No description available.

Thesis (M.S.)--University of Michigan, 1981. / eContent provider-neutral record in process. Description based on print version record.

Thesis (M.S.)--University of Michigan, 1987.

Thesis (M.S.)--University of Michigan, 1981. / eContent provider-neutral record in process. Description based on print version record.

Thesis (M.S.)--University of Michigan, 1983. / eContent provider-neutral record in process. Description based on print version record.

Thesis (M.S.)--University of Michigan, 1983. / eContent provider-neutral record in process. Description based on print version record.

Thesis (M.S.)--University of Michigan, 1987.

M.Cur. / 28-week premature infants are usually born with Respiratory Distress and need ventilator support in order to survive. However, because of all the associated complications of ventilation of premature infants, it is the practice in the NICU's in this studies to extubate these infants as soon as possible to either nasal continuous positive airway pressure (nCPAP) or nasal cannula (nc). For this study the choice of ventilation was High-Frequency Oscillation (HFO). It is known that during HFOV, Fi02 and MAP constitute the oxygenation needed to ventilate these infants. During weaning the Fi02 is reduced to :s 30% and the MAP gradually to :s 8-10 cm H20 to enable extubation. There are not enough guidelines as to the ideal MAP at which to extubate a HFOV 28-week premature infant to nCPAP or nco The purpose of this study was, firstly, to determine the recommended optimal MAP to successfully extubate a 28-week HFOV premature infant to either nCPAP or nc and, secondly, to formulate guidelines and recommendations for use by the attending neonatal nursing staff, doctors and clinicians for optimal nursing and management of the HFOV premature infant. This is a non-experimental quantitative study with a retrospective, descriptive survey, case study design. All 28-week premature infants that were initially ventilated on a HFOV during the period May 2000 to September 2002 in two private Neonatal Intensive Care Units in Gauteng and extubated to nCPAP or nc were incorporated into this study. The study was done in 3 phases. The first involved an in-depth literature survey in which the physiological and biographical variables that were included in the data collection instrument were identified. The second phase involved collecting the data from the infant's medical files, analysing the data and identifying any correlation of the data. In the third phase guidelines and recommendations for neonatal nursing staff, doctors and any attending clinicians were formulated. The initial settings of the HFOV, as well as the settings at a MAP of 8 cm H20, and the settings of the HFOV prior to extubation were recorded and analysed. The premature infant's initial blood gas and peripheral saturation after commencement of ventilation, as well as at a MAP of 8 cm H20 and prior extubation were recorded and analysed. The physiological stability of the premature infants, 12 hours after extubation, formed the criteria of successful extubation and any need for re-intubations was considered failure criteria. There are a lack of protocols and guidelines for neonatal nurses, doctors and clinicians as to guide them in the nursing of HFOV 28-week premature infants. The analysed data assists in drawing up guidelines for nursing the 28-week premature HFOV infant.

Digoxin, a steroidal glycoside that inhibits Na⁺/K⁺-ATPase, is the most commonly prescribed cardiac medication in North America. Blood levels of this drug are routinely measured to reduce the risks of toxicity. Reports questioning the specificity of antisera used in radioimmunoassays for serum digoxin measurements began to appear after 1975¹ when plasma from patients with renal failure, not on glycoside therapy, showed false-positive digoxin levels. Since then, digoxin-like immunoreactive substances (DLIS) have been found in sera from patients with hepatic failure, hypertension, pre-eclampsia, in amniotic fluid and cord blood. Some of the highest values for DLIS have been detected in premature infants, where levels have often exceeded the therapeutic range (0.2-2.0 µg/L) for digoxin. Cord blood has been identified as a rich source of DLIS. Dahl et al² were the first to suggest that a circulating saluretic substance "endoxin", may cause hypertension in salt sensitive rats. Gruber et al³ reported on the existence of digoxin-like factor(s) in the plasma of volume-expanded dogs. Plasma from these dogs inhibited Na⁺/K⁺ATPase activity. A number of other studies have supported the concept that such digoxin-like factors may be of etiological significance in hypertension⁴. In view of these observations, a study was undertaken to isolate and fractionate DLIS from mixed cord blood and determine whether or not any of this digoxin-like material possessed Na⁺/K⁺-ATPase inhibitory properties. Cord blood collected in the Grace Hospital Maternity Unit (Vancouver, BC), was pooled and DLIS extracted using C₁₈,R-Sep Paks. Extracts were resolved by high performance liquid chromatography (HPLC) into several fractions containing digoxin equivalent immunoactivity as measured by radioimmunoassay (RIA). A number of steroids and bile acids (dehydroepi-androsterone-sulfate, cortisone, Cortisol, deoxycortisone, ∆⁴androstene-dione, progesterone and glycochenodeoxycholic acid) cross-reacted with digoxin antisera and had HPLC retention times similar to DLIS-containing fractions. The ability of HPLC generated DLIS positive cord blood fractions to inhibit Na⁺/K⁺-ATPase activity was determined in three different assay systems; red cell ⁸⁶Rb uptake canine kidney-Na⁺/K⁺-ATPase and red cell membrane-Na⁺/K⁺-ATPase. At least six fractions contained DLIS and inhibited Na⁺/K⁺-ATPase activity. Inhibition varied with the assay system used but none of the fractions inhibited ⁸⁶Rb uptake by erythocytes. One fraction (which eluted at 29 minutes) contained progesterone; 72% of the inhibitory activity present in this fraction was attributable to this steroid. Another inhibitory fraction co-eluted with dehydroepiandrosterone-sulfate (DHEAS-S). The only fractions found to inhibit both the red cell membrane and canine kidney Na⁺ /K⁺-ATPase enzymes eluted at 7 and 29 minutes. In summary, a number of digoxin-like immunoreactive substances were isolated from cord blood by HPLC fractionation and found to inhibit Na⁺/K⁺-ATPase activity. Inhibition varied with the assay system used. There was no apparent correlation between inhibition and digoxin immunoreactivity. Very large quantities (500 mL) of cord blood were extracted to demonstrate these properties. It remains to be determined whether or not DLIS isolated during the perinatal period is of physiological significance. / Medicine, Faculty of / Pathology and Laboratory Medicine, Department of / Graduate

Hospital treatment environments have become a major concern in recent years. Noise and illumination are potential stress sources in hospitals. The purpose ofthis study was to examine the effects of hospital noise levels and ambient illumination on newborn infants (neonates). Noise levels and lighting were varied and the effect upon neonatal heart rate, respiration rate, blood pressure, and oxygen consumption were measured. These measures are sensitive tosympathetic nervous system reactivity such as that brought about by stressful environments. In addition, noise and lighting levels were measured to determine if differences existed across conditions. Psychophysiological responses to various noise and lighting levels varied within and across neonates with some changes in the expected direction. Some unexpected results of Quiet Time were noted among neonatal intensive care staff and hospital personnel.