Warming human milk in the NICU has always been a task that is time-consuming for the bedside nurse, and doing it properly – the right amount of time and temperature – has not been an easy task. Cup and water was the “gold standard” across most NICUs until commercial warmers came on the scene.
Anyone who’s been a NICU nurse for more than 10 years remembers some kind of plastic bucket hanging around every bedside to fill with water to warm, thaw, or defrost milk. The water was never a consistent temperature, as we took it from the tap or some hot water faucet, stuck a finger in and thought, “that’s good enough.” That bucket of tap water then went over to the neonate’s bedside, where we made room for our plastic bucket and stuck our syringe or container of milk into it.
Does anyone remember having a chart to tell us how long to keep our syringe in the water? To my knowledge and experience, none ever existed. So we just waited until it seemed like a good amount of time, dropped a few drops onto our wrists and thought, “that feels OK,” and began a feeding.
This method is not only time-consuming and inaccurate, it’s also not the safest for the baby. First, much of that water in the NICU is coming from a hospital system that has, in many cases, shown potential to be a breeding ground for bacteria. Hospital pipes grow a layer of biofilm over the years, and within that biofilm is where bacteria such as cryptosporidium, Giardia, E. Coli, klebsiella, and pseudomonas can grow and thrive. Biofilm is a slimy layer of film. One example I like to give about biofilm is something many pet owners will understand. If you have pets and a water bowl, you might notice that after a few days the sides and bottom of the bowl develop a slimy layer when the bowl is wiped down. That disgusting slime is what can be found in hospital pipes, and I’m sure nurses would agree that is not something we need to be exposing our NICU patients to.
Warming human milk in water is also inconsistent. We have no way of knowing what the temperature of the warmed milk really is. Body temperature milk is best – just like what is gotten from mom’s breast – but how do we know that exactly? Also, a few drops on the wrist might feel warm to me, but hot to someone else. Studies show that perceptions of temperature vary from person to person.
So what is an answer to all these issues? One really easy fix is to use a waterless, hospital-grade warmer. Medela offers two choices:
1. The Waterless Milk Warmer that works by circulating warm air onto a container (such as a syringe or bottle). This has been tested and timed to heat, thaw, or defrost to a temperature consistent with expressed human milk.
2. An in-line enteral warmer – the Guardian Warmer – for warming enteral feeds given on a pump. This device basically works like a blood warmer: the enteral extension set coils into a small device and warms the milk as it flows through the tubing.
These devices address the need to get water out of the NICU milk warming process AND provide consistent warming to near or at body temperature. For the bedside nurse it also means less time dealing with additional tasks such as working with plastic buckets, filling them with water and letting containers sit (sometimes too long) on the top of an isolette.
A commercial warming device has become the new “gold standard,” and moving away from the old cup and water is something every NICU needs to do. Moving in this direction is a step for a safer milk delivery practice, and it also improves nursing efficiency and time: two things nurses everywhere will always welcome.