Rotation thromboelastometry detects thrombocytopenia and hypofibrinogenaemia during orthotopic liver transplantation.

BACKGROUND: Orthotopic liver transplantation can be associated with haemorrhage, particularly in patients with severe liver dysfunction. We assessed the value of rotation thromboelastometry (ROTEM) to monitor coagulation in the operating theatre, its correlation with routine laboratory findings, and its ability to guide platelet (Plt) and fibrinogen (Fg) transfusion. METHODS: Twenty-three patients were included in this prospective observational study. Laboratory tests and ROTEM tests (EXTEM, INTEM, FIBTEM, and APTEM) were performed six times during the procedure. Correlations between laboratory findings and ROTEM parameters were sought. Thresholds for ROTEM parameters were determined with receiver-operating characteristic (ROC) curve analysis according to Plt count and Fg levels. RESULTS: Clot amplitude at 10 min (A10) of EXTEM was well correlated with Plt count and Fg levels (R(2)=0.46 and 0.52, respectively, P<0.0001). FIBTEM A10 was correlated with Fg (R(2)=0.55, P<0.0001). ROC analysis showed that EXTEM A10 with a threshold of 29 mm predicted thrombocytopenia with a sensitivity of 79% and a specificity of 60%, and a threshold of 26 mm predicted hypofibrinogenaemia with a sensitivity of 83% and a specificity of 75%. CONCLUSIONS: ROTEM is useful for the global assessment of coagulation in the operating theatre. EXTEM was the most informative for assessing the whole coagulation process and A10 showed value in guiding Plt and Fg transfusion.

Validation of a bedside activated clotting time test (Hemochron Jr II Signature) with low dose heparin therapy.

The purpose of this study was to validate a device designed to measure activated clotting time in low-range heparin plasma concentrations (ACT-LR) prospectively during the post-operative period of vascular surgery. Measurement of ACT-LR and activated partial thromboplastin time (APTT) were performed before heparinisation (T0) and at the end of surgery (T1). ACT-LR(T1) and DeltaACT-LR (defined as ACT-LR(T1) - ACT-LR(T0)) were evaluated as diagnostic tests for excessive anticoagulation, defined by APTT more than twice the laboratory's normal, by Bland-Altman method and receiver operating characteristic (ROC) curves. In 103 patients, mean (SD) ACT-LR was 137 (33) s at T0 and 176 (39) s at T1. Bland-Altman graph did not show a good agreement between APTT and ACT-LR. Areas under ROC curves were 0.82 (95% CI: 0.75-0.89) and 0.87 (95% CI: 0.80-0.93) for ACT-LR(T1) and DeltaACT-LR, respectively. Using a threshold of 32 s for DeltaACT-LR, test sensitivity was 87% (95% CI: 81-93%), specificity was 85% (95% CI: 78-92%), positive predictive value was 90% (95% CI: 84-96%) and negative predictive value was 81% (95% CI: 73-86%). While DeltaACT-LR may have some potential in evaluating excessive anticoagulation in vascular surgery, the poor correlation between ACT-LR and APTT does not support its routine use.

Uncalibrated pulse contour-derived stroke volume variation predicts fluid responsiveness in mechanically ventilated patients undergoing liver transplantation.

