Breast milk has many benefits and seems to be in the health care news feeds almost daily. As the evidence mounts for long term effects of the infant microbiome, more and more centres are insisting on providing human milk to their smallest infants. Such provision significantly reduces the incidence of NEC, mortality and length of stay. There is a trade-off though in that donor milk after processing loses some of it’s benefits in terms of nutritional density. One such study demonstrated nutritional insufficiencies with 79% having a fat content < 4 g/dL, 56% having protein content< 1.5 g/dL, and 67% having an energy density < 67 kcal/dL (< 20 Kcal/oz). It is for this reason that at least in our unit many infants on donor milk ultimately receive a combination of high fluid volumes, added beneprotein or cow’s milk powders to achieve adequate caloric intake. Without such additions, growth failure ensues. Such growth failure is not without consequence and will be the topic of a future post. One significant concern however is that failure of our VLBW infants to grow will no doubt impact the timing of discharge as at least in our unit, babies less than 1700g are unlikely to be discharged. With the seemingly endless stream of babies banging on the doors of the NICU to occupy a bed, any practice that leads to increasing lengths of stay will no doubt slow discharge and cause a swelling daily patient census.
What if increasing volume was not an option?
Such might be the case with a baby diagnosed with BPD. Medical teams are often reluctant to increase volumes in these patients due to concerns of water retention increasing respiratory support and severity of the condition. While diuretics have not been shown to be of long term benefit to BPD they continue to be used at times perhaps due to old habits or anecdotal experiences by team members of a baby who seemed to benefit. Such use though is not without it’s complications as the need to monitor electrolytes means more needle sticks for these infants subjecting them to painful procedures that they truly don’t need. Alternatively, another approach is to restrict fluids but this may lead to hunger or create little room to add enough nutrition again potentially compromising the long term health of such infants.
Amy Hair and colleagues recently published the following study which takes a different approach to the problem Premature Infants 750–1,250 g Birth Weight Supplemented with a Novel Human Milk-Derived Cream Are Discharged Sooner
This paper is essentially a study within a study. Infants taking part in an RCT of Prolacta cream (Prolacta being the subject of a previous post) were randomized as well to a cream supplement vs no cream. The cream had a caloric density of 2.5 Kcal/mL and was added to donor milk or mother’s own milk when the measured caloric density was less than 19 Kcal/oz. The study was small (75 patients; control 37, cream 38) which should be stated upfront and as it was a secondary analysis of the parent study was not powered to detect a difference in length of stay but that was what was reported here. The results for the groups overall were demonstrated an impact in length of stay and discharge with the results shown below.
|Control (N=37)||Cream (N=38)||p|
|PDA ligation %||8.1||2.6||0.36|
|PDA treated medically %||27||29||0.85|
|Length of stay, days||86+/-39||74+/-22||0.05|
|PMA at discharge, weeks||39.9+/-4.8||38.2+/-2.7||0.03|
What about those with sensitivity to fluid?
Before we go into that let me state clearly that this group comparison is REALLY SMALL (control with BPD=12 vs cream with BPD=9). The results though are interesting.
|BPD control (N=12)||BPD cream N=9||p|
|Length of stay, days||121 +/-49||104+/-23||0.08|
|PMA at discharge, weeks||44.2+/-6.1||41.3+/-2.7||0.08|
So they did not reach statistical significance yet one can’t help but wonder what would have happened if the study had been larger or better yet the study was a prospective RCT examining the use of cream as a main outcome. That of course is what no doubt will come with time. I can’t help but think though that the results have biologic plausibility. Providing better nutrition should lead to better growth, enhanced tissue repair and with it earlier readiness for discharge.
One interesting point here is that the method that was used to calculate the caloric density of milk was found to overestimate the density by an average of 1.2 Kcal/oz when the method was compared to a gold standard. Given that fortification with cream was only to be used if the caloric density of the milk fell below 19 Kcal/oz where average milk caloric density is 20 Kcal/oz there is the distinct possibility that the eligible infants for cream were underestimated. Could some of the BPD be attributable to infants being significantly undernourished in the control group as they actually were receiving <19 Kcal/oz but not fortified? Could the added fortification have led to faster recovery from BPD?
Interesting question’s in need of answers. I look forward to seeing where this goes. I suspect that donor milk is not enough, adding a little cream may be needed for some infants especially those who have trouble tolerating cow’s milk fortification.