The effects of wheat pill poisoning (aluminum phosphide) dosage on arterial blood gases and their clinical outcome

Objective: To analyse the eﬀects of aluminum phosphide poisoning dosage on arterial blood gases and the clinical outcome. Method: The cross-sectional study was conducted at the intensive care unit of Mardan Medical Complex, Mardan, Pakistan, from January 2021 to May 2022, and comprised patients of either gender who had attempted suicide using aluminum phosphide. Data was collected using a predesigned questionnaire. Data was analysed using SPSS 26. Results: Of the 116 patients, 42(36.2%) were males and 74(63.8%) were females. There were 75(64.65) survivors; 31(41.33) males and 44(58.66) females with overall mean age 26.30±9.45 years. There were 41(35.35%) non-survivors; 11(26.82%) males and 30(73.18) females with overall mean age 28.21±11.16 years.During hospitalisation, the non-survivors showed drastically decreased levels of all arterial blood gas paramters with severe clinical outcomes ( p <0.05). As the number of aluminum phosphide pills increased, the chance of survival decreased ( p <0.05). The non-survivors spent an average of 32.51±16.02 hours in hospital (range: 6-59 hours). Conclusion: Patients who ingested more aluminum phosphide pills had more abnormal arterial blood gas parameter with severe clinical outcomes. Also, they had lower chance of survival and unfavourable response to treatment.


Introduction
Aluminum phosphide (AIP), commonly known as the 'wheat pill' , is a fumigant used in agriculture and household settings for pest control.AIP, a common and inexpensive insecticide, is highly poisonous and a significant cause of severe poisoning in developing countries.In Asia, where it is widely available, people use it as a method of suicide, making it a significant public health concern.Unfortunately, there is no known treatment or antidote for individuals who have been thus poisoned. 1,2s ingestion, inhalation, or contact with the body can lead to serious health hazards.When exposed to moisture, AIP releases a highly toxic gas called phosphine, which interferes with mitochondrial protein synthesis and enzyme function in the heart and the lungs.This can result in heart failure, circulatory collapse, pulmonary oedema and hepatic necrosis.The toxicity of AIP depends on the quantity and quality of the tablets, with fresher tablets having a more significant impact. 3ch wheat pill tablet contains 56.4% AIP and 44.6% ammonium carbonate and weighs 3g.The lethal dose for a person weighing 70kg is between 150mg and 500mg. 2,4pon contact with moisture in the stomach, each tablet can release 1g phosphine gas with the help of hydrochloric acid. 2 The phosphine released in the stomach is absorbed extensively, causing unknown mechanisms of organ damage, and unaltered phosphorus is expelled through the lungs.Phosphine blocks electron transport in cytochrome oxidase non-competitively, leading to cellular hypoxia. 5ile inhalation was previously the primary cause of AIP poisoning, cases of ingestion have increased in recent years, usually as attempted suicide.AIP poisoning poses a severe challenge to doctors in Pakistan and other Asian countries, where the toxicity of the wheat pill is increasingly known.The current study was planned to analyse the effects of AIP poisoning dosage on arterial blood gas (ABG) and clinical outcomes.

Materials and Methods
The cross-sectional study was conducted at the intensive care unit (ICU) of Mardan Medical Complex (MMC), Mardan, Pakistan, from January 2021 to May 2022.After approval from the institutional ethics review boards of MMC and Bacha Khan Medical College, Pakistan, the sampe was raised using convenience sampling technique.Those

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J Pak Med Assoc S. Ali, I. Ahmad, Ashraf, et al.
included were patients of either gender who had attempted suicide by ingesting AIP and tested positive for silver nitrate.Those who those who tested negative for silver nitrate those with missing arterial blood parameters were excluded.
Data was collected after taking informed consent from the participants who were free to opt out of the study at any point.
Arterial blood samples from the patients were collected, and their diagnoses were based on available history at the time of admission to the emergency department, including investigating the caretaker to determine the type of poisoning or the container in which the AIP tablets were found.The number of pills ingested by each patient was estimated by confirming with the patients at the time of admission, with each tablet containing 3g of dosage, including 56.4% AlP and 44.6% ammonium carbonate.1).
AIP dosage and ABG parameters were inversely proportional, and as the dosage increased, the ABG parameters decreased (Table 2).The mean survival ratio for patients who ingested <3 pills was 75(66.6%).Patients who took >3 tablets, or <9g of wheat pills showed substantial differences in all clinical characteristics, and the interventions during hospitalisation were also significantly different between the groups, while clinical and chemical outcomes improved for all survivors who were discharged after receiving intensive care for 7-10 days and appeared to be doing well on follow-up examination a week later (Table 3).
The group ingesting 8 AIP tablets, or 24g, had the lowest ABG parameters, with all non-survivors showing drastically decreased ABG levels at admission and during hospitalisation, while survivors responded favourably to the treatment (Table 4).
Higher AIP dosage meant worse clinical outcomes, while specific indications were also associated with poor outcomes among non-survivor patients (Table 5).
The non-survivors had a mean hospitalisation stay of Data is presented as frequency and percentage or as mean and standard deviation; GSC: Glasgow Coma Scale, SVT: Supraventricular tachycardia, VT: Ventricular tachycardia, , GI: Gasrointestinal; p-value <0.05 is statistically significant while p value with ** Represent the variables' effect is either present in 100% of the population or in 0% of the population, no difference was calculated between groups.
Increasing doses of AIP resulted in changes in ABG parameters, while the clinical outcomes could refer to the overall impact of AIP toxicity on the patient, such as mortality or the need for intensive care (Figure 2).

