Does the pleth variability index have any predictive value for intraoperative respiratory problems in bariatric surgery?

Background/aim: We aimed to search the relationship between the preoperative PVI (pleth variability index) and intraoperative respiratory parameters to reveal whether PVI can be used as a prediction tool in bariatric surgery. Materials and methods: Forty patients undergoing bariatric surgery were included. Noninvasive pleth variability index measured via finger probe before induction of general anesthesia. Following intubation each patient was ventilated in controlled mode. Intraoperative blood pressure, peak airway pressure, end-tidal CO2, SpO2, PEEP, and FiO2 were recorded every 5 min for the first 10 min and then every 10 min until extubation. Steroid and bronchodilator requirements were recorded. Results: The systolic pressure-PVI, oxygen saturation-PVI relationship was statistically significant (p = 0.03, p = 0.013). A relationship was found between pleth variability index and peak airway pressure (p = 0.002). No correlation was detected between end-tidal CO2 and pleth variability index. The relationship between steroid, bronchodilator use, and PVI was significant (p = 0.05, p = 0.01). A positive correlation between PEEP and PVI was detected at varying time points. A positive correlation was found between FiO2-PVI. Conclusion: A relationship was found between PVI and intraoperative peak airway pressures, oxygen saturation, PEEP, bronchodilatator, and steroid usage. This result may be inspiring to conduct larger studies addressing the issue of predicting intraoperative respiratory problems in bariatric surgeries.

Lung Function Evaluated By Structured Light Plethysmography in Children After Lung Surgery: A Preliminary Analysis.

Background: Structured light plethysmography (SLP) is a novel light-based method that captures chest wall movements to evaluate tidal breathing. Methods: Thirty-two children who underwent lung surgery were enrolled. Their clinical history was collected along with spirometry and SLP. Results: Median age of surgery was 9 months (interquartile range 4-30). Most frequent diagnosis was congenital pulmonary airway malformation (14/32), then pulmonary sequestration (9/32), tumor (5/32), and bronchogenic cyst (4/32). The most frequent surgical approach was lobectomy (59%), segmentectomy (38%), and complete resection (3%). More than 80% had surgery when younger than 3 years of age. Eight patients had short-term complications (pleural effusion was the most frequent), while long-term effects were reported in 15 patients (19% recurrent cough, 13% thoracic deformities, 13% airway infections, 9% wheezing, 6% reduced exercise tolerance, and 3% columnar deformities). Spirometry was normal in 9/22 patients. Nine patients had a restrictive pattern, while 4 showed a mild bronco-reactivity. Ten patients did not perform spirometry because of young age. SLP revealed the presence of obstructive pattern in 10% of patients (IE50 > 1.88) and showed a significant difference between the two hemithorax in 29% of patients. Discussion: SLP may be a new method to evaluate lung function, without collaboration and radiation exposure, in children who underwent lung resection, also in preschool age.

Goal-directed fluid therapy guided by plethysmographic variability index versus conventional liberal fluid therapy in neonates undergoing abdominal surgery: A prospective randomized controlled trial.

BACKGROUND: Intraoperative fluid therapy maintains normovolemia, normal tissue perfusion, normal metabolic function, normal electrolytes, and acid-base status. Plethysmographic variability index has been shown to predict fluid responsiveness but its role in guiding intraoperative fluid therapy is still elusive. AIMS: The aim of the present study was to compare intraoperative goal-directed fluid therapy based on plethysmographic variability index with liberal fluid therapy in term neonates undergoing abdominal surgeries. METHODS: A prospective randomized controlled study was conducted in a tertiary care centre, over a period of 18 months. A total of 30 neonates completed the study out of 132 neonates screened. Neonates with tracheoesophageal fistula, congenital diaphragmatic hernia, congenital heart disease, respiratory disorders, creatinine clearance <90 mL/min and who were hemodynamically unstable were excluded. Neonates were randomized to goal-directed fluid therapy group where the plethysmographic variability index was targeted at <18 or liberal fluid therapy group. Primary outcome was comparison of total amount of fluid infused intraoperatively in both the groups. Secondary outcomes included intraoperative and postoperative arterial blood gas parameters, biochemical parameters, use of vasopressors, number of fluid boluses, complications and duration of hospital stay. RESULTS: There was no significant difference in total intraoperative fluid infused [90 (84-117.5 mL) in goal-directed fluid therapy and 105 (85.5-144.5 mL) in liberal fluid therapy group (p = .406)], median difference (95% CI) -15 (-49.1 to 19.1). There was a decrease in serum lactate levels in both groups from preoperative to postoperative 24 h. The amount of fluid infused before dopamine administration was significantly higher in liberal fluid therapy group (58 [50.25-65 mL]) compared to goal-directed fluid therapy group (36 [22-44 mL], p = .008), median difference (95% CI) -22 (-46 to 2). In postoperative period, the total amount of fluid intake over 24 h was comparable in two groups (222 [204-253 mL] in goal-directed fluid therapy group and 224 [179.5-289.5 mL] in liberal fluid therapy group, p = .917) median difference (95% CI) cutoff -2 (-65.3 to 61.2). CONCLUSION: Intraoperative plethysmographic variability index-guided goal-directed fluid therapy was comparable to liberal fluid therapy in terms of total volume of fluid infused in neonates during perioperative period. More randomized controlled trials with higher sample size are required. TRIAL REGISTRATION: Central Trial Registry of India (CTRI/2020/02/023561).

