Part 2: Does prophylactic dextrose gel really work?

Part 2: Does prophylactic dextrose gel really work?

In the first part of this series of posts called Can prophylactic dextrose gel prevent babies from becoming hypoglycemic? the results appeared to be a little lackluster.  The study that this blog post was based on was not perfect and the lack of a randomized design left the study open to criticism and an unbalancing of risks for hypoglycemia.  Given these faults it is no doubt that you likely didn’t run anywhere to suggest we should start using this right away as a protocol in your unit.

Another Study Though May Raise Some Eyebrows

New Zealand researchers who have been at the forefront of publications on the use of dextrose gel recently published another article on the topic Prophylactic Oral Dextrose Gel for Newborn Babies at Risk of Neonatal Hypoglycaemia: A Randomised Controlled Dose-Finding Trial (the Pre-hPOD Study).  As the short study name suggests “Pre-hPOD” this was a preliminary study to determine which dosing of dextrose gel would provide the greatest benefit to prevent neonatal hypoglycemia.  The study is a little complex in design in that there were eight groups (4 dextrose gel vs 4 placebo) with the following breakdown.

Dosing was given either once at 1 h of age (0.5 ml/kg or 1 ml/kg) or three more times (0.5 ml/kg) before feeds in the first 12 h, but not more frequently than every 3 h. Each dose of gel was followed by a breastfeed. The groups given prophylaxis fell into the following risk categories;

IDM (any type of diabetes), late preterm (35 or 36 wk gestation), SGA (BW < 10th centile or < 2.5 kg), LBW (birthweight > 90th centile or > 4.5 kg), maternal use of β-blockers.

Blood glucose was measured at 2 h of age and then AC feeds every 2 to 4 h for at least the first 12 h.  This was continued until an infant had 3 consecutive blood glucose concentrations of 2.6 mmmol/L.  With a primary outcome of hypoglycemia in the first 48 hours their power calculation dictated that a total sample size of 415 babies (66 in each treatment arm, 33 in each placebo arm) was needed which thankfully they achieved which means we can believe the results if they found no difference!

What did they find?

One might think that multiple doses and/or higher doses of glucose gel would be better than one dose but curiously they found that the tried and true single dose of 0.5 mL/kg X 1 offered the best result.  “Babies randomised to any dose of dextrose gel were less likely to develop hypoglycaemia than those randomised to placebo (RR 0.79, 95% CI 0.64–0.98, p = 0.03; number needed to 10.”

Looking at the different cumulative doses, the only dosing with a 95% confidence interval that does not cross 1 was the single dosing.  Higher and longer dosing showed no statistical difference in the likelihood of becoming hypoglycemic in the first 48 hours.  As was found in the sugar babies study, admission to NICU was no different between groups and in this study as with the sugar baby study if one looked at hypoglycemia as a cause for admission there was a slight benefit.  Curiously, while the previous study suggested a benefit to the rate of breastfeeding after discharge this was not noted here.

How might we interpret these results?

The randomized nature of this study compared to the one reviewed in part I leads me to trust these findings a little more than the previous paper.  What this confirms in my mind is that giving glucose gel prophylaxis to at risk infants likely prevents hypoglycemia in some at risk infants and given that there were no significant adverse events (other than messiness of administration), this may be a strategy that some units wish to try out.  When a low blood glucose did occur it was later in the group randomized to glucose gel at a little over 3 hours instead of 2 hours.  The fact that higher or multiple dosing of glucose gel given prophylactically didn’t work leads me to speculate this may be due to a surge of insulin.  Giving multiple doses or higher doses may trigger a normal response of insulin in a baby not at risk of hypoglycemia but in others who might already have a high baseline production of insulin such as in IDMs this surge might lead to hypoglycemia.  This also reinforces the thought that multiple doses of glucose gel in babies with hypoglycemia should be avoided as one may just drive insulin production and the treatment may become counterproductive.

In the end, I think these two papers provide some food for thought.  Does it make sense to provide glucose gel before a problem occurs?  We already try and feed at risk babies before 2 hours so would the glucose gel provide an added kick or just delay the finding of hypoglycemia to a later point. One dose may do the trick though.

A reader of my Facebook page sent me a picture of the hPOD trial which is underway which I hope will definitively put this question to rest.  For more on the trial you can watch Dr. Harding speak about the trial here.

Can prophylactic dextrose gel prevent babies from becoming hypoglycemic?

Can prophylactic dextrose gel prevent babies from becoming hypoglycemic?

