Utility of serum lactate to predict drug-overdose fatality

Serum copeptin, lactate, and shock index as predictors of morbidity and mortality in shocked acutely poisoned patients

BACKGROUND

Poisoning-induced shock is a serious medical emergency with a high mortality rate. Hospitalized poisoned individuals experience multiple adverse cardiovascular events that could progress to cardiac arrest. This study was designed to compare the prognostic role of the admission shock index and plasma copeptin level in shocked poisoned patients and to evaluate their associations with initial patients' characteristics and outcomes.

METHODS

We conducted a prospective study on acutely poisoned adult patients.

RESULTS

A total of 41 patients were enrolled in the study. The mean age of all patients was 27.05 ± 10.99 years and most of the patients were females (n = 27, 66%). Pesticides were the most common type of poisoning (n = 18, 44%), followed by cardiovascular drugs (n = 12, 29.3%). Eleven (26.8%) patients died during the hospital stay length. The initial serum copeptin level and shock index could predict organ dysfunction indexed by sequential organ assessment score (SOFA) with area under the curve (AUCs) of 0.862 and 0.755, respectively. Initial serum copeptin and lactate levels, SOFA score, and their combination can strongly differentiate between survivors and non-survivors with an AUC of 0.944, 0.885, and 0.959, and 0.994, respectively.

CONCLUSION

We concluded that the shock index, serum lactate level, and SOFA score may help in risk stratifying patients and predicting outcomes in critically ill patients with poisoning-induced shock. Copeptin is superior to the shock index in predicting mortality among the studied patients. However, a combination of SOFA score, serum copeptin level, and serum lactate level can develop a more predominant prediction for overall clinical outcomes in these patients.

Management of intoxicated patients – a descriptive outcome analysis of 4,267 ICU patients

Introduction

Intoxications are common in intensive care units (ICUs). The number of causative substances is large, mortality usually low. This retrospective cohort study aims to characterize differences of intoxicated compared to general ICU patients, point out variations according to causative agents, as well as to highlight differences between survivors and non-survivors among intoxicated individuals in a large-scale multi-center analysis.

Methods

A total of 105,998 general ICU patients and 4,267 individuals with the admission diagnoses “overdose” and “drug toxicity” from the years 2014 and 2015 where included from the eICU Collaborative Research Database. In addition to comparing these groups with respect to baseline characteristics, intensive care measures and outcome parameters, differences between survivors and non-survivors from the intoxication group, as well as the individual groups of causative substances were investigated.

Results

Intoxicated patients were younger (median 41 vs. 66 years; p<0.001), more often female (55 vs. 45%; p<0.001), and normal weighted (36% vs. 30%; p<0.001), whereas more obese individuals where observed in the other group (37 vs. 31%; p<0.001). Intoxicated individuals had a significantly lower mortality compared to general ICU patients (1% vs. 10%; aOR 0.07 95%CI 0.05-0.11; p<0.001), a finding which persisted after multivariable adjustment (aOR 0.17 95%CI 0.12-0.24; p<0.001) and persisted in all subgroups. Markers of disease severity (SOFA-score: 3 (1-5) vs. 4 (2-6) pts.; p<0.001) and frequency of vasopressor use (5 vs. 15%; p<0.001) where lower, whereas rates of mechanical ventilation where higher (24 vs. 26%; p<0.001) in intoxicated individuals. There were no differences with regard to renal replacement therapy in the first three days (3 vs. 4%; p=0.26). In sensitivity analysis (interactions for age, sex, ethnicity, hospital category, maximum initial lactate, mechanical ventilation, and vasopressor use), a trend towards lower mortality in intoxicated patients persisted in all subgroups.

Conclusion

This large-scale retrospective analysis indicates a significantly lower mortality of intoxicated individuals compared to general ICU patients.

An analysis of 1344 consecutive acute intoxication cases admitted to an academic emergency medicine department in Turkey

OBJECTIVE:

One of the major causes of emergency department (ED) visits is acute poisoning. Acute intoxications occur soon after either single or multiple exposures to toxic substances, and they started to be a more serious problem in developing countries. The objective of this study was to investigate the local patterns of acute intoxications, as well as clinical and sociodemographic characteristics of patients with acute poisoning, admitted to our hospital’s ED.

METHODS:

This single-center, retrospective study was conducted using medical records of consecutive patients admitted to the ED between January 2016 and December 2017.

