Aspiration of activated charcoal elicits an increase in lung microvascular permeability

Systematic review on the use of activated charcoal for gastrointestinal decontamination following acute oral overdose

INTRODUCTION

The use of activated charcoal in poisoning remains both a pillar of modern toxicology and a source of debate. Following the publication of the joint position statements on the use of single-dose and multiple-dose activated charcoal by the American Academy of Clinical Toxicology and the European Association of Poison Centres and Clinical Toxicologists, the routine use of activated charcoal declined. Over subsequent years, many new pharmaceuticals became available in modified or alternative-release formulations and additional data on gastric emptying time in poisoning was published, challenging previous assumptions about absorption kinetics. The American Academy of Clinical Toxicology, the European Association of Poison Centres and Clinical Toxicologists and the Asia Pacific Association of Medical Toxicology founded the Clinical Toxicology Recommendations Collaborative to create a framework for evidence-based recommendations for the management of poisoned patients. The activated charcoal workgroup of the Clinical Toxicology Recommendations Collaborative was tasked with reviewing systematically the evidence pertaining to the use of activated charcoal in poisoning in order to update the previous recommendations.

OBJECTIVES

The main objective was: Does oral activated charcoal given to adults or children prevent toxicity or improve clinical outcome and survival of poisoned patients compared to those who do not receive charcoal?  Secondary objectives were to evaluate pharmacokinetic outcomes, the role of cathartics, and adverse events to charcoal administration. This systematic review summarizes the available evidence on the efficacy of activated charcoal.

METHODS

A medical librarian created a systematic search strategy for Medline (Ovid), subsequently translated for Embase (via Ovid), CINAHL (via EBSCO), BIOSIS Previews (via Ovid), Web of Science, Scopus, and the Cochrane Library/DARE. All databases were searched from inception to December 31, 2019. There were no language limitations.  One author screened all citations identified in the search based on predefined inclusion/exclusion criteria. Excluded citations were confirmed by an additional author and remaining articles were obtained in full text and evaluated by at least two authors for inclusion. All authors cross-referenced full-text articles to identify articles missed in the searches. Data from included articles were extracted by the authors on a standardized spreadsheet and two authors used the GRADE methodology to independently assess the quality and risk of bias of each included study.

RESULTS

From 22,950 titles originally identified, the final data set consisted of 296 human studies, 118 animal studies, and 145 in vitro studies. Also included were 71 human and two animal studies that reported adverse events. The quality was judged to have a Low or Very Low GRADE in 469 (83%) of the studies. Ninety studies were judged to be of Moderate or High GRADE. The higher GRADE studies reported on the following drugs: paracetamol (acetaminophen), phenobarbital, carbamazepine, cardiac glycosides (digoxin and oleander), ethanol, iron, salicylates, theophylline, tricyclic antidepressants, and valproate. Data on newer pharmaceuticals not reviewed in the previous American Academy of Clinical Toxicology/European Association of Poison Centres and Clinical Toxicologists statements such as quetiapine, olanzapine, citalopram, and Factor Xa inhibitors were included. No studies on the optimal dosing for either single-dose or multiple-dose activated charcoal were found. In the reviewed clinical data, the time of administration of the first dose of charcoal was beyond one hour in 97% (n = 1006 individuals), beyond two hours in 36% (n = 491 individuals), and beyond 12 h in 4% (n = 43 individuals) whereas the timing of the first dose in controlled studies was within one hour of ingestion in 48% (n = 2359 individuals) and beyond two hours in 36% (n = 484) of individuals.

CONCLUSIONS

This systematic review found heterogenous data. The higher GRADE data was focused on a few select poisonings, while studies that addressed patients with unknown and or mixed ingestions were hampered by low rates of clinically meaningful toxicity or death.  Despite these limitations, they reported a benefit of activated charcoal beyond one hour in many clinical scenarios.

