Could machine learning algorithms help us predict massive bleeding at prehospital level?

OBJECTIVE: Comparison of the predictive ability of various machine learning algorithms (MLA) versus traditional prediction scales (TPS) for massive hemorrhage (MH) in patients with severe traumatic injury (STI). DESIGN: On a database of a retrospective cohort with prehospital clinical variables and MH outcome, a treatment of the database was performed to be able to apply the different AML, obtaining a total set of 473 patients (80% training, 20% validation). For modeling, proportional imputation and cross validation were performed. The predictive power was evaluated with the ROC metric and the importance of the variables using the Shapley values. SETTING: Out-of-hospital care of patients with STI. PARTICIPANTS: Patients with STI treated out-of-hospital by a out-of-hospital medical service from January 2010 to December 2015 and transferred to a trauma center in Madrid. INTERVENTIONS: None. MAIN VARIABLES OF INTEREST: Obtaining and comparing the "Receiver Operating Characteristic curve" (ROC curve) metric of four MLAs: "random forest" (RF), "vector support machine" (SVM), "gradient boosting machine" (GBM) and "neural network" (NN) with the results obtained with TPS. RESULTS: The different AML reached ROC values higher than 0.85, having medians close to 0.98. We found no significant differences between AMLs. Each AML offers a different set of more important variables with a predominance of hemodynamic, resuscitation variables and neurological impairment. CONCLUSIONS: MLA may be helpful in patients with HM by outperforming TPS.

Combination of arterial lactate levels and Cv-aCO2/Da-vO2 ratio to predict early allograft dysfunction after liver transplantation.

PURPOSE: We examined the ability of the P(v-a)CO2/Da-vO2 ratio combined with elevated lactate levels to predict early allograft dysfunction (EAD). MATERIALS AND METHODS: Patients were classified into four groups according to lactate levels and P(v-a)CO2/Da-vO2 ratio: Group 1; lactate >2.0 mmol/L and P(v-a)CO2/Da-vO2 ratio >1.0; Group 2; lactate >2.0 mmol/L and P(v-a)CO2/Da-vO2 ratio <1.0; group 3; lactate<2.0 mmol/L and P(v-a)CO2/Da-vO2 ratio >1.0; group 4; lactate<2.0 mmol/L and P(v-a)CO2/Da-vO2 ratio <1.0. We defined EAD according to Olthoff criteria. RESULTS: One-hundred and fifty patients were included. EAD occurred in 41 patients (27.3%), and was associated with worse graft survival at 1 year (92% vs. 73%; P = ,003) as well as a higher re-transplantation rate (4,6% vs. 17,1%; P = ,019). The multivariate analysis revealed that P(v-a)CO2/Da-vO2 ratio at T6 [OR 7.05(CI95% 2.77-19.01, P<.001)] was an independent predictor for EAD. Belonging to group 1 at 6 h was associated with worse clinical outcomes but no association was found with 1-year graft survival or 1-year patient survival. CONCLUSIONS: In this single center, prospective, observational study in patients who received an OLT, we found that elevated lactate levels combined with a high Cv-aCO2/Da-vO2 after 6 h was associated with the development of EAD and worse clinical outcomes in the early postoperative period.

Dexamethasone for the treatment of traumatic brain injured patients with brain contusions and pericontusional edema: Study protocol for a prospective, randomized and double blind trial.

BACKGROUND: Traumatic brain injury (TBI) constitutes a leading cause of death and disability. Patients with TBI and cerebral contusions developing pericontusional edema are occasionally given dexamethasone on the belief that this edema is similar to that of tumors, in which the beneficial effect of dexamethasone has been demonstrated. METHODS: The DEXCON TBI trial is a multicenter, pragmatic, randomized, triple-blind, placebo controlled trial to quantify the effects of dexamethasone on the prognosis of TBI patients with brain contusions and pericontusional edema. Adult patients who fulfill the elegibility criteria will be randomized to dexamethasone/placebo in a short and descending course: 4 mg/6 h (2 days); 4 mg/8 hours (2 days); 2 mg/6 hours (2 days); 2 mg/8 hours (2 days); 1 mg/8 hours (2 days); 1 mg/12 hours (2 days). The primary outcome is the Glasgow Scale Outcome Extended (GOSE) performed 1 month and 6 months after TBI. Secondary outcomes are: number of episodes of neurological deterioration; symptoms associated with TBI; adverse events; volume of pericontusional edema before and after 12 days of treatment; results of the neuropsychological tests one month and 6 months after TBI. The main analysis will be on an "intention-to-treat" basis. Logistic regression will estimate the effect of dexamethasone/placebo on GOSE at one month and at 6 months, dichotomized in unfavorable outcome (GOSE 1-6) and favorable outcome (GOSE 7-8). Efficacy will also be analyzed using the 'sliding dichotomy'. An interim and safety analysis will be performed including patients recruited during the first year to calculate the conditional power. A study with 600 patients would have 80% power (2 sided alpha = 5%) to detect a 12% absolute increase (from 50% to 62%) in good recovery. DISCUSSION: This is a confirmative trial to elucidate the therapeutic efficacy of dexamethasone in a very specific group of TBI patients: patients with brain contusions and pericontusional edema. This trial could become an important milestone for TBI patients as nowadays there is no effective treatment in this type of patients. TRIAL REGISTRATION: eudraCT: 2019-004038-41; Clinical Trials.gov: NCT04303065.

