Unique blood culture for diagnosis of bloodstream infections in emergency departments: a prospective multicentre study.

Detection of microorganisms by blood cultures (BCs) is essential in managing patients with bacteraemia. Rather than the number of punctures, the volume of blood drawn is considered paramount in efficient and reliable detection of microorganisms. We performed a 1-year prospective multicentre study in adult emergency departments of three French university hospitals comparing two methods for BCs: a unique blood culture (UBC) collecting a large volume of blood (40 mL) and the standard method of multiple blood cultures (MBC). The performances of both methods for bacterial contamination and efficient microbial detection were compared, each patient serving as his own control. Amongst the 2314 patients included, three hundred were positive for pathogens (n=245) or contaminants (n=55). Out of the 245 patients, 11 were positive for pathogens by UBC but negative by MBC and seven negative by UBC but positive by MBC (p 0.480). In the subgroup of 137 patients with only two BCs, UBC was superior to MBC (p 0.044). Seven and 17 patients had contaminated BCs by UBC and MBC only, respectively (p 0.062). Considering the sums of pathogens missed and contaminants, UBC significantly outperformed MBC (p 0.045). Considering the complete picture of cost savings, efficient detection of microorganisms and decrease in contaminations, UBC offers an interesting alternative to MBC.

Accuracy of a transcutaneous carbon dioxide pressure monitoring device in emergency room patients with acute respiratory failure.

PURPOSE: Transcutaneous CO(2) monitors are widely used in neonatal ICUs. Until recently, these devices performed poorly in adults. Recent technical modifications have produced transcutaneous CO(2) monitors that have performed well in adults with chronic illnesses. We evaluated the accuracy of one of these devices, the TOSCA(®) 500, in adults admitted to an emergency department for acute respiratory failure. METHODS: We prospectively collected 29 pairs of simultaneous transcutaneous arterial CO(2) (PtcCO(2)) and arterial CO(2) (PaCO(2)) values in 21 consecutive adults with acute respiratory failure (acute heart failure, n = 6; COPD exacerbation, n = 8; acute pneumonia, n = 6; and pulmonary embolism, n = 1). Agreement between PaCO(2) and PtcCO(2) was evaluated using the Bland-Altman method. RESULTS: Mean arterial oxygen saturation was 90%, arterial oxygen tension ranged from 32 to 215 mmHg, and PaCO(2) ranged from 23 to 84 mmHg. The mean difference between PaCO(2) and PtcCO(2) was 0.1 mmHg, and the Bland-Altman limits of agreement (bias ± 1.96 SD) ranged from -6 to 6.2 mmHg. None of the patients experienced adverse effects from heating of the device clipped to the earlobe. CONCLUSION: PtcCO(2) showed good agreement with PaCO(2) in adults with acute respiratory failure.