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Found 11 results

  1. I know how to bag a baby. At least I think I do. Providing PPV with a bag-valve mask is something that you are taught in NRP and is likely one of the first skills you learned in the NICU. We are told to squeeze the bag at a rate of 40-60 breaths a minute. According to the Laerdal website, the volume of the preterm silicone bag that we typically use is 240 mL. Imagine then that you are wanting to ventilate a baby who is 1 kg. How much should you compress the bag if you wish to delivery 5 mL/kg. Five ml out of a 240 mL bag is not a lot of squeeze is it? Think about that the next time you find yourself squeezing one. You might then say but what about a t-piece resuscitator? A good choice option as well but how much volume are you delivering if you set the initial pressures at 20/5 for example? That would depend on the compliance of the lung of course. The greater the compliance the more volume would go in. Would it be 5 mL, 10 ml or even 2.5 mL based on the initial setting? Hard to say as it really depends on your seal and the compliance of the lung at the pressure you have chosen. If only we had a device that could deliver a preset volume just like on a ventilator with a volume guarantee setting! Why is this holy grail so important? It has been over 30 years since the importance of volutrauma was demonstrated in a rabbit model. Hernandez LA et al published Chest wall restriction limits high airway pressure-induced lung injury in young rabbits. The study used three models to demonstrate the impact of volume as opposed to pressure on injuring the lung of preterm rabbits. Group 1 were rabbit ventilated at pressures of 15/30/45 cm H2O for one hour, group 2 rabbits with a cast around their thorax to limit volume expansion and group 3 sets of excised lungs with no restriction to distension based on the applied pressures. As you might expect, limitation of over distension by the plaster cast led the greatest reduction in injury (measured as microvascular permeability) with the excised lungs being the worst. In doing this study the authors demonstrated the importance of over distension and made the case for controlling volume more than pressure when delivering breaths to avoid excessive tidal volume and resultant lung injury. The “Next Step” Volume Ventilator BVM Perhaps I am becoming a fan of the Edmonton group. In 2015 they published A Novel Prototype Neonatal Resuscitator That Controls Tidal Volume and Ventilation Rate: A Comparative Study of Mask Ventilation in a Newborn Manikin. The device is tablet based and as described, rather than setting a PIP to deliver a Vt, a rate is set along with a volume to be delivered with a peep in this case set at +5. This study compared 5 different methods of delivering PPV to a 1 kg preterm manikin. The first was a standard self inflating bag, the next three different t-piece resuscitators and then the Next Step. For the first four the goal was to deliver a pressure of 20/5 at a rate of 40-60 breaths per minute. A test lung was connected to the manikin such that each device was used for a one minute period at three different levels of compliance (0.5 ml/cmH2O, 1.0 ml/cmH2O and then 2.0 ml/cm H2O representing increasing compliance. The goal of the study was to compare the methods in terms of delivering a volume of 5 mL to this 1 kg model lung. The order in which the devices were used was randomized for the 25 participants in the study who were all certified in NRP and included some Neonatologists. Some Concerning Findings As I said at the beginning, we all like to think we know how to ventilate a newborn with BVM. The results though suggest that as compliance increases our ability to control how much volume we deliver to a lung based on a best guess for pressures needed is lacking. One caveat here is that the pressures set on the t-piece resucitators were unchanged during the 1 minute trials but then again how often during one minute would we change settings from a starting point of 20/5? Vt (mL) 0.5 mL/cmH20 1.0 mL/cmH20 2.0mL/cmH20 Self inflating 11.4 17.6 23.5 Neo-Tee 5.6 11.2 19.3 Neopuff 6.1 10 21.3 Giraffe 5.7 10.9 19.8 Next Step 3.7 4.9 4.5 Without putting in all the confidence intervals I can tell you that the Next Step was the tightest. What you notice immediately (or at least I did) was that no matter what the compliance, the self inflating bag delivers quite an excessive volume even in experienced hands regardless of compliance. At low compliance the t-piece resuscitators do an admirable job as 5-6 ml/kg of delivered Vt is reasonable but as compliance improves the volumes increase substantially. It is worth pointing out that at low compliance the Next Step was unable to deliver the prescribed Vt but knowing that if you had a baby who wasn’t responding to ventilation I would imagine you would then try a setting of 6 ml/kg to compensate much like you would increase the pressure on a typical device. How might these devices do in a 29 week infant for example with better compliance than say a 24 week infant? You can’t help but wonder how many babies are given minutes of excessive Vt after birth during PPV with the traditional pressure limited BVM setup and then down the road how many have BPD in part because of that exposure. I wanted to share this piece as I think volume resuscitation will be the future. This is just a prototype or at least back then it was. Interestingly in terms of satisfaction of use, the Next Step was rated by the participants in the study as being the easiest and most comfortable to use of all the devices studied. Adding this finding to the accuracy of the delivered volume and I think we could have a winner.
