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AllThingsNeonatal

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About AllThingsNeonatal

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  • First name
    Michael
  • Last name
    Narvey
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    Neonatologist
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    University of Manitoba
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    Winnipeg, Canada

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  1. Much has been written about methylxanthines over the years with the main questions initially being, “should we use them?”, “how big a dose should we use” and of course “theophylline vs caffeine”. At least in our units and in most others I know of caffeine seems to reign supreme and while there remains some discussion about whether dosing for maintenance of 2.5 -5 mg/kg/d of caffeine base or 5 – 10 mg/kg/d is the right way to go I think most favour the lower dose. We also know from the CAP study that not only does caffeine work to treat apnea of prematurity but it also appears to reduce the risk of BPD, PDA and duration of oxygen therapy to name a few benefits. Although initially promising as providing a benefit by improving neurodevelopmental outcomes in those who received it, by 5 and 11 years these benefits seem to disappear with only mild motor differences being seen. Turning to a new question The new query though is how long to treat? Many units will typically stop caffeine somewhere between 33-35 weeks PMA on the grounds that most babies by then should have outgrown their irregular respiration patterns and have enough pulmonary reserve to withstand a little periodic breathing. Certainly there are those who prove that they truly still need their caffeine and on occasion I have sent some babies home with caffeine when they are fully fed and otherwise able to go home but just can’t seem to stabilize their breathing enough to be off a monitor without caffeine. Then there is also more recent data suggesting that due to intermittent hypoxic episodes in the smallest of infants at term equivalent age, a longer duration of therapy might be advisable for these ELBWs. What really hasn’t been looked at well though is what duration of caffeine might be associated with the best neurodevelopmental outcomes. While I would love to see a prospective study to tackle this question for now we will have to do with one that while retrospective does an admirable job of searching for an answer. The Calgary Neonatal Group May Have The Answer Lodha A et al recently published the paper Does duration of caffeine therapy in preterm infants born ≤1250 g at birth influence neurodevelopmental (ND) outcomes at 3 years of age? This retrospective study looked at infants under 1250g at birth who were treated within one week of age with caffeine and divided them into three categories based on duration of caffeine therapy. The groups were as follows, early cessation of caffeine ≤ 14 days (ECC), intermediate cessation of caffeine 15–30 days (ICC), and late cessation of caffeine >30 days (LCC). In total there were 508 eligible infants with 448 (88%) seen at 3 years CA at follow-up. ECC (n = 139), ICC (n = 122) and LCC (n = 187). The primary outcome here was ND at 3 years of age while a host of secondary outcomes were also examined such as RDS, PDA, BPD, ROP as typical morbidities. It made sense to look at these since provision of caffeine had previously been shown to modify such outcomes. Did they find a benefit? Sadly there did not appear to be any benefit regardless of which group infants fell in with respect to duration of caffeine when it came to ND. When looking at secondary outcomes there were a few key differences found which favoured the ICC group. These infants had the lowest days of supplemental oxygen, hospital stay ROP and total days of ventilation. This middle group also had a median GA 1 week older at 27 weeks than the other two groups. The authors however did a logistic regression and ruled out the improvement based on the advanced GA. The group with the lowest use of caffeine had higher number of days on supplemental oxygen and higher days of ventilation on average than the middle but not the high caffeine group. It is tempting to blame the result for the longer caffeine group on these being babies that were just sicker and therefore needed caffeine longer. On the other hand the babies that were treated with caffeine for less than two weeks appear to have likely needed it longer as they needed longer durations of oxygen and were ventilated longer so perhaps were under treated. What is fair to say though is that the short and long groups having longer median days of ventilation were more likey to have morbidities associated with that being worse ROP and need for O2. In short they likely had more lung damage. What is really puzzling to me is that with a median GA of 27-28 weeks some of these kids were off caffeine before 30 weeks PMA and in the middle group for the most part before 32 weeks! If they were in need of O2 and ventilation for at least two weeks maybe they needed more caffeine or perhaps the babies in these groups were just less sick? What is missing? There is another potential answer to why the middle group did the best. In the methods section the authors acknowledge that for each infant caffeine was loaded at 10 mg/kg/d. What we don’t know though is what the cumulative dose was for the different groups. The range of dosing was from 2.5-5 mg/kg/d for maintenance. Lets say there was an over representation of babies on 2.5 mg/kg/d in the short and long duration groups compared to the middle group. Could this actually be the reason behind the difference in outcomes? If for example the dosing on average was lower in these two groups might it be that with less respiratory drive the babies in those groups needed faster ventilator rates with longer durations of support leading to more lung damage and with it the rest of the morbidities that followed? It would be interesting to see such data to determine if the two groups were indeed dosed on average lower by looking at median doses and total cumulative doses including miniloads along the way. We know that duration may need to be prolonged in some patients but we also know that dose matters and without knowing this piece of information it is tough to come to a conclusion about how long exactly to treat. What this study does though is beg for a prospective study to determine when one should stop caffeine as that answer eludes us!
