Prognostic significance of central venous-to-arterial carbon dioxide difference during the first 24 hours of septic shock in patients with and without impaired cardiac function.

OBJECTIVE: To investigate the prognostic significance of central venous-to-arterial carbon dioxide difference (cv-art CO 2 gap) during septic shock in patients with and without impaired cardiac function. METHODS: We performed a prospective cohort study in 10 French intensive care units. Patients suffering from septic shock were assigned to the impaired cardiac function group ('cardiac group', n =123) if they had atrial fibrillation (AF) and/or left ventricular ejection fraction (LVEF) <50% at study entry and to the non-cardiac group ( n =240) otherwise. RESULTS: Central venous and arterial blood gases were sampled every 6 h during the first 24 h to calculate cv-art CO 2 gap. Patients in the cardiac group had a higher cv-art CO 2 gap [at study entry and 6 and 12 h (all P <0.02)] than the non-cardiac group. Patients in the cardiac group with a cv-art CO 2 gap >0.9 kPa at 12 h had a higher risk of day 28 mortality (hazard ratio=3.18; P =0.0049). Among the 59 patients in the cardiac group with mean arterial pressure (MAP) ≥65 mm Hg, central venous pressure (CVP) ≥8 mm Hg and central venous oxygen saturation (ScvO 2 ) ≥70% at 12 h, those with a high cv-art CO 2 gap (>0.9 kPa; n =19) had a higher day 28 mortality (37% vs. 13%; P =0.042). In the non-cardiac group, a high cv-art CO 2 gap was not linked to a higher risk of day 28 death, whatever the threshold value of the cv-art CO 2 gap. CONCLUSION: Patients with septic shock and with AF and/or low LVEF were more prone to a persistent high cv-art CO 2 gap, even when initial resuscitation succeeded in normalizing MAP, CVP, and ScvO 2 . In these patients, a persistent high cv-art CO 2 gap at 12 h was significantly associated with higher day 28 mortality.

Predicting arterial blood gas and lactate from central venous blood analysis in critically ill patients: a multicentre, prospective, diagnostic accuracy study.

BACKGROUND: The estimation of arterial blood gas and lactate from central venous blood analysis and pulse oximetry [Formula: see text] readings has not yet been extensively validated. METHODS: In this multicentre, prospective study performed in 590 patients with acute circulatory failure, we measured blood gases and lactate in simultaneous central venous and arterial blood samples at 6 h intervals during the first 24 h after insertion of central venous and arterial catheters. The study population was randomly divided in a 2:1 ratio into model derivation and validation sets. We derived predictive models of arterial pH, carbon dioxide partial pressure, oxygen saturation, and lactate, using clinical characteristics, [Formula: see text], and central venous blood gas values as predictors, and then tested their performance in the validation set. RESULTS: In the validation set, the agreement intervals between predicted and actual values were -0.078/+0.084 units for arterial pH, -1.32/+1.36 kPa for arterial carbon dioxide partial pressure, -5.15/+4.47% for arterial oxygen saturation, and -1.07/+1.05 mmol litre(-1) for arterial lactate (i.e. around two times our predefined clinically tolerable intervals for all variables). This led to ∼5% (or less) of extreme-to-extreme misclassifications, thus giving our predictive models only marginal agreement. Thresholds of predicted variables (as determined from the derivation set) showed high predictive values (consistently >94%), to exclude abnormal arterial values in the validation set. CONCLUSIONS: Using clinical characteristics, [Formula: see text], and central venous blood analysis, we predicted arterial blood gas and lactate values with marginal accuracy in patients with circulatory failure. Further studies are required to establish whether the developed models can be used with acceptable safety.

Systematic review and literature appraisal on methodology of conducting and reporting critical-care echocardiography studies: a report from the European Society of Intensive Care Medicine PRICES expert panel.

