Role of echocardiography in a patient with suspected acute pulmonary embolism: a case report.

BACKGROUND: Approximately half of pulmonary embolism cases are diagnosed in an emergency context. The classic symptoms of pulmonary embolism are absent in intensive care unit patients who are under sedation and on mechanical ventilation. In this scenario, after the development of sudden, severe hypotension, pulmonary embolism must be considered and included in a differential diagnosis according to the cause of admission. Echocardiography may be of further help in a differential diagnosis of the cause of shock. CASE PRESENTATION: We present a case of a 44-year-old Caucasian man who was admitted to the intensive care unit with a diagnosis of community-acquired pneumonia and respiratory failure and who required invasive mechanical ventilation. During admission, the patient developed sudden, severe hypotension that was refractory to treatment. An adequate diagnosis with transthoracic echocardiography was unachievable because of a poor echocardiographic window. However, the combined use of electrocardiography and transesophageal echocardiography established pulmonary embolism as a high-probability diagnosis based on findings of right ventricular pressure overload and right ventricular dysfunction. The unfavorable hemodynamic situation of the patient prevented his transfer to carry out other complementary tests that could confirm the diagnosis of pulmonary embolism. Fibrinolytic and anticoagulant therapies were administered immediately, and a favorable clinical outcome was achieved. CONCLUSION: This case highlights the fundamental role that echocardiography played in a patient in the intensive care unit who presented with shock secondary to pulmonary embolism with an unfavorable hemodynamic situation and in whom an unnecessary transfer to perform other complementary diagnostic tests was avoided. The combined use of electrocardiography and echocardiography provided a complete differential diagnosis, identifying the cause of shock and allowing the initiation of specific treatment without further delay. Knowledge of the echocardiographic results that are characteristic of pulmonary embolism can aid in the diagnosis.

Early Transthoracic Echocardiography after Cardiac Surgery Predicts Postoperative Atrial Fibrillation.

PURPOSE: Postoperative atrial fibrillation (POAF) is frequent after cardiac surgery. We aimed to establish a predictive model of POAF based on postoperative transthoracic echocardiography (TTE) findings. METHODS: This study included 147 patients (aged 67 ± 11 years; 109 men) undergoing coronary artery bypass grafting and/or aortic valve replacement. TTE and Doppler tissue imaging were performed on intensive care unit arrival after surgery. All patients were continuously monitored during hospitalization. The end point was the appearance of POAF. RESULTS: POAF appeared in 37 patients (25.2%). These patients were older (69 ± 16 vs. 65 ± 12 years; P < 0.001) and had increased long axis of the left atrium (LA) dimension (5.4 ± 1 vs. 4.8 ± 0.9 cm, P = 0.02), lower early diastolic velocity of the mitral annulus (e') (6.9 ± 2.1 vs. 8 ± 1.8 cm/sec; P < 0.01), and higher early diastolic pulsed Doppler mitral ratio (E)/e' (E/e') (17.4 ± 6.8 vs. 13.8 ± 6; P = 0.01). Left ventricle diastolic dysfunction grade (DFG) of 2 or 3 relative to grade 0 was significant: odds ratio (OR) 22.5, 95% confidence interval (CI) 4.52-57.2; P < 0.001, and OR: 23.6, 95% CI: 3.57-60.1; P = 0.001), respectively. On multivariate analysis, the independent predictors of POAF were age (OR: 1.10, 95% CI: 1.01-1.18; P < 0.05), long-axis LA dimension (OR: 6.24, 95% CI: 1.97-8.23; P = 0.0017), DFG-2 (OR: 4.1, 95% CI: 1.57-15.81; P < 0.001), and DFG-3 (OR: 8.3, 95% CI: 4.11-25.37; P < 0.001). CONCLUSIONS: Apart from age, the simple determination by postoperative TTE of long-axis LA dimension and DFG after cardiac surgery proved to be powerful independent predictors of POAF and may be useful for risk stratification of these patients.

Left ventricular global longitudinal systolic strain predicts adverse remodeling and subsequent cardiac events in patients with acute myocardial infarction treated with primary percutaneous coronary intervention.

