A single procalcitonin level does not predict adverse outcomes of women with pyelonephritis.

OBJECTIVES: Predicting medical outcomes for pyelonephritis in women is difficult, leading to unnecessary hospitalization. Unlike other serious infectious diseases, high procalcitonin (PCT) level has never been associated with 28-d adverse medical outcomes in women with pyelonephritis. Therefore, we sought to determine the accuracy of PCT in discriminating between pyelonephritis with adverse medical outcome (PAMO) and pyelonephritis without adverse medical outcome (PWAMO). PATIENTS AND METHODS: Adult women with pyelonephritis presenting to the emergency department of a French tertiary care hospital were consecutively included. Those patients who developed adverse medical outcomes during a 28-d follow-up period were identified as having PAMO. Baseline characteristics and PCT level were compared between patients with PAMO and PWAMO. RESULTS: Eleven women (19.0%) had PAMO and 47 (81%) had PWAMO. The median PCT level was higher in PAMO compared with PWAMO 0.51 ng/ml (IQR: 0.04-3.8) and 0.08 ng/ml (IQR: 0.01-1.0), but this difference was not statistically significant (p=0.07). We failed to find a threshold value for PCT that discriminated between PAMO and PWAMO (ROC, AUC=0.67 [95%CI, 0.51-0.86]). All but one subject with PAMO had either a PCT level >0.1 ng/ml or an underlying genitourinary abnormality by radiographic testing. CONCLUSIONS: A single PCT level was a poor predictor of 28-d adverse medical outcomes in women with pyelonephritis treated in the emergency department. Prediction based on underlying genitourinary abnormality by radiographic testing in addition to the PCT level should be investigated in future studies.

B-type natriuretic peptide and weaning from mechanical ventilation.

OBJECTIVE: Cardiac function and volume status could play a critical role in the setting of weaning failure. B-type natriuretic peptide (BNP) is a powerful marker of cardiac dysfunction. We assessed the value of BNP during the weaning process. DESIGN, SETTING AND PATIENTS: One hundred and two consecutive patients considered ready to undergo a 1-h weaning trial (T-piece or low-pressure support level) were prospectively included in a medical intensive care unit of a university hospital. Weaning was considered successful if the patient passed the trial and sustained spontaneous breathing for more than 48 h after extubation. INTERVENTIONS: Plasma BNP was measured just before the trial in all patients, and at the end of the trial in the first 60 patients. RESULTS: Overall, 42 patients (41.2%) failed the weaning process (37 patients failed the trial and 5 failed extubation). Logistic regression analysis identified high BNP level before the trial and the product of airway pressure and breathing frequency during ventilation as independent risk factors for weaning failure. BNP values were not different at the end of the trial. In nine of the patients in whom the weaning process failed, it succeeded on a later occasion after diuretic therapy. Their BNP level before weaning decreased between the two attempts (517 vs 226 pg/ml, p=0.01). In survivors, BNP level was significantly correlated to weaning duration (rho=0.52, p<0.01). CONCLUSIONS: Baseline plasma BNP level before the first weaning attempt is higher in patients with subsequent weaning failure and correlates to weaning duration.

Usefulness of plasma B-type natriuretic peptide in predicting recurrence of atrial fibrillation one year after external cardioversion.

After successful external cardioversion, the rate of recurrence of atrial fibrillation remains high. The hypothesis that plasma B-type natriuretic peptide could predict the recurrence of atrial fibrillation at 1 year was tested. Plasma B-type natriuretic peptide was measured in 66 consecutive asymptomatic patients who underwent external cardioversion for atrial fibrillation. Twelve-lead electrocardiograms were obtained at 1 year. Sinus rhythm was maintained in 55% of patients. The independent predictors of the recurrence of atrial fibrillation at 1 year were a history of atrial fibrillation, plasma B-type natriuretic peptide, and the energy delivered for conversion. In patients without symptoms of heart failure, plasma B-type natriuretic peptide is an independent predictor of the recurrence of atrial fibrillation.

Performance of a revised cardiac troponin method that minimizes interferences from heterophilic antibodies.

BACKGROUND: Recent guidelines for use of cardiac troponin to detect cardiac damage and for cardiovascular risk stratification have made increasingly sensitive troponin assays important. Troponin assays continue to be plagued by interferences caused by heterophilic antibodies (HAs). We evaluated the performance of a revised cardiac troponin I (cTnI) assay designed to have increased analytical sensitivity and to minimize the effect of HAs. METHODS: The revised Dade Behring Dimension cTnI assay was evaluated according to NCCLS EP5-A at five institutions. Plasma samples from 14 309 patients were assayed by the original Dimension cTnI assay. To identify samples that may have interfering HAs, samples with values >1.4 microg/L were reanalyzed on the Dade Behring Stratus CS cTnI assay. Samples with possible interfering antibodies were also analyzed before and after selective absorbance studies on the revised Dade Behring Dimension cTnI assay. RESULTS: The limit of quantification in the revised method was 0.1 microg/L with imprecision (CV) of 11-17% at 0.1 microg/L. Values correlated well with the Stratus CS cTnI method: revised = 1.06(original) + 0.01; r = 0.98, S(y/x) = 0.25 microg/L). Falsely increased results consistent with myocardial infarction by the original Dimension cTnI assay and presumably attributable to HAs were identified in 0.17% of all patients with samples submitted for cTnI analysis. The revised Dimension cTnI assay eliminated the interference in 17 of 25 samples identified and greatly decreased the interference in the other 8. CONCLUSIONS: The revised Dimension cTnI method greatly minimizes the effect of interfering HAs. It also exhibits analytical performance characteristics consistent with recent guidelines for use of this assay to detect cardiac damage.