Patient BVM Advocacy
- There have been several studies in the mid 2000’s regarding this topic and there are many agencies utilizing pediatric BVMs while still carrying adult bags as a backup.
- Pediatric BVM will deliver 400-500mL consistently. Keep in mind that normal physiology for an adult is 400-600mL.
- Each person has varying compliance due to physiology and pathophysiology.
- These studies showed that the average male can deliver up to 1200 mL at a time with 1 hand.
- Large tidal volume amounts delivered via BVM are due to things like physical size or capabilities (male/female), BVM brand/type, and providers emotions.
- Current practice utilizes a range of 6-8mL/kg for someone’s tidal volume and these numbers come from the ARDS net study and practice.
- A recent study showed experienced providers delivering 50 bpm accompanied by squeezing the bag too hard.
- If we squeeze too hard the subsequent increase pressure in the oropharynx opens the gastric sphincter and inserts air into the stomach inducing vomiting.
- Basic BVM use is paramount if applied correctly. EC or C3 method is inferior to 2 thumbs up method.
- Control the epi. YOUR EPI !!
Think about the last time you used a BVM for a call. Likely it was a full arrest, but maybe for a critically ill patient other than a code. As infrequently as we use a BVM or even have a call needing its use, when the call does come we tend to get a little anxious which throws off some of our treatments like respiratory rates. One of the best tools to help us recognize the appropriateness of our bagging rate is ETCO2. Having this number and knowing the correct range for our patient’s condition is an awesome addition to our bag of tools. It’s important to get this on the patient as soon as possible to help guide our treatment.
As we bag a patient with an adult BVM while having our own adrenaline dump, the result is a rapid respiratory rate with a high tidal volumes. According to the recent studies performed, we are ventilating these patients with around 700mL or more for each breath.
As a side note, if they are placed on a ventilator, we utilize a few formulas to figure out what is appropriate for each patient:
- Average tidal volume for patients is 6-8mL/kg.
- 90kg patient, you can expect a Vt of 540-720 per breath.
- For someone who is not intubated, we must maintain 60mL/kg/min for our bodies to have normocapnia. This means, the appropriate amount of CO in our body vs. oxygen which helps us feel normal. This would make the complete amount of Vt in a min at 5,400mL.
- When we intubate our patients this doubles due to dead space and size restriction making the norm now 120mL/kg/min. For this same patient of 90kg we would have our total Vt in one minute of 10,800mL.
- You then take this amount and divide it by the tidal volume (Vt), the outcome would then give you a respiratory rate 15-20bpm.
The tidal volumes listed above are for a person without lung affected pathology. Pt.’s who have problems with their lungs may only be able to tolerate ¾ of these tidal volumes. They have to be adjusted to higher respiratory rates and lower tidal volumes.
It is very difficult to change our personal physiologic response to stressful stimuli, but even those with experience can lose some control as seen in the 50bpm delivered during their study. Seattle‘s EMS system utilizes a technique with a pinky up method. This means while squeezing the BVM, they are to hold their pinky up on the same hand reminding them to be aware of the amount of “squeeze” they are delivering. Other agencies have chosen to require providers to squeeze from the bottom of the bag which engages different thought processes.
The information is not saying that we should change to all pediatric BVMs even though many agencies have; but perhaps we need to take the time to specifically train on effective BVM use. Practice methods to help control emotional factors and ventilating techniques to figure out which works best for you. Once again, by utilizing and watching our ETCO2 closely will help guide our respiratory rate for each patient.