Delayed Sequence IntubationRosie Stroud

A bit of a discussion…You see a 50 year old male with bad bilateral

pneumonia. BP 108/70, HR 96, RR 28. He is delirious, agitated, and looks sick, sick, sick! Sats are 70% on nasal cannula; when you try to

place the patient on a non-rebreather mask he just swats your hand away and rips off the mask.

What are you going to do……..? RSI??

RSI is a bad idea Your first impulse may be to perform RSI, maybe with some

bagging during the paralysis period. This is essentially a gamble. If you have first pass success, you (and your patient) may just

luck out, allowing you to get the tube in and start ventilation before critical desaturation and the resultant hemodynamic instability.

However, the odds are against you:1) bagging during RSI predisposes to aspiration2) conventional BVM without a PEEP valve is unlikely to raise the

saturation 3) If there is any difficulty in first-pass tube placement your patient

will be in a very bad place.

RSI vs. Delayed Sequence Intubation

Standard RSI = simultaneous administration of a sedative and a paralytic agent + no ventilations until after endotracheal intubation

This sequence can be broken to allow for adequate pre-oxygenation without risking gastric distention or aspiration

RSI vs. Delayed Sequence Intubation

Delayed sequence intubation = specific sedative agents, which do not blunt spontaneous ventilations or airway reflexes + a period of pre-oxygenation before the a paralytic agent

It’s a bit like a procedural sedation, the procedure in this case being effective pre-oxygenation. After the completion of this procedure, the patient can be paralyzed and intubated. Just like in a procedural sedation, we want our patients to be calm, but still spontaneously breathing and protecting their airway.

What is the evidence for pre-oxygenation?

The lungs absorb approx 250ml 02 / minuteIn room air we have 450ml 02 in our lungs: a 1-

1.5L total body resevoirWith good pre-oxygenation we get 3000ml 02 in

the lungs; a total of 3.5-4L total reservoir

This means more time until destauration

Weingart study - 2014 Does the use of ‘delayed sequence intubation’ improve pre-intubation oxygen

saturations ? Prospective observational case series, non-randomised and non-blinded 3 hospitals in USA/Denmark, Level 1 trauma centre or quarternary referral

centre, Study period: May 2011 to December 2013 Outcomes Difference in SpO2 after pre-oxygenation with:

a) standard attempts b) ketamine (just prior to administration of muscle relaxation)

significant increase post ketamine 88.9% vs 98.8% (increase of 8.9%, 95% C.I. 6.4-10.9)

Secondary outcomes: Subgroup analysis

SpO2 after pre-oxygenation with ketamine in patients with initial SpO2 ≤93% after pre-oxygenation with standard attempts 

all increased SpO2 to >93%

Nasal prongs2L/min = 24%4L/min = 27%15L/min = 44%Put on at the beginningConsider use during pre-oxygenation (4-15L)Give 15l/min when drugs have been given

Normal lungs, ventilating OK, airway OK

Correct positionNasal prongs on at 4-15L/minNRBM at 15L/min3 minutes of pre oxygenationOn induction increase nasal

prongs to 15L /min

Normal lungs, ventilating OK, reduced GCS - obstructing

Correct positionNasopharyngeal /oropharyngealChin lift/jaw thrustNasal prongs at 15L/minNRBM at 15L/min3 minutes

Abnormal lungs, hypoxia, airway OK

Need to use CPAP/PEEP Trying to recruit alveoliShunt situationTherefore need maximal positive pressureUse CPAP at 5-15 cm H2O with nasal prongs in

place3 minutes, induce and increase NP to 15L/minLeave CPAP in place until ready to intubate

CONTRA-INDICATIONS?Cardiac and respiratory arrestSpinal traumaSevere facial traumaSevere head injury

You see a 50 year old male with bad bilateral pneumonia.

BP 108/70, HR 96, RR 28. He is delirious, agitated, and looks sick, sick,

sick! Sats are 70% on nasal cannula; when you try to

place the patient on a non-rebreather mask he just swats your hand away and rips off the mask.

What are you going to do……..?