Thoughts on the current management of acute aluminum phosphide toxicity and proposals for therapy: An Evidence-based review

Gastrointestinal decontamination using oil-based solutions in patients with acute aluminum phosphide poisoning: a systematic review and meta-analysis

Some studies suggested that gastrointestinal (GIT) decontamination with oil may improve the prognosis of patients who ingested aluminum phosphide (AlP). The aim of this study is to compare the efficacy and safety of gastric lavage with oil-based solutions to any method of gastric decontamination not using oils in patients presenting with acute AlP poisoning. The literature was searched for English-published randomized controlled trials (RCTs) from inception to 16 September 2023. The searched electronic databases included MEDLINE/PubMed, Cochrane Library, Web of Science, Egyptian Knowledge Bank, Scopus, and Google Scholar. Data were extracted and pooled by calculating the risk ratio (RR) for categorical outcomes and standardized mean difference (SMD) for numerical outcomes, with 95% confidence intervals (CI). Seven RCTs were included. Paraffin oil was significantly associated with a lower risk of mortality (RR = 0.59 [95% CI: 0.45, 0.76], p < .001), intubation (RR = 0.59 [95% CI: 0.46, 0.76], p < .001) and vasopressor need (RR = 0.71 [95% CI: 0.56, 0.91], p = .006). Survival time was significantly prolonged with paraffin oil (SMD = 0.72 [95% CI: 0.32, 1.13], p < .001). Coconut oil was significantly associated with prolonged survival time (SMD = 0.83 [95% CI: 0.06, 1.59], p = .03) as well as decreased risk of requiring intubation (RR = 0.78 [95% CI: 0.62, 0.99], p = .04). Oil-based GIT decontamination using paraffin oil showed benefits over conventional lavage regarding the incidence of in-hospital mortality and endotracheal intubation, and survival time. Coconut oil showed some benefits in terms of the intubation incidence and survival time. Decontamination using paraffin oil is recommended. Future clinical trials are warranted with larger sample sizes and focusing on cost-benefit and safety.

The adjuvant effect of oil-based gastric lavage on the outcome of acute Aluminum phosphide poisoning: a systematic review and meta-analysis

Introduction

Aluminum Phosphide (AlP) poisoning constituted the most common cause of poisoning death in some low- and middle-income countries (LMICs). This study aimed to evaluate the safety and efficacy of oil-based gastric lavage (GL) compared with standard therapy for the treatment of AlP poisoning. Materials and methods. This systematic review complied with "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" (PRISMA) Protocols. A comprehensive search was carried out, identifying randomized controlled trials (RCTs), including anyone presenting within 6 h of exposure to AlP, and the administration of GL with oils, including liquid paraffin or coconut oil.

Results

We identified 7 RCTs. The evidence from 4 RCTs indicates that GL with paraffin oil is an effective treatment for acute AlP poisoning, decreasing the mortality rate (RR = 0.62; 95% CI = 0.48 to 0.81; participants = 226; I 2 = 10%; low-quality evidence). We estimate the Number Needed to Treat of 4. Likewise, this intervention reduces the need for intubation and mechanical ventilation (RR = 0.62; 95% CI = 0.40 to 0.79; I2 = 0%; low-quality evidence). Regarding GL with coconut oil, the evidence from 4 RCTs, indicates a slight reduction in mortality (RR = 0.82; 95% CI = 0.69 to 0.98; participants = 112; I2 = 0%; very low-quality evidence).

Conclusions

Limited evidence suggests that GL with paraffin oil is effective in reducing the mortality rate. Likewise, limited evidence showed in favor of paraffin oil concerning the need for intubation and mechanical ventilation. Very limited evidence suggests that GL with coconut oil could reduce mortality. Both interventions would have a benign safety profile.