BACKGROUND: The echocardiography working group of the European Society of Intensive Care Medicine recognized the need to provide structured guidance for future CCE research methodology and reporting based on a systematic appraisal of the current literature. Here is reported this systematic appraisal. METHODS: We conducted a systematic review, registered on the Prospero database. A total of 43 items of common interest to all echocardiography studies were initially listed by the experts, and other "topic-specific" items were separated into five main categories of interest (left ventricular systolic function, LVSF n = 15, right ventricular function, RVF n = 18, left ventricular diastolic function, LVDF n = 15, fluid management, FM n = 7, and advanced echocardiography techniques, AET n = 17). We evaluated the percentage of items reported per study and the fraction of studies reporting a single item. RESULTS: From January 2000 till December 2017 a total of 209 articles were included after systematic search and screening, 97 for LVSF, 48 for RVF, 51 for LVDF, 36 for FM and 24 for AET. Shock and ARDS were relatively common among LVSF articles (both around 15%) while ARDS comprised 25% of RVF articles. Transthoracic echocardiography was the main echocardiography mode, in 87% of the articles for AET topic, followed by 81% for FM, 78% for LVDF, 70% for LVSF and 63% for RVF. The percentage of items per study as well as the fraction of study reporting an item was low or very low, except for FM. As an illustration, the left ventricular size was only reported by 56% of studies in the LVSF topic, and half studies assessing RVF reported data on pulmonary artery systolic pressure. CONCLUSION: This analysis confirmed sub-optimal reporting of several items listed by an expert panel. The analysis will help the experts in the development of guidelines for CCE study design and reporting.

Role of superantigenic strains in the prognosis of community-acquired methicillin-susceptible Staphylococcus aureus bacteraemia.

Methicillin-susceptible Staphylococcus aureus (MSSA) strains can produce superantigenic toxins that may trigger a massive release of pro-inflammatory cytokines, which are involved in the onset of septic shock. This 1-year prospective pilot study assessed the role of the production of superantigenic toxins in the outcome of immunocompetent patients hospitalised for community-acquired MSSA bacteraemia. Thirty-seven patients were enrolled, of whom 14 died in hospital. Fourteen patients had septic shock, and the mortality rate in this subgroup was 56%. Twenty-seven (73%) isolates produced at least one superantigenic toxin, but this did not influence the rate of occurrence of septic shock or death.

Use of color kinesis for evaluation of left ventricular filling in patients with dilated cardiomyopathy and mitral regurgitation.

OBJECTIVES: We tested the feasibility of using analysis of color kinesis images to objectively assess global and regional left ventricular (LV) diastolic function in patients with dilated cardiomyopathy (DCM). In addition, the ability of this technique to track drug-induced changes on LV diastolic properties was studied. BACKGROUND: Diastolic dysfunction contributes to symptomatology in patients with DCM. The assessment of LV diastolic function using conventional Doppler echocardiography is indirect and is confounded by multiple variables. Moreover, the noninvasive evaluation of regional diastolic properties is difficult. In contrast, color kinesis directly tracks and color-encodes regional diastolic endocardial motion. METHODS: We studied 24 patients with DCM and mitral regurgitation (MR) and 24 age-matched normal subjects. Transmitral and pulmonary vein flow velocities were measured using pulsed Doppler echocardiography. Diastolic color kinesis images were used to calculate indexes of magnitude and timing of global and regional diastolic function. Diastolic asynchrony was evaluated in different subgroups of patients with DCM. The effects of drug infusions (nitroprusside and dobutamine) were also studied. RESULTS: Color kinesis indexes of global diastolic function showed significant differences between patients with DCM and normal subjects. Compared with Doppler indexes, color kinesis was less confounded by MR and was capable of differentiating between drug-induced lusitropic and vasodilator effects. Diastolic asynchrony was increased in patients with DCM and severe MR. CONCLUSIONS: Quantitative analysis of global and regional LV diastolic function in patients with DCM using color kinesis is feasible.

Thrombocytopenia in the sepsis syndrome: role of hemophagocytosis and macrophage colony-stimulating factor.

