Date of Degree
Access restricted until 07/29/2020
MS (Master of Science)
Bates, Melissa L.
First Committee Member
Dagle, John M.
Second Committee Member
Pierce, Gary L.
One in every 10 infants is born premature, with premature being defined as being born before 37 weeks gestation. The immediate concerns of premature birth are fairly well understood, but the long-term consequences are much less known. Previous studies have shown pulmonary insufficiencies in adulthood, but less have looked at hemodynamic variables. None have investigated exercise and hypoxia intolerance in adults who survived prematurity. The goals of this study were to determine exercise capacity and hemodynamic response during exercise and hypoxia in prematurely born adults, as well as deriving pulse wave velocity in normoxia and hypoxia.
Preterm (N=10) and term-born, age-matched subjects (N=12) performed incremental exercise in normoxia (21% O2) or hypoxia (12% O2) until volitional maximum was reached. Subjects had arterial and venous catheters collecting blood gas concentration and blood pressure, and breath-by-breath metabolics gathering ventilation data.
Preterm and term-born subjects were well matched for anthropometrics, pulmonary, and exercise capacity values. The preterm adults had elevated heart rates, systolic blood pressure, pulse pressure throughout the exercise protocol in normoxia and hypoxia. The preterm group experienced an increased diastolic blood pressure and mean arterial pressure during normoxic exercise, but had a transient decrease in diastolic blood pressure and mean arterial pressure in hypoxia. Additionally, adults born prematurely had an increase aortic pulse wave velocity (aPWV).
With these findings, we aimed to determine if aortic stiffness was increased in premature infants at birth with the neonatal intensive care unit (NICU), or if there was a phenotype of premature aging in this population. Prior to beginning the study with the NICU, the effects of simulation on clinicians and researchers was investigated. Simulation is often used for noninvasive teaching or practicing procedures. No one has looked into the effect simulation has on research being done in an intensive care unit setting.
Bay 1 and 2 nurses (n=23) in the NICU were surveyed to rate their thoughts of clinical research, comfort with new research, comfort with simulation, and comfort with researchers not from the NICU. Nurses did not know what aspects of the NICU were overwhelming to researchers nor did they agree that researchers could identify infants stress cue. Nurses also reported discomfort communicating with parents about novel research technology. But overall, nurses support research in the NICU and are comfortable with new research knowing the research team participated in a NICU-specific simulation.
A questionnaire was also filled out by researchers (n=3), neonatal intensive care unit physicians (n=3) and nurses (n=3) prior to and after completing a research study simulation. Prior to simulation, scientists showed more unfamiliarity with the infants, the NICU setting, and simulation than did the physicians or nurses. Physicians and nurses, however, were not familiar with the technology the researchers used. The simulation alleviated the differences found among the groups.
Simulation improves nurses’ opinions of new technology and researchers coming into the NICU and working with patients. Simulation helps researchers familiarize themselves with the NICU and infants, while also improving the clinicians’ comfort with the technology and methods being used.
Hypertension, Hypoxia, Prematurity
x, 53 pages
Includes bibliographical references (pages 38-51).
Copyright © 2019 Christopher Richard Barnard
Barnard, Christopher Richard. "Abnormal vascular structure and function in survivors of prematurity." MS (Master of Science) thesis, University of Iowa, 2019.
Available for download on Wednesday, July 29, 2020