  2. If I look back on my career there have been many things I have been passionate about but the one that sticks out as the most longstanding is premedicating newborns prior to non-emergent intubation. The bolded words in the last sentence are meant to reinforce that in the setting of a newborn who is deteriorating rapidly it would be inappropriate to wait for medications to be drawn up if the infant is already experiencing severe oxygen desaturation and/or bradycardia. The CPS Fetus and Newborn committee of which I am a member has a statement on the use of premedication which seems as relevant today as when it was first developed. In this statement the suggested cocktail of atropine, fentanyl and succinylcholine is recommended and having used it in our centre I can confirm that it is effective. In spite of this recommendation by our national organization there remain those who are skeptical of the need for this altogether and then there are others who continue to search for a better cocktail. Since I am at the annual conference for the CPS in Quebec city I thought it would be appropriate to provide a few comments on this topic. Three concerns with rapid sequence induction (RSI) for premedication before intubation 1. "I don't need it. I don't have any trouble intubating a newborn" - This is perhaps the most common reason I hear naysayers raise. There is no question that an 60-90 kg practitioner can overpower a < 5kg infant and in particular an ELBW infant weighing < 1 kg. This misses the point though. Premedicating has been shown to increase success on the first attempt and shorten times to intubation. Dempsey 2006, Roberts 2006, Carbajal 2007, Lemyre 2009 2. "I usually get in on the first attempt and am very slick so risk of injury is less." Not really true overall. No doubt there are those individuals who are highly successful but overall the risk of adverse events is reduced with premedication. (Marshall 1984, Lemyre 2009). I would also proudly add another Canadian study from Edmonton by Dr. Byrne and Dr. Barrington who performed 249 consecutive intubations with predication and noted minimal side effects but high success rates at first pass. 3. "Intubation is not a painful procedure". This one is somewhat tough to obtain a true answer for as the neonate of course cannot speak to this. There is evidence available again from Canadian colleagues in 1984 and 1989 that would suggest that infants at the very least experience discomfort or show physiologic signs of stress when intubated using an "awake" approach. In 1984 Kelly and Finer in Edmonton published Nasotracheal intubation in the neonate: physiologic responses and effects of atropine and pancuronium. This randomized study of atropine with or without pancuronium vs control demonstrated intracranial hypertension only in those infants in the control arm with premedication ameliorating this finding. Similarly, in 1989 Barrington, Finer and the late Phil Etches also in Edmonton published Succinylcholine and atropine for premedication of the newborn infant before nasotracheal intubation: a randomized, controlled trial. This small study of 20 infants demonstrated the same finding of elimination of intracranial hypertension with premedication. At the very least I would suggest that having a laryngoscope blade put in your oral cavity while awake must be uncomfortable. If you still doubt that statement ask yourself whether you would want sedation if you needed to be intubated? Still feel the same way about babies not needing any? 4. What if I sedate and paralyze and there is a critical airway? Well this one may be something to consider. If one knows there is a large mass such as a cystic hygroma it may be best to leave the sedation or at least the paralysis out. The concern though that there might be an internal mass or obstruction that we just don't know about seems a little unfounded as a justification for avoiding medications though. Do we have the right cocktail? The short answer is "I don't know". What I do know is that the use of atropine, an opioid and a muscle relaxant seems to provide good conditions for intubating newborns. We are in the era of refinement though and as a recent paper suggests, there could be alternatives to consider;Effect of Atropine With Propofol vs Atropine With Atracurium and Sufentanil on Oxygen Desaturation in Neonates Requiring Nonemergency IntubationA Randomized Clinical Trial. I personally like the idea of a two drug combination for intubating vs.. three as it leaves one less drug to worry about a medication error with. There are many papers out there looking at different drug combinations. This one though didn't find a difference between the two combinations in terms of prolonged desaturations between the two groups which was the primary outcome. Interestingly though the process of intubating was longer with atropine and propofol. Given some peoples reluctance to use RSI at all, any drug combination which adds time to the the procedure is unlikely to go over well. Stay tuned though as I am sure there will be many other combinations over the next few years to try out!
  3. AllThingsNeonatal

    It’s time to approach nutrition in extreme preemies as if it were a drug

    It depends on the analyzer I suppose you are using but we recently received a quote for one that is about 30-35K US. Operating costs to sample 5-10 breast milk samples a week are about 1200 US per year.
