Outcome prediction in sepsis: Speckle tracking echocardiography based assessment of myocardial function

Introduction

Speckle tracking echocardiography (STE) is a relatively novel and sensitive method for assessing ventricular function and may unmask myocardial dysfunction not appreciated with conventional echocardiography. The association of ventricular dysfunction and prognosis in sepsis is unclear. We sought to evaluate frequency and prognostic value of biventricular function, assessed by STE in patients with severe sepsis or septic shock.

Methods

Over an eighteen-month period, sixty patients were prospectively imaged by transthoracic echocardiography within 24 hours of meeting severe sepsis criteria. Myocardial function assessment included conventional measures and STE. Association with mortality was assessed over 12 months.

Results

Mortality was 33% at 30 days (n = 20) and 48% at 6 months (n = 29). 32% of patients had right ventricle (RV) dysfunction based on conventional assessment compared to 72% assessed with STE. 33% of patients had left ventricle (LV) dysfunction based on ejection fraction compared to 69% assessed with STE. RV free wall longitudinal strain was moderately associated with six-month mortality (OR 1.1, 95% confidence interval, CI, 1.02-1.26, p = 0.02, area under the curve, AUC, 0.68). No other conventional echocardiography or STE method was associated with survival. After adjustment (for example, for mechanical ventilation) severe RV free wall longitudinal strain impairment remained associated with six-month mortality.

Conclusion

STE may unmask systolic dysfunction not seen with conventional echocardiography. RV dysfunction unmasked by STE, especially when severe, was associated with high mortality in patients with severe sepsis or septic shock. LV dysfunction was not associated with survival outcomes.     

Correlation of left ventricular systolic dysfunction determined by low ejection fraction and 30-day mortality in patients with severe sepsis and septic shock: A systematic review and meta-analysis

Introduction

The prognostic implications of myocardial dysfunction in patients with sepsis and its association with mortality are controversial. Several tools have been proposed to evaluate cardiac function in these patients, but their usefulness beyond guiding therapy is unclear. We review the value of echocardiographic estimate of left ventricular ejection fraction (LVEF) in the setting of severe sepsis and/or septic shock and its correlation with 30-day mortality.

Methods

We conducted a systematic review and meta-analysis to evaluate the prognostic functionality of newly diagnosed LV systolic dysfunction by transthoracic echocardiography on critical ill patients admitted to the intensive care unit with severe sepsis or septic shock.

Results

A search of EMBASE and PubMed, Ovide MEDLINE, and Cochrane CENTRAL medical databases yielded 7 studies meeting inclusion criteria reporting on a total of 585 patients. The pooled sensitivity of depressed LVEF for mortality was 52% (95% confidence interval [CI], 29%-73%), and pooled specificity was 63% (95% CI, 53%-71%). Summary receiver operating characteristic curve showed an area under the curve of 0.62 (95% CI, 0.58-0.67). The overall mortality diagnostic odd ratio for septic patients with LV systolic dysfunction was 1.92 (95% CI, 1.27-2.899). Statistical heterogeneity of studies was moderate.

Conclusion

The presence of new LV systolic dysfunction associated with sepsis and defined as low LVEF is neither a sensitive nor a specific predictor of mortality. These findings are limited because of the heterogeneity and underpower of the studies. Further research into this method is warranted.     

Brain natriuretic peptide: A marker of myocardial dysfunction and prognosis during severe sepsis

OBJECTIVE: To investigate the value of brain natriuretic peptide plasma levels as a marker of systolic myocardial dysfunction during severe sepsis and septic shock. DESIGN: Prospective observational study. SETTING: Intensive care unit. PATIENTS: A total of 34 consecutive patients with severe sepsis (nine patients) or septic shock (25 patients) without previous cardiac, respiratory, or chronic renal failure. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Myocardial systolic performance was assessed by fractional area contraction (FAC) using echocardiography performed on days 2 (FACD2) and 8. Plasma levels of brain natriuretic peptide were measured at days 1-4 and 8 after the beginning of severe sepsis. Among 34 patients (Simplified Acute Physiology Score II, 43 +/- 2.5), 15 (44%) presented with initial myocardial dysfunction (FACD2 < 50%). Lungs were the origin of sepsis in 65% of patients. The 28-day mortality was 29%. Comparisons were performed between patients with (FACD2 < 50%) and without (FACD2 > or = 50%) myocardial dysfunction. Plasma levels of brain natriuretic peptide were significantly higher in patients with FACD2 < 50% than in those with FACD2 > or = 50% (p <.05) from day 2 to day 4. Brain natriuretic peptide levels were also significantly higher on days 2 and 3 in patients who died during their intensive care unit stay (p <.05). CONCLUSIONS: Systolic myocardial dysfunction is present in 44% of patient with severe sepsis or septic shock. In this setting, brain natriuretic peptide seems useful to detect myocardial dysfunction, and high plasma levels appear to be associated with poor outcome of sepsis, but further studies are needed.     

