Predicting the Occurrence of Hypotension in Stable Patients With Nonvariceal Upper Gastrointestinal Bleeding: Point-of-Care Lactate Testing

Lactate level as a predictor of outcomes in patients with acute upper gastrointestinal bleeding: A systematic review and meta‑analysis

There remains no consensus on the prognostic value of lactate in predicting adverse outcomes such as mortality, rebleeding and higher intensive care unit (ICU) admission rates in patients with upper gastrointestinal bleeding (UGIB). The present study aimed to determine the prognostic accuracy of lactate level in predicting adverse clinical outcomes in patients with acute UGIB. Systematic literature search was conducted in PubMed Central, SCOPUS, EMBASE, MEDLINE, Google Scholar and ScienceDirect databases for studies published up to February 2023. Random-effects model was used for the meta-analysis and the results were presented as pooled standardized mean differences or odds ratio (OR) with 95% confidence interval (CIs). A total of 11 studies were included in the present review. Most of the studies had a high risk of bias. Pooled OR were as follows: 1.39 (95% CI: 1.29-1.51; I2=85%) for the prediction of mortality; 1.29 (95% CI: 1.17-1.42; I2=85.9%) for prediction of ICU admission, 1.14 (95% CI: 1.06-1.23; I2=42.4%) for rebleeding and 2.84 (95% CI: 2.14-3.77; I2=8.1%) for the need of packed red blood cell (pRBC) transfusion. Sensitivity and specificity for the mortality prediction were 72% (95% CI: 57-83%) and 75% (95% CI: 61-85%), respectively, with the area under the curve of 0.79 (95% CI: 0.72-0.85). In conclusion, the results showed that lactate level is a moderately accurate early prediction marker of most adverse clinical outcomes such as mortality, rebleeding, ICU admission and the need for pRBC transfusion in acute UGIB patients.

Construction of a prediction model for rebleeding in patients with acute upper gastrointestinal bleeding

BACKGROUND

The incidence of rebleeding in patients with upper gastrointestinal bleeding (UGIB) remains despite advances in intervention approaches. Therefore, early prediction of the risk of rebleeding could help to greatly reduce the mortality rate in these patients. We aim to develop and validate a new prediction model to predict the probability of rebleeding in patients with AUGIB.

METHODS

A total of 1170 AUGIB patients who completed the procedure of emergency gastroscopy within 48 h of admission were included. Logistic regression analyses were performed to construct a new prediction model. A receiver operating characteristic curve, a line graph, and a calibration and decision curve were used to assess the predictive performance of our new prediction model and compare its performance with that of the AIMS65 scoring system to determine the predictive value of our prediction model.

RESULTS

A new prediction model was constructed based on Lactic acid (LAC), neutrophil percentage (NEUTP), platelet (PLT), albumin (ALB), and D-DIMER. The AUC values and their 95% confidence interval (CI) for the new prediction model and the AIMS65 score were 0.746 and 0.619, respectively, and 0.697-0.795 and 0.567-0.670, respectively. In the training group, the C index values based on the prediction model and the AIMS65 scoring system were 0.720 and 0.610, respectively. In the validation group, the C index values based on the prediction model and the AIMS65 scoring system were 0.828 and 0.667, respectively. The decision and calibration curve analysis also showed that the prediction model was superior to the AIMS65 scoring system in terms of accuracy of prediction, consistency, and net clinical benefit.

CONCLUSION

The prediction model can predict the probability of rebleeding in AUGIB patients after endoscopic hemostasis therapy.

