BACKGROUND: The assessment of intravascular volume status is very important especially in children during anesthesia. Pulse pressure variation (PPV) and pleth variability index (PVI) are well known parameters for assessing intravascular volume status and fluid responsiveness. We compared PPV and PVI for children aged less than two years who underwent surgery in the prone position. METHODS: A total of 27 children were enrolled. We measured PPV and PVI at the same limb during surgery before and after changing the patients’ position from supine to prone. We then compared PPV and PVI at each period using Bland-Altman plot for bias between the two parameters and for any correlation. We also examined the difference between before and after the position change for each parameter, along with peak inspiratory pressure, heart rate and mean blood pressure. RESULTS: The bias between PPV and PVI was −2.2% with a 95% limits of agreement of −18.8% to 14.5%, not showing significant correlation at any period. Both PPV and PVI showed no significant difference before and after the position change. CONCLUSIONS: No significant correlation between PVI and PPV was observed in children undergoing surgery in the prone position. Further studies relating PVI, PPV, and fluid responsiveness via adequate cardiac output estimation in children aged less than 2 years are required.
Anesthesia ; Arterial Pressure ; Bias (Epidemiology) ; Blood Pressure ; Cardiac Output ; Child ; Extremities ; Fluid Therapy ; Heart Rate ; Humans ; Plethysmography ; Prone Position

It is challenging to predict fluid responsiveness, that is, whether the cardiac index or stroke volume index would be increased by fluid administration, in the pediatric population. Previous studies on fluid responsiveness have assessed several variables derived from pressure wave measurements, plethysmography (pulse oximeter plethysmograph amplitude variation), ultrasonography, bioreactance data, and various combined methods. However, only the respiratory variation of aortic blood flow peak velocity has consistently shown a predictive ability in pediatric patients. For the prediction of fluid responsiveness in children, flow- or volume-dependent, noninvasive variables are more promising than pressure-dependent, invasive variables. This article reviews various potential variables for the prediction of fluid responsiveness in the pediatric population. Differences in anatomic and physiologic characteristics between the pediatric and adult populations are covered. In addition, some important considerations are discussed for future studies on fluid responsiveness in the pediatric population.
Adult ; Blood Pressure ; Cardiac Output ; Child ; Fluid Therapy ; Humans ; Oximetry ; Plethysmography ; Pulse Wave Analysis ; Stroke Volume ; Ultrasonography ; Ultrasonography, Doppler

OBJECTIVE: To study the effect of bronchopulmonary dysplasia (BPD) on lung function in preterm infants. METHODS: According to the presence/absence or the severity of BPD, 72 preterm infants were divided into non-BPD group (n=44), mild BPD group (n=15) and moderate BPD group (n=13). Lung function was assessed by plethysmography on days 7, 14 and 28 after birth. RESULTS: The preterm infants in the three groups had gradual increases in tidal volume per kilogram (TV/kg), functional residual capacity (FRC), ratio of time to peak tidal expiratory flow to total expiratory time (%T-PF) and ratio of volume to peak tidal expiratory flow to total expiratory volume (%V-PF) on days 7, 14 and 28 after birth, while there were gradual reductions in effective airway resistance per kilogram (Reff/kg) and respiratory rate (RR) (P<0.05). Compared with the non-BPD group on days 7, 14 and 28 after birth, the mild and moderate BPD groups had significantly lower TV/kg, FRC, %T-PF, and %V-PF and significantly higher Reff/kg and RR (P<0.05). On day 7 after birth, the moderate BPD group had significantly higher airway resistance, Reff/kg and FRC/kg than the mild BPD group (P<0.05). CONCLUSIONS There is a certain degree of pulmonary function impairment in preterm infants with BPD. Dynamic monitoring of lung function by plethysmography is useful for assessing lung development in the neonatal period in these infants.
Bronchopulmonary Dysplasia ; Humans ; Infant, Newborn ; Infant, Premature ; Lung ; Plethysmography ; Respiratory Function Tests