Systolic dysfunction as evaluated by tissue Doppler imaging echocardiography and mortality in septic patients: A systematic review and meta-analysis

PurposeSeptic induced cardiomyopathy has a wide spectrum of presentation, being associated with systolic and/or diastolic dysfunction. There is currently no evidence of association between left ventricular (LV) systolic dysfunction and mortality in septic patients.MethodsWe conducted a systematic review and meta-analysis to investigate the association between systolic wave (s') obtained with Tissue Doppler Imaging (TDI) and mortality in septic patients. Secondary outcome was the association of LV ejection fraction with mortality.ResultsIn the primary analysis we included a total of 13 studies (1197 patients, mortality 39.9%); overall s' wave was not significantly different between survivors and non-survivors (Standardized Mean Difference 0.20, 95%Confidence-Interval − 0.18, 0.59). This result was confirmed also in sub-groups analyses according to regional criteria of TDI sampling. A post-hoc analysis including only septic shock patients confirmed that s' wave was not associated with mortality. Several sensitivity analyses confirmed these results. We found no evidence of publication bias. The secondary analysis (11 studies, 1081 patients, mortality 36.7%) showed that LV ejection fraction was not associated with mortality (Mean Difference 0.98, 95% Confidence-Interval − 1.79,3.75).ConclusionsThere is no association between mortality and LV systolic function as evaluated by TDI s' wave in septic patients.     

Clinical review: Myocardial depression in sepsis and septic shock

Myocardial dysfunction frequently accompanies severe sepsis and septic shock. Whereas myocardial depression was previously considered a preterminal event, it is now clear that cardiac dysfunction as evidenced by biventricular dilatation and reduced ejection fraction is present in most patients with severe sepsis and septic shock. Myocardial depression exists despite a fluid resuscitation-dependent hyperdynamic state that typically persists in septic shock patients until death or recovery. Cardiac function usually recovers within 7-10 days in survivors. Myocardial dysfunction does not appear to be due to myocardial hypoperfusion but due to circulating depressant factors, including the cytokines tumor necrosis factor alpha and IL-1beta. At a cellular level, reduced myocardial contractility seems to be induced by both nitric oxide-dependent and nitric oxide-independent mechanisms. The present paper reviews both the clinical manifestations and the molecular/cellular mechanisms of sepsis-induced myocardial depression.     

Cardiac troponins I and T are biological markers of left ventricular dysfunction in septic shock

BACKGROUND: Cardiac depression in severe sepsis and septic shock is characterized by left ventricular (LV) failure. To date, it is unclear whether clinically unrecognized myocardial cell injury accompanies, causes, or results from this decreased cardiac performance. We therefore studied the relationship between cardiac troponin I (cTnI) and T (cTnT) and LV dysfunction in early septic shock. METHODS: Forty-six patients were consecutively enrolled, fluid-resuscitated, and treated with catecholamines. Cardiac markers were measured at study entry and after 24 and 48 h. LV function was assessed by two-dimensional transesophageal echocardiography. RESULTS: Increased plasma concentrations of cTnI (>/=0.4 microgram/L) and cTnT (>/=0.1 microgram/L) were found in 50% and 36%, respectively, of the patients at one or more time points. cTnI and cTnT were significantly correlated (r = 0.847; P <0.0001). Compared with cTnI-negative patients, cTnI-positive subjects were older, presented higher Acute Physiology and Chronic Health Evaluation II scores at diagnosis, and tended to have a worse survival rate and a more frequent history of arterial hypertension or previous myocardial infarction. In contrast, the two groups did not differ in type of infection or pathogen, or in dose and type of catecholamine administered. Continuous electrocardiographic monitoring in all patients and autopsy in 12 nonsurvivors did not disclose the occurrence of acute ischemia during the first 48 h of observation. LV dysfunction was strongly associated with cTnI positivity (78% vs 9% in cTnI-negative patients; P <0.001). In multiple regression analysis, both cTnI and cTnT were exclusively associated with LV dysfunction (P <0.0001). CONCLUSIONS: These findings suggest that in septic shock, clinically unrecognized myocardial cell injury is a marker of LV dysfunction. The latter condition tends to occur more often in severely ill older patients with underlying cardiovascular disease. Further studies are needed to determine the extent to which myocardial damage is a cause or a consequence of LV dysfunction.     