Predictive Role of Admission Venous Lactate Level in Patients with Upper Gastrointestinal Bleeding: A Prospective Observational Study

Upper gastrointestinal bleeding (UGIB) is one of the most common emergencies. Risk stratification is essential in patients with this potentially life-threatening condition. The aim of this prospective study was to evaluate the usefulness of the admission venous lactate level in predicting clinical outcomes in patients with UGIB. All consecutive adult patients hospitalized due to UGIB were included in the study. The clinical data included the demographic characteristics of the observed population, etiology of UGIB, need for surgical intervention and intensive care, bleeding recurrence, and mortality rates. Venous lactate was measured in all patients on admission. Logistic regression analyses were used to calculate the odds ratios (OR) of lactate levels for all outcomes. The receiver operating characteristic (ROC) curve was used to determine the accuracy of lactate levels in measuring clinical outcomes, while Youden index was used to calculate the best cut-off points. A total of 221 patients were included in the study (151M; 70F). There were 24 cases of UGIB recurrence (10.8%), 19 patients (8.6%) required surgery, and 37 individuals (16.7%) required intensive care. Mortality rate was 11.3% (25 cases). The logistic regression analysis showed statistically significant association between admission venous lactate and all clinical outcomes: mortality (OR = 1.39, 95%CI: 1.22–1.58, p < 0.001), recurrence of bleeding (OR = 1.16, 95%CI: 1.06; 1.28, p = 0.002), surgical intervention (OR = 1.17, 95%CI: 1.06–1.3, p = 0.002) and intensive care (OR = 1.33, 95%CI: 1.19–1.5, p < 0.001). The ROC curve analysis showed a high predictive value of lactate levels for all outcomes, especially mortality: cut-off point 4.3 (AUC = 0.82, 95%CI: 0.72–0.92, p < 0.001) and intensive care: cut-off point 4.2 (AUC = 0.76, 95%CI: 0.66–0.85, p < 0.001). Admission venous lactate level may be a useful predictive factor of clinical outcomes in patients with UGIB.

Prediction of Adverse Events in Stable Non-Variceal Gastrointestinal Bleeding Using Machine Learning

Clinical risk-scoring systems are important for identifying patients with upper gastrointestinal bleeding (UGIB) who are at a high risk of hemodynamic instability. We developed an algorithm that predicts adverse events in patients with initially stable non-variceal UGIB using machine learning (ML). Using prospective observational registry, 1439 out of 3363 consecutive patients were enrolled. Primary outcomes included adverse events such as mortality, hypotension, and rebleeding within 7 days. Four machine learning algorithms, namely, logistic regression with regularization (LR), random forest classifier (RF), gradient boosting classifier (GB), and voting classifier (VC), were compared with the Glasgow-Blatchford score (GBS) and Rockall scores. The RF model showed the highest accuracies and significant improvement over conventional methods for predicting mortality (area under the curve: RF 0.917 vs. GBS 0.710), but the performance of the VC model was best in hypotension (VC 0.757 vs. GBS 0.668) and rebleeding within 7 days (VC 0.733 vs. GBS 0.694). Clinically significant variables including blood urea nitrogen, albumin, hemoglobin, platelet, prothrombin time, age, and lactate were identified by the global feature importance analysis. These results suggest that ML models will be useful early predictive tools for identifying high-risk patients with initially stable non-variceal UGIB admitted at an emergency department.

Comparison of risk scores and shock index in hemodynamically stable patients presenting to the emergency department with nonvariceal upper gastrointestinal bleeding

OBJECTIVE

Risk assessment in nonvariceal upper gastrointestinal bleeding (UGIB) is not well validated and remains unclear in hemodynamically stable patients at emergency department admission. We compared the prognostic value of risk-scoring systems for predicting adverse outcomes in patients with nonvariceal UGIB and normotension.

PARTICIPANTS AND METHODS

A single-center prospective observational study was carried out. Patients with consecutive nonvariceal UGIB, presenting with normotension (systolic blood pressure ≥90 mmHg) to the emergency department, were included. We compared the areas under the curves (AUC) of Glasgow Blatchford score (GBS), the pre-endoscopy Rockall score, AIMS65, the shock index, and the modified shock index with respect to adverse outcomes defined as embolization, surgery, ICU admission, rebleeding, and in-hospital mortality.

RESULTS

In total, 1233 patients were included. Adverse outcomes occurred in 165 (13.4%) patients; in-hospital mortality was 1.2%. AUC of the GBS for adverse outcome was higher than that of the shock index, but not significantly different (0.647 vs. 0.569, P=0.23). AUC values of the modified shock index, AIMS65, and the pre-endoscopy Rockall score were 0.565, 0.593, and 0.533, respectively. The cut-off value of the GBS (≥8) was associated with 85% sensitivity and 35% specificity for predicting adverse outcome.

