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.

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.

[Barotrauma by Venturi effect during apnea testing for the determination of brain death. Should it change the terms of application of this test?]. / Barotraumatisme par effet Venturi lors du test d'apnée d'un patient en état de mort encéphalique: faut-il changer les modalités d'application de ce test?

The clinical diagnosis of brain death is based on three clinical criteria, one of them being the abolition of the spontaneous breathing shown by an apnoea testing [1,2]. During this manoeuvre, oxygen is administered by intratracheal way through oxygen supply tubing inserted into the endotracheal tube. Few cases of barotrauma with tension pneumothorax during this test have been described in the literature bringing to the loss of potential donor or grafts for transplantation. The authors report a new case of tension pneumothorax occurred during an apnoea testing despite the precautionary measures necessary to prevent such a catastrophic complication. In addition to the possible pathophysiologic explanation of the event advanced by the authors, it seems lawful to redefine the practical modalities of implementation of this test to avoid the loss of potential grafts.

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.

[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.

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.