Sepsis and myocardial depression in a young woman

Severe sepsis may be associated with depression of myocardial function, attributed to various inflammatory mediators. Myocardial dysfunction in sepsis is characterized by biventricular failure and complicates usual therapy with high-volume fluid resuscitation and vasopressors. However, in patients who survive septic shock, myocardial dysfunction can improve rapidly. We describe a young woman with septic shock due to Streptococcus pneumoniae, complicated by severe but reversible biventricular dysfunction.     

Left ventricular systolic and diastolic function in septic shock

Summary Objective: The identification of myocardial dysfunction in septic shock has not yet been fully elucidated. We therefore studied patients with persistently vasopressor-dependent septic shock, both with invasive haemodynamic monitoring and transoesophageal two-dimensional and Doppler echocardiography (TEE). Design: Prospective study. Setting: General ICU in University Hospital. Patients and methods: All patients were monitored with arterial and pulmonary artery catheters. Haemodynamics were obtained concomitantly with TEE measurements. TEE was performed at three levels: a) a midpapillary short axis view of the left ventricle (LV) in order to measure end-systolic and end-diastolic areas; b) at the level of both the mitral valve for early (E) and late (A) filling parameters and c) the level of the right upper pulmonary vein for systolic (S) and diastolic (D) filling characteristics. Each parameter was characterised by maximal flow velocity and time velocity integral. Results: Although the measurements of cardiac index demonstrated a wide range, three subsets of patients were identified post hoc after analysis on the basis of different Doppler patterns: first, patients with a LV without regional wall motion abnormalities and both E/A and S/D greater than 1 (group 1); second, patients with a comparable haemodynamic condition, apparently normal LV systolic function but with altered Doppler patterns: S/D less than 1 in conjunction with E/A more than 1 (group 2); finally, patients with compromised global LV systolic function, E/A less than 1 and S/D less than (group 3). Conclusions: Notwithstanding the known various interfering factors which limit the broad applicability of TEE to determine LV function in septic shock, our data suggest that cardiac dysfunction in septic shock shows a continuum from isolated diastolic dysfunction to both diastolic and systolic ventricular failure. These data strengthen the need of including the evaluation of pulmonary venous Doppler parameters in each investigation in order to obtain supplementary information to interpret diastolic function of the LV in septic shock patients. Received: 29 February 1996 Accepted: 10 February 1997     

Isolated diastolic dysfunction is associated with increased mortality in critically ill patients

PurposeLeft ventricular (LV) diastolic dysfunction is important in critically ill patients, but prevalence and impact on mortality is not well studied. We classified intensive care patients with normal left ventricular function according to current diastolic guidelines and explored associations with mortality.Material and methodsEchocardiography was performed within 24 h of intensive care admission. Patients with reduced LV ejection fraction, regional wall motion abnormality, or a history of cardiac disease were excluded. Patients were classified according to the 2016 EACVI guidelines, Recommendations for the Evaluation of LV Diastolic Function by Echocardiography.ResultsOut of 218 patients, 162 (74%) had normal diastolic function, 21 (10%) had diastolic dysfunction, and 35 (17%) had indeterminate diastolic function.Diastolic dysfunction were more common in female patients, older patients and associated with sepsis, respiratory and cardiovascular comorbidity as well as higher SAPS Score. In a risk-adjusted logistic regression model, patients with indeterminate diastolic dysfunction (OR 4.3 [1.6–11.4], p = 0.004) or diastolic dysfunction (OR 5.1 [1.6–16.5], p = 0.006) had an increased risk of death at 90 days compared to patients with normal diastolic function.ConclusionIsolated diastolic dysfunction, assessed by a multi-parameter approach, is common in critically ill patients and is associated with mortality.Trial registrationSecondary analysis of data from a single-center prospective observational study focused on systolic dysfunction in intensive care unit patients (Clinical Trials ID: NCT03787810     

