A Simple Tool Predicts Mortality in Aluminum Phosphide Self-poisoning

Prognostic value of PGI score compared to poison severity score (PSS) and simplified acute physiology score (SAPS) II as predictors of mortality and other adverse outcomes in acute poisoning with aluminum phosphide

Aluminum phosphide (AlP) poisoning is a life-threatening emergency prevalent in the Middle East region including Egypt. Early prediction of prognosis is critical for initiating the utmost intensive interventions. Though many scoring systems were studied for predicting the prognosis of AlP poisoning, these scores received wide criticism. Complexity and reliability were the main concerns. Therefore, this retrospective cross-sectional study aimed to evaluate the performance of the recently introduced PGI score as a predictor of case fatality, the need for mechanical ventilation and vasopressor therapy in acute AlP poisoning. Moreover, it compares the performance of PGI with the known poison severity score (PSS), and the simplified acute physiology score (SAPS) II. Among 144 exposed patients, we reported a mortality rate of 61.1%. Non-survivors exhibited significantly higher PGI, PSS, and SAPS II than survivors. Though the PGI, PSS, and SAPS II proved their significance as predictors of mortality and, the need for MV and vasopressors, the PGI score showed a significantly higher area under the curve (AUC) as a predictor of MV (AUC = 0.848) compared to PSS (AUC = 0.731) and SAPS II (AUC = 0.749). Additively, PGI of 2 or more was a significant predictor of mortality (AUC = 0.831, sensitivity = 65.9%, and specificity = 89.3 %) and MV (p < 0.001), while PGI of 1 or more was another predictor of vasopressor need (AUC = 0.881, sensitivity = 89.0% and specificity = 79.4%). Given the PGI score's high AUCs across all outcomes, coupled with its balanced sensitivity and specificity, the PGI score could be a simple, and robust tool replacing the PSS and SAPS II for predicting mortality, clinical decision-making including the need for MV and vasopressor therapy in acute AlP exposure. Adopting the PGI score seems substantially useful in managing acute AlP poisoning, notably in resource-restricted countries.

OUP accepted manuscript

Introduction

We recently derived a simplified 3-point PGI score (representing blood pH < 7.25, Glasgow coma scale [GCS] score < 13, and impaired systolic blood pressure [SBP] < 90 mm Hg), which accurately predicted in-hospital case fatality ratio (CFR) in acute aluminum phosphide poisoning. The present study aimed to validate the PGI score and compare it with Acute Physiologic Assessment and Chronic Health Evaluation (APACHE) II score, Sequential Organ Failure Assessment score (SOFA), and Simplified Acute Physiology Score (SAPS) II scores.

Patients and Methods

We performed a prospective cohort study in adult patients with aluminum phosphide ingestion admitted in PGIMER, Chandigarh (India), from April 2013 to August 2014. A univariant analysis detected the association of various baseline variables with CFR. Correlation of the PGI score with SOFA, SAPS-II, and APACHE-II scores was performed using Spearman's correlation (r_s , range -1 to +1) and scatter plots.

Results

Seventy-six patients were enrolled (mean age, 28.3 years; 41 males). CFR was 60.5%. PGI score variables-pH, GCS, and impaired SBP predicted CFR (P-value <0.001). Among patients with a total PGI score of 3 or 2, 100% died, compared with 50% in score 1 and 10.7% in score 0. Baseline PGI, SOFA, SAPS-II, and APACHE-II scores predicted CFR (P-value <0.001). There was a positive correlation between the PGI score and SOFA score (r_s , 0.855), SAPS-II score (r_s , 0.861), and APACHE-II score (r_s , 0.883). The P-value for all r_s values was <0.001.

Conclusion

The PGI score is a validated toxidrome-specific and simplified risk-stratification tool. Validation in other populations is warranted to confirm its routine use.

Unexpected survival after deliberate phosphine gas poisoning: An Australian experience of extracorporeal membrane oxygenation rescue in this setting

Phosphine poisoning is responsible for hundreds of thousands of deaths per year in countries where access to this pesticide is unrestricted. Metal phosphides release phosphine gas on contact with moisture, and ingestion of these tablets most often results in death despite intensive support. A 36-year-old woman presented to a regional hospital after ingesting multiple aluminium phosphide pesticide tablets and rapidly developed severe cardiogenic shock. In this case, serendipitous access to an untested Extracorporeal Membrane Oxygenation (ECMO) service of a regional hospital effected a successful rescue and prevented the predicted death. We discuss the toxicology, management and the evidence for and against using ECMO in this acute poisoning.

Management of Acute Aluminum Phosphide Poisoning: Has Anything Changed?

Due to its easy availability, rapid and severe toxicity, and no specific antidote, aluminum phosphide has emerged as a lethal toxin, commonly used for suicidal intent in agricultural communities. Despite various advances in medicine, this compound's toxicity is poorly understood, and it still has a very high case fatality rate with no definitive treatment options available. This review aims to understand the mechanism of toxicity, clinical toxidrome of acute aluminum phosphide poisoning, and the available therapeutic options, including recent advances. A literature review was performed searching PubMed, EMBASE Ovid, and Cochrane Library, using the following search items: ("aluminum phosphide poisoning" OR "aluminum phosphide poisoning toxicity" OR "aluminum phosphide ingestion") AND ("management" OR "therapy" OR "treatment"). Selected articles were discussed amongst all the authors to shape this review. High case fatality rate and lack of any specific antidote are persisting challenges. Therapeutic measures need to be implemented from all fronts - reducing easy access to the poison, developing less toxic alternatives for use as a pesticide, and more studies directed at developing an effective reversal agent for phosphine. The advent of promising agents like glucose-insulin-potassium infusion and lipid emulsion is a new ray of hope in the complete recovery in this fatal poisoning. The need of the hour is to find an agent that rapidly and effectively reverses aluminum phosphide's toxic effects. Large multicenter controlled trials are required to establish the role of glucose-insulin-potassium and lipid emulsion.