Soluble urokinase plasminogen activator receptor and lactate as prognostic biomarkers in patients presenting with non-specific chief complaints in the pre-hospital setting - the PRIUS-study

The use and impact of prehospital blood lactate measurements in acute non-traumatic patients: a systematic review

BACKGROUND

The prehospital use of blood lactate measurements is increasing. However, the test's benefits have not been methodically evaluated in non-trauma patients. This study had three aims: (1) To assess the evidence of prehospital blood lactate measurements' prognostic value in non-trauma patients, (2) to investigate to what extent the test changed early patient treatment, and (3) to evaluate the healthcare personnel's attitude towards the test.

METHODS

MEDLINE, Embase, and Cochrane Central Register of Controlled Trials were systematically searched until Aug 26, 2023. Cohort and randomized controlled trials assessing ≥ 20 acute non-trauma patients with prehospital lactate measurements were included if they reported (1) prognostic outcomes such as short-term mortality or (2) changes in early patient treatments. All study designs were included to assess (3) the healthcare personnel's opinion on prehospital lactate measurements. The risks of bias were assessed using the QUIPS tool, the Newcastle-Ottawa Scale, and the RoB-2. Study registration number CRD42020167169 (PROSPERO).

RESULTS

We screened 6028 study reports. We included 15 studies on (1) the prognostic value of prehospital lactate measurements. Elevated blood lactate levels were correlated to a higher short-term mortality risk in most of the studies but not in studies with out-of-hospital cardiac arrest (OHCA) patients. The 15 prognostic studies were all cohort studies with moderate or high risks of bias. Four studies investigated (2) early treatment changes. They found that the prehospital lactate measurement may have changed early treatment in sepsis patients. However, all four studies on treatment changes were at high risk of bias. Four studies were included on (3) the healthcare personnel's attitude towards the lactate measurement. Evidence of the healthcare personnel's opinion on prehospital lactate measurements was scarce.

CONCLUSION

Most acute non-trauma patients with elevated prehospital lactate levels had increased risks of short-term mortality, except OHCA patients. Few studies suggested that measuring prehospital lactate levels could change early patient care, particularly in patients with suspected sepsis. The certainty of the evidence is low in this systematic review. The included studies were heterogeneous, and many had high risks of bias. Further studies are needed to investigate the impact of prehospital lactate measurements on patient care.

Serious conditions among conveyed and non-conveyed patients presenting with nonspecific chief complaints to the ambulance service

BACKGROUND

It is a challenge for the ambulance service to identify which patients to convey to the emergency department (ED). Ideally this would be the patients with serious conditions requiring further care in the ED. However, patients presenting with non-specific chief complaints are difficult to prioritize and typically have normal or near normal vital signs despite up to one third having underlying serious conditions. The proportion of patients with serious conditions among non-conveyed patients with non-specific chief complaints (NSC) as assessed by ambulance clinicians is not known. Therefore, the primary aim was to study the proportion of serious conditions among conveyed and non-conveyed patients presenting to the ambulance service with NSCs. The secondary aim was to study the mortality rate among patients with NSCs in relation to conveyance and serious and nonserious conditions.

METHOD

A retrospective cohort study of patients ≥ 18 years of age presenting with NSCs to the ambulance service in Stockholm Region between January 1st, 2013 and December 31st, 2013. Patients were identified via the ambulance service electronic health record and followed via records from the the National Patient Register and Causes of Death Registry at Sweden's National Board for Health and Welfare. Descriptive statistics as well as regression analyses were used.

RESULTS

A total of 4744 patients were included with a median age of 76 years. A serious condition was present in 1398 (29.5%) of the patients. After index assessment by the ambulance service, 3780 (79.7%) were conveyed of which 1334 (35.3%) had serious conditions, compared to 964 (20.3%) who were non-conveyed of which 64 (6.6%) had serious conditions. 30-day mortality was 372 (9.8%) in the conveyance group compared to 32 (3.3%) in the non-conveyance group. If serious conditions were present, the mortality rates were 269 (20.2%) in the conveyance group compared to 11 (17.2%) in the non-conveyance group.

CONCLUSION

The results show that serious conditions were more than five times more common among conveyed as compared to non-conveyed patients. Mortality rates were three times higher in the conveyance group as compared to the non-conveyance group. Our results suggest that the ambulance personnel play an important role in identifying patients with serious conditions, hence, likely to be in need of treatment in the ED.

TRIAL REGISTRATION

N/A.

Added predictive value of prehospital measurement of point-of-care lactate in an adult general EMS population in Sweden: a multi-centre observational study

BACKGROUND

Emergency medical services (EMS) personnel must rapidly assess and transport patients with time-sensitive conditions to optimise patient outcomes. Serum lactate, a valuable in-hospital biomarker, has become more accessible in EMS settings through point-of-care (POC) testing. Although POC lactate levels are valuable in specific patient groups, its broader application in EMS remains unclear. This study assessed the additional predictive value of POC lactate levels in a general adult EMS population.

METHODS

This prospective observational study (March 2018 to September 2019) involved two EMS organisations in Västra Götaland, Sweden. Patients were triaged using the Rapid Triage and Treatment System (RETTS). POC lactate levels were measured using StatStrip Xpress devices. Non-consecutive patients who received EMS and were aged 18 years and above were available for inclusion if triaged into RETTS levels: red, orange, yellow, or green if respiratory rate of ≥ 22 breaths/min. Outcomes were adverse outcomes, including a time-sensitive diagnosis, sequential organ failure assessment (SOFA) score ≥ 2, and 30-day mortality. Statistical analyses included descriptive statistics, imputation, and regression models to assess the impact of the addition of POC lactate levels to a base model (comprising patient age, sex, presence of past medical conditions, vital signs, pain, EMS response time, assessed triage condition, and triage level) and a RETTS triage model.

