Poisoning is a critical medical emergency that demands prompt evaluation, systematic management, and rapid stabilization of the patient. The primary goal is to prevent further absorption of the toxin, support vital functions, and initiate specific antidotal therapy when required. The general principles involved in the management of poisoning form the foundation of clinical toxicology and guide healthcare professionals in handling diverse toxic exposures effectively.
1. Stabilization
The first and most vital step in managing poisoning is stabilization. Clinicians follow the ABCD approach—Airway, Breathing, Circulation, and CNS Depression. Securing the airway is essential, especially when the patient presents with altered sensorium, risk of aspiration, or inadequate airway protection. Techniques such as the chin-lift, jaw-thrust, removal of secretions, and endotracheal intubation may be required.
Breathing assessment includes evaluation of respiratory rate, rhythm, and oxygen saturation. Certain toxins such as opioids, sedatives, and organophosphates impair respiratory drive. Oxygen therapy or assisted ventilation becomes crucial when hypoxia or respiratory insufficiency is present.
Circulatory stabilization involves monitoring pulse, blood pressure, and perfusion. Hypotension may occur due to cardiotoxic substances, arrhythmias, or shock. Fluid boluses, vasopressors, and ECG monitoring are often needed to restore haemodynamic stability.
Central nervous system depression is a common manifestation of poisoning. Assessment using the Glasgow Coma Scale helps determine severity and need for airway support. Early identification of coma or seizures is vital to prevent complications such as aspiration and hypoxic injury.
2. Evaluation
Once the patient is stabilized, clinical evaluation begins. This includes history taking, physical examination, and necessary laboratory investigations. Sources of history may include the patient, relatives, container labels, or first responders. Details regarding substance type, quantity, route, and time of exposure guide the treatment decisions.
A focused physical examination helps identify toxidromes—clinical patterns that suggest specific poison classes. Diagnostic investigations may include blood gases, serum electrolytes, ECG, toxicology screening, and organ function tests.
3. Decontamination
Gastrointestinal decontamination aims to reduce further toxin absorption. Common methods include activated charcoal, gastric lavage, and, rarely, induced emesis. Activated charcoal is the most widely used method due to its ability to bind a large variety of toxins and prevent their systemic absorption. Gastric lavage is reserved for life-threatening ingestions when the patient presents within one to two hours of exposure.
Dermal and ocular decontamination may also be required in cases of chemical or industrial toxin exposure. Immediate removal of contaminated clothing and irrigation with copious water significantly reduces systemic absorption and local tissue injury.
4. Poison Elimination
Enhancing toxin elimination is another important step in management. Certain toxins are eliminated through the kidneys, and manipulating urine pH can accelerate excretion. Forced alkaline diuresis is particularly useful for substances like salicylates and phenobarbitone. Extracorporeal techniques such as haemodialysis, haemoperfusion, and haemofiltration may be indicated in cases of severe poisoning with dialyzable toxins like methanol, ethylene glycol, lithium, or certain heavy metals.
5. Antidote Administration
Although supportive care alone is sufficient for most poisonings, specific antidotes play a crucial role in selected cases. Antidotes act through various mechanisms such as receptor competition, detoxification, complex formation, or reversal of physiologic effects. Examples include naloxone for opioid poisoning, atropine and pralidoxime for organophosphate toxicity, N-acetylcysteine for paracetamol overdose, and hydroxocobalamin for cyanide poisoning. Timely antidote administration can be life-saving and may significantly improve patient outcomes.
6. Nursing and Psychiatric Care
Nursing care focuses on continuous monitoring, prevention of complications, and maintenance of hygiene and nutrition. Since many poisoning cases involve intentional self-harm, psychiatric evaluation is an essential component of long-term management. Addressing underlying mental health issues is crucial to prevent recurrence.
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PATH: PHARMD/ PHARMD NOTES/ PHARMD FOURTH YEAR NOTES/ CLINICAL TOXICOLOGY/ GENERAL PRINCIPLES INVOLVED IN THE MANAGEMENT OF POISONING.