BACKGROUND: Stroke volume variation (SVV) is able to predict adequately the individual response to fluid loading. Our objective was to assess whether the SVV measured by a new algorithm (Vigileo; Flotrac) can predict fluid responsiveness. METHODS: Forty mechanically ventilated patients undergoing liver transplantation, who needed volume expansion (VE), were included. VE was done with albumin (4%) 20 mlxBMI over 20 min. SVV, pulse pressure variation (PPV), central venous pressure (CVP), and pulmonary artery occlusion pressure (PAOP) were measured immediately before and after VE. Cardiac output (CO) measured by transthoracic echocardiography (CO-TTE) was used to define responder patients if CO increased by 15% or more after VE, or non-responder otherwise. CO obtained with the pulmonary artery catheter (CO-PAC) and with Vigileo (CO-Vigileo) were also recorded. RESULTS: Five patients were excluded. Seventeen patients were responders (Rs) and 18 were non-responders (NRs). Before VE (i) SVV and PPV were higher in Rs and (ii) CVP and PAOP were lower in Rs. Baseline SVV and PPV correlated with change in CO induced by VE (respectively, r(2)=0.72, P<0.0001; r(2)=0.84, P<0.0001). An SVV threshold of >10% discriminated Rs with a sensitivity of 94% and a specificity of 94%. After VE, the decrease in SVV was significantly correlated with the increase in CO (r(2)=0.51; P<0.0001). There was no difference between the area under the ROC curves of SVV and PPV. After VE, the change in CO-Vigileo was closely correlated with change in CO-TTE (r(2)=0.74, P<0.0001) and with change in CO-PAC (r(2)=0.77, P<0.0001). CONCLUSIONS: The SVV obtained by the Vigileo system may be used as a predictor of fluid responsiveness in patients with circulatory failure after liver transplantation. CO-Vigileo is able to track the change in CO induced by VE.

[Heat stroke and fulminans hepatitis: is MARS system relevant?]. / Coup de chaleur d'exercice avec hépatite fulminante: intérêt du système MARS?

Exertional heat stroke (EHS) is a life-threatening condition caused by an extreme elevation in core body temperature. Acute liver failure has been reported during EHS justifying liver transplantation in some cases. The Molecular Adsorbent Recirculating System (MARS) could be indicated in such situations. We report a case of a 58-year old patient who suffered acute liver failure occurring after EHS. The patient was referred for liver transplantation and benefited of MARS therapy. After three sessions of MARS, liver function improved progressively and the transplantation was not necessary. The patient completely recovered.

An ex vivo original test using radiotracers for evaluating haemocompatibility of tubular biomaterials.

The haemocompatibility of a vascular prosthesis can be estimated as the result of its interaction with blood components. The authors describe an ex vivo canine shunt for evaluating isotopic haemocompatibility in blood-wall interactions. Methods employing radioisotopic tracers can be used to dynamically monitor the adsorption of labelled blood cells and proteins on different biomaterial surfaces. This ex vivo test should enable materials to be assessed for quality according to two thrombogenic criteria: (i) number of adhered platelets mm-2 s-1; (ii) quantity of adsorbed fibrinogen expressed as microgram mm-2 s-1, which would provide the basis for a scale of haemocompatibility.

[Target-controlled infusion of propofol for intraoperative sedation: determination of effect-site concentration and assessment of bispectral index]. / Sédation peropératoire à objectif de concentration avec le propofol: détermination des concentrations au site d'action et évaluation de l'index bispectral.

OBJECTIVES: To determine the effect-site concentration (Ce) of propofol, required to achieving adequate sedation. To assess the efficacy and safety of a target-controlled infusion system during monitored anaesthesia care and to evaluate the ability of bispectral index (BIS) to predict sedation level. Study design. - Prospective clinical study. PATIENTS: Women scheduled for insertion of tension-free vaginal tape under local anaesthetic infiltration. METHODS: After premedication with hydroxyzine, 1% propofol was infused using the Diprifusor system at an initial target plasma concentration (Cc) of 1 microg/ml and then adjusted by steps of 0.2 microg/ml at 5 min intervals. The level of sedation was assessed using the observer's assessment of alertness/sedation (OAA/S) scale; the objective was to obtain an OAA/S level at 4 or 3 (response to verbal stimulation). Ce of propofol and BIS were noted every 5 min. Relation between Ce or BIS and OAA/S scale was analysed by linear regression and probability of prediction (P(K)). RESULTS: Fifty patients aged 62 +/- 12 years were studied. Sedation at level 4 or 3 was observed in all patients. Ce of propofol and BIS to maintain this OAA/S score were, respectively, 1.0 +/- 0.2 microg/ml and 87 +/- 7. There was a linear relation between OAA/S scale and BIS or Ce; however, individual values demonstrate wide variability. The average of P(K) values computed for each patient for the BIS and Ce was 0.84 and 0.83, respectively. CONCLUSIONS: Target-controlled infusion of propofol provides easy and safe management of intraoperative sedation, allowing a fast and precise adjustment of the propofol concentration to the clinical response of the patient.

