TCA OVERDOSE

Remember the actions of TCAs:

• SNRI
• Anticholinergic: All D's (Dry Mouth, Dry skin and hyperthermia, DIlated pupils, Depressin of Respiration, Disorder Heart Rhythm,  Delayed Gastric Emptying, Distended Bladder) and Agitation (Remember the atropine psychosis in OPC Poisoning)
• Alpha 1 Blocker: Hypotension
• Na+ Channel Blocker: Wide PR, QRS, QT

Fatal Dose: 15 mg/kg

Management:

Approach in ABCDE Method:

Airway: Nasal Oxygen

Breathing: Assisted Ventilation

Circulation: IV Access (Lab workup: Venous blood Gas for Acidosis, FBC, U & Es, Renal Functions, Acetaminophen levels), EKG, Vitals, Monitoring, 

IV Fluids

Antidotes:

If taken within 2 hours: Give Oral Charcoal 50 gms

Correct Acidosis: With NaHCO3

50 ml of 8.4% over 15 minutes, then 500 ml of 1.8% over 4 hours (Give HCO3, even if pH is normal, try to keep pH > 7.5, if QRS > 100, monitor hypokalemia)

IV benzodiazepines for convulsions (Avoid phenytoin -- Na+ Channel blocker)

Treat Arrythmia with fluids and NaHCO3, avoid Antiarrythmic Class 1a and 1c -- Na+ Channel Blockers

HD if required,

Refer TOXBASE

Refer ITU

ACETAMINOPHEN (PARACETAMOL) OVERDOSE

A very common OSCE scenario presented as:

• Obtaining History
• Management
• Psychiatric Assessment
• Assessing Capacity
• Assessing Mental Status

OBTAINING HISTORY:

Hi, My Name is Dr ABC, one of the ED Registrars who will be taking care of you today. May I know you name please? How old are you? And what do you do for your living?

Are you having any discomfort or pain? I want to assure you that I would provide you with every assistance, including pain killers to make you more comfortable.

If attendant is present, ask her name and relationship?

Ask the patient if she wants him/her to be present or can they wait outside in the Lobby?

If unstable, begin resuscitation.

I would like to ask you what brought you here today?

 Current Symptoms:

 Do you have any pain in abdomen? Vomiting? 

Event:

What have you taken? Do you have any packets or labels? Exactly when did you take it? How many tablets? Did you take anything else along with it,.... like any other medications or drugs, or alcohol?

Psychiatry:

Why did you take the overdose? Did you want to kill yourself or was it a cry for help?

Did you plan about doing it? Like trying not to be found? Closure of bank accounts? Suicide note?

How do you feel now?

Did you come here by yourself or under duress?

Did you try hurting yourself before too?

Assess risk of severe depression by asking about Sleep, Loss of interest, Guilt feeling, memory and concentration, appetite, psychomotor symptoms.

Assess Suicidal risk by asking SAD PERSONS Score: (Male 1945, single without social support and feeling hopeless and has a plan)

Social History:

Smoking, drugs, alcohol, Social support, Schooling, Stress at work or home

Medical illness:

Do you have any other medical illnesses? like liver disease, kidney disease or infections

Do you take any medications routinely? 

Are you allergic to any medications?

Have you been diagnosed of any psychiatric illnesses like depressions?

Management:

Bloods for CBC, U & Es, glucose, Coagulations Panel, group and type, LFTs, Serum Acetaminophen level, VBGs, lactate. Urine Toxicology screen

Ask for a nomogram

If less than one hour of intake, 50 gm of Charcoal PO

IV NAC

Hospitalize

Psychiatric referral

If denies NAC/treatment:

• Assess Capacity : Understand what is proposed, retain, weigh the benefits and risks involved, make a decision and communicate it
• If capacitated and no risk of repetition discharge (0 - 4 SAD PERSONS)
• If Capacitated, but risk of repetition of self harm (4+ SAD PERSONS), use section under Mental Capacity Act and hold.
• Explore Needle phobia
• Offer Oral Methionine