OBJECTIVE: Multiple sclerosis (MS) is an inflammatory disease characterized by demyelinating plaques in the white matter. Chronic cerebrospinal venous insufficiency (CCSVI) has been proposed as a new hypothesis for the etiopathogenesis of MS disease. MS-CCSVI includes a significant decrease of cerebrospinal fluid (CSF) flow through the cerebral aqueduct secondary to an impaired venous outflow from the central nervous system. This study aimed to determine whether CSF flow dynamics are affected in MS patients and the contributions to differential diagnosis in active and chronic disease using phase-contrast magnetic resonance imaging (PC-MRI). MATERIALS AND METHODS: We studied 16 MS patients with chronic plaques (group 1), 16 MS patients with active plaques-enhanced on MRI (group 2), and 16 healthy controls (group 3). Quantitatively evaluation of the CSF flow was performed from the level of the cerebral aqueduct by PC-MRI. According to heart rates, 14–30 images were obtained in a cardiac cycle. Cardiac triggering was performed prospectively using finger plethysmography. RESULTS: No statistically significant difference was found between the groups regarding average velocity, net forward volume and the average flow (p > 0.05). Compared with the controls, group 1 and group 2, showed a higher peak velocity (5.5 ± 1.4, 4.9 ± 1.0, and 4.3 ± 1.3 cm/sec, respectively; p = 0.040), aqueductal area (5.0 ± 1.3, 4.1 ± 1.5, and 3.1 ± 1.2 mm2, respectively; p = 0.002), forward volume (0.039 ± 0.016, 0.031 ± 0.013, and 0.021 ± 0.010 mL, respectively; p = 0.002) and reverse volume (0.027 ± 0.016, 0.018 ± 0.009, and 0.012 ± 0.006 mL, respectively; p = 0.000). There were no statistical significance between the MS patients with chronic plaques and active plaques except for reverse volume. The MS patients with chronic plaques showed a significantly higher reverse volume (p = 0.000). CONCLUSION: This study indicated that CSF flow is affected in MS patients, contrary to the hypothesis that CCSVI-induced CSF flow decreases in MS patients. These findings may be explained by atrophy-dependent ventricular dilatation, which may occur at every stage of MS.
Central Nervous System ; Cerebral Aqueduct ; Cerebrospinal Fluid ; Chronic Disease ; Diagnosis, Differential ; Dilatation ; Fingers ; Heart Rate ; Humans ; Magnetic Resonance Imaging ; Multiple Sclerosis ; Plethysmography ; Prospective Studies ; Venous Insufficiency ; White Matter

PURPOSE: Diesel exhaust particles (DEPs) can induce and trigger airway hyperresponsiveness (AHR) and inflammation. The aim of this study was to investigate the effect of long-term DEP exposure on AHR, inflammation, lung fibrosis, and goblet cell hyperplasia in a mouse model. METHODS: BALB/c mice were exposed to DEPs 1 hour a day for 5 days a week for 3 months in a closed-system chamber attached to a ultrasonic nebulizer (low dose: 100 microg/m3 DEPs, high dose: 3 mg/m3 DEPs). The control group was exposed to saline. Enhanced pause was measured as an indicator of AHR. Animals were subjected to whole-body plethysmography and then sacrificed to determine the performance of bronchoalveolar lavage and histology. RESULTS: AHR was higher in the DEP group than in the control group, and higher in the high-dose DEP than in the low-dose DEP groups at 4, 8, and 12 weeks. The numbers of neutrophils and lymphocytes were higher in the high-dose DEP group than in the low-dose DEP group and control group at 4, 8, and 12 weeks. The levels of interleukin (IL)-5, IL-13, and interferon-gamma were higher in the low-dose DEP group than in the control group at 12 weeks. The level of IL-10 was higher in the high-dose DEP group than in the control group at 12 weeks. The level of vascular endothelial growth factor was higher in the low-dose and high-dose DEP groups than in the control group at 12 weeks. The level of IL-6 was higher in the low-dose DEP group than in the control group at 12 weeks. The level of transforming growth factor-beta was higher in the high-dose DEP group than in the control group at 4, 8, and 12 weeks. The collagen content and lung fibrosis in lung tissue was higher in the high-dose DEP group at 8 and 12 weeks. CONCLUSIONS: These results suggest that long-term DEP exposure may increase AHR, inflammation, lung fibrosis, and goblet cell hyperplasia in a mouse model.
Airway Remodeling ; Animals ; Bronchoalveolar Lavage ; Collagen ; Fibrosis ; Goblet Cells ; Hyperplasia ; Inflammation* ; Interferon-gamma ; Interleukin-10 ; Interleukin-13 ; Interleukin-6 ; Interleukins ; Lung ; Lymphocytes ; Mice* ; Nebulizers and Vaporizers ; Neutrophils ; Plethysmography ; Pneumonia ; Ultrasonics ; Vascular Endothelial Growth Factor A ; Vehicle Emissions*

