Classification versus Prediction of Mortality Risk using the SIRS and qSOFA Scores in Patients with Infection Transported by Paramedics

Sepsis death risk factor score based on systemic inflammatory response syndrome, quick sequential organ failure assessment, and comorbidities

OBJECTIVE

In this study, we aimed to evaluate the death risk factors of patients included in the sepsis protocol bundle, using clinical data from qSOFA, SIRS, and comorbidities, as well as development of a mortality risk score.

DESIGN

This retrospective cohort study was conducted between 2016 and 2021.

SETTING

Two university hospitals in Brazil.

PARTICIPANTS

Patients with sepsis.

INTERVENTIONS

Several clinical and laboratory data were collected focused on SIRS, qSOFA, and comorbidities.

MAIN VARIABLE OF INTEREST

In-hospital mortality was the primary outcome variable. A mortality risk score was developed after logistic regression analysis.

RESULTS

A total of 1,808 patients were included with a death rate of 36%. Ten variables remained independent factors related to death in multivariate analysis: temperature ≥38 °C (odds ratio [OR] = 0.65), previous sepsis (OR = 1.42), qSOFA ≥ 2 (OR = 1.43), leukocytes >12,000 or <4,000 cells/mm3 (OR = 1.61), encephalic vascular accident (OR = 1.88), age >60 years (OR = 1.93), cancer (OR = 2.2), length of hospital stay before sepsis >7 days (OR = 2.22,), dialysis (OR = 2.51), and cirrhosis (OR = 3.97). Considering the equation of the binary regression logistic analysis, the score presented an area under curve of 0.668, is not a potential model for death prediction.

CONCLUSIONS

Several risk factors are independently associated with mortality, allowing the development of a prediction score based on qSOFA, SIRS, and comorbidities data, however, the performance of this score is low.

Prehospital pulse pressure and mortality of septic shock patients cared for by a mobile intensive care unit

BACKGROUND

Septic shock medical treatment relies on a bundle of care including antibiotic therapy and hemodynamic optimisation. Hemodynamic optimisation consists of fluid expansion and norepinephrine administration aiming to optimise cardiac output to reach a mean arterial pressure of 65mmHg. In the prehospital setting, direct cardiac output assessment is difficult because of the lack of invasive and non-invasive devices. This study aims to assess the relationship between 30-day mortality and (i) initial pulse pressure (iPP) as (ii) pulse pressure variation (dPP) during the prehospital stage among patients cared for SS by a prehospital mobile intensive care unit (MICU).

METHODS

From May 09th, 2016 to December 02nd, 2021, septic shock patients requiring MICU intervention were retrospectively analysed. iPP was calculated as the difference between systolic blood pressure (SBP) and diastolic blood pressure (DBP) at the first contact between the patient and the MICU team prior to any treatment and, dPP as the difference between the final PP (the difference between SBP and DBP at the end of the prehospital stage) and iPP divided by prehospital duration. To consider cofounders, the propensity score method was used to assess the relationship between (i) iPP < 40mmHg, (ii) positive dPP and 30-day mortality.

RESULTS

Among the 530 patients analysed, pulmonary, digestive, and urinary infections were suspected among 43%, 25% and 17% patients, respectively. The 30-day overall mortality rate reached 31%. Cox regression analysis showed an association between 30-day mortality and (i) iPP < 40mmHg; aHR of 1.61 [1.03-2.51], and (ii) a positive dPP; aHR of 0.56 [0.36-0.88].

CONCLUSION

The current study reports an association between 30-day mortality rate and iPP < 40mmHg and a positive dPP among septic shock patients cared for by a prehospital MICU. A negative dPP could be helpful to identify septic shock with higher risk of poor outcome despite prehospital hemodynamic optimization.

Evidence for Use of Validated Sepsis Screening Tools in the Prehospital Population: A Scoping Review

INTRODUCTION

Early detection and treatment of sepsis improves chances of survival; however, sepsis is often difficult to diagnose initially. This is especially true in the prehospital setting, where resources are scarce, yet time is of great significance. Early warning scores (EWS) based on vital signs were originally developed to guide medical practitioners in determining the degree of illness of a patient in the in-patient setting. These EWS were adapted for use in the prehospital setting to predict critical illness and sepsis. We performed a scoping review to evaluate the existing evidence for use of validated EWS to identify prehospital sepsis.

METHODS

We performed a systematic search using the CINAHL, Embase, Ovid-MEDLINE, and PubMed databases on September 1, 2022. Articles that examined the use of EWS to identify prehospital sepsis were included and assessed.

RESULTS

Twenty-three studies were included in this review: one validation study, two prospective studies, two systematic reviews, and 18 retrospective studies. Study characteristics, classification statistics, and primary conclusions of each article were extracted and tabulated. Classification statistics varied markedly for prehospital sepsis identification across all included EWS: sensitivities ranged from 0.02-1.00, specificities from 0.07-1.00, and PPV and NPV from 0.19-0.98 and 0.32-1.00, respectively.