I have written a number of times already on the topic of dextrose gels. Previous posts have largely focused on the positive impacts of reduction in NICU admissions, better breastfeeding rates and comparable outcomes for development into childhood when these gels are used. The papers thus far have looked at the effectiveness of gel in patients who have become hypoglycemic and are in need of treatment. The question then remains as to whether it would be possible to provide dextrose gel to infants who are deemed to be at risk of hypoglycemia to see if we could reduce the number of patients who ultimately do become so and require admission.

Answering that question

Recently, Coors et al published Prophylactic Dextrose Gel Does Not Prevent Neonatal Hypoglycemia: A Quasi-Experimental Pilot Study. What they mean by Quasi-Experimental is that due to availability of researchers at off hours to obtain consent they were unable to produce a randomized controlled trial. What they were able to do was compare a group that had the following risk factors (late preterm, birth weight <2500 or >4000 g, and infants of mothers with diabetes) that they obtained consent for giving dextrose gel following a feed to a control group that had the same risk factors but no consent for participation. The protocol was that each infant would be offered a breastfeed or formula feed after birth followed by 40% dextrose gel (instaglucose) and then get a POC glucose measurement 30 minutes later. A protocol was then used based on different glucose results to determine whether the next step would be a repeat attempt with feeding and gel or if an IV was needed to resolve the issue.

To be sure, there was big hope in this study as imagine if you could prevent a patient from becoming hypoglycemic and requiring IV dextrose followed by admission to a unit.  Sadly though what they found was absolutely no impact of such a strategy.  Compared with the control group there was no difference in capillary glucose after provision of dextrose gel (52.1 ± 17.1 vs 50.5 ± 15.3 mg/dL, P = .69).  One might speculate that this is because there are differing driving forces for hypoglycemia and indeed that was the case here where there were more IDMs and earlier GA in the prophylactic group.  On the other hand there were more LGA infants in the control group which might put them at higher risk.  When these factors were analyzed though to determine whether they played a role in the lack of results they were found not to. Moreover, looking at rates of admission to the NICU for hypoglycemia there were also no benefits shown.  Some benefits were seen in breastfeeding duration and a reduction in formula volumes consistent with previous studies examining the effect of glucose gel on both which is a win I suppose.

It may also be that when you take a large group of babies with risks for hypoglycemia but many were never going to become hypoglycemic, those who would have had a normal sugar anyway dilute out any effect.  These infants have a retained ability to produce insulin in response to a rising blood glucose and to limit the upward movement of their glucose levels.  As such what if the following example is at work? Let’s say there are 200 babies who have risk factors for hypoglycemia and half get glucose gel.  Of the 100 about 20% will actually go on to have a low blood sugar after birth.  What if there is a 50% reduction in this group of low blood sugars so that only 10 develop low blood glucose instead of 20.  When you look at the results you would find in the prophylaxis group 10/100 babies have a low blood sugar vs 20/100.  This might not be enough of a sample size to demonstrate a difference as the babies who were destined not to have hypoglycemia dilute out the effect.  A crude example for sure but when the incidence of the problem is low, such effects may be lost.

A Tale of Two Papers

This post is actually part of a series with this being part 1.  Part 2 will look at a study that came up with a different conclusion.  How can two papers asking the same question come up with different answers?  That is the story of medicine but in the next part we will look at a paper that suggests this strategy does work and look at possible reasons why.

Screening for congenital heart disease; will early discharge be its ruin?

Screening for congenital heart disease; will early discharge be its ruin?

In 2017 the Canadian Pediatric Society published the practice point Pulse oximetry screening in newborns to enhance detection of critical congenital heart disease.  In this document we recommended universal screening for CCHDs but stressed the following:

“Recognizing that delivery and time of discharge practices vary across Canada, the timing of testing should be individualized for each centre and (ideally) occur after 24 hours postbirth to lower FP results. And because the intent is to screen newborns before they develop symptoms, the goal should be to perform screening before they reach 36 hours of age.”

This recommendation was put in place to minimize the number of false positive results and prevent Pediatricians and Cardiologists nationwide from being inundated with requests to rule out CCHD as earlier testing may pick up other causes for low oxygen saturation such as TTN.  The issue remains though that many patients are indeed discharged before 24 hours and in the case of midwife deliveries either in centres or in the home what do we do?