BACKGROUND: Thrombocytopenia is frequently encountered in critically ill patients with the sepsis syndrome, but its mechanisms frequently remain undetermined. Hemophagocytosis has been reported as a cause of thrombocytopenia in various diseases. This prospective study was designed to assess: (1) the incidence of hemophagocytosis in patients suffering from both the sepsis syndrome and unexplained thrombocytopenia, and (2) the circulating level of the macrophage-colony-stimulating factor (M-CSF) according to the presence or absence of hemophagocytosis. METHODS: Fifty consecutive patients diagnosed with both the sepsis syndrome and thrombocytopenia of undetermined origin were studied. Hemophagocytosis was diagnosed based on microscopical examination of sternal bone marrow aspiration by two independent observers. Serum M-CSF concentrations were measured in each patient and compared with levels of a normal population (n = 59). Causes and severity of sepsis syndromes as well as serum M-CSF levels were compared between patients with and without hemophagocytosis. RESULTS: Hemophagocytosis was diagnosed in 32 patients (64%). Mean serum M-CSF levels were increased in patients when compared with normal subjects (539 +/- 141 versus 208 +/- 82 IU/mL: P < 0.001), and higher in patients with than without hemophagocytosis (580 +/- 145 versus 457 +/- 89 IU/mL: P = 0.01). Multiorgan dysfunction and infection were independent risk factors of hemophagocytosis (odds ratio = 31.3 and 6.8, 95% confidence interval (CI) = 5.4 to 177.6 and 1.0 to 47.4, P <0.0001 and P = 0.03, respectively). CONCLUSIONS: Hemophagocytosis is a frequent cause of unexplained thrombocytopenia in patients with severe sepsis syndrome. Our results suggest that M-CSF is overproduced in the sepsis syndrome, particularly when hemophagocytosis is present. The role of M-CSF in the initiation and development of hemophagocytosis remains to be determined.

Feasibility of aortic diameter measurement by multiplane transesophageal echocardiography for preoperative selection and preparation of homograft aortic valves.

BACKGROUND: Preoperative knowledge of the aortic annular diameter could enable the preoperative selection and preparation of an appropriately sized homograft aortic valve. OBJECTIVE: The aims of this study were to prospectively determine whether the combined use of transthoracic and multiplane transesophageal echocardiography allows accurate preoperative aortic annular measurements for the selection and preparation of adequately sized homograft aortic valves and to retrospectively evaluate the influence of the echocardiographic approach (transthoracic vs transesophageal) and the reader's level of experience on the accuracy of these measurements. METHODS: Aortic annular measurements were performed before the operation by an experienced reader who used a combination of transthoracic and multiplane transesophageal images of 25 patients (mean age 52 +/- 13 years) referred for homograft aortic valve replacement. Measurements were also performed retrospectively by three additional readers with different levels of training in echocardiography. These readers acquired aortic annular diameters from prerecorded tapes and obtained measurements from each echocardiographic modality independently. All values were compared with the surgical measurement obtained with a ring valve sizer. RESULTS: With the combined echocardiographic approach, excellent agreement was found between preoperative echocardiographic and surgical measurements (mean difference +/- 2 standard deviations = 0.2 +/- 1.4 mm). All echocardiographic data were found to be within 2 mm of the surgical measurement. These measurements were used to select and prepare the aortic homograft valve before insertion. The accuracy of annular measurements appeared to increase in parallel to the level of experience. The aortic annular measurements obtained retrospectively by a second experienced reader were more accurate with the use of transesophageal than with transthoracic echocardiography (p < 0.01). In contrast, the echocardiographic modality had no influence on the accuracy of measurements of less experienced readers (p > 0.2). CONCLUSIONS: Preoperative measurement of the aortic annular diameter by transthoracic and multiplane transesophageal echocardiography is accurate and clinically feasible. Preoperative knowledge of the aortic annular diameter may be used to select and prepare the aortic homograft, improving valve availability and reducing ischemic time.

Diagnostic accuracy and therapeutic impact of transthoracic and transesophageal echocardiography in mechanically ventilated patients in the ICU.

