Clinical features:

• Acute cholinergic syndrome: occur usually within one hour and lasts 48-72 hours

 

Muscarinic effects: DUMBELS D- Diaphoresis, diarrhea U- Urination M-Miosis B- Bradycardia; bronchospasm; bronchorrhea E- Emesis L- Lacrimation S- Salivation	Nicotinic effects: Muscle fasciculation Cramping Weakness Diaphragmatic failure Autonomic- HTN, tachycardia, mydriasis (Opposite to muscarinic features)
CNS effects: Anxiety Emotional lability Restlessness Confusion Ataxia, Tremors, Seizures, Coma

 

• Breath, vomit or clothes- pungent garlic-like odor (sulphurated OPCs)
• Pathognomonic features– miosis and muscle fasciculation
• Tachycardia may occur in 20% cases
• Parkinsonian features, pancreatitis, transient hepatic dysfunction, vocal cord paralysis, pyrexia
• Arrhythmias and cardiomyopathy 

 

1. Intermediate syndrome 

• Develops 1-4 days after resolution of acute cholinergic syndrome
• Persists for 2-3 weeks
• C/F: Weakness spreads rapidly from ocular muscle to those of head and neck, proximal limb, muscles of respiration.
• Treatment:

• No specific treatment
• Supportive care: airway, ventilation

 

1. Organophosphate induced delayed neuropathy (OPIDN)

• • 2-3 weeks after exposure

• C/F: mixed sensory-motor polyneuropathy

• Muscle cramps
• Numbness, paraesthesia
• Flaccid paralysis of lower then upper limbs

• Lower limb- foot drop, high stepping gait, paraplegia
• Upper limbs-  wrist drop

• DTR- lost

• Treatment: 

• No specific therapy
• Physiotherapy

• Recovery –

• often incomplete, may be limited to hand and feet, although substantial functional recovery may occur after 1-2 years.

 

Lab studies:

1. RBC and plasma cholinesterase activity :  < 10% severe poisoning
2. CXR: pulmonary edema
3. ECG: long QT interval, elevated ST segments, inverted T waves→ arrhythmia, IHD
4. Others: Oxygen saturation, ABG, urea, electrolytes, amylase, glucose

 

Treatment:

Managed in HDU/ICU

• External decontamination: 

• removal of clothes  
• Eye irrigation with normal saline or water 
• Skin washing with soap and water

 

• Gastrointestinal decontamination: 

• Gastric lavage, activated charcoal

 

• Maintenance of airway: OP suction for excessive secretion
• Maintenance of breathing: High flow O2 therapy
• Maintenance of circulation

• IV access
• IV fluid therapy

 

• Drugs:

1. Atropine: 

Bolus 1.8 -3 mg → double every 3-5 minutes

Look for signs of atropinization/end point of atropine therapy

1. Clear chest on auscultation
2. Heart rate > 80 /min
3. SBP  > 80mm (Hg)
4. Pupil- no longer pinpoint 
5. Dry axillae

 

            Maintenance Dose: 

• 10-20% of total initial dose / hour to maintain those targets by infusion.
• Maintain atropinization for 24-48 hours

[ Tachycardia and mydriasis must not be used to limit or stop subsequent doses of atropine. The end point of atropinization is dried pulmonary secretions and adequate oxygenation.]

            

1. Oxime (Pralidoxime):

• Should be given rapidly after exposure
• 30 mg/kg loading dose
• Maintenance dose: 8-10 mg/kg/hour until clinical recovery or 7 days, whichever is longer.
• Given as IV infusion → rapid administration provokes hypotension.

 

1. IV magnesium sulfate

 

Treatment of complication: 

• Seizure, agitation

• • Airway ventilatory support
  • IV diazepam

• Correction of hypoxia, acidosis, EI

• Ventricular arrhythmia

• Correction of hypoxia, acidosis, EI
• Anit-arrhthmic drugs

• Respiratory failure in ACS

• Ventilatory support
• Atropine, pralidoxime
• Correction of hypoxia, acidosis,  EI

• Respiratory failure in intermediate syndrome

• • Supportive care

• Airway ventilatory support

 

Respiratory failure due to 

1. Central respiratory depression 
2. Secretions                 
3. Bronchoconstriction 
4. Muscle paralysis)

Complications:

• Immediate

• Ventricular arrhythmia, seizure

• Within 24 hours

• Respiratory failure due to acute cholinergic crisis 

• Within 10 days

• Respiratory failure due to respiratory muscle paralysis in intermediate syndrome.

• Late:

• Ventricular arrhythmia including Torsades de pointes 

 

Prognosis:

• Death rate upto 25%
• Respiratory failure is the most common cause of death

 

SAQ. A 20-year-old woman referred to a tertiary care hospital for developing generalized weakness along with difficulty in keeping eyes open and keeping the neck upright. Her skin is dry and pupils are widely dilated. She has been treated in Sadar hospital for self-poisoning of agricultural agents 

 

1. What is the most likely diagnosis?

• From the given scenario most likely diagnosis is- Atropine overdose/toxicity with intermediate syndrome. 

 

1. Mention the clinical information you will try to elicit immediately.

Evaluation:

• H/O OPC poisoning: Amount, Duration, Condition after OPC 
• Dose of atropine: Dose, Frequency
• Duration of symptoms 
• Duration of IMS

 

1. Give immediate management for this patient.

Management:

• Hospitalization in HDU or ICU (If ventilation is required) 
• Maintenance of ABC
• Fluid, electrolyte maintenance
• Reduce dose of atropine
• Correction of any electrolyte imbalance, infection or other factors
• Monitoring for IMS: Maintenance of airway, Ventilation, Physiotherapy