Precision of noninvasive hemoglobin-level measurement by pulse co-oximetry in patients admitted to intensive care units for severe gastrointestinal bleeds.

OBJECTIVES: Measurement of total hemoglobin, based on pulse co-oximetry, is a continuous and noninvasive method that has been principally evaluated in healthy volunteers subjected to hemodilution. We tested the hypothesis that its accuracy could adversely affect patients presenting with severe hemorrhage, which is traditionally associated with increased microvascular tone. DESIGN: Observational study. SETTING: Twelve-bed mixed medico-surgical intensive care unit. PATIENTS: Thirty-three patients admitted to our critical care unit for gastrointestinal bleeds were included. INTERVENTIONS: A spectrophotometric sensor was positioned on the patient's fingertip and connected to a pulse co-oximeter. During the first 24 hrs following admission, venous hemoglobin level was determined at the laboratory every 8 hrs and was compared with hemoglobin levels displayed on the pulse co-oximeter measurements screen and/or measured from capillary blood using a portable photometer. MEASUREMENTS AND MAIN RESULTS: The primary end point was the percentage of inaccurate measurements, which were defined as >15% difference compared with reference values or their unavailability for any technical reason. Twenty-five (19%) measurements of pulse co-oximeter measurements were unavailable from the screen. Pulse co-oximeter measurements and capillary hemoglobin levels were significantly correlated to venous hemoglobin level. For venous hemoglobin level compared with pulse co-oximeter measurements (n = 105), and for venous hemoglobin level compared with capillary hemoglobin levels (n = 111), the biases were, respectively, 1.0 ± 1.9 g dL and 0.4 ± 1.0 g dL (p < .05). The proportion of inaccurate measurements was significantly higher for pulse co-oximeter measurements (56% vs. 15%, p < .05). Although the use of norepinephrine did not affect concordance parameters, unavailability of measurements was frequently observed (42% vs. 15%, p < .05). CONCLUSIONS: Determination of pulse co-oximetry-based hemoglobin in patients presenting with severe gastrointestinal bleeds can be inaccurate, which renders its use to guide transfusion decisions potentially hazardous. The unavailability of measurements, especially during vasopressor infusion, represents another serious limitation for hemorrhagic patients.

The sustainable impact of an educational approach to improve the appropriateness of laboratory test orders in the ICU.

INTRODUCTION: Few studies described strategies to improve the use of diagnostic tests in intensive care units (ICU). No study assessed whether their impact was sustained or not. In this study, we assessed whether a multi-faceted intervention for more appropriate use of laboratory testing can decrease the number of tests, is sustainable, is not associated with additional morbidity and represents a potential cost saving. MATERIAL AND METHODS: An open-label prospective cohort study in two separated units of the same medical intensive care unit (ICU) including respectively 3315 and 2392 consecutive patients. After the observation period (2010), a reduction in ICU A of unnecessary diagnostics tests as part of a program including senior supervisory of juniors' orders, encouragements for orders containment at each everyday round discussions (period 2; 2011). Period 3 (2012) consisted in the prolongation of the protocol as a routine care without supervision; Period 4 (2013) was a new period of observation without intervention. No modification was implemented in ICU B in periods 2-4. RESULTS: After the intervention, a decrease in the overall number of tests per ICU-patient-days (37.3±5.5 (baseline) to 15.2±3.2 (- 59%); p<0.0001) was observed. The total cost of the tests decreased from 239±41 to 104±28 euros per ICU-patient days; p<0.0001. The effect on laboratory test orders was sustainable in period 3 (-49%) and 4 (-30%). No significant secondary effect of the intervention was observed in period 2. In ICU B, there was no significant change in the overall laboratory test orders in between the periods. CONCLUSIONS: Laboratory test containment is effective, likely safe and sustainable provided that an educational program is repeatedly promoted, that it makes sense for the whole team, that senior and junior physicians are both committed in the program, and that encouragements for laboratory orders containment at each everyday round discussions.

Determinants and prognosis of high-sensitivity cardiac troponin T peak plasma concentration in patients hospitalized for non-cardiogenic shock.

PURPOSE: The aim of this study was to assess the determinants and prognostic value of high-sensitivity cardiac troponin T peak plasma concentration in intensive care unit patients with non-cardiogenic shock. MATERIAL AND METHODS: A prospective observational cohort study was conducted in a single intensive care unit between November 2014 and December 2015. RESULTS: During the study period, 206 patients were hospitalized in the intensive care unit for non-cardiogenic shock and the median peak high-sensitivity cardiac troponin T was 55.1 [24.5-136] pg/mL. A multivariate analysis combining all variables showed that higher body mass index (t = 2.52, P = 0.01), lower left ventricular systolic function (t = -2.73, P = 0.007), higher white blood cell count (t = 3.72, P = 0.0001), lower creatinine clearance (t = -2.84, P = 0.0005), higher lactate level (t = 2.62, P = 0.01) and ST-segment depression (t = 3.98, P = 0.0001) best correlated with log10-transformed high-sensitivity cardiac troponin T peak plasma concentration. After multivariate analysis, the high-sensitivity cardiac troponin T peak was not associated with a significant reduction of in-hospital mortality (adjusted odds ratio = 0.99 (95% confidence interval: 0.93-1.02)). CONCLUSION: High-sensitivity cardiac troponin T elevation was very common in patients hospitalized for non-cardiogenic shock. The factors significantly associated with high-sensitivity cardiac troponin T peak plasma concentration were higher body mass index, decreased left ventricular systolic ejection fraction, higher leucocyte count, decreased renal function, increased lactate level, and ST-segment depression. The high-sensitivity cardiac troponin T peak was not significantly associated with in-hospital mortality in this setting.

Assessment of the National French recommendations regarding the dosing regimen of 8mg/kg of gentamicin in patients hospitalised in intensive care units.

INTRODUCTION: To assess the French National Agency for Medicines and Health Products Safety (ANSM) guidelines concerning the peak plasma concentration (Cmax) of gentamicin when using a loading dose of 8mg/kg administered in patients hospitalised in the intensive care unit (ICU). PATIENTS AND METHODS: A prospective observational cohort study conducted in one ICU. RESULTS: During the study period, 34 patients with a median simplified acute physiology score 2 of 54 [44-70] received a median dose of 8 [7.9-8.1] mg/kg of gentamicin. The median Cmax was 17.5 [15.4-20.7] mg/L and no patient had a Cmax>30mg/L. Twenty-four of 34 patients (71%) had a Cmax>16mg/L. Following multivariate analysis, the only factor associated with Cmax<16mg/L was a positive fluid balance 24hours before gentamicin administration (per 1000mL increment) (OR: 0.37, 95% CI: 0.18-0.77, P=0.008). CONCLUSIONS: These results suggest that a Cmax>30mg/L [which corresponds to approximately 8 times the minimal inhibiting concentrations (MIC) breakpoints for Pseudomonas aeruginosa and Enterobacteriaceae with intermediate sensitivity] of gentamicin as recommended by ANSM guidelines seems impossible to obtain with a loading dose of 8mg/kg in the ICU. A loading dose of 8mg/kg should probably not be used in the empiric antibiotic treatment of infection due to non-fermenting Gram-negative bacilli and Enterobacteriaceae with intermediate sensitivity whose MIC breakpoint is 4mg/L. A Cmax>16mg/L was not reached in almost 30% of patients, particularly in the group with a positive fluid balance who require higher doses than currently recommended.