Buffered solutions versus 0.9% saline for resuscitation in critically ill adults and children.

BACKGROUND: Fluid therapy is one of the main interventions provided for critically ill patients, although there is no general consensus regarding the type of solution. Among crystalloid solutions, 0.9% saline is the most commonly administered. Buffered solutions may offer some theoretical advantages (less metabolic acidosis, less electrolyte disturbance), but the clinical relevance of these remains unknown. OBJECTIVES: To assess the effects of buffered solutions versus 0.9% saline for resuscitation in critically ill adults and children. SEARCH METHODS: We searched the following databases to July 2018: CENTRAL, MEDLINE, Embase, CINAHL, and four trials registers. We checked references, conducted backward and forward citation searching of relevant articles, and contacted study authors to identify additional studies. We imposed no language restrictions. SELECTION CRITERIA: We included randomized controlled trials (RCTs) with parallel or cross-over design examining buffered solutions versus intravenous 0.9% saline in a critical care setting (resuscitation or maintenance). We included studies on participants with critical illness (including trauma and burns) or undergoing emergency surgery during critical illness who required intravenous fluid therapy. We included studies of adults and children. We included studies with more than two arms if they fulfilled all of our inclusion criteria. We excluded studies performed in persons undergoing elective surgery and studies with multiple interventions in the same arm. DATA COLLECTION AND ANALYSIS: We used Cochrane's standard methodological procedures. We assessed our intervention effects using random-effects models, but when one or two trials contributed to 75% of randomized participants, we used fixed-effect models. We reported outcomes with 95% confidence intervals (CIs). MAIN RESULTS: We included 21 RCTs (20,213 participants) and identified three ongoing studies. Three RCTs contributed 19,054 participants (94.2%). Four RCTs (402 participants) were conducted among children with severe dehydration and dengue shock syndrome. Fourteen trials reported results on mortality, and nine reported on acute renal injury. Sixteen included trials were conducted in adults, four in the paediatric population, and one trial limited neither minimum or maximum age as an inclusion criterion. Eight studies involving 19,218 participants were rated as high methodological quality (trials with overall low risk of bias according to the domains: allocation concealment, blinding of participants/assessors, incomplete outcome data, and selective reporting), and in the remaining trials, some form of bias was introduced or could not be ruled out.We found no evidence of an effect of buffered solutions on in-hospital mortality (odds ratio (OR) 0.91, 95% CI 0.83 to 1.01; 19,664 participants; 14 studies; high-certainty evidence). Based on a mortality rate of 119 per 1000, buffered solutions could reduce mortality by 21 per 1000 or could increase mortality by 1 per 1000. Similarly, we found no evidence of an effect of buffered solutions on acute renal injury (OR 0.92, 95% CI 0.84 to 1.00; 18,701 participants; 9 studies; low-certainty evidence). Based on a rate of 121 per 1000, buffered solutions could reduce the rate of acute renal injury by 19 per 1000, or result in no difference in the rate of acute renal injury. Buffered solutions did not show an effect on organ system dysfunction (OR 0.80, 95% CI 0.40 to 1.61; 266 participants; 5 studies; very low-certainty evidence). Evidence on the effects of buffered solutions on electrolyte disturbances varied: potassium (mean difference (MD) 0.09, 95% CI -0.10 to 0.27; 158 participants; 4 studies; very low-certainty evidence); chloride (MD -3.02, 95% CI -5.24 to -0.80; 351 participants; 7 studies; very low-certainty evidence); pH (MD 0.04, 95% CI 0.02 to 0.06; 200 participants; 3 studies; very low-certainty evidence); and bicarbonate (MD 2.26, 95% CI 1.25 to 3.27; 344 participants; 6 studies; very low-certainty evidence). AUTHORS' CONCLUSIONS: We found no effect of buffered solutions on preventing in-hospital mortality compared to 0.9% saline solutions in critically ill patients. The certainty of evidence for this finding was high, indicating that further research would detect little or no difference in mortality. The effects of buffered solutions and 0.9% saline solutions on preventing acute kidney injury were similar in this setting. The certainty of evidence for this finding was low, and further research could change this conclusion. Patients treated with buffered solutions showed lower chloride levels, higher levels of bicarbonate, and higher pH. The certainty of evidence for these findings was very low. Future research should further examine patient-centred outcomes such as quality of life. The three ongoing studies once published and assessed may alter the conclusions of the review.

