Today, I’m going to make some notes on case 2 of Dr. Horezcko’s podcast.
Dr. Horeczko’s site is the Pediatric Playbook. In his outstanding podcast and show notes, [Pediatric] Adventures In RSI Nov 2015, Dr. Horeczko discusses RSI in four different cases: sepsis, multitrama, cardiogenic shock, and status epilepticus. I did a summary post, Pediatric Rapid Sequence Intubation – Awesome Podcast From Dr. Horeczko October 30, 2016.
Case 2 runs from 22:30 to 29:10 and is a case of multiple trauma in a 3 year old boy. Dr. Horeczko discusses the considerations on what induction agent and what paralytic agent we should use in this trauma patient:
We need to adjust our dosing for a critically ill patient: Decrease the sedative to avoid falling over the hemodynamic compensation cliff. Increase the paralytic to account for prolonged arm-brain time.
Here is the second case:
Joseph is a three-year-old boy who is so excited because there are so many people at is house for a family party and when it’s starting to wind down and the guests are starting to leave, he is unaccounted for.
An unsuspecting driver of the minivan backs over him.
He is brought in by the paramedics who are now bagging him.
His primary survey shows that he is intermittently apneic but he has good chest rise with bag valve mask ventilation.
His breath sounds are clear bilaterally.
His abdomen is firm and echimotic.
And his extremities show deformities of his right femur and tibia and fibula.
On secondary survey, is GCS is eight.
His pupils are reactive.
Andy has a large scalp hematoma and laceration over his parietal area.
His heart rate is 140. Blood pressure is 90/40. Oxygen saturation is 98% on nonrebreather mask.
You get an IO in. [Intraosseous needle vascular access]
What sedative agent would you use for this patient’s RSI?
Well, we are looking for something that is hemodynamically stable. Agents like midazolam or propofol would cause too many problems.
Etomidate is a short acting [agent] that acts on GABA a receptors to induce loss of consciousness in 5 to 15 seconds. It can cause apnea, pain on injection, and most notably myoclonus (we’ve all seen this).
Etomidate reduces cerebral blood flow, reduces intracranial pressure, and reduces cerebral oxygen consumption. All while maintaining arterial blood pressure and cerebral perfusion pressure.
Smith et al performed a prospective observational study of RSI using etomidate in an urban level I Trauma Ctr. there were no reports of inadequate sedation or difficult intubation conditions. And there was no significant change in hemodynamic status after the ministration of etomidate even on patients with significant cardiac disease and pre-induction hypotension.
Ketamine is fine here, by the way, as reported by Dr. Steve Greene et al in Annals of Emergency Medicine in 2014.
There is no contraindication to ketamine except for known hydrocephalus. It is safe and head trauma. It is a good choice in the hypotensive trauma patient.
TBI [traumatic brain injury] is not a contraindication (to ketamine).
In the case of the critically injured child who is normotensive ketamine will raise his blood pressure and perhaps foster further bleeding.
The goal is good general perfusion and a balanced resuscitation, ensuring good cerebral perfusion without disrupting nascent clots.
On the other side of the spectrum, permissive hypotension as a protective mechanism that we employ in adults – it’s just not described in children as hypotension is a late and dangerous sign of shock.
All right, what about our paralytic of choice?
Are your surgeons in an uproar about a long-acting agent and the pupillary response?
By the way, it’s a myth.
Caro et al. in Annals of Emergency Medicine in 2011 reported that the majority of patients undergoing RSI preserved their pupillary response. Succinylcholine actually performed slightly worse than rocuronium. In the rocuronium group, all patients preserved their pupillary response.
Anyway, let’s say that it is your agreement with the surgeons is that you will use succinylcholine here. In this case there are no contraindications and the child is otherwise healthy.
You repeat the vital signs as you pre-oxygenate and prepare to induce.
His vital signs have changed. His heart rate is 160 and his blood pressure is 78. You are concerned that he is worsening.
You give blood to resuscitate before you intubate. And you rethink your paralytic and your sedative.
In a critically ill child or adult, perfusion suffers and it affects how we administer the medications.
The patient’s arm to brain time or the vein to brain time is less efficient.
Additionally, as the patient’s hemodynamic status softens he becomes very sensitive to the effects of sedatives.
We need to adjust our dosing for a critically ill patient.
We will decrease the sedative to avoid falling over the hemodynamic compensation cliff and we will increase the dose of paralytic to account for prolonged arm brain time.
Even in a hemodynamically stable drug like etomidate it can still show small changes in blood pressure. In many patients even if hypertensive there is minimal effect. We can give etomidate in these hemodynamically unstable patients, exactly to avoid this problem.
But we can be smart about it. We can use prudence to adjust the dose of etomidate. Instead of the usual fall RSI dose of .3 mg per kilogram, we elect to give half that dose – typically the procedural sedation dose of 0.15 mg per kilogram up to .2 mg per kilogram.
Since the arm brain time is prolonged due to poor perfusion, we need to increase the paralytic. So use the full 2 mg per kilogram of succinylcholine, up to 3 mg per kilogram, to ensure that the onset is rapid and full.
You can use the generous dose of rocuronium at 1.2 mg per kilogram or up to 1.6 mg per kilogram in a patient with poor perfusion.
Blood running, the patient preoxygenated and properly positioned, you give rock uranium 1.6 mg per kilogram IV and etomidate 0.15 mg per kilogram.
You use a Miller 2 to lift up the Omega shaped epiglottis and gently pass a 4.5 cuffed ET tube in this three-year-old boy.
You verify clinically and with colorimetric [or better – wave form capnography].
You get the boy stabilized. He is then transported to the scanner which is going to help us guide further surgical, interventional radiologic, or supportive care.
At the end of the post Dr. Horeczko summaries his talk as follows:
In summary, in these cases of sepsis, multitrauma, cardiogenic shock, and status epilepticus:
- Resuscitate before you intubate
- Use the agent’s specific properties and talents to your benefit
- Adjust the dose in critically ill patients: decrease the sedative, increase the paralytic
- Have post-intubation care ready: analgesia, sedation, verification, NG/OG/foley