The role of iNOS inhibitors on lung injury induced by gastrointestinal decontamination agents aspiration

Aspiration is a devastating complication during decontamination procedure in poisoning patients. We have investigated whether S-methylisothiourea protects different pulmonary aspiration gastrointestinal decontamination agent-induced lung injury in rats. Forty-two male Sprague-Dawley rats were assigned to one of six groups (n = 7): normal saline, activated charcoal, polyethylene glycol, normal saline + S-methylisothiourea treated activated charcoal + S-methylisothiourea treated and polyethylene glycol + S-methylisothiourea treated. Normal saline, activated aharcoal and polyethylene glycol were instilled into the lungs. The rats received S-methylisothiourea i.p twice daily for 7 days. Serum surfactant protein D, oxidative stress products and inducible nitric oxide synthase expression in the lung were investigated. The aspiration of activated charcoal significantly increased all histopathological scores (P < 0.01). Only peribronchial inflammatory cell infiltration, alveolar edema, and alveolar histiocytes were increased in the polyethylene glycol groups as compared to the normal saline group (P < 0.05). Pulmonary aspiration increased serum malondialdehyde (P < 0.001), and surfactant protein D (P < 0.05) levels and decreased serum superoxide dismutase levels (P < 0.05). S-methylisothiourea treatment decreased all histopathological scores in the activated charcoal treated S-methylisothiourea group (P < 0.01) and only decreased alveolar edema and alveolar histiocytes in the polyethylene glycol-treated S-methylisothiourea group (P < 0.05). S-methylisothiourea treatment reduced elevated oxidative factors, inducible nitric oxide synthase activity and serum surfactant protein D levels. Our findings showed that S-methylisothiourea may be a protective drug against Activated Charcoal and Polyethylene Glycol-induced lung injury.

Indications for single-dose activated charcoal administration in acute overdose

PURPOSE OF REVIEW

Gastrointestinal decontamination in overdose patients remains a controversial problem in emergency medicine. There has been a significant decrease in the use of single-dose activated charcoal (SDAC) in recent years based on little new evidence and possibly because the overall mortality in overdose patients is low.

RECENT FINDINGS

Human volunteer studies suggest SDAC is effective and this effect occurs for up to 4 h after ingestion, but the magnitude of the reduction in area under the curve (AUC) decreases over time. Two randomized controlled trials including one recent large study did not find SDAC to be beneficial. Pharmacokinetic and pharmacodynamic studies of specific drugs in overdose suggest that for most drugs SDAC decreases drug exposure, but this does not translate to clinical benefit in all cases. The administration of SDAC is a low-risk intervention.

SUMMARY

Although SDAC is unlikely to be beneficial in many overdose patients, for some subgroups with severe poisoning, the benefits will outweigh the low risk of administration. The use of SDAC should be based on the potential toxicity of the drug ingested and the potential benefit of SDAC balanced against the willingness of the patient to take SDAC and the low risk of administration.

Acute respiratory failure after aspiration of activated charcoal with recurrent deposition and release from an intrapulmonary cavern

OBJECTIVE

To report on the recurrent release of charcoal from an intrapulmonary cavern in a case of acute respiratory failure after charcoal aspiration.

DESIGN

Case report.

SETTING

Anaesthesiological ICU, university hospital.

PATIENT

An 18-year-old ethanol intoxicated comatose patient regurgitated and aspirated activated charcoal during orotracheal intubation.

TREATMENT

After 2 days of mechanical ventilation, the patient was transferred to a tertiary care university hospital. On admission, acute respiratory distress syndrome with bilateral pulmonary infiltrations was diagnosed. The patient's recovery was hampered by recurrent release of charcoal from an intrapulmonary cavern. Sophisticated ventilatory support, prone positioning, secretolytics, repetitive bronchoscopy, and antibiotic therapy may have facilitated bronchoalveolar clearance and weaning after 18 days.

CONCLUSION

Aspiration may be a dramatic complication if charcoal is administered in comatose patients without airway protection. In this case report, advanced intensive care measures were necessary to tackle the special feature of charcoal release from an intrapulmonary cavern.

Gastrointestinal decontamination of the poisoned patient

Gastrointestinal decontamination has been a historically accepted modality in the emergency management of oral intoxicants. Theoretically, gastric and whole-bowel emptying procedures hinder absorption, remove toxic substances, prevent clinical deterioration, and hasten recovery. This article presents a current overview of gastrointestinal decontamination. It challenges the accepted precepts of gut decontamination and assesses the utility of syrup of ipecac-induced emesis, orogastric lavage, single-dose-activated charcoal, cathartics, and whole-bowel irrigation.

Activated charcoal for pediatric poisonings: the universal antidote?

PURPOSE OF REVIEW

For decades, activated charcoal has been used as a 'universal antidote' for the majority of poisons because of its ability to prevent the absorption of most toxic agents from the gastrointestinal tract and enhance the elimination of some agents already absorbed. This manuscript will review the history of activated charcoal, its indications, contraindications, and the complications associated with its use as reported in the literature.