To determine whether left ventricular (LV) global longitudinal strain (GLS) predicts adverse LV remodeling and cardiac events. In a prospective cohort study of patients with acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI), we recorded clinical data and GLS, global circumferential strain and radial strain using two-dimensional speckle-tracking echocardiography of the left ventricle. At 6-month and 3-year follow-ups, patients were grouped by presence or absence of adverse LV remodeling. We used logistic regression to identify factors associated with adverse LV remodeling and a Cox model to determine the relationships between these factors and cardiac events. Of 97 patients (mean age 56 ± 12 years; 76 men), 38 showed LV remodeling. Diabetes mellitus [odds ratio (OR) 1.95% confidence interval (CI) 1.2-4.8, p = 0.05], peak troponin I (OR 1.2, 95% CI 1.1-1.3, p = 0.004), and GLS (OR 1.6, 95% CI 1.3-2.3, p = 0.009) independently predicted LV remodeling. During follow-up (22.8 ± 12.3 months), 20 patients suffered adverse events, which were independently predicted by GLS alone (OR 4.9, 95% CI 1.7-13.9, p = 0.002). Optimal GLS cutoffs for predicting adverse LV remodeling and cardiac events were >-12.46% [area under receiver operating-characteristic curve (AUC) 0.88, 95% CI 0.79-0.96, p < 0.001] and >-9.27% (AUC 0.86, 95% CI 0.64-0.98, p < 0.001), respectively. GLS measured immediately after primary PCI is an excellent predictor of adverse LV remodeling and cardiac events in patients with AMI.

Prognostic value of echocardiographic-derived calcium index in coronary artery disease diagnosed by 64-multidetector computed tomography.

PURPOSE: To determine whether echocardiographic calcium index (ECI) calculated using transthoracic echocardiography (TTE) predicts coronary ischemic events. We also wished to determine coronary artery calcium score (CACS), the presence of obstructive coronary artery disease (CAD) and plaque composition, all of which were assessed by multidetector computed tomography (MDCT). METHODS: We carried out a prospective cohort study of 82 consecutive outpatients with chest pain and low-moderate risk of CAD, referred for noninvasive coronariography by MDCT. ECI was blindly assessed by TTE and correlated with subsequent cardiovascular events during a follow up period of 36 months. RESULTS: ECI values of ≥7 had a sensitivity of 77.3%, a specificity of 90%, positive predictive value of 73.9%, and negative predictive value of 91.5% with respect to future coronary ischemic events. In addition, patients with ECI ≥ 7 showed a greater presence of severe calcified and obstructive CAD and a linear increase of obstructed vessels and mixed and calcified plaques, with a linear trend according to ECI values. CONCLUSION: ECI values of ≥7 determine poor CAD prognosis in relation to ischemic events. Furthermore, ECI ≥ 7 may serve as a marker of content of coronary artery calcium, intraluminal obstruction, and plaque composition. Therefore, ECI seems to provide prognostic information as well as information about the characteristics of the plaque of atheroma.

Branching dynamics of viral information spreading.

Despite its importance for rumors or innovations propagation, peer-to-peer collaboration, social networking, or marketing, the dynamics of information spreading is not well understood. Since the diffusion depends on the heterogeneous patterns of human behavior and is driven by the participants' decisions, its propagation dynamics shows surprising properties not explained by traditional epidemic or contagion models. Here we present a detailed analysis of our study of real viral marketing campaigns where tracking the propagation of a controlled message allowed us to analyze the structure and dynamics of a diffusion graph involving over 31,000 individuals. We found that information spreading displays a non-Markovian branching dynamics that can be modeled by a two-step Bellman-Harris branching process that generalizes the static models known in the literature and incorporates the high variability of human behavior. It explains accurately all the features of information propagation under the "tipping point" and can be used for prediction and management of viral information spreading processes.

Impact of human activity patterns on the dynamics of information diffusion.

We study the impact of human activity patterns on information diffusion. To this end we ran a viral email experiment involving 31,183 individuals in which we were able to track a specific piece of information through the social network. We found that, contrary to traditional models, information travels at an unexpectedly slow pace. By using a branching model which accurately describes the experiment, we show that the large heterogeneity found in the response time is responsible for the slow dynamics of information at the collective level. Given the generality of our result, we discuss the important implications of this finding while modeling human dynamical collective phenomena.

