Anaesthetics Flashcards
How long before an operation should a patient be fasted of food and drink?
6 hours of no food or feeds before the operation
2 hours of no clear fluids (fully “nil by mouth”)
what is the biggest concern during rapid sequence induction?
aspiration of stomach contents into the lungs
what is the triad of anaesthesia?
Hypnosis
Muscle relaxation
Analgesia
State 3 IV hypnotic agents
Propofol (the most commonly used)
Ketamine
Thiopental sodium (less common)
State 2 inhaled hypnotic agents
Sevoflurane (the most commonly used)
Desflurane (less favourable as bad for the environment)
Isoflurane (very rarely used)
Nitrous oxide (combined with other anaesthetic medications – may be used for gas induction in children)
what are the 2 categories of muscle relaxant and give an example of each
Depolarising (e.g., suxamethonium)
Non-depolarising (e.g., rocuronium and atracurium)
what are the most common agents used for analgesia in anaesthetics?
Fentanyl
Alfentanil
Remifentanil
Morphine
state 3 prophylactic anti-emetics that may be given at the end of an operation and their contraindications
Ondansetron (5HT3 receptor antagonist) – avoided in patients at risk of prolonged QT interval
Dexamethasone (corticosteroid) – used with caution in diabetic or immunocompromised patients
Cyclizine (histamine (H1) receptor antagonist) – caution with heart failure and elderly patients
what drug can reverse the effect of non-depolarising relaxants?
Sugammadex
Name some significant risks of general anaesthesia
Accidental awareness (waking during the anaesthetic)
Aspiration
Dental injury
Anaphylaxis
Cardiovascular events
Malignant hyperthermia
Death
what are the features of malignant hyperthermia?
Increased body temperature (hyperthermia)
Increased carbon dioxide production
Tachycardia
Muscle rigidity
Acidosis
Hyperkalaemia
what drug is used to treat malignant hyperthermia?
dantrolene
name 3 procedures where a spinal anaesthetic may be used
Caesarean sections
Transurethral resection of the prostate (TURP)
Hip fracture repairs
state 3 adverse effects of an epidural
Headache if the dura is punctured, creating a hole for CSF to leak from (“dural tap”)
Hypotension
Motor weakness in the legs
Nerve damage (rare)
Infection, including meningitis
Haematoma (may cause spinal cord compression)
what is a common complication of mechanical ventilation?
Ventilator-associated lung injury
list the options for respiratory support from least to most invasive
Oxygen therapy
High-flow nasal cannula
Non-invasive ventilation
Intubation and mechanical ventilation
Extracorporeal membrane oxygenation (ECMO)
Acute respiratory distress syndrome presents with an acute onset of:
Collapse of the alveoli and lung tissue (atelectasis)
Pulmonary oedema (not related to heart failure or fluid overload)
Decreased lung compliance
Fibrosis of the lung tissue (typically after 10 days or more)
clinically what are the signs of acute respiratory distress?
Acute respiratory distress
Hypoxia with an inadequate response to oxygen therapy
Bilateral infiltrates on a chest x-ray
what is the management of ARDS?
Respiratory support
Prone positioning (lying on their front)
Careful fluid management to avoid excess fluid collecting in the lungs
Positive end-expiratory pressure
what is the concentration of oxygen via a nasal cannula?
24 – 44% oxygen
what is the concentration of oxygen via a simple face mask?
40 – 60% oxygen
what are inotropes?
medications that alter the contractility of the heart
what are vasopressors?
medications that cause vasoconstriction (narrowing of blood vessels). This increases the systemic vascular resistance and consequently mean arterial pressure (MAP)
state 4 indications for acute dialysis
A – Acidosis (severe and not responding to treatment)
E – Electrolyte abnormalities (treatment-resistant hyperkalaemia)
I – Intoxication (overdose of certain medications)
O – Oedema (severe and unresponsive pulmonary oedema)
U – Uraemia symptoms such as seizures or reduced consciousness