  4. One of the benefits of operating this site is that I often learn from the people reading these posts as they share their perspectives. On a recent trip I was reunited with Boubou Halberg a Neonatologist from Sweden whom I hadn’t seen in many years. I missed him on my last trip to Stockholm as I couldn’t make it to Karolinska University but we managed to meet each other in the end. As we caught up and he learned that I operated this site he passed along a paper of his that left an impact on me and I thought I would share with you. When we think about treating an infant with a medicinal product, we often think about getting the right drug, right dose and right administration (IV, IM or oral) for maximum benefit to the patient. When it comes to nutrition we have certainly come a long way and have come to rely on registered dieticians where I work to handle a lot of the planning when it comes to getting the right prescription for our patients. We seem comfortable though making some assumptions when it comes to nutrition that we would never make with respect to their drug counterparts. More on that later… A Swedish Journey to Ponder Westin R and colleagues (one of whom is my above acquaintance) published a seven year retrospective nutritional journey in 2017 from Stockholm entitled Improved nutrition for extremely preterm infants: A population based observational study. After recognizing that over this seven year period they had made some significant changes to the way they approached nutrition, they chose to see what effect this had on growth of their infants from 22 0/7 to 26 6/7 weeks over this time by examining four epochs (2004-5, 2006-7, 2008-9 and 2010-11. What were these changes? They are summarized beautifully in the following figure. Not included in the figure was a progressive change as well to a more aggressive position of early nutrition in the first few days of life using higher protein, fat and calories as well as changes to the type of lipid provided being initially soy based and then changing to one primarily derived from olive oil. Protein targets in the first days to weeks climbed from the low 2s to the mid 3s in gram/kg/d while provision of lipid as an example doubled from the first epoch to the last ending with a median lipid provision in the first three days of just over 2 g/kg/d. While figure 3 from the paper demonstrates that regardless of time period there were declines in growth across all three measurements compared to expected growth patterns, when one compares the first epoch in 2004-2005 with the last 2010-11 there were significant protective effects of the nutritional strategy in place. The anticipated growth used as a standard was based on the Fenton growth curves. What this tells us of course is that we have improved but still have work to do. Some of the nutritional sources as well were donor breast milk and based on comments coming back from this years Pediatric Academic Society meeting we may need to improve how that is prepared as growth failure is being noted in babies who are receiving donated rather than fresh mother’s own milk. I suspect there will be more on that as time goes by. Knowing where you started is likely critical! One advantage they have in Sweden is that they know what is actually in the breast milk they provide. Since 1998 the babies represented in this paper have had their nutritional support directed by analyzing what is in the milk provided by an analyzer. Knowing the caloric density and content of protein, carbohydrates and fats goes a long way to providing a nutritional prescription for individual infants. This is very much personalized medicine and it would appear the Swedes are ahead of the curve when it comes to this. in our units we have long assumed a caloric density of about 68 cal/100mL. What if a mother is producing milk akin to “skim milk” while another is producing a “milkshake”. This likely explains why some babies despite us being told they should be getting enough calories just seem to fail to thrive. I can only speculate what the growth curves shown above would look like if we did the same study in units that actually take a best guess as to the nutritional content of the milk they provide. This paper gives me hope that when it comes to nutrition we are indeed moving in the right direction as most units become more aggressive with time. What we need to do though is think about nutrition no different than writing prescriptions for the drugs we use and use as much information as we can to get the dosing right for the individual patient!
  5. AllThingsNeonatal

    the Global Village(-s) of Neonatology

    Thank you for the compliment and congratulations to all that you have accomplished on 99NICU. The classroom is now virtual and your site reflects the needs of the adult learner to absorb information at their own speed and indeed on the topics they are most interested in
  6. 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.
  7. 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.
  8. 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!
  9. For almost a decade now confirmation of intubation is to be done using detection of exhaled CO2. The 7th Edition of NRP has the following to say about confirmation of ETT placement “The primary methods of confirming endotracheal tube placement within the trachea are detecting exhaled CO2 and a rapidly rising heart rate.” They further acknowledge that there are two options for determining the presence of CO2 “There are 2 types of CO2 detectors available. Colorimetric devices change color in the presence of CO2. These are the most commonly used devices in the delivery room. Capnographs are electronic monitors that display the CO2 concentration with each breath.” The NRP program stops short of recommending one versus the other. I don’t have access to the costs of the colorimetric detectors but I would imagine they are MUCH cheaper than the equipment and sensors required to perform capnography using the NM3 monitor as an example. The real question though is if capnography is truly better and might change practice and create a safer resuscitation, is it the way to go? Fast but not fast enough? So we have a direct comparison to look at. Hunt KA st al published Detection of exhaled carbon dioxide following intubation during resuscitation at delivery this month. They started from the standpoint of knowing from the manufacturer of the Pedicap that it takes a partial pressure of CO2 of 4 mm Hg to begin seeing a colour change from purple to yellow but only when the CO2 reaches 15 mm Hg do you see a consistent colour change with that device. The capnograph from the NM3 monitor on the other hand is quantitative so is able to accurately display when those two thresholds are reached. This allowed the group to compare how long it took to see the first colour change compared to any detection of CO2 and then at the 4 and 15 mm Hg levels to see which is the quicker method of detection. It is an interesting question as what would happen if you were in a resuscitation and the person intubates and swears that they are in but there is no colour change for 5, 10 or 15 seconds or longer? At what point do you pull the ETT? Compare that with a quantitative method in which there is CO2 present but it is lower than 4. Would you leave the tube in and use more pressure (either PIP/PEEP or both?)