  2. Positive pressure ventilation puts infants at risk of developing chronic lung disease (CLD). Chronic lung disease in turn has been linked many times over, as a risk for long term impacts on development. So if one could reduce the amount of positive pressure breaths administered to a neonate over the course of their hospital stay, that should reduce the risk of CLD and by extension developmental impairment. At least that is the theory. Around the start of my career in Neonatology one publication that carried a lot of weight in academic circles was the Randomized Trial of Permissive Hypercapnia in Preterm Infants which randomized 49 surfactant treated infants to either a low (35-45) or high (45-55) PCO2 target with the thought being that allowing for a higher pCO2 should mean that lower settings can be used. Lower settings on a ventilator would lead to less lung damage and therefore less CLD and in turn better outcomes. The study in question did show that the primary outcome was indeed different with almost a 75% reduction in days of ventilation and with that the era of permissive hypercapnia was born. The Cochrane Weigh in In 2001 a systematic review including this and another study concluded that there was insufficient evidence to support the strategy in terms of a benefit to death or chronic lung disease. Despite this lack of evidence and a recommendation from the Cochrane group that permissive hypercapnia be used only in the context of well designed trials the practice persisted and does so to this day in many places. A little lost in this discussion is that while the end point above was not different there may still be a benefit of shorter term ventilation. A modern cohort It would be unwise to ignore at this point that the babies of the late 90s are different that the ones in the current era. Surfactant and antenatal steroid use are much more prevalent now. Ventilation strategies have shifted to volume as opposed to pressure modes in many centres with a shift to early use of modalities such as high frequency ventilation to spare infants the potential harm of either baro or volutrauma. Back in 2015 the results of the PHELBI trial were reported Permissive hypercapnia in extremely low birthweight infants (PHELBI): a randomised controlled multicentre trial. This large trial of 359 patients randomized to a high or low target pCO2 again failed to show any difference in outcomes in terms of the big ones “death or BPD, mortality alone, ROP, or severe IVH”. What was interesting about this study was that they did not pick one unified target for pCO2 but rather set different targets as time went on reflecting that with time HCO3 rises so what matters more is maintaining a minimum pH rather than targeting a pCO2 alone which als0 reflects at least our own centre’s practice. There is a fly in the ointment here though and that is that the control group has a fault (at least in my eyes) Day of life Low Target High Target 1-3 40-50 55-65 4-6 45-55 60-70 7-14 50-60 65-75 In the original studies of permissive hypercapnia the comparison was of a persistent attempt to keep normal pCO2 vs allowing the pCO2 to drift higher. Although I may get some argument on this point, what was done in this study was to compare two permissive hypercapnia ranges to each other. If it is generally accepted that a normal pCO2 is 35-45 mmHg then none of these ranges in the low target were that at all. How did these babies do in the long run? The two year follow-up for this study was published in the last month; Neurodevelopmental outcomes of extremely low birthweight infants randomised to different PCO2 targets: the PHELBI follow-up study. At the risk of sounding repetitive the results of Bayley III developmental testing found no benefit to developmental outcome. So what can we say? There is no difference between two strategies of permissive hypercapnia with one using a higher and the other a lower threshold for pCO2. It doesn’t however address the issue well of whether targeting a normal pCO2 is better or worse although the authors conclude that it is the short term outcomes of shorter number of days on ventilation that may matter the most. The Truth is Out There I want to believe that permissive