CONCLUSIONS

All studies demonstrated inconsistency for the identification of prehospital sepsis. The variety of available EWS and study design heterogeneity suggest it is unlikely that new research can identify a single gold standard score. Based on our findings in this scoping review, we recommend future efforts focus on combining standardized prehospital care with clinical judgment to provide timely interventions for unstable patients where infection is considered a likely etiology, in addition to improving sepsis education for prehospital clinicians. At most, EWS can be used as an adjunct to these efforts, but they should not be relied on alone for prehospital sepsis identification.

Association between prehospital shock index variation and 28-day mortality among patients with septic shock

PURPOSE

Septic shock (SS) hyperdynamic phase is characterized by tachycardia and low-blood pressure reflecting the relative hypovolemia. Shock index (SI), the ratio between heart rate and systolic blood pressure, is a simple objective tool, usable for SS prognosis assessment. This study aims to evaluate the relationship between prehospital SI variation and 28-day mortality of SS patients initially cared for in prehospital setting by a mobile intensive care unit (mICU).

METHODS

From April 6th, 2016 to December 31st, 2020, 406 patients with SS requiring prehospital mICU were retrospectively analyzed. Initial SI, i.e. first measurement after mICU arrival to the scene, and final SI, i.e. last measurement of the prehospital stage, were used to calculate delta SI (initial SI-final SI) and to define positive and negative delta SI. A survival analysis after propensity score matching compared the 28-day mortality of SS patients with positive/negative delta SI.

RESULTS

The main suspected origins of infection were pulmonary (42%), digestive (25%) and urinary (17%). The 28-day overall mortality reached 29%. Cox regression analysis revealed a significant association between 28-day mortality and delta SI. A negative delta SI was associated with an increase in mortality (adjusted hazard ratio (HRa) of 1.88 [1.07-3.31] (p = 0.03)), whereas a positive delta SI was associated with a mortality decrease (HRa = 0.53 [0.30-0.94] (p < 10-3)).

CONCLUSION

Prehospital hemodynamic delta SI among SS patients cared for by a mICU is associated with 28-day mortality. A negative prehospital delta SI could help physicians to identify SS with higher risk of 28-day mortality.

Relationship between the prehospital quick Sequential Organ Failure Assessment and prognosis in patients with sepsis or suspected sepsis: a population-based ORION registry

Aim

The quick Sequential Organ Failure Assessment (qSOFA) was proposed for use as a simple screening tool for sepsis. In this study, we evaluated the relationship between the prehospital use of qSOFA and prognosis in patients with sepsis or suspected sepsis using the population‐based Osaka Emergency Information Research Intelligent Operation Network (ORION) registry, which compiles prehospital ambulance data and in‐hospital information.

Methods

The study enrolled 437,974 patients in the ORION registry from January 1 to December 31, 2016. We selected hospitalized patients with sepsis or suspected sepsis using the appropriate codes from the International Classification of Diseases revision 10. We excluded patients with: (i) missing data (outcome, Japan Coma Scale, respiratory rate, and blood pressure); (ii) respiratory rate ≥60/min; and (iii) blood pressure ≥250 mmHg. These measures were evaluated by ambulance personnel when they first contacted the patient in the prehospital setting. The primary end‐point was discharge to death.

Results

In total, 12,646 patients (median age, 78 [interquartile range, 65–85] years; male, n = 6,760 [53.5%]) were eligible for our analysis. In a multivariable logistic regression analysis adjusted for confounding factors, the proportion of patients discharged to death was significantly higher for those evaluated as qSOFA positive (≥2 points) than qSOFA negative (≤1 point) (265/2,250 [11.78%] vs. 415/10,396 [3.99%]; adjusted odds ratio 2.91; 95% confidence interval, 2.47–3.43; P < 0.0001). The specificity and sensitivity were 83.4% and 39.0%, respectively, and the area under the receiver operating characteristic curve for qSOFA positive was 0.61.

Conclusions

The qSOFA evaluated by ambulance personnel in the prehospital setting was significantly associated with prognosis in patients with sepsis or suspected sepsis.

Pre-Hospital Lactatemia Predicts 30-Day Mortality in Patients with Septic Shock-Preliminary Results from the LAPHSUS Study