CONCLUSION

Pre-existing risk scores have shown suboptimal predictive ability for adverse events in normotensive patients with nonvariceal UGIB. The GBS (≥8) might help to identify patients prone to adverse events; however, further studies with risk scores or new scores are needed because of the low accuracy of these scores.

Lactic Acid Is an Independent Predictor of Mortality and Improves the Predictive Value of Existing Risk Scores in Patients Presenting With Acute Gastrointestinal Bleeding

Background

There are validated clinical risk scores for risk stratifying patients presenting with acute upper gastrointestinal bleed (GIB), including Glasgow-Blatchford score (GBS), Pre-endoscopic Rockall score (RS-PE) and post-endoscopic complete Rockall Score (RS-C), and AIMS65. Several studies have explored the predictive value of lactic acid (LA) in the context of GI bleeding, but the prognostic role of LA and its incremental value in combination with existing clinical risk scores is not well defined.

Methods

We conducted a retrospective analysis of consecutive patients presenting to the emergency department of a single large academic tertiary care center from January 2014 to December 2015 with a charted diagnosis of acute GIB, inclusive of both upper and lower sources. We evaluated the independent role of LA as well as three clinical risk scores for predicting in-hospital mortality in these patients.

Results

Out of 704 patients admitted with acute GI bleeding, 366 patients had LA measured on presentation to the emergency department. The mean LA level, GBS, RS-PE and RS-C were found to be significantly higher in non-survivors, while there was no difference in the mean AIMS65 score between survivors and non-survivors. A multivariate logistic regression analysis showed that LA level was an independent predictor of in-hospital mortality. The area under the curve (AUC) for the receiver operator characteristic for RS-C, RS-PE, and GBS were 0.742, 0.675, and 0.652, respectively. When integrating LA into the above risk scores, the AUC for RS-C, RS-PE, and GBS showed statistical significance improvements to 0.780 (P = 0.04), 0.774 (P = 0.012), and 0.706 (P = 003), respectively.

Conclusions

In unselected patients with GIB who presented to the emergency department, LA is an independent predictor of in-hospital mortality. Integration of LA into RS-C, RS-PE, and GBS risk scores improved their ability to predict in-hospital mortality. The modified LA-based RS-PE (L-Rockall pre-endoscopic) score demonstrated predictive value comparable to the post-endoscopic RS-C.

Early Risk Score for Predicting Hypotension in Normotensive Patients with Non-Variceal Upper Gastrointestinal Bleedin

Risk assessment for upper gastrointestinal bleeding (UGIB) is important; however, current scoring systems are insufficient. We aimed to develop and validate a prediction model for rapidly determining the occurrence of hypotension in non-variceal UGIB patients with normotension (systolic blood pressure ≥90 mmHg) at emergency department presentation. In this prospective observational cohort study, consecutive non-variceal UGIB patients between January 2012 and April 2017 were enrolled. We developed and validated a new prediction model through logistic regression, with the occurrence of hypotension <24 h as the primary outcome. Among 3363 UGIB patients, 1439 non-variceal UGIB patients were included. The risk factors for the occurrence of hypotension were lactate level, blood in nasogastric tube, and systolic blood pressure. The area under the curve (AUC) of the new scoring model (LBS—Lactate, Blood in nasogastric tube, Systolic blood pressure) in the development cohort was 0.74, higher than the value of 0.64 of the Glasgow–Blatchford score for predicting the occurrence of hypotension. The AUC of the LBS score in the validation cohort was 0.83. An LBS score of ≤2 had a negative predictive value of 99.5% and an LBS score of ≥7 had a specificity of 97.5% in the validation cohort. The new LBS score stratifies normotensive patients with non-variceal UGIB at risk for developing hypotension.

