Lactate clearance in infants undergoing surgery for congenital heart disease.

Measurement of lactate concentrations during cardiac surgery with cardiopulmonary bypass (CPB) is a reliable monitoring tool for the assessment of the adequacy of perfusion, and a predictor of poor outcome. However, increased lactate production, which is multifactorial (anaerobic metabolism, hyperglycemia), increased lactate load by packed red blood cell (PRBC) transfusions, and decreased lactate clearance may all result in hyperlactatemia. The aim of this study was to estimate the clearance of lactate in infants undergoing surgery with CPB, using the lactate load from the PRBCs transfusions received during CPB. Retrospective cohort of infants <1 year of age with repeated lactate measurements during CPB, and a known lactate concentration in the PRBCs used during CPB were evaluated. All patients received PRBCs in the prime and during CPB to maintain hematocrit >35% and venous saturation >70%. Lactate kinetics were estimated across several time intervals between two lactate measurements, using a single compartment model. The lactate load was calculated as the product: PRBC-lactate concentration * volume. The rate of endogenous lactate production was assumed to be unchanged (maintenance of high oxygen deliveries and normoglycemia throughout CPB). Overall, 87 calculations were performed in 27 patients, then averaged per patient. The mean lactate half-life was 12.36 min [10.67-14.06], the mean clearance was 0.09 L/min [0.06-0.11], the indexed lactate clearance was 0.36 L/min/m2 [0.28-0.44]. Lactate clearance increased significantly with age. The half-life of lactate in infants is comparable with that reported in adults with CPB, and lactate clearance is higher. Knowing the high lactate content of PRBCs, lactate clearance rather than absolute concentration is potentially a better indicator of the adequacy of perfusion during CPB in infants.

What is the relevancy of a surveillance of mumps without a systematic laboratory confirmation in highly immunized populations? Epidemiology of suspected and biologically confirmed mumps cases seen in general practice in France between 2014 and 2020.

BACKGROUND: In France, mumps surveillance is conducted in primary care by the Sentinelles network, the National Reference Centre for Measles, Mumps and Rubella and Santé publique France. AIM: The objective of this study was to estimate the incidence of suspected mumps in general practice, the proportion of laboratory confirmed cases and the factors associated with a virological confirmation. METHODS: General practitioners (GPs) participating in the Sentinelles network should report all patients with suspected mumps according to a clinical definition in case of parotitis and a serological definition in case of clinical expression without parotitis. All suspected mumps cases reported between January 2014 and December 2020 were included. A sample of these cases were tested by real time reverse transcriptase polymerase chain reaction (RT-PCR) for mumps biological confirmation. RESULTS: A total of 252 individuals with suspected mumps were included in the study. The average annual incidence rate of suspected mumps in general practice in France between 2014 and 2020 was estimated at 11 cases per 100,000 population [CI95%: 6-17]. A mumps confirmation RT-PCR test was performed on 146 cases amongst which 17 (11.5 %) were positive. Age (between 20 and 29 years old), the presence of a clinical complication and an exposure to a suspected mumps case within the 21 days prior the current episode were associated with a mumps biological confirmation. CONCLUSION: If these results confirm the circulation of mumps virus in France, they highlight the limits of a surveillance without a systematic laboratory confirmation in highly immunized populations.