Non-invasive cardiac output monitoring in preterm neonates
| dc.contributor.advisor | Smith, Johan | en_ZA |
| dc.contributor.advisor | De Boode, Willem-Pieter | en_ZA |
| dc.contributor.advisor | Lawrenson, John | en_ZA |
| dc.contributor.author | Van Wyk, Lizelle | en_ZA |
| dc.contributor.other | Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Paediatrics and Child Health. | en_ZA |
| dc.date.accessioned | 2021-11-21T15:33:33Z | |
| dc.date.accessioned | 2021-12-22T14:21:48Z | |
| dc.date.available | 2021-11-21T15:33:33Z | |
| dc.date.available | 2021-12-22T14:21:48Z | |
| dc.date.issued | 2021-12 | |
| dc.description | Thesis (PhD)--Stellenbosch University, 2021. | en_ZA |
| dc.description.abstract | ENGLISH ABSTRACT: Neonatal hemodynamic compromise is linked to numerous adverse neonatal outcomes. Objective, comprehensive, continuous hemodynamic monitoring of the systemic circulation, in conjunction with the pulmonary system, is required to timeously intervene and improve outcomes. Non-invasive cardiac output monitoring utilising bioreactance, a specific type of thoracic electrical biosensing technology (TEBT), may offer such a solution. The overall aim of this research was to determine the use of bioreactance as a comprehensive, non-invasive cardiac output monitor in preterm neonates (<37 weeks). Research aims included determining (1) agreement (bias and precision) and (2) trending ability of bioreactance. Further aims were to determine the use of bioreactance in monitoring hemodynamic parameters and thoracic fluid content in the transitional period (first 72 hours of life) and during respiratory support in preterm neonates. In a prospective, observational, longitudinal cohort study, the agreement (accuracy and precision) of bioreactance (BR), as compared to transthoracic echocardiography (TTE), for estimating cardiac output (CO) and stroke volume (SV) in a cohort of stable preterm neonates during the transitional period, was investigated. Bland Altman analyses showed a high bias, indicating poor accuracy, and wide limits of agreement, indicating poor precision, of BR as compared to TTE. A high percentage error indicated non- interchangeability of BR with TTE. Bias was shown to be affected by gestational age, birth weight, continuous positive airway pressure (CPAP), patent ductus arteriosus (PDA) and CO category. Despite a new technology’s inaccuracy and lack of absolute number agreement, it could possibly be a valuable trending monitor, if reference values were known. In the same cohort, the average values for BR-derived hemodynamic parameters (heart rate ( HR), blood pressure ( BP), SV, CO, total peripheral resistance ( TPR)) w ere described. All parameters were associated with postnatal age. Changes were in line with expected transitional changes, as described in the literature. BR may therefore be valuable to monitor the transitional period in preterm neonates. In continued accuracy analysis, the ability of BR, as compared to TTE, to track temporal changes in SV and CO was investigated. Four-quadrant and polar plots were used to assess BR trending ability. Concordance rate was lower than the accepted benchmarks, when using a 5% and 10% exclusion zone. Angular bias was high, radial limits were wide and radial concordance was poor; indicating a poor trending ability. Trending parameters were significantly associated with postnatal age, PDA, and CO category but not gestational age, birth weight or CPAP. BR, as compared to TTE, does not provide good trending analysis of CO and SV and should be used with caution in neonatology to direct therapeutic decisions. A narrative systematic review was performed to determine the agreement and trending ability of electrical biosensing technology (EBT) in neonates, including the current research. Only thoracic EBT studies, with TTE as comparator, were available for inclusion, up to December 2020. High heterogeneity was apparent in the eligible studies, due to varying gestational and chronological ages, birth weight, disease states, ventilation requirements, inotropic support and surgical intervention, which made meta-analysis impractical. Only agreement studies were available with