Clinical cure of ventilator-associated pneumonia treated with piperacillin/tazobactam administered by continuous or intermittent infusion.

The standard mode of administration of piperacillin treatment is by intermittent infusion. However, continuous infusion may be advantageous as beta-lactam antibiotics exhibit time-dependent antibacterial activity. In previous studies, we found a higher rate of clinical cure of ventilator-associated pneumonia (VAP) by continuous infusion rather than intermittent infusion of meropenem and ceftazidime. Therefore, the objective of this historical cohort study was to establish the clinical efficacy of piperacillin/tazobactam (PIP/TAZ) administered by continuous and intermittent infusion in the treatment of VAP in patients without renal failure. Logistic regression analysis showed a higher probability of clinical cure of VAP by continuous compared with intermittent infusion when the microorganism responsible for VAP had a minimum inhibitory concentration (MIC) of 8 microg/mL [8/9 (88.9%) vs. 6/15 (40.0%); odds ratio (OR)=10.79, 95% confidence interval (CI) 1.01-588.24; P=0.049] or 16 microg/mL [7/8 (87.5%) vs. 1/6 (16.7%); OR=22.89, 95% CI 1.19-1880.78; P=0.03]. Thus, administration of PIP/TAZ by continuous infusion may be considered more effective than intermittent infusion for the treatment of VAP caused by Gram-negative bacteria when the MIC of the microorganism responsible for VAP is 8-16 microg/mL in patients without renal failure.

TNFbeta+250 polymorphism and hyperdynamic state in cardiac surgery with extracorporeal circulation.

We have investigated genetic and clinical factors associated with hyperdynamic state (HS) after heart surgery with extracorporeal circulation (ECC). We performed a prospective cohort study of consecutive patients who underwent elective heart surgery with ECC. HS was defined as hyperthermia (>38 degrees C), cardiac index (CI) >3.5 l/min/m(2) and systemic vascular resistance index (SVRI) <1600 dynes x s/cm(5) x m(2). The study included demographic variables, gene polymorphisms A/G of tumor necrosis factor-beta (TNFbeta+250), G/A-1082 of interleukin-10 (IL-10), polymorphism of interleukin-1 receptor antagonist (IL-1ra), comorbidity, type of surgery, serum levels of interleukin-6 (IL-6), and postoperative course. We used Pearson chi(2) or Fisher exact test, and Student t-test for univariate analysis, with forward stepwise logistic regression for multivariate adjustment. Eighty patients were studied, of whom 22 (27.5%) developed HS. The presence of allele G of TNFbeta+250 polymorphism was associated with an increased incidence of HS (68% vs. 37%; P=0.011). In the multivariate analysis, a longer duration of ECC, and the presence of the G allele, were associated with the development of HS. The G allele of TNFbeta+250 polymorphism, and prolonged extracorporeal circuit times, may favor the development of a hyperdynamic state after heart surgery with ECC.

Comparison of clinical cure rates in adults with ventilator-associated pneumonia treated with intravenous ceftazidime administered by continuous or intermittent infusion: a retrospective, nonrandomized, open-label, historical chart review.