[Severe acute hepatic failure and haemophagocytic syndrome: cause or consequence?]. / Insuffisance hépatique aiguë sévère et syndrome d'activation macrophagique: cause ou conséquence?

Haemophagocytic syndrome corresponds to an unconnected macrophagic activity with haemophagocytosis. We report the case of a haemophagocytic syndrome in a 49-year-old woman with initially a severe acute hepatic failure. This syndrome is probably underestimated in ICU patients. Haemophagocytic syndrome should be suspected in patients with fever and jaundice without infection.

[Coronary artery dissection complicated by myocardial infarction in a head trauma patient]. / Dissection coronaire traumatique compliquée d'infarctus du myocarde chez un patient traumatisé crânien.

Acute myocardial infarction, following coronary artery dissection, is a rare, but potentially fatal, syndrome after blunt chest trauma. The treatment is more complicated when intracerebral lesions are present, because of the need of anticoagulation. We report the case of a 37-year-old male patient, suffering from a polytraumatism with intracranial petechial haemorrhages who have a left coronary artery dissection with acute myocardial infarction.

Risk factors for bleeding and transfusion during orthotopic liver transplantation.

OBJECTIVE: While orthotopic liver transplantation (OLT) can be associated with haemorrhage, the risk factors for bleeding and transfusion remain difficult to predict. Perioperative transfusion has potentially deleterious side effects and impairs graft and patient survival. Preoperative identification of patients at high risk of bleeding is of clinical interest to manage perioperative transfusion and blood product storage. STUDY DESIGN: Retrospective study. PATIENTS AND METHODS: All OLT conducted between 2004 and 2008 in the University Hospital of Bordeaux were studied. Risk factors for bleeding greater than one blood volume and for massive red blood cell (RBC) transfusion were determined using univariate and multivariate analysis. Thresholds were determined with ROC curve analysis. RESULTS: One hundred and forty-eight transplantations were studied. Preoperative haemoglobin and Child class A were independent protective risk factors for bleeding greater than one blood volume (OR 0.81 [0.67-0.98] and 0.27 [0.10-0.72], respectively). Preoperative Hb was a protective risk factor (OR 0.71 [0.58-0.88]) whereas history of oesophageal varicose bleeding was a risk factor (OR 4.67 [1.45-15.05]) for transfusion of more than eight RBC. CONCLUSION: Risk factors for bleeding and transfusion during OLT identified in this study were of little clinical usefulness so blood products should always be available during the procedure.

Continuous non-invasive arterial pressure measurement: evaluation of CNAP device during vascular surgery.

