ANAESTHETICS Flashcards
(53 cards)
PRE-OP ASSESSMENT
how can you remember the important medications for medication history in a pre-op assessment?
CASES
- contraception
- anticoagulation
- steroids
- ethanol
- smoking
PRE-OP ASSESSMENT
which elements of a medication history are often missed?
- over the counter medications
- non-oral medicines (e.g. eye drops, creams or inhalers)
- oral contraceptives
- complementary + alternative therapies
- borderline substances (vitamins, food supplements)
- illicit substances
NIL-BY-MOUTH
what are the rules for nil-by-mouth before elective surgery?
- restrict oral solids 6hrs before srugery
- allow water + clear fluids until 2hrs before surgery
- allow routine medications with clear fluids until 2 hrs before operation
VRIII
which patients are most likely to benefit from VRIII insulin?
- prolonged periods of starvation (more than one meal missed)
- no or unknown postoperative enteral absorption
- labile blood sugars or HbA1c >69
- T1DM undergoing major surgery
- T1DM who have not received background insulin
- infection
- most patients with DM requiring emergency surgery require VRIII
VRIII
when can a VRIII be withdrawn?
once a patient is eating and drinking normally without nausea and vomiting
VRIII
if VRIII is not used, what are the instructions for the following oral hypoglycaemic agents:
a. sulphonylureas (e.g. gliclazide)
b. pioglitazone
c. DPP4 inhibitors (e.g. sitagliptin)
sulphonylureas (gliclazide) = omitted on morning of surgery
pioglitazone = taken as normal on day of surgery
DPP4 inhibitors (sitagliptin) = taken as normal on day of surgery
MALIGNANT HYPERTHERMIA
what is it>
condition often seen after administration of anaesthetic agents
characterised by hyperpyrexia + muscle rigidity
MALIGNANT HYPERTHERMIA
what is it associated with?
gene defect on chromosome 19
it is autosomal dominant inherited
MALIGNANT HYPERTHERMIA
what are the causative agents?
- halothane
- suxamethonium
- antipsychotics (neuroleptic malignant syndrome)
MALIGNANT HYPERTHERMIA
what are the investigations?
CK = raised
- contracture tests with halothane + caffeine
MALIGNANT HYPERTHERMIA
what is the management?
dantrolene
HYPOTHERMIA
what is it?
mild = 32-35 degrees
moderate/severe = <32 degrees
HYPOTHERMIA
what are the potential causes?
- exposure to cold in environment
- inadequate insulation in operating room
- cardiopulmonary bypass
- newborn babies
HYPOTHERMIA
what are the risk factors?
- general anaesthetic
- substance misuse
- hypothyroidism
- impaired mental status
- homelessness
- extremes of age
HYPOTHERMIA
what are the clinical features?
- shivering
- cold + pale skin
- slurred speech
- tachypnoea, tachycardia + HTN (if mild)
- respiratory depression, bradycardia + hypotension (if moderate)
- confusion/impaired mental state
HYPOTHERMIA
what are the investigations?
- temperature
- 12 lead ECG = J waves + osborn waves
- FBC, U&Es
- blood glucose
- ABG
- coagulation factors
- CXR
HYPOTHERMIA
what is the management?
- remove patient from cold environment + remove cold/wet clothes
- warm with blankets
- secure airway + monitor breathing
- use warm IV fluids + forced warm air to body
HYPOTHERMIA
what should you not do in patients with hypothermia?
- don’t put person in hot bath
- don’t massage their limbs
- don’t use heating lamps
- don’t give them alcohol to drink
AIRWAY MANAGEMENT
what are the different manoeuvres to open the airway?
- head tilt/chin lift
- jaw thrust (preferred if concern about cervical spine)
AIRWAY MANAGEMENT
what different devices can be used for airway management?
- oropharyngeal airway
- nasopharyngeal airway
- laryngeal mask (i-gel)
- tracheostomy
- endotracheal tube
AIRWAY MANAGEMENT
what are the pros and cons of oropharyngeal airways?
- easy to insert + use
- no need for paralysis
- ideal for very short procedures
- most often used as a bridge to more definitive airway
AIRWAY MANAGEMENT
what are the pros and cons of laryngeal masks?
PROS
- very easy to insert
- paralysis not required
- widely used
CONS
- poor control against reflux of gastric contents
- not suitable for high pressure ventilation
AIRWAY MANAGEMENT
what are the pros and cons of tracheostomy?
PROS
- reduces work of breathing
- may be useful for slow weaning
CONS
- dries secretions so humidified air is often required
AIRWAY MANAGEMENT
what are the pros and cons of endotracheal tubes?
PROS
- provides optimal control of airway once cuff is inflated
- may be used for both short and long term ventilation
- higher ventilation pressures can be used
CONS
- errors in insertion can result in oesophageal intubation
- paralysis often required
