Pseudohyperchloremia and Negative Anion Gap - Think Salicylate!

BACKGROUND: Pseudohyperchloremia results in a very low or negative anion gap. Historically, the most common cause of this artifact was bromide poisoning. Bromide salts have been removed from most medications and bromism has become very uncommon. More recently, the introduction of chloride ion selective sensing electrodes (Cl-ISE) has generated a new cause of pseudohyperchloremia-salicylate poisoning. We describe 5 such patients and quantitate the error generated by this measurement artifact. METHODS: The magnitude of artifactual hyperchloremia generated by high salicylate levels was quantified in 5 patients by measuring chloride concentration with several Cl-ISEs from different manufacturers and with Cl-ISEs of different "ages," and comparing these results to measurements with a chloridometer (coulometric titration), which is free of the salicylate artifact. RESULTS: Cl-ISEs from different manufacturers generated a wide range of artifactual chloride concentration elevation. Furthermore, the same Cl-ISE generated increasingly severe pseudohyperchloremia as it was repeatedly reused over time and "aged." CONCLUSIONS: Salicylate interferes with measurement of the blood chloride concentration when a Cl-ISE is used. The severity of this artifact is related to the salicylate level, the specific Cl-ISE, and the "age" of the electrode. Toxic blood salicylate levels can generate marked pseudohyperchloremia, and consequently, an artifactual very small or negative anion gap. The large anion gap metabolic acidosis typical of salicylate poisoning is masked by this artifact. Salicylate has become the most common cause of pseudohyperchloremia, and physicians should immediately consider salicylate poisoning whenever the combination of hyperchloremia and a very small or negative anion gap is reported by the laboratory.

Suicide-related over-the-counter analgesic exposures reported to United States poison control centers, 2000-2018.

PURPOSE: To investigate suicide-related over-the-counter (OTC) analgesic medication exposures among individuals ≥6 years old reported to United States (US) poison control centers. METHODS: Data from the National Poison Data System for the years 2000-2018 were retrospectively analyzed. RESULTS: From 2000 to 2018, US poison control centers recorded 549 807 suicide-related cases involving OTC analgesics, including 327 781 cases (59.6%) admitted to the hospital and 1745 deaths (0.3%). Most cases involved a single substance (67.5%) and occurred among females (72.7%) and individuals 6-19 years old (49.7%). Overall, the rate of exposures increased significantly by 33.5% from 2000 to 2018, primarily driven by the increasing exposure rate among 6- to 19-year-old females. From 2000 to 2018, exposure rates for acetaminophen and ibuprofen increased, while that for acetylsalicylic acid decreased. Additionally, the proportion of cases resulting in a serious medical outcome or healthcare facility admission increased for all types of OTC analgesics. Acetaminophen and acetylsalicylic acid accounted for 48.0% and 18.5% of cases, respectively, and 64.5% and 32.6% of deaths, respectively. Both acetaminophen and acetylsalicylic acid had greater odds of healthcare facility admission (ORs 2.56 and 2.63, respectively) and serious medical outcomes (ORs 2.54 and 4.90, respectively) compared with ibuprofen. CONCLUSIONS: The rate of suicide-related OTC analgesic cases is increasing. Acetaminophen and acetylsalicylic acid cases are associated with greater morbidity and mortality. Prevention efforts should include implementing unit-dose packaging requirements and restrictions on package sizes and purchase quantities for acetaminophen and acetylsalicylic acid products to reduce access to large quantities of these analgesics.

Acetaminophen and Acetylsalicylic Acid Exposure in a Preterm Infant after Maternal Overdose.

Here, we review the case of a 26 1/7 weeks' gestation premature female infant born to a mother who intentionally ingested a large quantity of Tylenol, aspirin, quetiapine, and prenatal vitamins. The neonate subsequently had markedly elevated levels of both Tylenol and aspirin when checked on the first day of life. While overall clinically stable, the neonate did demonstrate coagulopathy as evidenced by abnormal coagulation studies. Both poison control and a pediatric gastroenterologist/hepatologist were consulted. She successfully tolerated a course of N-acetylcysteine; her subsequent Tylenol level was markedly decreased and the neonate exhibited no further effects of toxicity. The salicylate level decreased on its own accord. To our knowledge, this is the first report of a neonate at 26 weeks' gestation that has been successfully managed for supratherapeutic concentrations of acetaminophen and acetylsalicylic acid secondary to maternal ingestion. While rare, this case may serve as a reference for the effectiveness of N-acetylcysteine in premature infants in such instances.

