Toxicology and overdose Flashcards
Alcohol: signs and symptoms
Nausea, vomiting, slurred speech, confusion, ataxia, convulsions, unconsciousness, hypotension, hypoglycaemia
alcohol intoxication: pathophysiology
following the consumption of excessive amounts of alcohol Alcohol is broken down in the liver into acetaldehyde which is then broken down into acetate, when excessive alcohol is consumed this system is overwhelmed and toxic levels of acetaldehyde are present in the blood. this depresses the nervous system and effects metabolism. It can be fatal and is a common emergency.
Alcohol: management
measure and correct blood glucose levels
avoid some drugs as are dangerous in combination with alcohol
recovery position
manage Airway and breathing
Benzodiazepines: signs and symptoms
decreased level of consciousness
respiratory depression (uncommon)
hypotension
slurred speech
ataxia
hypothermia
decreased reflexes
respiratory depression
benzodiazepines: management
consider activated charcoal
antidote = flumazenil every 20 mins
only use flumazenil in accidental overdoses
Manage CABCDE and correct
Cocaine: signs and symptoms
hyperexcitable
agitated
irritable and sometimes violent
sweating
dilated pupils
Cocaine: pathophysiology
cocaine blocks the reuptake of dopamine neurotransmitter in the mid brain which causes euphoria and excitement. this blocking prevents noradrenaline uptake causing vasoconstriction and hypertension. crack/cocaine can also cause coronary artery spasm which can lead to MI, AF and ischemic heart disease.
Cocaine: management
Manage airway and breathing
assisted ventilation if low O2 or RR above 30.
aspirin and GTN for chest pain
cooling if hyperthermic
Urgent transfer if swallowed crack cocaine even if asymptomatic
Opioids: signs and symptoms
drowsiness
nausea
vomiting
small pupils
respiratory depression
cyanosis
decreased level of consciousness
convulsions
pulmonary oedema(non cardiac)
Opioids: pathophysiology
Bind to MU receptors in the brain, spinal cord and - to depress the central nervous system and inhibit pain signals and stimulate dopamine release to produce a feeling of euphoria. Activation of MU receptors produce a depressed medullary response to hypercarbia and hypoxia decreasing the reflex to breath and often overdose is fatal due to respiratory depression. Opiates can also cause bronchoconstriction leading to wheezing and dyspnoea.
Opioids: management
Maintain airways and give O2 if needed
Antidote = naloxone
Naloxone - IV,IM, IN can cause agitation and violence (give lowest dose if addiction is implied) 0.4-1mh in adults
activated charcoal to
decontaminate GI tract
Paracetamol: signs and symptoms
nausea/vomiting
malaise
RUQ abdo pain
jaundice
confusion
drowsiness
frequently ASYMPTOMATIC
Paracetamol: pathophysiology
paracetamol is a cyclooxygenase 2 inhibitor which inhibits the synthesis of prostaglandins, these are lipids which produce the sensation of pain. when metabolised in the liver in large quantities, the liver loses its detoxifying properties and hepatic necrosis occurs leading to liver damage and failure.
paracetamol: management
if taken in last 60 mins - activated charcoal
determine dose by asking about medications as many contain paracetamol
naloxone if respiratory depression
manage airways and breathing
transfer even if asymptomatic as effects can take 24-48 hours
never encourage vomiting
types of exposure
accidental
intentional
deliberate by a third party
major CABCDE problems in overdose
cardiac/respiratory arrest
decreased level of consciousness
arrythmias
convulsions
hypothermia
assessments for overdose
blood pressure
ECG
blood glucose
respiration
substance taken - skin checks, mouth checks, history, environment
temperature
mental health - expectation of outcome