hypercapnia makes a difference. I have been using the strategy for 15 or so years already and I would like to think it wasn’t poor strategy. I continue to think it makes sense but have to admit that the impact for the average baby is likely not what it once was. Except for the smallest of infants many babies these days born at 27 or more weeks of gestation due to the benefits of antenatal steroids, surfactant and modern ventilation techniques spend few hours to days on the ventilator. Meanwhile the number of factors such chorioamniotitis, early and late onset sepsis and genetic predisposition affect the risks for CLD to a great degree in the modern era. Not that they weren’t at play before but their influence in a period of more gentle ventilation may have a greater impact now. That so many factors contribute to the development of CLD the actual effect of permissive hypercapnia may in fact not be what it once was. What is not disputed though is that the amount of time on a ventilator when needed is less when the strategy is used. Let us not discount the impact of that benefit as ask any parent if that outcome is of importance to them and you will have your answer. So has permissive hypercapnia failed to deliver? The answer in terms of the long term outcomes that hospitals use to benchmark against one and other may be yes. The answer from the perspective of the baby and family and at least this Neonatologist is no.
  3. As the saying goes the devil is in the details. For some years now many centres worldwide have been publishing trials pertaining to high flow nasal cannulae (HFNC) particularly as a weaning strategy for extubation. The appeal is no doubt partly in the simplicity of the system and the perception that it is less invasive than CPAP. Add to this that many centres have found less nasal breakdown with the implementation of HFNC as standard care and you can see where the popularity for this device has come from. This year a contact of mine Dominic Wilkinson@NeonatalEthics on twitter (if you don’t follow him I would advise having a look!) published the following cochrane review, High flow nasal cannula for respiratory support in preterm infants. The review as with most cochrane systematic reviews is complete and comes to a variety of important conclusions based on 6 studies including 934 infants comparing use of HFNC to CPAP. 1. No differences in the primary outcomes of death (typical RR 0.77, 95% CI 0.43 to 1.36; 5 studies, 896 infants) or CLD. 2. After extubation to HFNC no difference in the rate of treatment failure(typical RR 1.21, 95% CI 0.95 to 1.55; 5 studies, 786 infants) or reintubation(typical RR 0.91, 95% CI 0.68 to 1.20; 6 studies, 934 infants). 3. Infants randomised to HFNC had reduced nasal trauma (typical RR 0.64, 95% CI 0.51 to 0.79; typical risk difference (RD) -0.14, 95% CI -0.20 to -0.08; 4 studies, 645 infants). 4. Small reduction in the rate of pneumothorax (typical RR 0.35, 95% CI 0.11 to 1.06; typical RD -0.02, 95% CI -0.03 to -0.00; 5 studies 896 infants) in infants treated with HFNC but the RR crosses one so this may be a trend at best. If one was to do a quick search for the evidence and found this review with these findings it would be very tempting to jump on the bandwagon. Looking at the review a little closer though there is one line that I hope many do not miss and I was happy to see Dominic include it. “Subgroup analysis found no difference in the rate of the primary outcomes between HFNC and CPAP in preterm infants in different gestational age subgroups, though there were only small numbers of extremely preterm and late preterm infants.” In his conclusion he further states: Further evidence is also required for evaluating the safety and efficacy of HFNC in extremely pretermand mildly preterm subgroups, and for comparing different HFNC devices. With so few ELBW infants included and with these infants being at highest risk of mortality and BPD our centre has been reluctant to adopt this mode of respiratory support in the absence of solid evidence that it is equally effective to CPAP in these smallest infants. A big thank you to our Respiratory Therapy Clinical Specialist for harping on this point over the years as the temptation