A Population Study From the Netherlands May Be of Help Here

Researchers in the Netherlands had a golden opportunity to answer this question as a significant proportion of births occur there in the home under the care of a midwife. Accuracy of Pulse Oximetry Screening for Critical Congenital Heart Defects after Home Birth and Early Postnatal Discharge by Ilona C. Narayen et al was published this month in J Peds. About 30% of births are cared for by a midwife with about 20% occurring in the home. The authors chose to study this population of infants who were all above 35 weeks gestation and not admitted to an intensive care nor had suspicion of CCHD prior to delivery. The timing of the screening was altered from the typical 24-48 hours to be two time points to be more reflective of midwives practice. All patients were recruited after birth with the use of information pamphlets. The prospective protocol was screening on 2 separate moments: on day 1, at least 1 hour after birth, and on day 2 or 3 of life. The criteria for passing or failing the test are the same as those outlined in the CPS practice point. As part of the study, patients with known CCHDs were also screened separately as a different group to determine the accuracy of the screening test in patients with known CCHD.

Results

There were nearly 24000 patients born during this period. Only 49 cases of CCHD were identified by screening and of these 36 had been picked up antenatally giving a detection rate of 73%. Out of 10 patients without prenatal diagnosis who also had saturation results available the detection rate was 50%. Three of the misses were coarctation of the aorta (most likely diagnosis to be missed in other studies), pulmonary stenosis (this one surprises me) and TGA (really surprises me). The false-positive rate of pulse oximetry screening (no CCHD) was 0.92%. The specificity was over 99% meaning that if you didn’t have CCHD you were very likely to have a negative test. Not surprisingly, most false- positives occurred on day 1 (190 on day 1 vs 31 infants on day 2 or 3). There were five patients missed who were not detected either by antenatal ultrasound. These 5 negatives ultimately presented with symptoms at later time points and all but one survived (TGA) so out of 24000 births the system for detecting CCHD did reasonably well in enhancing detection as they picked up another 5 babies that had been missed antenatally narrowing the undetected from 10 down to 5.

Perhaps the most interesting thing about the study though is what they also found. As the authors state: “Importantly, 61% (134/221) of the infants with false-positive screenings proved to have significant noncardiac illnesses re- quiring intervention and medical follow-up, including infection/ sepsis (n = 31) and PPHN or transient tachypnea of the newborn (n = 88)”

There are certainly detractors of this screening approach but remember these infants were all thought to be asymptomatic. By implementing the screening program there was opportunity to potentially address infants care needs before they went on to develop more significant illness. Under appreciated TTN could lead to hypoxia and worsen and PPHN could become significantly worse as well. I think it is time to think of screening in this way as being more general and not just about finding CCHD. It is a means to identify children with CCHD OR RESPIRATORY illnesses earlier in their course and do something about it!

 

Magnetic acupuncture coming to an NICU near you?

Magnetic acupuncture coming to an NICU near you?

I would consider myself fairly open minded when it comes to care in the NICU.  I wouldn’t call myself a maverick or careless but I certainly am open to new techniques or technologies that may offer a better level of care for the babies in our unit.  When it comes to “non-Western” concepts though such as therapeutic touch, chiropractic manipulations of infants and acupuncture (needle or otherwise) I have generally been a skeptic.  I have written about such topics before with the most popular post being Laser acupuncture for neonatal abstinence syndrome.  My conclusion there was that I was not a fan of the strategy but perhaps I could be more open to non traditional therapies.

Magnetic Acupuncture

This would appear to be the newest and perhaps strangest (to me at least) approach to pain relief that I have seen.  I do love name of this study; the MAGNIFIC trial consisted of a pilot study on the use of auricular magnetic acupuncture to alleviate pain in the NICU from heel lances.  The study was published in Acta Paediatrica this month; Magnetic Non-Invasive Acupuncture for Infant Comfort (MAGNIFIC) – A single-blinded randomized controlled pilot trial.  The goal here was to measure pain scores using the PIPP scoring system for pain in the neonate before during and after a painful experience (heel lance) in the NICU.  Being a pilot study it was small with only 20 needed per arm based on the power calculation to detect a 20% difference in scores.  The intervention used small magnets placed at specific locations on the ear of the infant at least two hours before the heel lance was to occur.  Before I get into the results, the authors of the study provide references to explain how the therapy works.  Looking at the references I have to admit I was not able to obtain complete papers but the evidence is generally it would appear from adult patients.  The explanation has to do with the magnetic field increasing blood flow to the area the magnet is applied to and in addition another reference suggests that there are affects the orbitofrontal and limbic regions which then impacts neurohormonal responses as seen in functional MRI.  The evidence to support this is I would have thought would be pretty sparse but I was surprised to find a literature review on the subject that looked at 42 studies on the topic.  The finding was that 88% of the studies reported a therapeutic effect.  The conclusion though of the review was that the quality of the included studies was a bit sketchy for the most part so was not able to find that this should be a recommended therapy.