RESULTS:

A total of 1344 patients were included in the statistical analysis. Of these, 673 (50.1%) were female. Mean (±SD) age was 32.2 (±12.0), ranging between 17 and 84 years. The highest number of poisoning cases was observed in summer, especially in July (10.0%) and August (11.8%), whereas lowest number of admissions related to poisoning occurred during winter in November (5.1%) and December (5.2%). Among admitted cases, many were suicide attempts (55.7%) followed by non-intentional (accidental) ingestion of non-pharmaceutical (n=553, 41.2%) and pharmaceutical agents (n=42, 3.1%). Single agents were the most common cause of acute intoxications (63.2%) rather than multidrug intoxications. Most frequently observed causes of poisonings were recreational substances (30.0%) and agents exposed by inhalation (13.2%). INR, lactate, and pH levels at admission were significant predictors of 7-day mortality without a significant paired difference between each other. The AUCs for each were 0.89 (SE 0.04; p<0.0001), 0.84 (SE 0.10; p=0.0007), and 0.79 (SE 0.11; p=0.0102), respectively.

CONCLUSION:

We conclude that recreational substances and medicinal drug intoxications were the leading cause of acute poisonings in our region, occurring mostly during the summer.

Prognostic utility of lactate concentrations and kinetics to predict adverse events associated with acute drug overdose

OBJECTIVE

Clinical research on drug intoxication is necessary for appropriate action in emergency departments (EDs). However, currently, there are no evident biomarkers for predicting adverse events (AEs) in patients with drug intoxication. We aimed to evaluate the prognostic value of serum lactate concentrations and lactate kinetics for AEs such as cardiogenic or respiratory failure in patients admitted to the ED with acute drug overdose.

METHODS

We conducted a single-center retrospective study by reviewing the prospective suicide registry of patients visiting the ED. The primary outcome was composite AEs at any point during the ED visit or hospital stay.

RESULTS

A total of 566 patients with acute drug overdose were enrolled in this study. Of these, 62 patients had AEs, whereas 363 patients did not, yielding an AE rate of 14.6%. The median 0 h lactate concentrations in the AE and non-AE groups were 2.7 [2.1-5.1] mmol/L and 2.1 [1.4-2.9] mmol/L, respectively (p < 0.001). The median 6 h lactate concentrations in the AE and non-AE groups were 2.0 [1.5-3.9] mmol/L and 1.3 [0.9-2.2] mmol/L, respectively (p < 0.001). The area under the curve of lactate at 0 h for predicting AEs was 0.705 (95% CI: 0.659-0.748). The optimal lactate cutoff point was 4.2 mmol/L (37.1% sensitivity, 92.8% specificity). Multivariable analysis using a stepwise backward method showed that the 0 h lactate concentration was associated with AEs in acute drug intoxication after adjusting for confounders (adjusted OR of 0 h lactate, 1.47; 95% CI, 1.23-1.77). However, the 6 h lactate concentrations, lactate clearance, and delta lactate levels did not predict the outcomes.

CONCLUSION

Lactate concentrations and kinetics in patients admitted to the ED with an acute drug overdose exhibited limited prognostic utility in predicting AEs and should be interpreted with caution when considered for clinical decision-making.

A predictive model for serious adverse events in adults with acute poisoning in prehospital and hospital care

OBJECTIVE

The objective of this study was to design a risk model with variables determined before hospital arrival to predict the risk of serious adverse events in patients with acute poisoning.

METHODS

A preliminary prospective, multicentre cohort study of adults with prehospital diagnosis of acute intoxication was conducted. The study was carried out in the Public Health System of the Community of Castilla-Leon (Spain), including seven advanced life support units and five hospitals, between April 1, 2018, and June 30, 2019. People aged >18 years with a main prehospital diagnosis of acute poisoning admitted to a referral hospital on advanced life support were included. The main outcome measure was prehospital and hospital serious adverse events in patients with acute poisoning.

RESULTS

We included 221 patients, with a median age of 47 years (interquartile range: 33-61). The most frequent cause of poisoning was psychopharmaceuticals (111 cases, 49.8%): 38 (17.2%) patients had a serious adverse event, with a hospital mortality of 4.1% (nine cases) in the 30 days after the index event. The final model included age ≥65 years (odds ratio [OR]: 9.59, 95% confidence interval [CI]: 3.48-26.45; p < 0.001), oxygen saturation/fraction of inspired oxygen index ≤300 (OR: 15.03, 95% CI: 5.74-39.33; p < 0.001), and point-of-care lactate ≥4 mmol/L (OR: 7.68, 95% CI: 2.88-20.45; p < 0.001). The poisoning Early Warning Score was constructed from these three variables, and 1 point was assigned to each variable. The area under the curve of the score was 0.896 (95% CI: 0.82-0.96; p < 0.001).

CONCLUSIONS

The poisoning Early Warning Score may help in decision-making and promote early identification of high-risk patients with acute poisoning in the prehospital context.

