It is hard to believe but it has been almost 3 years since I wrote a piece entitled A 200 year old invention that remains king of all tech in newborn resuscitation. In the post I shared a recent story of a situation in which the EKG leads told a different story that what our ears and fingers would want us to believe. The concept of the piece was that in the setting of pulseless electrical activity (where there is electrical conductance in the myocardium but lack of contraction leaves no blood flow to the body) one could pick up a signal from the EKG leads when there is in fact no pulse or perfusion to vital organs. This single experience led me to postulate that this situation may be more common than we think and the application of EKG leads routinely could lead to errors in decision making during resuscitation of the newborn. It is easy to see how that could occur when you think about the racing pulses of our own in such situations and once chest compressions start one might watch the monitor and forget when they see a heart rate of 70 BPM to check for a corresponding pulse or listen with the stethoscope. I could see for example someone stopping chest compressions and continuing to provide BVM ventilation despite no palpable pulse when they see the QRS complex clearly on the monitor. I didn’t really have much evidence to support this concern but perhaps there is a little more to present now.
A Crafty Animal Study Provides The Evidence
I haven’t presented many animal studies but this one is fairly simple and serves to illustrate the concern in a research model. For those of you who haven’t done animal research, my apologies in advance as you read what happened to this group of piglets. Although it may sound awful, the study has demonstrated that the concern I and others have has is real.
For this study 54 newborn piglets (equivalent to 36-38 weeks GA in humans) were anesthetized and had a flow sensor surgically placed around the carotid artery. ECG leads were placed as well and then after achieving stabilization, hypoxia was induced with an FiO2 of 0.1 and then asphyxia by disconnecting the ventilator and clamping the ETT. By having a flow probe around the carotid artery the researchers were able to determine the point of no cardiac output and simultaneously monitor for electrical activity via the EKG leads. Auscultation for heart sounds was performed as well.
The results essentially confirm why I have been concerned with an over reliance on EKG leads.
Of the 57 piglets, 14 had asystole and no carotid flow but in 23 there was still a heart rate present on the EKG with no detectable carotid flow. This yields a sensitivity of only 37%. Moreover, the overall accuracy of the ECG was only 56%.
Meanwhile the stethoscope which I have referred to previously as the “king” in these situations had 100% sensitivity so remains deserving of that title.
What do we do with such information?
I think the results give us reason to pause and remember that faster isn’t always better. Previous research has shown that signal acquisition with EKG leads is faster than with oximetry. While a low heart rate detected quickly is helpful to know what the state of the infant is and begin the NRP pathway, we simply can’t rely on the EKG to tell us the whole story. We work in interdisciplinary teams and need to support one another in resuscitations and provide the team with the necessary information to perform well. The next time you are in such a situation remember that the EKG is only one part of the story and that auscultation for heart sounds and palpation of the umbilical cord for pulsation are necessary steps to demonstrate conclusively that you don’t just have a rhythm but a perfusing one.
I would like to thank the Edmonton group for continuing to put out such important work in the field of resuscitation!
Hi, my name is Diane Schultz and Michael has asked me to write a series of posts on his blog about Kangaroo Care (KC). Seeing as I am one of the Champions (they call you that, but sometimes the word begins with a B) for KC in my unit, I was thrilled. I thought I would begin with an introduction as to why I want to write about this.
I have been a Neonatal Nurse for 29 years working in the NICU at St. Boniface Hospital in Winnipeg. I felt that I had always given good care to the families but did not really make connections with them.
I was fortunate enough to meet Dr. Susie Ludington about 10 years ago at an Academy of Neonatal Nursing conference. She was a general session presenter and was speaking about Kangaroo Care. The first thing she said was “My goal is Kangaroo Care 24/7”. All I could think of was WTF!? I would have to listen to this Nutbar for an hour? Our unit had been doing KC for years but only occasionally and usually the parent would ask for it, we certainly did not promote it or do it with our more fragile infants.
After listening to Dr. Ludington present, my world changed. What she said hit a cord; she presented benefit after benefit with rationale and evidence that made complete sense to me. I felt guilty I had not been doing this at work and guilty that I had not held my own daughters this way. I am now lucky to be able to call Dr. Ludington a friend, and know she has changed my life.
Now, there is a lot of evidence out there touting the benefits of KC, but the real way to understand and believe in it is to do it. KC creates its own evidence. Every time I bring out a medically fragile infant to be held in KC, I know that this is the right place for that infant to be: with their parent being held. You can see the relaxation on all of their faces (decreasing cortisol), the infant is able to go into a deep sleep (promotes brain maturation), and the family is able to connect in the best way possible. I feel KC is as important as anything else we do at the bedside and is an extremely necessary therapy.
