General Anaesthesia: IPPV with ETT Flashcards
Rank the Muscle Relaxants from shortest duration of action to longest duration of action and include their onset time
Muscle Relaxant
Onset time (min)
Duration (min)
Suxamethonium
<1
5-10
Mivacurium
2-3
10-20
Atracurium
2-3
20-30
Vecuronium
2-3
20-30
Rocuronium
1-2
30-40
Pancuronium
3-5
40-60
What can be done just prior to giving muscle relaxant
A quick check to see if BVM is possible
What can be while awaiting the effect of the muscle relaxant?
Assist ventilation with BVM (with Guedel). 100% O2 with about 1.5 MAC of the volatile agent should be administered. - ensures that when IV induction agent wears of, the inhalational agent maintains the unconsciousness
Give three possible causes for a sudden increase in Pmax (airway pressure) during volume control
- Increase resistance
- Decrease compliance
(Most commonly from inadequate MR) - Problem with circuit or ETT
(During P control ventilation: tidal volume needs to be observed for changes instead
Describe the steps taken once surgery is complete
- 100% O2. Other gases off
- Adjust RR to allow CO2 to rise for SV
- Nerve stimulator to assess reversibility
- If appropriate give Neostigmine with atropine/glycopyrrolate
- Insert Geudel airway prior to extubation (biting and BVM)
- SV observed on capnograph and clinical effort –> turn off ventilator and assess
- Patient should be sufficiently awake: coughing/attempts at removing ETT/eye opening/responding to commands BEFORE the ETT is removed.
- Ongoing suction.
- Remove ETT
- Check airway and SV
- Hudson Mask O2 at 4-5L/min and ensure misting of mask.
- Detach monitors and transfer to recovery
What makes up the upper and lower oesophageal sphincters
Upper: Cricopharyngeus muscle
Lower: Lowest 2 - 4 cm of the oesophagus
Describe the ASA fasting guidelines
Ingested material Minimum fast (h)
Clear liquids
2
Breast milk
4
Infant formula milk
6
Non human milk
6
Light meal
6
What patient factors increased risk of regurgitation and aspiration
Delay gastric emptying
- Trauma, pain, opioids, DM
Raised intra-abdominal pressure
- Obesity
Oesophageal sphincter incompetence
Interference with oesophageal emptying
How does RSI differ from non-RSI
In non-RSI: After co-induction the MR is administered and then there is a delay of 2 - 3 minutes before optimal intubation conditions are achieved. BVM must occur during this time to maintain oxygenation.
This is unsafe in patients at risk of regurgitation and aspiration because:
- Airway unprotected for 2-3 minutes
- BVM insufflates the stomach, increasing intra-gastric pressure –> increase likelihood of regurgitation
List the essential components of RSI
- PreO2
- Administration of predetermined dose of induction agents followed immediately by Suxamethonium
- Apply cricoid pressure
- Avoidance of BVM after MR
- Place ETT and inflate cuff
- Confirm placement
How much force should be applied during cricoid pressure and when should cricoid pressure be abandoned
10 N while patient awake (1 kg) (I L of water)
30 N after loss of consciousness (3kg)
If placement of SGD or ETT is difficult Active vomiting (avoid oesophageal rupture)
How can adequate preoxygenation be confirmed?
By checking the ET O2 on the monitor - Target = 85% ET O2
At what level is the cricoid cartilage
C6
What is the technique for cricoid pressure in a patient with C-spine injury
Place free hand behind the neck to prevent posterior displacement during cricoid pressure. Manual inline immobilization must be done simultaneously.
What dose of SUX is used for RSI
1.5 mg/kg
