e-Journal of Neonatology ResearchVolume 1, Issue 2, Summer 201183 UseofaNewDopplerUmbilicalCordClamptoMeasure Heart Rate in Newborn Infants in the Delivery Room Robert P. Lemke MD1, Michael Farrah BMET2, and Paul J. Byrne MBChB1 1Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada 2Department of Clinical Engineering, University of Alberta, Edmonton, Alberta, Canada Address correspondence:Robert Lemke, MD Stollery Childrens Hospital 3A3 Walter C Mackenzie HSC 8440 112 St NW Edmonton, Alberta T6G 2B7 Email: rplemke@shaw.ca Author Disclosure: All three authors have applied for a patent on the device described in this paper in multiple jurisdictions. ABSTRACT Objective:Asaninitialproofofconcept,todeterminewhetheraprototype umbilicalcordclampcontaininga Doppler ultrasound probe could quickly detect and accurately measure the heart rate of term newborns 5 min after birth. Methods: Clinically stable, spontaneously breathing newborns in room air, 37weeks gestation, had the prototype clamp applied to the base of their umbilical cord. We noted the time needed to detect a signal and then monitored the audible Doppler pulsations for approximately 1 minute while we simultaneously palpated the femoral pulse to confirm a 1:1 correlation. Results: A total of 16 term infants (9 female, GA 392 weeks, BW 3265425 grams, one minute Apgar 82, five minute Apgar 91) had the cord clamp applied. In all cases a Doppler signal was detected immediately after contact with the skin, and remained strong and correlated 1:1 with the palpated pulse for at least one minute. Movement and crying resulted in some noise but the Doppler heart rate signal was unaffected. Conclusion: Under controlled conditions, a prototype umbilical cord clamp containing a Doppler ultrasound probe wasabletodetectandmonitortheheart rateof16healthynewbornsafterbirth.Thetechniquehaspotential applications in guiding newborn resuscitation and requires further study. Key words: newborn, Doppler, resuscitation, newborn heart rate monitor, delivery room INTRODUCTION The transition from fetus to an air-breathing infantisacomplex physiologicalprocess.1 Although most babies are successful in this regard,a significantnumberrequiresome emergentassistance during this transition,2-4 andresuscitationinterventionsarenot themselveswithoutrisk.5-7Fundamental to thedecisionmakingprotocoldescribedin theNeonatalResuscitationProgram developedbytheAmericanHeart Association, is accurate real time knowledge of a newborn infants rapidly changing heart New Doppler Umbilical Cord ClampLemke et al e-Journal of Neonatology ResearchVolume 1, Issue 2, Summer 201184 rate.1,3,7 Continuous electronic monitoring of fetusesinutero,andofolderinfants in nurseries commonly occurs, and yet in the newborn during the critical first few minutes oflife,heartratemeasurementroutinely relies on simple palpation and auscultation.1 This critical information, used to initiate and guideresuscitationis typicallyonly intermittently obtained, difficult to verify in retrospect,andwhendone understressful circumstancesissubjecttoerror.1,6,8-10 Althoughmorerecently,electronic monitoringhasbeenusedinthedeliverysuite for neonates immediately after delivery a number of problems remain.1,11First, the blood,mucus,amnioticfluidandvernix caseosa, which coversnewborns must first becleanedfromtheskintoensurethat adhesiveprobesstick andgoodcontact betweentheskinandprobeisachieved.10 Even in experienced hands, application takes time and may paradoxically divert attention awayfromtheactual resuscitation.12 Second,themostinvestigatedmonitoring modality,pulse oximetry,dependsongood tissueperfusiontoensureanerrorfree signal.12,13 Unfortunatelyperfusionis poorestinthosebabieswhoarethemost compromised. Finally, in all cases there is a timedelaybetweenthetimetheumbilical cord is cut and the baby is transferred to the overheadwarmerbeforeauscultation and/or palpation can occur.3,7 WenotedthatDopplerultrasoundisan effective method to quickly detect pulsation thatisunaffectedbycontaminationofthe skinwithbodilyfluids. Moreoverwe recognizedthatclampingadevicetothe umbilicalcordcanprovidea robust mechanicalmethodoffixationthatis unaffected by the presence of bodily fluids. In fact the umbilical cord is an ideal site for suchamonitoringdevice becauseitis centrallylocatedonthebody,universally present,containsnopain receptorsandis infrequently needed after birth. We therefore envisionedanew umbilicalclamp,housing anintegralwirelessDopplerultrasound probe,whichis quickandsimpletofirmly attach to the babys cord immediately after birth.The heartratedatageneratedbythe devicecouldbetransmittedwirelesslyin realtime toamonitorforaudibleand numericdisplayanddatatrendingand storage. METHODS This pilot study was reviewed and approved by the Human Ethics and Research Board of the University of Alberta. Informed consent was obtained from the mother prior to birth for each patient enrolled. In order to prove our concept, we developed asimpleprototypecord clamp(Figure1) whichconsistedofamilledpolyethylene plastic housing through which the umbilical cord passed and positioned a pencil Doppler ultrasound probe with its tip covered in gel (KovenTechnologies,StLouis,Missouri) againstthe infantsabdominalwallatthe baseofthecord.Wehypothesizedthat this umbilicalclamp,woulddetecta pulsationintheintra-abdominalarteries within5 secondsofapplicationtotheskin anddosoforatleast1minutewithinthe first5 minutesafterbirth.Moreover,this pulsationwouldcorrelate1:1withthe heartbeat asdeterminedbyconcurrent palpation of the femoral pulse. The intended pilot study population were clinically stable, spontaneously breathingnewbornsinroom air, 37weeksgestation,whodidnot require resuscitationbeyondsimple stimulation.Anyinfantwithasuspected congenital anomaly,orwhowasrequiring oxygenorventilatorysupport,ora gestational age