Clinical physiology and functional imaging
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Clin Physiol Funct Imaging · Jan 2018
The multi-ethnic global lung initiative 2012 and Third National Health and Nutrition Examination Survey reference values do not reflect spirometric measurements in Black boys and men from Tanzania.
The interpretation of spirometric results of Black Africans according to reference standards based on data from outside their native environment may lead to the wrong conclusions. This article aims to characterize the ventilatory capacity of boys and men from Tanzania according to forced expiratory volume in one second (FEV1 ), forced vital capacity (FVC), peak expiratory flow (PEF) and FEV1 /FVC based on the collected anthropological material and to compare them to NHANES III, Third National Health and Nutrition Examination Survey (NHANES III) African American predicted values and GLI2012 equations. The analysis included spirometric measurements of n = 295 participants from Tanzania. ⋯ All the spirometric measurements included in the analysis were statistically significantly correlated with age, body height, sitting height, trunk length and body weight. The application of prediction formulae developed for non-African populations overestimates the values for Black Africans. The results of spirometric measurements are ecosensitive and dependent on various external (environmental) factors.
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Clin Physiol Funct Imaging · May 2017
The impact of venous occlusion per se on forearm muscle blood flow: implications for the near-infrared spectroscopy venous occlusion technique.
The purpose of this study was to examine the effect of venous occlusion per se on forearm muscle blood flow, as determined by the near-infrared spectroscopy (NIRS) venous occlusion technique (NIRS-VOT). NIRS data were obtained from the flexor digitorum superficialis (FDS) muscle on the dominant arm of 16 young, ostensibly healthy participants (14 men and two women; 30 ± 6 year; 73 ± 7 kg). Participants completed a series of five venous occlusion trials while seated at rest, and a series of 12 venous occlusion trials during a reactive hyperaemia induced by 5 min of forearm arterial occlusion. ⋯ Moreover, the inclusion of more than one cardiac beat in the calculation of Q˙mus underestimated muscle blood flows, irrespective of the prevailing level of arterial inflow. These findings support the idea that venous occlusion per se affects the measurement of Q˙mus via the NIRS-VOT. Accordingly, it is recommended that Q˙mus is determined over the first cardiac beat when using the NIRS-VOT to assess microvascular blood flow of human forearm muscles.
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Clin Physiol Funct Imaging · May 2017
Fixed ratio or lower limit of normal for the FEV1 /VC ratio: relation to symptoms and extended lung function tests.
There is no general agreement on the spirometric definition of chronic obstructive pulmonary disease (COPD). The global initiative for obstructive lung disease recommends a fixed ratio between forced expiratory volume in one-second (FEV1 ) and forced vital capacity (FVC) of <0·7 (FR) for the diagnosis of COPD. European Respiratory Society and American Thoracic Society favour the use of the fifth percentile of the age-related FEV1 /FVC ratio (the lower limit of normal, LLN). ⋯ For IOS, variables and symptoms increasingly abnormal values were seen from never smokers to FR+LLN+. This study shows that subjects meeting both spirometric COPD criteria frequently have symptoms and findings at extended lung function tests compatible with the diagnosis. Also subjects meeting the fixed ratio criterion only tend to have more symptoms and lung function findings compatible with COPD than ever-smoking subjects with FEV1 /VC > 0·7.
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Clin Physiol Funct Imaging · Jan 2017
Comparative StudyAn echo-planar imaging sequence is superior to a steady-state free precession sequence for visual as well as quantitative assessment of cardiac magnetic resonance stress perfusion.
To assess myocardial perfusion, steady-state free precession cardiac magnetic resonance (SSFP, CMR) was compared with gradient-echo-echo-planar imaging (GRE-EPI) using myocardial perfusion scintigraphy (MPS) as reference. ⋯ GRE-EPI displayed higher agreement with the MPS results than SSFP despite significantly lower signal intensity, SNR and CNR.
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Clin Physiol Funct Imaging · Nov 2016
Review Meta AnalysisNear infrared spectroscopy for frontal lobe oxygenation during non-vascular abdominal surgery.
Cerebral deoxygenation, as determined by near infrared spectroscopy (NIRS), seems to predict postoperative complications following cardiac surgery. We identify the type of non-vascular abdominal surgery associated with cerebral deoxygenation and/or hyperoxygenation, how such deviations affect patient outcome, and whether maintained cerebral oxygenation improves outcome. ⋯ NIRS seems important for predicting neurological complications associated with LTx. Also, surgery in reverse Trendelenburg's position and in other types of abdominal surgery about one-fourth of the patients are subjected to episodes of cerebral deoxygenation that seems to predict a poor outcome. Although there are currently only few studies available for patients going through abdominal surgery, the available evidence points to that it is an advantage to maintain the NIRS-determined cerebral oxygenation.