? Before looking at the results, it will not shock you that ANY CO2 should be detected faster than two thresholds but does it make a difference to your resuscitation? The Head to Head Comparison The study was done retrospectively for 64 infants with a confirmed intubation using the NM3 monitor and capnography. Notably the centre did not use a colorimetric detector as a comparison group but rather relied on the manufacturers data indicating the 4 and 15 mm Hg thresholds for colour changes. The mean age of patients intubated was 27 weeks with a range of 23 – 34 weeks. The results I believe show something quite interesting and informative. Median time secs (range) Earliest CO2 detection 3.7 (0 – 44s) 4 mm Hg 5.3 (0 – 727) 15 mm Hg 8.1 (0 – 727) I wouldn’t worry too much about a difference of 1.6 seconds to start getting a colour change but it is the range that has me a little worried. The vast majority of the patients demonstrated a level of 4 or 15 mm Hg within 50 seconds although many were found to take 25-50 seconds. When compared to a highest level of 44 seconds in the first detection of CO2 group it leads one to scratch their head. How many times have you been in a resuscitation and with no CO2 change you keep the ETT in past 25 seconds? Looking closer at the patients, there were 12 patients that took more than 30 seconds to reach a threshold of 4 mm Hg. All but one of the patients had a heart rate in between 60-85. Additionally there was an inverse relationship found between gestational age and time to detection. In other words, the smallest of the babies in the study took the longest to establish the threshold of 4 and 15 mm Hg. Putting it into context? What this study tells me is that the most fragile of infants may take the longest time to register a colour change using the colorimetric devices. It may well be that these infants take longer to open up their pulmonary vasculature and deliver CO2 to the alveoli. As well these same infants may take longer to open the lung and exhale the CO2. I suppose I worry that when a resuscitation is not going well and an infant at 25 weeks is bradycardic and being given PPV through an ETT without colour change, are they really not intubated? In our own centre we use capnometry in these infants (looks for a wave form of CO2) which may be the best option if you are looking to avoid purchasing equipment for quantitative CO2 measurements. I do worry though that in places where the colorimetric devices are used for all there will be patients who are extubated due to the thought that they in fact have an esophageal intubation when the truth is they just need time to get the CO2 high enough to register a change in colour. Anyways, this is food for thought and a chance to look at your own practice and see if it is in need of a tweak…
  10. Hypoglycemia has to be one of the most common conditions that we screen for or treat in the NICU and moreover in newborn care in general. The Canadian Pediatric Society identifies small for gestational age infants (weight <10th percentile), large for gestational age (LGA; weight > 90th percentile) infants, infants of diabetic mothers (IDMs) and preterm infants as being high risk for hypoglycemia. It is advised then to screen such babies in the absence of symptoms for hypoglycemia 2 hours after birth after a feed has been provided (whether by breast or bottle). I am sure though if you ask just about any practitioner out there, they will tell you a story about a baby with “no risk factors” who had hypoglycemia. These one-off cases have the effect though of making us want to test everyone for fear that we will miss one. If that is the case though should we be recommending that all babies get at least one check? The Canadian Pediatric Surveillance Program (CPSP) The CPSP is a branch of the Canadian Pediatric Society that “provides an innovative means to undertake active paediatric surveillance and increase awareness of childhood disorders that are high in disability, morbidity, mortality and economic cost to society, despite their low frequency. I submit my surveys each month as i hope other Canadian Pediatricians do and help to determine the impact of these rare conditions in our Canadian population. Like with any survey we rely on people taking the time to submit but there is always the risk that what is being sent in under represents the true burden of illness as some cases may not be identified. Having said that, it is the best we have! Turning our attention to hypoglycemia in low risk newborns From April 2014 to March 2016 the CPSP searched for these types of patients and just published the results of their findings in Hypoglycemia in unmonitored full-term newborns—a surveillance study by Flavin MP et al. What I like about the study is that they have been able to look at a group of babies that fall outside those identified as being at risk in the CPS statement Screening guidelines for newborns at risk for low blood glucose. They were looking for severe hypoglycemia by using a threshold of < 2.0 mmol/L (36 mg/dl) and all infants must have received IV dextrose. In the end after excluding ineligible cases they had 93 babies who met criteria. Based on the Canadian birth rate this translates to an incidence of 1 in every 8378 births. These babies were all supposed to be low risk but there were in fact clues that while not strictly identified as risks in the CPS statement could have increased the likelihood of a low blood glucose. Twenty three percent of mothers had maternal hypertension and another 23% were obese while 47% had excessive weight gain during pregnancy. Furthermore, 8% of mothers were treated with a beta blocker (most likely