BVM Hack for Children and Infants
One of the most common questions we are asked is “What should be in our First Aid Kit or Medic Bags?”
The contents of either should be based on:
Your level of training - you should not be carrying anything you are neither trained, qualified, licensed or competent with.
Your Needs assessment - you should be carrying what you can reasonably predict to need.
In our operational bags we carry the Pocket BVM because it is so blissfully small, along with a selection of masks. We don’t carry Child or Infant BVMs as a standard because as a company we tend not to work with children or infants.
In our training bags we use the Adult size Ambu Spur II - despite it being designed for single use it is robust enough to stand up to training purposes. We don’t use Child or Infant BVMs in our training bags because neither Child or Infant BVM technique is on the syllabae for common Level 3 pre-hospital care qualifications such as First Responder, FPOS or FREC.
Adult, Child and Infant Sizes
What you can see from the table below is that the majority of manufactures make BVMs in increasingly smaller sizes to compensate for casualty’s increasingly smaller lung capacity.
From the table you can see that:
There is no definite standard. Each variant is similar in absolute volume and tidal volume but not the identical. They are within similar parameters.
The tidal volume quoted (the amount of air that is moved during each ventilation) will vary hugely depending on (1, 2) :
The size of the operators hands
Whether one or two hands are used
How aggressively the operator squeezes the BVM
When you have no Child or Infant BVM
If you are competent in BVM technique for children and infants, need to provide ventilatory support but do not have a Child or Infant BVM, and if you have a selection of masks and a catheter mount, it is possible to improvise.
If you compress the rear end of the BVM you will have reduced the absolute volume and the tidal volume to that of a Child BVM. (You will still require a child sized mask).
If you compress the front end as well, you will have reduced the absolute and tidal volume further to that of an infant BVM. (You will also require an infant mask and catheter mount).
The Ambu Spur II compressed down is still a little generous but not wildly outside of parameters. Just bare this in mind.
The Pocket BVM reduces down to the same specifications as the dedicated Ambu Spur II Child and Infant Sizes.
Is it perfect?
No, it is an improvisation for when you have the skills and not the equipment and necessity dictates. It is not a suitable alternative for not carrying dedicated equipment that has been identified in your Needs Assessment.
Is it reasonable?
Absolutely. The dangers of over-ventilating any patient is arguably more dangerous than under-ventilating the patient and certainly more common than under-ventilating, even with dedicated sized BVMs (2). Reducing the size of the BVM will deliver proportionally adjusted volumes and remember, the volumes of even dedicated Child and Infant BVMs will be dependent on other factors.
Hess D, Spahr C. (1990) “An evaluation of volumes delivered by selected adult disposable resuscitators: the effects of hand size, number of hands used, and use of disposable medical gloves.” Respiratory Care. 35(8):800-5.
Kroll M, Das J and Siegler J. (2019) “Can Altering Grip Technique and Bag Size Optimize Volume Delivered with Bag-Valve-Mask by Emergency Medical Service Providers?” Prehospital Emergency Care. 23:2, 210-214
Khoury A, Sall FS, De Luca A, et al. ( 2016) “Evaluation of Bag-Valve-Mask Ventilation in Manikin Studies: What Are the Current Limitations?”. Biomed Res Int. 2016: 4521767