Because we are not physicians where we are grilled on a daily basis for four years plus some, we find some procedures and medical decision-making difficult. This makes sense. We are expected to go out into the world and snatch people from the clutches of death with only a survey course in emergency medicine. However, our education and experience is what we make of it. Despite the lack of a decade of formal training to master difficult procedures, such as the mechanical ventilator, it does not mean we cannot conquer this beast. Let’s discuss this now.
The “Fire and Forget” Phenomenon
One of the biggest pitfalls that we experience in using the mechanical ventilator is something I like to call the “fire and forget” phenomenon. If you have ever set up a patient on a ventilator and applied the standard-setting of 12 respirations per minute and 500 tidal volume and never made any vent changes, then you could have fallen victim to the fire and forget phenomenon. If you are a critical care provider, then it is expected that you use a mechanical ventilator. This of course means you bring the ventilator to the patient’s bedside every single intubated patient. That being said, critical care providers routinely and consistently reassess the patient, which means adjusting the ventilator based on the patient’s current vital signs, and the ventilator feedback.
Consider this question to hammer home my point: have you ever given a patient morphine? Of course you have. What about nitroglycerin? Will yes, of course you have given it too. After you gave these medications, what is the one thing you most likely checked? Yes, it is blood pressure. Now, would you ever administered these medications without checking a blood pressure? No, of course you wouldn’t because standard practice dictates that after you give a medicine that can reduce blood pressure you reassess the patient’s vital signs. This is the same with the mechanical ventilator.
The mechanical ventilator is a machine, obviously. You apply settings to the machine and the machine delivers those settings. However, because we haven’t perfected the science of cyborgology, then quite often the settings you choose do not translate directly to the patient. This is why often you’ll have alarms going off of the ventilator. It is our job to check the feedback, or metrics, that the ventilator gives us. We set a rate, but we must check frequency (f) to ensure that the patient is not breathing faster than the rate we set. If they are, then additional sedation or pain medication is most likely needed. We set a tidal volume, but we must check the exhaled tidal volume (Vte) to ensure that it is close to our tidal ventilation setting. If you’re exhaled tidal volume (the amount of air that actually comes out of the patient) is lower than your set tidal volume, then you most likely have a dead space issue. If you your patient’s carbon dioxide levels are high or low, then you can look to see what your minute ventilation is (respiratory rate times tidal volume). If you have a high-pressure alarm, than you should check your peak inspiratory pressure (PIP). If you have a high PIP didn’t use your DOPE pneumonic to rule out reasons, and if you cannot find one, then you need to take a plateau pressure. A high plateau pressure indicates bronchoconstriction– administer albuterol or suction the patients trachea. If you have both a high PIP and plateau pressure, then most likely you have and injured or very poorly compliant lung.
Embrace the Education that Goes into Being an Expert
In the end, we obviously are not physicians. That has nothing to do with the fact that we cannot become experts in a procedure that is within our scope. Don’t be afraid of these procedures, but rather embrace the education that goes into being an expert. Don’t just “fire and forget”. Desire to perfect your craft and practice. With this attitude and mindset, we will be able to achieve fantastic professional accomplishments.