labetalol I would think) during pregnancy which is a risk factor for hypoglycemia although not specifically cited in the current CPS statement. A concerning finding as well was the likelihood of severe symptoms in this group on presentation. Twenty percent presented with major clinical signs (seizure, apnea or cyanosis). Median glucose levels at presentation were much lower than those without major signs (median = 0.8 mmol/L, interquartile range [IQR] = 0.5 versus 1.6 mmol/L, IQR = 0.7; P < 0.001). Lastly, providers were asked about neurodevelopmental concerns at discharge approximately 20% were thought to have issues. Are these patients really low risk though? Twenty five percent of the patients submitted had a birth weight less than the 10%ile for GA. These patients as per the CPS guideline recommendations are actually considered at risk and should have been screened. The second issue to address has to do with the way we diagnose diabetes in pregnancy. All women are provided with the oral glucose tolerance test around 28 weeks of pregnancy. No test is perfect but it is the best we have. Women who have excessive weight gain in pregnancy (almost 50% of the cohort) are at higher risk of developing diabetes or some degree of insulin resistance as are those who are classified as obese. I have long suspected and think it may be the case here that some babies who do not meet the criteria for screening as their mothers do not have a diagnosis of GDM actually are at risk due to some degree of insulin resistance or perhaps their mothers develop GDM later. The evidence for this are the occasional LGA babies who are born to mothers without a GDM diagnosis but who clearly have been exposed to high insulin levels as they behave like such affected infants with poor feeding and low sugars in the newborn period. The authors here comment on those that were SGA but how many in this cohort were LGA? The effect of hypertension can also not be minimized which was present in about a quarter of patients. These babies while not being officially SGA may have experienced a deceleration in weight gain in the last few weeks but remained above the 10%ile. These infants would not have the glycogen stores to transition successfully but would not be targeted as being at risk by the current definitions. Should we be screening everyone then? If we acknowledge that about 25% were IUGR in this study (<10%ile) and should have been screened, the expected rate would be 1:1170 births alone. In Manitoba with our 17000 births a year we would capture about two extra babies a year which translates into a low of pokes for a lot of healthy babies. Given the further information that 1:5 babies who are identified may have neurodevelopmental concerns it would take about 2-3 years of testing to prevent one concern. That pick up rate for me is far too low to subject so many babies to testing. What this study though does highlight is the need to view risk factors a little less strictly. Babies who are almost meeting the criteria for being LGA or those whose mother’s have taken lebetalol should have a low threshold for screening. Should hypertension on medications, excessive maternal weight gain or obesity in the mother be considered a risk? What I didn’t see in the end of this study were patients who truly were AGA, being born to healthy non overweight mothers presenting as high risk. Maybe what is really needed based on this study is to re-evaluate what we consider at risk. In the meantime, maybe we should be testing a few extra babies who fall into these “lesser” risk categories. Better yet a study isolating such patients and looking at the frequency of hypoglycemia in these patients is warranted to get a better idea of whether they are indeed risks.
  11. Skin to skin care or kangaroo care is all the rage and I am the first one to offer my support for it. Questions persist though as to whether from a physiological standpoint, babies are more stable in an isolette in a quiet environment or out in the open on their mother or father’s chests. Bornhorst et al expressed caution in their study Skin-to-skin (kangaroo) care, respiratory control, and thermoregulation. In a surprising finding, babies with an average gestational age of 29 weeks were monitored for a number of physiological parameters and found to have more frequent apnea and higher heart rates than when in an isolette. The study was small though and while there were statistical differences in these parameters they may not have had much clinical significance (1.5 to 2.8 per hour for apnea, bradycardia or desaturation events). Furthermore, does an increase in such events translate into any changes in cerebral oxygenation that might in turn have implications for later development? Tough to say based on a study of this magnitude but it certainly does raise some eyebrows. What if we could look at cerebral oxygenation? As you might have guessed, that is exactly what has been done by Lorenz L et al in their recent paper Cerebral oxygenation during skin-to-skin care in preterm infants not receiving respiratory support.The goal of this study was to look at 40 preterm infants without any respiratory distress and determine whether cerebral oxygenation (rStO2)was better in their isolette or in skin to skin care (SSC). They allowed each infant to serve as their own control by have three 90 minute periods each including the first thirty minutes as a washout period. Each infant started their monitoring in the isolette then went to SSC then back to the isolette. The primary outcome the power calculation was based on was the difference in rStO2 between SSC and in the isolette. Secondary measures looked at such outcomes as HR, O2 sat, active and quiet sleep percentages, bradycardic events as lastly periods of cerebral hypoxia or hyperoxia. Normal cerebral oxygenation was defined as being between 55 to 85%. Surprising results? Perhaps its the start of a trend but again the results were a bit surprising showing a better rStO2 when in the isolette (−1.3 (−2.2 to −0.4)%, p<0.01). Other results are summarized in the table below: Mean difference in outcomes Variable SSC Isolette Difference in mean p rStO2 73.6 74.8 -1.3 <0.01 SpO2 (median) 97 97 -1.1 0.02 HR 161 156 5 <0.01 % time in quiet sleep 58.6 34.6 24 <0.01 No differences were seen in bradycardic events, apnea, cerebral hypoexmia or hyperoxemia. The authors found that SSC periods in fact failed the “non-inferiority” testing indicating that from a rStO2 standpoint, babies were more stable when not doing