Bridging vascular physiology to vascular medicine: an integrative laboratory class.

Vascular diseases of the legs are highly prevalent and constitute an important part of medical curricula. The understanding of these diseases relies on strongly interwoven aspects of vascular physiology and vascular medicine. We aimed to connect these within a horizontally integrated laboratory class on vascular physiology of the leg that was designed in cooperation between the departments of physiology and vascular surgery. Conceptually, we applied examination techniques of vascular medicine to visualize physiological parameters that are altered by the most frequent diseases. This facilitates integrative discussions on malfunctions, trains diagnostic skills, and bridges to vascular medicine. In four experiments, we use oscillometry and impedance venous occlusion plethysmography to address key aspects of the arterial and venous system of the legs: 1) arterial pulse wave, 2) arterial systolic blood pressure, 3) venous capacitance and venous outflow, and 4) reactive hyperemia. After the experiments, physiological vascular function, the associated diseases, their impact on the recorded parameters, and diagnostic options are discussed. To allow reproduction, we describe the course structure and the experimental setup in detail. We present the experimental data of a cohort of medical students and document learning success and student satisfaction. All experiments were feasible and provided robust data on physiologically and clinically relevant vascular functions. The activity was perceived positively by the students and led to a substantial improvement of knowledge. With this work, we offer a template for reproduction or variation of a proven concept of horizontally integrated teaching of vascular physiology of the leg.NEW & NOTEWORTHY This article presents an integrative laboratory class on vascular physiology bridging to vascular medicine. The four experiments rely on oscillometry and venous occlusion plethysmography. We describe in detail this new class regarding structure, experimental setup, and experimental procedure, and we give insight into the applied materials. Moreover, we present the experimental data of 74 students and a quantitative evaluation of the students' learning success and acceptance.

The Association Between Lung Hyperinflation and Coronary Artery Disease in Smokers.

BACKGROUND: Smokers manifest varied phenotypes of pulmonary impairment. RESEARCH QUESTION: Which pulmonary phenotypes are associated with coronary artery disease (CAD) in smokers? STUDY DESIGN AND METHODS: We analyzed data from the University of Pittsburgh COPD Specialized Center for Clinically Oriented Research (SCCOR) cohort (n = 481) and the Genetic Epidemiology of COPD (COPDGene) cohort (n = 2,580). Participants were current and former smokers with > 10 pack-years of tobacco exposure. Data from the two cohorts were analyzed separately because of methodologic differences. Lung hyperinflation was assessed by plethysmography in the SCCOR cohort and by inspiratory and expiratory CT scan lung volumes in the COPDGene cohort. Subclinical CAD was assessed as the coronary artery calcium score, whereas clinical CAD was defined as a self-reported history of CAD or myocardial infarction (MI). Analyses were performed in all smokers and then repeated in those with airflow obstruction (FEV1 to FVC ratio, < 0.70). RESULTS: Pulmonary phenotypes, including airflow limitation, emphysema, lung hyperinflation, diffusion capacity, and radiographic measures of airway remodeling, showed weak to moderate correlations (r < 0.7) with each other. In multivariate models adjusted for pulmonary phenotypes and CAD risk factors, lung hyperinflation was the only phenotype associated with calcium score, history of clinical CAD, or history of MI (per 0.2 higher expiratory and inspiratory CT scan lung volume; coronary calcium: OR, 1.2; 95% CI, 1.1-1.5; P = .02; clinical CAD: OR, 1.6; 95% CI, 1.1-2.3; P = .01; and MI in COPDGene: OR, 1.7; 95% CI, 1.0-2.8; P = .05). FEV1 and emphysema were associated with increased risk of CAD (P < .05) in models adjusted for CAD risk factors; however, these associations were attenuated on adjusting for lung hyperinflation. Results were the same in those with airflow obstruction and were present in both cohorts. INTERPRETATION: Lung hyperinflation is associated strongly with clinical and subclinical CAD in smokers, including those with airflow obstruction. After lung hyperinflation was accounted for, FEV1 and emphysema no longer were associated with CAD. Subsequent studies should consider measuring lung hyperinflation and examining its mechanistic role in CAD in current and former smokers.

Feasibility of structured light Plethysmography (SLP) in patients with coronavirus disease 2019 (COVID-19).