Potential prognostic roles of serum lactate and Creatine kinase levels in poisoned patients

Background

Examination of serum lactate level and its changes, as an indicator of tissue oxygenation, as well as level of creatine kinase (CK) inhibitors, as a factor of mortality which partially expresses heart, brain, and muscle damage, may be considered as tools to determine prognosis in critically ill patients. We aimed to evaluate these two factors as potential prognostic factors in critically poisoned patients admitted to our toxicology ICU.

Method

This is a cross-sectional descriptive-analytic study that was performed on poisoned patients referred to emergency department of Loghman Hakim Hospital. One-hundred critically poisoned patients who had been admitted to ICU were conveniently chosen using a random number table and included into the study after obtaining consent forms from their next of kin. Their serum lactate and CK levels were checked on admission. These levels were compared subsequently between survivors and non-survivors to seek for their potential prognostic role.

Results

In a total of 100 patients enrolled, 61 were male. Serum level of lactate (with a cut off of 26 mg/dL) and serum CK with a cutoff point of 169 U/L could have prognosticated death with sensitivity and specificity of 78 and 77% (for lactate) and 74 and 62% (for serum CK), respectively.

Conclusions

In poisoned patients, serum lactate and CK can be used as possible prognostic factors because they rapidly increase in the serum and are easily detectable.

Diagnosis of acute intoxications in critically ill patients: focus on biomarkers - part 2: markers for specific intoxications

In medical intensive care units, acute intoxications contribute to a large proportion of all patients. Epidemiology and a basic overview on this topic were presented in part one. The purpose of this second part regarding toxicological biomarkers in the ICU setting focuses on specific poisons and toxins. Following the introduction of anion and osmol gap in part one, it's relevance in toxic alcohols and other biomarkers for these poisonings are presented within this publication. Furthermore, the role of markers in the blood, urine and cerebrospinal fluid for several intoxications is evaluated. Specific details are presented, amongst others, for cardiovascular drug poisoning, paracetamol (acetaminophen), ethanol, pesticides, ricin and yew tree intoxications. Detailed biomarkers and therapeutic decision tools are shown for carbon monoxide (CO) and cyanide (CN^-) poisoning. Also, biomarkers in environmental toxicological situations such as mushroom poisoning and scorpion stings are presented.

Diagnosis of acute intoxications in critically ill patients: focus on biomarkers - part 1: epidemiology, methodology and general overview

Acute intoxications account for a significant proportion of the patient population in intensive care units and sedative medications, ethanol, illicit drugs, inhalable poisons and mixed intoxications are the most common causes. The aim of this article is to describe biomarkers for screening and diagnosis of acute intoxications in critically ill patients. For this purpose, a survey of the relevant literature was conducted, and guidelines, case reports, expert assessments, and scientific publications were reviewed. In critical care, it should always be attempted to identify and quantify the poison or toxin with the assistance of enzyme immunoassay (EIA), chromatography, and mass spectrometry techniques and this section is critically appraised in this publication. The principles for anion gap, osmol gap and lactate gap and their usage in intoxications is shown. Basic rules in test methodology and pre-analytics are reviewed. Biomarkers in general are presented in part one and biomarkers for specific intoxications including ethanol, paracetamol, cardiovascular drugs and many others are presented in part two of these publications.

Prognostic Utility of Initial Lactate in Patients With Acute Drug Overdose: A Validation Cohort

STUDY OBJECTIVE

Previous studies have suggested that the initial emergency department (ED) lactate concentration may be an important prognostic indicator for inhospital mortality from acute drug poisoning. We conduct this cohort study to formally validate the prognostic utility of the initial lactate concentration in a larger, distinct patient population with acute drug overdose.

METHODS

This observational, prospective, cohort study was conducted during 5 years at 2 urban teaching hospitals. Consecutive adult ED patients with acute drug overdose had serum lactate levels tested as part of clinical care. The primary outcome was inpatient fatality. Receiver operating characteristics were plotted to determine optimal cut points, test characteristics, area under the curve, odds ratios, and 95% confidence intervals (CIs).

RESULTS

Of 3,739 patients screened, 1,406 were analyzed (56% women; mean age 43.1 years) and 24 died (1.7%). The difference in mean initial lactate concentration was 5.9 mmol/L (95% CI 3.4 to 8.1 mmol/L) higher in patients who died compared with survivors. The area under the curve for prediction of fatality was 0.85 (95% CI 0.73 to 0.95). The optimal lactate cut point for fatality was greater than or equal to 5.0 (odds ratio 34.2; 95% CI 13.7 to 84.2; 94.7% specificity). Drug classes for which lactate had the highest utility were salicylates, sympathomimetics, acetaminophen, and opioids (all area under the curve ≥0.97); lowest utility was for diuretics and angiotensin-converting enzyme inhibitors.