SSC! Taking a closer look though one could argue that even if this is true does it really matter? What is the impact on a growing preterm infant if their cerebral oxygenation is 1.3 percentage points on average lower during SSC or if their HR is 5 beats per minute faster? I can’t help but think that this is an example of statistical significance without clinical significance. Nonetheless, if there isn’t a superiority of these parameters it does leave one asking “should we keep at it?” Benefits of skin to skin care Important outcomes such as reductions in mortality and improved breastfeeding rates cannot be ignored or the positive effects on family bonding that ensue. Some will argue though that the impacts on mortality certainly may be relevant in developing countries where resources are scarce but would we see the same benefits in developed nations. The authors did find a difference though in this study that I think benefits developing preterm infants across the board no matter which country you are in. That benefit is that of Quiet Sleep (QS). As preterm infants develop they tend to spend more time in QS compared to active sleep (AS). From Doussard- Roossevelt J, “Quiet sleep consists of periods of quiescence with regular respiration and heart rate, and synchronous EEG patterns. Active sleep consists of periods of movement with irregular respiration and heart rate, and desynchronous EEG patterns.” In the above table one sees that the percentage of time in QS was significantly increased compared to AS when in SSC. This is important as neurodevelopment is thought to advance during periods of QS as preterm infants age. There may be little difference favouring less oxygen extraction during isolette times but maybe that isn’t such a good thing? Could it be that the small statistical difference in oxygen extraction is because the brain is more active in laying down tracks and making connections? Totally speculative on my part but all that extra quiet sleep has got to be good for something. To answer the question of this post in the title I think the answer is a resounding yes for the more stable infant. What we don’t know at the moment except from anecdotal reports of babies doing better in SSC when really sick is whether on average critically ill babies will be better off in SSC. I suspect the answer is that some will and some won’t. While we like to keep things simple and have a one size fits all answer for most of our questions in the NICU, this one may not be so simple. For now I think we keep promoting SSC for even our sick patients but need to be honest with ourselves and when a patient just isn’t ready for the handling admit it and try again when more stable. For the more stable patient though I think giving more time for neurons to find other neurons and make new connections is a good thing to pursue!
  12. Caffeine seems to be good for preterm infants. We know that it reduces the frequency of apnea in the this population and moreover facilitates weaning off the ventilator in a shorter time frame than if one never received it at all. The earlier you give it also seems to make a difference as shown in the Cochrane review on prophylactic caffeine. When given in such a fashion the chances of successful extubation increase. Less time on the ventilator not surprisingly leads to less chronic lung disease which is also a good thing. I have written about caffeine more than once though so why is this post different? The question now seems to be how much caffeine is enough to get the best outcomes for our infants. Last month I wrote about the fact that as the half life of caffeine in the growing preterm infant shortens, our strategy in the NICU might be to change the dosing of caffeine as the patient ages. Some time ago though I wrote about the use of higher doses of caffeine and in the study analyzed warned that there had been a finding of increased cerebellar hemorrhage in the group randomized to receive the higher dosing. I don’t know about where you work but we are starting to see a trend towards using higher caffeine base dosing above 5 mg/kg/d. Essentially, we are at times “titrating to effect” with dosing being as high as 8-10 mg/kg/d of caffeine base. Does it work to improve meaningful outcomes? This month Vliegenthart R et al published a systematic review of all RCTs that compared a high vs low dosing strategy for caffeine in infants under 32 weeks at birth; High versus standard dose caffeine for apnoea: a systematic review. All told there were 6 studies that met the criteria for inclusion. Low dosing (all in caffeine base) was considered to be 5- 15 mg/kg with a maintenance dose of 2.5 mg/kg to 5 mg/kg. High dosing was a load of 5 mg/kg to 40 mg/kg with a maintenance of 2.5 mg/kg to 15 mg/kg. The variability in the dosing (some of which I would not consider high at all) makes the quality of the included studies questionable so a word of warning that the results may not truly be “high” vs “low” but rather “inconsistently high” vs. “inconsistently low”. The results though may show some interesting findings that I think provide some reassurance that higher dosing can allow us to sleep at night. On the positive front, while there was no benefit to BPD and mortality at 36 weeks PMA they did find if they looked only at those babies who were treated with caffeine greater than 14 days there was a statistically significant difference in both reduction of BPD and decreased risk of BPD and mortality. This makes quite a bit of sense if you think about it for a moment. If we know that caffeine improves the chances of successful extubation and we also know it reduces apnea, then who might be on caffeine for less than 2 weeks? The most stable of babies I would expect! These babies were all < 32 weeks at birth. What the review suggests is that those babies who needed caffeine for longer durations benefit the most from the higher dose. I think I can buy that. On the adverse event side, I suppose it shouldn’t surprise many that the risk of tachycardia was statistically increased with an RR of 3.4. Anyone who has explored higher dosing would certainly buy that as a side effect that we probably didn’t need an RCT to prove to us. Never mind that, have you ever taken your own pulse after a couple strong coffees in the morning? What did it not show? It’s what the study didn’t show that is almost equally interesting. The cerebellar hemorrhages seen in the study I previously wrote about were not seen at all in the other studies. There could be a lesson in there about