As a result of the COVID-19 pandemic, most institutions have changed the way patients are assessed or investigated. Using novel non-contact technology, it is possible to continuously monitor the lung function of peri-operative patients undergoing cardiothoracic procedures. Primarily, this results in increased patient surveillance, and therefore, safety. Many centres, globally, are starting to use structured light plethysmography (SLP) technology, providing a non-aerosol generating procedure in place of traditional spirometry. While more evidence is needed, our clinical usage; previous and on-going studies; demonstrate definite potential that SLP is a valuable tool.

Modelos preditivos da composição corporal de neonatos e lactentes / Predictive models of body composition in neonates and infants

Objetivos: Analisar os modelos preditivos desenvolvidos para avaliação da massa livre de gordura e de gordura em neonatos e desenvolver modelos preditivos da massa de gordura corporal para neonatos e lactentes. Métodos: A primeira fase da dissertação trata se de uma revisão sistemática de artigos que desenvolveram modelos preditivos da composição corporal de neonatos, tendo como teste de referência a pletismografia por deslocamento de ar. Os estudos selecionados foram identificados nas bases de dados Pubmed/MEDLINE, Biblioteca Virtual em Saúde (BVS) e ScienceDirect. Os estudos foram selecionados de acordo com o relatório TRIPOD e a avaliação de risco de viés dos estudos através da ferramenta PROBAST. Para a segunda fase do presente trabalho, foi realizado o desenvolvimento de modelos preditivos da massa de gordura corporal de 125 neonatos (entre 1 e 5 dias de idade) e 71 lactentes (≥ 3 meses até 6 meses de idade). O método de stepwise foi utilizado para estimar o modelo final a partir dos preditores sexo, peso, comprimento, dobra cutânea tricipital, circunferência abdominal, circunferência média de braço e idade gestacional. O erro quadrado médio foi utilizado para avaliação do desempenho e o teste t para comparação entre os valores previstos pelo modelo de desenvolvimento e validação. Resultados: Foram incluídos na primeira fase quatro estudos, dos quais todos apresentaram o peso como preditor da composição corporal neonatal e três estudos utilizaram a soma de diferentes dobras cutâneas para predizer a gordura corporal neonatal. Apenas dois modelos, que utilizaram dobras cutâneas, explicaram significativamente 81% da gordura corporal, enquanto os modelos que utilizaram a bioimpedância não encontraram correlação significativa entre o índice de impedância e a massa livre de gordura. Na segunda fase da presente dissertação, dentre os preditores testados, o sexo, o peso e a dobra cutânea tricipital foram os que compuseram ambos os modelos. Para neonatos, o modelo (-0,76638 + 0,00025 * peso atual (g)+ 0,06199 * prega cutânea tricipital (mm) + 0,07545 * sexo) explicou cerca de 70% da massa de gordura corporal e para lactentes (-2,22748 + * 0,00049 * peso atual (g) + * 0,07375 * prega cutânea tricipital (mm) + 0,246478 * sexo), explicou 84%. Conclusão: Os estudos sobre essa temática são escassos e apresentam inúmeras diferenças metodológicas, principalmente em relação aos preditores da massa de gordura corporal. O presente trabalho desenvolveu modelos capazes de estimar a massa de gordura corporal de neonatos e lactentes nascidos a termo, podendo ser utilizados na prática clínica em grupos com perfil semelhante.

Individualized Fluid Management Using the Pleth Variability Index: A Randomized Clinical Trial.

BACKGROUND: The present trial was designed to assess whether individualized strategies of fluid administration using a noninvasive plethysmographic variability index could reduce the postoperative hospital length of stay and morbidity after intermediate-risk surgery. METHODS: This was a multicenter, randomized, nonblinded parallel-group clinical trial conducted in five hospitals. Adult patients in sinus rhythm having elective orthopedic surgery (knee or hip arthroplasty) under general anesthesia were enrolled. Individualized hemodynamic management aimed to achieve a plethysmographic variability index under 13%, and the standard management strategy aimed to maintain a mean arterial pressure above 65 mmHg during general anesthesia. The primary outcome was the postoperative hospital length of stay decided by surgeons blinded to the group allocation of the patient. RESULTS: In total, 447 patients were randomized, and 438 were included in the analysis. The mean hospital length of stay ± SD was 6 ± 3 days for the plethysmographic variability index group and 6 ± 3 days for the control group (adjusted difference, 0.0 days; 95% CI, -0.6 to 0.5; P = 0.860); the theoretical postoperative hospital length of stay was 4 ± 2 days for the plethysmographic variability index group and 4 ± 1 days for the control group (P = 0.238). In the plethysmographic variability index and control groups, serious postoperative cardiac complications occurred in 3 of 217 (1%) and 2 of 224 (1%) patients (P = 0.681), acute postoperative renal failure occurred in 9 (4%) and 8 (4%) patients (P = 0.808), the troponin Ic concentration was more than 0.06 µg/l within 5 days postoperatively for 6 (3%) and 5 (2%) patients (P = 0.768), and the postoperative arterial lactate measurements were 1.44 ± 1.01 and 1.43 ± 0.95 mmol/l (P = 0.974), respectively. CONCLUSIONS: Among intermediate-risk patients having orthopedic surgery with general anesthesia, fluid administration guided by the plethysmographic variability index did not shorten the duration of hospitalization or reduce complications.