STUDY OBJECTIVES: To assess the respective diagnostic accuracy of transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) and their therapeutic implications in mechanically ventilated patients, in the intensive care unit (ICU). DESIGN: A prospective study. SETTINGS: Intensive care units of two tertiary referral teaching hospitals. PATIENTS: One hundred eleven ICU patients (81 men and 30 women; mean age 57 +/- 16 years). Fifty-seven percent were hospitalized for medical illnesses, 16.5 percent after thoracic surgery, 10.5 percent after other surgery, and 16.0 percent for multiple trauma. Their Simplified Acute Physiologic Score was 16 +/- 5. INTERVENTIONS: The echocardiograms were performed in order to solve well-defined clinical problems. TTE was the first step of the procedure and TEE was performed only when (1) TTE did not solve the clinical problems, and (2) TTE yielded unsuspected findings requiring TEE. During each echocardiographic study, the following were noted: ventilatory mode, clinical problems, imaging quality, results, consequence on acute care, duration of the procedure, and potential complications of TEE. Diagnostic accuracy was defined as the proportion of solved problems, and therapeutic impact was defined as changes on acute care that resulted directly from the procedure. MEASUREMENTS AND RESULTS: One hundred twenty-eight consecutive TTE and 96 TEE were performed. TTE solved 60 of 158 clinical problems (38 percent), whether positive end-expiratory pressure (> 4 cm H2O) was present or not (28 of 74 vs 32 of 84: p > 0.50). TTE allowed evaluation of left ventricular function in 77 percent of cases and pericardial effusion in every case, but it did not solve most of the other clinical problems. Indeed, the diagnostic accuracy of TEE was markedly superior (95/98 vs 60/158: p < 0.001), but TEE required a physician's presence longer (43 +/- 17 min vs 27 +/- 12 min: p < 0.001). When TTE and TEE were scheduled (n = 96), TEE yielded an additional diagnosis or excluded with more certitude a suspected diagnosis, except in two cases. TEE had a therapeutic impact more frequently than TTE (35/96 vs 20/128: p < 0.001). Cardiovascular surgery was prompted by echocardiographic findings in ten patients. TEE was well tolerated in all patients; there were no complications. CONCLUSIONS: TEE is a valuable well-tolerated imaging technique in mechanically ventilated patients. For the assessment of left ventricular systolic function and pericardial effusion; however, TTE continues to be an excellent diagnostic tool, even when positive end-expiratory pressure is present. Both TTE and TEE have a therapeutic impact in approximately 25 percent of cases.

Quantification of traumatic hemomediastinum using transesophageal echocardiography: impact on patient management.

STUDY OBJECTIVES: To determine whether the quantitative evaluation of hemomediastinum using transesophageal echocardiography (TEE) is predictive of the presence of a traumatic disruption of the thoracic aorta (TDA) or its branches in patients who have sustained severe blunt chest trauma. DESIGN: Retrospective study. SETTING: ICU of a tertiary referral teaching hospital. PATIENTS: Forty-one patients sustaining severe blunt chest trauma (32 men, nine women; mean age, 43+/-16 years; mean Injury Severity Score, 39+/-22) who underwent a TEE study were divided into two groups, patients with (group TDA+, n=15) or without (group TDA-, n=26) major vascular injury diagnosed using an alternative method such as aortography, surgery, or necropsy. The control group included 41 age- and sex-matched patients with an unremarkable TEE study performed to rule out an intracardiac source of emboli. INTERVENTIONS: The presence of hemomediastinum was quantitatively assessed by measuring the distances between the esophageal scope and anteromedial aortic wall (distance 1), and between the posterolateral aortic wall and left visceral pleura (distance 2) at the level of the aortic isthmus. An observer who was unaware of both medical history and final diagnosis measured the distances. MEASUREMENTS AND RESULTS: In group TDA+, TEE demonstrated aortic injuries in 13 patients, revealed an isolated hemomediastinum in one patient (ruptured intercostal arteries), and was unremarkable in the remaining patient, who sustained a disrupted right subclavian artery. No associated major vessel injuries were diagnosed in the group TDA- (normal aortograms). When compared to the control group, mean distances were greater in patients with chest trauma (distance 1=5.5+/-4.4 mm vs 2.7+/-0.8 mm, p=0.001; distance 2=3.8+/-5.0 mm vs 1.2+/-0.3 mm, p=0.02). The corresponding distances were even greater in group TDA+ when compared with group TDA- (distance 1=8.6+/-5.9 mm vs 3.7+/-1.5 mm, and distance 2=7.1+/-7.0 mm vs 2.0+/-1.7; for both differences, p<0.01). A threshold value of 5.5 mm for distance 1 or 6.6 mm for distance 2 had a sensitivity of 80%, a specificity of 92%, a positive and negative predictive value of 86% and 89%, respectively, for the diagnosis of underlying major vascular injury. CONCLUSIONS: TEE allows quantitative assessment of traumatic hemomediastinum. The presence of a large hemomediastinum requires further evaluation by aortography, even if the thoracic aorta appears normal during the TEE examination, in order to rule out an underlying major vascular injury which may be outside the field of view of the echocardiographer.

Differential transesophageal echocardiographic diagnosis between linear artifacts and intraluminal flap of aortic dissection or disruption.

