Acute Medicine Flashcards
3,4–Methylenedioxymethamphetamine (Ecstasy) MDMA
-This causes anxiety, restlessness, hyperthermia, ataxia, blurred vision, confusion and syncope.
- It can cause palpitations and chest pain.
- Tachycardia, hypertension
- GI symptoms include dry mouth, nausea, abdo pain.
- It also causes pupillary dilatation
Diamorphine (Heroin)
- Mild hypotension and mild bradycardia are commonly observed with heroin use.
- ->These are attributable to peripheral vasodilation, reduced peripheral resistance and histamine release, and inhibition of baroreceptor reflexes.
- Respiratory depression, due to heroin’s effect on the brain’s respiratory centres is a hallmark.
- -> However, the presence of tachypnoea should prompt the search for complications of heroin use such as pneumonia, pulmonary oedema, pneumothorax; or an alternative diagnosis such as shock, acidosis or CNS injury.
Gamma Hydroxybutyrate (Grievous Bodily Harm, GHB).
- It has a myriad of neurological effects.
- After GHB ingestion, the patient may have a period of euphoria that is rapidly followed by a period of profoundly depressed level of consciousness (hence its reputation as a date rape drug).
- This may progress to coma with a Glasgow Coma Scale of 3.
- GHB intoxication characteristically produces episodes of agitated delirium that can precede or follow the period of stupor or coma.
- Seizure like movements and myoclonus are common. - More commonly would cause bradycardia and hypotension.
Ketamine (special K)
- Ketamine is a rapid acting general anaesthetic producing an anaesthetic state
- Characterised by profound analgesia, normal pharyngeal/ laryngeal reflexes, normal or slightly enhanced skeletal muscle tone, cardiovascular and respiratory stimulation, and occasionally a transient and minimal respiratory depression.
- It does cause pupillary dilatation
Neuroleptic malignant syndrome
See syndromes
Serotonin syndrome
See syndromes
Naloxone
Used for opiate OD
Sodium bicarbonate
Used in TCA overdose
- Plasma alkalinization and TCA plasma protein binding
- Intracellular alkalosis and TCA receptor binding
- Intracellular hypopolarization
- Sodium load
- Correction of metabolic acidosis
- Volume loading
- Other pharmacokinetic effects
Digoxin OD
- Digoxin inhibits sodium ATPase
- Bradycardia
- Hyperkalemia (early)
- Confusion
- Arrythymia
ECG changes show evidence of AV dissociation with 1st-3rd degree heart block
TCA overdose
Rapid onset 1-2 hours
- tachycardia
- Hypotensiom
- Sedation and comas
- Seizures
- -> if QRS >100ms
QT prolongation –> broad complex dysarrythmia
–> if QRS >160ms predictive of VT
- cardiotoxic effects by:
1. block myocardial Na+ fast channels - -> QRS prolongation, tall R wave in aVR
2. inhibit K+ channels - -> QTc prolongation
- -> direct myocardial depression
3. blockade of muscarinic (M1), histamine (H1) and alpha adrenergic receptors
Rx:
IV sodium bicarbonate (Plasma alkalinization and TCA plasma protein binding, Intracellular alkalosis and TCA receptor binding, correction of metabolic acidosis among other things)
Beta blocker/calcium channel blocker overdose
CLINICAL FEATURES:
proportional to the type and amount ingested
CVS: hypotension, bradycardia, AV block, heart failure
RESP: bronchospasm
METABOLIC: hypoglycaemia, hyperkalaemia
NEURO: stupor, coma, seizures
MANAGEMENT
ECG can show:
- sinus bradycardia
- abnormal AV node conduction
- an accelerated junctional rhythm
Rx (antidote):
-Glucagon as first line followed by high dose insulin euglycemic therapy and dextrose –> glucose used as fuel in the heart to increase ionotropy (which CCB OD decreases)
Resuscitation:
- fluid
- beta-agonists
- vasopressors
- atropine
- pacing
Acid-base and Electrolytes Balance:
- hypoglycaemia -> dextrose
- hyperkalaemia: Ca2+ gluconate, dextrose-insulin, -NaHCO3, dialysis, salbutamol
Decontamination:
-activated charcoal if <1 hour and no C
Two beta-blockers require special consideration:
— propanolol -> causes sodium channel blockade -> QRS widening -> treat with NaHCO3
— sotalol -> causes potassium efflux blockade -> long QT -> monitor for Torsades
Hypertensive crisis
RX: Nitroprusside
Colchicine overdose
- Plant based alkaloid
- Rapidly absorbed
- peak serum concentration after 30mins- 3 hours
- 50% protein bound (haemodialysis and haemodilution is not helpful)
- Gastro symptoms within 24 hours (abdo pain, N+V, diarrhoea
- Later features 1-7 days are tachypnoea, low calcium, low po4, hypovolaemia, haematological effects (e.g. leukopaenia, thrombocytopaenia), cardiac dysrhythmias,renal failure and liver damage.