Mini-fluid challenge test predicts stroke volume and arterial pressure fluid responsiveness during spine surgery in prone position: A STARD-compliant diagnostic accuracy study.

The study was designed to verify if mini-fluid challenge test is more reliable than dynamic fluid variables in predicting stroke volume (SV) and arterial pressure fluid responsiveness during spine surgery in prone position with low-tidal-volume ventilation.Fifty patients undergoing spine surgery in prone position were included. Fluid challenge with 500 mL of colloid over 15 minutes was given. Changes in SV and systolic blood pressure (SBP) after initial 100 mL were compared with SV, pulse pressure variation (PPV), SV variation (SVV), plethysmographic variability index (PVI), and dynamic arterial elastance (Eadyn) in predicting SV or arterial pressure fluid responsiveness (15% increase or greater).An increase in SV of 5% or more after 100 mL predicted SV fluid responsiveness with area under the receiver operating curve (AUROC) of 0.90 (95% confidence interval [CI], 0.82 to 0.99), which was significantly higher than that of PPV (0.71 [95% CI, 0.57 to 0.86]; P = .01), and SVV (0.72 [95% CI, 0.57 to 0.87]; P = .03). A more than 4% increase in SBP after 100 mL predicted arterial pressure fluid responsiveness with AUROC of 0.86 (95% CI, 0.71-1.00), which was significantly higher than that of Eadyn (0.52 [95% CI, 0.33 to 0.71]; P = .01).Changes in SV and SBP after 100 mL of colloid predicted SV and arterial pressure fluid responsiveness, respectively, during spine surgery in prone position with low-tidal-volume ventilation.

Body composition among long distance runners

SUMMARY OBJECTIVE The current study aimed to examine the body composition of adult male ultra-trail runners (UTR) according to their level of participation (regional UTR-R, vs. national UTR-N). METHODS The sample was composed of 44 adult male UTR (aged 36.5±7.2 years; UTR-R: n=25; UTR-N: n=19). Body composition was assessed by air displacement plethysmography, bioelectrical impedance, and dual-energy X-ray absorptiometry. In addition, the Food Frequency Questionnaire (FFQ) was applied. A comparison between the groups was performed using independent samples t-test. RESULTS Significant differences between groups contrasting in the competitive level were found for chronological age (in years; UTR-R: 38.8±8.2 vs. UTR-N: 33.5±4.1); body density (in L.kg-1; UTR-R: 1.062±0.015 vs. UTR-N: 1.074±0.009); and fat mass (in kg; UTR-R: 12.7±6.8 vs. UTR-N: 7.6±2.7). CONCLUSION UTR-N were younger, presented higher values for body density, and had less fat mass, although no significant differences were found for fat-free mass. The current study evidenced the profile of long-distance runners and the need for weight management programs to regulate body composition.

RESUMO OBJETIVO O presente estudo objetivou examinar a composição corporal dos corredores de ultra-trail (UTR) e, adicionalmente, comparar dois grupos de acordo com o nível de participação (Regional vs. Nacional, respectivamente UTR-R e UTR-N). MÉTODOS A amostra foi composta por 44 corredores adultos masculinos (36,5±7,2 anos de idade; UTR-R: n=25; UTR-N: n=19). A composição corporal foi avaliada recorrendo à pletismografia de ar deslocado, bioimpedância elétrica e absorciometria de raios X de dupla energia. Adicionalmente, foi utilizado o Questionário de Frequência Alimentar. A comparação entre grupos foi realizada com base na prova t-student para amostras independentes. RESULTADOS Foram encontradas diferenças significativas por nível de competição para as seguintes variáveis dependentes: idade cronológica (em anos; UTR-R: 38,8±8,2 vs. UTR-N: 33,5±4,1); densidade corporal (em kg/L; UTR-R: 1,062±0,015 L/kg vs. UTR-N: 1,074±0,009); massa gorda (em kg; UTR-R: 12,7±6,8 kg vs. UTR-N: 7,6±2,7). CONCLUSÃO Os UTR-N tendem a ser mais jovens e apresentam valores superiores de densidade corporal e, consequentemente, valores menores de massa gorda, sendo a massa isenta de gordura semelhante entre os grupos. O presente estudo determinou o perfil dos corredores adultos masculinos de longa distância (ultra-trail), realçando a importância de uma cuidadosa regulação da massa corporal.

Continuous hemoglobin and plethysmography variability index monitoring can modify blood transfusion practice and is associated with lower mortality.