Cocaine Toxicity

Cocaine Toxicity

Remember Cocaine is a sympathomimetic, hence would cause Agitation, Tachycardia, Hypetension, Hyperthermia, and myocardial ischemia

Cocaine induced Myocardial Ischemia/Chest Pain:

IV Benzodiazepines (diazepam/lorazepam): Controls agitation, hypertension, seizures, and chest pain

IV nitrates (1^st line to manage angina/hypertension), Ca+2 Blockers as second line agents

(Do not use beta blockers as it may cause paradoxical hypertension, and vasoconstriction due to unopposed alpha effects, Phentolamine could be used but it may cause a drastic fall in BP and should be avoided in patients with history of myocardial ischemia)

Aspirin PO

If chest pain still persists, and EKG shows myocardial injury: reperfusion therapy (rTPAs or PCI)

Toxins & Antidotes

Agent	Indication
Activated charcoal with sorbital	used for many oral toxins
Adenosine	Theophylline antidote for adenosine poisoning
Atropine	organophosphate and carbamate insecticides, nerve agents, some mushrooms
Beta blocker	theophylline
Calcium chloride	calcium channel blockers, black widow spider bites
Calcium gluconate	hydrofluoric acid
Chelators such as EDTA, dimercaprol (BAL), penicillamine, and 2,3-dimercaptosuccinic acid (DMSA, succimer)	heavy metal poisoning
Cyanide antidote (amyl nitrite, sodium nitrite, or thiosulfate)	cyanide poisoning
Cyproheptadine	serotonin syndrome
Deferoxamine mesylate	Iron poisoning
Digoxin Immune Fab antibody (Digibind and Digifab)	digoxin poisoning
Diphenhydramine hydrochloride and benztropine mesylate	Extrapyramidal reactions associated with antipsychotic
Ethanol or fomepizole	ethylene glycol poisoning and methanol poisoning
Flumazenil	benzodiazepine poisoning
Glucagon	beta blocker poisoning and calcium channel blocker poisoning
100% oxygen or hyperbaric oxygen therapy (HBOT)	carbon monoxide poisoning and cyanide poisoning
Insulin- with Glucagon	beta blocker poisoning and calcium channel blocker poisoning
Leucovorin	methotrexate and trimethoprim
Methylene blue	treatment of conditions that cause methemoglobinemia
Naloxone hydrochloride	opioid poisoning
N-acetylcysteine	Paracetamol (acetaminophen) poisoning
Octreotide	oral hypoglycemic agents
Pralidoxime chloride (2-PAM)	organophosphate insecticides, followed after atropine
Protamine sulfate	Heparin poisoning
Prussian blue	Thallium poisoning
Physostigmine sulfate	anticholinergic poisoning
Pyridoxine	Isoniazid poisoning, ethylene glycol
Phytomenadione (vitamin K) and fresh frozen plasma	Warfarin poisoning and indanedione
Sodium bicarbonate	ASA, TCAs with a wide QRS

ALS Pearls for MCEM B Part 2

Use of Sodabicarbonate in Cardiac Arrest

Indications: Alkalinization to correct pH if cardio-respiratory arrest due to HYPERKALEMIA (K+ more than 5.5), TCA overdose, or prolonged arrest state

Dose: 50 ml of 8.4% solution (50 mmol)

It is not recommended to use it routinely:

1.  Exacerbates intracellular acidosis:

            a) Generates CO2 which diffuses rapidly into cells (respiratory acidosis)

b) Stimulates phosphofructokinase in glysolysis to generate more pyruvate, thereby increased lactate formation (lactic acidosis)

2. Shifts O2-Hb curve to left, thereby causing decreased release of O2

3. Negative ionotropic effect on ischemic myocardium

4. Large osmotically active Na load, causing cellular swelling