Cardioprotective role of the coenzyme Q10 and coconut oil in acute aluminum phosphide poisoning: a randomized controlled clinical trial

Aluminum phosphide (ALP)-induced cardiotoxicity is a major cause of high mortality rates. As there is no specific antidote, restoring cardiac hemodynamics is the cornerstone for saving patients. Based on oxidative stress theory in acute ALP poisoning, we examined the cardioprotective role of coconut oil and Coenzyme Q10 (COQ10) in ALP poisoning, focusing on their antioxidant capacity. This study was a randomized, controlled, single-blind, phase II clinical trial conducted at Tanta Poison Control Center over 1 year. Eighty-four ALP poisoned patients received supportive treatment and were randomly allocated to three equal groups. Gastric lavage was performed using sodium bicarbonate 8.4% with saline in group I. Alternatively, group II received 50 ml coconut oil, and group III initially received 600 mg CoQ10 dissolved in 50 ml coconut oil; and repeated 12 hours later. In addition to patient characteristics, clinical, laboratory, electrocardiography (ECG), and total antioxidant capacity (TAC) data were recorded and repeated 12 hours later. Patient outcomes were evaluated. There was no significant difference among groups considering patient characteristics, initial cardiotoxicity severity, vital, laboratory data, ECG changes, and TAC. However, 12 hours post-admissions, group III was significantly improved in all clinical, laboratory, and ECG parameters than comparable groups. Significant correlations were observed between elevated TAC in groups II and III with hemodynamic, serum troponin, and ECG variables. Accordingly, the need for intubation, mechanical ventilation, and the total vasopressor dose was significantly decreased in group III compared with other groups. Therefore, coconut oil and COQ10 are promising cardioprotective adjuvant therapy ameliorating the ALP-induced cardiotoxicity.

Pattern and predictors of death from aluminum and zinc phosphide poisoning using multi-kernel optimized relevance vector machine

The use of metal phosphides, particularly aluminum phosphide, poses a significant threat to human safety and results in high mortality rates. This study aimed to determine mortality patterns and predictive factors for acute zinc and aluminum phosphide poisoning cases that were admitted to Menoufia University Poison and Dependence Control Center from 2017 to 2021. Statistical analysis revealed that poisoning was more common among females (59.7%), aged between 10 and 20 years, and from rural regions. Most cases were students, and most poisonings were the result of suicidal intentions (78.6%). A new hybrid model named Bayesian Optimization-Relevance Vector Machine (BO-RVM) was proposed to forecast fatal poisoning. The model achieved an overall accuracy of 97%, with high positive predictive value (PPV) and negative predictive value (NPV) values of 100% and 96%, respectively. The sensitivity was 89.3%, while the specificity was 100%. The F1 score was 94.3%, indicating a good balance between precision and recall. These results suggest that the model performs well in identifying both positive and negative cases. Additionally, the BO-RVM model has a fast and accurate processing time of 379.9595 s, making it a promising tool for various applications. The study underscores the need for public health policies to restrict the availability and use of phosphides in Egypt and adopt effective treatment methods for phosphide-poisoned patients. Clinical suspicion, positive silver nitrate test for phosphine, and analysis of cholinesterase levels are useful in diagnosing metal phosphide poisoning, which can cause various symptoms.

Refractory cardiogenic shock caused by zinc phosphide toxicity

Zinc phosphide toxicity is a rare entity that presents most frequently among farmers in developing countries who use it as a rodenticide. The phosphine gas released after the ingestion inhibits cytochrome c oxidase, disrupting the mitochondrial physiology and oxidative phosphorylation and causing myocardial stunning. Here we present a case of a 20-year-old man who attempted suicide with zinc phosphide toxicity. Initially, he was hemodynamically stable with a normal ejection fraction; however, in a few hours, he deteriorated quickly and became hemodynamically unstable, with rapid deterioration of his ejection fraction to 20%. He was started on norepinephrine and then dobutamine; however, he had cardiac arrest from refractory cardiogenic shock despite resuscitative measures.