OBJECTIVE: Standard non-invasive blood pressure (BP) monitoring is an intermittent, discontinuous procedure. Beat-to-beat BP monitoring requires invasive measurement via an arterial catheter and may be associated with serious complications. The Infinity CNAP SmartPod (Dräger Medical AG & Co. KG, Lübeck, Germany) has recently been proposed for non-invasive continuous beat-to-beat BP measurements. The present study was designed to compare BP obtained with the CNAP and with an invasive method in the operating room. STUDY DESIGN: Prospective study. PATIENTS AND METHODS: Twenty-five patients undergoing major vascular surgery were included. Systolic, mean and diastolic BP were monitored invasively (SAP, MAP and DAP respectively) and not invasively using the CNAP (CNAP-S, CNAP-M and CNAP-D respectively). Measurements were performed intraoperatively every minute during 1 hour. RESULTS: One thousand and five hundred pairs of simultaneous CNAP and invasive BP measurements were obtained and 148 were eliminated. The range of BP measurements was 63-205 mmHg for SAP and 57-187 mmHg for CNAP-S, 38-143 mmHg for MAP and 43-142 mmHg for CNAP-M, 29-126 mmHg for DAP and 33-121 mmHg for CNAP-D. Bias and 95% limit of agreement between CNAP and invasive BP measurements were respectively 7.2 and -17.7 to 32.2 mmHg for SAP, -1.8 and -22.0 to 18.3 mmHg for MAP, and -7.5 and -27.3 to 12.4 mmHg for DAP. The percentage of CNAP measurements with a bias <10% with the arterial line was 69%, 86% and 91% for systolic, diastolic and mean pressures, respectively. CONCLUSION: Despite low accuracy for SAP and DAP measurements, CNAP system seems more accurate for MAP measurement in patients undergoing vascular surgery.

[Iatrogenic gas embolism after the use of hydrogen peroxide]. / Embolie gazeuse iatrogène après utilisation de peroxyde d'hydrogène.

We report a case of severe oxygen embolism after wound irrigation under pressure with hydrogen peroxide into a closed or partially closed cavity. The accident was observed during a surgical dressing of a large pelvis gangrene area, after a 250 ml injection of hydrogen peroxide. Suddenly occurred a decrease in PETCO(2) and SpO(2), and then heart arrhythmia. Symptomatic treatment initiated immediately restored SpO(2) and heart rhythm within a few minutes and the patient was then treated with hyperbaric oxygen therapy. The patient recovered without cardiac or neurologic sequelae. The release of gaseous oxygen under the effect of tissue catalase and the vascular diffusion of this oxygen bubbles can explain such complication. Injection of large volume of hydrogen peroxide into a closed or partially closed cavity and/or under pressure injection must be prohibited.

[Cranial subdural haematoma after spinal anaesthesia treated by blood patch]. / Hématome sous-dural aigu intracrânien après rachianesthésie traité par blood patch.

The authors report a case of subdural haematoma after spinal anaesthesia. A 36-year-old woman underwent phlebectomy under spinal anaesthesia. Two days later, she complains of severe headache without neurological signs, not responding to bed rest and analgesics. Magnetic resonance imaging showed a small acute subdural haematoma in the right parieto-occipital region. On the forth day, she was given a blood-patch, which improved rapidly the patient. Recovery was complete.

Mathematical analysis of the upper respiratory tract from an anthropometric study.

In order to design a new, performed tracheal tube adapted to the shape of the upper respiratory tract, we have undertaken an anthropometric study from lateral x-rays of the neck in 130 patients with the head in a fixed position. In order to assess different clinical situations, we studied three groups of patients: group 1 = sitting, no tracheal tube; group 2 = supine, no tracheal tube; group 3 = supine, trachea intubated. We defined a standard coordinate system and determined mathematical curves for segments of the upper respiratory tract by a polynomial regression method. With these data it was possible to study the effects of physiological variations on the shape of the curves. It was then possible to determine at which region changes occur and the factors influencing these changes. We found that the relative position of the larynx was constant, whereas the hypopharynx exhibited the greatest change with the position of the head. These observations should allow us to construct a new, performed tracheal tube with elastic compliance properties to fit the changes occurring in the region of the hypopharynx.

[Consequences on the nursing team of the information of spinal cord injured patients]. / Conséquences sur l'équipe soignante de l'information des blessés médullaires.

For spine-wounded people, an early information about lesions forecast is as necessary as difficult. At the beginning, patients have'nt still realized their state seriousness, and diagnosis stays uncertain. This retrospective work tries to explore how early information is remembered and the consequences about hospital experience, in intensive care unit and in rehabilitation. It shows that early information does'nt modify this experience, but that relations between nurses and patients become better.