Shock Index Correlates with Extravasation on Angiographs of Gastrointestinal Hemorrhage: A Logistics Regression Analysis

Abstract

We applied multivariate analysis to the clinical findings in patients with acute gastrointestinal (GI) hemorrhage and compared the relationship between these findings and angiographic evidence of extravasation. Our study population consisted of 46 patients with acute GI bleeding. They were divided into two groups. In group 1 we retrospectively analyzed 41 angiograms obtained in 29 patients (age range, 25-91 years; average, 71 years). Their clinical findings including the shock index (SI), diastolic blood pressure, hemoglobin, platelet counts, and age, which were quantitatively analyzed. In group 2, consisting of 17 patients (age range, 21-78 years; average, 60 years), we prospectively applied statistical analysis by a logistics regression model to their clinical findings and then assessed 21 angiograms obtained in these patients to determine whether our model was useful for predicting the presence of angiographic evidence of extravasation. On 18 of 41 (43.9%) angiograms in group 1 there was evidence of extravasation; in 3 patients it was demonstrated only by selective angiography. Factors significantly associated with angiographic visualization of extravasation were the SI and patient age. For differentiation between cases with and cases without angiographic evidence of extravasation, the maximum cutoff point was between 0.51 and 0.0.53. Of the 21 angiograms obtained in group 2, 13 (61.9%) showed evidence of extravasation; in 1 patient it was demonstrated only on selective angiograms. We found that in 90% of the cases, the prospective application of our model correctly predicted the angiographically confirmed presence or absence of extravasation. We conclude that in patients with GI hemorrhage, angiographic visualization of extravasation is associated with the pre-embolization SI. Patients with a high SI value should undergo study to facilitate optimal treatment planning.

The Compensatory Reserve For Early and Accurate Prediction Of Hemodynamic Compromise

“…In its evolution, an SI > 0.9 was proposed as an indicator of impending hemorrhagic shock (58,60,61). Indeed, there is compelling evidence suggesting that SI is more sensitive than either HR or SBP alone as an early predictor of hemorrhage (60,62,63), massive transfusion (64), morbidity (58), and mortality in geriatric patients (59,61). Based on the SI threshold of 0.9, doctrine would indicate that Group 2 would be considered at higher risk for developing shock than Group 1.…”

Diagnosis and management of acute lower gastrointestinal bleeding: guidelines from the British Society of Gastroenterology

“…There are few data describing the use of the shock index in LGIB, although the recent NCEPOD report that included LGIB, found that increasing shock index was associated with mortality 5. A shock index of ≥1 can also be used to predict extravasation of contrast on angiography in LGIB21 and therefore may be used to identify patients with active bleeding, who are likely to benefit from CTA. As the shock index reflects simply haemodynamic instability and is easy to calculate, its use is warranted even though there are few studies describing its use in LGIB.…”

Severe Gastrointestinal Haemorrhage: Summary of a National Quality of Care Study with Focus on Radiological Services

“…26% (152/587) had a shock index of >1 suggesting deficiencies in the clinical recognition of haemodynamic compromise. A shock index of one or greater has been shown to be predictive of active bleeding at imaging [9]. …”