PURPOSE: To evaluate the association of self-reported erectile function and endothelial function using the EndoPAT device. MATERIALS AND METHODS: We prospectively enrolled 76 men (age> or =40 years) after obtaining a complete medical history and a self-reported questionnaire (International Index of Erectile Function-5 [IIEF-5], SEP Q2, Q3). Endothelial function was noninvasively measured with an EndoPAT 2000, recorded as the reactive hyperemia index (RHI), and analyzed according to the patients' baseline characteristics. RESULTS: The mean patient age and IIEF-5 score were 62.50+/-8.56 years and 11.20+/-6.36, respectively. In comparing the RHI according to erectile dysfunction (ED) risk factors, the RHI was significantly lower in older subjects (p=0.004). There was no difference in the RHI according to age, body mass index, waist circumference, obesity, smoking habit, or other comorbidities. When the subjects were divided into four groups according to the severity of ED, no statistical differences in the RHI value were found among the groups. There was no difference in IIEF-5 according to the RHI when categorized according to the normal cutoff value or quartile ranges. The second subdomain of IIEF-5 (erection firmness) was significantly correlated with the RHI value (R=0.309, p=0.007); however, this was not the case with the other IIEF-5 subdomains. Self-assessment showed a tendency toward a negative correlation with the RHI value (R=-0.202, p=0.080). CONCLUSIONS: The role of endothelial function measurement by the EndoPAT in the evaluation and management of ED patients remains inconclusive. However, further studies are needed to validate the role of endothelial function measurement, by the EndoPAT or any other device.
Body Mass Index ; Comorbidity ; Endothelium ; Erectile Dysfunction ; Humans ; Hyperemia ; Male ; Obesity ; Plethysmography ; Prospective Studies ; Risk Factors ; Self-Assessment ; Smoke ; Smoking ; Waist Circumference

The present study reviews recently developed and commonly used methods for determination of body composition in vivo with relevance for nutritional assessment. Body composition measurement methods are continuously being improved, with the most commonly used methods being bioelectrical impedance analysis, dual energy X-ray absorptiometry, computed tomography, and magnetic resonance imaging or magnetic resonance spectroscopy. Recent developments include three-dimensional photonic scanning, quantitative magnetic resonance, and air displacement plethysmography. Collectively, these techniques allow for the measurement of fat, fat-free mass, bone mineral content, total body water, extracellular water, total adipose tissue and its subdepots (visceral, subcutaneous, and intermuscular), skeletal muscle, select organs, and ectopic fat depots.
Absorptiometry, Photon ; Adipose Tissue ; Body Composition ; Body Water ; Bone Density ; Electric Impedance ; Human Body ; Humans ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy ; Methods ; Muscle, Skeletal ; Nutrition Assessment ; Obesity ; Plethysmography ; Water

OBJECTIVEBody plethysmography is a typical method to measure functional residual capacity (FRC) and airway resistance (Raw). The aim of the study was to test the feasibility of measuring lung function with the body plethysmography in young children with acute lower respiratory tract infection (ALRI) by evaluating changes and prognosis of lung function for infants with ALRI with or without wheezing via body plethysmograph.

METHODPulmonary function tests (PFTs) were performed by using body plethysmography in 444 children with ALRI, aged 1-36 months, to assess their tidal breathing parameters such as ratio of time to peak tidal expiratory flow to total expiratory time (TPTEF/TE), ratio of volume to peak tidal expiratory flow to total expiratory volume (VPTEF/VE), plethysmographic functional residual capacity (FRCP), FRCP per kilogram (FRCP/kg), specific effective airway resistance (sReff), effective airway resistance (Reff), Reff per kilogram (Reff/kg), etc. According to whether there was wheezing or not, children who had ALRI with wheezing were classified as Group-W, or without wheezing as Group-N. Changes or correlations of tidal breathing parameters and plethysmographic parameters were compared.One hundred and three contemporaneous healthy controls aged 1-36 months underwent the same tests for comparison. And 36 wheezing children accepted PFTs at follow-up in recovery phase.

RESULTMean values of TPTEF/TE in Group-W,Group-N and the Control respectively were (20.5 ± 6.7)%,(22.8 ± 6.5)%,(34.6 ± 5.0)% (F = 110.500, P < 0.001), while VPTEF/VE respectively were (23.0 ± 6.3)%,(25.2 ± 6.8)%,(34.5 ± 4.2)% (F = 107.800, P < 0.001). Compared to the Control,Group-W and Group-N had significantly higher values of FRCP (226 vs. 176 vs. 172 ml, χ(2) = 64.870, P < 0.001), FRCP/kg(24.40 vs.17.80 vs.17.60 ml/kg,χ(2) = 68.890, P < 0.001), sReff(1.00 vs. 0.52 vs. 0.46 kPa·s,χ(2) = 75.240, P < 0.001), Reff (3.90 vs.2.74 vs.2.20 kPa·s/L, χ(2) = 36.480, P < 0.001) and Reff/kg [0.42 vs. 0.29 vs.0.22 kPa·s/(L·kg), χ(2) = 29.460, P < 0.001]. Although 25 (12.8%) wheezing children with ALRI had normal values of tidal breathing parameters, they already had increased FRCP, FRCP /kg, sReff, Reff and Reff/kg (t = 2.221, 1.997, 2.502, 2.587, 2.539, all P < 0.05). Values of FRCP and Reff in infants caught ALRI were inversely correlated to that of TPTEF/TE and VPTEF/VE (P < 0.05); 36 children with wheezing who accepted PFTs at follow-up had shown significant decline in the specific parameters of plethysmography such as FRCP, FRCP/kg, sReff, Reff and Reff/kg (Z = -1.999, -2.195, -2.038, -1.823, -2.054, all P < 0.05), while no improvement in the main parameters of tidal breathing such as TPTEF/TE.

