Head-to-head comparison of dipyridamole echocardiography and stress perfusion scintigraphy for the detection of coronary artery disease: a meta-analysis. Comparison between stress echo and scintigraphy

Objectives: This meta-analysis was performed to assess and compare the diagnostic accuracy of dipyridamole echocardiography test (DET) vs. stress perfusion scintigraphy (SPS) for the diagnosis of coronary artery disease (CAD). Methods: We performed a meta-analysis of peer reviewed articles, published in English language reporting head-to-head comparison of DET vs. SPS for the diagnosis of CAD. Data of 10 studies comprising 651 patients from 10 different institutions were analyzed. DET dose was 0.56 mg/kg (low dose) in two studies, 0.75 mg/kg in 10 min or 0.84 mg/kg in 10 min (high dose) in six studies, and 0.84 mg/kg in 6 min (accelerated high dose) in one study and 0.84 mg/kg in 10 min + 1 mg atropine co-administration (augmented dose) in one study. SPS was performed with dipyridamole in six studies, with exercise in three studies and with dobutamine in one study. Results: The overall diagnostic accuracy of the two tests was almost similar, 77% (95% CI = 74–81) for DET vs. 81% (95% CI = 78–84) for SPS (p = ns). SPS gave higher sensitivity, 88% (95% CI = 85–89) than DET, 70% (95% CI = 66–75) in cumulative data (p < 0.0001) while DET gave higher specificity, 90% (95% CI = 86–94) vs. 67% (95% CI = 60–73) (p < 0.0001). With state of the art protocols, i.e. accelerated dose and atropine augmented high dose, sensitivity of DET improved and overall accuracy was better than SPS (p < 0.05). Conclusion: DET and SPS have a similar diagnostic accuracy. DET has a markedly higher specificity regardless of the dose employed. SPS shows a superior sensitivity, however this sensitivity gap diminishes when more aggressive dipyridamole dosage is used for the stress echocardiography.     

Plasma atrial natriuretic peptide and brain natriuretic peptide are increased in septic shock: impact of interleukin-6 and sepsis-associated left ventricular dysfunction

Objective Interest has recently focused on the use of neurohormonal markers such as atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) as indices of left ventricular systolic dysfunction and prognosis in heart failure. Also, peptides belonging to the interleukin-6 (IL-6) family have been shown to induce ANP and BNP secretion. We hypothesized that BNP and ANP spillover in the peripheral circulation reflects left ventricular dysfunction and IL-6 production in septic shock.Design and setting Retrospective, clinical study in the medical intensive care unit of a university hospital.Patients and participants 17 patients with septic shock and 19 control subjects.Interventions Collection of clinical and demographic data in relation to ANP, BNP, IL-6, and soluble TNF receptors (sTNF-R-p55, sTNF-R-p75) in plasma over a period of 4 days.Measurements and results In septic shock we found a significant increase in ANP (82.7±9.9 vs. 14.9±1.2 pg/ml) and BNP (12.4±3.6 vs. 5.5±0.7 pg/ml). Plasma ANP peaked together with IL-6. Peaks of ANP and IL-6 were significantly correlated (r=0.73; p<0.01). BNP was inversely correlated to cardiac index (r=–0.56; p<0.05).Conclusions ANP and BNP increase significantly in patients with septic shock. BNP reflects left ventricular dysfunction. ANP is related to IL-6 production rather than to cardiovascular dysfunction.     

C-reactive protein used as an early indicator of infection in patients with systemic inflammatory response syndrome