Comparing the effectiveness of L-carnitine and paraffin oil in acute aluminum phosphide poisoning using predictive biomarkers and scores: A randomized controlled clinical trial

Aluminum phosphide (AlP) poisoning is a serious medical emergency with a high mortality rate. The absence of an exact antidote for AlP poisoning necessitates the quest for alternative treatment options. The study sought to assess the efficacy of adding L-carnitine or medicated paraffin oil to the conventional approach of treatment employed in cases of acute AlP poisoning. We conducted a 1 year, randomized, controlled, parallel-group, single-blind clinical study. 96 individuals with acute AlP poisoning were randomly assigned to one of three groups. The standard AlP therapy was administered to all groups according to the Poison Control Center guidelines at the Ain-Shams University hospitals. All patients underwent a medical history review, clinical examination, and laboratory tests. The outcomes were assessed. The participants in the study groups had mean ages ranging from 25.6 to 26.3 years. The cases analyzed were evenly distributed between genders, with the majority originating from rural areas. The average delay time varied from 2.9 to 4.2 h. All patients in the study reported ingesting AlP during suicide attempts. 12 hours after admission, many clinical and biochemical data improved in both intervention groups including cytochrome c oxidase, caspase-3, caspase-9, catalase, and superoxide dismutase. The intervention groups required significantly less mechanical ventilation and had a lower mortality rate than the control group. Decontamination with paraffin oil could be advantageous for reducing the severity of AlP poisoning, improving prognosis, and lowering the mortality rate.

Hopeful News for Physicians Who Involved in the Treatment of Critical Aluminum Phosphide (Rice Pill) Poisoning Patients

Introduction

Aluminum phosphide (rice tablet) was first introduced as a pesticide in India. Rice tablets are commonly used in Iran due to their high efficacy against rodents and insects, low cost, and availability. Aluminum phosphide is a lethal poison without antidote and causes cardiocirculatory collapse and has negative inotropic cardiac effect. Human and animal studies showed that high dose insulin had positive cardiac inotropic effects. GIK (glucose, insulin, and potassium) assists heart uptake of carbohydrates that are the major fuel substrate of the myocard muscle under stressed conditions and leading to correction of acidosis, increased myocardial contractility, and peripheral vascular resistance. Case Presentation. In this manuscript, a young woman with aluminum phosphide poisoning was described to have presented with hypotension, hypoxemia, and severe metabolic acidosis. In contrast to our previous experiences that approximately all rice tablet poisoning patients with shock were dead despite full conservative treatment, this patient miraculously was saved with high dose intravenous regular insulin infusion and was discharged from the hospital with good condition and without any complications.

Conclusion

Rice tablet poisoning has high fatality rate, and to date, no antidote is available. GIK is suggested as a potential life saving treatment for critical rice tablet poisoning patients with symptoms and signs of shock.

Inhibition of mitochondrial permeability transition pore and antioxidant effect of Delta-9-tetrahydrocannabinol reduces aluminium phosphide-induced cytotoxicity and dysfunction of cardiac mitochondria

Previous studies have demonstrated that phosphine gas (PH₃) released from aluminium phosphide (AlP) can inhibit cytochrome oxidase in cardiac mitochondria and induce generation of free radicals, oxidative stress, alteration in antioxidant defense system and cardiotoxicity. Available evidence suggests that cannabinoids have protective effects in the reduction of oxidative stress, mitochondrial and cardiovascular damages. The objective of this study was to evaluate the effect of trans-Δ-9-tetrahydrocannabinol (THC) on AlP-induced toxicity in isolated cardiomyocytes and cardiac mitochondria. Rat heart isolated cardiomyocytes and mitochondria were cotreated with different concentrations of THC (10, 50 and 100 μM) and IC50 of AlP, then cellular and mitochondrial toxicity parameters were assayed. Treatment with AlP alone increased the cytotoxicity, depletion of cellular glutathione (GSH), mitochondrial reactive oxygen species (ROS) generation, lipid oxidation, mitochondria membrane potential (ΔΨm) collapse and mitochondrial swelling, when compared to control group. However, incubation with THC (10, 50 and 100 μM) attenuated the AlP-induced changes in all these parameters in a THC concentration-dependent manner. Interestingly, the obtained results showed remarkably significant protective effects of THC by attenuation the different parameters of cytotoxicity, mitochondrial toxicity and oxidative stress induced by ALP in isolated cardiomyocytes and cardiac mitochondria. It is the first report showing the protective effects of THC against AlP-induced toxicity, and these effects are related to antioxidant potential and inhibition of mitochondria permeability transition (MPT) pore. Based on these results, it was hypothesized that THC may be used as a potential therapeutic agent for the treatment of AlP-induced mitochondrial dysfunction and cardiotoxicity.