Promoting KC in my unit has benefited me at so many levels; I believe it has actually saved my career and given me a focus that I didn’t have before. You can’t help but make connections with your families, and these families are able to make connections with their little ones. KC is also a very important part of Family Integrated Care, as this is something that the family can contribute to their child’s care.
I also couldn’t be more proud of my unit; the staff I have the pleasure to work with are some of the best health care professionals around. They make every effort to bring our fragile infants out for KC and it has become part of our culture in our NICU. KC happens in our unit with almost all of our infants, the only exceptions being actively cooling babies and infants with chest tubes. We have also created a Standard Work Protocol so all medically fragile infants come out the safest way possible without creating extra stress on the infant or family.
In my series of posts I will present the many benefits of KC for infants and their families and share some of my experiences. I hope you will be able to take something away from this, begin to try KC in your own unit, and create your own evidence.
We hope to provide education through links to publications and videos demonstrating the benefits of adopting POCUS! Less ionizing radiation and enhanced diagnostic accuracy are just two of the benefits of using such techniques. Videos demonstrating and discussing this technique can be found on the Point of Care Neonatal Ultrasound Playlist on my Youtube channel
Background
Use of point of care ultrasound has expanded over the last decades particularly in intensive care to the point that it is now readily available for use by the clinical care practitioners in this setting (1). Today clinicians are using ultrasound at the bedside to assist in the evaluation of physiological abnormalities in a number of body systems. Ultrasound has been used to image body organs for over 50 years (2). It is currently the most widely used imaging modality in medicine. Advantages are that ultrasound is portable, free of radiation risk and relatively inexpensive compared to other diagnostic modalities like magnetic resonance and computed tomography (3). The main limitation when considering this for use by NICU clinicians is that it requires advanced training. In addition, when compared to traditional x-ray, ultrasound has limited penetration to air and bones and therefore structures deeper to them cannot be well assessed (4).
Indications:
There are three general indications for ultrasound in the neonatal setting:
1) Anatomic assessment of static organs such as the brain, lungs, liver, kidney and spleen to evaluate for anomalies, hemorrhage, space occupying lesions and abnormal fluid collections.
2) Dynamic assessment of moving organs, such as the heart, lungs, intestine, and the vascular system to evaluate blood flow and physiologic processes.
3) Locating vessels for cannulation and determining the position of catheter tips.
Anatomic ultrasound assessment of static organs should be provided by a trained radiologist. Dynamic ultrasound assessment can be performed by a trained neonatal clinician who understands the clinical details of his or her patients and is familiar with the underlying pathophysiologic mechanisms (5). Table 1 shows different applications performed by a trained clinician.
Point of care lung ultrasound:
In the last 10 years, research studies have shown that lung ultrasound (LUS) is an accurate, non-invasive method for predicting ventilatory failure and offers advantages over traditional chest radiography (6). LUS can accurately and reliably diagnose transient tachypnea of the newborn (TTN) and has a great value in differentiating TTN from respiratory distress syndrome (RDS) (7). Additionally, many of the other common pulmonary and pleural diseases in neonates display specific findings on LUS which can be useful in the differential diagnosis (8).
We developed a screening model of bedside lung ultrasound assessment for infants requiring respiratory support5. Like any other diagnostic technique it should be only used in integration with the clinical assessment and interpreted according to the clinical presentation of the individual patient while considering particular limitations of this modality.
Point of care intestinal ultrasound:
Necrotising enterocolitis is a serious disorder in infants and commonly associated with complications like short bowel syndrome and total parenteral nutrition related issues. The reported mortality is up to 40%, so early diagnosis and management are essential (9). The radiographic diagnosis by XR after clinical suspicion is still the standard in most centers. The main issue with radiograph is being limited to 3 main findings, pneumatosis intestinalis (PI), portal vein gases (PVG), and perforation, and radiograph diagnosis of PI and PVG is sometimes a challenge with low sensitivity and wide range of inter-observer variability. There has been increasing evidence that with real-time ultrasound, PI and PVG can be better detected than with x-ray (10). Ultrasound is able to assess the bowel wall directly and detect bowel wall thickening or thinning, reduced peristalsis or abnormal bowel wall perfusion by color Doppler. Peritoneal fluid, both intraluminal and extra luminal is also visible (11,12). This can be performed in any suspected case with compromised intestinal performance like intestinal obstruction or ischemia and not only in cases with suspected NEC.
