Sixteen term newborn mixed breed piglets (1–3 days of age, weighing 2.0 ± 0.4 kg) were obtained on the day of experimentation from the University Swine Research Technology Centre. The objectives of this study were to (i) evaluate the accuracy of Doppler-US using different examination modes and transducer positioning and (ii) evaluate its accuracy during progressive bradycardia, using a porcine model of neonatal asphyxia. However, the current evidence for its use for HR assessment during neonatal resuscitation remains scarce. Furthermore, Doppler-US has previously been described to assess HR in the Neonatal Intensive Care Unit and the delivery room ( 14– 17). It is routinely used to assess fetal HR, among other fetal cardiac function parameters, throughout pregnancy and in the delivery room ( 13, 14). It uses high frequency sound waves to detect blood flow based on differences in the frequency of emitted and reflected sound waves ( 12). While ECG and PO can measure HR accurately, both are limited by delays in time needed to display first HR values among other issues related to reliability, accuracy, quickness, or ease of use ( 10, 11).ĭoppler ultrasound (Doppler-US) is routinely used for diagnostic and clinical decision making throughout pregnancy and during labor. However, studies have reported that HR is underestimated by an average of 14 beats per minutes (bpm) during auscultation and 21 bpm during umbilical cord palpation when compared to HR obtained by electrocardiography (ECG) ( 8, 9). Auscultation, umbilical cord palpation, electrocardiography (ECG), and pulse oximetry (PO) are recommended by the current neonatal resuscitations guidelines for HR assessment at birth ( 6, 7). During asphyxia, assessment of HR must be accurate to avoid either overestimation or underestimation, which could either lead to delayed or inappropriate interventions ( 4, 5). Assessment of HR is used to determine the timing, type and efficacy of respiratory support and neonatal resuscitation interventions ( 2, 3). Heart rate (HR) is therefore the most important parameter to assess a newborn infant's clinical status at birth. Doppler-US can be positioned along the sternum and use either AV or PV mode for accurate assessments in a piglet model of neonatal asphyxia.Īsphyxia at birth is the most common reason that newborn infants fail to make a successful fetal-to-neonatal transition, as it can depress myocardial function and induce bradycardia, leading to asystole (cardiac arrest) ( 1). Additionally, motion artifacts produced false peaks and peak size was seen to decrease as bradycardia progressed.Ĭonclusions: HR assessment using Doppler-US during asphyxia is accurate but has limitations and must be further evaluated prior to clinical use. Study III: Bland-Altman analysis revealed a mean difference (95% limits of agreement) between Doppler-US and ECG HR of 1.5 (−16 to 19) bpm. Study II: The mean (SD) Doppler-US HR using AV and PV modes also showed no difference when compared to ECG HR. Measurements and Main Results: Study I: Mean (SD) Doppler-US HR at position A, B, and C showed no difference when compared to ECG HR. Comparisons were made between Doppler-US and the clinical gold standard for HR assessments, electrocardiography (ECG). Interventions: Study I: Doppler-US (USCOM ® 1A) HR was assessed on upper (A), middle (B), and lower (C) third of the sternum study II: Doppler-US HR was assessed using AV and PV examination modes study III: HR was assessed during asphyxia. Study I evaluated optimal transducer position, Study II compared aortic (AV) and pulmonary (PV) examination modes, and Study III examined accuracy during asphyxia, for HR assessment. We aimed to evaluate accuracy and optimal use of Doppler-US for HR assessments during neonatal asphyxia in a pre-clinical model.ĭesign: HR assessments were performed in 16 term newborn piglets that were anesthetized, intubated, and instrumented. While existing HR assessment methods have several limitations, the Doppler ultrasound (Doppler-US) might be a promising alternative. Accurate heart rate (HR) assessment guides resuscitation interventions, thereby reducing morbidities and mortality. Objectives: Approximately 10% of newborn infants require resuscitation at birth. 3Women and Children's Health Research Institute (WCHRI), University of Alberta, Edmonton, AB, Canada. 2Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.1Centre for the Studies of Asphyxia and Resuscitation, Neonatal Research Unit, Royal Alexandra Hospital, Edmonton, AB, Canada.Johnson 1,2,3, Megan O'Reilly 1,2, Tze-Fun Lee 1,2, Maryna Yaskina 3, Po-Yin Cheung 1,2 and Georg M.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |