Venous lactate levels can be used to identify patients with poor outcome following community-onset norovirus enteritis

Abstract

Background: Norovirus enteritis (NVE) can be fatal in frail patients. High blood lactate levels indicate hypoperfusion and predict mortality in many infectious diseases. The objective was to determine the frequency and association with mortality of elevated lactate levels in patients with community-onset NVE. Methods: A retrospective cohort study was performed. All hospitalized adult patients with community-onset NVE verified by polymerase chain reaction during the period August 2008 to June 2009 were included. Vital signs and venous lactate on arrival, co-morbid conditions, and time of death were registered. The outcome measure was 30-day all-cause mortality. Results: Eighty-two patients with a median age of 77 y (interquartile range (IQR) 53–86 y) were included, of whom 47 (57%) were female and 49 (60%) had at least 1 major co-morbid condition. Lactate levels were above the upper limit of normal (ULN; 1.6 mmol/l) in 45 patients (55%). The overall 30-day mortality rate was 7% (6/82). Mortality was 18% (5/28) with lactate ≥ 2.4 mmol/l (> 50% above the ULN) on admission compared to 2% (1/54) with lactate < 2.4 mmol/l (p < 0.05). Patients who died had a higher median lactate level compared to survivors: 4.5 (IQR 2.7–7.9) mmol/l vs 1.7 (IQR 1.3–2.5) mmol/l, respectively (p < 0.01). The adjusted odds ratio for death within 30 days for a 1 mmol/l increase in lactate was 2.5 (95% confidence interval 1.003–6.3, p = 0.049). Conclusions: We observed a high proportion of patients with elevated lactate levels in community-onset NVE. Lactate elevation could predict mortality. Measurement of blood lactate may be a valuable tool in the clinical management of patients with a suspected norovirus infection.

Keywords::

• Norovirus
• community-onset
• lactate
• mortality
• retrospective

Acknowledgements

EpiStat, University of Gothenburg, provided statistical advice and support, for which we are most grateful. The authors would also like to thank Monica Lohm and Marita Axelsson at the Department of Infectious Diseases, and Agneta Håkansson and the PCR/Detection Division of the Department of Clinical Virology, Sahlgrenska University Hospital.

Declaration of interest: This work was supported by grants from the Göteborg Medical Society (grant numbers GLS-10/101341 and GLS-11/171791), and the Västra Götaland Region Research Funds. There are no conflicts of interest reported.