-The cause of death is usually
progressive multiple organ failure and sepsis.
Rx:
- activated charcoal to try and absorb ASAP as no antidote
- High mortality
- -> >0.5mg/kg dose assoc with 10% mortality
- -> >0.8mg/kg dose assoc with 100% mortality
- -> 7mg/kg dose with kill an adult
When activated charcoal not useful or CI
P- Pesticides, petroleum distillates H- Hydrocarbons, heavy metals, > 1 hour post ingestion A- Acids, alkali, alcohols I - Iron L - Lithium S - Solvents
In resus of unknown ingestions
Three S’s
S-seizures –> midazolam. DO NOT give phenytoin as can worsen some ingestions
S-sugar –> treat hypoglycemia
S- shivering –> treat hypothermia
Decontamination
Induced emesis and Gastric lavage is not usually done in kids
Activated charcoal and whole bowel irrigation is very rarely done in kids
-consider if risk assessment predicts severe or life threatening toxicity where supportive care or an antidote is alone not enough to ensure a good outcome
List of meds where “two pills can kill” so needs overnight continuous monitoring
- Sodium channel blockers:
- choloroquine and hydroxycloroquine
- PROPANOLOL
- TCA’s
- atropine
- Calcium channel blockers:
- VERAPAMIL
- DILTIAZEM
- Theophylline SR
- Sulfonylureas (glipizide, glicazide)
- Amphetamine and ecstasy
- Opiates:
- Methadone
- Morphine
- Oxycodone
Drugs where a “mouthful can kill”
- Organophosphates/carbamates
- insecticides
- Hydrocarbons
- kerosene
- eucalyptus oil
- solvents
- Camphor and its oil
- Paraquat = pesticide
- Napthalene
- moth balls (only one needed to kill)
Drugs where fetal risk > maternal risk
- Carbon Monoxide
- Methaemaglobin inducing agents
- napthalene
- dapsone (topical and oral antibiotic used to treat leprosy)
- lead
- salicylates
Anticholinergics
- Tachycardia, HTN
- normal respiration
- hyperthermia
- DILATED pupils
- quiet bowel sounds and urinary retention
- dry and red skin
- CNS altered, agitated/ hypervigilant
e.g
Atropine, scopalamine, benztropine
TCAs
some antihistamines –> chlorpromazine among others
Cholinergics
- No change in HR/BP, Respiration or temperature
- PINPOINT pupils
- Hyperactive bowel sounds
- Confusion/coma
SLUDGE ( hyperSalivation, Lacrimation, Urination, Diarrhoea, GI upset, Emesis)
e. g
- organophosphates
- mushrooms
- pesticides
- physostigmine
Opioids
- bradycardia, hypotension
- respiratory depression
- hypothermic
- PINPOINT pupils
- quiet bowel sounds and urinary retention
- Dry skin
- Drowsy/fluctuating GCS
e. g
- morphine
- codeine
- tramadol
- fentanyl
- methadone
- oxycodone
Sympathomimetics
- Tachycardia and HTN
- Tachypnoea
- Hyperthermia
- DILATED pupils
- Wet skin
- CNS altered/agitated
e. g
- Caffeine
- Cocaine
- amphetamines
- methamphetamines
- Ritalin
- MDMA
Sedative/hypnotic
- bradycardia and hypotension
- Respiratory depression
- Hypothermia
- NORMAL pupils
- Quiet bowel sounds
- Dry skin
e. g
- anti-anxiety medications
- muscle relaxants
- benzodiazepines
- barbituates
- other anti-seizure medications
Hallucinogens
- Tachycardia, HTN
- Normal Respiration
- Hyperthermia
- DILATED pupils (mydriasis)
- Hallucination, synesthsia, agitation, nystagmus
Antidote for Isoniazid
Pyridoxime
Antidote for Methemoglobinemia
Methylene blue
Antidote for CCBs
Calcium gluconate/chloride
Glucagon
Insulin/glucose
Antidote for Ethylene glycol (antifreeze)
Ethanol, Fomipazole
Antidote for Iron
Desferroximine
Antidote for Sulphonylureas (causes oral hypoglycemia)
Octreotide - inhibits insulin release