Objective To assess the diagnostic value of a single determination of serum C-reactive protein as a marker of sepsis in critically ill patients.Design Prospective, observational study.Setting Intensive care unit of a university hospital.Patients and participants One hundred twenty-five adult patients with systemic inflammatory response syndrome (SIRS) (55 patients without evidence of infection and 70 patients with the diagnosis of sepsis confirmed by documented infection). Twenty-five patients with non-complicated acute myocardial infarctions (AMI) and 50 healthy volunteers were used as controls.Interventions None.Measurements and results Serum C-reactive protein concentration was measured within the first 24 h of SIRS onset. Healthy subjects, AMI and non-infectious SIRS patients showed lower C-reactive protein median values ([(0.21 [95% confidence intervals (95% CI), 0.21–0.4] mg/dl, 2.2 [95% CI, 2.1–4.9] mg/dl and 1.7 [95% CI, 2.4–5.5] mg/dl, respectively) than patients with sepsis (18.9 [95% CI, 17.1–21.8]), p<0.001. The presence of severe sepsis (r_s=0.27; p=0.03), SOFA score (r_s=0.25; p=0.03) and arterial lactate (r_s=0.24; p=0.04) correlated significantly with C-reactive protein concentrations in sepsis cases. The best threshold value for C-reactive protein for predicting sepsis was 8 mg/dl (sensitivity 94.3%, specificity 87.3%). The area under the receiver-operating characteristic curve for C-reactive protein was 0.94 (95% CI, 0.89–0.98).Conclusions Determination of serum C-reactive protein can be used as an early indicator of infection in patients with SIRS.Supported in part by Red Respira (isciii-RTIC C03/11), CIRIT SGR 2001/414 and Distinció a la Recerca Universitaria (JR).     

Immunochemiluminometric assays (ICMA) specific for growth hormone releasing hormone 1–44 NH2 and 1–40 OH

We describe specific two-site immunochemiluminometric assays able to directly measure human growth hormone-releasing hormone 1–44 NH₂ and 1–40 OH concentrations in unextracted plasma. A common N-terminal antibody was purified from polyclonal rabbit antisera to growth hormone-releasing hormone 1–44 NH₂ on a growth hormone-releasing hormone 1–29 NH₂ linked affinity column and labelled with chemiluminescent acridinium ester. C-terminal specific monoclonal antibodies to growth hormone-releasing hormone 1–44 NH₂ and 1–40 OH were raised in Balb/C mice and used as solid phase antibodies. Assay of fasting specimens from normal individuals gave medians (and ranges) of 23 pg/ml (2–200) and 30 pg/ml (3–134) for growth hormone-releasing hormone 1–44 NH₂ and 1–40 OH, respectively. Samples from a series of acromegalics showed that most have values in the normal range though median values were higher, 56 pg/ml for growth hormonereleasing hormone 1–44 NH₂ (P < 0.001) and 52 pg/ml for 1–40 OH (P < 0.001). Using these assays it will be possible for the first time to directly study the physiology and pathophysiology of these two peptides.     

The relationship between the level of plasma B-type natriuretic peptide and mitral stenosis

B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are both secreted primarily from the ventricle myocardium in response to the increase in volume and pressure. We aimed to investigate the relationship between the severity of mitral stenosis (MS) and the level of plasma BNP. A total of 56 patients (50 female, 6 male) were included in the study. Mitral stenosis and its related parameters were evaluated by echocardiographic methods. Patients were divided into three groups as with mild, moderate and severe MS according to their planimetric valvular area. Plasma BNP levels were measured using “Triage-B-type natriuretic peptide test” method (Biosite Diagnostics, San Diego). The relationship of BNP with mitral stenosis and other echocardiographic parameters were studied. The comparison of the 3 groups with one another revealed that the BNP level in the group with moderate MS was higher than that in the group with mild MS, however it was statistically insignificant (74.9 ± 49.7 versus 49.9 ± 40.5 pg/ml, p > 0.05). BNP level in the group with severe MS was significantly higher than that in the mild MS (144.3 ± 83.9 versus 49.9 ± 40.5 pg/ml, p < 0.001) and that in the moderate MS group (144.3 ± 83.9 versus. 74.9 ± 49.7 pg/ml, p < 0.05). When patients were taken together, as the area of the mitral valve decreased, the level of BNP underwent a corresponding increase (r:−0.48, p < 0.001). We have ascertained that the level of plasma BNP and the degree of MS are significantly correlated, and as MS becomes more serious, the plasma BNP level rises.     

