Prehospital Lactate Measurement by Emergency Medical Services in Patients Meeting Sepsis Criteria

Abstract

IntroductionWe aimed to pilot test the delivery of sepsis education to emergency medical services (EMS) providers and the feasibility of equipping them with temporal artery thermometers (TATs) and handheld lactate meters to aid in the prehospital recognition of sepsis.MethodsThis study used a convenience sample of prehospital patients meeting established criteria for sepsis. Paramedics received education on systemic inflammatory response syndrome (SIRS) criteria, were trained in the use of TATs and hand-held lactate meters, and enrolled patients who had a recent history of infection, met ≥ 2 SIRS criteria, and were being transported to a participating hospital. Blood lactate was measured by paramedics in the prehospital setting and again in the emergency department (ED) via usual care. Paramedics entered data using an online database accessible at the point of care.ResultsPrehospital lactate values obtained by paramedics ranged from 0.8 to 9.8 mmol/L, and an elevated lactate (i.e. ≥ 4.0) was documented in 13 of 112 enrolled patients (12%). The unadjusted correlation of prehospital and ED lactate values was 0.57 (p< 0.001). The median interval between paramedic assessment of blood lactate and the electronic posting of the ED-measured lactate value in the hospital record was 111 minutes. Overall, 91 patients (81%) were hospitalized after ED evaluation, 27 (24%) were ultimately diagnosed with sepsis, and 3 (3%) died during hospitalization. Subjects with elevated prehospital lactate were somewhat more likely to have been admitted to the intensive care unit (23% vs 15%) and to have been diagnosed with sepsis (38% vs 22%) than those with normal lactate levels, but these differences were not statistically significant.ConclusionIn this pilot, EMS use of a combination of objective SIRS criteria, subjective assessment of infection, and blood lactate measurements did not achieve a level of diagnostic accuracy for sepsis that would warrant hospital prenotification and committed resources at a receiving hospital based on EMS assessment alone. Nevertheless, this work provides an early model for increasing EMS awareness and the implementation of novel devices that may enhance the prehospital assessment for sepsis. Additional translational research studies with larger numbers of patients and more robust methods are needed.

Accuracy of prehospital point‐of‐care lactate in early in‐hospital mortality

“…In order to study pLA triggers or cut‐off points we used already described thresholds 10,11 . The accuracy of pLA triggers presented relevant results which are consistent with previous studies 7,14,23 . For instance, values above 4 mmol/L, which represents a state of hyperlactatemia, 24,25 showed a significant increase in mortality.…”

“…Our outcome is more restrictive than other similar studies with higher early mortality data, but with a longer temporal window, that is more than two days. 7,14,21,22 F I G U R E 1 Flow chart showing analysis population. 1 On-site resolution: either the ALS physician has been able to stabilize the patient on the scene and his/her condition was no longer serious or once the patient has been evaluated it was found that he/she does not needed any type of manoeuvre or be transferred to the ED.…”

“…10,11 The accuracy of pLA triggers presented relevant results which are consistent with previous studies. 7,14,23 For instance, values above 4 mmol/L, which represents a state of hyperlactatemia, 24,25 showed a significant increase in mortality. Values below 2 mmol/L, which F I G U R E 2 A, Receiver operational characteristic (ROC) of pLA for in-hospital mortality.…”

“…5 Among all the available biomarkers, lactate is distinctive in two characteristics: easy to obtain while it is a very reliable indicator of anaerobic metabolism and poor prognosis, what it makes it being used in different clinical contexts and for different pathological processes. 6,7 Lactate values above 2 mmol/L can cause the appearance of nonspecific symptoms, even with normal vital signs and may delay early diagnostic and therapeutic actions. 8 High levels of lactate sustained over time are associated with an increase of in-hospital mortality and a worsening of the patient's prognosis.…”

Derivation and internal validation of the screening to enhance prehospital identification of sepsis (SEPSIS) score in adults on arrival at the emergency department

“…Lactate is not measured by ambulance crews in the participating ambulance service, therefore it was not available for consideration during SEPSIS score development. However, it has been reported that inclusion of prehospital lactate does not improve prehospital identification of sepsis [62]. Secondly, Hunter et al argued that end-tidal carbon dioxide (EtCO 2 ) measured by EMS was an important predictor of sepsis, severe sepsis and mortality, reporting an AUROC of 0.99 (95%CI 0.99–1.0), 0.80 (95%CI 0.73–0.86) and 0.70 (95%CI 0.57–0.83) respectively [63].…”