BACKGROUND: The relatively low specificity of transesophageal echocardiography (TEE) for the diagnosis of aortic dissection (AD) or traumatic disruption of the aorta (TDA) has been attributed to linear artifacts. We sought to determine the incidence of intra-aortic linear artifacts in a cohort of patients with suspected AD or TDA, to establish the differential TEE diagnostic criteria between these artifacts and true aortic flaps, and to evaluate their impact on TEE diagnostic accuracy. METHODS AND RESULTS: During an 8-year period, patients at high risk of AD (n = 261) or TDA (n = 90) who underwent a TEE study and had confirmed final diagnoses were studied. In an initial retrospective series, linear artifacts were observed within the ascending and descending aorta in 59 of 230 patients (26%) and 17 of 230 patients (7%), respectively. TEE findings associated with linear artifacts in the ascending aorta were as follows: displacement parallel to aortic walls; similar blood flow velocities on both sides; angle with the aortic wall > 85 degrees; and thickness > 2.5 mm. Diagnostic criteria of reverberant images in the descending aorta were as follows: displacement parallel to aortic walls, overimposition of blood flow, and similar blood flow velocities on both sides of the image. In a subsequent prospective series (n = 121), systematic use of these diagnostic criteria resulted in improved TEE specificity for the identification of true intra-aortic flaps. CONCLUSIONS: Misleading intra-aortic linear artifacts are frequently observed in patients undergoing a TEE study for suspected AD or TDA. Routine use of the herein-proposed diagnostic criteria promises to further improve TEE diagnostic accuracy in the setting of severely ill patients with potential need for prompt surgery.

Age dependency of left atrial and left ventricular acoustic quantification waveforms for the evaluation of diastolic performance in left ventricular hypertrophy.

We evaluated diastolic performance in 50 normal subjects and 50 patients with concentric left ventricular (LV) hypertrophy. Age-dependent normal values were determined for LV and left atrial (LA) acoustic quantification parameters. Pulsed wave Doppler echocardiography was also performed on all subjects. Patients with LV hypertrophy had higher peak velocities of atrial contraction and atrial contributions to filling. The acoustic quantification waveforms revealed lower rapid filling percentage of total filling and lower peak rapid filling rates. The LA acoustic quantification analysis confirmed the dependence on active atrial emptying in the patients with LV hypertrophy. There were significant correlations with age for most of the LV and LA acoustic quantification parameters. Acoustic quantification provided confirmatory results in subjects with an abnormal relaxation or restrictive Doppler pattern. In subjects with a normal Doppler pattern, the acoustic quantification was of added diagnostic value, identifying abnormalities in 77% to 80% of the patients.

Acoustic quantification indexes of left ventricular size and function: effects of signal averaging.

BACKGROUND: The aim of this study was to evaluate the clinical utility of using signal-averaged acoustic quantification (SAAQ) waveforms for improved assessment of left ventricular (LV) size and function. METHODS AND RESULTS: Four separate protocols were performed in 47 subjects. SAAQ waveforms were used to assess alterations in LV function induced by dobutamine (15 microg/kg per minute) and esmolol (200 microg/kg per minute) in eight normal subjects. Subsequently, we analyzed SAAQ waveforms obtained in 12 patients with LV dysfunction secondary to dilated cardiomyopathy and 12 age-matched normal subjects. Finally, we developed computer software for monitoring of LV function on the basis of continuous acquisition and repeated analysis of SAAQ waveforms. We compared the interbeat variability in indexes of LV function obtained from raw AQ and SAAQ during 10 minutes of steady-state monitoring in eight patients undergoing transesophageal echocardiography. The feasibility of long-term monitoring in the intensive care setting was then studied in seven patients undergoing abdominal surgery. Our analysis tracked variations in LV function induced by dobutamine and esmolol. Significant differences in all measured indexes were found between normal subjects and patients with dilated cadiomyopathy. Signal averaging during steady-state monitoring significantly reduced the interbeat variability of all indexes (21% to 42%). In the operating room, the SAAQ monitoring system tracked hemodynamic changes in close agreement with invasive measurements. CONCLUSIONS: SAAQ allows fast and easy quantification of LV function and can track hemodynamic trends in the operating room setting.

Acute limb ischemia and heparin-induced thrombocytopenia: the value of echocardiography in eliminating a cardiac source of arterial emboli.

