Assessing The Predictive Value of Clinical Factors Used to Determine The Presence of Sepsis Causing Shock in the Emergency Department

Computed tomography for detection of septic foci: Retrospective analysis of patients presenting to the emergency department

OBJECTIVE

Sepsis is defined as organ dysfunction due to severe infection. Septic patients face a significant mortality risk. Thus, timely recognition with prompt focus identification and control are essential. This study aims to determine the current role of computed tomography (CT) in the diagnostic workup of septic patients.

METHODS

We retrospectively identified 357 patients in the emergency department (ED) of a large university center with suspected sepsis in a two-year period. A total of 132 patients underwent CT scanning within 72 h of admission. Patients were characterized by clinical and laboratory findings. CT reports were categorized and matched with clinical data.

RESULTS

Of 357 ED patients with suspected sepsis, 37.0% (132/357) underwent CT imaging within 72 h. The most commonly identified septic foci in CT were chest 38.6% (49/127), abdomen 22.0% (28/127) and genitourinary tract 20.5% (26/127) in descending order. The focus detection rate was 76.5% per patient with a concurrent number-needed-to-scan of 1.31. Contrast medium administration in CT did not improve focus detection rate (p = 0.631) or diagnostic confidence in this patient population (p = 0.432). CT had a positive predictive value of 81.82% (CI 76.31 to 86.28%) in predicting the focus of the discharge diagnosis. Follow-up imaging in patients with unclear focus reveals a new focus in 39.5% of patients.

CONCLUSIONS

Our investigation of the role of CT in ED patients with suspected sepsis indicated a high positive predictive value for CT with regard to the discharge diagnosis. Repeat imaging may help identify further septic foci in a subgroup with persistently unclear focus. Use of contrast medium seems less relevant for focus detection than expected, as it did not increase diagnostic confidence.

Predicting Prolonged Intensive Care Unit Stay Among Patients With Sepsis-Induced Hypotension

BACKGROUND

Sepsis risk stratification tools typically predict mortality, although stays in the intensive care unit (ICU) of 24 hours or longer may be more clinically relevant for emergency department disposition.

OBJECTIVE

To explore predictors of ICU stay of 24 hours or longer among infected, hypotensive emergency department patients.

METHODS

A secondary analysis of 2 prospective, observational studies of adult patients with severe sepsis or an infection with a systolic blood pressure less than 90 mm Hg in 3 urban, academic emergency departments was performed. Patients with hypotension and infection were included. Patients with emergency department intubation, vasopressor administration, and/or death were excluded. The primary outcome was ICU stay of 24 hours or longer or death in less than 24 hours. Multivariable logistic regression was used to predict ICU stay of 24 hours or longer.

RESULTS

Of 233 patients, 108 (46.4%) had ICU stays of 24 hours or longer. History of heart failure (odds ratio, 3.6; 95% CI, 1.5-8.3), bicarbonate level less than 20 mEq/L (odds ratio, 2.0; 95% CI, 1.1-3.8), respiratory rate greater than 20/min (odds ratio, 2.0; 95% CI, 1.1-3.7), and creatinine level greater than 2.0 mg/dL (odds ratio, 3.6; 95% CI, 1.9-6.7) were independent predictors of ICU stay of 24 hours or longer (area under curve, 0.74). The presence of 1 of these factors predicted ICU stay of 24 hours or longer (area under curve, 0.74) with 82.4% sensitivity and 49.6% specificity.

CONCLUSIONS

These exploratory results show that heart failure, bicarbonate level of less than 20 mEq/L, tachypnea, or creatinine level greater than 2.0 mg/dL increases the likelihood of an ICU stay of 24 hours or longer among infected, hypotensive emergency department patients.

Identification of Hypotensive Emergency Department Patients with Cardiogenic Etiologies

OBJECTIVE

Identify predictors of cardiogenic etiology among emergency department (ED) patients with hypotension, and use these predictors to create a clinical tool to discern cardiogenic etiology of hypotension.

METHODS

This secondary analysis evaluated a prospective cohort of consecutive patients with hypotension in an urban, academic, tertiary care ED from November 2012 to September 2013. We included adults with hypotension, defined as a new vasopressor requirement, systolic blood pressure (SBP) < 90 mm Hg after at least 1 L of crystalloid or 2 units packed red blood cells, or SBP < 90 mm Hg and fluids withheld due to concern for fluid overload. The primary outcome was cardiogenic etiology, adjudicated by two physician chart review, with 25% paired chart review (kappa = 0.92). We used multivariable logistic regression to predict cardiogenic etiology, utilizing clinical data abstracted from the electronic medical record. We created a prediction score from significant covariates and calculated its test characteristics for cardiogenic hypotension.

RESULTS

Of 700 patients with hypotension, 107 (15.3%, 95% CI: 12.6%-18.0%) had cardiogenic etiology. Independent predictors of cardiogenic etiology were shortness of breath (OR 4.1, 95% CI: 2.5-6.7), troponin > 0.1 ng/mL (37.5, 7.1-198.2), electrocardiographic ischemia (8.9, 4.0-19.8), history of heart failure (2.0, 1.1-3.3), and absence of fever (4.5, 2.3-8.7) (area under the curve [AUC] = 0.83). The prediction score created from these predictors yielded 78% sensitivity and 77% specificity for cardiogenic etiology (AUC = 0.827).

CONCLUSIONS

Clinical predictors offer reasonable ED screening sensitivity for cardiogenic hypotension, while demonstrating sufficient specificity to facilitate early cardiac interventions.

The Absence of Fever Is Associated With Higher Mortality and Decreased Antibiotic and IV Fluid Administration in Emergency Department Patients With Suspected Septic Shock

OBJECTIVE

This study evaluates whether emergency department septic shock patients without a fever (reported or measured) receive less IV fluids, have decreased antibiotic administration, and suffer increased in-hospital mortality.

DESIGN

This was a secondary analysis of a prospective, observational study of patients with shock.

SETTING

The study was conducted in an urban, academic emergency department.

PATIENTS

The original study enrolled consecutive adult (aged 18 yr or older) emergency department patients from November 11, 2012, to September 23, 2013, who met one of the following shock criteria: 1) systolic blood pressure less than 90 mm Hg after at least 1L IV fluids, 2) new vasopressor requirement, or 3) systolic blood pressure less than 90 mm Hg and IV fluids held for concern of fluid overload. The current study is limited to patients with septic shock. Patients were grouped as febrile if they had a subjective fever or a measured temperature >100.4°F documented in the emergency department; afebrile patients lacked both.

MEASUREMENTS AND MAIN RESULTS

Among 378 patients with septic shock, 207 of 378 (55%; 50-60%) were febrile by history or measurement. Afebrile patients had lower rates of antibiotic administration in the emergency department (81% vs 94%; p < 0.01), lower mean volumes of IV fluids (2,607 vs 3,013 mL; p < 0.01), and higher in-hospital mortality rates (33% vs 11%; p < 0.01). After adjusting for bicarbonate less than 20 mEq/L, lactate concentration, respiratory rate greater than or equal to 24 breaths/min, emergency department antibiotics, and emergency department IV fluids volume, being afebrile remained a significant predictor of in-hospital mortality (odds ratio, 4.3; 95% CI, 2.2-8.2; area under the curve = 0.83).

CONCLUSIONS

In emergency department patients with septic shock, afebrile patients received lower rates of emergency department antibiotic administration, lower mean IV fluids volume, and suffered higher in-hospital mortality.