Celphos ( Aluminium phosphide ) poisoning in Emergency Room.

             Celphos poisoning

Aluminum phosphide (AlP) is used to preserve grains all over the world. It is also known as celphos and is one of the most dreaded poisons one can ever encounter in toxicology. The salt is usually available in tablet and pellet forms. AlP poisoning is common in all parts of the world but is found more commonly in developing countries like India and is often implicated in accidental and suicidal poisonings in India. The fatal dose is around 0.5 g and acute poisoning with these compounds may be directly due to ingestion of the salts or indirect from the accidental inhalation of phosphine generated during their approved use. Many lives have been lost in the last three decades, especially among the young rural population of northern India. It is not just limited to the agricultural society, but the incidence is increasing in urban families also. Previously, the laws and legislations were not that strict and it was easily available on the counter; but in the last few years, stricter norms have reduced its easy availability, even though they are still not enough to reduce the suicidal rate due to its consumption, which traumatizes so many families. It is a highly toxic compound that releases phosphine gas on contact with moist surfaces and patients can present clinically with gastrointestinal (GI) hemorrhage, arrhythmias, shock, renal and hepatic failure, central nervous system disturbances and ultimately leading to death in almost 100% of cases. Most patients who survived had either taken a very small amount or the tablet had been exposed to air, thus rendering it non-toxic. Patients remain mentally clear till cerebral anoxia due to shock supervenes resulting in drowsiness, delirium, and coma. Several ECG changes ranging from ST-segment elevation/depression, PR and QRS interval prolongation, complete heart blocks to ectopics and fibrillation have been observed. Reversible myocardial injury has also been reported.

The breath of patients who have ingested AlP has a characteristic garlic-like odor. Confirmation of diagnosis is based on the patient's history and a positive result (blackening) on tests of the patient's breath with paper moistened with fresh silver nitrate solution or by chemical analysis of blood or gastric acid for phosphine.

Celphos poisoning has always been a big headache and menace for the intensivists throughout the world probably due to nonavailability of its antidote and 100% mortality which does not encourage the physicians to try wholeheartedly to salvage the patients. The literature is full of different drugs and trials to counter its irreversible toxic effects, but hardly with any concrete success. Keeping all these facts and figures into consideration, we undertook a retrospective analysis at the Intensive Care Unit (ICU) of our institute, whereby we tried to treat the patients with a mixture of coconut oil and sodium bicarbonate used for gastric lavage, mixed in equal proportions, to make lavage solution of 100 ml. The main aim was to find whether the regimen we devised is of any help in saving the precious lives of the people who in a rage and fury consume this deadly poison, the antidote for which is still not in the sight. The objective was to see the effectiveness of this medication combo to decrease the very high the mortality and morbidity as a result of the consumption of this poison.

Emergency department and ICU management:

A patient arrives in the ER, the patients  made comfortable on the bed, monitoring gadgets were attached for Heart Rate (HR), Non-Invasive Blood Pressure (NIBP), ECG, Pulse Oximetry (SpO₂) and End-tidal carbon dioxide (EtCO₂) and Ryle's tube is inserted through nasal route. The patients who were grossly unstable hemodynamically or had respiratory distress were induced with injection ketamine 2-mg/kg-body weight and injection vecuronium bromide 0.1-mg/kg body weight. 
Endotracheal intubation with appropriate size cuffed endotracheal tube and patients put on mechanical ventilation. 
Gastric lavage initiated with aliquots of 50 ml of coconut oil and 50 ml of sodium bicarbonate solution and continued for the next half an hour, with simultaneous aspiration being after every 2–3 minutes through Ryle's tube. Coconut oil was just heated to lukewarm temperature so as to make a miscible solution with sodium bicarbonate. 
The procedure of gastric lavage is usually done 12–15 times in the first hour. Initial 30 ml lavage was sent to the forensic laboratory for toxicological analysis.

Intravenous access through the internal jugular vein is establish for central venous pressure monitoring as well as for guiding the fluid therapy in the majority of patients who had presented with cardiovascular instability, respiratory distress, and renal failure. 
In a few patients who have severe cardiogenic shock, an arterial line is also secure through radial/dorsalis pedis artery for observing the beat-to-beat variation of HR and BP. 
Symptomatic treatment is initiated on a patient to patient basis. Magnesium sulfate, dopamine, dobutamine, amiodarone infusions, and other appropriate intravenous drugs is given depending on the patient's clinical presentation and symptomatology, as well as arrhythmias and blood pressure variations. Urine output is monitoring through Foley's catheter attached to urobag. Patients who required mechanical ventilation is kept sedate with injection midazolam and paralyzed with injection vecuronium. During this period, strict and vigil monitoring of all vital parameters and treatment regimens were titrated according to the clinical condition of the patients. 
Gastric lavage was again perform after 1 hour of admission with the same solution for the next half an hour.

After admission in the ICU, all the baseline routine and specific investigations including regular arterial blood gas analysis (ABG). Soda bicarbonate is  give empirically to all patients in a dose of 1–1.5 mEq/kg body weight and further adjusted for correction of metabolic acidosis as per ABG reports.

The main principles of treatment are the following.

1.                Carry out methods to absorb phosphine through GI tract and neutralizing the HCl with soda bicarbonate and coconut oil, as explain earlier.

2.                Reduce organ toxicity with appropriate interventions.

3.                Enhance phosphine excretion, especially through lungs, by increasing the respiratory rate, which becomes easier when the patient is paralyzed, sedated and put on mechanical ventilation. This results in decreasing the basal metabolic rate of the body and decreased oxygen requirement, thus compensating the actions of inhibited cytochrome oxidase to some extent.

4.                Phosphine is excreted through urine also. Therefore, adequate hydration and renal perfusion by low-dose dopamine 4–6 μg/kg/minute must be maintained. Diuretics are not useful in the presence of profound shock.

Suggestions:

Certain specific measures can be adopted to reduce the fatal episodes of AlP. 

These include the following.

1.                Role of hyperbaric oxygen can be studied especially in the background of inhibition of the mitochondrial respiratory chain.

2.                The gastroscopy can be used to remove the dissolved pellet.

3.                Water should not be used as a lavage agent.

4.                Some highly the pungent and nauseating substance may be added to the pellets.

5.                Strict laws and legislations can be made regarding the free sales of the chemical.

6.                Availability of single tablet pack encased in hard plastic material with hard spikes will be helpful.

7.                Social awareness regarding the handling of the substance and its lethal consequences is required.

8.                Alternatives to celphos, which are less toxic and fatal, should be manufactured to serve the same purpose.

9.                Lab research should be undertaken extensively to find out its antidote.