to adopt has been strong as other centres turn to this strategy. Might Not Be So Safe After All Now do not take what I am about to say as a slight against my twitter friend. The evidence to date points to exactly what he and his other coauthors concluded but with the release of an important paper in May by Taka DK et al, I believe caution is needed when it comes to our ELBW infants. High Flow Nasal Cannula Use Is Associated with Increased Morbidity and Length of Hospitalization in Extremely Low Birth Weight Infants This paper adds to the body of literature on the topic as it truly focuses on the outcome of infants < 1000g. While this study is retrospective in nature it does cover a five year period and examines important outcomes of interest to this population. The primary outcome in this case was death or BPD and whether HFNC was used alone or with CPAP, this was more frequent than when CPAP was used alone. Other important findings were the need for multiple and longer courses of ventilation in those who received at least some HFNC. In these times of overburdened health care systems with goals of improving patient flow, it is also worth noting that there was a significant prolongation of length of stay with use of HFNC or HFNC and CPAP. One interesting observation was that the group that fared the worst across the board was the combination of CPAP and HFNC rather than HFNC alone. CPAP (941) HFNC (333) HFNC +/- CPAP (1546) CPAP d (median, IQR) 15(5-28) 7 (1-19) HFNC d (median, IQR) 14(5-25) 13 (6-23) HFNC +/- CPAP 15 (5-28) 14(5-25) 26 (14-39) BPD or death % 50.40% 56.80% 61.50% BPD % 42.20% 52.20% 59.00% Multiple ventiation courses 51.10% 53.10% 64.70% More than 3 vent courses 17.60% 21.00% 29.40% Ventilator d (median, IQR) 18(5-42) 25 (6-52) 30 (10-58) I believe the finding may be explained by the problem inherent with retrospective studies. This is not a study in which patients were randomized to either CPAP, HFNC or CPAP w/HFNC. If that were the case one would expect lung pathologies and severity of illness to even ou,t such that differences between groups might be explained by the difference in treatments. In this study though we are looking though the rearview mirror so to speak. How could we account for the combination being worse than the HFNC alone? I suspect it relates to the severity of lung disease. The babies who were placed on HFNC and did well on it might have had less severe chronic changes. What might be said about those that had the combination? Well, one could postulate that there might be some who were extubated to HFNC and collapsed needing escalation to CPAP and then failing that therapy were reintubated. Another explanation could be those babies who were placed on CPAP after extubation and transitioned before their lungs were ready to HFNC may have failed and lost FRC thereby going back to CPAP and possibly intubation. Exposure in either circumstance to HFNC would therefore put them at risk of further positive pressure ventilation and subsequent further lung injury. The babies who could tolerate transition to HFNC without CPAP might be intermediary in their outcomes (as they were found to be) as they lost FRC but were able to tolerate it but consumed more calories leaving less for growth and repair of damaged tissue leading to prolonged need for support. Either way, the use of HFNC was found to lead to worse outcomes and in the ELBW infant should be avoided as routine practice pending the results of a prospective RCT on the subject. Is it a total ban though? As with many treatments that one should not consider standard of care there may be some situations where there may be benefit. The ELBW infant with nasal breakdown from CPAP that despite excellent nursing and RRT attention continues to demonstrate tissue damage is one patient that could be considered. The cosmetic implications and potential for surgical correction at a later date would be one reason to consider a trial of HFNC but only in the patient that was close to being able to come off CPAP. In the end I believe that if a ELBW infant needs non invasive pressure support then it should be with CPAP but as there saying goes there may be a right time and a place for even this modality.