To determine the effect of implementing an algorithm of fluid and blood administration based on continuous monitoring of hemoglobin (SpHb) and PVI (plethysmography variability index) on mortality and transfusion on a whole hospital scale. This single-center quality program compared transfusion at 48 h and mortality at 30 days and 90 days after surgery between two 11-month periods in 2013 and 2014 during which all the operating and recovery rooms and intensive care units were equipped with SpHb/PVI monitors. The entire team was trained to use monitors and the algorithm. Team members were free to decide whether or not to use devices. Each device was connected to an electronic wireless acquired database to anonymously acquire parameters on-line and identify patients who received the monitoring. All data were available from electronic files. Patients were divided in three groups; 2013 (G1, n = 9285), 2014 without (G2, n = 5856) and with (G3, n = 3575) goal-directed therapy. The influence of age, ASA class, severity and urgency of surgery and use of algorithm on mortality and blood use were analyzed with cox-proportional hazard models. Because in 2015, SpHb/PVI monitors were no longer available, we assessed post-study mortality observed in 2015 to measure the impact of team training to adjust vascular filling on a patient to patient basis. During non-cardiac surgery, blood was more often transfused during surgery in G3 patients as compared to G2 (66.6% vs. 50.7%, p < 0.001) but with fewer blood units per patient. After adjustment, survival analysis showed a lower risk of transfusion at 48 h in G3 [OR 0.79 (0.68-0.93), p = 0.004] but not in G2 [OR 0.90 (0.78-1.04) p = 0.17] as compared to G1. When adjusting to the severity of surgery as covariable, there was 0.5 and 0.7% differences of mortality at day 30 and 90 whether patients had goal directed therapy (GDT). After high risk surgery, the mortality at day 30 is reduced by 4% when using GDT, and 1% after intermediate risk surgery. There was no difference for low risk surgery. G3 Patients had a lower risk of death at 30 days post-surgery [OR 0.67 (0.49-0.92) p = 0.01] but not G2 patients [OR 1.01, (0.78-1.29), p = 0.96]. In 2015, mortality at 30 days and 90 days increased again to similar levels as those of 2013, respectively 2.18 and 3.09%. Monitoring SpHb and PVI integrated in a vascular filling algorithm is associated with earlier transfusion and reduced 30 and 90-day mortality on a whole hospital scale.

Pulse Pressure Variations and Plethysmographic Variability Index Measured at Ear Are Able to Predict Fluid Responsiveness in the Sitting Position for Neurosurgery.

BACKGROUND: Pulse pressure variation (PPV) and plethysmographic variability index (PVI), dynamic indicators of preload dependence based on heart-lung interactions, are used to predict fluid responsiveness in mechanically ventilated patients in the supine position. The sitting position for neurosurgery, by changing intrathoracic blood volume, could affect the capacity of PPV and PVI to predict fluid responsiveness. The aim of the study was to assess the ability of PPV and PVI to predict fluid responsiveness during general anesthesia in the sitting position. METHODS: In total, 31 patients were included after settling in the sitting position but before surgery began. PPV, PVI with a finger sensor (PVI finger), and PVI with an ear sensor (PVI ear) were recorded before and after a fluid challenge of hydroxylethylstarch 250 mL over 10 minute. Esophageal Doppler was used to record stroke volume. Patients were defined as fluid responders if stroke volume increased by more than 10% after the fluid challenge. RESULTS: In total, 13 (42%) patients were fluid responders. PPV and PVI ear were higher in responders than in nonresponders before the fluid challenge (12±5 vs. 7±3; P=0.0005 and 14±5 vs. 8±3; P=0.001, respectively). Areas under the receiver-operating curves to predict fluid responsiveness were 0.87 for PPV (P<0.0001), 0.87 for PVI ear (P<0.0001), and 0.64 for PVI finger (P=0.17). PPV ≥8% or PVI ear ≥11% predicted fluid responsiveness with sensitivities of 83% for both, and specificities of 83% and 91%, respectively. However PVI ear data were not available in 26% of patients. CONCLUSIONS: PPV can be used to predict fluid responsiveness in the sitting position for neurosurgery.

Effectiveness of smoking cessation in smokers with COPD and nocturnal oxygen desaturation: Functional analysis.

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is the fourth cause of mortality and it's frequently associated with breathing sleep disorders. OBJECTIVE: The aim of the study is to point out the benefit of smoking cessation over three months in terms of improvement of respiratory functional variables. METHODS: A retrospective analysis was performed evaluating the impact of smoking cessation on 145 patients with COPD and nocturnal oxygen desaturation. For this purpose, for all patients, overnight pulse oxymetry detection on room air, arterial blood sampling, plethysmography and exhaled test for carbon monoxide were performed at baseline and 3 months after the beginning. Smoking cessation was achieved by varenicline plus individual counselling. RESULTS: About 51% of patients quit smoking which was established by exhaledcarbon monoxide (eCO) measure (cut-off 5 ppm). Patients who quit smoking displayed notably better results compared with patients who did not. The eCO significantly decreased by 16 ppm versus 4 (P = 0.01), oxygen desaturation index (ODI) was reduced by 3 points versus 0.8 (P = 0.01) and forced expiratory in 1 second volume increased by 7% of predicted value versus 1% (P = 0.01). The walking test was improved by 102 m versus 25 in sustainers (P = 0.01). The CAT score was also improved by 10 versus 8 in sustainers (P = 0.01) and PaO2 increased by 5 mm Hg versus 0.5 (P = 0.04). The percentage of SaO2 < 90% was improved by 6.7 versus 2.1 (P = 0.04).The logistic regression analysis displayed the possible influence of CAT (P = 0.02) and modified medical research council dyspnea test (P = 0.05) on ODI value. CONCLUSIONS: Smoking cessation notably improves pulmonary functional parameters in quitters reporting nocturnal oxygen desaturation.

