152 research outputs found
NNP09-ArticleHF-v71(Supplementary)_(1) – Supplemental material for A Novel Auditory Display for Neonatal Resuscitation: Laboratory Studies Simulating Pulse Oximetry in the First 10 Minutes After Birth
No full textSupplemental material, NNP09-ArticleHF-v71(Supplementary)_(1) for A Novel Auditory Display for Neonatal Resuscitation: Laboratory Studies Simulating Pulse Oximetry in the First 10 Minutes After Birth by Jelena Zestic, Birgit Brecknell, Helen Liley and Penelope Sanderson in Human Factors: The Journal of Human Factors and Ergonomics Society</p
Devices for administering ventilation at birth: a systematic review
No full textCONTEXT: Positive pressure ventilation (PPV) is the most important intervention during neonatal resuscitation.
OBJECTIVE: To compare T-piece resuscitators (TPRs), self-inflating bags (SIBs), and flow-inflating bags for newborns receiving PPV during delivery room resuscitation.
DATA SOURCES: Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, Cochrane Database of Systematic Reviews, and trial registries (inception to December 2020).
STUDY SELECTION: Randomized, quasi-randomized, interrupted time series, controlled before-and-after, and cohort studies were included without language restrictions.
DATA EXTRACTION: Two researchers independently extracted data, assessed the risk of bias, and evaluated the certainty of evidence. The primary outcome was in-hospital mortality. When appropriate, data were pooled by using fixed-effect models.
RESULTS: Meta-analysis of 4 randomized controlled trials (1247 patients) revealed no significant difference between TPR and SIB for in-hospital mortality (risk ratio 0.74; 95% confidence interval [CI] 0.40 to 1.34). Resuscitation with a TPR resulted in a shorter duration of PPV (mean difference −19.8 seconds; 95% CI −27.7 to −12.0 seconds) and lower risk of bronchopulmonary dysplasia (risk ratio 0.64; 95% CI 0.43 to 0.95; number needed to treat 32). No differences in clinically relevant outcomes were found in 2 randomized controlled trials used to compare SIBs with and without positive end-expiratory pressure valves. No studies used to evaluate flow-inflating bags were found.
LIMITATIONS: Certainty of evidence was very low or low for most outcomes.
CONCLUSIONS: Resuscitation with a TPR compared with an SIB reduces the duration of PPV and risk of bronchopulmonary dysplasia. A strong recommendation cannot be made because of the low certainty of evidence. There is insufficient evidence to determine the effectiveness of positive end-expiratory pressure valves when used with SIBs
The Effect of Shape and Bone Mineral Density Variation on Stress Distribution in the Equine Third Metacarpal Bone
No full textOne of the major causes of career-ending injury and euthanasia of Thoroughbred racehorses is catastrophic fracture to the condyles of the third metacarpal bone (MC3). These injuries incur an economic cost to the industry, are detrimental to equine welfare, and have a negative impact on the public perception of the sport of racing. The MC3 is the main weight-bearing bone in the forelimb, so even if the fracture can be treated, compensatory gait patterns will often lead to support limb laminitis. Knowledge of the risk factors and pathogenesis of fracture is required to predict and prevent third metacarpal fracture. The aim of this thesis was to investigate how variation in MC3 geometry and material properties affects mechanical stress in the cartilage and bone under load. The magnitude and distribution of the mechanical stress was considered here as a surrogate measure of the likelihood of joint pathology. In the first part of this thesis, the influence of the sagittal ridge angle on cartilage stress distributions was investigated. To achieve this, a finite element model of the metacarpo-phalangeal joint was developed based on computed tomography (CT) and magnetic resonance imaging (MRI) data. The geometry of the sagittal ridge was then mathematically morphed and the resulting cartilage stress was analysed. The von Mises stress distribution and contact pressure results of the converged model were comparable to similar models in the literature. Reducing the prominence of the sagittal ridge (by decreasing the angle at the apex) was found to increase stress in cartilage regions where fracture initiation was known to occur. The second experiment used CT images of the left metacarpo-phalangeal joint from 40 Thoroughbred racehorses to create a statistical shape model of the MC3 epiphysis. Subchondral bone mineral density was also incorporated into the model to investigate correlated modes of variation in the sample population. The results of this study described the statistical shape variation of the MC3, and how shape was related to BMD distribution. Creating bone geometries for a FE model generally requires CT imaging, the availability of which can be limited. In the following study, partial least squares regression (PLSR) was assessed as a method of reconstructing 3D models of the MC3 epiphysis from sparse morphometric data. We found the variation in shape was such that predictive reconstruction using PLSR, using two easily obtained measurements, was more accurate than an approximation of each subject using the population mean. The final section of this study used finite element modeling to examine the effects of variation in BMD distribution on stress fields produced in the joint under load. To achieve this, inhomogeneous bone properties were altered according to the principal modes of variation found in the population. There was a region of high stress in all models in the palmar aspect of the parasagittal groove, where a high proportion of lateral condylar fractures initiate in this location. Further investigation into these differences may improve understanding of how patterns of bone remodeling have the potential to predispose the joint to injury. In conclusion, this study shows that there is significant geometric variation in the MC3 epiphysis. It also shows that the influence of geometry and BMD distribution on the location and magnitude of stress in the bone under load can be non-intuitive. Finite element modelling is a powerful tool able to incorporate this variation. This research describes a novel workflow to rapidly generate FE models of the MC3 bone, which incorporate shape and material properties. These models and workflows have the potential to impact clinical assessment and prediction of MC3 fracture
Lung recruitment and endotracheal suction in ventilated preterm infants measured with electrical impedance tomography
No full textAims\ud
\ud
Although suctioning is a standard airway maintenance procedure, there are significant associated risks, such as loss of lung volume due to high negative suction pressures. This study aims to assess the extent and duration of change in end-expiratory level (EEL) resulting from endotracheal tube (ETT) suction and to examine the relationship between EEL and regional lung ventilation in ventilated preterm infants with respiratory distress syndrome.\ud
\ud
Methods\ud
\ud
A prospective observational clinical study of the effect of ETT suction on 20 non-muscle-relaxed preterm infants with respiratory distress syndrome (RDS) on conventional mechanical ventilation was conducted in a neonatal intensive care unit. Ventilation distribution was measured with regional impedance amplitudes and EEL using electrical impedance tomography.\ud
\ud
Results\ud
\ud
ETT suction resulted in a significant increase in EEL post-suction (P < 0.01). Regionally, anterior EEL decreased and posterior EEL increased post-suction, suggesting heterogeneity. Tidal volume was significantly lower in volume-guarantee ventilation compared with pressure-controlled ventilation (P = 0.04).\ud
\ud
Conclusions\ud
\ud
ETT suction in non-muscle-relaxed and ventilated preterm infants with RDS results in significant lung volume increase that is maintained for at least 90 min. Regional differences in distribution of ventilation with ETT suction suggest that the behaviour of the lung is heterogeneous in nature
- …