Discussion
To the best of our knowledge, the current study is the first study to examine how different doses of AIP, a poisonous substance commonly used as a wheat preservative, affect ABG levels and clinical outcomes.In the existing literature, there is a lack of data on the effects of AIP poisoning on ABGs and clinical outcomes.Rehab et al. concluded that power of hydrogen (pH) <7.27 and bicarbonate (HCO3) <13.3 were the best cut-off points for predicting mortality in poisoned patients. 6Shadnia et al. discovered a statistically significant difference in blood pH and HCO3 between people who died from acute AlP poisoning and those who survived. 7The current results were comparable.
Chugh SN et al. reported cases of acute respiratory distress syndrome (ARDS) in patients who had ingested doses ranging from 2 tablets (6g) to 3 tablets (9g) of AIP. 8 Nonsurvivors of AIP poisoning had more severe clinical and chemical manifestations of respiratory distress, such as higher respiratory rates, shortness of breath, and lower ABG parameters, as per the current findings.A dose-dependent

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Open Access J Pak Med Assoc  decrease in ABG parameters was also observed with increasing doses of AIP poisoning, ranging from 1 to 8 tablests, or 3 to 24g.

A)
A study reported high mortality rate of 55-90%, 9 while another study reported it to be 33%. 10In the current study, the mortality rate was 35.3%.The effects of wheat pill poisoning (aluminum phosphide) dosage on arterial blood …… pneumonia, due to a lack of airway refluxes. 12Because the GCS is a scoring system that has been shown to assess brain functions and predict the outcomes of nervous system integrity, 13 physicians should consider the levels of consciousness of poisoned patients and carefully document their medical history.
Mehrpour et al. discovered that patients poisoned with AIP had significantly higher mean blood glucose levels than those with lower levels. 3This suggests that measuring blood glucose levels could aid in risk assessment and treating AIP poisoning.Management of hyperglycaemia may be beneficial by increasing glucose entry into cells and decreasing oxygen consumption.The current study found that hypoxaemia and hyperglycaemia levels were significantly higher in non-survivor patients than in survivors and related to the AIP dosage.
Multiple studies have reported that hypotension occurs in 76% to 100% of cases of AIP poisoning. 8Certain factors, such as blood pressure and heart rate, were significantly different between people who died from AlP poisoning and those who survived after ingestion of AlP tablets in a study 14 and the current findings were consistent with literature.
The time of death in the current study was associated with the AIP dosage, with most deaths occurring between 8 and 59 hours after hospitalisation which was consistant with a previous study. 14e current study has some limitations, as it was carried out at a single centre, and the time between AIP ingestion and hospitalisation was not measured.

Conclusion
The effect of AIP dosage was found to be inversely proportional to ABG parameters.Because there is no specific antidote or treatment for AIP poisoning, supportive care is essential for slowing the progression of the illness to improve the patient's chances of survival.For hospitalised patients with AIP poisoning, monitoring of ABG parameters and their clinical outcomes is critical, particularly for those who ingest >3 AIP pills.
Open Access J Pak Med Assoc

Figure- 2 :
Figure-2: Summary diagram (left) showing the relationship between aluminum phosphide dosage and arterial blood gas (ABG) parameters, and the relationship (right) between aluminum phosphide dosage and clinical outcomes.

Table - 1
: Demographic characteristics of survivors and non-survivors.
Data is presented as frequency and percentage or as mean and standard deviation; p-value <0.05 is statistically significant.

Table - 3
: Wheat pill poisoning dosage among survivors and their clinical outcomes.

Table - 4
: Wheat pill poisoning dosage among non-survivors and their arterial blood gas (ABG) parameters.Data is presented as frequency and percentage or as mean and standard deviation; (PO2: Partial pressure of oxygen, PCO2:Partial pressure of carbon dioxide, HCO3: Bicarbonate, O2: Oxygen content: Ph: Power of hydrogen; p-value <0.05 is statistically significant.

Table - 5
:Wheat pill poisoning dosage among non-survivors and their clinical outcomes.Data is presented as frequency and percentage or as mean and standard deviation; GSC: Glasgow Coma Scale, SVT: Supraventricular tachycardia, VT: Ventricular tachycardia, SOB: Shortness of breath, GI: Gasrointestinal; p-value <0.05 is statistically significant while p value with ** Represent the variables' effect is either present in 100% of the population or in 0% of the population, no difference was calculated between groups.