128 research outputs found
Establishing normal values of central venous pressure in very low birth weight infants
No full textThe objective of this paper is to establish a reference range of central venous pressure (CVP) values during the first 4 days of life in very low birth weight (VLBW) infants. A prospective observational study with continuous monitoring of CVP in VLBW newborns who had an umbilical venous catheter (UVC) positioned in or near the right atrium is conducted. All UVCs were inserted as part of normal care of the infants. The mean CVP (mCVP) was monitored for 72 h from recruitment, or until the UVC was removed. The mean mCVP was calculated for each infant. The median of the mean mCVPs was then calculated. Data were analysed in 17 infants. The median gestational age was 27 weeks and median birth weight was 940 g. Sixteen were mechanically ventilated and of these, six also received continuous positive airway pressure (CPAP) during the study period. One infant received no respiratory support. One infant died during the study period. The lowest mean mCVP was 2.8 mmHg and the highest was 13.9 mmHg. The median mean mCVP was 4.9 mmHg (interquartile range 4.4–6.1). The normal range of CVP in VLBW infants during the first 4 days of life is wider than previously suggested
Perfluorocarbon dosing when starting partial liquid ventilation: Haemodynamics and cerebral blood flow in preterm lambs
No full textBackground: Very preterm neonates can have severe lung disease and are prone to brain injury if cerebral blood flow fluctuates. Partial liquid ventilation (PLV) may benefit the lung disease, but it is unknown whether the administration of intratracheal perfluorocarbon when starting PLV affects haemodynamics or cerebral blood flow. Objectives: To determine if haemodynamics or cerebral blood flow are affected in preterm lambs receiving a dose of perfluorocarbon when starting PLV. Methods: Sixteen preterm lambs were randomised to either PLV or conventional mechanical ventilation. An intratracheal loading dose of 30 ml/kg of perfluorocarbon liquid (PLV group) or air (sham group) was instilled over 20 min. Data were collected continuously for 30 min from the start of dosing. Results: Cortical cerebral blood flow velocity, measured continuously with laser Doppler, was increased in the PLV group during the administration of perfluorocarbon and immediately thereafter (p = 0.0026); the highest mean increase in the PLV group was 27%. There was no difference in cortical cerebral blood flow variability (p = 0.96). There was a slightly lower mean arterial blood pressure in the PLV group; the heart rate did not differ between groups. The PaCO(2) was higher in the PLV group at 30 min - the difference between groups was not statistically significant (difference between means = 5.5 mm Hg, 95% confidence interval -2.7 to 13.7). Conclusions: Preterm lambs receiving a dose of tracheal perfluorocarbon at the start of PLV have an increased cortical cerebral blood flow velocity, but no change in cortical cerebral blood flow variability. Copyright (C) 2009 S. Karger AG, Base
Cerebral blood flow is not affected during perfluorocarbon dosing with volume-controlled ventilation
No full textAimsPerfluorocarbon administration increases cerebral blood flow. This can be mitigated by preventing a rise in carbon dioxide by adjusting pressure-controlled ventilation. Volume-controlled ventilation should prevent increases in arterial carbon dioxide and cerebral blood flow. This study aims to determine if cerebral blood flow is increased during administration of 10mL/kg of perfluorocarbon while using volume-controlled ventilation
An experimental model for the measurement of inspired gas temperatures in ventilated neonates
No full textObjective To determine the inspired gas temperature at points from the endo-tracheal tube (ETT) circuit manifold to the tip of the ETT in a model neonatal lung. Design A model lung attached to standard ventilator circuit, autofeed chamber and humidifier was ventilated using typical pressure-limited, time cycled settings. Temperatures were measured at various distances along the ETT using a K-type thermocouple temperature probe. Results The inspired gas temperature dropped from the circuit temperature probe site (40 degrees C) to the proximal end of the ETT (37 degrees C). The temperature dropped further as it passed through the exposed part of the ETT (34 degrees C) but then warmed again on entering the lung model so that the inspired gas at the distal end of the ETT was 37 degrees C. Statistically significant differences were found with a one-way ANOVA P-value of 0.05). Conclusions Inspired gas temperature drops as it passes through the circuit temperature probe site, the proximal end of the ETT and the exposed part of the ETT The inspired gas rewarms on entering the model lung and exits the ETT at the desired temperature. The effect of measuring temperature closer to the patient, setting the circuit temperature higher and/or increasing the ambient temperature through which the circuit passes, need to be evaluated
Gas exchange during perfluorocarbon liquid immersion: Life-support for the ex utero fetus
No full textBackground: Respiratory mortality and morbidity remain major consequences of extreme prematurity. Percutaneous transfer of oxygen and carbon dioxide is possible in the newborn human. Perfluorocarbon (PFC) liquids have excellent oxygen and carbon dioxide carrying capacity. Animals can breath immersed in perfluorocarbon liquids and maintain adequate gas exchange. Our hypothesis is that the combination of spontaneous tidal perfluorocarbon breathing and respiration through the skin immersed in perfluorocarbon wilt allow adequate gas exchange in the preterm newborn. In this pilot study we aimed to observe the effects of immersion in FC-77 perfluorocarbon liquid on the preterm lamb
Effect of the dose volume of perfluorocarbon when starting partial liquid ventilation
No full textObjective
The use of chilled condensers for the recovery of perfluorocarbon liquid in an experimental model of perfluorocarbon vapour loss during neonatal partial liquid ventilation
No full textBackground: Perfluorocarbon (PFC) vapour in the expired gases during partial liquid ventilation should be prevented from entering the atmosphere and recovered for potential reuse
An Advanced Expiratory Circuit for the Recovery of Perfluorocarbon Liquid From Non-Saturated Perfluorocarbon Vapour During Partial Liquid Ventilation: An Experimental Model
No full textBackground: The loss of perfluorocarbon (PFC) vapour in the expired gases during partial liquid ventilation should be minimized both to prevent perfluorocarbon vapour entering the atmosphere and to re-use the recovered PFC liquid
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