The myocardial condition in chronic obstructive pulmonary disease and bronchial asthma

The purpose of the study was to assess the influence of structural and functional changes in the myocardium of the right and left ventricle (RVand LV) on the development of ischemia and arrhythmia in chronic obstructive pulmonary disease (COPD) and bronchial asthma (BA). The subjects of the study were 156 patients with either persistent BA (81 patients) or COPD (75 patients). Patients with decompensated cor pulmonale were excluded. ECG, 24-hour ECG monitoring, and echocardioscopy were performed. The study found that the occurrence of supraventricular and ventricular extrasystoles (SVES and VES) in patients with mild COPD or BA depended on the condition of RV diastolic function and on LV diastolic function and myocardial ischemia as well in COPD. In moderate BA the processes of myocardial remodeling correlate with myocardial ischemia, RV dysfunction and increased pulmonary arterial pressure (PAP), as well as with lipid dismetabolism. The appearance of SVES in patients with severe BA is connected with interventricular septal hypertrophy, LV dysfunction, and increased PAP, while VEC appear due to myocardial ischemia and hypercholesterolemia. In severe COPD the occurrence of SVES and VES does not depend on structural and functional changes in the myocardium, while myocardial ischemia is connected with LV hypertrophy. In BA ischemia depends on the development of RV and LV diastolic dysfunction, as well as hypercholesterolemia.     

Left ventricular reverse remodeling in dilated cardiomyopathy- maintained subclinical myocardial systolic and diastolic dysfunction

In idiopathic dilated cardiomyopathy (DCM), myocardial deformational parameters and their relationships remain incompletely characterized. We measured those parameters in patients with DCM, during left ventricular reverse remodeling (LVRR). Prospective study of 50 DCM patients (in sinus rhythm), with left ventricular ejection fraction (EF) <40%. LVRR was defined as an increase of ten units of EF and decrease of diastolic left ventricular diameter (LVDD) in the absence of resynchronization therapy. Performed morphological analysis, myocardial performance quantification (LV and RV Tei indexes) and LV averaged peak systolic longitudinal strain (SSR long) and circumferential strain (SSR circ). At baseline, mean EF was 25.4?±?9.8%, LVDD was 62.4?±?7.4 mm, LVDD/BSA of 34.2?±?4.5 mm/m² and 34% had MR grade >II/IV. LVRR occurred in 34% of patients within 17.6?±?15.6 months and was associated with a reduced rate of death or heart failure hospitalization (5.9% vs. 33.3; p?=?0.03). Patients with LVRR had a final EF of 48.9?±?7.9% (Δ LV EF of 22.4%) and there was a significant decrease (p?<?0.05) in: LVDD/BSA, LV systolic diameter/BSA, LV diastolic volume, LV systolic volume, LV mass; an increase (p?<?0.05) in sphericity index. However, measures of diastolic function (LA volume/BSA, e′velocity and’ E/e′ratio), final LV and RV Tei indexes were not significantly different from baseline. Additionally, final SSR circ and SSR long values were not different from basal. Patients who recovered EF >50% (n?=?10), SSR circ and SSR long were inferior to normal. Improvement in EF occurred in one-third of DCM pts and was associated with a decrease of major cardiac events. There was an improvement of diastolic and systolic volumes and in sphericity index, confirming truly LV reverse reshaping. However, myocardial performance indexes, SSR long and SSR circ in reverse-remodeled DCM were still abnormal, suggesting a maintained myocardial systolic and diastolic dysfunction.     

Normal regional right ventricular function and its change with age: a Doppler myocardial imaging study.