CONCLUSION

Initial lactate concentration is a useful biomarker for early clinical decisionmaking in ED patients with acute drug overdose. Studies of lactate-tailored management for these patient populations are warranted.

Risk factors for severe respiratory depression from prescription opioid overdose

BACKGROUND AND AIMS

Prescription opioid overdose is a leading cause of injury-related morbidity and mortality in the United States. We aimed to identify characteristics associated with clinical severity in emergency department patients with prescription opioid overdose.

DESIGN

This was a secondary data analysis of adult prescription opioid overdoses from a large prospective cohort of acute overdoses. We examined elements of a typical emergency department evaluation using a multivariable model to determine which characteristics were associated with clinical severity, specifically severe respiratory depression (SRD).

SETTING

This study was conducted at two urban academic emergency departments in New York City, USA.

PARTICIPANTS

Adult patients who presented with acute prescription opioid overdose between 2009 and 2013 were included in the current study. We analyzed 307 patients (mean age = 44.7, 42% female, 2.0% mortality).

MEASUREMENTS

Patient demographics, reported substances ingested, suspected intent for ingesting the substance, vital signs, laboratory data, treatments including antidotes and intubation and outcome of death were recorded by trained research assistants. Intent was categorized into four mutually exclusive categories: suicide, misuse, therapeutic error and undetermined. The primary outcome was SRD, defined as administration of either (a) naloxone or (b) endotracheal intubation (ETI).

FINDINGS

A total of 109 patients suffered SRD with 90 patients receiving naloxone alone, nine ETI alone and 10 both naloxone and ETI. The most common opioids were oxycodone (n = 124) and methadone (n = 116). Mean age was higher in patients with SRD (51.1 versus 41.1, P < 0.001). Opioid misuse was associated with SRD in the multivariable analysis [odds ratio (OR) = 2.07, 95% confidence interval (CI) = 1.21-3.55]. The unadjusted relative risk of SRD was high for fentanyl (83.3% SRD) and lowest for codeine (3.6% SRD).

CONCLUSION

In emergency department patients in the United States with prescription opioid overdose, worse clinical severity was associated with opioid misuse, increased with age and was widely variable, depending on the specific opioid medication involved.

Dramatic resuscitation with Intralipid in an epinephrine unresponsive cardiac arrest following overdose of amitriptyline and propranolol

Amitriptyline and propranolol are life threatening in overdose. The efficacy of intravenous lipid emulsion (ILE) in tricyclic antidepressant and propranolol overdose is unclear. We report a dramatic response to ILE following pulseless electrical activity arrest due to mixed amitriptyline and propranolol overdose.

Development and validation of a risk-prediction nomogram for in-hospital mortality in adults poisoned with drugs and nonpharmaceutical agents: An observational study

Acute poisoning with drugs and nonpharmaceutical agents represents an important challenge in the emergency department (ED).The objective is to create and validate a risk-prediction nomogram for use in the ED to predict the risk of in-hospital mortality in adults from acute poisoning with drugs and nonpharmaceutical agents.This was a prospective cohort study involving adults with acute poisoning from drugs and nonpharmaceutical agents admitted to a tertiary referral center for toxicology between January and December 2015 (derivation cohort) and between January and June 2016 (validation cohort). We used a program to generate nomograms based on binary logistic regression predictive models. We included variables that had significant associations with death. Using regression coefficients, we calculated scores for each variable, and estimated the event probability. Model validation was performed using bootstrap to quantify our modeling strategy and using receiver operator characteristic (ROC) analysis. The nomogram was tested on a separate validation cohort using ROC analysis and goodness-of-fit tests.Data from 315 patients aged 18 to 91 years were analyzed (n = 180 in the derivation cohort; n = 135 in the validation cohort). In the final model, the following variables were significantly associated with mortality: age, laboratory test results (lactate, potassium, MB isoenzyme of creatine kinase), electrocardiogram parameters (QTc interval), and echocardiography findings (E wave velocity deceleration time). Sex was also included to use the same model for men and women. The resulting nomogram showed excellent survival/mortality discrimination (area under the curve [AUC] 0.976, 95% confidence interval [CI] 0.954-0.998, P < 0.0001 for the derivation cohort; AUC 0.957, 95% CI 0.892-1, P < 0.0001 for the validation cohort).This nomogram provides more precise, rapid, and simple risk-analysis information for individual patients acutely exposed to drugs and nonpharmaceutical agents, and accurately estimates the probability of in-hospital death, exclusively using the results of objective tests available in the ED.

Acute salicylate poisoning: risk factors for severe outcome

CONTEXT

Salicylate poisoning remains a significant public health threat with more than 20,000 exposures reported annually in the United States.