A Comparison of the Effects of Roux-en-Y Gastric Bypass and Sleeve Gastrectomy on Body Mass Composition as Measured by Air Displacement Plethysmography.

BACKGROUND: The laparoscopic sleeve gastrectomy (LSG) is now the most commonly performed bariatric surgery in the world. Multiple studies have demonstrated the equivalence between the LSG and Roux-en-Y gastric bypass (RYGB) with regard to weight loss and comorbidity resolution. Few studies have examined the differences in body mass composition change between the two procedures. METHODS: Sixty-three patients undergoing either LSG or RYGB underwent calculation of total body mass, ideal body mass, lean mass, and fat mass by air displacement plethysmography (BodPodtm) prior to surgery and at 12 months postoperatively. Calculations of excess body weight, % excess weight loss, change in % fat mass, and change in % lean mass were then performed at each time interval. RESULTS: Thirty-three patients underwent LSG and 30 patients underwent RYGB. Mean percent excess weight loss in the LSG and RYGB group was 47.2% and 53.4% respectively (p = 0.165, 95% CI - 14.8-2.6). Mean percent change in fat mass for the LSG group and RYGB group was 9.2% and 10.51% respectively (p = 0.249, 95% CI - 0.86-3.2). Mean percent change in lean mass for the LSG group and RYGB group was 9.4% and 10.49% respectively (p = 0.383, 95% CI 2.85-1.13). CONCLUSION: The LSG and RYGB both impart dramatic meaningful loss in excess body weight. In addition, both the LSG and RYGB impart dramatic reductions in fat mass. However, both procedures induce loss of lean mass and there appears to be no difference between the two procedures in this regard despite their anatomic and physiologic differences.

Endothelial Function Assessed by Digital Volume Plethysmography Predicts the Development and Progression of Type 2 Diabetes Mellitus.

Background Endothelial dysfunction is a consequence of type 2 diabetes mellitus, but it is unclear whether endothelial dysfunction of conductance versus resistance vessels may also precede type 2 diabetes mellitus development. Methods and Results In a population-based cohort of 15 010 individuals from the GHS (Gutenberg Health Study) (aged 35-74 years at enrollment in 2007-2012), we identified 1610 cases of incident pre-diabetes mellitus and 386 cases of incident type 2 diabetes mellitus by hemoglobin A1c (HbA1c) and/or medical history between 2012 and 2017. Endothelial function of conductance and resistance vessels was measured by flow-mediated dilation and digital volume plethysmography-derived reactive hyperemia index, respectively. Multivariable regression modeling was used to estimate ß coefficients of HbA1c levels at follow-up and relative risks of incident (pre-)diabetes mellitus. Reactive hyperemia index was independently associated with HbA1c after multivariable adjustment for baseline HbA1c, sex, age, socioeconomic status, arterial hypertension, waist/height ratio, pack-years of smoking, non-high-density lipoprotein/high-density lipoprotein ratio, physical activity, family history of myocardial infarction/stroke, prevalent cardiovascular disease, medication use, and C-reactive protein (ß=-0.020; P=0.0029). The adjusted relative risk per SD decline in reactive hyperemia index was 1.08 (95% CI, 1.02-1.15; P=0.012) for incident pre-diabetes mellitus and 1.16 (95% CI, 1.01-1.34; P=0.041) for incident type 2 diabetes mellitus. Flow-mediated dilation independently increased the relative risk for developing pre-diabetes mellitus by 8% (95% CI, 1.02-1.14; P=0.012), but it was not independently associated with incident type 2 diabetes mellitus (relative risk, 1.01; 95% CI, 0.86-1.19; P=0.92) and with HbA1c (ß=-0.003; P=0.59). Conclusions Endothelial dysfunction of resistance rather than conductance vessels may precede the development of (pre-)diabetes mellitus. Assessment of endothelial function by digital volume plethysmography may help to identify subjects at risk for development of type 2 diabetes mellitus.

The impact of weight loss beyond lung function: benefit with respect to asthma outcomes.