Intoxicación por ácido acetilsalicílico, fisiopatología y manejo / Physiopathology and management of acetylsalicylic acid intoxication

Acetylsalicylic acid (ASA) intoxication is potentially lethal. After ingestion, AAS is rapidly transformed into salicylic acid that dissociates into an hydrogen ion plus salicylate. Salicylate is the main form of AAS in the body and produces multiple alterations. Initially, the stimulation of the ventilatory center promotes a respiratory alkalosis. Then, the mitochondrial dysfunction induced by salicylate, will generate a progressive metabolic acidosis due to the accumulation of ketoacids, lactic acid and dicarboxylic acids among others. Another alterations include hydro electrolytic disorders, gastrointestinal lesions, neurological involvement, ototoxicity and coagulopathy. The correct handling of acetylsalicylic acid intoxication requires an thorough knowledge of its pharmacokinetics and pharmacodynamics. Treatment consists in life support measures, gastric lavage, activated charcoal and urinary alkalization to promote the excretion of salicylates. In some occasions, it will be necessary to start renal replacement therapy as soon as possible.

Metal-Organic Frameworks as Efficient Oral Detoxifying Agents.

Poisoning and accidental oral intoxication are major health problems worldwide. Considering the insufficient efficacy of the currently available detoxification treatments, a pioneering oral detoxifying adsorbent agent based on a single biocompatible metal-organic framework (MOF) is here proposed for the efficient decontamination of drugs commonly implicated in accidental or voluntary poisoning. Furthermore, the in vivo toxicity and biodistribution of a MOF via oral administration have been investigated for the first time. Orally administered upon a salicylate overdose, this MOF is able to reduce the salicylate gastrointestinal absorption and toxicity more than 40-fold (avoiding histological damage) while exhibiting exceptional gastrointestinal stability (<9% degradation), poor intestinal permeation, and safety.

Parachuting psychoactive substances: Pharmacokinetic clues for harm reduction.

BACKGROUND: Parachuting, also called bombing, is a way to ingest psychoactive substances wrapped into cigarette paper, toilet paper, etc. There is little data describing parachuting in terms of substances use, context of use and, most importantly, the motivations for using such wrappers, although some authors hypothesized that parachute could be used for pharmacokinetic reason. However, inconsistently, some authors report that parachutes are used for sustained-release whereas others report that users are looking for an immediate effect. RESEARCH DESIGN AND METHODS: Considering parachute as a "home-made" dosage form, we have applied the dissolution testing to characterize the dissolution performance of a substance wrapped into a parachute and to characterize whether a parachute represents an immediate-release form or not. RESULTS: This in-vitro study provides the first pharmacokinetic data for drugs wrapped in parachutes. It shows that parachute acts as sustained-release form when made with a cigarette paper wrapper, but as immediate release form in the presence of alcohol or if wrapped with toilet paper. CONCLUSIONS: An important message to harm reduction is that users must be aware that a parachute can have unexpected pharmacokinetics and have to avoid taking another parachute in the absence of an immediate-effect to avoid overdose.

Extracorporeal elimination of butalbital in acute aspirin-butalbital-caffeine-codeine (Fiorinal with Codeine) poisoning.

BACKGROUND: Butalbital is a small molecule (approximately 220 Da), with 26% protein binding, a 0.8 L/kg volume of distribution, and is eliminated nearly 80% unchanged in the urine. Although hemodialysis has been used to treat overdoses of other barbiturates, the extracorporeal clearance of butalbital is unknown. The objective of this case is to describe the use of extracorporeal therapy to augment elimination of butalbital after an overdose of aspirin 325 mg-butalbital 50 mg-caffeine 40 mg with codeine 30 mg (Fiorinal with Codeine). METHODS: This is a case report of a single patient. RESULTS: A 67-year-old female was admitted to the medical intensive care unit approximately 3 h after ingestion of 40 tablets of Fiorinal with Codeine. Her presentation was notable for a decline in mental status, preserved renal function and a relatively low peak salicylate concentration at 46.4 mg/dL (3.4 mmol/L). Approximately 8 h after ingestion of 2000 mg of butalbital, our patient's serum concentration was 26.9 mg/L (normal <10 mg/L). At the end of a four-hour hemodialysis session, the total body elimination of butalbital was approximately 60% which corresponded to an intradialytic clearance of 233-300 mL/min. CONCLUSIONS: The extracorporeal clearance of butalbital observed in this case demonstrates the utility of dialysis to augment drug elimination in a Fiorinal with Codeine overdose.

Delayed Salicylate Toxicity in a 17-Year-Old Girl With Initially Undetectable Salicylate Concentration 3.9 Hours After Ingestion.

We report the case of a 17-year-old girl with a 126-mg/kg nonenteric coated aspirin ingestion with nontoxic salicylate concentrations at 1.5 and 3.9 hours postingestion, who developed tinnitus and vomiting an estimated 8 hours postingestion, and who was subsequently found to have a toxic salicylate concentration at 22.7 hours postingestion. This case, as well as previous cases of delayed aspirin therapy, may prompt providers to consider educating patients and their care providers regarding the need to return for further testing if symptoms, such as vomiting or tinnitus, develop after an aspirin ingestion.

Drug Toxicities of Common Analgesic Medications in the Emergency Department.