OBJECTIVE

We aimed to establish early predictors of severe in-hospital outcomes in Emergency Department patients presenting with acute salicylate poisoning.

METHODS

This was a secondary data analysis of adult salicylate overdoses from a prospective cohort study of acute drug overdoses at two urban university teaching hospitals from 2009 to 2013. Patients were included based on confirmed salicylate ingestion and enrolled consecutively. Demographics, clinical parameters, treatment and disposition were collected from the medical record. Severe outcome was defined as a composite occurrence of acidemia (pH <7.3 or bicarbonate <16 mEq/L), hemodialysis, and/or death.

RESULTS

Out of 1997 overdoses screened, 48 patients met inclusion/exclusion criteria. Patient characteristics were 43.8% male, median age 32 (range 18-87), mean initial salicylate concentration 28.1 mg/dL (SD 26.6), and 20.8% classified as severe outcome. Univariate analysis indicated that age, respiratory rate, lactate, coma, and the presence of co-ingestions were significantly associated with severe outcome, while initial salicylate concentration alone had no association. However, when adjusted for salicylate concentration, only age (OR 1.13; 95% CI 1.02-1.26) and respiratory rate (OR 1.29; 95% CI 1.02-1.63) were independent predictors. Additionally, lactate showed excellent test characteristics to predict severe outcome, with an optimal cutpoint of 2.25 mmol/L (78% sensitivity, 67% specificity).

CONCLUSIONS

In adult Emergency Department patients with acute salicylate poisoning, independent predictors of severe outcome were older age and increased respiratory rate, as well as initial serum lactate, while initial salicylate concentration alone was not predictive.

Trend of blood lactate level in acute aluminum phosphide poisoning

BACKGROUND

Aluminum phosphide (AlP) poisoning is common in the developing countries. There is no specific antidote for the treatment of acute AlP poisoning. Early diagnosis of poisoning and outcome predictors may facilitate treatment decisions. The objective of this study was to determine the trend of blood lactate level in acute AlP poisoning to evaluate its role as a prognostic factor.

METHODS

This was a prospective study on acute AlP intoxicated patients during one year. Demographic data, clinical and laboratory data on admission, and outcome were recorded in a self-made questionnaire. Blood lactate levels were analyzed every two hours for 24 hours.

RESULTS

Thirty-nine (27 male, 12 female) patients were included in the study. The mortality rate was 38.5%. The mean blood pressure, pulse rate, blood pH and serum bicarbonate level were significantly different between the survivors and non-survivors groups. Blood lactate level was significantly higher in the non-survivors group during 8 to 16 hours post ingestion.

CONCLUSION

Blood lactate level could be used as an index of severity of acute AlP poisoning.

Biomarkers, lactate, and clinical scores as outcome predictors in systemic poisons exposures

Acute exposure to systemic poisons represents an important challenge in clinical toxicology. We aimed to analyze the potential role of cardiac biomarkers, routine laboratory tests, and clinical scores as morbidity and in-hospital mortality predictors in patients intoxicated with various systemic poisons. We conducted a prospective study on adults acutely exposed to systemic poisons. We determined the PSS, Glasgow Coma Scale (GCS), and we performed electrocardiogram, laboratory tests, lactate and cardiac biomarkers (which were reassessed 4 h, respectively 6 h later). Of 120 patients included, 45% developed complications, 19.2% had a poor outcome, and 5% died. Multivariate logistic regression sustained lactate (odds ratio (OR) 1.58; confidence interval (CI) 95%: 0.97-2.59; p 0.066), MB isoenzyme of creatine kinase (6h-CKMB; OR 1.08; CI 95%: 1.02-1.16; p 0.018) as predictors for a poor outcome. A GCS < 10 (OR 0.113; CI 95%: 0.019-0.658; p 0.015) and 4h-lactate (OR 4.87; CI 95%: 0.79-29.82; p 0.087) predicted mortality after systemic poisons exposure. Receiver operating characteristic analysis showed that brain natriuretic peptide (area under the curve (AUC), 0.96; CI 95%: 0.92-0.99; p < 0.001), lactate (AUC, 0.91; CI 95%: 0.85-0.97; p < 0.001), and 6h-CKMB have good discriminatory capacity for predicting a poor outcome. In conclusion, these biomarkers, lactate, and GCS can be used to predict morbidity and mortality after systemic poisons exposure.

Routine biological tests in self-poisoning patients: results from an observational prospective multicenter study

CONTEXT

Routine biological tests are frequently ordered in self-poisoning patients, but their clinical relevance is poorly studied.