  4. As I was preparing to settle in tonight I received a question from a reader on my Linkedin page in regards to the use of sustained inflation (SI) in our units. We don't use it and I think the reasons behind it might be of interest to others. The concept of SI is that by providing a high opening pressure of 20 - 30 cm H2O for anywhere from 5 to 15 seconds one may be able to open the "stiff" lung of a preterm infant with RDS and establish an adequate functional residual capacity. Once the lung is open, it may be possible in theory to keep it open with ongoing peep at a more traditional level of 5 - 8 cm of H20. The concept was tested 25 years ago by Vyas et al in their article Physiologic responses to prolonged and slow-rise inflation in the resuscitation of the asphyxiated newborn infant. In this study, 9 newborn infants were given a relatively short 5 second sustained inflation and led to earlier and larger lung volumes with good establishment of FRC. Like many trials in Neonatology though sceptics abound and here we are 25 years later still discussing the merits of this approach. As I have a warm place in my heart for the place that started my professional career whenever I come across a paper published by former colleagues I take a closer look. Such is the case with a systematic review on sustained inflation by Schmolzer et al. The inclusion criteria were studies of infants born at <33 weeks. Their article provides a wonderful assessment of the state of the literature on the topic and I would encourage you to have a look at it if you would like a good reference to keep around on the topic. What it comes down to though is that there are really only four randomized human studies using the technique and in truth they are fairly heterogeneous in their design. They vary in the length of time an SI was performed (5 - 20 seconds), the pressures used (20 - 30 cm H2O), single or multiple SIs and lastly amount of oxygen utilized being 21 - 100%. In fact three of the four studies used either 100% or in one case 50% FiO2 when providing such treatments. What Did They Show? This is where things get interesting. SI works in the short term by reducing the likelihood that an infant will need mechanical ventilation at 72 hours with a number needed to treat of only 10! In medicine we normally would embrace such results but sadly the results do not translate into long term benefits as the rate of BPD, mortality and the combined outcome do not remain significant. Interestingly, the incidence of a symptomatic PDA needing treatment with either a medical or surgical approach had a number needed to harm of 11; an equally impressive number but one that gives reason for concern. As the authors speculate, the increased rate of PDA may be in fact related to the good job that the SI does in this early phase. By establishing an open lung and at an earlier time point it may well be that there is an accentuation in the relaxation of the pulmonary vasculature and this leads to a left to right shunt that by being hemodynamically significant helps to stent the ductus open at a time when it might otherwise be tending to close. This outcome in and of itself raises concern in my mind and is the first reason to give me reason to pause before adopting this practice. Any other concerns? Although non-significant there was a trend towards increased rates of IVH in the groups randomized to SI. There is real biologic plausibility here. During an SI the increased positive pressure in the chest could well simulate a similar effect to a pneumothorax and impede the passive drainage of blood from the head into the thorax. In particular, longer durations and/or frequent SIs could increase such risk. Given the heterogeneous nature of these studies it is difficult to know if they all had been similar in providing multiple SIs could we have seen this cross over to significant? I believe the biggest concern in all of this though is that I would have a very hard time applying the results of these studies to our patient population. The systematic review addresses the question about whether SI is better than IPPV as a lung recruitment strategy in the preterm infant with respiratory distress. I have to say though we have moved beyond IPPV as an initial strategy in favour of placement of CPAP on the infant directly after birth. The real question in my mind is whether providing brief periods of SI followed by CPAP of +6 to +8 is better than placement on CPAP alone as a first strategy to establish good lung volumes. If I am to be swayed by the use of SI someone needs to do this study first. The possibility of increasing the number of hemodynamically significant PDAs and potentially worsening IVH without any clear reduction in BPD is definitely placing me firmly in the camp of favouring the CPAP approach. Having said all that, the work by the Edmonton group is important and gives everyone a glimpse into what the current landscape is for research in this field and opens the door for their group or another to answer my questions and any others that may emerge as this strategy will no doubt be discussed for years to come.
