Is there a statistically significant difference in the occurrence of symptomatic bradyarrhythmia including first-degree, second-degree, and third-degree atrioventricular blocks between patients who received oral magnesium sulfate along with activated charcoal within 24 hours of acute oleander poisoning compared to standard therapy?

Study Settings - Teaching Hospital Batticaloa and Teaching Hospital Kurunegala

Randomization: Patients presenting with acute oleander poisoning within 6 hours of ingestion, who meet the inclusion/exclusion criteria and provide informed written consent, will be randomly assigned to one of two groups: the magnesium sulfate intervention group (Group A) or the control group (Group B). Stratified block randomization will be used to ensure homogeneity between the intervention and control groups.

Informed consent will be obtained from the patient or from the guardians where necessary. Their incident history, past medical history and relevant details will be collected using an interviewer administered questionnaire.

Intervention: Once the randomization is done and patients will be assigned to intervention or control group by the doctor who assign patients. Patients will be given index numbers in the form of THB_001 onwards according to the recruitment order. Study will be carried out as double-blind randomized control trial in which both patient and investigator will not know about randomization.

Intervention Group Patients in the intervention group will receive activated charcoal at a dose of 1 g/kg (up to a maximum of 50 g) mixed in 200 ml of distilled water at the time of recruitment. This will be followed by 25 g of activated charcoal in 100 ml of distilled water every 2 hours for the first 24 hours. Additionally, 4 g of magnesium sulphate will be administered at recruitment and every 6 hours, alongside the multiple doses of activated charcoal, for the first 24 hours. The route of administration will be oral.

Control Group Patients in the control group will receive activated charcoal at a dose of 1 g/kg (up to a maximum of 50 g) mixed in 200 ml of distilled water at the time of recruitment. This will be followed by 25 g of activated charcoal in 100 ml of distilled water every 2 hours for the first 24 hours. Additionally, 25 ml of dis-tilled water will be administered at recruitment and every 6 hours, alongside the multiple doses of activated charcoal, for the first 24 hours. The route of administration will be oral.

For the control group, all standard treatments, except magnesium sulphate, will be administered according to the treatment protocol. Instead of magnesium sulphate, a placebo (distilled water) will be provided along with activated charcoal as outlined in the protocol.

Following procedures will be done in addition to the above mentioned interventions.

• Connect to a cardiac monitor on admission and measure blood pressure, pulse rate and respiration on admission and every 2 hourly for 1st 24 hour
• Collect 5 ml blood for serum potassium on recruitment and repeat after 6 hours and 12 hours of recruitment
• Collect 5 ml blood for serum magnesium on recruitment and repeat after 2 hours of oral magnesium sulphate administration
• Start on Normal saline (crystalloid) 100 ml / hour on recruitment and continue for 24 hours
• If severe bradycardia (< 60 bpm) or second-degree heart block is present, give atropine 3mg – 6 mg IV and plan for temporary cardiac pacing
• If hyperkalemia is present
a) Serum potassium 5 – 5.5 mmol/L 10% Dextrose in a rate of 80 ml/hour
b) Serum potassium 5.5 – 6 mmol/L 5 U soluble insulin with 50 % dextrose 50 ml over 10 minutes in to a large vein Nebulize with salbutamol (avoid if tachycardia is present)
c) Serum potassium > 6 mmol/L 10 U soluble insulin with 50 % dextrose 50 ml Repeat serum potassium hourly. If serum potassium is continuously high start on 3U/hour soluble insulin with 10% dextrose infusion


Discharge criteria - If sinus rhythm with heart rate >60 per min for 24 hours patient can be discharged

1. The patient should be admitted to the study hospital within 6 hours of oleander ingestion
   

2. Patients should have signs and symptoms suggestive of systemic oleander poisoning:
   Presence of any of the following signs within first 2 hours of admiss ion would be considered as evidence of systemic intoxication.
   

3. Bradycardia with a heart rate of less than 60 beats /minute
   

4. Presence of reverse tick sign of digoxin effect in ECG
   

5. Systolic blood pressure less than 80 Hg mm
   
   

6. Symptoms such as nausea, vomiting, abdominal pain, diarrheoa, xanthopsia

1. Patients below 16 years of age
   
2. Pregnant women
   
3. Patients with a history of ischemic or valvular heart disease
   
4. Patient with a history of significant cardiac diseases
   
5. Patients with a history of co-poisoning with other pharmacological agents which affect heart rate, such as calcium-channel blockers, beta-blockers, amiodarone and other antiarrhythmic drugs
   
6. Patients who were on medication which affect heart rate and rhythm, such as calcium-channel blockers, beta-blockers, amiodarone and other antiarrhythmic drugs.
   
7. Patients who were already given oral magnesium sulphate following acute oleander poisoning