Combination of lung ultrasound (a comet-tail sign) and N-terminal pro-brain natriuretic peptide in differentiating acute heart failure from chronic obstructive pulmonary disease and asthma as cause of acute dyspnea in prehospital emergency setting.

INTRODUCTION: We studied the diagnostic accuracy of bedside lung ultrasound (the presence of a comet-tail sign), N-terminal pro-brain natriuretic peptide (NT-proBNP) and clinical assessment (according to the modified Boston criteria) in differentiating heart failure (HF)-related acute dyspnea from pulmonary (chronic obstructive pulmonary disease (COPD)/asthma)-related acute dyspnea in the prehospital setting. METHODS: Our prospective study was performed at the Center for Emergency Medicine, Maribor, Slovenia, between July 2007 and April 2010. Two groups of patients were compared: a HF-related acute dyspnea group (n = 129) and a pulmonary (asthma/COPD)-related acute dyspnea group (n = 89). All patients underwent lung ultrasound examinations, along with basic laboratory testing, rapid NT-proBNP testing and chest X-rays. RESULTS: The ultrasound comet-tail sign has 100% sensitivity, 95% specificity, 100% negative predictive value (NPV) and 96% positive predictive value (PPV) for the diagnosis of HF. NT-proBNP (cutoff point 1,000 pg/mL) has 92% sensitivity, 89% specificity, 86% NPV and 90% PPV. The Boston modified criteria have 85% sensitivity, 86% specificity, 80% NPV and 90% PPV. In comparing the three methods, we found significant differences between ultrasound sign and (1) NT-proBNP (P < 0.05) and (2) Boston modified criteria (P < 0.05). The combination of ultrasound sign and NT-proBNP has 100% sensitivity, 100% specificity, 100% NPV and 100% PPV. With the use of ultrasound, we can exclude HF in patients with pulmonary-related dyspnea who have positive NT-proBNP (> 1,000 pg/mL) and a history of HF. CONCLUSIONS: An ultrasound comet-tail sign alone or in combination with NT-proBNP has high diagnostic accuracy in differentiating acute HF-related from COPD/asthma-related causes of acute dyspnea in the prehospital emergency setting. TRIAL REGISTRATION: ClinicalTrials.gov NCT01235182.

Combination of quantitative capnometry, N-terminal pro-brain natriuretic peptide, and clinical assessment in differentiating acute heart failure from pulmonary disease as cause of acute dyspnea in pre-hospital emergency setting: study of diagnostic accuracy.

AIM: To determine the diagnostic accuracy of the combination of quantitative capnometry (QC), N-terminal pro-brain natriuretic peptide (NT-proBNP), and clinical assessment in differentiating heart failure (HF)-related acute dyspnea from pulmonary-related acute dyspnea in a pre-hospital setting. METHODS: This prospective study was performed in the Center for Emergency Medicine Maribor, Slovenia, January 2005-June 2007. Two groups of patients with acute dyspnea apnea were compared: HF-related acute dyspnea group (n = 238) vs pulmonary-related acute dyspnea (asthma/COPD) group (n = 203). The primary outcome was the comparison of combination of QC, NT-proBNP, and clinical assessment vs NT-proBNP alone or NT-proBNP in combination with clinical assessment, in differentiating HF-related acute dyspnea from pulmonary-related acute dyspnea (asthma/COPD) in pre-hospital emergency setting, using the area under the receiver operating characteristic curve (AUROC). The secondary outcomes end points were identification of independent predictors for final diagnosis of acute dyspnea (caused by acute HF or pulmonary diseases), and determination of NT-proBNP levels, as well as capnometry, in the subgroup of patients with a previous history of HF and in the subgroup of patients with a previous history of pulmonary disease. RESULTS: In differentiating between cardiac and respiratory causes of acute dyspnea in pre-hospital emergency setting, NT-proBNP in combination with PetCO2 and clinical assessment (AUROC, 0.97; 95% confidence interval [CI], 0.90-0.99) was superior to combination of NT-proBNP and clinical assessment (AUROC, 0.94; 95% CI, 0.88-0.96; P = 0.006) or NT-proBNP alone (AUROC, 0.90; 95% CI, 0.85-0.94; P = 0.005). The values of NT-proBNP> or = 2000 pg/mL and PetCO2 < or = 4 kPa were strong independent predictors for acute HF. In the group of acute HF dyspneic patients, subgroup of patients with previous COPD/asthma had significantly higher PetCO2 (3.8 +/- 1.2 vs 5.8 +/- 1.3 kPa, P = 0.009). In the group of COPD/asthma dyspneic patients, NT-proBNP was significantly higher in the subgroup of patients with previous HF (1453.3 +/- 552.3 vs 741.5 +/- 435.5 pg/mL, P = 0.010). CONCLUSION: In differentiating between cardiac and respiratory causes of acute dyspnea in pre-hospital emergency setting, NT-proBNP in combination with capnometry and clinical assessment was superior to NT-proBNP alone or NT-proBNP in combination with clinical assessment.