no studies reporting trending analysis. Effect direction plots were used to report outcome measures (bias, percentage error). Overall, most studies showed that EBT was not interchangeable with TTE. Results remained similar in sub-analyses for preterm vs term neonatal populations, different respiratory support modes, cardiac anomalies and type of TEBT technology. In a post hoc analysis of the cohort study, BR-derived thoracic fluid content (TFC) parameters were described. TFC, another hemodynamic parameter, may be able to identify pulmonary fluid overload states, that may compromise cardiac function or be the consequence of cardiac dysfunction. Absolute TFC and cumulative TFC change from baseline (TFC and TFCd0, respectively) decreased over the first 72 hours of life. Both TFC and TFCd0 showed significant associations with clinical variables (gestational age, postnatal age, respiratory support mode). Sub-analyses according to respiratory support type and a pre-and post -intervention analysis was performed. TFC and TFCd0 showed significant pre- and post-intervention differences between respiratory intervention groups (CPAP and CPAP+surfactant). Neither TFC nor TFCd0 were associated with PDA in the transitional period. TFC and TFCd0 may offer the ability to monitor lung fluid during the transitional period in preterm neonates. In c onclusion, the agreement and trending of bioreactance in preterm neonates in the transitional period is questionable. Numerous physiological and interventional parameters influence this. However, on an individual level, BR may be able to monitor hemodynamic parameters, as parameters showed changes in the same direction as described in transitional physiology. Currently, bioreactance should be used with caution in the neonatal population to dictate therapeutic interventions. More research is required before bioreactance can be used at the bedside to replace transthoracic echocardiography. | en_ZA |
| dc.description.abstract | AFRIKAANSE OPSOMMING: Neonatale hemodinamiese kompromie hou verband met talle nadelige neonatale uitkomste. Objektiewe, omvattende, deurlopende hemodinamiese monitering van die sistemiese sirkulasie, tesame met die pulmonale sisteem, is nodig om betyds in te gryp en die uitkomste te verbeter. Nie-indringende monitering van kardiale omset met behulp van bioreaktansie, 'n spesifieke tipe torakale elektriese biosensietegnologie (TEBT), kan so 'n oplossing bied. Die algemene doel van hierdie navorsing was om die gebruik van bioreaktansie (BR) as 'n omvattende, nie-indringende kardiale omset monitor in premature pasgeborenes (<37 weke) te bepaal. Navorsingsdoelstellings was die bepaling van (1) ooreenkoms en (2) tydsanalise-vermoë van BR. Verdere doelstellings was om die gebruik van BR te bepaal by die monitering van hemodinamiese parameters en die longvloeistof in die oorgangsperiode (eerste 72 uur van lewe) en tydens respiratoriese ondersteuning van vroeggebore pasgeborenes. In 'n voornemende, waarnemingsstudie was die ooreenkoms (akkuraatheid en presisie) van bioreaktansie (BR), vergeleke met transtorakale eggokardiografie (TTE), vir die beraming van kardiale omset (KO) en slagvolume (SV) in 'n groep stabiele vroeggebore babas tydens die oorgangstydperk, ondersoek. Bland Altman-ontledings het ‘n hoë vooroordeel, duidend op swak akkuraatheid, en wye grense van ooreenstemming, duidend op swak presisie, getoon. 'n Hoë persentasie fout (>30%) het gedui op die onverwisselbaarheid van BR met TTE. Daar was getoon dat vooroordeel beïnvloed word deur die gestasie, geboortegewig, aanhoudende positiewe druk asemhaling (APDA), patente ductus arteriosus (PDA) en KO- kategorie. Ten spyte van 'n nuwe tegnologie se onakkuraatheid en gebrek aan absolute getal-ooreenstemming, kan dit belangrike 'n neigingsmonitor wees, indien verwysingswaardes bekend is. In dieselfde groep was die gemiddelde waardes vir BR-afgeleide hemodinamiese parameters (hartspoed, bloeddruk, SV, KO, totale perifere weerstand)beskryf. weerstand) beskryf. Al die parameters was geassosieer met die postnatale ouderdom. Veranderings was in ooreenstemming met die verwagte oorgangstydperk veranderinge, soos beskryf in die literatuur. BR