RECENT FINDINGS

Recent randomized prospective studies, although with small numbers, have shown no difference in length of hospital stay, morbidity, and mortality between groups who received and did not receive activated charcoal. No study has had sufficient numbers to satisfactorily address clinical outcome in patients who received activated charcoal less than 1 h following ingestion.

SUMMARY

If used appropriately, activated charcoal has relatively low morbidity. Due to the lack of definitive studies showing a benefit in clinical outcome, it should not be used routinely in ingestions. AC could be considered for patients with an intact airway who present soon after ingestion of a toxic or life-threatening dose of an adsorbable toxin. The appropriate use of activated charcoal should be determined by the analysis of the relative risks and benefits of its use in each specific clinical scenario.

Lung disease 35 years after aspiration of activated charcoal in combination with pulmonary lymphangioleiomyomatosis. A histological and clinicopathological study with scanning electron microscopic evaluation and element analysis

Activated charcoal provides effective treatment for most toxic ingestions. Accidental aspiration of activated charcoal is rare. Previously, there have been a few single cases reported on charcoal-related pulmonary complications. We describe an unusual case of pulmonary lesions 35 years after accidental aspiration of activated charcoal. The 38-year-old female patient presented with recurrent pneumothorax. A routinely performed chest roentgenogram revealed pulmonary lesions, highly suggestive to lymphangioleiomyomatosis (LAM). Histopathological investigation of the lung tissue demonstrated some features of LAM but showed prominent pneumoconiotic lesions with cystic tissue destruction. The pneumoconiotic reaction was characterized by prominent black deposits accompanied by foreign-body granuloma formation and minimal fibrosis. Scanning electron microscopic investigation of these deposits showed particles measuring up to 300 microm in greatest diameter. Energy-dispersive X-ray spectra of these particles revealed carbon-rich material, presumably charcoal. The aspiration event was confirmed by the clinical history. To our knowledge, this is the first report not only on a long-term follow-up after aspiration of activated charcoal but also on charcoal-related pulmonary lesions in combination with LAM.

The Changing Indications of Gastrointestinal Decontamination in Poisonings

Gastrointestinal (GI) decontamination is commonly used in the treatment of the poisoned patient. Although the practice is widely accepted, the science behind the recommendations is limited. This article describes commonly used techniques for GI decontamination and critically reviews the studies evaluating these treatments.

Gastrointestinal decontamination

Overall, no conclusive data support the use of gastric decontamination in the routine management of the poisoned patient. Studies of asymptomatic patients suggest that no treatment is required, and, given the complications that have been reported, this may be a reasonable approach to' most patients. Even in symptomatic patients, the only demonstrable benefit was found in a post-hoc subgroup analysis and involved an outcome of questionable clinical importance. Given these data, it would be easy to conclude that GI decontamination has no role in the management of the poisoned patient. This conclusion is valid when considering poisoned patients as a group, but all poisoned patients are not the same. Patients with trivial ingestion do well without treatment, and their greatest risk is an iatrogenic complication. Even patients with more serious ingestions usually have good outcomes with supportive care alone. It is no longer sufficient to justify GL or forced administration of AC with the supposition that "the patient could have taken something bad." However,there are some overdoses where limiting the systemic absorption of the poison may limit the toxic effects and prevent serious toxicity. After careful consideration of the risks, GI decontamination should be targeted at patients who, in the opinion of the treating physician, have a potentially life-threatening exposure.

Activated charcoal administration in a pediatric emergency department

OBJECTIVES

Activated charcoal is the commonest form of gastrointestinal decontamination offered to potentially poisoned children within United States emergency departments. Our aim was to describe this practice with regard to timing, route of administration, use of flavoring agents, and occurrence of adverse events other than vomiting.

METHODS

Descriptive data were prospectively collected from consecutive administrations of single-dose activated charcoal, within an urban, academic pediatric emergency department, over a period of 2.5 years.

RESULTS

Two hundred seventy-five subjects were enrolled. The median time elapsed between ingestion and emergency department arrival was 1.2 hours. Although 55% of children were administered charcoal within 1 hour of emergency department presentation, only 7.8% received charcoal within 1 hour of poisoning exposure. Forty-four percent of children younger than 6 years, 50% of 6-year to 12-year olds, and 89% of 12-year to 18-year olds drank the charcoal voluntarily (P < 0.01). Medical staff chose not to offer charcoal orally to 42 asymptomatic children among the 176 subjects under the age of 6 years. Of the 114 young children offered oral charcoal, 36 (32%) refused or were intolerant. Nurses added flavoring agents to the charcoal in 59% of oral administrations, but this act did not enhance observed palatability. Among children younger than 6 years, the median time from first sip to complete ingestion of charcoal slurry was 15 minutes. One pulmonary aspiration event and a case of constipation were noted.

