Intra-patient potassium variability after hypothermic cardiac arrest: a multicentre, prospective study.

To date, the decision to set up therapeutic extra-corporeal life support (ECLS) in hypothermia-related cardiac arrest is based on the potassium value only. However, no information is available about how the analysis should be performed. Our goal was to compare intra-individual variation in serum potassium values depending on the sampling site and analytical technique in hypothermia-related cardiac arrests. Adult patients with suspected hypothermia-related refractory cardiac arrest, admitted to three hospitals with ECLS facilities were included. Blood samples were obtained from the femoral vein, a peripheral vein and the femoral artery. Serum potassium was analysed using blood gas (BGA) and clinical laboratory analysis (CL). Of the 15 consecutive patients included, 12 met the principal criteria, and 5 (33%) survived. The difference in average potassium values between sites or analytical method used was ≤1 mmol/L. The agreement between potassium values according to the three different sampling sites was poor. The ranges of the differences in potassium using BGA measurement were - 1.6 to + 1.7 mmol/L; - 1.18 to + 2.7 mmol/L and - 0.87 to + 2 mmol/L when comparing respectively central venous and peripheral venous, central venous and arterial, and peripheral venous and arterial potassium. We found important and clinically relevant variability in potassium values between sampling sites. Clinical decisions should not rely on one biological indicator. However, according to our results, the site of lowest potassium, and therefore the preferred site for a single potassium sampling is central venous blood. The use of multivariable prediction tools may help to mitigate the risks inherent in the limits of potassium measurement. ClinicalTrials.gov Identifier: NCT03096561

[Analysis of the accuracy of a coronary syndrome register]

National audienceRegisters of the management of infarction can complement information obtained from randomised trials evaluating the methods and practice of treatment. In order to do this, the quality of the registers must be assured, and in particular the accuracy of the recorded cases. The objective of this study was to evaluate the accuracy of a register for the in-hospital and pre-hospital management of acute coronary syndromes with ST segment elevation of less than 12 hours' duration. Using a capture-recapture method, the study compared cases in the register with eligible cases present in the hospital and emergency ambulance service databases at two establishments, giving a recruitment rate of 61%. The rate of accuracy was estimated at 84% (95% CI [82 ; 86]).The independent factors associated with failure of notification were female sex (ORa=6.65 [2.04-21.69]), presentation at nights, weekends or bank holidays (ORa=4.13 [1.33-12.85]), direct admission to hospital without passing by the emergency ambulance service (ORa=2.85 [1.03-7.69]), primary angioplasty (ORa=6.18 [1.60-23.79]) and the absence of reperfusion (ORa=40.38 [6.21-262.40]). With more than 80% accuracy, the results produced by the register are robust. The selection bias linked to the under-representation of certain subgroups, while real, has only a marginal impact on estimates derived from the register. Factors associated with failure of notification should be taken into account when operating such a register

The impact of hypothermia on serum potassium concentration: A systematic review.

Blood potassium is the main prognostic biomarker used for triage in hypothermic cardiac arrest. The aim of this review was to assess the impact of hypothermia on blood potassium levels and compare the underlying pathophysiological theories. The Medline electronic database was searched via PubMed for articles published from January 1970 to December 2016. The search strategy included studies related to hypothermia and potassium levels. The relevant literature on clinical studies and experimental studies was reviewed by the authors. Among the 50 studies included in the review, 39 (78%) reported a decrease in blood potassium levels upon hypothermia onset. Hypothermic hypokalaemia is linked to an intracellular shift rather than an actual net loss. The intracellular shift is caused by a variety of factors such as enhanced functioning of Na+K+ATPase, beta-adrenergic stimulation, pH and membrane stabilisation in deep hypothermia. In contrast, hypothermia can act as an aggravating factor in severe trauma with hyperkalaemia being an indicator of an irreversible state of cell death. An increase in the blood potassium level during hypothermia may result from a lack of enzyme functioning at cold temperatures and blocked active transport. Hypothermia causes an initial decrease of potassium levels; however, the final stage of hypothermic cardiac arrest can induce hyperkalaemia due to cell lysis and final depolarisation. Better understanding the physiopathology of potassium levels during accidental hypothermia could be critically important to better select patients who could benefit from aggressive resuscitation therapy such as extracorporeal cardiopulmonary resuscitation

[Comparison of mortality according to the revascularisation strategies and the symptom-to-management delay in ST-segment elevation myocardial infarction]

National audienceThe aim of this study was to compare the mortality associated to primary angioplasty and thrombolysis in patients managed for an elevated ST-segment acute coronary syndrome in less than or more than 3 hours after the onset of symptoms. We analyzed the in-hospital mortality of 846 patients (including 276 [33%] treated by primary angioplasty, 511 [60%] by thrombolysis, and 59 [7%] without revascularisation) included from October 2002 to December 2003 in a registry of patients with an elevated ST-segment acute coronary syndrome managed in less than 12 hours in Northern Alps districts. The overall in-hospital mortality was at 6.0% (51/846). For the 631 managed in 3 hours. These results are in line with randomized trials conclusions and confirm the international guidelines suggesting primary angioplasty for patients with a chest pain >3 hours and either angioplasty or thrombolysis in case of chest pain < 3 hours