Lactate Parameters Predict Clinical Outcomes in Patients with Nonvariceal Upper Gastrointestinal Bleeding

The predictive role of lactate in patients with nonvariceal upper gastrointestinal bleeding (NVUGIB) has been suggested. This study evaluated several lactate parameters in terms of predicting outcomes of bleeding patients and sought to establish a new scoring model by combining lactate parameters and the AIMS65 score. A total of 114 patients with NVUGIB who underwent serum lactate level testing at least twice and endoscopic hemostasis within 24 hours after admission were retrospectively analyzed. The associations between five lactate parameters and clinical outcomes were evaluated and the predictive power of lactate parameter combined AIMS65s (L-AIMS65s) and AIMS56 scoring was compared. The most common cause of bleeding was gastric ulcer (48.2%). Lactate clearance rate (LCR) was associated with 30-day rebleeding (odds ratio [OR], 0.931; 95% confidence interval [CI], 0.872-0.994; P = 0.033). Initial lactate (OR, 1.313; 95% CI, 1.050-1.643; P = 0.017), maximal lactate (OR, 1.277; 95% CI, 1.037-1.573; P = 0.021), and average lactate (OR, 1.535; 95% CI, 1.137-2.072; P = 0.005) levels were associated with 30-day mortality. Initial lactate (OR, 1.213; 95% CI, 1.027-1.432; P = 0.023), maximal lactate (OR, 1.271; 95% CI, 1.074-1.504; P = 0.005), and average lactate (OR, 1.501; 95% CI, 1.150-1.959; P = 0.003) levels were associated with admission over 7 days. Although L-AIMS65s showed the highest area under the curve for prediction of each outcome, differences between L-AIMS65s and AIMS65 did not reach statistical significance. In conclusion, lactate parameters have a prognostic role in patients with NVUGIB. However, they do not increase the predictive power of AIMS65 when combined.

Care of Acute Gastrointestinal Conditions in the Observation Unit

The Emergency Department Observation Unit (EDOU) provides a viable alternative to inpatient admission for the management of many acute gastrointestinal conditions with additional opportunities of reducing resource utilization and reducing radiation exposure. Using available evidence-based criteria to determine appropriate patient selection, evaluation, and treatment provides higher-quality medical care and improved patient satisfaction. Discussions of factors involved in creating an EDOU capable of caring for acute gastrointestinal conditions and clinical protocol examples of acute appendicitis, gastrointestinal hemorrhage, and acute pancreatitis provide a framework from which a successful EDOU can be built.

Prognostic Factors in Emergency Department Patients with Glyphosate Surfactant Intoxication: Point-of-Care Lactate Testing

An increasing number of suicide attempts involve the ingestion of glyphosate surfactant; hence, clinical toxicologists may encounter severe cases of glyphosate surfactant intoxication. In several other clinical conditions, serum lactate is used to predict outcome. We investigated the relationship between lactate levels and 30-day mortality from glyphosate surfactant poisoning. This retrospective analysis involved 232 patients who were admitted to the emergency department after acute glyphosate surfactant poisoning between January 2004 and June 2014. We used a receiver operating characteristic (ROC) curve to define the optimal cut-off point for lactate levels. A Kaplan-Meier 30-day survival curve was then analysed in terms of the defined cut-off level. We used multi-variate Cox proportional hazards regression analysis to determine the risk factors for 30-day mortality. Of the 232 patients, 29 died, yielding a case fatality rate of 12.5%. Lactate was significantly higher in non-survivors (6.5 ± 3.1 mmol/L) than in survivors (3.3 ± 2.2 mmol/L; p < 0.001), and elevated lactate was significantly associated with 30-day mortality. The area under the ROC curve of lactate levels was 0.836 [95% confidence interval (CI): 0.716-0.869]. Lactate levels higher than 4.7 mmol/L were associated with increased mortality in multi-variable analysis (hazard ratio: 3.2; 95% CI: 1.1-8.7). Besides lactate, age >59 years, corrected QT interval >495 ms and potassium >5.5 mmol/L were independent risk factors for 30-day mortality. Lactate is an independent predictor of 30-day mortality in patients with glyphosate surfactant poisoning. Early measurement of lactate levels may be a simple and practical way to assess the severity of intoxication.