Anaesthetics Flashcards
What are 3 simple maneuvers that can relieve the majority of airway obstruction secondary to poor pharyngeal muscle tone?
Head tilt, chin lift, jaw thrust
Describe a oropharyngeal airway
Easy to insert and use
No paralysis required
Ideal for very short procedures
Most often used as a bridge to a more definitive airway
Describe a laryngeal mask
Widely used
Very easy to insert
Device sits in the pharynx and aligns to cover the airway
Poor control against reflux of gastric contents
Paralysis not usually required
Commonly used for a wide range of anaesthetic uses, especially in day surgery
Not suitable for high pressure ventilation
Describe a tracheostomy
Reduces work of breathing and dead space
May be useful in slow weaning
Widely used in ITU
Dries secretions, humidified air as required
Describe an endotracheal tube
Provides optimal control of the airway once the cuff is inflated
May be used for short term or long term ventilation
Errors in insertion may lead to oesophageal insertion (therefore end tidal CO2 usually measured)
Paralysis often required
Higher ventilation pressures can be used
Criteria for brain death
Fixed pupils which don’t respond to sharp changes in the intensity of the incident of light
No corneal reflex
Absent oculo-vestibular reflexes (no eye movements following insertion of cold water into ear - caloric test)
No response to supraorbital pressure
No cough reflex to bronchial stimulation or gagging response to pharyngeal stimulation
No observed resp effort in response to disconnection of the ventilator long enough (typically 5 mins)
What is a condition seen after administration of anaesthetic agents?
Malignant hyperthermia
Presentation of malignant hyperthermia
Hyperpyrexia
Muscle rigidity
Pathology of malignant hyperthermia
Excessive Ca2+ release from the sarcoplasmic reticulum of skeletal muscles
Associated with a gene defect on chromosome 19 encoding the ryanodine
Susceptibility is in an autosomal dominant fashion
Causative agents of malignant hyperthermia
Halothane
Suxamethonium
Antipsychotics (neuroepileptic malignant syndrome)
Investigations of malignant hyperthermia
Raised CK
Contracture tests with halothane and caffeine
Management of malignant hyperthermia
Dantrolene
How does dantrolene work?
Prevents Ca2+ release from the sarcoplasmic reticulum
What is suxamethonium?
Depolarising muscle relaxant
Example of action to take about blood transfusion if about to have a procedure where chance of transfusion is unlikely
Group and save
Examples of operations which are unlikely to have a blood transfusion
Simple hysterectomy Appendectomy Thyroidectomy Elective lower segment caesarean section Laparoscopic cholecystectomy
Example of action to take about blood transfusion if an operation has a likely chance of infusion
Cross match 2 units
Example of operations which are likely to have a chance of blood transfusion
Salpingectomy for ectopic pregnancy
Total hip replacement
Example of action to take about blood transfusion if an operation has a definite need of blood transfusion
Cross match 4 - 6 units
Examples of operations that have a definite need for blood transfusion
Total gastrectomy Oophrectomy Oesophagectomy Elective AAA repair Cystectomy Hepatectomy
Treatment of malignant hyperthermia
Dantrolene
What is the muscle relaxant of choice for rapid sequence induction for intubation?
Suxamethonium
Most likely cause of post op fever day 1 - 2
WIND
- pneumonia
- aspiration
- PE
Most likely cause of post op fever day 3 - 5
UTI (esp if was catheterised)
