Acute care Flashcards
Adverse effects of opioids (GOBS SC)
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)
Effects of opioids (AG)
Analgesia
GI slowing
Opioid receptor full agonists (MMM FC)
Morphine
Methadone
Meperidine
Codeine
Fentanyl
Opioid receptor partial agonist (B)
Buprenorphine
Opioid receptor full antagonists (NNM)
Naloxone
Naltrexone
Methylnaltrexone
Difference between naloxone and naltrexone and clinical use
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
What is malignant hypothermia?
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
What is the treatment for malignant hypertension?
Dantrolene (ryanodine receptor antagonist - prevents release of calcium from the sarcoplasmic reticulum of striated muscle - reduced muscle rigidity and hyperthermia)
Clinical presentation of DKA (DANK DF)
Delirium/psychosis
Abdominal pain
Nausea/vomiting
Kussmaul breathing
Dehydration
Fruity (acetone) breath
Clinical presentation of HHS (DPP LFS)
Dehydration (profound)
Polydipsia
Polyuria
Lethargy
Focal neurological deficits
Seizures
Diagnosis of DKA
Hyperglycemia
Anion gap metabolic acidosis (inc hydrogen ions, decreased HCO3)
Normal or increased serum K+ (decreased intracellular K+)
Hyperketonuria
Leukocytosis
No insulin
Diagnosis of HHS
Elderly more susceptible
Insulin present
Hyperglycemia
Normal or increased serum K+ (decreased intracellular K+)
Normal serum pH and ketones
Complications of DKA (CCHM)
Cerebral odema
Cardiac arrhythmias
Heart failure
Mucormycosis
Complications of HHS (CD)
Coma
Death
Treatment of DKA
Fluid resuscitation
Short acting IV insulin
Replacement of potassium
Glucose supplementation if needed
Treatment of HHS
Treatment of hyperkalemia
- 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
Definition of hyperkalemia
Serum plasma potassium above upper limit of normal
- Usually 5.0mEq/L to 5.5mEq/L
ECG signs of hyperkalemia based on K concentration
- 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
Clinical features of hyperkalemia
- 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
Complications of hyperkalemia treatment
- Hypokalemia
- Hypocalcemia as a result of bicarbonate infusion
- Hypoglycemia due to insulin
- Metabolic alkalosis from bicarbonate therapy
- Volume depletion from diuresis
Common inhalational anaesthetics
Nitrous oxide
Desflurane
Sevoflurane
Effects of inhalational anaesthetics
- Sedation/narcosis
- Decreased respiration and arterial BP, myocardial depression
- Increased cerebral flow and ICP
Risks of inhalational anaesthetics
- Post op N+V
- Malignant hyperthermia
Common IV anaesthetics
- Propofol
- Ketamine
- Etomidate
- Opioids (fentanyl, morphine)
- Benzodiazepines (midazolam)
- Barbituates (thiopental and methohexital)
Propofol indications
- Total IV anaesthesia drug of choice
- Rapid sequence induction
- Sedation in ICU
- Short procedures
Propofol MOA and effects
- 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
Ketamine MOA and effects
NMDA receptor antagonist
- Dissociative anaesthesia, sympathomimetic effects, increased cerebral blood flow
Adverse effects of opioids
- Muscle rigidity
- CVS and respiratory depression
Adverse effects of benzodiazepines
- Anterograde amnesia
- Decreased BP
- Can cause severe respiratory depression
Indications for benzodiazepines in anaesthesia
- IV anasthesia induction
- Short outpatient procedures
- Preoperative sedation
- Endoscopy
Benzodiazepine MOA
- Indirect GABAa receptor antagonism - leads to decreased neuronal excitability
Atropine MOA and uses
- 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
Paracetamol overdose definition for adults and children
- > 7.5g for adults
- > 150mg/kg for children
Paracetamol overdose treatment
- N-acetylcysteine (anti-oxidant that restores depleted hepatic glutathione in patients with paracetamol overdose)
Cardiac causes of chest pain
STEMI
NSTEMI
Unstable angina
Aortic dissection
Cardiac tamponade
Pericarditis
HF exacerbation
Thoracic aortic aneurysm
Takotsubo cardiomyopathy
Pulmonary causes of chest pain
Pulmonary embolism
Tension pneumothorax
Pneumonia
Spontaneous pneumothorax
Asthma exacerbation
COPD exacerbation
Pleural effusion
GI causes of chest pain
GORD
Erosive oesophagitis
Gastritis
PUD
Pancreatitis
Mallory-weiss tear
Esophageal hypermotility disorders