Parenteral irons versus transfused red blood cells for treatment of anemia during canine experimental bacterial pneumonia.

BACKGROUND: No studies have been performed comparing intravenous (IV) iron with transfused red blood cells (RBCs) for treating anemia during infection. In a previous report, transfused older RBCs increased free iron release and mortality in infected animals when compared to fresher cells. We hypothesized that treating anemia during infection with transfused fresh RBCs, with minimal free iron release, would prove superior to IV iron therapy. STUDY DESIGN AND METHODS: Purpose-bred beagles (n = 42) with experimental Staphylococcus aureus pneumonia rendered anemic were randomized to be transfused RBCs stored for 7 days or one of two IV iron preparations (7 mg/kg), iron sucrose, a widely used preparation, or ferumoxytol, a newer formulation that blunts circulating iron levels. RESULTS: Both irons increased the alveolar-arterial oxygen gradient at 24 to 48 hours (p = 0.02-0.001), worsened shock at 16 hours (p = 0.02-0.003, respectively), and reduced survival (transfusion 56%; iron sucrose 8%, p = 0.01; ferumoxytol 9%, p = 0.04). Compared to fresh RBC transfusion, plasma iron measured by non-transferrin-bound iron levels increased with iron sucrose at 7, 10, 13, 16, 24, and 48 hours (p = 0.04 to p < 0.0001) and ferumoxytol at 7, 24, and 48 hours (p = 0.04 to p = 0.004). No significant differences in cardiac filling pressures or performance, hemoglobin (Hb), or cell-free Hb were observed. CONCLUSIONS: During canine experimental bacterial pneumonia, treatment of mild anemia with IV iron significantly increased free iron levels, shock, lung injury, and mortality compared to transfusion of fresh RBCs. This was true for iron preparations that do or do not blunt circulating free iron level elevations. These findings suggest that treatment of anemia with IV iron during infection should be undertaken with caution.

Short- and long-term prognosis of critically-ill patients referred to the ICU from the Emergency Department of a tertiary hospital. / Pronóstico a corto y largo plazo de los pacientes críticos ingresados en la Unidad de Cuidados Intensivos desde el Servicio de Urgencias de un hospital terciario.

BACKGROUND AND OBJECTIVE: A frequent source of critically-ill patients admitted to the ICU is the Emergency Department. It is essential to analyse the short-term prognosis of these patients, but also their evolution after their discharge from the hospital, since this is one of the major concerns of these patients. The aim of this study is to describe the epidemiological characteristics of patients admitted to the ICU from the Emergency Department and to analyse their outcome. PATIENTS AND METHOD: This consisted of an observational prospective cohorts study which included 269 Emergency Department patients consecutively admitted to the ICU over an 18-month period. Factors associated with hospital mortality were presented as an odds ratio (OR) and factors associated with long-term mortality were presented as a hazard ratio (HR). A P-value lower than .05 was accepted as significant. The overall survival was analysed on the basis of the Kaplan-Meier curves. RESULTS: Hospital mortality was 15%, ICU complications where the variables with the greatest impact on short-term mortality: acute renal failure (OR 22.7) and respiratory distress syndrome (OR 51.2). After hospital discharge, the cumulative mortality at 12, 24 and 36 months was 6, 11 and 15%, respectively. The degree of functional dependence (HR 3.7), cancer (HR 3.4) and arrhythmias (HR 2.4) were factors related to long-term mortality. CONCLUSIONS: The short-term outcome of ICU patients is related to age and comorbidity, but more significantly to the characteristics of the acute illness. However, the long-term outcome is more closely associated with the patients' characteristics.