B型利钠肽在急性呼吸困难鉴别诊断中的应用研究

目的　探讨床旁B型利钠肽(BNP)测定对急性呼吸困难鉴别诊断的敏感性、特异性和准确性。方法　采用美国博适 Triage干式快速定量心力衰竭/心肌梗死诊断仪对36 7例心源性和非心源性呼吸困难患者床旁BNP测定。结果　不同心功能分级患者BNP水平不同;BNP水平小于6 0pg/ml患者基本可诊断为非心源性呼吸困难;BNP水平大于1 0 0pg/ml但小于50 0pg/ml患者需考虑心源性呼吸困难可能;大于50 0pg/ml患者基本可诊断为心源性呼吸困难。结论　BNP水平高低是鉴别心源性和非心源性呼吸困难可靠的指标。     

Midregional pro-Adrenomedullin in addition to b-type natriuretic peptides in the risk stratification of patients with acute dyspnea: an observational study

Introduction

The identification of patients at highest risk for adverse outcome who are presenting with acute dyspnea to the emergency department remains a challenge. This study investigates the prognostic value of the newly described midregional fragment of the pro-Adrenomedullin molecule (MR-proADM) alone and combined to B-type natriuretic peptide (BNP) or N-terminal proBNP (NT-proBNP) in patients with acute dyspnea.

Methods

We conducted a prospective, observational cohort study in the emergency department of a University Hospital and enrolled 287 unselected, consecutive patients (48% women, median age 77 (range 68 to 83) years) with acute dyspnea.

Results

MR-proADM levels were elevated in non-survivors (n = 77) compared to survivors (median 1.9 (1.2 to 3.2) nmol/L vs. 1.1 (0.8 to 1.6) nmol/L; P < 0.001). The areas under the receiver operating characteristic curve (AUC) to predict 30-day mortality were 0.81 (95% CI 0.73 to 0.90), 0.76 (95% CI 0.67 to 0.84) and 0.63 (95% CI 0.53 to 0.74) for MR-proADM, NT-proBNP and BNP, respectively (MRproADM vs. NTproBNP P = 0.38; MRproADM vs. BNP P = 0.009). For one-year mortality the AUC were 0.75 (95% CI 0.69 to 0.81), 0.75 (95% CI 0.68 to 0.81), 0.69 (95% CI 0.62 to 0.76) for MR-proADM, NT-proBNP and BNP, respectively without any significant difference. Using multivariate linear regression analysis, MR-proADM strongly predicted one-year all-cause mortality independently of NT-proBNP and BNP levels (OR = 10.46 (1.36 to 80.50), P = 0.02 and OR = 24.86 (3.87 to 159.80) P = 0.001, respectively). Using quartile approaches, Kaplan-Meier curve analyses demonstrated a stepwise increase in one-year all-cause mortality with increasing plasma levels (P < 0.0001). Combined levels of MR-proADM and NT-proBNP did risk stratify acute dyspneic patients into a low (90% one-year survival rate), intermediate (72 to 82% one-year survival rate) or high risk group (52% one-year survival rate).

Conclusions

MR-proADM alone or combined to NT-proBNP has a potential to assist clinicians in risk stratifying patients presenting with acute dyspnea regardless of the underlying disease.     

B-type natriuretic peptide as an indicator of right ventricular dysfunction in acute pulmonary embolism

Objective: B‐type natriuretic peptide (BNP) is a neurohormone secreted from cardiac ventricles in response to ventricular strain. The aim of present study was to evaluate the role of BNP in the diagnosis of the right ventricular (RV) dysfunction in acute pulmonary embolism (PE). Methods: BNP levels were measured in patients with acute PE as diagnosed by high probability lung scan or positive spiral computed tomography. All patients underwent standard echocardiography and blood tests during the second hour of the diagnosis. Results: Forty patients diagnosed as acute PE (mean age, 60.4 ± 13.2 years; 62.5% women) were enrolled in this study. Patients with RV dysfunction had significantly higher BNP levels than patients without RV dysfunction (426 ± 299.42 pg/ml vs. 39.09 ± 25.22 pg/ml, p < 0.001). BNP‐discriminated patients with or without RV dysfunction (area under the receiver operating characteristic curve, 0.943; 95% CI, 0.863–1.022). BNP > 90 pg/ml was associated with a risk ratio of 165 (95% CI, 13.7–1987.2) for the diagnosis of RV dysfunction. There was a significant correlation between RV end‐diastolic diameter and BNP (r = 0.89, p < 0.001). Sixteen patients (40%) were diagnosed as having low‐risk PE, 19 patients (47.5%) with submassive PE and five patients (12.5%) with massive PE. The mean BNP was 39.09 ± 25.2, 378.4 ± 288.4 and 609.2 ± 279.2 pg/ml in each group respectively. Conclusion: Measurement of BNP levels may be a useful approach in diagnosis of RV dysfunction in patients with acute PE. The possibility of RV dysfunction in patients with plasma BNP levels > 90 pg/ml should be strongly considered.     

