Acute care

Question 1

Adverse effects of opioids (GOBS SC)

Answer 1

GI slowing - constipation, urinary retention
Opioid induced respiratory depression (with increased CO2 and possibly raised ICP)
Bradycardia
Strong addictive potential
Seizure threshold reduced
CNS depression (intensifies w benzo’s, alcohol)

Question 2

Effects of opioids (AG)

Answer 2

Analgesia
GI slowing

Question 3

Opioid receptor full agonists (MMM FC)

Answer 3

Morphine
Methadone
Meperidine
Codeine
Fentanyl

Question 4

Opioid receptor partial agonist (B)

Answer 4

Buprenorphine

Question 5

Opioid receptor full antagonists (NNM)

Answer 5

Naloxone
Naltrexone
Methylnaltrexone

Question 6

Difference between naloxone and naltrexone and clinical use

Answer 6

Naloxone - rapid action, short acting (half life 30-90mins, PO, IM, IV, SC, IO, intranasal)
Naltrexone - long acting (half life 4-10hrs, PO, IM)

Naltrexone used once detoxified to prevent opioid dependence relapse

Question 7

What is malignant hypothermia?

Answer 7

A subclinical myopathy - general anaesthesia triggers and uncontrollable contraction of skeletal muscle that leads to a life-threatening hypercatabolic state and an increase in body temperature

It is primarily autosomal dominant - mutations in receptors predispose to volatile anaesthetic agents or succinylcholine causing an accumulation of intracellular calcium in skeletal muscle that leads to its overactivation and hypermetabolism.

In acute setting - clinical diagnosis, increase in end-tidal CO2

Question 8

What is the treatment for malignant hypertension?

Answer 8

Dantrolene (ryanodine receptor antagonist - prevents release of calcium from the sarcoplasmic reticulum of striated muscle - reduced muscle rigidity and hyperthermia)

Question 9

Clinical presentation of DKA (DANK DF)

Answer 9

Delirium/psychosis
Abdominal pain
Nausea/vomiting
Kussmaul breathing
Dehydration
Fruity (acetone) breath

Question 10

Clinical presentation of HHS (DPP LFS)

Answer 10

Dehydration (profound)
Polydipsia
Polyuria
Lethargy
Focal neurological deficits
Seizures

Question 11

Diagnosis of DKA

Answer 11

Hyperglycemia
Anion gap metabolic acidosis (inc hydrogen ions, decreased HCO3)
Normal or increased serum K+ (decreased intracellular K+)
Hyperketonuria
Leukocytosis
No insulin

Question 12

Diagnosis of HHS

Answer 12

Elderly more susceptible
Insulin present
Hyperglycemia
Normal or increased serum K+ (decreased intracellular K+)
Normal serum pH and ketones

Question 13

Complications of DKA (CCHM)

Answer 13

Cerebral odema
Cardiac arrhythmias
Heart failure
Mucormycosis

Question 14

Complications of HHS (CD)

Answer 14

Coma
Death

Question 15

Treatment of DKA

Answer 15

Fluid resuscitation
Short acting IV insulin
Replacement of potassium
Glucose supplementation if needed

Question 16

Treatment of HHS

Question 17

Treatment of hyperkalemia

Answer 17

• Discontinue exogenous sources of potassium
• Treat reversible causes
• Calcium gluconate (stabilises cardiac membrane)
• Calcium chloride (only given in central venous lines as irritating to peripheral vessels)
• Insulin and glucose (usually 10 units of regular insulin given with 50ml of a 50% dextrose solution)
• B2 adrenergic agents (such as albuterol) will also shift potassium intracellularly - usually given at much higher doses than commonly used for bronchodilation
• Loop or thiazide diuretics may help enhance potassium excretion

Question 18

Definition of hyperkalemia

Answer 18

Serum plasma potassium above upper limit of normal
- Usually 5.0mEq/L to 5.5mEq/L