Potential role of paraffin oil gastric lavage in acute aluminum phosphide poisoning: a randomized controlled trial

Aluminum phosphide (ALP) poisoning is a true medical emergency associated with high mortality. The lack of a specific antidote for ALP poisoning mandates searching for new treatment modalities. This study aimed to evaluate the effectiveness and safety of gastric decontamination by paraffin oil in cases with acute ALP poisoning. This study was a randomized, controlled, parallel-group, single-blind, phase II clinical trial conducted over a period of 6 months. Sixty-two patients with acute ALP poisoning were randomly allocated into two equivalent groups. In both groups, the standard ALP treatment was given. Gastric decontamination in the control group was performed by saline and sodium bicarbonate 8.4%, while in the intervention group, it was done by paraffin oil and sodium bicarbonate 8.4%. All patients were subjected to history taking, clinical examination, and laboratory investigations. The outcomes were evaluated. The median age of the studied patients was 20 years. Most of the studied cases were females, single, and from rural areas. The median delay time was 1 h. All patients included in the study alleged ingestion of ALP during suicidal attempts. Twelve hours after admission, many clinical and laboratory findings were significantly better in the intervention group. The need for intubation, mechanical ventilation, and total amount of vasopressors was significantly lower, and the mortality rate was non-significantly lower in the intervention group compared to the control. The median length of hospital stay was significantly shorter in the control group. Gastric decontamination with paraffin oil and sodium bicarbonate 8.4% could be valuable in reducing ALP poisoning severity, the need for intubation, mechanical ventilation, and vasopressors.

The Role of Echocardiographic Findings in Estimating Survival Probability of Intensive Care Unit Admitted Aluminum Phosphide Poisoned Patients

INTRODUCTION

Cardiotoxicity represents the primary cause of death in acute aluminum phosphide (AlP) poisoning. Prompt supportive care can improve patient survival. This study assessed the role of echocardiography in estimating the survival probability of AlP-poisoned patients admitted to the intensive care unit.

METHODS

A prospective cohort study of symptomatic acute AlP poisoned patients was conducted between September 2019 and December 2020. Patients were subjected to history taking, clinical examination, To be included, patient evaluation needed to include electrocardiographic (ECG) and echocardiographic studies. The statistical analysis assessed the association between patient survival and relevant factors. Survival analysis was performed using the Kaplan-Meier survival curve and Cox proportional hazard regression.

RESULTS

A total of 90 patients met inclusion criteria. Electrocardiographic abnormalities were detected in 38.1% of survivors and 82.6% of non-survivors (p < 0.001). Survivors had a higher mean left ventricle ejection fraction (LVEF) (50.86 ± 6.30% vs. 26.52 ± 7.64%, respectively, p < 0.001) and a lower percentage of global LV hypokinesia (4.8% vs. 94.2%, p < 0.001). The mean survival time was higher among patients with LVEF ≥ 50% than those with LVEF = 41-49% and ≤ 40% (p = 0.014 and 0.001, respectively). The hazard of death was 4.42 and 5.40 times greater in patients with LVEF ≤ 40% or with global LV hypokinesia, respectively. Regression revealed that the global LV hypokinesia, ECG abnormalities, and decreased LVEF and oxygen saturation were significantly associated with the risk of death (hazard ratios: 4.382, 3.348, 0.957, and 0.971, respectively).

CONCLUSIONS

Echocardiography represents a valuable diagnostic tool to assess cardiac function in acute AlP poisoning. Both LVEF and global LV hypokinesia significantly impact the survival of AlP-poisoned patients. Echocardiography was superior to ECG changes in terms of accuracy for the prediction of mortality.