Meta-analysis of controlled trials of ventilator therapy in acute lung injury and acute respiratory distress syndrome: an alternative perspective

Objective The role of protective ventilation in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) is controversial. Evidence was sought from published randomised trials for a consistent treatment effect of protective ventilation and any covariate modification.Design Meta-analysis of protective ventilation trials in ALI/ARDS and meta-regression of covariates on treatment effect (log odds ratio), with respect to 28-day mortality. Heterogeneity impact on the meta-analysis was assessed by the H statistic (substantial impact, >1.5) and graphical analysis. Five trials with a total of 1,202 patients were considered.Measurements and results Average 28-day mortality was 0.40 in the treatment group (protective ventilation, n=605) vs. 0.46 in the control group (control ventilation, n=597). The treatment effect (odds ratio) was: fixed-effects, 0.71 (95% CI 0.56–0.91, p=0.006; heterogeneity, p=0.06) and random effects: 0.80 (95% CI 0.49–1.31, p=0.37). Heterogeneity impact (H statistic=1.50) was adjudged as modest. The treatment effect was significant and (a) favoured protective ventilation for a tidal volume less than 7.7 ml/kg predicted (treatment group) and a mean plateau pressure of 30 cmH₂O or higher (control group) but was not influenced by plateau pressure 21–30 cmH₂O (treatment group) and (b) depended upon plateau pressure difference greater than 5–7 cmH₂O between protective ventilation and standard ventilation.Conclusions Overall treatment effect estimate favoured protective ventilation but did not achieve statistical significance. Protective ventilation depended upon threshold levels of tidal volume, plateau pressure, and plateau pressure difference.Electronic Supplementary Material Electronic supplementary material to this paper can be obtained by using the Springer Link server located at .     

Variation in natriuretic peptides and mitral flow indexes during successful ventilatory weaning: a preliminary study

Objective To assess the cardiac consequences of successful respiratory weaning using the variations of circulating B-type and atrial natriuretic peptides (BNP, ANP) and Doppler mitral flow. Design A prospective preliminary observational study. Setting A 14-bed medical ICU in a French university hospital. Patients Thirty-one patients undergoing a spontaneous breathing trial on a T-tube. Interventions Circulating BNP and ANP levels and Doppler-derived E/A ratio and deceleration time of the E wave were measured before and 1 h after disconnection. Results BNP levels increased from 299 pg/ml (range 56–1079) to 412 pg/ml (147–1324) (p = 0.02) in patients with systolic left ventricular dysfunction, decreased from 98 pg/ml (25–337) to 45 pg/ml (38–180) (p = 0.04) in patients with right ventricular dilation and remained unchanged in patients with neither of these cardiac abnormalities. Overall ANP levels increased from 33 pg/ml to 67 pg/ml (p < 0.001) regardless of ventricular function. The E/A ratio increased from 0.91 (0.66–3.56) to 1.17 (0.5–4.76), (p = 0.01), after disconnection, whereas deceleration time of E wave decreasedfrom 185 ms (120–280) to 160 ms (70–206) (p = 0.02). Conclusion During successful weaning from mechanical ventilation ANP levels increase in all patients whereas changes in BNP levels depend on underlying cardiac function. Changes in Doppler mitral flow indexes following ventilator disconnection suggest an increase in left-ventricular filling pressure. No author has any conflict of interest in this study.     

B-type natriuretic peptide: distribution in the general population and the association with major cardiovascular and coronary events—The Heinz Nixdorf Recall Study

Background

A B-type natriuretic peptide (BNP) threshold of 100 pg/ml is used in practice for identification of heart failure, but data about the “normal” distribution of BNP in a large population in primary prevention are rare. We aimed to characterize the BNP distribution in a healthy subset of a population-based cohort and to evaluate the association of elevated BNP levels with major events.

Methods

In a first step, we determined gender-specific distribution and 90th percentiles of BNP in participants who were at baseline free from known determinants of increased BNP, i.e. cardiovascular disease, hypertension or chronic kidney disease. Consecutively, the association of BNP levels above these 90th percentiles with subsequent cardiovascular and coronary events was assessed in the entire cohort.