Question 19

ECG signs of hyperkalemia based on K concentration

Answer 19

• K= 5.5 to 6.5 will show tall, peaked T waves
• K= 6.5 to 7.5 will show loss of p waves
• K= 7 to 8 will show widening of QRS complex
• K= 8 to 10 will produce cardiac arrhythmias, sine wave pattern and asystole

Question 20

Clinical features of hyperkalemia

Answer 20

• Weakness
• Fatigue
• Palpitations
• Syncope
• Mild hyperkalemia is usually asymptomatic
• Symptoms usually develop around 6.5 to 7mEq/L
• May be asymptomatic with chronic hyperkalemia
• Hypertension in renal failure

Question 21

Complications of hyperkalemia treatment

Answer 21

• Hypokalemia
• Hypocalcemia as a result of bicarbonate infusion
• Hypoglycemia due to insulin
• Metabolic alkalosis from bicarbonate therapy
• Volume depletion from diuresis

Question 22

Common inhalational anaesthetics

Answer 22

Nitrous oxide
Desflurane
Sevoflurane

Question 23

Effects of inhalational anaesthetics

Answer 23

• Sedation/narcosis
• Decreased respiration and arterial BP, myocardial depression
• Increased cerebral flow and ICP

Question 24

Risks of inhalational anaesthetics

Answer 24

• Post op N+V
• Malignant hyperthermia

Question 25

Common IV anaesthetics

Answer 25

- Propofol - Ketamine - Etomidate - Opioids (fentanyl, morphine) - Benzodiazepines (midazolam) - Barbituates (thiopental and methohexital)

Question 26

Propofol indications

Answer 26

- Total IV anaesthesia drug of choice - Rapid sequence induction - Sedation in ICU - Short procedures

Question 27

Propofol MOA and effects

Answer 27

- Agonist on Na channels of the reticular formation agonist on GABAa receptors and an antagonist on NMDA receptors - leading to decreased ICP, global CNS depression and hypnotic, antiemetic and anticonvulsant effects - No analesic or muscle relaxant effects

Question 28

Ketamine MOA and effects

Answer 28

NMDA receptor antagonist - Dissociative anaesthesia, sympathomimetic effects, increased cerebral blood flow

Question 29

Adverse effects of opioids

Answer 29

- Muscle rigidity - CVS and respiratory depression

Question 30

Adverse effects of benzodiazepines

Answer 30

- Anterograde amnesia - Decreased BP - Can cause severe respiratory depression

Question 31

Indications for benzodiazepines in anaesthesia

Answer 31

- IV anasthesia induction - Short outpatient procedures - Preoperative sedation - Endoscopy

Question 32

Benzodiazepine MOA

Answer 32

- Indirect GABAa receptor antagonism - leads to decreased neuronal excitability

Question 33

Atropine MOA and uses

Answer 33

- Anticholinergic that competitively blocks muscarinic acetylcholine receptors - Used to treat acute symptomatic bradycardia or AV block, decrease salivation, reverse neuromuscular blockade and reverse organophosphate poisioning

Question 34

Paracetamol overdose definition for adults and children

Answer 34

- >7.5g for adults - >150mg/kg for children

Question 35

Paracetamol overdose treatment

Answer 35

- N-acetylcysteine (anti-oxidant that restores depleted hepatic glutathione in patients with paracetamol overdose)

Question 36

Cardiac causes of chest pain

Answer 36

STEMI NSTEMI Unstable angina Aortic dissection Cardiac tamponade Pericarditis HF exacerbation Thoracic aortic aneurysm Takotsubo cardiomyopathy

Question 37

Pulmonary causes of chest pain

Answer 37

Pulmonary embolism Tension pneumothorax Pneumonia Spontaneous pneumothorax Asthma exacerbation COPD exacerbation Pleural effusion

Question 38

GI causes of chest pain

Answer 38

GORD Erosive oesophagitis Gastritis PUD Pancreatitis Mallory-weiss tear Esophageal hypermotility disorders