So what were the results?

Despite my clear skepticism what this study did well was that aside from the magnets, the intervention was the same.  Twenty one babies received the magnetic treatments vs 19 placebo.  There was a difference in the gestational ages of the babies with the magnet treated infants being about two weeks older (35 vs 33 weeks).  What difference that might in and of itself have on the PIPPs scoring I am not sure.  The stickers were applied to the ears with and without magnets in a randomized fashion and the nurses instructed to score them using the PIPP scoring system.  Interestingly, as per their unit policy all babies received sucrose as well before the intervention of a heel lance so I suppose the information gleaned here would be the use of magnets as an adjunctive treatment.  No difference was noted in the two groups before and after the heel lance but during the procedure the magnet treated infants had a difference in means (SD): 5.9 (3.7) v 8.3 (4.7), p=0.04).  No differences were found in secondary measures such as HR or saturation and no adverse effects were noted.  The authors conclusions were that it was feasible and appears safe and as with most pilot studies warrants further larger studies to verify the results.

Should we run out and buy it?

One of the issues I have with the study is that in the introduction they mention that this treatment might be useful where kangaroo care (KC) is not such as a critically ill infant.  Having placed infants who are quite sick in KC and watched wonderful stability arise I am not sure if the unit in question under utilizes this important modality for comfort.

The second and perhaps biggest issue I have here is that although the primary outcome was reached it does seem that there was some fishing going on here.  By that I mean there were three PIPP scores examined (before, during and after) and one barely reached statistical significance.  My hunch is that indeed this was reached by chance rather than it being a real difference.

The last concern is that while the intervention was done in a blinded and randomized fashion, the evidence supporting the use of this in the first place is not strong.  Taking this into account and adding the previous concern in as well and I have strong doubts that this is indeed “for real”.  I doubt this will be the last we will hear about it and while my skepticism continues I have to admit if a larger study is produced I will be willing and interested to read it.

 

You don't plan to fail. You fail to plan

You don't plan to fail. You fail to plan

I am fortunate to work with a group of inter-professionals who strive for perfection.  When you connect such people with those with skills in multimedia you create the opportunity for education.  I can’t say enough about the power of education and moreover the ability to improve patient outcomes when it is done well.

With this post I am going to be starting to share a collection of videos that I will release from time to time.  The hope with any release like this is that you the reader wherever you are may find some use from these short clips.  My thanks to the team that put these together as the quality is beyond compare and the HD quality is great for viewing on any device.

Placing A Chest Tube Can Be A Difficult Thing

As I said to a colleague in training the other day, a chest tube may seem daunting but once you see how it is done it loses some of its intimidation.  Having said that, once you see it placed it can be a long time between opportunities for you to view another.  That is where having a repository of videos comes in that you can watch prior to the next opportunity.  These very short clips are easy to access when needed and may calm the nerves the next time you are called to place a chest tube.

A Word About Chest Tubes

The videos in question demonstrate how to place a Thal quick chest tube. figure-1-the-thal-quick-chest-tube-set-including-introducer-needle-wire-guideIn case this looks foreign to you it may be because you are using the older generation style of chest tubes that come equipped with a trocar.  Even without the use of the trocar, these rigid tubes carry a significant risk of lung laceration or other tissue injury.  For a review of such complications related to chest tube insertion see Thoracostomy tubes: A comprehensive review of complications and related topics.

The jury as they say is still out with respect to the use of these softer chest tube sets.  There is no question that they are easier to place than the traditional thoracostomy tube.  Their pliability though does carry a significant risk of kinking or blockage as we have seen in some patients when the Thal chest tube set is used to drain fluid in particular.  Less of an issue with air leaks.

Start of a series

This post I suppose marks a slightly new direction for the blog.  While I thoroughly enjoy educating you with the posts about topics of interest I see an opportunity to help those who are more visual in their learning.  The videos will be posted over the next while with accompanying written posts such as this.  They can be accessed on my Youtube channel at

All Things Neonatal YouTube

To receive regular updates as new videos are added feel free to subscribe!

Lastly a big thank you to NS, RH and GS without whom none of this would have been possible!