MATERIALS AND METHODS

This is a prospective multicentric observational study conducted in the emergency departments and intensive care units of 5 university and nonuniversity French hospitals. Adult self-poisoning patients without severely altered vital status on admission were prospectively included.

RESULTS

Routine biological test (serum electrolytes and creatinine, liver enzymes, bilirubin, blood cell count, prothrombin time) ordering and results were analyzed. A total of 1027 patients were enrolled (age, 40.2 ± 14 years; women, 61.5%); no patient died during the hospital stay. Benzodiazepine was suspected in more than 70% of cases; 65% (range, 48%-80%) of patients had at least 1 routine biological test performed. At least 1 abnormal test was registered in 23% of these patients. Three factors were associated with abnormal test results: age older than 40 years, male sex, and poisoning with a drug known to alter routine tests (ie, acetaminophen, NSAIDs, metformine, lithium). Depending on these factors, abnormal results ranged from 14% to 48%. Unexpected severe life-threatening conditions were recorded in 6 patients. Only 3 patients were referred to the intensive care unit solely because of abnormal test results.

CONCLUSION

Routine biological tests are commonly prescribed in nonsevere self-poisoning patients. Abnormal results are frequent but their relevance at bedside remains limited.

Noninvasive End Tidal CO2 Is Unhelpful in the Prediction of Complications in Deliberate Drug Poisoning

STUDY OBJECTIVE

We study the performance of capnometry in the detection of early complications after deliberate drug poisoning.

METHODS

This was a prospective cohort study of self-poisoned adult patients who presented at an emergency department (ED) between April 20, 2012, and May 6, 2014. Patients who ingested at least 1 neurologic or respiratory depressant drug were included. The primary outcome was the predictive value of an end tidal CO2 (etco2) measurement greater than or equal to 50 mm Hg for the detection of early complications defined a priori by hypoxia requiring oxygen greater than or equal to 3 L/min, bradypnea less than or equal to 10 breaths/min, or ICU admission after intubation or antidote administration because of unresponsiveness to pain or respiratory arrest. Consciousness scales and clinical data were recorded at admission and every 30 minutes. Noninvasive etco2 was continuously measured for 2 hours after inclusion unless the patient was admitted to the ICU. Patients and physicians were blinded to etco2 values.

RESULTS

Two hundred one patients were included, 35 of whom exhibited at least 1 complication. An etco2 measurement greater than or equal to 50 mm Hg predicted the onset of a complication, with a sensitivity of 46% (95% confidence interval [CI] 29% to 63%) and a specificity of 80% (95% CI 73% to 86%), leading to a positive predictive value of 33% (95% CI 20% to 48%) and a negative predictive value of 88% (95% CI 81% to 92%). etco2 was less able to predict complications than the Glasgow Coma Scale score at inclusion.

CONCLUSION

Capnometry in isolation does not provide adequate prediction of early complications in self-poisoned patients referred to the ED. A dynamic minute-by-minute assessment of etco2 could be more predictive.

Clinical risk factors for in-hospital adverse cardiovascular events after acute drug overdose

OBJECTIVES

It was recently demonstrated that adverse cardiovascular events (ACVE) complicate a high proportion of hospitalizations for patients with acute drug overdoses. The aim of this study was to derive independent clinical risk factors for ACVE in patients with acute drug overdoses.

METHODS

This prospective cohort study was conducted over 3 years at two urban university hospitals. Patients were adults with acute drug overdoses enrolled from the ED. In-hospital ACVE was defined as any of myocardial injury, shock, ventricular dysrhythmia, or cardiac arrest.

RESULTS

There were 1,562 patients meeting inclusion/exclusion criteria (mean age, 41.8 years; female, 46%; suicidal, 38%). ACVE occurred in 82 (5.7%) patients (myocardial injury, 61; shock, 37; dysrhythmia, 23; cardiac arrests, 22) and there were 18 (1.2%) deaths. On univariate analysis, ACVE risk increased with age, lower serum bicarbonate, prolonged QTc interval, prior cardiac disease, and altered mental status. In a multivariable model adjusting for these factors as well as patient sex and hospital site, independent predictors were: QTc > 500 msec (3.8% prevalence, odds ratio [OR] = 27.6), bicarbonate < 20 mEq/L (5.4% prevalence, OR = 4.4), and prior cardiac disease (7.1% prevalence, OR = 9.5). The derived prediction rule had 51.6% sensitivity, 93.7% specificity, and 97.1% negative predictive value, while presence of two or more risk factors had 90.9% positive predictive value.

CONCLUSIONS

The authors derived independent clinical risk factors for ACVE in patients with acute drug overdose, which should be validated in future studies as a prediction rule in distinct patient populations and clinical settings.

