Anaesthesia for emergency surgery Flashcards
Classify and give examples for the theatre triage system used at GSH
RED (< 1hr)
- Unstable bleeding GSW
- Ruptured ectopic
- Ruptured AAA
- Imminently threatened airway
ORANGE (1 - 3 hrs)
- Acute abdomen (bowl perforation)
- Threatened rupture of ectopic
YELLOW (< 6hrs)
- Stable appendix
- Open fractures
GREEN (<24 hrs)
- Closed fractures
- Changing of dressings
- Cancer surgery
BLUE
- Elective surgery (cataract / tonsillectomy etc)
Describe the ASA fasting guidelines
Clear fluids - 2 hours
Breast milk - 4 hours
Non-human milk - 6 hours
Solids - 6 hours
What is Mendelson’s syndrome
Aspiration of stomach contents into the respiratory system
Vomiting/regurgitation of stomach content, fluid, particulate matter into the trachea may cause hypoxia by both mechanical obstruction and an acute pulmonary inflammatory process (chemical pneumonitis) –> may progress to atelectasis and infection.
Differentiate vomiting from regurgitation in the context of Mendelson’s syndrome
Vomiting
- Active process
- Lighter planes of anaesthesia (induction/emergeance)
- expulsion of gastric contents into pharynx by contraction of the diaphragm
Regurgitation
- Passive process
- Occurs at any time - deeper planes
- Laryngeal reflexes are reduced or paralysed
In the context of anaesthetics classify the situations during which it is assumed that there is a full stomach
INTAKE
- recent fluid/solid intake
ABNORMAL PERISTALSIS
- Peritonitis
- Ileus
- —–> Postoperative
- —–> Metabolic (hypoK, Uraemia, DKA)
- —–> Drug induced (Opioids/anticholinergics)
OBSTRUCTED PERISTALSIS
- Gastric Ca
- Pyloric stenosis
- Obstruction (Small or large bowel)
DELAYED GASTRIC EMPTYING
- Shock
- Trauma
- Diabetes
- Pregnancy and labour
- Fear/pain/anxiety
- Opioids
Why is prolonged muscle relaxation more common in emergency (vs elective) surgery
- Hypothermia
- Electrolyte abN
- Drug interactions
- Reduced clearance d/t impaired hepatic/renal fxn
In a patient in whom RSI was performed, what is paramount during emergence of this patient
PREVENT ASPIRATION
- Adequate reversal
- Breathing spontaneously (FiO2 < 0.4 and SaO2 > 95%)
- Suctioned oro and nasopharynx
- Fully awake: responds to verbal commands (open eyes/nods or lifts head)
Once all the above are confirmed - Remove ETT during a manual positive pressure breath.
Differentiate primary and secondary brain injury
Primary
- Irreversible injury of neural/supportive/vascular tissues
Secondary
- Following primary injury, the injured brain is susceptible in the following days to events that would have no effect on normal brain tissue
1. Hypoxia
2. Hypotension
3. Hyperthermia
4. Convulsions
5. Hyper and hypoglycaemia
Describe the targets with regard to the prevention of secondary brain injury
Airway
- Intubate if GCS < 8
- Remember C-spine (manual in-line)
Breathing
- SaO2 > 95%
- Normocapnoea
Circulation
- MAP > 90mmHg
Rx SBP < 90 mmHg aggresively
Disability
- Seizure prophylaxis: Phenytoin 20mg/kg load
Exposure
- Maintain normothermia
Fluid
- Mannitol 0.5mg/kg if deteriorating neurological status with catherter in situ
- NaCl is hypertonic therefore fluid of choice
Glucose
- Maitain euglycaemia
What is the formula for cerebral perfusion pressure (CPP)§
CPP = MAP - ICP or CVP (whichever is greater)
Describe when and how mannitol is given in TBI
Deteriorating neurology (decreasing LOC with localizing signs)
Dose: 0.5 mg/kg (± 200 ml of mannitol 20%)
Urinary catheter in situ
May repeat the same dose if further neurological deterioration occurs