Results

In the BNP-normal sub-sample (n = 1,639), we defined gender-specific 90th percentile of BNP (31.3 pg/ml for men, 45.5 pg/ml for women). From overall 3,697 subjects (mean age 59.4, 52.4 % female), 194 subjects developed a major cardiovascular event and 122 myocardial infarction during a mean follow-up period of 8.0 ± 1.5 years. The 90th percentiles derived from the normal subset as threshold showed strong associations with major events in the entire cohort even after adjusting for traditional risk factors: hazard ratio (95 % CI): 1.86 (1.37; 2.53), p < 0.0001 for cardiovascular, and 1.77 (1.19; 2.62), p = 0.005 for coronary events.

Conclusion

The gender-specific 90th percentile of BNP (31 pg/ml for males and 45 pg/ml for females) obtained from a BNP-normal sub-sample is associated with incident major cardiovascular and coronary events, suggesting that even BNP values lower than 100 pg/ml could imply prognostic information in the general population.     

Intérêt du dosage du peptide natriurétique de type-B en médecine d’urgence

Acute dyspnea is frequent in emergency medicine. The B-type natriuretic peptide (BNP) is a polypeptide, released by ventricular myocytes, in direct proportion to wall tension, for lowering renin–angiotensin–aldosterone activation. BNP concentrations closely correlate to heart failure severity. Numerous studies have demonstrated the high usefulness of BNP to diagnose heart failure, which is the main cause of acute dyspnea. The diagnostic accuracy of BNP is higher than that of the emergency physician, and is improved in association with clinical pretest probability. A bedside dosage is now available, with a high sensitivity and specificity for the diagnosis of heart failure. Threshold value is ranging from 80 to 300 pg/ml. Briefly, heart failure is usually absent when BNP is lower than 100 pg/ml, and probably present when BNP is higher than 400 pg/ml.     

Histologic aspects of pulmonary barotrauma in critically ill patients with acute respiratory failure

Objective To describe histologically pulmonary barotrauma in mechanically ventilated patients with severe acute respiratory failure.Design Assessment of histologic pulmonary barotrauma.Setting A 14-bed surgical intensive care unit (SICU).Patients The lungs of 30 young critically ill patients (mean age 34±10 years) were histologically examined in the immediate post-mortem period. None of them were suspected of pre-existing emphysema.Measurements and results Clinical events and ventilatory settings used during mechanical ventilation were compared with lung histology. Airspace enlargement, defined as the presence of either alveolar overdistension in aerated lung areas or intraparenchymal pseudocysts in nonaerated lung areas, was found in 26 of the 30 lungs examined (86%). Patients with severe airspace enlargement (2.6–40 mm internal diameter) had a significantly greater incidence of pneumothorax (8 versus 2,p<0.05), were ventilated using higher peak airway pressures (56±18 cmH₂O versus 44±10 cmH₂O,p<0.05) and tidal volumes (12±3 ml/kg, versus 9±2ml/kg,p<0.05) were exposed significantly longer to toxic levels of oxygen (8.6±9.4 days versus 1.9±2 days at FIO₂>0.6,p<0.05) and lost more weight (6.3±9.2 kg versus 0.75±5.8 kg,p<0.05) than patients with mild airspace enlargement (1–2.5 mm internal diameter).Conclusion Underlying histologic lesions responsible for clinical lung barotrauma consist of pleural cysts, bronchiolar dilatation, alveolar overdistension and intraparenchymal pseudocysts. Mechanical ventilation appears to be an aggravating factor, particularly when high peak airway pressures and large tidal volumes are delivered by the ventilator.Presented in part at the 32ème Congrès de la Société Française d'Anesthésie-Réanimation, Septembre 1990, Paris, France     

New insights into the mechanisms involved in B-type natriuretic peptide elevation and its prognostic value in septic patients

Introduction

Elevated plasma B-type natriuretic peptide (BNP) levels in patients with critical sepsis (severe sepsis and septic shock) may indicate septic cardiomyopathy. However, multiple heterogeneous conditions may also be involved in increased BNP level. In addition, the prognostic value of BNP in sepsis remains debatable. In this study, we sought to discover potential independent determinants of BNP elevation in critical sepsis. The prognostic value of BNP was also evaluated.