Table 1: different applications performed by either professional sonographer (radiologist or cardiologist) or a trained clinician
Cranial ultrasound
emergency assessment of suspected hemorrhage
Doppler assessment of cerebral arteries in cases hemodynamic instability e.g. PDA
Intestinal ultrasound Urgent evaluation of suspected necrotizing entercolitis, intestinal ischemia
Lung ultrasound New emerging modality for assessment of common neonatal lung diseases, e.g. RDS, TTN, meconium, pneumothorax, pleural effusions.
Focused heart ultrasound Assessment of specific neonatal hemodynamics issues
Vascular assessment Blood flow by Doppler for assessment of resistance or shunting of blood through arteriovenous malformation or PDA
Interventional POCUS Central line placement, lumber puncture, bladder tapping for urine sample. Peritoneal and pericardial tap of significant effusions
References:
1. Evans N, Gournay V, Cabanas F, et al. Point-of-care ultrasound in the neonatal intensive care unit: international perspectives. Semin Fetal Neonatal Med. 2011;16(1):61-68. doi:10.1016/j.siny.2010.06.005.
2. Pereda M a., Chavez M a., Hooper-Miele CC, et al. Lung ultrasound for the diagnosis of Pneumonia in Children: A Meta-analysis. Pediatrics. 2015;135(4):714-722. doi:10.1542/peds.2014-2833.
3. Escourrou G, De Luca D. Lung ultrasound decreased radiation exposure in preterm infants in a neonatal intensive care unit. Acta Paediatr. 2016:n/a-n/a. doi:10.1111/apa.13369.
4. Volpicelli G, Elbarbary M, Blaivas M, et al. International evidence-based recommendations for point-of-care lung ultrasound. Intensive Care Med. 2012;38(4):577-591. doi:10.1007/s00134-012-2513-4.
5. Elsayed Y, Abdelmawla M, Narvey M. A model of integrated lung and focused heart ultrasound as a new screening examination in infants at risk of respiratory or hemodynamic compromise. 2017;6(1):1-14. doi:10.7363/060131.
6. Xirouchaki N, Magkanas E, Vaporidi K, et al. Lung ultrasound in critically ill patients: comparison with bedside chest radiography. Intensive Care Med. 2011;37(9):1488-1493. doi:10.1007/s00134-011-2317-y.
7. Liu J, Cao H-Y, Wang X-L, Xiao L-J. The significance and the necessity of routinely performing lung ultrasound in the neonatal intensive care units. J Matern Neonatal Med. 2016;7058(March):1-6. doi:10.3109/14767058.2016.1152577.
8. Copetti R, Cattarossi L. Lung Ultrasound in Newborns, Infants, and Children. 2011:241-245. doi:10.1007/978-3-642-21247-5.
9. Dilli D, Suna Oğuz S, Erol R, Ozkan-Ulu H, Dumanlı H, Dilmen U. Does abdominal sonography provide additional information over abdominal plain radiography for diagnosis of necrotizing enterocolitis in neonates? Pediatr Surg Int. 2011;27(3):321-327. doi:10.1007/s00383-010-2737-8.
10. Bohnhorst B. Usefulness of abdominal ultrasound in diagnosing necrotising enterocolitis. Arch Dis Child Fetal Neonatal Ed. 2013;98:F445-50. doi:10.1136/archdischild-2012-302848.
11. Gale HI, Gee MS, Westra SJ, Nimkin K. Abdominal ultrasonography of the pediatric gastrointestinal tract. World J Radiol. 2016;8(7):656. doi:10.4329/wjr.v8.i7.656.
12. Kim H-Y, Kim I-O, Kim WS, Kang GH. Bowel sonography in sepsis with pathological correlation: an experimental study. Pediatr Radiol. 2011;41(2):237-243. doi:10.1007/s00247-010-1806-4.
Welcome to the home page for our Integrated Evaluation of Hemodynamics program at the University of Manitoba. This program began in Winnipeg, Manitoba, Canada in 2014 and has been growing ever since.
What is considered normal hemodynamics?
