Unconsciousness
With a patient presenting with impaired consciousness, what would be a critical initial assessment?
A->Es
Obs
GCS!!!!! Pupils, BGL
A patient presents agitated and hyperthermic after cocaine use. Blood tests reveal hypernatremia.
Explain how stimulant intoxication may lead to hypernatremia.
Excess insensible water loss
Reduced water intake
Increased sympathetic activity
Result
What is the MOA of cocaine?
What is the reversal agent for opioid overdose?
Naloxone: competitive opioid receptor antagonist
How do nerves and muscles contribute to the physiology of pupil constriction and dilation?
Constriction (miosis)
Dilation (mydriasis)
List the causes of unconsciousness
Alcohol / Acidosis
Epilepsy / Electrolytes / Environment (e.g., hyper/hypothermia)
Insulin (hyperglycemia or hypoglycemia)
Overdose / Oxygen deficiency (hypoxia)
Uremia (kidney failure buildup)
Trauma / Temperature
Infection (e.g., sepsis, meningitis)
Psychiatric / Poisons
Stroke / Seizures / Shock / Syncope
A patient presents following a heroin overdose with reduced consciousness and respiratory depression. Blood tests later show hyponatraemia.
Explain how opioid overdose may contribute to hyponatraemia.
Clinical consequences
What receptors do opioids bind to and how does that binding cause an effect?
Opiates are μ (mu) receptor agonists
Binding causes:
Net effect:
What are two tests you should do in every overdose?
Explain how dysfunction of the reticular activating system (RAS), thalamus and cerebral cortex can each independently produce altered conscious states.
Reticular Activating System (RAS)
Role:
RAS dysfunction:
Thalamus
Role:
Thalamic dysfunction:
Cerebral Cortex
Role:
Diffuse bilateral cortical dysfunction:
Define Delirium, consciousness, coma, brain death
Consiousness: Self-awareness, Access to memories, Ability to manipulate abstract ideas, Focus of attention
Delirium: Acute condition with altered mental state, organic basis, syndrome
Coma: Unrousable unresponsivenss, no response to pain
Brain death: Irreversible loss of brain death, no brainstem reflexes, **not in low temp/drugs**
A patient presents with severe vomiting, hypotension and tachycardia. Blood tests show hyponatraemia.
Explain why this patient activates both ADH secretion and the renin–angiotensin–aldosterone system (RAAS), and describe how these responses affect sodium and water balance.
ADH effects
RAAS effects
What is the MOA of benzodiazepines?
Effects:
What are the reversible causes of unconsciousness?
1. Hypovolaemia, hypoxia, H+ (acidosis), hyper./hypokalaemia, hypoglycaemia, hypothermia
2. Toxins, tamponade, tension pneumothorax, thrombosis, trauma
A patient opens their eyes to a painful stimulus, speaks using inappropriate words, and withdraws their arm when you apply pain. What is their GCS score and how is it written?
GCS = 9 E2V3M4
Explain why hypoglycaemia causes altered conscious state.
Explain why hypernatremia causes neurological symptoms and compare this mechanism with neurological dysfunction in hyponatraemia.
Key comparison
What are four effects of opioids in the CNS?
Compare and contrast opioid toxicity, benzodiazepine toxicity and serotonin syndrome with reference to receptor pharmacology, neurotransmitter effects and clinical manifestations.
Opioid toxicity results from μ-opioid receptor agonism causing inhibition of neuronal activity through reduced cAMP production, potassium efflux and decreased neurotransmitter release, producing profound respiratory depression, miosis and reduced consciousness. Benzodiazepine toxicity occurs through potentiation of GABA-A receptor activity by increasing the frequency of chloride channel opening, leading predominantly to sedation, anxiolysis and CNS depression, with less severe respiratory depression unless combined with other sedatives such as opioids. In contrast, serotonin syndrome is caused by excessive serotonergic activity at 5-HT receptors, producing a hyperactive state characterised by agitation, hyperthermia, hyperreflexia and clonus rather than the sedative features seen in opioid or benzodiazepine overdose.
At follow up the patient reports back pain and is prescribed tramadol. What is the main drug interaction you would be worried about with this patient?
Why:
Features:
Other concern:
An unconscious patient is brought to the emergency department after suspected polysubstance overdose. Initial assessment reveals hypotension, tachycardia, dry mucous membranes and hypernatremia.
Explain the pathophysiological mechanisms contributing to the patient’s hypernatremia and reduced level of consciousness.
A patient with SIADH is hyponatraemic despite having normal total body sodium.
Explain the mechanism responsible for hyponatraemia in SIADH and why the patient is usually clinically euvolaemic.
Why euvolaemic?
What is the management for Alcohol use disorder?
1. Motivational enhancement (MET)
2. Psychotherapy referral (CBT)
3. Motivational interviewing (Using FLAGS)
4. Meds: Disulfiram, naltrexone
Explain why co-ingestion of opioids and benzodiazepines significantly increases mortality in overdose patients compared with either drug alone.
Opioids and benzodiazepines both depress central nervous system activity but act through different receptor systems, producing synergistic rather than merely additive respiratory depression. Opioids suppress medullary respiratory centres through μ-opioid receptor agonism, reducing respiratory rate and responsiveness to carbon dioxide, while benzodiazepines potentiate GABA-A receptor activity, further depressing neuronal excitability, consciousness and airway protective reflexes. Together, these effects markedly increase the risk of hypoventilation, hypoxia, aspiration, coma and death, particularly because sedation may delay recognition of respiratory compromise until severe cerebral hypoxia has already developed.
What are some symptoms of burn-out that doctors may experience (2marks)
What are three things a junior doctor's supervisor can do to help with this burnout? (1.5 marks)
1. Emotional exhaustion, depersonalisation, diminished sense of self worth. Primarily driven by workplace stressors and excessive workload
Actions
1. Workload modifications, rest breaks
2. Mentorship & well-being check ins. Clinical supervisor
3. Refer to EAP (employee assistant program)