TBI Algorithm - Airway Management

What prompt will be given to you for this skill check?

“manage this deteriorating (E2/V3/M4) GCS 9 patient with a depressed skull fracture who rolled their vehicle which, now has a spiderweb pattern windshield break where they were sitting”

What is the first portion of the TBI algorithm?

ASAP (assess, suction, adjuncts, positioning)

What is the first step in the ASAP portion of the TBI algorithm?

assess → open the mouth, nares, and neck with a jaw thrust to visualize for obstruction, contamination, or deformity (blood, vomit, swelling, etc.)

What is the second step in the ASAP portion of the TBI algorithm?

suction → suction as needed, or place suction unit near the patients head in preparation for its need

What is the third step in the ASAP portion of the TBI algorithm?

adjuncts → OPA if GCS ~8 (with absent gag reflex)

note: NPA’s are a last ditch effort when there are skull fractures involved due to the cribriform plate of the ethmoid bone

How is the adjuncts step in the ASAP portion of the TBI algorithm completed?

• size an OPA from top of the teeth to the angle of the jaw

• insert the OPA to optimize patency (intially by the curve against the hard palate with a final rotation)

What is the fourth step in the ASAP portion of the TBI algorithm?

positioning → secure patient’s head in neutral in-line position manually or with c-collar (likely meets SMR if this is being used) + elevate head 30° on stretcher (semi-Fowler’s positioning)

What should be considered during the positioning step if ventilations cannot be obtained with neutral positioning, jaw thrust, and adjuncts?

consider gentle head elevation approaching ear to sternal notch face parallel to ceiling

What are signs that highly indicate the presence of a moderate to severe TBI?

• increasing confusion

• GCS <12

• seizures

• ineffective breathing (RR<10)

• hypoxia

What should be done if the patient is suspected to have a moderate to severe TBI, but they are effectively ventilating?

prevent hypoxia

What should be done if the patient is suspected to have a moderate to severe TBI, but they are not effectively ventilating?

prevent hyperventilation

What are signs that indicate cerebral herniation?

• GCS <9 with any of the following present:

  • dilated and unreactive pupils

  • asymmetric pupillary response

  • decorticate or decerebrate posturing

What is hyperventilation?

• rapid decline in arterial CO₂

  • kicks body into “fight or flight”

  • smooth muscles contract → decreased cerebral and coronary blood flow

  • triggers release of stored CO₂ from body cells → intracellular alkalosis

• rise in pH of the blood results in acid-base balance becoming more alkaline → respiratory alkalosis

• intracellular alkalosis causes the kidneys to increase the excretion of bicarbonate (acid neutralizer) → extracellular alkalinity

What is respiratory acidosis?

when the lungs cannot remove enough CO₂ (or the body is overproducing CO₂) → decrease in blood pH (becomes more acidic)

What is respiratory alkalosis?

blood pH rises above 7.45 (becomes more basic) due to excessive breathing (hyperventilation) → decrease in CO₂ levels in the blood

What is metabolic acidosis?

• too much acid in the body fluids

• often associated with untreated diabetes/kidney conditions

• caused in the body by:

  • body produces too much acid

  • kidney’s can’t remove enough acid

  • body loses too much bicarbonate

What is metabolic alkalosis?

• body fluids have become too alkaline (basic)

• caused in the body by:

  • body produces too much bicarbonate

  • lungs expel CO₂ much faster than it can be replaced due to breathing too fast/deep

  • body loses too much acid

How can hypoxia be prevented?

• place nasual canula ETCO₂ to monitor RR continuously

• place NRB 10-15 Lmin over top the NC ETCO₂

• cycle BP every 2 minutes

How can hyperventilation be prevented?

• connect tubing to reservoir port

• run oxygen at 10-15 L/min

• attach ETCO₂, filter, and correctly sized mask

• ensure monitor is displaying ETCO₂ waveform

• target of 10/min (or 1 breath every 6 seconds)

• utilize the ETCO₂ RR reading as a biometric feedback guide (and a metronome if available)

  • this is NOT optional

• squeeze bag only enough to achieve chest rise

• continuously monitor

  • loss of patency (be ready to suction)

  • manual BVM ventilations for appropriate rate and depth

  • SpO₂ for hypoxia (troubleshoot the airway)

What are the H-bombs?

• hypoxia

• hyperventilation

• hypotension

• hypoglycemia*

*important to check as it may mimic a TBI or be the cause of an accident

What is meant by “management of ventilation”?

special emphasis is placed on identifying and treating hypoventilation (as well as preventing hyperventilation when assisting ventilation)

Why is hyperventilation so dangerous?

it kills neurons

What is inadvertent hyperventilation?

no one can properly ventilate without ventilatory adjuncts:

• ventilators

• ventilation rate timers

• ETCO₂ monitoring

• cadence devices

• resistance-controlled BVMs

therefore = no manual or unassisted BVMs without some kind of metronome (there is NO room for error in these situations)

What are the calculated additive dangers of the H-bombs for moderate to severe TBI patients?

hypoxia = 5 times worse

hypotension = 3 times worse

hypoxia + hypotension = 17 times worse

What is main takeaway regarding severe TBI patients and the H-bombs?

your severe TBI patients need to have any hypoxia and hypotension corrected while maintaining normocarbia (ETCO₂ of 35-45 mmHg)  → therefore, know the signs of moderate to severe TBI well

When should a patient be purposefully (and mildly) hyperventilated?

• only when hypotension and hypoxia have been corrected, but your patient continues to present with or develop the indicated signs of cerebral herniation (the brain squeezing through the foramen magnum)

• this is a “kitchen sink” strategy with only theoretical benefit in the most critically ill TBI patients

  • if attempted in moderate to severe patients it has demonstrated harm

When are ETCO₂ levels considered inaccurate (and how can accuracy be improved)?

• when using a face mask and BVM

• accuracy might be improved by:

  • using a two-hand grip

  • IGEL supraglottic airway

Why do patients with hypotension have “lower than actual” ETCO₂ readings?

• lungs are becoming less perfused with blood, meaning less CO₂ is able to be dumped with each breath

• arterial blood is actually becoming hypercapnic (high CO₂) due to poor transport, but the exhaled breath indicates hypocapnia (low CO₂) due to reduced volume of blood in the lungs

  • in other words, the end-tidal monitor cannot account for alveolar dead space created by hypotensive conditions

What is alveolar dead space?

the volume of alveoli that are ventilated with air but are not adequately perfused with blood