Background: Lactic acidosis is a heterogeneous condition with multiple underlying causes and associated outcomes. The use of multi-dimensional patient data to subtype lactic acidosis can personalize patient care. Machine learning consensus clustering may identify lactic acidosis subgroups with unique clinical profiles and outcomes. Methods: We used the Medical Information Mart for Intensive Care III database to abstract electronic medical record data from patients admitted to intensive care units (ICU) in a tertiary care hospital in the United States. We included patients who developed lactic acidosis (defined as serum lactate ≥ 4 mmol/L) within 48 h of ICU admission. We performed consensus clustering analysis based on patient characteristics, comorbidities, vital signs, organ supports, and laboratory data to identify clinically distinct lactic acidosis subgroups. We calculated standardized mean differences to show key subgroup features. We compared outcomes among subgroups. Results: We identified 1919 patients with lactic acidosis. The algorithm revealed three best unique lactic acidosis subgroups based on patient variables. Cluster 1 (n = 554) was characterized by old age, elective admission to cardiac surgery ICU, vasopressor use, mechanical ventilation use, and higher pH and serum bicarbonate. Cluster 2 (n = 815) was characterized by young age, admission to trauma/surgical ICU with higher blood pressure, lower comorbidity burden, lower severity index, and less vasopressor use. Cluster 3 (n = 550) was characterized by admission to medical ICU, history of liver disease and coagulopathy, acute kidney injury, lower blood pressure, higher comorbidity burden, higher severity index, higher serum lactate, and lower pH and serum bicarbonate. Cluster 3 had the worst outcomes, while cluster 1 had the most favorable outcomes in terms of persistent lactic acidosis and mortality. Conclusions: Consensus clustering analysis synthesized the pattern of clinical and laboratory data to reveal clinically distinct lactic acidosis subgroups with different outcomes.
Machine Learning Prediction Models for Mortality in Intensive Care Unit Patients with Lactic Acidosis
Journal of Clinical Medicine | October 28, 2021 | Volume: 10 | Issue: 21 | Pages: 5021
Background: Lactic acidosis is the most common cause of anion gap metabolic acidosis in the intensive care unit (ICU), associated with poor outcomes including mortality. We sought to compare machine learning (ML) approaches versus logistic regression analysis for prediction of mortality in lactic acidosis patients admitted to the ICU. Methods: We used the Medical Information Mart for Intensive Care (MIMIC-III) database to identify ICU adult patients with lactic acidosis (serum lactate ≥4 mmol/L). The outcome of interest was hospital mortality. We developed prediction models using four ML approaches consisting of random forest (RF), decision tree (DT), extreme gradient boosting (XGBoost), artificial neural network (ANN), and statistical modeling with forward stepwise logistic regression using the testing dataset. We then assessed model performance using area under the receiver operating characteristic curve (AUROC), accuracy, precision, error rate, Matthews correlation coefficient (MCC), F1 score, and assessed model calibration using the Brier score, in the independent testing dataset. Results: Of 1919 lactic acidosis ICU patients, 1535 and 384 were included in the training and testing dataset, respectively. Hospital mortality was 30%. RF had the highest AUROC at 0.83, followed by logistic regression 0.81, XGBoost 0.81, ANN 0.79, and DT 0.71. In addition, RF also had the highest accuracy (0.79), MCC (0.45), F1 score (0.56), and lowest error rate (21.4%). The RF model was the most well-calibrated. The Brier score for RF, DT, XGBoost, ANN, and multivariable logistic regression was 0.15, 0.19, 0.18, 0.19, and 0.16, respectively. The RF model outperformed multivariable logistic regression model, SOFA score (AUROC 0.74), SAP II score (AUROC 0.77), and Charlson score (AUROC 0.69). Conclusion: The ML prediction model using RF algorithm provided the highest predictive performance for hospital mortality among ICU patient with lactic acidosis.
Impact of Palliative Care Services on Treatment and Resource Utilization for Hepatorenal Syndrome in the United States
Background: This study aimed to determine the rates of inpatient palliative care service use and assess the impact of palliative care service use on in-hospital treatments and resource utilization in hospital admissions for hepatorenal syndrome. Methods: Using the National Inpatient Sample, hospital admissions with a primary diagnosis of hepatorenal syndrome were identified from 2003 through 2014. The primary outcome of interest was the temporal trend and predictors of inpatient palliative care service use. Logistic and linear regression was performed to assess the impact of inpatient palliative care service on in-hospital treatments and resource use. Results: Of 5571 hospital admissions for hepatorenal syndrome, palliative care services were used in 748 (13.4%) admissions. There was an increasing trend in the rate of palliative care service use, from 3.3% in 2003 to 21.1% in 2014 (p < 0.001). Older age, more recent year of hospitalization, acute liver failure, alcoholic cirrhosis, and hepatocellular carcinoma were predictive of increased palliative care service use, whereas race other than Caucasian, African American, and Hispanic and chronic kidney disease were predictive of decreased palliative care service use. Although hospital admission with palliative care service use had higher mortality, palliative care service was associated with lower use of invasive mechanical ventilation, blood product transfusion, paracentesis, renal replacement, vasopressor but higher DNR status. Palliative care services reduced mean length of hospital stay and hospitalization cost. Conclusion: Although there was a substantial increase in the use of palliative care service in hospitalizations for hepatorenal syndrome, inpatient palliative care service was still underutilized. The use of palliative care service was associated with reduced resource use.
