Can transcutaneous carbon dioxide pressure be a surrogate of blood gas samples for spontaneously breathing emergency patients? The ERNESTO experience.

BACKGROUND: It is known that the arterial carbon dioxide pressure (PaCO2) is useful for emergency physicians to assess the severity of dyspnoeic spontaneously breathing patients. Transcutaneous carbon dioxide pressure (PtcCO2) measurements could be a non-invasive alternative to PaCO2 measurements obtained by blood gas samples, as suggested in previous studies. This study evaluates the reliability of a new device in the emergency department (ED). METHODS: We prospectively included patients presenting to the ED with respiratory distress who were breathing spontaneously or under non-invasive ventilation. We simultaneously performed arterial blood gas measurements and measurement of PtcCO2 using a sensor placed either on the forearm or the side of the chest and connected to the TCM4 CombiM device. The agreement between PaCO2 and PtcCO2 was assessed using the Bland-Altman method. RESULTS: Sixty-seven spontaneously breathing patients were prospectively included (mean age 70 years, 52% men) and 64 first measurements of PtcCO2 (out of 67) were analysed out of the 97 performed. Nineteen patients (28%) had pneumonia, 19 (28%) had acute heart failure and 19 (28%) had an exacerbation of chronic obstructive pulmonary disease. Mean PaCO2 was 49 mm Hg (range 22-103). The mean difference between PaCO2 and PtcCO2 was 9 mm Hg (range -47 to +54) with 95% limits of agreement of -21.8 mm Hg and 39.7 mm Hg. Only 36.3% of the measurement differences were within 5 mm Hg. CONCLUSIONS: Our results show that PtcCO2 measured by the TCM4 device could not replace PaCO2 obtained by arterial blood gas analysis.

Risk factors for onset of hypothermia in trauma victims: the HypoTraum study.

INTRODUCTION: Hypothermia is common in trauma victims and is associated with an increase in mortality. Its causes are not well understood. Our objective was to identify the factors influencing the onset of hypothermia during pre-hospital care of trauma victims. METHODS: This was a multicenter, prospective, open, observational study in a pre-hospital setting. RESULTS: A total of 448 patients were included. Hypothermia (<35 °C) on hospital arrival was present in 64/448 patients (14%). Significant factors associated with the absence of hypothermia in a multivariate analysis were no intubation: Odds Ratio: 4.23 (95% confidence interval 1.62 to 1.02); RTS: 1.68 (1.29 to 2.20); mobile unit temperature: 1.20 (1.04 to 1.38); infusion fluid temperature: 1.17 (1.05 to 1.30); patient not unclothed: 0.40 (0.18 to 0.90); and no head injury: 0.36 (0.16 to 0.83). CONCLUSIONS: The key risk factor for the onset of hypothermia was the severity of injury but environmental conditions and the medical care provided by EMS were also significant factors. Changes in practice could help reduce the impact of factors such as infusion fluid temperature and mobile unit temperature.

Prognostic value of PCT in septic emergency patients.

BACKGROUND: An accurate assessment of septic patients at risk for poor clinical outcomes is challenging for clinicians in the emergency department (ED). OBJECTIVES: We aimed to evaluate the prognostic value of procalcitonin (PCT) in septic patients in the ED for predicting death. RESULTS: In a retrospective study, 188 septic patients (median age 63 [IQR 51-80]) of two French university hospitals were included. Patients who deceased within 30 days (20 %, n = 37) presented higher PCT value at admission (median 34.0 µg/L [5.0-71.9]) in comparison with the survivals (median 6.4 µg/L [4.1-13.1], p = 0.0005). ROC curve analysis indicated a moderate AUC of 0.686 [95 % CI 0.613-0.752] and an optimal PCT threshold value at 32.5 [95 % CI 21.8-43.3] µg/L that was associated with a 51 % [34-67] sensitivity, a 96 % [90-98] specificity, a 73 % [52-88] positive predictive value, and a 89 % [83-93] negative predictive value for death. Only 26 patients (14 %) had PCT values above this threshold (19 in the deceased group vs 7 in survival group, p < 0.0001). By multivariate analysis, only three variables remained significantly predictive of the death: personal history of cardiovascular disease (OR 3.1 [1.0-9.4], p = 0.046), the presence of severe sepsis/septic shock in the ER (OR 4.4 [1.3-12.3], p = 0.013), and a PCT level >32.5 µg/L (OR 36.0 [10.0-128.4], p < 0.0001). Similar results were obtained when considering the combined outcome death and/or admission in ICU. CONCLUSION: Elevated value of PCT at admission has moderate accuracy to identify poor outcome in ED septic patients in daily practice.