Mod 9b: rapid sequence induction Flashcards
True or false: trauma/pain will halt gastric emptying
True
What is Mendelson’s syndrome
chemical pneumonitis caused by aspiration during anaesthesia.
Aspiration of vomited/regurgitated gastric contents occurs with loss of laryngeal reflexes
Fluid particulate matter in the trachea may cause bronchopulmonary reaction
What are the clinical features of aspiration?
Occurs 2-5 hours after anaesthesia:
Cyanosis
Dyspnoea
Wheeze + crackles
Hypoxia
Tachycardia + high BP
What is the difference between vomiting and regurgitation?
Vomiting is an active process which occurs in lighter planes of anaesthesia usually in induction and emergence
Regurgitation is PASSIVE:
at any time, silent
Usually in deeper planes of anaesthesia
LARYNGEAL REFLEXES ARE REDUCED
What are some risk factors for aspiration?
Full stomach
Abdominal masses
*Morbid Obesity BMI > 30
*Ascites
*Tumours
Gastric Pathology
*Gastritis
Pregnancy
Emergency and Trauma
Airway Trauma
Decreased GCS
Pain and opiates
When do we assume a full stomach/
Absent/abnormal peristalsis(Ileus):
- post-op
- metabolic (DKA, uraemia, hypokalaemia)
-Drug induced: opiods, anticholinergics
Obstruction:
- bowel obstruction
- Gastric CA
- Pyloric stenosis
Delayed gastric emptying:
- shock
- diabetes
- trauma
- pregnancy
- fear, pain, anxiety
How do you prevent aspiration?
Empty stomach:
- Delay surgery
- NGT & Suction
- prokinetics
Neutralise the stomach acid:
Antacids: sodium citrate
H2 blockers
PPIs-omeprazole
Avoid GA if possible
RSI
What is the immediate management of aspiration?
80-100% O2
Minimise risk further:
- left lateral position, head down, oropharyngeal suncion before ventilation
ETT if ventilation/suctioning required
What is the further management of aspiration after immediate management?
Treat as foreign body:
- minimise positive pressure ventilation
- Possible bronchoscopy
NGT to empty stomach
Monitor resp function
CXR for collapse/consolidation
ICU admission: do well for 12-24 hrs
No routine antibiotics/steroids
When should you not do a RSI?
High risk for airway loss:
* Facial and airway trauma
* Patients in imminent danger
of losing their airway
* Patients unable to open
their mouth
* Jaw / tongue / large neck
abscesses
* Fixed neck deformities
* Base of Tongue / pharynx
tumours
What should be done if RSI cannot be done?
Awake fibre optic intubation
Front of neck access/awake tracheostomy
What must you do if you have a failed intubation?
Have a contingency plan including:
- knowing where difficult airway equipment is
- senior colleague
What must be the contingency plan for haemodynamic instability of rapid induction
relative overdose of anesthetics (hypotension)
Insufficient induction (hpt, tachycardia, dysrytthmia)
How do you prepare for RSI?
Routine machine and equipment check
Skilled assistant for cricoid pressure
Tilting bed / table / trolley
Patient supine in sniffing position
Suction at arms length and switched on
Patient monitoring attached with baseline readings
Plan for failed intubation
What is the technique of RSI?
- Pre-oxygenate: 80-100%, tight fitting mask, O2 flow rate >4L/min
- Before injection: IV working, opiod given before induction(fentanyl, alfentanil->dampening intubation response)
- Induction agent: predetermined dose, ANY IV induction agent is suitable depending on scenario, Etomidate/ketamine for hypotensive/shocked
- Relaxant: Suxamethonium or if contraindicated, Rocuronium 0.9-1mg/kg