CONCLUSIONS

Despite published guidelines, children treated in an emergency department rarely received charcoal within 1 hour of ingestion. Gastric tube administration of charcoal varies by age and is partly subjective in its application. We found no evidence that excipient flavoring of charcoal improved success of administration. Pulmonary aspiration of charcoal, although uncommon, should be considered when assessing the risk of therapy. We offer a report of symptomatic constipation from single-dose charcoal.

Single‐Dose Activated Charcoal‐Backup and Reassess

Single-dose activated charcoal (SDAC) is frequently administered to poisoned patients. The assumption is that toxin absorption is prevented and that toxicity (as defined by morbidity and mortality) of the poisoning is decreased. Yet there is no evidence that SDAC improves outcome. Risks of this procedure have not been determined. The reported adverse events following SDAC administration are reviewed and risk:benefit ratio for this procedure is discussed.

Activated charcoal laryngitis in an intubated patient

Activated charcoal is useful in the management of poisonings, but it is not harmless. We report the case of a patient who developed obstructive laryngitis secondary to aspiration of activated charcoal with a protected airway.

CASE

A 2-year-old girl presented acute mental alteration secondary to presumed poisoning. Mechanical ventilation was initiated, and a single dose of activated charcoal was administered. She had an episode of vomiting during the respiratory weaning. Black-tinted tracheal secretions were suctioned through the tube immediately. Pulmonary auscultation and radiologic examination were normal. When she was extubed, she developed obstructive laryngitis. Fiberbronchoscopy was performed and showed edema and a significant amount of charcoal particles on the epiglottis, arytenoids, and arytenoepiglottic folds. Charcoal particles were removed by bronchoscopy successfully. Later evolution was normal, and no symptoms were present when she was discharged at home.

COMMENTS

Obstructive laryngitis is a new major complication of activated charcoals use in upper airway. It is remarkable that this complication occurred in a protected airway. Charcoal is not an innocuous agent. This case shows that nasogastric administration of activated charcoals presents a significant degree of risk.

Pressure-controlled ventilation attenuates lung microvascular injury in a rat model of activated charcoal aspiration

BACKGROUND

Previous animal data suggest that aspiration of activated charcoal is associated with pulmonary microvascular injury that may be related to excessive ventilator-induced airway pressures. The purpose of this study was to test the hypothesis that ventilator-induced airway trauma contributes to the lung vascular injury observed following activated charcoal aspiration.

METHODS

Capillary filtration coefficient (Kf,c), a sensitive measure of lung microvascular permeability, was determined isogravimetrically prior to and after intratracheal instillation of 0.4 ml/kg (12% weight/vol. solution, pH 7.4) activated charcoal oran equal volume of sterile water in isolated, perfused rat lungs in which ventilation was either pressure-controlled at 10cm H2O or volume-controlled at 5 ml/kg.

RESULTS

There was significant lung injury in both activated charcoal groups regardless of ventilation method compared to control lungs or lungs administered sterile water (p < 0.05 ANOVA). However, injury to pressure-controlled ventilated lungs was significantly less than lungs ventilated with traditional, volume-controlled ventilation.

CONCLUSION

The results of this investigation demonstrate that pressure-controlled ventilation reduces the lung microvascular injury observed following aspiration of activated charcoal as compared to traditional volume-controlled ventilation methods.

Chronic lung disease after activated charcoal aspiration

The ingestion of toxic substances is a common pediatric emergency. Activated charcoal is part of the standard treatment for most toxic ingestions and is considered a benign therapy. We report a case of inadvertent administration of activated charcoal into the trachea that resulted in the development of chronic lung disease.