  5. Ask almost anyone who has worked in the field of Neonatology for some time and they will tell you that babies are not as sick as they once were. We can give a lot of credit to better antenatal steroid use, maternal nutrition and general management during pregnancy. Additionally, after birth we now rush to place infants on CPAP and achieve adequate expansion of the lungs which in many cases staves off intubation. The downside to our success though is that the opportunities to provide positive pressure ventilation (PPV) and moreover intubation are becoming less and less. How then do we perform when we are asked to do such procedures on an infrequent basis? The answer as you might expect is not that well. Dr. Schmolzer et al studied the ability of people to keep a good seal and found a 29% leak on average with as high as 63% in one patient. As this was a study in which people were being observed one might think the Hawthorne Effect might artificially decrease the percentage leak compared to real world scenarios when you know you aren't being watched. What is the cause of the leak? Leaks most commonly occur on either side of the nasolabial folds. Although at least in my experience we educate trainees about this issue it remains a problem. I would also speculate that at the times when we need to be at our best during an advanced resuscitation involving chest compressions we may well function at our worst. This is the effect of the adrenalin rushing through our system as our sympathetic system turns into overdrive. The question therefore is one of getting around human error in particular when we need to minimize such inefficiency the most. The Solution? If the masks are prone to leaking and with it the ability to properly ventilate compromised, how could we minimize such human error. The answer may lie in what I consider to be an ingenious way to apply a mask. The concept and it is just that at the moment is to use suction to apply the mask to the face without risk of leak. Lorenz L et al have just published a proof of concept study utilizing a mannequin with a "seal skin" layer applied to the face to simulate human skin. The article is entitled A new suction mask to reduce leak during neonatal resuscitation: a manikin study. In this study, the mask was applied to the face of the mannequin and 100 cm H2O pressure was applied through a side port on the mask. There is an inner and outer ring such that the internal 41 mm diameter mask is surrounded by a double wall in which the suction is applied to the space between the two walls leading to the mask seating itself firmly against the face. The authors then studied the amount of leak found when using a Neopuff set to deliver 40 - 60 breaths per minute at pressures of 25/5. For this study 60 courses were tested. How did it do compared to PPV through a traditional mask? As you might expect (since you can feel my excitement!) it did very well. The average leaks using a conventional approach were quite good at 12.1% but the suction mask was only 0.7% leak. Importantly the ranges were quite different. PPV through a conventional mask had a range of 0.6 - 39% leak while with the suction version it was 0.2 - 4.6%. These results were statistically different. What does the future hold? As mentioned this study is what one would consider a proof of concept study. We do not know how this would fare in the real world and that of course is the next step. In terms of harm, the authors did note that when applied to the forearm of an adult it caused some mild redness from the suction that vanished quickly on breaking of the seal but we do not know if there could be greater harm in a newborn in particular one who is quite small. Such testing will be needed as part of any further study. Having said that I think this rethink of the mask for PPV could be transformative to those who perform neonatal resuscitation infrequently. If this mask is found not only to be effective in a clinical trial but safe as well I would suggest a change to this type of mask could quite literally be life saving. Placed in the hands of those who are inexperienced in keeping a seal, PPV would become much more effective and in particular for rural sites the infants being transported in much more stable than some are at present. Keep your eyes peeled for future work using this mask. Something tells me if it proves to be efficacious outside of a seal skin covered mannequin, your toolkit for providing NRP may be in for a change.
