An issue came up with some time checking regarding three events (chemical paralysis, advanced airway placement, and qualifying GCS test) and when they happened relative to when the study kit was opened. This led to a discussion of placement of advanced airways, and what an “advanced” airway really meant.
When a patient is not able to breathe on their own, a medical intervention is used to pump air and/or oxygen to the lungs. This often requires the patient to be chemically paralyzed (to prevent the sputtering/choking response from having a tube shoved down your throat). For ‘definitive’ airways, this often involves having a tube with an inflatable cuff that goes past your vocal cords down into the space right above the lungs (care must be taken to prevent the tube from entering the stomach, which would be a ‘sentinel event’ — one that is likely to cause serious injury or death). A cuff is then inflated so that air can only flow in and out through the tube. This type of airway requires some form of imaging to ensure that the breathing tube gets to the correct spot (and doesn’t pierce the vocal cords or go into the stomach, for instance).
Another form of airway (which they dubbed ‘alternative’), involves the use of a breathing tube that does not go past the vocal cords (i think?). This type of airway cannot use a CO2 sensor (that turns purple from yellow) to indicate its correct placement.
The final airway is what she called a ‘Bag/Valve mask’, which is a mask placed over the patient where air/oxygen is pumped in. This may work for patients who are having trouble getting enough oxygen to their lungs but are still able to work the muscles to breathe — someone who is paralyzed (and/or has serious brain injuries) may not be able to breathe without intervention.
The real issue is that when a person is chemically paralyzed, taking an accurate assessment of their brain functioning (using the Glasgow coma scale, or GCS) is difficult to do. There are three components to the scale (E/V/M) – eyes, verbal, and motor, with max scores of 4/5/6. When a person is chemically paralyzed, their ability to respond to verbal commands (to move their extremities and eyes) is reduced, but it is unclear whether this was due to damage to the brain or simply to the drugs. A GCS score of <=12 is required for enrollment into the clinical study, so an accurate assessment of their GCS score is needed in order to determine eligibility status.
As an aside, if a person is intubated, their verbal score is 1 (since they can’t talk with a tube down their throat!).