kan dus waardevol wees om die oorgangsperiode by vroeggebore pasgeborenes te monitor. In voortgesette akkuraatheidsanalise was die vermoë van BR, in vergelyking met TTE, om tyds veranderinge in SV en KO te meet, ondersoek. Vier-kwadrant- en polêre grafieke was gebruik om BR-tydsanalise-vermoë te bepaal. Die ooreenstemmingskoers was laer as die aanvaarde maatstawwe, met die gebruik van 'n uitsluitingsone van 5% en 10%. Polêre hoek was hoog, radiale grense was wyd en radiale ooreenstemming was swak; alles duidend op 'n swak tydsanalise-vermoë. Tydsanalise-vermoë parameters was beduidend geassosieer met die postnatale ouderdom, PDA en KO kategorie, maar nie gestasie, geboortegewig of APDA nie. BR, in vergelyking met TTE, bied nie goeie tydsanalise-vermoë van KO en SV nie en moet met omsigtigheid in die neonatale tydperk gebruik word om terapeutiese besluite te neem. 'n Beskrywende sistematiese oorsig was uitgevoer om die ooreenkoms en tydsanalise-vermoë van elektriese biosensietegnologie (EBT) in die neonatal populasie te bepaal, insluitend die huidige navorsing. Slegs torakale EBT-studies, met TTE as vergelyker, was beskikbaar vir insluiting. Hoë heterogeniteit was duidelik in die ingeslote studies as gevolg van wisselende swangerskapstyd, kronologiese ouderdomme, geboortegewig, siektetoestande, ventilasievereistes, inotropiese ondersteuning en chirurgiese ingryping, en het meta-analise onprakties gemaak. Slegs ooreenkomsstudies was beskikbaar vir analise, en geen studies het verslag gedoen oor tydsanalise-vermoë nie. Effekrigtingsdiagramme was gebruik om resultate (vooroordeel, persentasie fout) aan te toon. Oor die algemeen, het die meeste studies getoon dat EBT nie met TTE verwissel kon word nie. Resultate het dieselfde gebly in sub-ontledings vir vroeggebore in vergelyking met volterm babas, verskillende respiratoriese ondersteuningsmodaliteite, hartafwykings en die tipe TEBT-tegnologie. In 'n post hoc-analise van die kohortstudie, was BR-afgeleide torakale vloeistofinhoud (TVI) parameters beskryf. TVI, nog 'n hemodinamiese parameter, mag pulmonale vloeistofoorladingstate kan identifiseer, wat hartfunksie in gevaar mag stel of die gevolg van hartdisfunksie mag wees. Absolute TVI- en kumulatiewe TVI- verandering vanaf basislyn (onderskeidelik TVI en TVId0) het gedurende die eerste 72 uur van die lewe afgeneem. Beide TVI en TVId0 het beduidende assosiasies getoon met kliniese veranderlikes (gestasie, postnatale ouderdom, en respiratoriese ondersteuningsmodaliteit). Sub-ontledings volgens die tipe respiratoriese ondersteuning en 'n voor- en na-intervensie-analise, was uitgevoer. TVI en TVId0 het beduidende verskille voor- en na- intervensie getoon tussen respiratoriese intervensiegroepe APDA en APDA + surfaktant). Nie TVI of TVId0 was ge-assosieer met ‘n PDA in die oorgangstydperk. TVI en TVId0 mag die vermoë bied om longvloeistof te monitor gedurende die oorgangsperiode by vroeggebore pasgeborenes. Ten slotte, die akkuraatheid en tydsanalise-vermoë van BR by vroeggebore pasgeborenes is twyfelagtig. Talle fisiologiese en intervensionele aspekte mag dit beïnvloed. Op ‘n individuele vlak, mag BR in staat wees om hemodinamiese parameters te monitor, aangesien BR-parameters veranderinge in dieselfde rigting getoon het, soos beskryf in oorgangsfisiologie. Tans moet bioreaktansie met omsigtigheid in die neonatale populasie gebruik word om terapeutiese intervensies te dikteer. Meer navorsing is nodig voordat bioreaktansie gebruik kan word om transtorakale eggokardiografie te vervang. | af_ZA |
| dc.description.version | Doctoral | en_ZA |
| dc.format.extent | 152 pages | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/10019.1/123794 | |
| dc.language.iso | en_ZA | en_ZA |
| dc.publisher | Stellenbosch : Stellenbosch University | en_ZA |
| dc.rights.holder | Stellenbosch University | en_ZA |
| dc.subject | Pediatric cardiology | en_ZA |
| dc.subject | Physiology | en_ZA |
| dc.subject | Hemodynamic monitoring | en_ZA |
| dc.subject | Preterm infants | en_ZA |
| dc.subject | Neonates | en_ZA |
| dc.subject | UCTD | en_ZA |
| dc.title | Non-invasive cardiac output monitoring in preterm neonates | en_ZA |
| dc.type | Thesis | en_ZA |