BACKGROUND: Doppler Myocardial Imaging (DMI) is a new technique currently being studied for the assessment of regional systolic and diastolic left ventricular (LV) function. No normal values or data on age-related changes in regional myocardial right ventricular (RV) velocities are available. METHODS AND RESULTS: Color DMI was used in 32 healthy volunteers (aged 16-76 years) to derive regional velocities from basal, medial, and apical segments of the RV free wall in the apical 4-chamber view, and from distal segments as well as from the tricuspid annulus in the parasternal long-axis view. Both mitral annular and regional LV velocities (4-chamber, long-axis parasternal view) were also recorded and compared with corresponding RV regional velocities. The M-mode displacement of the cardiac base was measured. Corresponding RV and LV DMI data sets were compared. For longitudinal function, RV free wall systolic velocities were consistently higher than velocities recorded in corresponding LV segments (analysis of variance, P <.05). Older subjects (40-76 years; 13 men, 2 women) had lower RV long-axis regional velocities than younger subjects (16-39 years; 15 men, 2 women), but had higher short-axis RV systolic velocities. For diastolic velocities, a negative correlation between age and the ratio of regional early diastolic to late diastolic velocity was shown for all RV free wall segments (eg, basal segment: r = -0.63, P <.0001). CONCLUSIONS: The right ventricle has higher long-axis regional velocities, a greater excursion of its lateral atrioventricular valve ring, and reduced circumferential shortening velocities compared with the left ventricle. Right ventricular longitudinal shortening is dominant over short-axis function in healthy young subjects. Normal age-related changes of diastolic velocities for each segment of the normal RV free wall have been defined.     

Prevalence, clinical characteristics, quality of life, and prognosis of patients with congestive heart failure and isolated left ventricular diastolic dysfunction.

Prevalence of isolated left ventricular (LV) diastolic dysfunction has been reported to be as high as one-third of all heart failure (HF) cases, with an increasing prevalence in the elderly population. However, there is a paucity of prospective data about the prevalence and prognosis of isolated LV diastolic dysfunction in an unselected population of patients hospitalized with HF. Therefore, we prospectively evaluated 179 consecutive patients discharged from our hospital with HF to assess the prevalence of systolic versus diastolic LV dysfunction among patients hospitalized with HF and to compare their demographics, clinical features, self-perceived quality of life (QOL), and 6-month readmission rate and mortality. Among them, 133 (59% men, median age 74 years) showed in sinus rhythm and had no significant primary valvular disease. LV diastolic dysfunction was diagnosed on the basis of the European Study Group on Diastolic HF echocardiographic criteria. QOL was assessed at hospital discharge and 6-month follow-up visit using the Minnesota Living with HF questionnaire. Survival of patients with HF was compared with that of age- and sex-matched general population. In all, 29 patients (22%) had isolated LV diastolic dysfunction and 102 (78%) had prevalent LV systolic dysfunction (ie, LV ejection fraction 相似文献   

Left Ventricular Dysfunction Correlates With Mortality in Pulmonary Embolism

BackgroundRisk stratification of patients with pulmonary embolism (PE) is essential to guide advanced interventional management and proper disposition.ObjectivesIn this study, we sought to assess individual echocardiographic markers of right ventricular (RV) strain and left ventricular (LV) function in patients with high-risk PE and identify their association with the need for advanced intervention (such as thrombolysis) and 30-day mortality.MethodsThis was a retrospective study of ED patients with PE who were subject to a pulmonary embolism response team activation over a 5-year period. Cardiac point-of-care ultrasound studies were performed as part of patient care and later assessed for septal bowing, RV hypokinesis, McConnell sign, RV enlargement, tricuspid annular place systolic excursion, and LV systolic dysfunction. Outcome variables included need for advanced intervention and 30-day mortality.ResultsThe pulmonary embolism response team was activated in 893 patients, of which 718 had a confirmed PE. Of these, 90 had adequate cardiac point-of-care ultrasound images available for review. Patients who needed an advanced intervention were more likely to have septal bowing (odds ratio [OR] 8.69, 95% confidence interval [CI] 2.37–31.86), RV enlargement (OR 4.02, 95% CI 1.43–11.34), and a McConnell sign (OR 2.79, 95% CI 1.09–7.13). LV dysfunction was the only statistically significant predictor of 30-day mortality (OR 9.63, 95% CI 1.74–53.32).ConclusionIn patients with PE in the ED, sonographic findings of RV strain that are more commonly associated with advanced intervention included septal bowing, McConnell sign, and RV enlargement. LV dysfunction was associated with a higher 30-day mortality. These findings can help inform decisions about ED management and disposition of patients with PE.     