Methods

In this observational study, we enrolled mechanically ventilated, critically septic patients requiring hemodynamic monitoring through a pulmonary artery catheter. All clinical, laboratory and survival data were prospectively collected. Plasma BNP concentrations were measured daily for five consecutive days. Septic cardiomyopathy was assessed on day 1 on the basis of left and right ventricular ejection fractions (EF) derived from echocardiography and thermodilution, respectively. Mortality was recorded at day 28.

Results

A total of 42 patients with severe sepsis (N = 12) and septic shock (N = 30) were ultimately enrolled. Daily BNP levels were significantly elevated in septic shock patients compared with those with severe sepsis (P ≤0.002). Critical illness severity (assessed by Acute Physiology and Chronic Health Evaluation II and maximum Sequential Organ Failure Assessment scores), and peak noradrenaline dose on day 1 were independent determinants of BNP elevation (P <0.05). Biventricular EFs were inversely correlated with longitudinal BNP measurements (P <0.05), but not independently. Pulmonary capillary wedge pressures (PCWP) and volume expansion showed no correlation with BNP. In septic shock, increased central venous pressure (CVP) and CVP/PCWP ratio were independently associated with early BNP values (P <0.05).Twenty-eight-day mortality was 47.6% (20 of 42 patients). Daily BNP values poorly predicted outcome; BNP on day 1 > 800 pg/ml (the best cutoff point) fairly predicted mortality, with a sensitivity%, specificity% and area under the curve values of 65, 64 and 0.70, respectively (95% confidence interval = 0.54 to 0.86; P = 0.03). Plasma BNP levels declined faster in survivors than in nonsurvivors in both critical sepsis and septic shock (P ≤0.002). In septic shock, a BNP/CVP ratio >126 pg/mmHg/ml on day 2 and inability to reduce BNP <500 pg/ml implied increased mortality (P ≤0.036).

Conclusions

The severity of critical illness, rather than septic cardiomyopathy, is probably the major determinant of BNP elevation in patients with critical sepsis. Daily BNP values are of limited prognostic value in predicting 28-day mortality; however, fast BNP decline over time and a decrease in BNP <500 pg/ml may imply a favorable outcome.     

Clinical applicability of B-type natriuretic peptide in patients with suspected heart failure in primary care in Spain: the PANAMA study

Aim: To assess the predictive value of B-type natriuretic peptide (BNP) in the diagnosis of heart failure (HF) in a primary-care setting in Spain. Methods: PANAMA was a multicenter and cross-sectional study. Patients ≥18 years of age with a clinical diagnosis of HF (Framingham criteria) were consecutively included in the study by primary-care investigators. BNP determination and an echocardiogram were performed in every patient. The cut-off point of BNP for the criterion of exclusion of HF was considered as <100 pg/ml, as suggested by European guidelines. Sensitivity, specificity, positive-predictive value and negative-predictive value were calculated. Results: A total of 72 patients (mean age: 75.1 ± 8.7 years; 74.6% women) were included. The most frequent associated risk factors were hypertension (75.6%) and dyslipidemia (54.3%). The most common major and minor criteria of HF according to Framingham criteria were radiographic cardiomegaly (90.2%) and dyspnea on ordinary exertion (100%), respectively. BNP median was 49 pg/ml (33.3 pg/ml in those with a doubtful diagnosis of HF and 83.3 pg/ml in those with a likely diagnosis of HF). Approximately 60% of patients exhibited diastolic dysfunction. Concerning accuracy parameters comparing BNP >100 pg/ml with echocardiogram, sensitivity was 25%, the specificity 80.8%, and the positive- and negative-predictive values were 68.8 and 38.9%, respectively. Conclusion: In patients attended by general practitioners, BNP >100 pg/ml may be a useful diagnostic tool with a high specificity for the diagnosis of HF.     