1. Intact or normal hemodynamics implies blood flow that provides adequate oxygen and nutrient delivery to the tissues.
2. Blood flow varies with vascular resistance and cardiac function; both may be reflected in blood pressure(2). Normal cardiovascular dynamics should be considered within the context of global hemodynamic function, with the aim of achieving normal oxygen delivery and end organ performance
3. The current routine assessment of hemodynamics in sick preterm and term infants is based on incomplete information. We have addressed this by adopting an approach utilizing objective techniques, namely integrating targeted neonatal echocardiography (TNE) with near-infrared spectroscopy (NIRS). Implementation of these techniques requires an individual with the requisite TNE training, preferably in an accredited program, who also has a good understanding of perinatal and neonatal cardiovascular, respiratory, and other specific end organ physiology.
Why are premature infants more susceptible to cardiovascular compromise?
Hemodynamic compromise in the early neonatal period is common and may lead to unfavorable neurodevelopmental outcome4. A thorough understanding of the physiology of the cardiovascular system in the preterm infants, influence of antenatal factors, and postnatal adaptation is essential for the management of these infants during the early critical phase5. The impact of the various ventilator modes, the presence of a patent ductus arteriosus (PDA), and systemic inflammation all may affect the hemodynamics6. The poor clinical indicators of systemic perfusion and the relative insensitivity of conventional echocardiographic techniques in assessing myocardial contractility mean that monitoring of the hemodynamics of the preterm infant remains a challenge7.
What is integrated hemodynamics in neonatal care?
Integrated hemodynamics focuses on how to interpret multiple tools of hemodynamics evaluation in sick infants (TNE, clinical details, NIRS, organ specific ultrasound) and the art of formulating a pathophysiologic relevant medical recommendation.
Main objectives of applying Targeted Neonatal Echocardiography and Evaluation of Neonatal hemodynamics
Optimise care of infants with hemodynamic compromise to prevent progression into late irreversible stages of shock (Hypoxia)
Decrease overall PDA related complications (Hypoxemia and hypoxia)
Optimize care of infants with hypoxemic respiratory failure (HRF)
Decrease the incidence of progression of infants with hypoxemic respiratory failure and shock to end organ dysfunction
Objective of the program
Orientation to the hemodynamics concepts and basics
Orientation to the 3 level of the pathophysiologic approach to hemodynamics:
Level one: Relying on blood pressure trends (systole, diastole, and pulse pressure) and waveforms with other clinical parameters (all NICU practitioners)
Level one plus (advanced monitoring): Relying on blood pressure trend and near infrared spectroscopy (NIRS) for assessment of hemodynamics and oxygen extraction (optional to NICU practitioners)
Level two (TNE approach): Relying on both clinical parameters and TNE for objective assessment of cardiac output, extra and intra cardiac shunts, systemic and pulmonary vascular resistance. (Neonatologist trained on TNE)
Level three (integrated evaluation of hemodynamics): integrating blood pressure trends, TNE and NIRS for assessment of oxygen delivery, specific end organ oxygen consumption and the degree of compensation (comprehensive hemodynamic approach)
Understanding the rationale for the measurements and the specific values for each disease, and recognize limitations of the 3 models
To see research that we have done in the area of Integrated Hemodynamics please see our publication list that can be found here.
To access our video series providing examples of TNE and presentations on the use of hemodynamics in clinical application please see our Youtube channel playlist “Integrated Neonatal Hemodynamics”
References
Wolff CB. Normal cardiac output, oxygen delivery and oxygen extraction. Adv Exp Med Biol. 2008;599:169-182. doi:10.1007/978-0-387-71764-7-23.
Azhan A, Wong FY. Challenges in understanding the impact of blood pressure management on cerebral oxygenation in the preterm brain. Front Physiol. 2012;3 DEC(December):1-8. doi:10.3389/fphys.2012.00471.
de Boode WP. Clinical monitoring of systemic hemodynamics in critically ill newborns. Early Hum Dev. 2010;86(3):137-141. doi:10.1016/j.earlhumdev.2010.01.031.
Sehgal A. Haemodynamically unstable preterm infant: an unresolved management conundrum. Eur J Pediatr. 2011;170(10):1237-1245. doi:10.1007/s00431-011-1435-4.
Vutskits L. Cerebral blood flow in the neonate. Paediatr Anaesth. 2014;24(2):22-29. doi:10.1111/pan.12307.
Noori S, Stavroudis T a, Seri I. Systemic and cerebral hemodynamics during the transitional period after premature birth. Clin Perinatol. 2009;36(4):723-36, v. doi:10.1016/j.clp.2009.07.015.
Elsayed YN, Amer R, Seshia MM. The impact of integrated evaluation of hemodynamics using targeted neonatal echocardiography with indices of tissue oxygenation: a new approach. J Perinatol. 2017. doi:10.1038/jp.2016.257.