OBJECTIVE: We evaluated the effect of weight loss (WL) on lung function (LF) in obese individuals who underwent bariatric surgery, and on asthma control, quality of life, LF, and controller medication in a sub-group of obese asthma (OA) patients. MATERIALS AND METHODS: Obese individuals who underwent bariatric surgery between July 2015 and July 2017 were included in this prospective longitudinal study. They were classified as OA or obese non-asthmatics (O-NA). LF was assessed preoperatively and 6-9 months postoperatively. In OA patients, asthma control, quality of life, and treatment step were evaluated. P < 0.05 was considered significant. RESULTS: Twenty-six patients (OA: n = 8; O-NA: n = 18), 84.6% with class III obesity were enrolled. Preoperatively, OA patients showed worse values of LF parameters, with upper and lower airway CARAT scores of 6.1 ±â€¯3.1 and 13.4 ±â€¯4.1, respectively, and 75% were in step 4 of treatment. After WL, improvements in dynamic volumes, lung capacities, and total resistance were observed in both groups. Despite greater increases in OA patients, no significant differences were observed between groups. In OA patients, improvements in CARAT score of upper (3.9 ±â€¯1.9, p = 0.017) and lower (4.2 ±â€¯4.4, p = 0.027) airways, and in Asthma Life Quality scores (8.1 ±â€¯5.6, p = 0.017) were observed along with a decrease (-1.8 ±â€¯1.0, p = 0.017) in treatment step. CONCLUSIONS: All LF parameters improved after WL. Although the improvement was greater in OA patients, the difference between groups was not significant. Significant improvement from baseline in uncontrolled symptoms of OA patients and quality of life was observed after WL, along with a significant decrease in treatment step.

Comparison of bioelectrical impedance analysis and air displacement plethysmography / Comparación de análisis de impedancia bioeléctrica y pletismografía de desplazamiento de aire

The measurement of body composition has become an important component in the diagnosis of health, physical conditioning and nutritional status. The aim of this study was to compare two methods of detecting body composition, bioelectrical impedance and air displacement plethysmography for athletes and non-athletes. Specifically, we compared the parameters as fat mass, fat free mass and the value of basal metabolic rate. A sample size of 52 men (age 26.2 ± 5.4 years) that included a group of mixed martial arts (MMA) fighters (n = 31, age 27.2 ± 5.5 years) and a group of the non-athletes (n =21, age 24.6 ± 5.1 years). Both groups were measured by bioelectrical impedance and air displacement plethysmography. Significant differences in % body fat (p<0.05) and fat-free mass (p<0.05) were noted between bioelectrical impedance and air displacement plethysmography of non-athletes, but there were no significant differences for athletes. Furthermore, there was a significant difference (p<0.001) of basal metabolic rate between bioelectrical impedance and air displacement plethysmography, but the correlation with fat free mass was very strong for both methods. Therefore, the use of bioelectrical impedance and air displacement plethysmography may be useful for detecting changes in body composition, but their accuracy is controversial and for this reason we recommend using only one method and not combining them.

La medición de la composición corporal se ha convertido en un componente importante en el diagnóstico de la salud, el acondicionamiento físico y el estado nutricional. El objetivo de este estudio fue comparar dos métodos para detectar la composición corporal, la impedancia bioeléctrica y la pletismografía de desplazamiento de aire para atletas y no atletas. Específicamente, comparamos los parámetros como masa grasa, masa libre de grasa y el valor de la tasa metabólica basal. Un tamaño de muestra de 52 hombres (edad 26,2 ± 5,4 años) de un grupo de luchadores de artes marciales mixtas (MMA) (n = 31, edad 27,2 ± 5,5 años) y un grupo de no deportistas (n = 21, edad 24,6 ± 5,1 años). Ambos grupos se midieron por impedancia bioeléctrica y pletismografía de desplazamiento de aire. Se observaron diferencias significativas en el porcentaje de grasa corporal (p<0,05) y la masa libre de grasa (p<0,05) entre la impedancia bioeléctrica y la pletismografía de desplazamiento de aire de los no deportistas, sin embargo no hubo diferencias significativas en los atletas. Además, se observó una diferencia significativa (p<0,001) de la tasa metabólica basal entre la impedancia bioeléctrica y la pletismografía de desplazamiento de aire, pero la correlación con la masa libre de grasa fue importante para ambos métodos. Por lo tanto, el uso de la pletismografía de impedancia bioeléctrica y desplazamiento de aire puede ser útil para detectar cambios en la composición corporal, pero su precisión es controvertida por lo que recomendamos usar solo un método y no una combinación de ambos.

Physical fitness and activity, metabolic profile, adipokines and endothelial function in children / Aptidão e atividade física, perfil metabólico, adipocinas e função endotelial em crianças