  6. I will admit it. I resist change at times just like many others. This may come as a surprise to some of you who have worked with me and accused me of bringing too much change at times to the units. The truth though is that when one understands something and is enthusiastic about implementation the change does not seem so difficult. When it isn't your idea though we may find ourselves a little uneasy about adopting this unfamiliar practice. Such has been my experience with nasal HFOV. It is a strategy that has been around for over five years but has seen slow adoption among centres in Canada and has trickled into practice in Winnipeg on a few occasions. In each occasion when I have been asked about either continuing or perhaps starting this therapy I have shrugged my shoulders and confessed my inexperience with the modality. Sure I have used HFOV through an ETT but through prongs or a mask?! How would it work? Could it cause harm? What would the actual indications be? How would our in house physicians and NNPs respond to abnormal gases overnight even if I felt comfortable with using it? These sorts of questions have led to virtual inertia in my acceptance of the strategy. Before I go on it would be good to see an example of how it is set up. The MedinCNO device is capable of delivering such non-invasive HFOV and can be seen in this short video. One could use the strategy either prophylactically to extubate an infant or as rescue to prevent reintubation if trials of either CPAP or NIPPV were unsuccessful. HFOV is known to be very effective at clearing CO2 when used through an ETT so perhaps nasal application could also lower pCO2 and achieve a similar effect. This was tested using a neonatal lung simulator by Mukeji A et al Nasal high-frequency oscillation for lung carbon dioxide clearance in the newborn. In this study CO2 was introduced into the manequin and the amount of exhaled CO2 determined while on CPAP, NIPPV and nasal HFOV. Interestingly during CPAP no exhaled CO2 could be detected while CO2 clearance occurred during NIPPV and nasal HFOV although it was three-fold greater with HFOV. In theory then CO2 clearance would appear to be better so in the case of ventilatory failure as evidenced by CO2 retention this modality would seem to win out. Clinical Evidence for Use There is one RCT in term infants with TTN to support the practice while the rest are unblinded case series with no controls. Four Canadian NICUs recently described their experience however using a retrospective analysis. Included were 79 instances of HFOV distributed as follows; 73% utilized as rescue from another mode and in 27% used as the primary mode for extubation. The outcomes are shown in the table: In 45% of cases the patients needed intubation after first trialing CPAP or NIPPV while in 33% of cases following extubation the infants needed replacement of the endotracheal tube. The numbers here are small so it is difficult to truly compare them to other studies with confidence but reintubation rates of 40-44% have been noted recently when using NIPPV or CPAP so the numbers are at least consistent. One aspect though that caught my eye was the duration of use for HFOV across these 79 patients. The median use was 57 hours with the longest duration being just over 400 hours. It would seem that the use of this modality for the most part is as a bridge to something else. The median duration of 2.5 days is much shorter than the weeks that some of our smallest infants remain on CPAP/NIPPV for. Whether for rescue or prophylaxis this is not a long term option. Another point worth noting though is the question of whether it is the pressure or oscillatory wave that is leading to success. As the authors note, there were a wide range in applications of MAP, delta P and frequency. MAP ranges from 8 - 24 cm H2O while frequency from 6 - 14 hz and amplitude varied widely depending on the device used but was as high as 100%. While high MAP has been used invasively though an ETT I can't help but wonder if in some cases the real benefit was the high MAP. What would happen for example if the centres had simply raised the CPAP to 10, 12 or even higher? In the end it would seem that in principal it is an effective therapy that may be able to remove CO2 more efficiently than the other modes. What we don't have are RCTs in the smallest babies comparing HFOV to NIPPV or CPAP with adequate power to detect differences. I suspect these will come soon enough but what do we do in the meantime? The main reservation I have has to do with safety. We truly have little if any data on this without proper trials to ease such worry. When a patient is in front of us though and is failing CPAP or NIPPV what are we to do? Should we intubate or trial this modality based on the evidence thus far? I might be tempted to trial HFOV in this circumstance but as with any new therapy we need education for all staff. Everyone caring for our infants need to understand what they are using and how to respond based on clinical findings. This is the real issue with safety that I see and until such time that we have widespread education across RRT, nursing and medicine I would suggest we use this with trepidation. This is not a rejection of the modality in the least but rather a call to come together as a team and see how implement this in such a way that will provide direction to caregivers, provide a consistent approach with respect to length of use, indications and when to change direction entirely. Time to call a meeting of the minds I think.