The role of activated charcoal and gastric emptying in gastrointestinal decontamination: a state-of-the-art review

Gastrointestinal decontamination has been practiced for hundreds of years; however, only in the past few years have data emerged that demonstrate a clinical benefit in some patients. Because most potentially toxic ingestions involve agents that are not toxic in the quantity consumed, the exact circumstances in which decontamination is beneficial and which methods are most beneficial in those circumstances remain important topics of research. Maximum benefit from decontamination is expected in patients who present soon after the ingestion. Unfortunately, many overdose patients present at least 2 hours after taking a medication, when most of the toxin has been absorbed or has moved well into the intestine, beyond the expected reach of gastrointestinal decontamination. Decontamination probably does not contribute to the outcome of many such patients, especially those without symptoms. However, if absorption has been delayed or gastrointestinal motility has been slowed, activated charcoal may reduce the final amount absorbed. The use of activated charcoal in these cases may be beneficial and is associated with few complications. Therefore, administration of activated charcoal is recommended as soon as possible after emergency department presentation, unless the agent and quantity are known to be nontoxic, the agent is known not to adsorb to activated charcoal, or the delay has been so long that absorption is probably complete. The use of gastric emptying in addition to activated charcoal has generated intense debate. Several large comparative studies have failed to demonstrate a benefit of gastric emptying before activated charcoal. Because complications of such 2-step decontamination include a higher rate of intubation, aspiration, and ICU admission, gastric emptying in addition to activated charcoal cannot be considered the routine approach to patients. However, there are several infrequent circumstances in which the data are inadequate to accurately assess the potential benefit of gastric emptying in addition to activated charcoal: symptomatic patients presenting in the first hour after ingestion, symptomatic patients who have ingested agents that slow gastrointestinal motility, patients taking sustained release medications, and those taking massive or life-threatening amounts of medication. These circumstances represent only a small subset of ingestions. In the absence of convincing data about benefit or lack of benefit of gastric emptying for these patients, individual physicians must act on a personal valuation: Is it better to use a treatment that might have some benefit but definitely has some risk or not to use a treatment that has any risk unless there is proven benefit?

Severe respiratory failure following charcoal application in a toddler

Charcoal has been commonly used for enteral detoxication with few adverse effects. In toddlers charcoal can often be simply applied via a gastric tube. Regurgitation and aspiration is considered a rare event. We report the case of a 19-month-old boy who suffered endobronchial charcoal contamination followed by acute airway obstruction and severe respiratory failure despite a commonly used tube placement verification technique. Immediate intubation, tracheal suctioning, intravenous bronchodilators, and high frequency oscillatory ventilation (HFOV) were used to control hypercarbia and hypoxia. Eventually charcoal removal by bronchoscopy was successful. Chest X-ray investigation did not reflect the true amount of charcoal deposited endobronchially at any time. We conclude that gastric tube application of charcoal in children carries a risk of aspiration. This may lead to life-threatening respiratory failure with the need to provide artificial ventilation and bronchial lavage.

Esophageal laceration and charcoal mediastinum complicating gastric lavage

A 19-year-old woman underwent multiple attempts at orogastric lavage before success 5 h after ingesting approximately 24 grams of ibuprofen in a suicide attempt. Activated charcoal was administered via the lavage tube. She vomited charcoal shortly after administration and began experiencing difficulty breathing and an increase in the pitch of her voice. A chest X-ray study showed a widened mediastinum, pneumopericardium, and subcutaneous emphysema consistent with esophageal perforation that was confirmed by computed tomography scan. Surgical exploration revealed a tear in the proximal posterior esophagus with charcoal in the posterior mediastinum. She remained intubated for 7 days and was discharged 14 days after admission. This is a report of esophageal perforation with activated charcoal contamination of the mediastinum after gastric lavage. The risks and benefits of this procedure should be carefully considered in each patient prior to its use. Awake patients should be cooperative with the procedure to minimize any risk of trauma to the oropharynx or esophagus.

Pulmonary aspiration and lung injury

Lung injury after aspiration, although very rare, is a feared and potentially devastating sequela after anaesthesia. This paper summarizes the most recent studies in aspiration lung injury focusing on its clinical epidemiology, new insights in its pathophysiology and innovative concepts in its prevention and therapy.

Activated charcoal as the sole intervention for treatment after childhood poisoning

Childhood poisonings account for approximately two thirds of all human toxic exposures reported annually to the American Association of Poison Control Centers. Activated charcoal (AC) is the mainstay of decontamination in the emergency department setting. This review focuses on six concepts: 1) description of AC and its method of action, 2) evolution of AC in the gastrointestinal decontamination process, 3) prehospital use of AC, 4) superactivated charcoal, 5) multiple-dose AC, and 6) complications of AC administration. The most recent evolving trends in decontamination of the pediatric patient include trends toward earlier decontamination, either in the home or by paramedics in the field. The newer, "super" activated charcoals, with their greater surface area, may improve compliance of oral administration of AC. Finally, guidelines have been set to limit use of multiple-dose activated charcoal regimens to certain pharmaceuticals only, as well as discouraging cathartic use with charcoal dosing.