Premedication for intubation Flashcards
What are the adverse effects of incubation?
5
- Pain
- Systemic and pulmonary HTN (increased SVR from pain-induced catecholamine release)
- Bradycardia (independent of hypoxia)
- Intracranial HTN (secondary to coughing and struggling)
- Hypoxia (independent of bradycardia)
Why are the broad categories of our interventions and what physiological response do they target?
- Vagolytics - vagal tone+ bradycardia
- Muscle relaxation - Intracranial HTN
- Analgesia - systemic HTN. Also reduces endorphins and endocrine response (Catecholamines)
- Pre oxygenation - hypoxia
- Gentle technique
Apart from decreasing intracranial HTN, what is another benefit of muscle relaxation?
More likely to be successful, therefore fewer attempt and less hypoxia
What opiate should you use for analgesia and why?
Fentanyl - short onset of action
NB morphine does not appear to reduce the occurrence of hypoxia with bradycardia likely because of its slow onset of action (>10 minutes)
Remifentanyl and meperidine are good options, but there is limited information available on the pharmacokinetics and pharmacodynamics in neonates.
Apart from opiates, are there any other options for analgesia?
Thiopental, a barbiturate anaesthetic, has been studied and showed good pain control. But is very difficult to eliminate from the body, so remains a concern. Methohexital is an alternative barbiturate, but there is no PK or PD information in neonates?
Other: Propofol, Midazolam
What is Methohexital and can we use it in intubation?
It is a barbiturate.
It is shorter acting than thiopental
Adult data shows that it helps with smooth intubation.
But there is no PK or PD data on it, so we cannot use it.
Can we use propofol?
Propofol is a hypnotic agent.
There is data showing that when used with morning, atropine and succ, intubation was faster with better O2 sats.
Because it is a hypnotic agent, you need to use it with analgesia.
Concerns regarding using it relate to variability in clearance and hypotension. So NO.
Can we use Midazolam?
NO
Sedative only. So it cannot be used without an analgesia.
It does not reduce the physiological changes of intubation. It has been associated with adverse effects: Hypotension, decreased cardiac output, decreased cerebral blood flow velocity.
Has variable kinetics, and long half life.
What are the complications of premedication?
None of the randomised controlled trials have demonstrated serious complications from premedication
Use of short acting opiates has been associated with increased muscle tone including tone in the chest wall. This can be avoided if given slowly and treated with muscle relaxant and/or opioid antagonist
If you are intubating to give surfactant, are the any special considerations?
Yes, you want something that causes minimal respiratory depression and/or sedation.
Although fentanyl has a half life of 10 hours in a newborn, it does not use respiratory depression and infants can safely be extubated within 1 hour.
ALTERNATIVE: remifentanyl - but limited data
Under what clinical circumstances is it ok to intubate an infant without the use of premedication?
If the risk of medication > risk of being intubated without medication
Examples:
- real resuscitation
- difficult airway - need to breath for themselves
Is lack of IV access a good reason to intubate without medication?
No, because there are alternate routes:
Nasal fentanyl
inhaled NO or sevoflurane
What are the characteristics of an acceptable protocol for premedication?
To include the following: vagolytic, analgesia, muscle relaxant
Which vagolytic is ideal?
Atropine and glycopyrolate are both effective, but the dosage for glycopyrolate in neonates has not been studied.
Atropine has not be associated with side effects when given at the correct dose 10-20 ug/kg
Which analgesia is recommended?
Want: amid onset with minimal effect on respiratory mechanics, short duration of action, good sedation, reliable kinetics.
Fentanyl is the closest to this. It does reduce respiratory drive. 3-5 ug/kg