Prediction equation estimates of creatinine clearance in the intensive care unit

Objective To assess the accuracy of 4 mathematical equations used to estimate creatinine clearance versus the 24-h creatinine clearance in ICU patients.Design Prospective study of renal function prediction.Setting The general adult ICUs of 3 metropolitan hospitals.Patients 199 critically ill patients with indwelling foley catheters.Intervention and measurements Routine 24 h creatinine clearances were evaluated only in patients whose urine volume recorded by the nurses was within 10% of the laboratory's measured volume. Four mathematical equations utilizing age, sex, body weight, height, and plasma creatinine were used as a comparison. There was no difference in estimated creatinine clearance by 3 published methods when the 24 h creatinine clearance exceeded 100 ml/min. When the 24 h creatinine clearance was less than 100 ml/min, however, one prediction equation adjusted for lean body weight (LBW), was the most accurate. This equation accurately predicted creatinine clearance in the range of 30–100 ml/min and slightly overestimated creatinine clearance at 0–30 ml/min (p<0.01, ANOVA all groups,p<0.05 Fisher and Scheffé post-hoc tests) with a mean difference ±95% confidence interval of –5±3.1 ml/min.Conclusion An initial rapid estimate of creatinine clearance in critically ill ICU patients with reduced renal function can be determined by an equation adjusted for LBW.     

N-terminal pro brain natriuretic peptide reflects long-term complications in type 1 diabetes

Abstract

Purpose. To evaluate N-terminal pro brain natriuretic peptide (NT-proBNP) as a marker of long-term micro- and macrovascular complications in type 1 diabetes. Methods. This was a cross-sectional study of 208 long-term surviving type 1 diabetic patients from a population-based cohort from Fyn County, Denmark. In a clinical examination in 2007–2008, NT-proBNP was measured and related to proliferative diabetic retinopathy (PDR), nephropathy, neuropathy and macrovascular disease. Results. Median age and duration of diabetes was 58.7 and 43 years, respectively. Median NT-proBNP concentration was 78 pg/ml (10th–90th percentile 25–653 pg/ml). The NT-proBNP level (89 vs. 71 pg/ml, p = 0.02) was higher in women. In univariate analyses, NT-proBNP was associated with age, duration of diabetes, diastolic blood pressure (inversely), nephropathy, neuropathy and macrovascular disease. For instance, median NT-proBNP concentrations were 70, 91 and 486 pg/ml for patients with normo-, micro- and macroalbuminuria, respectively (p < 0.01). When adjusted for age, sex, duration of diabetes, high sensitivity CRP, HbA_1c, diastolic blood pressure and smoking, higher NT-proBNP concentrations (4th vs. 1st quartile) were related to nephropathy (odds ratio [OR] 5.03; 95% confidence interval [CI] 1.77–14.25), neuropathy (OR 4.08; 95% CI 1.52–10.97) and macrovascular disease (OR 5.84; 95% CI 1.65–20.74). There was no association with PDR. Conclusions. NT-proBNP has traditionally been described as a marker of heart failure and left ventricular dysfunction. In this study of long-term surviving type 1 diabetic patients, we found NT-proBNP associated with nephropathy, neuropathy and macrovascular disease. If confirmed by prospective studies, NT-proBNP might be a useful prognostic marker of diabetes-related complications.     

BNP对ICU急性呼吸衰竭的诊断价值与右心导管的对比研究

目的:探讨血脑利钠肽(BNP)对急性呼吸窘迫综合征(ARDS)及心源性肺水肿(CPE)的诊断价值。方法:34例行右心导管检查(RHC)的严重急性呼吸衰竭患者,测量其BNP浓度、胸片、呼吸机参数及血流动力学参数等数据。并参考肺动脉楔压(PCWP)鉴别诊断ARDS及CPE;统计相应的BNP浓度,获取理想的诊断截点。结果:与CPE组患者相比,ARDS患者具有较高的PEEP以及低的右房压力(RAP)和PCWP,两组比较差异有统计学意义(P=0.012、0.023及0.031)。ARDS患者的BNP显著低于CPE患者(355±168pg/ml和1550±250pg/ml,P=0.001)。BNP与PCWP正相关(r=0.34,P=0.031)。当BNP截点为200pg/ml时,BNP诊断ARDS的特异性为93%,阳性预测值为90%;当BNP截点为1200pg/ml时,BNP诊断CPE的特异性为93%,阳性预测值为78%。结论:BNP结合临床资料能很好地鉴别ICU病房中的ARDS和CPE,具有较高的临床应用价值。     