Transcriptomic Characterization of Inhalation Phosphine Toxicity in Adult Male Sprague-Dawley Rats

Phosphine (PH3) is a highly toxic, corrosive, flammable, heavier-than-air gas that is a commonly used fumigant. When used as a fumigant, PH3 can be released from compressed gas tanks or produced from commercially available metal phosphide tablets. Although the mechanism of toxicity is unclear, PH3 is thought to be a metabolic poison. PH3 exposure induces multiorgan toxicity, and no effective antidotes or therapeutics have been identified. Current medical treatment consists largely of supportive care and maintenance of cardiovascular function. To better characterize the mechanism(s) driving PH3-induced toxicity, we have performed transcriptomic analysis on conscious adult male Sprague-Dawley rats following whole-body inhalation exposure to phosphine gas at various concentration-time products. PH3 exposure induced concentration- and time-dependent changes in gene expression across multiple tissues. These gene expression changes were mapped to pathophysiological responses using molecular pathway analysis. Toxicity pathways indicative of cardiac dysfunction, cardiac arteriopathy, and cardiac enlargement were identified. These cardiotoxic responses were linked to apelin-mediated cardiomyocyte and cardiac fibroblast signaling pathways. Evaluation of gene expression changes in blood revealed alterations in pathways associated with the uptake, transport, and utilization of iron. Altered erythropoietin signaling was also observed in the blood. Upstream regulator analysis identified several therapeutics predicted to counteract PH3-induced gene expression changes. These include antihypertensive drugs (losartan, candesartan, and prazosin) and therapeutics to reduce pathological cardiac remodeling (curcumin and TIMP3). This transcriptomics study has characterized molecular pathways involved in PH3-induced cardiotoxicity. These data will aid in elucidating a precise mechanism of toxicity for PH3 and guide the development of effective medical countermeasures for PH3-induced toxicity.

Human Zinc Phosphide Exposure in Lebanon: A Case Report and Review of the Literature

Introduction

Toxicity from rodenticides such as metal phosphides is common worldwide, particularly in developing countries where consumers have access to unlabeled and uncontrolled insecticides and pesticides.

Case Report

We present the first documentation of a metal phosphide exposure in Lebanon. A middle-aged woman presented to the emergency department following the ingestion of an unknown rodenticide. Spectroscopy analysis of the sample brought by the patient was used and helped identify zinc phosphide. The patient developed mild gastrointestinal symptoms and was admitted to the intensive care unit for observation without further complications.

Review

We subsequently conducted a literature review to understand the diagnosis, pathophysiology, clinical presentation, and management of metal phosphide toxicity. Multiple searches were conducted on MEDLINE and PubMed, and articles related to the topics under discussion were included in the review. Metal phosphide is associated with significant morbidity and mortality involving all body systems. Patients presenting with metal phosphide intoxication need extensive workup including blood testing, electrocardiogram, and chest radiography. To date there is no antidote for metal phosphide toxicity, and management is mostly supportive. Many treatment modalities have been investigated to improve outcomes in patients presenting with metal phosphide toxicities.

Conclusion

Emergency physicians and toxicologists in developing countries need to consider zinc and aluminum phosphides on their differential when dealing with unlabeled rodenticide ingestion. Treatment is mostly supportive with close monitoring for sick patients. Further research is needed to better understand metal phosphide toxicity and to develop better treatment options.

The efficacy of Coenzyme Q10 and liquid paraffin oil in the management of acute aluminum phosphide poisoning

Aluminum phosphide (AlP) poisoning had high morbidities and mortalities with absence of a standardized approach for the treatment. The present study investigated the efficiency of GIT decontamination methods and Coenzyme Q10(Co Q10) (Ubiquinone) in improving the outcome of acute AlP poisoning. A total of 90 patients were included and all patients received immediately supportive measures, then they distributed into three equal groups: In group I, gastric lavage was done using KMNO₄ solution (1:10 000); group II received 250-500 ml liquid paraffin oil orally; group III received 300 mg of Co Q10 dissolved in liquid paraffin. Co Q10 was continued in a dose of 200 mg/day every 12 h. Follow-up blood pressure, arterial blood gases, serum troponin level and need for intubation revealed that the best improvement was in group III followed by group II. The percentage of survivors was 76.67% in group III and 70% of the patients had no residual effects. In group II, the survivors were 63.33%, and 36.67% of the cases discharged without sequelae. The survivors in group I constituted 26.67% and only 16.67% of the patients had no residual effects. GIT decontamination with aqueous solutions in acute AlP poisoning should be avoided. Rapid oral intake of any available oil as a prehospital treatment or immediately on hospital admission could critically improve the outcome of acute AlP poisoning. Besides, the addition of Co Q10 to the oil further improve patients' prognosis. HighlightsAcute aluminum phosphide (AlP) poisoning is associated with high mortalities.The appropriate method of GIT decontamination in acute AlP poisoning is controversy.Conventional gastric lavage was associated with poor prognosis in acute AlP poisoning.GIT decontamination using liquid paraffin oil improved outcome of acute AlP poisoning.Coenzyme Q10 ameliorated AlP toxicity with improvement of cardiac functions.