CONCLUSIONMeasuring lung function with the body plethysmography in young children with ALRI is feasible. FRC and Raw, as special lung function testing parameters of body plethysmography, were sensitive indicators reflecting impairment of lung function in infants with ALRI (especially for children caught ALRI with wheezing) and shows significant correlation with parameters from lung function testing via tidal breathing. Therefore plethysmography is worthy of clinical promotion.

Airway Resistance ; physiology ; Case-Control Studies ; Child, Preschool ; Female ; Functional Residual Capacity ; physiology ; Humans ; Infant ; Lung ; physiopathology ; Male ; Plethysmography, Whole Body ; Respiratory Function Tests ; Respiratory Sounds ; diagnosis ; physiopathology ; Respiratory Tract Diseases ; diagnosis ; physiopathology ; Tidal Volume

Pulmonary function testing (PFT) is an important and fundamental method in the evaluation and treatment of respiratory diseases. Airway responsiveness assessed using histamine or methacholine by PFT is meaningful for the diagnosis of asthma. Spirometry is simple, and has been the most commonly used technique. However, in younger or uncooperative children, other commercially available tools such as impulse oscillometry (IOS), gas dilution, and plethysmography have been used. IOS is a noninvasive method that allows the measurement of airway mechanics (resistance [R] and reactance [X]) with minimal patient cooperation. Functional residual capacity (FRC) is one of the most important measurements obtained by gas dilution. Plethysmography is a gold standard to measure airway resistance and useful for lung function testing in infants. The purpose of this review is to help pediatric physicians being familiar with PFT techniques used in young children by discussing their principles, clinical applications, limitations, and current accessibility in Korea.
Airway Resistance ; Asthma ; Child* ; Diagnosis ; Functional Residual Capacity ; Histamine ; Humans ; Infant ; Korea ; Lung* ; Mechanics ; Methacholine Chloride ; Oscillometry ; Patient Compliance ; Plethysmography ; Respiratory Function Tests ; Spirometry

OBJECTIVETo evaluate the changes in subcortical white matter and corpus callosum volumes in patients with type 2 diabetes mellitus (T2DM).

METHODSHigh resolution three-dimensional T1-weighted fast spoiled gradient recalled echo magnetic resonance images were obtained from 16 T2DM patients and 16 normal controls, and 11 T2DM patients also received the same magnetic resonance imaging scans after insulin therapy for 1 year. Volumetric analysis was performed and analysis of covariance and paired t test were applied.

RESULTSA lower volume was demonstrated in T2DM patients than that in the normal controls in bilateral caudal middle frontal lobe, bilateral pars opercularis, right inferior parietal lobe, right inferior temporal lobe, right middle temporal lobe, and left transverse temporal lobe (all P<0.05). After insulin therapy for 1 year, the increased subcortical white matter of brain regions were demonstrated in left medial orbitofrontal lobe, right caudal middle frontal lobe, right inferior parietal lobe, right lingual lobe, right inferior temporal lobe, right middle temporal lobe, left transverse temporal lobe, left entorhinal lobe and left insular lobe at the follow-up level in T2DM patients compared with baseline level (P<0.05). The decreased volumes of subcortical white matter were observed in the bilateral paracentral lobe, right superior forntal lobe and right precuneus lobe in T2DM patients on insulin therapy for 1 year (P<0.05). A decreased trend of subcortical white matter was involved in corpus callosum (P>0.05) and a significant decreased volume was demonstrated in the middle posterior part of corpus callosum after insulin therapy for 1 year(P<0.05).

CONCLUSIONST2DM patients have decreased subcortical white matter of multiple brain regions, and the atrophy of subcortical white matter can be improved by the insulin therapy. The volume analysis of subcortical white matter is a simple and effective tool for the evaluation of white matter damage in T2DM patients.

Aged ; Case-Control Studies ; Corpus Callosum ; pathology ; Diabetes Mellitus, Type 2 ; pathology ; Female ; Humans ; Image Processing, Computer-Assisted ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Plethysmography