprained ankle, is presented. In our department 75 patients were treated with this method with great success. Recent lateral tears in the ankle were confirmed by stress X-ray examinations, and according to these the patients were divided into two groups: group 1, containing patients with opening of the joint gap to 10-14 degrees (one-ligament injuries); and group 2, containing those with opening to 15 degrees or more (more-ligament injuries). The patients were required to wear ankle boots with a "pronation worm" for 6 weeks though they could take them off to get bathed, clean the boots and at bedtime. They were also asked to perform muscle training exercises for the peroneus muscles three times a day. The clinical-radiological evaluation showed complete healing in 97.3% after 6 weeks and after 6 months, and the stress X-ray photographs confirmed that there was no pathological opening of the joint gap (this applies to all patients in group 1 and 46 in group 2). In two patients in group 2 (2.7%) the X-ray pictures revealed pathologic opening of the joint-gap, but these patients had no subjective symptoms. These preliminary results suggest that recent tears of the lateral ligament ankle should be treated with this early functional active conservative method, i.e. without a surgical operation.

[Surgically stabilizing "complex therapy" of unstable injury of the lower cervical spine]

Numerous assessments of the stability of screws within the cervical vertebral bodies after strong mechanical loading showed that spondylodesis can be considered as a stable fixation whether it is performed as a ventral, dorsal of combined procedure. Luxation fractures of the cervical spine, however, often do not only show lesions of the osteo-ligamentary structures, but are also accompanied by lesions of the spinal marrow. In addition to surgical measures, the self-destructing fermentative processes occurring in the mechanically injured spinal marrow have to be and can be eliminated or at least reduced by chemotherapy. The immediate simultaneous chemotherapeutic and surgical treatment is presented as "complex therapy" and recommended because of its good results.