Background: Assessment of disease severity in patients with septic shock (SS) is crucial in determining optimal level of care. In both pre- and in-hospital settings, the clinical picture alone is not sufficient for assessing disease severity and outcomes. Because blood lactate level is included in the clinical criteria of SS it should be considered to improve the assessment of its severity. This study aims to investigate the relationship between pre-hospital blood lactate level and 30-day mortality in patients with SS. Methods: From 15 April 2017 to 15 April 2019, patients with SS requiring pre-hospital Mobile Intensive Care Unit intervention (MICU) were prospectively included in the LAPHSUS study, an observational, non-randomized controlled study. Pre-hospital blood lactate levels were measured at the time of first contact between the patients and the MICU. Results: Among the 183 patients with septic shock requiring action by the MICU drawn at random from LAPHSUS study patients, six (3%) were lost to follow-up on the 30th day and thus 177 (97%) were analyzed for blood lactate levels (mean age 70 ± 14 years). Pulmonary, urinary and digestive infections were probably the cause of the SS in respectively 58%, 21% and 11% of the cases. The 30-day overall mortality was 32%. Mean pre-hospital lactatemia was significantly different between patients who died and those who survived (respectively 7.1 ± 4.0 mmol/L vs. 5.9 ± 3.5 mmol/L, p < 10⁻³). Using Cox regression analysis adjusted for potential confounders we showed that a pre-hospital blood lactate level ≥ 4 mmol/L significantly predicted 30-day mortality in patients with SS (adjusted hazard ratio = 2.37, 95%CI (1.01–5.57), p = 0.04). Conclusion: In this study, we showed that pre-hospital lactatemia predicts 30-day mortality in patients with septic shock handled by the MICU. Further studies will be needed to evaluate if pre-hospital lactatemia alone or combined with clinical scores could affect the triage decision-making process for those patients.

Screening strategies to identify sepsis in the prehospital setting: a validation study

BACKGROUND

In the prehospital setting, differentiating patients who have sepsis from those who have infection but no organ dysfunction is important to initiate sepsis treatments appropriately. We aimed to identify which published screening strategies for paramedics to use in identifying patients with sepsis provide the most certainty for prehospital diagnosis.

METHODS

We identified published strategies for screening by paramedics through a literature search. We then conducted a validation study in Alberta, Canada, from April 2015 to March 2016. For adult patients (≥ 18 yr) who were transferred by ambulance, we linked records to an administrative database and then restricted the search to patients with infection diagnosed in the emergency department. For each patient, the classification from each strategy was determined and compared with the diagnosis recorded in the emergency department. For all strategies that generated numeric scores, we constructed diagnostic prediction models to estimate the probability of sepsis being diagnosed in the emergency department.

RESULTS

We identified 21 unique prehospital screening strategies, 14 of which had numeric scores. We linked a total of 131 745 eligible patients to hospital databases. No single strategy had both high sensitivity (overall range 0.02-0.85) and high specificity (overall range 0.38-0.99) for classifying sepsis. However, the Critical Illness Prediction (CIP) score, the National Early Warning Score (NEWS) and the Quick Sepsis-Related Organ Failure Assessment (qSOFA) score predicted a low to high probability of a sepsis diagnosis at different scores. The qSOFA identified patients with a 7% (lowest score) to 87% (highest score) probability of sepsis diagnosis.

INTERPRETATION

The CIP, NEWS and qSOFA scores are tools with good predictive ability for sepsis diagnosis in the prehospital setting. The qSOFA score is simple to calculate and may be useful to paramedics in screening patients with possible sepsis.

Epidemiology and patient predictors of infection and sepsis in the prehospital setting

PURPOSE

Paramedics are often the first healthcare contact for patients with infection and sepsis and may identify them earlier with improved knowledge of the clinical signs and symptoms that identify patients at higher risk.

METHODS

A 1-year (April 2015 and March 2016) cohort of all adult patients transported by EMS in the province of Alberta, Canada, was linked to hospital administrative databases. The main outcomes were infection, or sepsis diagnosis among patients with infection, in the Emergency Department. We estimated the probability of these outcomes, conditional on signs and symptoms that are commonly available to paramedics.

RESULTS

Among 131,745 patients transported by EMS, the prevalence of infection was 9.7% and sepsis was 2.1%. The in-hospital mortality rate for patients with sepsis was 28%. The majority (62%) of patients with infections were classified by one of three dispatch categories ("breathing problems," "sick patient," or "inter-facility transfer"), and the probability of infection diagnosis was 17-20% for patients within these categories. Patients with elevated temperature measurements had the highest probability for infection diagnosis, but altered Glasgow Coma Scale (GCS), low blood pressure, or abnormal respiratory rate had the highest probability for sepsis diagnosis.

CONCLUSION

Dispatch categories and elevated temperature identify patients with higher probability of infection, but abnormal GCS, low blood pressure, and abnormal respiratory rate identify patients with infection who have a higher probability of sepsis. These characteristics may be considered by paramedics to identify higher-risk patients prior to arrival at the hospital.

Back to Basics: Recognition of Sepsis with New Definition

Patients with serious infections at risk of deterioration represent highly challenging clinical situations, and in particular for junior doctors. A comprehensive clinical examination that integrates the assessment of vital signs, hemodynamics, and peripheral perfusion into clinical decision making is key to responding promptly and effectively to evolving acute medical illnesses, such as sepsis or septic shock. Against this background, the new concept of sepsis definition may provide a useful link between junior doctors and consultant decision making. The purpose of this article is to introduce the updated definition of sepsis and suggest its practical implications, with particular emphasis on integrative clinical assessment, allowing for the rapid identification of patients who are at risk of further deterioration.