BACKGROUND: Beta-lactam antibiotics are reported to exhibit time-dependent bactericidal activity. However, there are limited data on the clinical efficacy of ceftazidime administered by continuous infusion. OBJECTIVE: The objective of this study was to compare the clinical efficacy of ceftazidime administered by continuous infusion and by intermittent infusion in the treatment of ventilator-associated pneumonia (VAP) caused by gram-negative bacteria. METHODS: This was a retrospective chart review of patients with VAP caused by gram-negative bacteria who were treated with initial empiric ceftazidime therapy in the intensive care unit (ICU) over a 5-year period (from June 2002 to June 2007). The intermittent-infusion group received ceftazidime 2 g infused over 30 minutes every 12 hours; the continuous-infusion group received a ceftazidime loading dose of 1 g over 30 minutes, followed by 2 g infused over 720 minutes every 12 hours. Data extracted from patients' charts included sex, age, severity of the patient's condition at ICU admission (Acute Physiology and Chronic Health Evaluation II [APACHE II] score), diagnosis group, weight, creatinine clearance, MIC of the organism responsible for VAP, and severity of organ dysfunction at the time VAP was suspected (Sepsis-related Organ Failure Assessment [SOFA] score). Each clinical history was reviewed by a group of 6 staff intensivists who were blinded to whether the patient received ceftazidime by continuous or intermittent infusion. The clinical effect of treatment was categorized as cure (complete resolution of all clinical signs and symptoms of pneumonia) or failure (persistence or progression of any sign or symptom of pneumonia). RESULTS: The final sample consisted of 121 patients, of whom 88 (72.7%) were males. The mean (SD) age of the population was 62.87 (9.35) years. The mean APACHE II score on admission to the ICU was 16.08 (2.17), the SOFA score at suspicion of VAP was 8.80 (2.06), and the MIC of the organism responsible for VAP was 2.77 (2.24) microg/mL. There were no significant differences in these and other characteristics at baseline between those who received ceftazidime by continuous infusion (n = 56) and those who received ceftazidime by intermittent infusion (n = 65). On logistic regression analysis, continuous infusion was associated with a greater clinical cure rate than intermittent infusion (50/56 [89.3%] vs 34/65 [52.3%], respectively; odds ratio [OR] = 12.2; 95% CI, 3.47-43.21; P < 0.001). Patients with VAP caused by organisms with an MIC of 8 microg/mL had lower cure rates compared with those with VAP caused by organisms with an MIC < or =2 microg/mL (OR = 0.2; 95% CI, 0.04-0.71; P = 0.02) but not compared with those with an MIC of 4 microg/mL. No significant interaction was found between the type of ceftazidime infusion and the MIC of the causative organism. CONCLUSION: In this small, selected population of adult patients with VAP caused by gram-negative bacteria who were treated in a nonrandomized, open-label manner, ceftazidime administered by continuous infusion had greater clinical efficacy than ceftazidime administered by intermittent infusion.

Microorganisms responsible for intravascular catheter-related bloodstream infection according to the catheter site.

OBJECTIVE: Current guidelines for the management of intravascular catheter-related bloodstream infection (IVC-RBSI) recommend that empirical antimicrobial therapy must have activity against Gram-positive bacteria, but additional empirical coverage for Gram-negative bacteria may be needed for severely ill or immunocompromised patients, and antifungal therapy may be needed in some situations. We hypothesized that the spectrum of etiological microorganisms responsible for IVC-RBSI and, in relation to that, the choice of empirical antimicrobial therapy depends on the catheter insertion site. We therefore compared the proportion of IVC-RBSI due to Gram-negative bacteria and yeasts according to catheter site. DESIGN: Prospective cohort study from May 1, 2000, to April 30, 2004. SETTING: A 24-bed medical-surgical intensive care unit in a 650-bed tertiary hospital. PATIENTS: Patients requiring a central venous or arterial catheter. MEASUREMENTS AND MAIN RESULTS: We diagnosed 88 IVC-RBSIs, comprising 36 femoral catheter sites (26 femoral venous and ten femoral arterial sites) and 52 other catheter sites (36 jugular venous, 11 subclavian venous, and five radial arterial sites). No differences were found between IVC-RBSI of femoral vs. other catheter sites for age, sex, Acute Physiology and Chronic Health Evaluation II, diagnosis at admission, use of antimicrobials, the time the catheter responsible for IVC-RBSI had been in place, or the duration of intensive care unit stay before IVC-RBSI. The proportion of IVC-RBSIs due to Gram-negative bacteria was higher in femoral, 14 of 36 (38.89%), than in the other catheter sites, 4 of 52 (7.69%) (odds ratio, 7.48; 95% confidence interval, 2.19-25.54; p = .001). Also, the proportion of IVC-RBSIs due to yeasts was higher in femoral, 6 of 36 (16.67%), than in the other catheter sites, 1 of 52 (1.92%) (odds ratio, 10.20; 95% confidence interval, 1.17-88.85; p = .035). CONCLUSIONS: Empirical antifungal therapy would seem to be indicated in patients with suspected femoral catheter-related bloodstream infection.

Estreptococo alfahemolítico como causa de púrpura fulminans / Alpha-hemolytic streptococci as a cause of purpura fulminans

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