Prognostic use of lactate to predict inpatient mortality in acute gastrointestinal hemorrhage

BACKGROUND

Gastrointestinal hemorrhage (GIH) is a common complaint seen in the emergency department (ED) and carries a small but significant mortality rate. The principal purpose of this investigation was to determine whether an ED venous lactate as part of initial laboratory studies is predictive of mortality in patients admitted to the hospital for GIH.

METHODS

Retrospective cohort study for 6 years at an urban tertiary referral hospital included all ED patients with the charted diagnosis of acute GIH. Serum lactate was drawn at the bedside as part of patient care after arrival to the ED at the discretion of the clinical team. Clinical parameters and inpatient mortality were collected from the medical record. Optimal cut points for lactate were derived using receiver operating characteristics curves and imputed into a multivariable logistic regression model.

RESULTS

Of the 2834 medical records that had GIH diagnoses, 1644 had an ED lactate recorded. A lactate greater than 4 mmol/L conferred a 6.4-fold increased odds of in-hospital mortality (94% specificity, P < .001). Controlling for age, initial hematocrit, and heart rate, every 1-point increase in lactate conferred a 1.4-fold increase in the odds of mortality.

CONCLUSIONS

Elevated initial lactate drawn in the ED can be associated with in-hospital mortality for ED patients with acute GIH. Prospective validation studies are warranted.

Deliberate drug poisoning with slight symptoms on admission: are there predictive factors for intensive care unit referral? A three-year retrospective study

Deliberate drug poisoning leads to 1% of emergency department (ED) admissions. Even if most patients do not exhibit any significant complication, 5% need to be referred to an intensive care unit (ICU). Emergency physicians should distinguish between low- and high-acuity poisoned patients at an early stage to avoid excess morbidity. Our aim was to identify ICU transfer factors in deliberately self-poisoned patients without life-threatening symptoms on admission. We performed a 3-year retrospective observational study in a university hospital. Patients over 18 years of age with a diagnosis of deliberate drug poisoning were included. Clinical and toxicological data were analysed with univariate tests between groups (ED stay versus ICU transfer). Factors associated with ICU admission were then included in a logistic regression analysis. Two thousand five hundred and sixty-five patients were included. 63.2% were women, and median age was 40 (28-49). 142 patients (5.5%) were transferred to ICU. Cardiac drugs [adjusted OR (aOR) = 19.81; 95% confidence interval (95% CI): 7.93-49.50], neuroleptics (aOR = 2.78; 95% CI: 1.55-4.97) and meprobamate (aOR = 2.71; 95% CI: 1.27-5.81) ingestions were significantly linked to ICU admission. A presumed toxic dose ingestion (aOR = 2.27; 95% CI: 1.28-4.02), number of ingested tablets (aOR = 1.01; 95% CI: 1.01-1.02 for each tablet) and delay between ingestion and ED arrival <2 hr (aOR = 2.85; 95%CI: 1.62-5.03) were also factors for ICU referral. The Glasgow Coma Scale was the only clinical feature associated with ICU admission (aOR = 1.57; 95% CI: 1.44-1.70 for each point loss). These results suggest that emergency physicians should pay particular attention to toxicological data on ED admission to distinguish between low- and high-acuity self-poisoned patients.

Pyrethroid poisoning: features and predictors of atypical presentations

BACKGROUND

Although pyrethroids are known for low toxicity to humans, clinical systemic characteristics of pyrethroid poisoning remain undefined. We investigated atypical presentations of pyrethroid poisoning and the predictors, among those readily assessed in the emergency department.

METHODS

59 pyrethroid poisoning cases that were diagnosed and treated at the emergency department of Wonju Severance Christian Hospital from September 2004 to December 2012 were retrospectively reviewed.

RESULTS

Atypical presentations were seen in 22 patients (39.3%). Atypical presentations after pyrethroid poisoning included respiratory failure requiring ventilator care (10 patients, 17.9%), hypotension (systolic blood pressure <90 mm Hg) (6 patients, 10.7%), pneumonia (4 patients, 7.1%), acute kidney injury (6 patients, 10.7%), Glasgow Coma Scale (GCS) <15 (19 patients, 33.9%), seizure (2 patients, 3.6%) and death (2 patients, 3.6%). There were differences between atypical versus typical groups in terms of age (62.1±3.7 vs 51.0±2.9, p=0.020), ingested amounts (300 (IQR 100-338) cc vs 100 (IQR 50-300) cc, p=0.002), and bicarbonate and serum lactate (17.4±1.1 vs 20.5±0.4, p=0.011; and 4.42 (IQR 3.60-7.91) mmol/L vs 3.01 (IQR 2.16-4.73) mmol/L, p=0.010, respectively) in initial arterial blood gas analysis. Predictors of the atypical presentations were ingested amount and serum lactate ((OR 1.004, 95% CI 1.001 to 1.008, p=0.013) and (OR 1.387, CI 1.074 to 1.791, p=0.012), respectively). The optimal points were 250 cc and 3.5 mmol/dL.