Acute Kidney Injury after Lung Transplantation: A Systematic Review and Meta-Analysis
Journal of Clinical Medicine | October 17, 2019 | Volume: 8 | Issue: 10 | Pages: 1713
Background: Lung transplantation has been increasingly performed worldwide and is considered an effective therapy for patients with various causes of end-stage lung diseases. We performed a systematic review to assess the incidence and impact of acute kidney injury (AKI) and severe AKI requiring renal replacement therapy (RRT) in patients after lung transplantation. Methods: A literature search was conducted utilizing Ovid MEDLINE, EMBASE, and Cochrane Database from inception through June 2019. We included studies that evaluated the incidence of AKI, severe AKI requiring RRT, and mortality risk of AKI among patients after lung transplantation. Pooled incidence and odds ratios (ORs) with 95% confidence interval (CI) were obtained using random-effects meta-analysis. The protocol for this meta-analysis is registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42019134095). Results: A total of 26 cohort studies with a total of 40,592 patients after lung transplantation were enrolled. Overall, the pooled estimated incidence rates of AKI (by standard AKI definitions) and severe AKI requiring RRT following lung transplantation were 52.5% (95% CI: 45.8–59.1%) and 9.3% (95% CI: 7.6–11.4%). Meta-regression analysis demonstrated that the year of study did not significantly affect the incidence of AKI (p = 0.22) and severe AKI requiring RRT (p = 0.68). The pooled ORs of in-hospital mortality in patients after lung transplantation with AKI and severe AKI requiring RRT were 2.75 (95% CI, 1.18–6.41) and 10.89 (95% CI, 5.03–23.58). At five years, the pooled ORs of mortality among patients after lung transplantation with AKI and severe AKI requiring RRT were 1.47 (95% CI, 1.11–1.94) and 4.79 (95% CI, 3.58–6.40), respectively. Conclusion: The overall estimated incidence rates of AKI and severe AKI requiring RRT in patients after lung transplantation are 52.5% and 9.3%, respectively. Despite advances in therapy, the incidence of AKI in patients after lung transplantation does not seem to have decreased. In addition, AKI after lung transplantation is significantly associated with reduced short-term and long-term survival.
Epidemiology of atrial fibrillation in patients with cirrhosis and clinical significance: a meta-analysis
European Journal of Gastroenterology & Hepatology | November 17, 2018 | Volume: 31 | Issue: 4 | Pages: 514-519
ObjectiveThe epidemiology of atrial fibrillation (AF) in patients with cirrhosis and its clinical significance remain unclear. This study aimed (i) to investigate the pooled prevalence and/or incidence of AF in patients with cirrhosis and (ii) to assess the mortality risk of AF in patients with cirrhosis.Patients and methodsA literature search for studies that reported incidence of AF in patients with cirrhosis was carried out using Medline, Embase, and Cochrane Database from inception through July 2018. Pooled incidence with 95% confidence interval (CI) was calculated using a random-effect model. The protocol for this meta-analysis is registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42018102664).ResultsSeven cohort studies including 385 866 patients with cirrhosis were identified. The pooled estimated prevalence of AF in patients with cirrhosis was 5.0% (95% CI: 2.8–8.6%). When studies that solely assessed patients undergoing transplant evaluation or on transplant waiting list were excluded, the pooled estimated prevalence of AF in patients with cirrhosis was 7.4% (95% CI: 3.5–15.2%). There was a significant association between AF and increased mortality risk in cirrhotic patients with a pooled odds ratio of 1.44 (95% CI: 1.36–1.53).ConclusionThe overall estimated prevalence of AF among patients with cirrhosis is 5.0%. Our study demonstrates a statistically significant increased mortality risk in cirrhotic patients with AF.