Gated blood pool SPECT for measurement of left ventricular volumes and left ventricular ejection fraction: comparison of 8 and 16 frame gated blood pool SPECT

Gated blood pool SPECT (GBPS) is an alternative to planar radionuclide ventriculography (PRNV) and offers potential advantages. The aim of this study was to compare 8 and 16 frame GBPS for the determination of left ventricular ejection fraction(LVEF) and left ventricular volumes (LV) in subjects underwent two consecutive GBPS. Method: About 66 consecutive patients (30 men, 36 women; mean age 62.3 ± 10.4 years) referred for PRNV for evaluation of preoperative cardiac risk stratification (n=40), prechemotherapy cardiac function evaluation (n=18, breast cancer), and congestive heart failure patients (n=8). All patients underwent PRNV of 16 frame and GBPS with both of 8 and 16 frame. Results: The mean LVEF calculated with PRNV (58.3 ± 16.8), showed statistically lower than 8-GBPS (70.6 ± 17.7), and 16-GBPS (69.9 ± 16.8) (PRNV vs. 8-GBPS, p < 0.01; PRNV vs 16-GBPS, p < 0.01; 8-GBPS vs 16-GBPS, p > 0.05). The correlation of LVEFS between 8-GBPS and 16-GBPS showed a correlation coefficient of 0.9194 (p < 0.01, 95% CI=0.8712–0.9500). The mean left ventricular end-diastolic volumes (EDV) calculated with 8-GBPS (83.2 ± 33.5 ml), and 16-GBPS (88.4 ± 36.8 ml) showed no statistical differences (p > 0.05). The mean left ventricular end-systolic volumes (ESV) calculated with 8-GBPS (28.1 ± 31.4 ml), and 16-GBPS (30.5 ± 33 ml) showed also no statistical differences (p > 0.05). Comparison of EDV from 8 and 16-GBPS yielded a correlation coefficient of 0.7430 (p < 0.01, 95% CI=0.6108-0.8349). The correlation between ESV of 8-GBPS and 16-GBPS showed a correlation coefficient of 0.9522 (p < 0.01, 95% CI=0.9228–0.9705). Conclusion: This study demonstrated that the LVEFs of 8-GBPS correlated well with that of 16-GBPS. The LVEF of PRNV was significantly lower than those of 8 and 16-GBPS. Also, left ventricular EDV and ESV of 8-GBPS correlated well with those of 16-GBPS. Also, further studies, involving large lumber patients, should be performed to validate the usefulness of GBPS for the evaluation of left ventricular diastolic function.     

Prostacyclin and right ventricular function in patients with pulmonary hypertension associated with ARDS

Eight patients who developed pulmonary artery hypertension during the adult respiratory distress syndrome (ARDS) were treated with an infusion of prostacyclin (PGI₂, 12.5–35.0 ng·kg^–1·min^–1) for 45 min. We examined whether reducing the right ventricular (RV) outflow pressures by PGI₂ infusion would increase the right ventricular ejection fraction (RVEF) measured by thermodilution. PGI₂ reduced the pulmonary artery pressure (PAP) from 35.6 to 29.1 mmHg (p<0.01). The cardiac index (CI) increased from 4.2 to 5.81·min^–1·m^–2 (p<0.01) partly due to an increased stroke volume. The decreased PAP together with the increased CI resulted in a fall of the calculated pulmonary vascular resistance index (PVRI, from 5.1 to 2.5 mmHg·min·m²·1^–1,p<0.01). In the patients with subnormal baseline RVEF the increased stroke volume was associated with an increased RVEF (from 47.6% to 51.8%,p<0.05) suggesting improved RV function. This result was underscored by a significant relationship between the changes in PVRI and RVEF (r=0.789, % RVEF=–2.11·PVRI-1.45). Despite an increased venous admixture from 27.8% to 36.9% (p<0.05) the arterial PO₂ remained constant resulting in an increased oxygen delivery from 657 to 894 ml·min^–1·m^–2 (p<0.01). We conclude that short term infusions of PGI₂ increased CI concomitant to improved RV function parameters when baseline RVEF was depressed. Since improved oxygen availability should be a major goal in the management of patients with ARDS PGI₂ may be useful to lower pulmonary artery pressure in ARDS.Supported by the Deutsche Forschungsgemeinschaft (grant Fa 139/2-2)