CONCLUSIONS

39.3% of pyrethroid poisoned patients had atypical presentations with the most common being respiratory failure requiring ventilator care. Predictors of atypical presentation were ingested amount >250 cc and serum lactate >3.5 mmol/L.

Glasgow coma scale score in the prognosis of acute carbamate insecticide intoxication

OBJECTIVES

Carbamate is a widely used insecticide, and fatality due to carbamate insecticide intoxication has been reported. However, no studies have addressed the factors associated with outcome of patients poisoned by carbamate insecticide. The present study sought to identify the independent factors that could help predict the development of medical complications as a result of carbamate intoxication.

METHODS

Fifty two patients presenting with acute carbamate insecticide ingestion at Chonnam National University Hospital were enrolled in this retrospective observational case series. The morbidities that needed intensive treatment such as hypotension, respiratory failure, and death were regarded as complications. To identify the associated factors to these complications, objective variables that are easily assessed at presentation, such as age, initial Glasgow coma scale (GSC) and corrected QT (QTc) prolongation, were analyzed by univariate and multivariate stepwise logistic regression analyses.

RESULTS

Of the 52 patients, 35 (67.3%) had medical complications within 24 hours after carbamate insecticide intoxication and seven (13.5%) died. Respiratory failure was the most common medical complication. The significant factors determined by univariate analysis were initial GCS, elevated lactate, and QTc prolongation. However, initial GCS (≤13) was the only independent factor determined by multivariate analysis that was associated with serious complications requiring intensive medical treatment.

CONCLUSIONS

Carbamate insecticide intoxication is not a mild disease, as previously thought, having a mortality rate of 13.8% and a morbidity rate of 67.3%. Initial GCS ≤ 13 can be used as a significant factor to identify carbamate insecticide-intoxicated patients who will experience complications.

Lactic acidosis secondary to metformin overdose: a case report

INTRODUCTION

Metformin is a commonly used treatment modality in type 2 diabetes mellitus, with a well documented side effect of lactic acidosis. In the intensive care setting lactate and pH levels are regularly used as a useful predictor of poor prognosis. In this article we highlight how high lactate levels are not an accurate predictor of mortality in deliberate metformin overdose.

CASE PRESENTATION

We present the case of a 70-year-old Caucasian man who took a deliberate metformin overdose of unknown quantity. He had a profound lactic acidosis at presentation with a pH of 6.93 and a lactate level of more than 20mmol/L. These figures would normally correspond with a mortality of more than 80%; however, with appropriate management this patient's condition improved.

CONCLUSION

We provide evidence that the decision to treat severe lactic acidosis in deliberate metformin overdose should not be based on arterial lactate and pH levels, as would be the case in other overdoses. We also demonstrate that appropriate treatment with hemodiafiltration and 8.4% sodium bicarbonate, even in patients with a very high lactate and low pH, can be successful.

Usefulness of the serum lactate concentration for predicting mortality in acute beta-blocker poisoning

CONTEXT

Serum lactate measured in the emergency department was recently assessed as an excellent prognosticator of drug-overdose fatality, with the optimal lactate cutoff point being 3.0 mmol/L. However, lactate's role has never been specifically studied in beta-blocker poisonings.

OBJECTIVE

We aimed to evaluate the ability of lactate concentrations to predict outcome (survival versus death) in beta-blocker poisoning.

METHODS

We conducted an 8-year retrospective study for all symptomatic beta-blocker poisonings admitted to our toxicological intensive care unit (ICU). Serum lactate concentrations were measured in 110 patients and final outcomes of survival or death recorded.

RESULTS

Lactate concentrations were 1.79 mmol/L [0.8-5.6] (median, 10-90% percentiles) and peak values of 1.9 mmol/L [0.9-9.5] (p < 0.0001). Nine patients (8%) died in the ICU. Admission serum lactate concentrations differed significantly between survivors and fatalities (p = 0.0008). Four patients (44% of the non-survivors) died in the ICU despite lactate concentrations lower than 3.0 mmol/L. The diagnostic characteristics of the 3.0 mmol/L selected lactate cutoff point were 55% sensitivity and 80% specificity.

CONCLUSION

Serum lactate elevation in beta-blocker poisoning is relatively mild on admission despite the presence of significant cardiovascular symptoms. Even if raised in severe poisonings and alone correlate well with prognosis, lactate concentration is not an absolute predictor of beta-blocker-overdose fatality.