Prognostic values of B-type natriuretic peptide in severe sepsis and septic shock

OBJECTIVE: To investigate the changes in B-type natriuretic peptide concentrations in patients with severe sepsis and septic shock and to investigate the value of B-type natriuretic peptide in predicting intensive care unit outcomes. DESIGN: Prospective observational study. SETTING: General intensive care unit. PATIENTS: Forty patients with severe sepsis or septic shock. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: B-type natriuretic peptide measurements and echocardiography were carried out daily for 10 consecutive days. In-hospital mortality and length of stay were recorded. The admission B-type natriuretic peptide concentrations were generally increased (747 +/- 860 pg/mL). B-type natriuretic peptide levels were elevated in patients with normal left ventricular systolic function (568 +/- 811 pg/mL), with sepsis-related reversible cardiac dysfunction (630 +/- 726 pg/mL), and with chronic cardiac dysfunction (1311 +/- 1097 pg/mL). There were no significance changes in B-type natriuretic peptide levels over the 10-day period. The daily B-type natriuretic peptide concentrations for the first 3 days neither predicted in-hospital mortality nor correlated with length of intensive care unit or hospital stay. CONCLUSION: B-type natriuretic peptide concentrations were increased in patients with severe sepsis or septic shock regardless of the presence or absence of cardiac dysfunction. Neither the B-type natriuretic peptide levels for the first 3 days nor the daily changes in B-type natriuretic peptide provided prognostic value for in-hospital mortality and length of stay in this mixed group of patients, which included patients with chronic cardiac dysfunction.     

Myocardial depression in sepsis: From pathogenesis to clinical manifestations and treatment

The cardiovascular system plays a key role in sepsis, and septic myocardial depression is a common finding associated with increased morbidity and mortality. Myocardial depression during sepsis is not clearly defined, but it can perhaps be best described as a global (systolic and diastolic) dysfunction of both the left and right sides of the heart. The pathogenesis of septic myocardial depression involves a complex mix of systemic (hemodynamic) factors and genetic, molecular, metabolic, and structural alterations. Pulmonary artery catheterization and modern echo-Doppler techniques are important diagnostic tools in this setting. There are no specific therapies for septic myocardial depression, and the cornerstone of management is control of the underlying infectious process (adequate antibiotic therapy, removal of the source) and hemodynamic stabilization (fluids, vasopressor and inotropic agents). In this review, we will summarize the pathogenesis, diagnosis, and treatment of myocardial depression in sepsis. Additional studies are needed in order to improve diagnosis and identify therapeutic targets in septic myocardial dysfunction.     

右心室不同部位起搏时左心室总体及节段心肌收缩功能的超声评估

目的 应用斑点追踪显像技术评价右心室不同部位起搏对左心室总体及节段心肌收缩功能的影响.方法 获取右室间隔起搏组(9例)、右室心尖起搏组(15例)、正常对照组(13例)心尖左室长轴观、胸骨旁左室短轴观图像,测量各节段峰值纵向应变(S_L)、峰值径向应变(S_R),计算左室总体峰值纵向应变(GS_L)、总体峰值径向应变(GS_R).结果 右室心尖起搏组GS_L[-(18.29±2.67)%]低于正常对照组[-(21.07±2.08)%]及右室间隔起搏组[-(20.54±2.29)%],差异均具有统计学意义(P＜0.05),右室间隔起搏组与正常对照组GS_L比较差异无统计学意义(P＞0.05).而右室心尖起搏组GS_R[-(26.85±7.73)%]与右室间隔起搏组GS_R[(28.59±6.06)%]均低于正常对照组[(36.26±9.37)%],差异有统计学意义(P＜0.05),两起搏组间GS_R差异无统计学意义(P＞0.05),但右室心尖起搏组GS_R有进一步降低趋势.两起搏组邻近起搏位点的左室节段心肌S_L及S_R较正常对照组相应节段明显降低,但右室间隔起搏组保持了与正常对照组相似的左室内应变分布,右室心尖起搏组左室内应变分布异常.结论 斑点追踪显像技术可定量评价右室不同部位起搏时左室总体及节段心肌收缩功能变化.     