We report an unusual thromboembolic event occurring during severe heparin-induced thrombocytopenia. A left intraventricular thrombus was diagnosed as the source of multiple arterial emboli, resulting in an initial cerebrovascular event and subsequent bilateral acute lower extremity ischemia requiring emergency surgery. No underlying heart disease was detected. Pathologic examination of the embolectomy specimen revealed fibrin platelet aggregates with rare white and red blood cells, consistent with a "white thrombus." We conclude that routine monitoring of platelet count should be performed in all patients receiving heparin to identify promptly individuals who have heparin-induced thrombocytopenia, and when thromboembolic complications occur in this setting, echocardiography is indicated to identify possible intracardiac sources for emboli, even in patients with previously known structurally intact hearts.

Contrast echocardiographic quantification of regional myocardial perfusion: validation with an isolated rabbit heart model.

Quantification of regional myocardial tissue blood flow (RMBF) based on contrast echocardiography has yet to be achieved. This study validated our recently proposed algorithm for quantification of RMBF with colored microspheres. Experiments were carried out in an isolated rabbit heart preparation (n = 11). Aortic root injections of perfluoropropane-filled albumin microsphere solution (FS069) and colored microspheres were performed at five levels of coronary flow achieved by altering perfusion pressure. During each injection of contrast material, consecutive end-diastolic images of the heart and an extracardiac reference chamber were acquired with a 7.5 MHz transducer and digitized. Time-intensity curves from the reference chamber and myocardial regions of interest, corresponding to the anatomic segments used for colored microsphere analysis, were analyzed for RMBF. Blood flow was calculated as the intravascular volume fraction (ratio of areas under myocardial and reference curves) divided by mean transit time (deconvolution of impulse response) and compared with those obtained with colored microspheres. Injections of FS069 resulted in highly reproducible enhancement of myocardial contrast. Analysis of time-intensity curves provided consistent measurements of RMBF (r = 0.91), which correlated highly with microsphere data (r = 0.84). The use of this new algorithm allows accurate quantification of RMBF in the isolated heart model. Further validation of this approach in an animal model with peripheral intravenous injections of contrast material will allow noninvasive clinical measurements of RMBF.

Transnasal transesophageal echocardiography.

Transesophageal echocardiography has been used as a diagnostic tool in the critical care unit. However, long-term serial evaluation of ventricular function with transesophageal echocardiography is difficult because of the current probe sizes and intolerance to prolonged oral intubation. We performed 139 intubations (64 oral and 75 transnasal) with a new prototype probe in 128 patients referred for transesophageal echocardiography. Transnasal intubation with the prototype probe was possible in 63/75 attempts. Oral intubation was successful in all 64 attempts. Patients tolerated transnasal intubation well when mildly sedated or awake. Two-dimensional echocardiographic views obtained with the nasal probe were similar to those obtained with a standard monoplane probe. Image quality was rated as good or acceptable in nearly all cases. Transgastric short-axis imaging of the left ventricle combined with acoustic quantification provided stable left ventricular area waveforms. Using custom developed software we showed the feasibility of monitoring left ventricular performance with minimal probe adjustment while graphically displaying and updating left ventricular area and fractional area change. Thus, transesophageal echocardiography with a prototype miniaturized monoplane probe passed transnasally is feasible, safe, and well tolerated by patients. This probe provides excellent two-dimensional echocardiographic images and may allow long-term echocardiographic monitoring of ventricular performance.

A new simple technique for the insertion of cuffed central venous catheters: an initial experience.

BACKGROUND: Although tunneled polyurethane catheters with polyester cuffs are useful when prolonged central venous access is necessary but their insertion still remains challenging at times. We report the first study of a new cuffed polyurethane catheter (Seldicuff) that can be easily inserted using the Seldinger technique without the need of a vein dilator and that incorporates a tunneling needle onto the catheter. A Seldicuff catheter was placed in 15 patients (mean age: 53 +/- 11 years) who required prolonged parenteral nutrition. All catheters were inserted into the right subclavian vein. The procedure lasted 6.4 +/- 0.8 minutes and no complication directly related to catheter placement was noted. Catheters remained in position for a mean duration of 103 days (range, 58 to 220 days). During this period, no infectious or mechanical complications were observed. CONCLUSION: These results demonstrate that placement of this novel cuffed catheter is as simple as inserting a conventional central venous catheter.

