History: A 27 yr old female brought to ED with A/H/O ingestion of 50ml of Dichlorvos solution at her home 35 minutes ago. On arrival primary survey was
A – Airway compromised
B – Breathing Laboured, Spo2 – 37% on RA, B/L crepts +nt
C – BP – 166/78 mmhg P – 90 bpm
D – E1V2M2 Pupils – B/L constricted, RBS – 112 mg/dl
ABG done shows ph 6.98 pco2 23 pO2 68 hco3 13 Lac 17 AG 22. What’s the diagnosis and how will you manage this patient?
Answer: Dichlorvos is an organophosphate compound.
Look for signs & symptoms of OP poisoning & ask the attendants to bring the sample :
- Muscarinic manifestations : DUMBELS – Diarrhoea; Urinary incontinence; Miosis; Bradycardia, Bronchorrhea and Bronchospasm; Emesis; Lacrimation, Low blood pressure; Salivation and Sweating. Others include abdominal cramps, hypertension, fasciculations, muscle weakness, confusion, coma, seizures.
- Nicotinic manifestations: Twitching, fasciculations, weakness, diminished respiratory effort, HTN & tachycardia.
- CNS manifestations: Anxiety, restlessness, tremors, convulsions, confusion, weakness and coma.
Diagnosis:
- Clinical diagnosis is based on the toxidrome
- History of exposure
- ABG, ECG (Prolong QT), CBC, LFT, KFT
- Cholinesterase assay if available
Rx plan:
- Evaluate ABCD.
- Stable patient: Decontamination (Healthcare workers should wear PPE).
- Unstable patient: Resuscitation first followed by decontamination. (Never use succinylcholine for intubation).
- Gastric lavage within first 1hr of ingestion (Seal GL sample for MLC) with NS & activated charcoal is given orally at a dose of 1-2 g/kg body weight.
- Inj. Atropine 1mg or 0.01 to 0.04 mg/kg IV. Double the dose every time and target end points is atropinisation (Clear chest on auscultation with no wheeze, HR>80, pupils no longer pinpoint, dry axilla & SBP >90 mmHg). Once atropinised set up an infusion of atropine at an hourly dose of 10-20% of the total dose of atropine given initially.
- Inj. Pralidoxime (2-PAM) is a cholinesterase reactivator. It is effective for nicotinic as well as muscarinic features of toxicity. 30 mg/kg initially over 20 mins followed by a constant infusion at 9 mg/kg/ hour. It is usually continued for 12-24 hrs.
Complications:
- Intermediate Syndrome – Syndrome of muscular paralysis occurs within 24-96 hours after ingestion of an organophosphate and following treatment of acute cholinergic syndrome. Muscle weakness affects predominantly neck flexors, proximal limb muscles, those supplied by cranial nerves & respiratory muscles.
- Organophosphate-lnduced Delayed Polyneuropathy (OPIDN) – Cramping muscle pain in the lower limbs, distal numbness and paraesthesia followed by progressive weakness, depression of deep tendon reflexes in the lower limbs > the upper limbs.
Ddx :
- Carbamate toxicity
- Nicotine toxicity
- Methacholine toxicity
- Arecoline toxicity
- Bethanechol toxicity
- Pilocarpine toxicity
- Pyridostigmine toxicity
- Neostigmine toxicity
- Mushroom poisoning
- Poison hemlock