RESULTS

Of 4,546 patients (median age 75 [57, 84] years; 49% male), 32.4% had time-sensitive conditions, 12.5% met the SOFA criteria, and 7.4% experienced 30-day mortality. The median POC lactate level was 1.7 (1.2, 2.5) mmol/L. Patients with time-sensitive conditions had higher lactate levels (1.9 mmol/L) than those with non-time-sensitive conditions (1.6 mmol/L). The probability of a time-sensitive condition increased with increasing lactate level. The addition of POC lactate marginally enhanced the predictive models, with a 1.5% and 4% increase for the base and RETTS triage models, respectively. POC lactate level as a sole predictor showed chance-only level predictive performance.

CONCLUSIONS

Prehospital POC lactate assessment provided limited additional predictive value in a general adult EMS population. However, it may be beneficial in specific patient subgroups, emphasizing the need for its judicious use in prehospital settings.

Role of soluble urokinase type plasminogen activator receptor (suPAR) in predicting mortality, readmission, length of stay and discharge in emergency patients: A systematic review and meta analysis

BACKGROUND

Soluble urokinase plasminogen activator receptor (suPAR) is an inflammatory biomarker that is used to predict mortality, readmission, early discharge, and LOS, thus, serves as a useful tool for ED physicians. Our study aims to analyze the efficacy of suPAR in predicting these prognostic markers in ED.

METHODS

We performed a comprehensive search on 6 databases from the inception to 30th November 2022, to select the following eligibility criteria; a) observation or triage trial studies investigating the role of suPAR levels in predicting: 30 day and 90-day mortality, 30-day readmission, early discharge (within 24hr), and LOS in patients coming to AMU.

RESULTS

A total of 13 studies were included, with a population size of 35,178, of which 52.9% were female with a mean age of 62.93 years. Increased risk of 30-day mortality (RR = 10.52; 95% CI = 4.82-22.95; I2 = 38%; P < .00001), and risk of 90-day mortality (RR = 5.76; 95% CI = 3.35-9.91; I2 = 36%; P < .00001) was observed in high suPAR patients. However, a slightly increased risk was observed for 30-day readmission (RR = 1.50; 95% CI = 1.16-1.94; I2 = 54%; P = .002). More people were discharged within 24hr in the low suPAR level group compared to high suPAR group (RR = 0.46; 95% CI = 0.40-0.53; I2 = 41%; P < .00001). LOS was thrice as long in high suPAR level patients than in patients with low suPAR (WMD = 3.20; 95% CI = 1.84-4.56; I2 = 99%; P < .00001).

CONCLUSION

suPAR is proven to be a significant marker in predicting 30-day and 90-day mortality in ED patients.

Pre-hospital emergency nurse specialist's experiences in caring for patients with non-specific chief complaints in the ambulance - A qualitative interview study

BACKGROUND

Pre-hospital emergency nurse (PEN) specialists are faced with patients presenting with non-specific chief complaints (NSC) to the emergency medical service (EMS) on a daily basis. These patients are often elderly and one in three has a serious condition and their acuity is not recognized.

OBJECTIVE

The aim of the current study was to explore PEN specialists' experiences in caring for patients presenting with non-specific chief complaints.

DESIGN

A qualitative study design with eleven individual interviews of PENs, between 2018 and 2020. Qualitative content analysis was used.

RESULTS

The analyses generated three categories including subcategories. The categories were "Unexplained suffering". "Systematic approach and experience enhances medical safety". "Organizational processes can be optimized". The relation between the categories compiled as ́In-depth systematic assessment is perceived to reduce suffering and increases patient safetý.

CONCLUSION

The PENs experiences in caring for patients presenting with non-specific chief complaints show that an in-depth systematic assessment may lead to a meaningful caring encounter which enables the identification of the cause of the chief complaint. Experience and a systematic approach were considered as essential to enhance medical safety. This could be strengthened through feedback on the nurse's care provided by care managers and employers. To optimize organizational processes, the development of the opportunity to convey the patient to different levels of care can be an important component.

Utilization of Prognostic Biomarker Soluble Urokinase Plasminogen Activator Receptor in the Emergency Department: A Tool for Safe and More Efficient Decision-making

Introduction:

Risk stratification in the emergency departments (EDs) is in critical need for new applications due to ED overcrowding and hospitalization of older people. We aimed to evaluate the expediency, efficiency and safety of a prognostic biomarker, soluble urokinase plasminogen activator receptor (suPAR), as a tool for the risk assessment of patients arriving at the ED.

Methods:

We performed a comparative cross-sectional study in 2 emergency departments (EDs), suPAR measurements being incorporated into routine blood sampling in the intervention ED. The primary outcome was the number of discharges from the ED. The importance of the outcomes was examined by appropriate multi- or bivariate analysis.

Results:

The absolute and relative number of discharges were similar between the intervention and control groups [121 (55.3%) vs 62 (55.9%)]. No significant differences between the groups were seen in the length of stays in the ED. Patients with low suPAR values were more likely discharged and patients with high suPAR values more likely admitted to hospital. Two admitted patients with low suPAR values could have been discharged safely.

Conclusion:

The utilization of suPAR did not increase the risk for neither positive nor negative outcomes. Low suPAR values could be potential in discharging more patients safely. Instead of unselected patient populations, the benefits of suPAR measurements in the ED could emerge in the assessment of a more precisely determined and selected group of patients.