Atrial fibrillation following heart transplantation: A systematic review and meta‐analysis of observational studies
Journal of Evidence-Based Medicine | November 16, 2018 | Volume: 11 | Issue: 4 | Pages: 261-271
AbstractObjectivePrevious studies have suggested a high incidence of atrial fibrillation (AF) in heart transplant recipients. However, incidence trends of AF in heart transplant recipients remain unclear. The study's aims were (1) to investigate the pooled incidence/incidence trends of AF following heart transplantation and (2) to assess the mortality risk of heart transplant recipients with AF.MethodsA literature search for studies that reported the incidence of AF following heart transplantation was conducted using MEDLINE, EMBASE, and The Cochrane Database from inception through March 2018. Pooled incidence and odds ratios (OR) with 95%CI were calculated using a random‐effects model.ResultsEighteen studies (2 cohorts from clinical trials and 16 cohort studies) with 5393 heart transplant recipients were enrolled. The pooled estimated incidence of AF in heart transplant was 10.1% (95%CI: 7.6%‐13.2%). Meta‐analysis based on the type of anastomotic technique demonstrated a pooled estimated incidence of AF following heart transplantation of 18.7% (95%CI: 10.3%‐31.5%) and 11.1% (95%CI: 6.5%‐18.4%) by biatrial and bicaval techniques, respectively. There was a significant association between AF following a heart transplant and increased mortality risk with a pooled OR of 2.86 (95%CI: 2.08‐3.93). Meta‐regression analyses showed no significant correlations between the year of study and incidence of AF (P = 0.47) or mortality risk of AF after heart transplantation (P = 0.99).ConclusionsThe overall estimated incidence of AF following heart transplantation is 10.1%. There is a significant association between AF and increased mortality after transplantation. Furthermore, incidence and mortality risk of AF following heart transplant does not seem to decrease over time.
Comparison of renal outcomes in off‐pump
versus
on‐pump coronary artery bypass grafting: A systematic review and meta‐analysis of randomized controlled trials
Abstract Aim The objective of this meta‐analysis was to compare the effects of off‐pump and on‐pump coronary artery bypass grafting ( CABG ) on acute kidney injury ( AKI ) and the need of dialysis after surgery. Methods Comprehensive literature searches for randomized controlled trials ( RCTs ) of CABG with on‐pump and off‐pump was performed using MEDLINE , EMBASE , C ochrane D atabase of S ystematic R eviews, C ochrane C entral R egister of C ontrolled T rials S ystematic R eviews and clinicaltrials.gov from inception through S eptember 2014. Primary outcomes were the incidence of AKI and the need of dialysis. Mortality was assessed among the studies that reported renal outcomes. Pooled risk ratios ( RR s) and 95% confidence interval ( CI ) were calculated using a random‐effect, generic inverse variance method. Results Thirty‐three RCTs with 17 322 patients were enrolled in our study. Patients in the off‐pump CABG group had overall lower incidence of AKI (19.1%) compared with the on‐pump CABG group (22.2%). There was a protective effect of off‐pump CABG on the incidence of AKI compared with the on‐pump CABG group ( RR : 0.87; 95% CI : 0.77–0.98). However, there was no significant difference in the need for dialysis in the off‐pump group compared with the on‐pump group ( RR : 0.84; 95% CI 0.63–1.13). Within the selected trials, post hoc analysis assessing the mortality outcome demonstrated a pooled RR of 0.97 (95% CI , 0.77–1.23) in off‐pump versus on‐pump CABGs . Conclusions Our study demonstrates a beneficial effect of off‐pump CABG on the incidence of AKI . However, our meta‐analysis does not show benefits of the need of dialysis or survival among patients undergoing off‐pump CABG .
Associations of sugar‐sweetened and artificially sweetened soda with chronic kidney disease: A systematic review and meta‐analysis
Abstract Background/Objectives The risk of chronic kidney disease ( CKD ) in patients who regularly drink soda is controversial. The objective of this meta‐analysis was to evaluate the associations between consumption of sugar‐sweetened and artificially sweetened soda and CKD . Methods A literature search was performed using MEDLINE , EMBASE and the C ochrane D atabase of S ystematic R eviews from inception until 30 J une 2014. Studies that reported odds ratios or hazard ratios comparing the risk of CKD in patients consuming significant amounts of either sugar‐sweetened or artificially sweetened soda versus those who did not consume soda were included. Pooled risk ratios ( RR ) and 95% confidence intervals ( CI ) were calculated using a random‐effects, generic inverse variance method. Results Five studies were included in our analysis of the association between consumption of sugar‐sweetened soda and CKD . The pooled RR of CKD in patients consuming sugar‐sweetened soda was 1.58 (95% CI 1.00–2.49). Four studies were selected to assess the association between consumption of artificially sweetened soda and CKD . The pooled RR of CKD in patients consuming artificially sweetened soda was 1.33 (95% CI 0.82–2.15). Conclusions Our study demonstrates statistically significant increased risks of CKD in patients consuming sugar‐sweetened soda, but not in patients consuming artificially sweetened soda. This finding suggests that sugar‐sweetened soda consumption is associated with CKD and may impact clinical management and primary prevention of CKD in high‐risk patients.