Intubation in the ER ‘Chapter 2’ LMHER Rounds May 31, 2017 Prepared by Shane Barclay MD

Overview Which paralytic to use for intubation. The timing and sequence of RSI medications for intubation. Rapid Sequence Intubation versus Delayed Sequence Intubation.

Historical Perspective Historically rural doctors have done a variety of things for patients that needed respiratory support – ie intubation. Bag and wait for the medivac. Intubate using drugs and techniques that are probably now out of date. Using the same drugs and techniques that are used by full time urban emergency physicians today.

Two types of drugs Induction drugs – Midazolam, Propofol, Ketamine. Paralytics (Neuromuscular Blockage Agents – NBA) – Succinylcholine, Rocuronium.

Paralytics - NBA Succinylcholine. - Onset 5 – 10 seconds. - Duration of action 8 -15 minutes. Rocuronium. - Onset 30 seconds. (using 0.5 mg/kg) - Duration of action 45 – 60 minutes.

A great 8 minute talk by Dr A great 8 minute talk by Dr. Reuben Strayer on Succinylcholine versus Rocuronium

Timing and Sequence of RSI medications

Timing of medications Historically the order and timing of RSI meds has been: - pre RSI meds (Fentanyl, lidocaine, atropine etc.) - Induction medication (Midazolam, Propofol, Ketamine etc) - Paralytic (Succinylcholine, Rocuronium) The timing between induction and paralytic has been debated.

Timing of medications “Timing Principle” This is an anesthetic term that involves giving a bolus of nondepolarizing muscle relaxant, followed by an induction drug at the ‘onset of weakness’ (ie ptosis)

Timing of medications “Timing Principle” The rationale behind it is that induction agents cause apnea. If you cause apnea and then give a paralytic and have to wait for its onset of action, the patient will be in a longer state of apnea with its concomitant potential risks.

Timing of medications “Timing Principle” The other argument has been that if you are using Rocuronium it has a longer onset of action. Therefore by giving Roc and waiting for ‘weakness’ you can then give a quick acting induction agent thereby shortening the apneic period.

Timing of medications “Timing Principle” The timing principle has only recently entered the emergency medicine literature relative to the anesthetic literature. Although timing principle has not been widely adopted, the more general consensus has been to give induction agent with paralytic at the same time, followed by a saline flush.

Timing of medications However, Midazolam and Propofol cause apnea, but Ketamine does not. Second, if Rocuronium is given at the 0.6 mg/kg dose it does have a long time of onset. However if given at 1.2 mg/kg its onset is the same as Sux. So one option is to give Ketamine and Rocuronium (at 1.2 mg/kg) at the same time or one right after the other, followed by a saline flush. This seems to minimize the time of any apnea in the patient.

RSI versus DSI

Definitions Rapid sequence intubation (RSI) is an airway management technique that produces immediate unresponsiveness using induction agents and muscular relaxation (neuromuscular blocking agent) Delayed sequence intubation is a technique for patients requiring emergent airway management, but who are resistant to pre- intubation preparations because of altered mental status.

Remember this? Rapid Sequence Intubation Checklist 1. Oxygen. Pre-oxygenate with NRB/+/- OPA or OPA/BVM or LMA/BVM at 15 lpm x 4 minutes 2. Positioning – sniffing position, ideally head up 30 degrees 3. Decide on RSI meds below (16, 17, 18) – ask RN to draw up. ……

Pre-oxygenation Pre-oxygenation is not a theoretical construct. The 2 things that increase mortality and morbidity in intubations are hypotension and hypoxia. No intubation should be attempted until Oxygen saturations are at least up over 95% (ideally 100%) for several minutes. This requires all the skills under ‘supraglottic airway management’, including head position, OPAs, NRB mask, addition of nasal prongs, proper 2 handed BVM …

Pre-oxygenation The idea behind pre-oxygenation is to get the patient as close to 100% oxygen saturation as possible BEFORE intubation attempt. This will usually take a minimum of 3 - 4 minutes. If you are providing BVM, it must be done correctly.

Pre-oxygenation

Pre-oxygenation You want to be as high up and to the right on that dissociation curve as you can possibly be!

Pre-oxygenation So if the patient is fighting you and you can’t adequately oxygenate them, you want to do a ‘Delayed Sequence Intubation’. You don’t start intubation just when you have all your equipment and check lists done – you also need the patient to be oxygenated! This can involve partially sedating the patient so you can adequately oxygenate them.

Delayed Sequence Intubation DSI is basically procedural sedation, followed by a paralytic and intubation! The ‘procedure’ in this case is ‘oxygenation’.

Delayed Sequence Intubation Pt. requires intubation but resistant to pre-intubation preparation due to altered mental status. Dissociation. Give Ketamine 0.5 – 1 mg/kg slow IV push. Repeat q 10 – 15 seconds until patient is ‘dissociated’. Preoxygenate with Non-rebreather plus nasal cannula. If sats < 95% switch to NIV CPAP. Denitrogenate for 3 minutes. Once dissociated, you can also position Pt, add IVs, etc. May add some more ketamine, then paralyze as usual. Intubate (with nasal cannula still on at 15 lpm)

Delayed Sequence Intubation Why Ketamine? As mentioned previously, Midazolam and Propofol cause apnea. Unless you rapidly bolus a large dose, patients will not become apneic with Ketamine.

Summary Rocuronium is probably a safer and better paralytic in most intubation scenarios. For RSI, don’t give an induction agent then wait for the patient to become apneic before giving the paralytic. Give the paralytic and induction agent at the same time followed by a saline flush. Pre-oxygenation is crucial for best patient outcomes. If the patient is uncooperative/combative, use delayed sequence intubation with ketamine to allow you to properly oxygenate the patient.

Thank you.