Partial pressure of end-tidal carbon dioxide successful predicts cardiopulmonary resuscitation in the field: a prospective observational study.

INTRODUCTION: Prognosis in patients suffering out-of-hospital cardiac arrest is poor. Higher survival rates have been observed only in patients with ventricular fibrillation who were fortunate enough to have basic and advanced life support initiated soon after cardiac arrest. An ability to predict cardiac arrest outcomes would be useful for resuscitation. Changes in expired end-tidal carbon dioxide levels during cardiopulmonary resuscitation (CPR) may be a useful, noninvasive predictor of successful resuscitation and survival from cardiac arrest, and could help in determining when to cease CPR efforts. METHODS: This is a prospective, observational study of 737 cases of out-of-hospital cardiac arrest. The patients were intubated and measurements of end-tidal carbon dioxide taken. Data according to the Utstein criteria, demographic information, medical data, and partial pressure of end-tidal carbon dioxide (PetCO2) values were collected for each patient in cardiac arrest by the emergency physician. We hypothesized that an end-tidal carbon dioxide level of 1.9 kPa (14.3 mmHg) or more after 20 minutes of standard advanced cardiac life support would predict restoration of spontaneous circulation (ROSC). RESULTS: PetCO2 after 20 minutes of advanced life support averaged 0.92 +/- 0.29 kPa (6.9 +/- 2.2 mmHg) in patients who did not have ROSC and 4.36 +/- 1.11 kPa (32.8 +/- 9.1 mmHg) in those who did (P < 0.001). End-tidal carbon dioxide values of 1.9 kPa (14.3 mmHg) or less discriminated between the 402 patients with ROSC and 335 patients without. When a 20-minute end-tidal carbon dioxide value of 1.9 kPa (14.3 mmHg) or less was used as a screening test to predict ROSC, the sensitivity, specificity, positive predictive value, and negative predictive value were all 100%. CONCLUSIONS: End-tidal carbon dioxide levels of more than 1.9 kPa (14.3 mmHg) after 20 minutes may be used to predict ROSC with accuracy. End-tidal carbon dioxide levels should be monitored during CPR and considered a useful prognostic value for determining the outcome of resuscitative efforts and when to cease CPR in the field.

Glasgow Coma Scale score and QTc interval in the prognosis of organophosphate poisoning.

OBJECTIVES: The aim of this study was to assess the applicability of the Glasgow Coma Scale (GCS) score and the Q-T interval corrected for heart rate (QTc interval) in predicting outcome and complications in patients with organophosphate (OP) poisoning. METHODS: This prospective, observational study included 65 patients older than 18 years. In the out-of-hospital setting, the end-tidal carbon dioxide (ETCO2), oxygen saturation (SaO2), QTc interval, and GCS score were monitored in each patient. A statistical comparison was then made between the group with respiratory failure and the group without this complication. RESULTS: The group with complications had significantly different values of measured parameters--a longer QTc interval and a lower GCS score, a higher number of intubations, and worse outcomes (p < 0.05). The two measures, GCS score and QTc interval, have been shown to be equally good in predicting respiratory failure and hospital mortality in patients with OP poisoning. CONCLUSIONS: In the initial out-of-hospital care of patients with OP poisoning, it is essential to monitor QTc interval and GCS score. These measures help with prognosis, and may suggest when to initiate precautions to prevent complications (i.e., respiratory failure). The simplicity and promptness of these methods allow providers to perform early and effective triage.