Extrapericardial cardiac tamponade caused by traumatic retrosternal hematoma.

Cardiac tamponade is an uncommon complication of blunt chest trauma, resulting typically from hemorrhage into the pericardial space. We report a case of hemodynamic compromise secondary to an extrapericardial compression caused by the acute formation of a retrosternal hematoma associated with a sternal fracture. The patient was involved in a violent deceleration accident. Initially, he only complained of an anterior thoracic pain, but subsequently became restless, pale, and dyspneic. A severe hypotension associated with sinus bradycardia (45 bpm) rapidly occurred. Both jugular veins became markedly turgescent, but no significant pulsus paradoxus was noted. Echocardiography disclosed a large hematoma, compressing anteriorly both the right ventricular cavity and outflow tract. Surgical evacuation of the retrosternal hematoma related to a bifocal fracture of the manubrium was followed by instantaneous hemodynamic improvement. Regional extrapericardial tamponade secondary to the acute formation of compressive retrosternal hematoma is an unusual cause of circulatory failure after severe blunt chest trauma. Since conventional clinical signs associated with typical tamponade physiology may be lacking in this setting, echocardiography is ideally suited for early recognition of this unusual condition.

[Portable echocardiographs: useful or futile?]. / Echocardiographe portable: utile ou futile?

Echocardiographic systems which are the size of a laptop computer are currently available. These hand-held ultrasound units are very easy to use at patient bedside in various clinical settings. According to the miniaturized devices, spectral Doppler may not be available and power Doppler may replace true color Doppler. Validation studies of hand-held echocardiography have been conducted in critically ill patients, in patients hospitalized in ward, but also in outpatients and as a screening tool for the detection of cardiac abnormalities in the community. Hand-held echocardiography appears to have important limitations in specific clinical settings, such as shock, pulmonary hypertension, assessment of valvulopathy or valvular prosthesis, dynamic left outflow tract obstruction, left ventricular restriction or construction. The miniaturized system with spectral Doppler capability has not yet been properly validated in these indications. At its present stage of development, hand-carried ultrasound units do not allow to perform a comprehensive examination which relies on the use of a full-feature system, especially when a precise hemodynamic evaluation is required. Diagnostic ability of hand-held echocardiography is similar to that of upper-end platforms for diagnoses based on two-dimensional imaging: left ventricular systolic function, detection of wall motion abnormalities, size of cardiac chambers, identification of pericardial or pleural effusions. Hand-carried ultrasound devices may be considered as a "visual stethoscope" which provides an extension of the physical examination, but not as a potential alternative to standard transthoracic echocardiography. Its large potential clinical field of use raises the concern of taylored training programs to intensivists which could be focused on goal-directed echocardiographic examinations.

[Diagnostic value of transesophageal echocardiography in traumatic rupture of the thoracic aorta]. / Valeur diagnostique de l'échocardiographie transoesophagienne dans la rupture traumatique de l'isthme aortique.

Traumatic rupture of the aorta (TRA) usually occurs at the isthmus. It is rapidly lethal without early surgery and, therefore, diagnosis must not be delayed. The reference diagnostic investigation is aortography but it is invasive in a patient with multiple trauma whose haemodynamic status is often precarious. Transoesophageal echocardiography, a non-invasive investigation which can be undertaken rapidly at the bedside has been proposed recently for the diagnosis of this condition because it gives excellent views of the aortic isthmus. The authors report their experience of transoesophageal echocardiography in 3 victims of severe road traffic accidents with thoracic trauma and who were operated for traumatic rupture of the aorta. Echocardiographic diagnosis of TRA is based on the recording of the association of a thick and mobile intraluminal echo corresponding to the torn intima and media and localised dilatation of the aorta, the wall of which is reduced to the adventitia under tension. On Doppler colour flow mapping the velocities are similar on both sides of the tear but turbulence at the site of rupture may give rise to aliasing. It is important to recognise the echocardiographic features of TRA to differentiate it from dissection of the aorta. Transoesophageal echocardiography also allows diagnosis of any associated traumatic cardiovascular lesions. Its limitations are due to the inability to visualise the proximal portion of the transverse aorta and the supra aortic vessels. Aortography remains essential when a lesion of these vessels is suspected and when the echocardiographic features of the aorta are atypical.