Anaesthetics/Acute care Flashcards
What is seen on CXR with diaphragm rupture?
Indistinct hemidiaphragm
Bowel loops in thorax
Displacement of mediastinum
-> surgical repair
What is flail chest?
When chest wall disconnects from thoracic cage, usually due to multiple rib fracs
Assoc w pulmonary contusion
Abnormal chest movement
Avoid over-hydration/fluid overload
What is seen on CXR with aortic rupture from deceleration injury?
If no sign on CXR when should it be suspected?
What test then?
- widened mediastinum
- depression of bronchus/tracheal deviation
Presence of persistent hypotension - contained haematoma formation - but lung markings at peripheries (so not tension pneumo)
CT angio
Propofol:
- MOA?
- Onset?
- Positive extra effect?
- Negative effects?
- Main uses?
- GABA receptor agonist
- Rapid onset, rapidly metabolised with little accumulation
- Anti-emetic
- Myocardial depression, pain at IV site
- Maintaining sedation in ITU,, total IV anaesthesia and daycare surgery
Sodium Thiopentone:
- MOA
- Onset?
- Negative effects?
- Use?
- Useful for maintenance infusion?
- A type of barbiturate (potentiates GABAa)
- Rapid onset
- Metabolites build up quickly, marked myocardial depression, little analgesic effect
- Rapid sequence induction
- No
Ketamine:
- MOA?
- Positive effects?
- Negative effects?
- Uses?
- NMDA antagonist
- Strong analgesia, very little myocardial depression
- Nightmares
- Induction of anaesthesia and when haemodynamically unstable
Etomidate
- MOA?
- what is it useful in?
- Negative effects?
- Potentiates GABAa
- Safe in cardiac disease or haemodynamically stable
Negatives:
- No analgesia
- May cause adrenal suppression
- Post-op vomiting common
- Myoclonus
Why is end tidal CO2 measured in ET tube?
To ensure not in oesophagus
Why is humidified air used in tracheostomy?
Where is it widely used?
- dries secretions of throat
- ITU
What is commonly used for day surgery?
Is it suitable for high pressure ventilation (PEEP)?
Does it control gastric contents?
Laryngeal mask
Not suitable for PEEP
No control of gastric contents
What provides optimal airway management?
ET tube
What anaesthetic agent is hepatotoxic?
Halothane - should be avoided in hepatic dysfunction
What surgeries are guaranteed to have a high blood loss and require cross match 4-6 units? (6)
- Total gastrectomy
- Oophorectomy
- Oesophagectomy
- Elective AAA repair
- Cystectomy
- Hepatectomy
What surgeries require cross match 2 units blood as high likelihood of requiring transfusion? (2)
- Salpingectomy for ruptured ectopic
- THR
Adverse effects of volatile liquid anaesthetics?
- Myocardial suppression
- Malignant hyperthermia
- Halothane: hepatotoxic
Used for induction and maintenance of anaesthesia
Negative effects of NO anaesthetic?
When should it be avoided?
Uses?
May diffuse into gas-filled body compartments and increase pressure
Avoid in e.g. pneumothorax
Maintenance of anaesthesia and analgesia (labour)
Features of central lines?
Multiple lumens, so useful for multiple infusions
Lumens are narrow though so don’t allow fast rate of infusion
IJV preferred but slightly more difficult
Femoral easier access but more prone to infection
Where are intraosseous lines mostly used?
Paeds
When are tunnelled lines e.g. Hickmans used?
What actually are they?
Useful for patients requiring long-term therapeutics
Inserted into IJV and tunnelled under skin and anchored to tissues. Can have injection port under the skin
What is a PICC line?
Peripherally inserted central cannula
Popular for establishing central venous access - inserted peripherally so less prone to major complications than conventional central lines
Problems with PVC’s?
Why are they good?
Unsuitable for administration of vasoactive drugs e.g. inotropes, or irritants e.g. TPN (except in very short term)
Wide lumen so good for rapid infusion
Size order of PVC’s smallest to largest?
Blue Pink Green Grey Orange
Lidocaine:
- MOA?
- drug interactions?
- toxicity?
Blocks Na channels in axons
B blockers, ciprofloxacin, phenytoin (as hepatic ally metabolised)
Toxicity: CNS overactivity ten depression, cardiac arrhythmias
Rx: IV 20% lipid emulsion
When is adrenaline CI to be added to local anaesthetic?
Why is it used?
- End arteries e.g. fingers
- Pt taking MAOI or tricyclic antidepressants
Prolongs duration of action and allows much higher doses
Presentation of malignant hyperthermia? Why does it happen? Causative agents? Ix? Rx?
- Hyperpyrexia and muscle rigidity following administration of anaesthetic
- AD inherited trait from Chr19 - causes excessive release of Ca2+ from sarcoplasmic reticulum of skeletal muscle
- Halothane and suxamethonium
- CK raised
Contracture test with halothane and caffeine
Dantrolene (prevents Ca2+ release from SR)
(also happens with antipsychotics - may have similar aetiology)
When are nasopharyngeal airways useful for?
When can they not be used?
Pt having seizure - cannot use oropharyngeal
Well tolerated in low GCS
Basal skull fractures
When is suxamethonium contraindicated and why?
Penetrating eye injuries or acute close angle glaucoma - increases intra-ocular pressure
Example of a polarising NM blocker? MOA? Adverse effects? When is it used? Reversal?
Suxamethonium
Binds nicotinic Each receptors, causing persistent depolarisation of the motor end plate
Malignant hyperthermia
Transient hyperkalaemia
Fasciculations
Muscle relaxant of choice for rapid sequence induction
No reversal