E. Coli sepsis induces profound mechanoenergetic inefficiency in the porcine left ventricle

Myocardial dysfunction is believed to be a central part of septic multiorgan manifestations. The aim of the present study was to assess whether E. coli sepsis in an in vivo model would induce a dysfunction in the relationship between mechanical work and energy consumption in the left ventricle (LV). Accordingly, we measured hemodynamics, left ventricular pressure-volume area (PVA), and myocardial oxygen consumption (MVo2) in deeply anesthetized pigs. Eight pigs received 2.0 +/- 0.5 x 10(9) E. coli bacteria intravenously, and seven served as controls. Compared with baseline and the control group, no alternations were observed in LV diastolic function or indices of contractility in the septic group. The MVo2-PVA relationship was highly linear in both groups (all r2 = 0.96-0.99). At 5 h, the y-axis intercept of the MVo2-PVA relationship (nonmechanical MVo2) had increased in the sepsis group by 70% compared with baseline (P = 0.004) and by 60% compared with the control group (P = 0.003). Contractile efficiency (the inverse of the MVo2-PVA slope) remained unchanged over time and between groups. The study demonstrates a profound increase in nonmechanical oxygen consumption during E. coli sepsis in the LV.     

The applications of B-type natriuretic peptide measurement in the intensive care unit

PURPOSE OF REVIEW: Plasma B-type natriuretic peptide levels are used to screen for cardiac dysfunction in the emergency department and outpatient population. However, in the critically ill patient elevated plasma B-type natriuretic peptide levels do not necessarily reflect just ventricular dysfunction, as there are important confounding factors to consider. This review summarizes the recent advances in the application of B-type natriuretic peptide measurement in the intensive care unit. RECENT FINDINGS: B-Type natriuretic peptide levels are very useful in identifying cardiac dysfunction but not the specific pathology, whether it is right or left ventricular failure, diastolic or systolic dysfunction. Elevated serum B-type natriuretic peptide levels also occur in severe sepsis or septic shock. It also predicts cardiac dysfunction in sepsis. The lack of correlation of B-type natriuretic peptide concentrations with filling pressures in the intensive care unit precludes its use for monitoring cardiac therapy. Some studies involving patients with sepsis or septic shock demonstrate a positive correlation with mortality, while others failed to establish such a relation. The prognostic value of B-type natriuretic peptide in predicting mortality and morbidity remains controversial, partly due to different study designs. SUMMARY: B-Type natriuretic peptide is potentially a very useful diagnostic tool in the intensive care unit. To date there have been few studies and the results are often contradictory, mainly due to the special setting of the intensive care unit, which is constantly exposed to hemodynamically unstable patients, different case mixes as well as vigorous treatments. All of these are potential confounders to B-type natriuretic peptide levels and make interpretations of B-type natriuretic peptide difficult. We need more research on these confounding factors to accentuate the positive value of B-type natriuretic peptide in the intensive care unit.     

Derivation of a screen to identify severe sepsis and septic shock in the ED-BOMBARD vs. SIRS and qSOFA

Study objectiveTo predict severe sepsis/septic shock in ED patients.MethodsWe conducted a retrospective case-control study of patients ≥18 admitted to two urban hospitals with a combined ED census of 162,000.Study cases included patients with severe sepsis/septic shock admitted via the ED. Controls comprised admissions without severe sepsis/septic shock. Using multivariate logistic regression, a prediction rule was constructed. The model's AUROC was internally validated using 1000 bootstrap samples.Results143 study and 286 control patients were evaluated. Features predictive of severe sepsis/septic shock included: SBP ≤ 110 mm Hg, shock index/SI ≥ 0.86, abnormal mental status or GCS < 15, respirations ≥ 22, temperature ≥ 38C, assisted living facility residency, disabled immunity.Two points were assigned to SI and temperature with other features assigned one point (mnemonic: BOMBARD). BOMBARD was superior to SIRS criteria (AUROC 0.860 vs. 0.798, 0.062 difference, 95% CI 0.022–0.102) and qSOFA scores (0.860 vs. 0.742, 0.118 difference, 95% CI 0.081–0.155) at predicting severe sepsis/septic shock. A BOMBARD score ≥ 3 was more sensitive than SIRS ≥ 2 (74.8% vs. 49%, 25.9% difference, 95% CI 18.7–33.1) and qSOFA ≥ 2 (74.8% vs. 33.6%, 41.2% difference, 95% CI 33.2–49.3) at predicting severe sepsis/septic shock. A BOMBARD score ≥ 3 was superior to SIRS ≥ 2 (76% vs. 45%, 32% difference, 95% CI 10–50) and qSOFA ≥ 2 (76% vs. 29%, 47% difference, 95% CI 25–63) at predicting sepsis mortality.ConclusionBOMBARD was more accurate than SIRS and qSOFA at predicting severe sepsis/septic shock and sepsis mortality.