  7. until
    From the website: The 13th European Conference on Pediatric and Neonatal Mechanical Ventilation will again be in Montreux (Switzerland), which will continue to provide the unique and ideal environment for our meeting. As in previous year, thematic sessions include lecturers by key experts and wellknown speakers on various topics related to ventilation and respiratory failure in newborns and children. With the previous very positive and exciting experience integrating nursing in the educational program. http://www.epnv-montreux.org/
  8. One of my very early posts on this blog pertained to my fascination with an Israeli strategy of monitoring end tidal CO2 in place of drawing blood gases. Please see A Strategy to Minimize Blood Sampling in ventilated premature and term infants. The gist of this strategy is that by sampling distal CO2 measurements near the carina you obtain a non diluted sample of CO2 as compared to the traditional proximal end tidal measurement. The authors have shown this to be highly accurate compared to comparable arterial samples during both conventional and high frequency oscilatory ventilation. This month the same group published a follow-up study that has me excited again about this technological approach. The paper is entitled Impact of Continuous Capnography in Ventilated Neonates: A Randomized, Multicenter Study. In this multicentre study 55 infants were ventilated through double lumen endotracheal tubes. The first group of 25 were randomized to an open group in which the continuous CO2 measurement was available to clinicians to base ventilator management on. The second group had these values recorded but the treating physicians were blind and based ventilatory changes on arterial blood gas sampling. The primary outcome was based on the percentage of time pCO2 was kept between 30 - 60 with the goal range for permissive hypercapnea being 45 - 55. The Results "Compared with infants in the masked group, those in the monitored group had significantly (P = .03) less time with an unsafe dETCO2 level (high: 3.8% vs 8.8% or low: 3.8% vs 8.9%). The prevalence of intraventricular hemorrhage or periventricular leukomalacia rate was lower in the monitored group (P = .02) and was significantly (P < .05) associated with the independent factors dETCO2 monitoring and gestational age." The same held true for the blood gas values with statistically significant benefits in terms of keeping CO2 within the predefined safe range. My Interpretation The findings make a great deal of sense. Sampling continuously and adjusting ventilation in real time (assuming a strong correlation between EtCO2 and blood gases) makes sense. Blood gases done even every four hours can not compare to having results available continuously. As such I tend to believe the findings of better accuracy. Although the incidence of IVH and PVL are part of the secondary outcomes there is significant biologic plausability to these findings. We know that cerebral blood flow is very sensitive to PCO2 with low values causing cerebral vasoconstriction and high values dilation of these same vessels. Furthermore having wide swings in CO2 could lead to periods of ischemia and then significant reperfusion with resultant injury. Finding that these two outcomes are increased with intermittent sampling therefore is plausible and deserving of further study. Challenges That Need to Be Addressed Since the publications by the same group showing the accuracy of this method of sampling CO2 we have tried this strategy for several infants. In short, it works and is very accurate. We have been able to avoid many blood gases along the way but there remains a significant challenge with avoiding blockage of the second port for sampling. Furthermore, secretions if getting past the end of the port and into the microstream sampling device can damage the analyzer such that we have only one left functioning in our units. As eager as I am to roll this out as a change in practice we need to address these technical issues but once accomplished this may truly have an impact as a cerebral protective strategy for the preterm infant and with time and further long term outcomes available offer a meaningful way of reducing disability in this population.
  9. A one day study day covering hot topics in Neonatal ventilation Organised by the Evelina London Children's Hospital and King's College London Details: http://www.guysandstthomasevents.co.uk/paediatrics-training/neonatal-ventilation-updates-hot-topics-and-workshops/ A4 flyer - Neonatal Ventilation 2014 - low res.pdf
  10. This article was recently published in ADC, a systematic review about volume-targeted vs pressure-limited ventilation. The message is that volume-targeting has advantages, as this mode is associated with... Personal reflection: finally there is enough research data to show that volume-targeting seems to be superior over pressure-limited ventilation there are a lot of less good research out there; only 18 of 59 potentially relevant studies were included in this review the authors of this systematic review are not the "usual suspects" (guess whom!) - but a research group in China - the country quickly climbing the research ladder Link to the article in full-text: http://fn.bmj.com/content/99/2/F158.full
  11. Go to www.neonatalpneumologynaples.it and check the program !! We welcome you to join a high rank scientific meeting in a world class tourist destination Latest updates in Resuscitation Ventilation Lung ultrasound ... and much more !! Naples, Italy APRIL 11th and 12th, 2014
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