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.

BACKGROUND: Emergency Medical Services (EMS) are faced daily with patients presenting with non-specific chief complaints (NSC). Patients presenting with NSCs often have normal vital signs. It has previously been established that NSCs may have a serious underlying condition that has yet to be identified. The aim of the current study was to determine if soluble urokinase plasminogen activator receptor (suPAR) and lactate could be used to identify serious conditions among patients presenting with NSCs to the EMS. The secondary aim was to describe the prognostic value for mortality in the group. METHOD: A blinded prospective observational cohort study was conducted of patients brought to the ED by ambulance after calling the national emergency number 112 and who were assessed as having NSC by the EMS. Biomarkers were measured during index EMS assessment before transportation to the ED. Patients were followed via EMS and hospital electronic health records. Descriptive and logistic regression analyses were used. RESULTS: A total of 414 patients were included, with a median age of 82 years. A serious condition was present in 15.2% of the patients. Elevated suPAR above 3 ng/ml had a positive likelihood ratio (LR+) of 1.17 and a positive predictive value (PPV) of 17.3% as being predictive of a prevalent serious condition. Elevated suPAR above 9 ng/ml had LR+ 4.67 and a PPV of 16.7% as being predictive of 30-day mortality. Lactate was not significantly predictive. CONCLUSION: Pre-hospital suPAR and lactate cannot differentiate serious conditions in need of urgent treatment and assessment in the ED among patients presenting with non-specific chief complaints. suPAR has shown to be predictive of 30-day mortality, which could add some value to the clinical assessment. TRIAL REGISTRATION: NCT03089359. Registered 20 March 2017, retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03089359 .

Serious conditions among patients with non-specific chief complaints in the pre-hospital setting: a retrospective cohort study.

BACKGROUND: Emergency Medical Services (EMS) are faced daily with patients presenting with a non-specific chief complaints (NSC); i.e. decreased general condition, general malaise, sense of illness, or just being unable to cope with usual daily activities. Patients presenting with NSCs often have normal vital signs. It has previously been established that however, NSCs may have a serious underlying condition that has yet to be identified. The primary outcome of this study was to determine the prevalence of serious conditions in patients presenting with NSCs to the EMS. METHOD: A retrospective cohort study of patients ≥18 years of age who were reported as presenting with chief complaints compatible with NSCs to the EMS in Stockholm Region and transported to an emergency department between January 1st, 2013 and December 31st, 2013. Patients were identified via the EMS electronic health care record and followed via records from the National Patient Registry and Causes of Death Registry at Sweden's National Board for Health and Welfare. The definition of serious condition was defined by expert consensus. Descriptive statistics as well as regression analyses were used. RESULTS: A total of 3780 patients were included, with a median age of 77 years. A serious condition was present in 35.3% of the patients. The in-hospital mortality rate for the group with serious conditions was 10.1% (OR 6.8, CI 95%, 4.1-11.3), and the 30-day mortality rate was 20.2% (OR 3.1, CI 95%, 2.3-4.0). In the group with no serious conditions the rates were 1.0 and 4.2%, respectively. The total hospitalization rate was 67.6%. The presence of serious conditions as well as increased mortality rates were associated with Rapid Emergency Triage and Treatment system (RETTS) as well as National Early Warning Score (NEWS) irrespective of triage score. CONCLUSION: More than one-third of the patients presenting with NSCs to EMS had a serious underlying condition which was associated with increased mortality and hospitalization rates. TRIAL REGISTRATION: Not applicable.