Abstract Objectives: The prevalence of obesity is increasing. The aim of this study was to investigate if there is endothelial dysfunction in children with normal or excess weight, and whether the metabolic profile, adipokines, and endothelial dysfunction would be more strongly associated with physical fitness or with physical activity levels. Method: Cross-sectional study involving children aged 5-12 years. The evaluation included venous occlusion plethysmography, serum levels of adiponectin, leptin and insulin, lipid profile, physical activity score (PAQ-C questionnaire), and physical fitness evaluation (Yo-Yo test). Results: A total of 62 children participated in this study. Based on the body mass index, 27 were eutrophic, 10 overweight and 25 obese. Triglycerides, LDL cholesterol, HOMA-IR, and leptin were higher in the obese and excess-weight groups compared to the eutrophic group (p < 0.01). HDL cholesterol and adiponectin levels were higher in the eutrophic group compared to the obese and excess-weight groups (p < 0.01). Flow-mediated vasodilation after hyperemia was higher in the eutrophic group in comparison to obese and excess-weight subjects (p < 0.05). There was no difference in the physical activity levels among groups measured by PAQ-C. The Yo-Yo test was significantly associated with HDL cholesterol (rho = −0.41; p = 0.01), and this association remained after adjusting for body mass index z-score (rho = 0.28; p = 0.03). Conclusion: This study showed that endothelial dysfunction is already present in obese children, suggesting a predisposition to atherosclerotic disease. Moreover, HDL cholesterol levels were correlated with physical fitness, regardless of body mass index.

Resumo: Objetivos: A prevalência da obesidade está aumentando. O objetivo deste estudo foi investigar se há disfunção endotelial nas crianças com peso normal ou excesso de peso e se o perfil metabólico, as adipocinas e a disfunção endotelial seriam mais fortemente associados à aptidão física ou aos níveis de atividade física. Método: Estudo transversal que envolve crianças de 5-12 anos. A avaliação incluiu pletismografia de oclusão venosa, níveis séricos de adiponectina, leptina, insulina e lipidograma, escore de atividade física (questionário PAQ-C) e avaliação da aptidão física (teste Yo-yo). Resultados: Um total de 62 crianças participou deste estudo. Com base no índice de massa corporal, 27 eram eutróficos, 10 estavam acima do peso e 25 estavam obesos. Os níveis de triglicerídeos, colesterol LDL, HOMA-RI e leptina estavam mais elevados nas crianças obesas e com excesso de peso que o grupo de eutróficos (p < 0,01). Os níveis de colesterol HDL e adiponectina estavam mais elevados no grupo de eutróficos em comparação ao grupo de obesos e com excesso de peso (p < 0,01). A vasodilatação mediada pelo fluxo após hiperemia foi maior no grupo de eutróficos em comparação aos indivíduos obesos e com excesso de peso (p < 0,05). Não houve nenhuma diferença nos níveis de atividade física entre os grupos medidos pelo PAQ-C. O teste de ida e volta foi significativamente associado ao colesterol HDL (ró = −0,41; p = 0,01) e essa associação continuou após ajustar o escore z do índice de massa corporal (ró = 0,28; p = 0,03). Conclusão: Este estudo mostrou que a disfunção endotelial já está presente nas crianças obesas, sugeriu uma predisposição à doença aterosclerótica. Além disso, os níveis de colesterol HDL foram correlacionados à aptidão física, independentemente do índice de massa corporal.

Comparison of pulse pressure variation and pleth variability index in the prone position in pediatric patients under 2 years old.

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.

Comparison of Forced and Slow Vital Capacity Maneuvers in Defining Airway Obstruction.

BACKGROUND: Obstructive lung disease is diagnosed by a decreased ratio of FEV1 to the vital capacity (VC). Although the most commonly used VC is FVC, American Thoracic Society guidelines suggest alternative VCs, for example, slow VC (SVC), may offer a more-accurate evaluation of breathing capacity. There is recent evidence that using only FEV1/FVC underrecognizes obstruction in subjects at high risk and who are symptomatic. Previous studies have indicated that healthy individuals show a minimum difference between FVC and SVC; however, testing of individuals with asthma and who are symptomatic indicates that SVC can be markedly larger than FVC. OBJECTIVE: To evaluate the differences among SVC, FVC, and SVC-based measurements in the diagnosis of symptomatic obstructive lung disease. METHODS: A retrospective analysis was performed of spirometry and plethysmography measurements from studies conducted between 2011 to 2015. We established a pulmonary function database that incorporated predictive equations from the National Health and Nutrition Examination Survey III (NHANES III). The SVC to FVC difference was calculated. FEV1/SVC was compared with FEV1/FVC by using NHANES III lower limit of normal values. RESULTS: A total of 2,710 studies with 2,244 subjects were reviewed. Spirometric obstruction, as defined by NHANES III, was identified in 26.1% of the studies (707/2,710). The mean (± SD) difference between SVC and FVC was 375.0 ± 623.0 mL and 258.8 ± 532.5 mL in those with and those without obstruction, respectively. Subgroup and multivariate analysis demonstrated age, body mass index, and FEV1 associated contributions to the difference between SVC and FVC. By using FEV1/SVC, the prevalence of obstruction increased from 26.1 to 45.0% (1,219/2,710) and identified 566 additional studies of subjects with obstruction. Fifty-four percent of the subjects with newly-identified obstructive lung disease (305/566) had smoking histories, and 67.4% (345/512) received medications for obstructive lung disease. CONCLUSIONS: The isolated use of FVC-based diagnostic algorithms did not recognize individuals with symptomatic obstructive lung disease. Recognizing the difference between SVC and FVC measurements in subjects will improve testing and diagnosis of obstructive lung disease.