Phenobarbitone Poisoning
Ms. Nalini is admitted in the emergency unit. According to her parents, she consumed phenobartione tablets as she failed in her examinations. Answer the following :
List the goals of emergency treatment. (2)
Discuss the general management for ingested poisons. (10)
What counselling will you give Miss.Nalini and her parents (3)
Goals of emergency treatment
Take a detailed history of the medicines taken to find out what other drugs are present in combination with phenobarbitone
Be ready to deal with hypoxia, acute respiratory distress syndrome (ARDS),
Treat hypotension
CNS depression gradually improves over 2 days for short-acting barbiturates and over 4-7 days for long-acting agents and hence supportive treatment has to be sustained for at least one week.
Guard against hypothermia
Procedures
Endotracheal intubation : to protect the airway and to ventilate and oxygenate the patient.
Lumbar puncture : to rule out meningitis.
Orogastric intubation and lavage : for massive oral overdose with ileus.
Pulmonary artery catheter insertion : to determine the cause of shock.
Hemodialysis or hemoperfusion : for long-acting barbiturate overdose with pulmonary edema, renal failure, and cardiovascular instability.
Once the patient is stabilized, drug removal is performed. Removal may be accomplished with several different methods such as orogastric lavage, activated charcoal, forced alkaline diuresis, dialysis, and, possibly, exchange transfusion.
General Management of Ingested Poisons
Many poisons need only supportive treatment :-
Airway protection
Cardiovascular support
Immediate identification and treatment of correctable metabolic and structural abnormalities
Once the patient is stabilized:-
Gut decontamination
And elimination enhancement are performed.
Airway support
CNS depression may lead to loss of airway protective reflexes : risk of aspiration pneumonitis. Assessment and stabilization of the airway must be performed early in the course of poisoning
Mechanical ventilation with oxygenation must be provided immediately.
Positive pressure ventilation should be used with caution.
Cardiovascular support
Hypotension, which is due to vasodilation and direct myocardial depressant effects, responds to crystalloid bolus infusions and rarely requires vasopressors.
Insertion of a pulmonary artery catheter and hemodynamic measurements may guide fluid and vasopressor therapy.
Metabolic support:
The infusion of 25-50 g of dextrose. Electrolyte balance.
Decontamination and elimination
orogastric lavage
Activated charcoal
Forced diuresis
Dialysis
Exchange transfusion.
Extracorporeal drug removal
Conventional hemodialysis, hemoperfusion, or both
Other measures:
Plasma exchange transfusion continuously.
Hypothermia may be treated with passive rewarming and continuous temperature monitoring. Rarely, patients may require active rewarming maneuvers.