taking too much stock in secondary outcomes in small studies… Also of note, looking at longer term outcome measures there appears to be no evidence of harm when the patients are all pooled together. The total number of patients in all of these studies was 620 which for a neonatal systematic review is not bad. A larger RCT may be needed to conclusively tell us what to do with a high and low dosing strategy that we can all agree on. What do we do though in the here and now? More specifically, if you are on call tomorrow and a baby is on 5 mg/kg/d of caffeine already, will you intubate them if they are having copious apneic events or give them a higher dose of caffeine when CPAP or NIPPV that they are already on isn’t cutting it? That is where the truth about how you feel about the evidence really comes out. These decisions are never easy but unfortunately you sometimes have to make a decision and the perfect study hasn’t been done yet. I am not sure where you sit on this but I think this study while certainly flawed gives me some comfort that nothing is truly standing out especially given the fact that some of the “high dose” studies were truly high. Will see what happens with my next patient!
  13. AllThingsNeonatal

    Gentle ventilation must start from birth

    thank you for such an insightful comment and refreshing all of our memories regarding Dr. Wung's incredible results
  14. AllThingsNeonatal

    Gentle ventilation must start from birth

    The lungs of a preterm infant are so fragile that over time pressure limited time cycled ventilation has given way to volume guaranteed (VG) or at least measured breaths. It really hasn’t been that long that this has been in vogue. As a fellow I moved from one program that only used VG modes to another program where VG may as well have been a four letter word. With time and some good research it has become evident that minimizing excessive tidal volumes by controlling the volume provided with each breath is the way to go in the NICU and was the subject of a Cochrane review entitled Volume-targeted versus pressure-limited ventilation in neonates. In case you missed it, the highlights are that neonates ventilated with volume instead of pressure limits had reduced rates of: death or BPD pneumothoraces hypocarbia severe cranial ultrasound pathologies duration of ventilation These are all outcomes that matter greatly but the question is would starting this approach earlier make an even bigger difference? Volume Ventilation In The Delivery Room I was taught a long time ago that overdistending the lungs of an ELBW in the first few breaths can make the difference between a baby who extubates quickly and one who goes onto have terribly scarred lungs and a reliance on ventilation for a protracted period of time. How do we ventilate the newborn though? Some use a self inflating bag, others an anaesthesia bag and still others a t-piece resuscitator. In each case one either attempts to deliver a PIP using the sensitivity of their hand or sets a pressure as with a t-piece resuscitator and hopes that the delivered volume gets into the lungs. The question though is how much are we giving when we do that? High or Low – Does it make a difference to rates of IVH? One of my favourite groups in Edmonton recently published the following paper; Impact of delivered tidal volume on the occurrence of intraventricular haemorrhage in preterm infants during positive pressure ventilation in the delivery room. This prospective study used a t-piece resuscitator with a flow sensor attached that was able to calculate the volume of each breath delivered over 120 seconds to babies born at < 29 weeks who required support for that duration. In each case the pressure was set at 24 for PIP and +6 for PEEP. The question on the authors’ minds was that all other things being equal (baseline characteristics of the two groups were the same) would 41 infants given a mean volume < 6 ml/kg have less IVH compared to the larger group of 124 with a mean Vt of > 6 ml/kg. Before getting into the results, the median numbers for each group were 5.3 and 8.7 mL/kg respectively for the low and high groups. The higher group having a median quite different than the mean suggests the distribution of values was skewed to the left meaning a greater number of babies were ventilated with lower values but that some ones with higher values dragged the median up. Results IVH < 6 mL/kg > 6 ml/kg p 1 5% 48% 2 2% 13% 3 0 5% 4 5% 35% Grade 3 or 4 6% 27% 0.01 All grades 12% 51% 0.008 Let’s be fair though and acknowledge that much can happen from the time a patient leaves the delivery room until the time of their head ultrasounds. The authors did a reasonable job though of accounting for these things by looking at such variables as NIRS cerebral oxygenation readings, blood pressures, rates of prophylactic indomethacin use all of which might be expected to influence rates of IVH and none were different. The message regardless from this study is that excessive tidal volume delivered after delivery is likely harmful. The problem now is what to do about it? The Quandry Unless I am mistaken there isn’t a volume regulated bag-mask device that we can turn to to control delivered tidal volume. Given that all the babies were treated the same with the same pressures I have to believe that the babies with stiffer lungs responded less in terms of lung expansion so in essence the worse the baby, the better they did in the long run at least from the IVH standpoint. The babies with the more compliant lungs may have suffered from being “too good”. Getting a good seal and providing good breaths with a BVM takes a lot of skill and practice. This is why the t-piece resuscitator grew in popularity so quickly. If you can turn a couple dials and place it over the mouth and nose of a baby you can ventilate a newborn. The challenge though is that there is no feedback. How much volume are you giving when you start with the same settings for everyone? What may seem easy is actually quite complicated in terms of knowing what we are truly delivering to the patient. I would put to you that someone far smarter than I needs to develop a commercially available BVM device with real time feedback on delivered volume rather than pressure. Being able to adjust our pressure settings whether they be manual or set on a device is needed and fast! Perhaps someone reading this might whisper in the ear of an engineer somewhere and figure out how to do this in a device that is low enough cost for everyday use.
