Emergency Medical Services
Background: Measurement of lactate in the prehospital setting could be a useful tool for EMS providers. To date there have been a limited number of inexpensive handheld lactate meters on the market that could be used in the prehospital setting. Further, it will likely be more useful to EMS if a point-of-care meter can be used with either capillary or venous blood.
Objective: To compare point-of-care lactate meter measurements using both capillary and venous blood to laboratory values.
Methods: We evaluated the StatStrip Xpress Lactate Meter (Nova Biomedical) in children presenting to a pediatric emergency department who had a laboratory blood gas ordered by their treating provider. Patients were then asked to consent to having a capillary blood draw. The meter was used to measure the lactate in the patients’ capillary sample as well as some of the venous blood that was drawn for the laboratory analysis. The blood gas was analyzed using the ABL800 (Radiometer) and then was converted from mg/dL to mmol/L by multiplying by 0.111. A paired analysis was conducted using a paired t-test.
Results: 42 children provided all three blood samples. The mean age was 13 (SD 2.9) and 48% were male. The mean difference between the capillary blood meter value and the laboratory value was 1.1 (SD 3.5; p=0.058). The mean difference between the venous blood meter value and the laboratory value was -0.3 (SD 1.1, p=0.07). The mean difference between the venous blood meter value and the capillary meter value was 1.3 (SD 3.1, p=0.008).
Conclusion: There was variation between the meter obtained lactate values and the laboratory obtained lactate value. The meter venous blood samples were closer to the laboratory values then the meter capillary blood samples. This likely indicates that point-of-care lactate values obtained in the field using venous or capillary blood could be useful in helping to guide prehospital decisions, but care would need to be taken if these values are going to be used to examine trends in lactate values if the additional lactate values are obtaining using a different method of analysis.