About 75% of patients present to the emergency department with a complaint of pain. There are multiple prescribed and over-the-counter medications that are available for the treatment of pain. Acetaminophen, opioids, and aspirin are commonly used agents that are available as single agents or in combination with other medications. However, all of these agents are susceptible to toxic overdose, which requires prompt recognition through clinical and laboratory assessment modalities and initiation of therapy to reduce the risk of morbidity and mortality.

Use of continuous renal replacement therapy in salicylate toxicity: A case report and review of the literature.

OBJECTIVE: To report a case of salicylate toxicity treated with continuous venovenous hemodiafiltration (CVVHDF) and review the literature regarding the use of continuous renal replacement therapy (CRRT) for salicylate toxicity. CASE: A 16-year-old male presented after ingesting 1901 mg/kg of enteric coated aspirin. Salicylate level was 92 mg/dl 4 h after ingestion. Sequele included seizure, acute kidney injury, pulmonary edema, and prolonged QTc. He received 5.5 h of hemodialysis followed by CVVHDF to continue to augment clearance. His aspirin level fell to 37.4 mg/dl after HD and then to 11.3 mg/dl after nearly 10 h of CVVHDF. DISCUSSION: Cited reasons for the use of CRRT for salicylate toxicity primarily have been hypotension or desire for ongoing augmentation of salicylate clearance in the setting of multiorgan toxicity. CVVHDF may have a role in severe salicylate toxicity to enhance ongoing clearance after an initial round of HD in order to prevent significant rebound.

Absorption of salicylate powders versus tablets following overdose: a poison center observational study.

BACKGROUND: Salicylate absorption following overdose of aspirin (ASA) tablet formulations can be prolonged for greater than 24 h. Accordingly, serial serum concentrations are typically recommended to guide treatment. However, there are little published data on absorption following ingestion of powder ASA formulations, and it is not known if delayed ASA absorption occurs following overdose of powder formulations. The objective of this study is to compare the absorption characteristics of powder and tablet formulations of ASA in patients reported to a single poison center. METHODS: Electronic records from an accredited poison center were searched for single substance acute or acute on chronic ingestions of ASA in powder form between 1 January 2002 and 31 January 2014. An identical search for ingestions of ASA tablet products between 1 January 2012 and 31 December 2013 was undertaken as the comparator group. Other inclusion criteria were age >12 years, documented time of ingestion, treatment in a health care facility within nine hours of ingestion and at least two detectable serum salicylate concentrations. RESULTS: 16 of 25 powder and 22 of 49 tablet cases met inclusion criteria for analysis. Repeat serum salicylate concentrations following ingestion of tablets increased or insignificantly changed in 11 of 22 (50%) cases, and median serum salicylate concentrations in followed cases remained elevated for up to 12 h in some cases. In comparison, serum salicylate concentrations following powder ingestions declined in 15 of 16 (94%) cases. One patient, who ingested a powder product, underwent hemodialysis pursuant to an initial serum salicylate concentration of 96 mg/dL. CONCLUSIONS: In contrast to persistent concentrations following overdose of tablets, the majority of serum salicylate concentrations declined following ingestion of powder formulations. In this small study population, these findings suggest that prolonged absorption is unlikely following ingestions of ASA powders.

Approach to the Patient With a Negative Anion Gap.

When anion gap calculation generates a very small or negative number, an explanation must be sought. Sporadic (nonreproducible) measurement errors and systematic (reproducible) laboratory errors must be considered. If an error is ruled out, 2 general possibilities exist. A true anion gap reduction can be generated by either reduced concentrations of unmeasured anions such as albumin or increased concentrations of unmeasured cations such as magnesium, calcium, or lithium. This teaching case describes a patient with aspirin (salicylate) poisoning whose anion gap was markedly reduced (-47 mEq/L). The discussion systematically reviews the possibilities and provides the explanation for this unusual laboratory result.

Successful living donor liver transplantation for acute liver failure after acetylsalicylic acid overdose.

A 20-year-old woman was admitted to an emergency hospital after ingesting 66 g of acetylsalicylic acid in a suicide attempt. Although she was treated with gastric lavage, oral activated charcoal, and intravenous hydration with sodium bicarbonate, her hepatic and renal function gradually deteriorated and serum amylase levels increased. Steroid pulse therapy, plasma exchange, and continuous hemodiafiltration did not yield any improvement in her hepatic or renal function, and she was transferred to our hospital for living donor liver transplantation. Nine days after drug ingestion, she developed hepatic encephalopathy: thus, we diagnosed the patient with acute liver failure with hepatic coma accompanied by acute pancreatitis due to the overdose of acetylsalicylic acid. Living donor liver transplantation was immediately performed using a left lobe graft from the patient's mother. Following transplantation, the patient's renal and hepatic function and consciousness improved, and she was discharged. In this report, we describe a rare case of acetylsalicylic acid-induced acute liver failure with acute hepatic coma and concomitant acute pancreatitis and acute renal failure, which were treated successfully with emergency living donor liver transplantation.