  15. A common concern in the NICU these days is the lack of opportunity to intubate. A combination of an increasing pool of learners combined with a move towards a greater reliance on non-invasive means of respiratory support is to blame in large part. With this trend comes a declining opportunity to practice this important skill and with it a challenge to get a tube into the trachea when it really counts. One such situation is a baby with escalating FiO2 requirements who one wishes to provide surfactant to. Work continues to be done in the area of aerosolized surfactant but as of yet this is not quite ready for prime time. What if there was another way to get surfactant to where it was needed without having to instill it directly into the trachea whether through a catheter (using minimally invasive techniques) or through an endotracheal tube? Installation of surfactant into the trachea Lamberska T et al have published an interesting pilot study looking at this exact strategy. Their paper entitled Oropharyngeal surfactant can improve initial stabilisation and reduce rescue intubation in infants born below 25 weeks of gestation takes a look at a strategy of instilling 1.5 mL of curosurf directly into the pharynx for infants 22-24 weeks through a catheter inserted 3-4 cm past the lips as a rapid bolus concurrent with a sustained inflation maneuver (SIM) of 25 cm of H2O for 15 seconds. Two more SIMs were allowed of the heart rate remained < 100 after 15 seconds of SIM. The theory here was that the SIM would trigger an aspiration reflex as the pressure in the pharynx increased leading to distribution of surfactant to the lung. The study compared three epochs from January 2011 - December 2012 when SIM was not generally practiced to July 2014 - December 2015 when SIM was obligatory. The actual study group was the period in between when prophylactic surfactant with SIM was practiced for 19 infants. A strength of the study was that resuscitation practices were fairly standard outside of these changes in practice immediately after delivery and the decision to intubate if the FiO2 was persistently above 30% for infants on CPAP. A weakness is the size of the study with only 19 patients receiving this technique being compared to 20 patients before and 20 after that period. Not very big and secondly no blinding was used so when looking at respiratory outcomes one has to be careful to ensure that no bias may have crept in. If the researchers were strongly hoping for an effect might they ignore some of the "rules around intubation" and allow FiO2 to creep a little higher on CPAP as an example? Hard to say but a risk with this type of study. What did they find? The patients in the three epochs were no different from one and other with one potentially important exception. There were higher rates of antenatal steroid use in the study group (95% vs 75 and 80% in the pre and post study epochs). Given the effect of antenatal steroids on reducing respiratory morbidity, this cannot be ignored and written off. Despite this difference it is hard to ignore the difference in endotracheal intubation in the delivery room with only 16% needing this in the study group vs 75 and 55% in the other two time periods. Interestingly, all of the babies intubated in the delivery area received surfactant at the same percentages as above. The need for surfactant in the NICU however was much higher in the study period with 79% receiving a dose in the study group vs 20 and 35% in the pre and post study groups. Other outcomes such as IVH, severe ROP and BPD were looked at with no differences but the sample again was small. What can we take from this? Even taking into account the effect of antenatal steroids, I would surmise that some surfactant did indeed get into the trachea of the infants in the study group. This likely explains the temporary benefit the babies had in the delivery suite. I suspect that there simply was not a big enough dose to fully treat their RDS leading to eventual failure on CPAP and a requirement for intubation. Is all lost though? Not really I think. Imagine you are in a centre where the Neonatologist is not in house and while he/she is called to the delivery they just don't make it in time. The trainee tries to intubate but can't get the tube in. Rather than trying several times and causing significant amounts of airway trauma (as well as trauma to their own self confidence) they could abandon further attempts and try instilling some surfactant into the pharynx and proving a SIM. If it works at all the baby might improve enough to buy some time for them to be stabilized on CPAP allowing time for another intubater to arrive. While I don't think there is enough here to recommend this as an everyday practice there just might be enough to use this when the going gets tough. No doubt a larger study will reveal whether there really is something here to incorporate into the tool chest that we use to save the lives of our smallest infants.
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