A study of the predictive factors of mortality in acute poisoning with aluminum phosphide with special reference to echocardiography and SOFA score

Aluminum phosphide (AlP) is considered now one of the most common causes of poisoning among agricultural pesticides. Poisoning with AlP is extremely toxic to humans with high mortality rate. The aim of this work was to evaluate the prognostic factors and outcome of acute aluminum phosphide poisoning in Alexandria Main University Hospital during a period of 6 months from 1 November 2017 until the end of April 2018, highlighting the role of SOFA score and echocardiography in predicting the mortality. The prospective study was conducted on all patients admitted with acute AlP poisoning to Alexandria Main University Hospital for those 6 months. Patients' data were collected in a special sheet and included biosocial data, medical history, poisoning history, complete medical examination, investigations, duration of hospital stay, and the outcome. All patients were assessed according to SOFA score on admission. Thirty patients were admitted during the period of the current study. Females outnumbered males in all age groups with a sex ratio of 2.75:1. The mean age of patients was 22.77 ± 12.79 years. 96.6% of patients came from rural areas. 93.3% of the cases were exposed to poisoning at home, where suicidal poisoning accounted for (86.7%) of cases. 43.3% of patients died (n = 13), and the median value of SOFA score among non-survivors was 10, versus 1 among survivors. The median value of ejection fraction among non-survivors (25%) was half its value in survivors (50%). Although there were many predictors of severity of AlP poisoning, SOFA score was the most predictive factor of mortality detected by multivariate analysis.

Intravascular Hemolysis in Aluminum Phosphide Poisoning

Hemolysis associated with aluminum phosphide poisoning is very rare. Intravascular hemolysis in presence of glucose-6-phosphate dehydrogenase (G6PD) deficiency has been reported rarely in literature. We are reporting a case of young male patient with history of aluminum phosphide poisoning and complicated with intravascular hemolysis without G6PD deficiency. It has been reported only once in the literature.

Extracorporeal membrane oxygenation in aluminum phosphide poisoning in Nepal: a case report

Background

Aluminum phosphide is a very common suicide agent in developing countries like Nepal. Due to the unavailability of a specific antidote, mortality is very high because the phosphine molecule that is formed leads to inhibition of the cytochrome oxidase enzyme system in mitochondria. Extracorporeal membrane oxygenation provides life-saving support to the cardiovascular and respiratory systems until the deadly poison is eliminated from the body.

Case presentation

We encountered one case of 67-year-old Asian woman, a known case of major depressive disorder, who presented to our center with suicidal ingestion of aluminum phosphide with cardiovascular and respiratory dysfunction. On presentation in our emergency room, she had an ejection fraction of 20% and had to be immediately intubated for respiratory failure. Based on the evidence of almost 100% mortality with aluminum phosphide poisoning, extracorporeal membrane oxygenation was initiated in our intensive care unit. Her general condition and hemodynamics gradually improved over the course of 2 days and she was weaned from extracorporeal membrane oxygenation and ventilator by post-extracorporeal membrane oxygenation days 3 and 4, respectively. After psychiatric evaluation and establishment of normal vital parameters, she was moved out of intensive care unit on post-extracorporeal membrane oxygenation day 6 and discharged to home on post-extracorporeal membrane oxygenation day 10.

Conclusions

Although this seems to be a small step in terms of global perspective, it is a giant stride for a developing country. The management of reversible but severe cardiac and respiratory failure certainly opens up newer scopes where we can ensure a quality health care service being made accessible even to the most underprivileged people.