The Role of the Diaphragm in Postural Stability and Visceral Function in Parkinson’s Disease

Background: In normal subjects, the diaphragm plays a key functional role in postural stability, articulation, respiration, defecation, and urination.Objectives: The aim of this study was to investigate the role of the diaphragm in postural stability and visceral function in patients with Parkinson’s disease (PD) and to compare the diaphragm function by gender, Hoehn and Yahr (H&Y) staging, and motor subtypes.Methods: In total, 79 patients were enrolled in this cross-sectional study. The severity of the disease was assessed by the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale III and by H&Y staging. Postural stability was quantitatively recorded, and respiratory function was evaluated by spirometry. Several scales were used to evaluate visceral function in patients with PD. In addition, diaphragm ultrasound was used to measure the excursion, contraction velocity, and thickness of the diaphragm during quiet breathing, deep breathing, and the sniff test. Significant features were selected by the least absolute shrinkage and selection operator (LASSO) regression and fitted in the multivariate linear regression and Pearson’s correlation analysis.Results: Diaphragm thickness and excursion during quiet breathing were significantly different between men and women and between H&Y stage 1–2 and stage 2.5–3, whereas the diaphragm function was not influenced by motor subtypes. It was shown that the diaphragmatic function was significantly correlated with postural stability, voice function, respiratory function, constipation, and urological function to varying degrees in patients with PD.Conclusion: The diaphragmatic function is associated with dysfunction in PD although it remains unclear as to whether the observed changes in the diaphragm are primary or secondary.

Prediction of Loss of Muscle Mass in Sarcopenia Using Ultrasonic Diaphragm Excursion

Background. The diagnosis of sarcopenia is based on the mass and function of appendicular skeletal muscle. It is not clear whether diaphragm excursion is related to muscle mass loss. We try to fill the gap by measuring ultrasonic diaphragm excursion during quiet breathing (Dq) and forced deep breathing (Df) and test whether they could predict the muscle mass loss in sarcopenia. Methods. The subjects are recruited from the elderly patients diagnosed with pulmonary nodules in community physical examination. According to the definition, the subjects were divided into group A (who did not meet the diagnostic criteria for muscle mass loss in sarcopenia) and group B (who met the criteria). Participants were assessed for ultrasonic diaphragm excursion, pulmonary function, and cardiopulmonary exercise testing. Logistic regression was used to assess the correlation between right diaphragm excursion and skeletal muscle mass, and receiver-operating characteristic curve (ROC) was applied to determine the best threshold. Results. We recruited 64 elderly participants: 52 in group A (39 males) and 12 in group B (8 males). The Df in group A were higher than in group B (6.02 (5.44–6.60) vs. 4.31 (3.53–5.09) cm, P = 0.008 ). The difference also exists in FVC, FEV1.0, PEF, Pimax, WRmax, and VO2max, but neither in Dq. Logical regression showed that Df was negatively related to muscle mass (B = −0.525, OR = 0.591 (0.378–0.926), P = 0.022 ), even after adjusted age. Based on ROC, a cutoff value of 5.27 cm (AUC = 0.7783, P = 0.0028 ) was selected, and Df ≤ 5.27 cm indicates the increase in odds of existing muscle mass loss. Conclusion. Ultrasonic diaphragm excursion in forced deep breath is helpful for predicting muscle mass loss in sarcopenia. The trial is registered with ChiCTR1800019742.

In Vitro Evaluation of a Nasal Interface Used to Improve Delivery from a Portable Oxygen Concentrator

Portable oxygen concentrators (POCs) are widely used to administer long-term oxygen therapy (LTOT) and employ pulsed delivery modes to conserve oxygen. Efficient pulsed delivery requires that POCs are triggered by patient inhalation. Triggering is known to fail for some patients during periods of quite breathing, as occurs during sleep. The present article describes a new nasal interface designed to improve triggering of pulsed oxygen delivery from portable oxygen concentrators (POCs). In vitro experiments incorporating realistic nasal airway replicas and simulated breathing were conducted. The pressure monitored via oxygen supply tubing (the signal pressure) was measured over a range of constant inhalation flow rates with the nasal interface inserted into the nares of the nasal airway replicas, and compared with signal pressures measured for standard and flared nasal cannulas. Triggering efficiency and the fraction of inhaled oxygen (FiO2) were then evaluated for the nasal interface and cannulas used with a commercial POC during simulated tidal breathing through the replicas. Higher signal pressures were achieved for the nasal interface than for nasal cannulas at all flow rates studied. The nasal interface triggered pulsed delivery from the POC in cases where nasal cannulas failed to trigger. FiO2 was significantly higher for successful triggering cases than for failed triggering cases. The nasal interface improved triggering of pulsed oxygen delivery from a POC and presents a simple solution that could be used with commercially-available POCs to reliably supply oxygen during periods of quiet breathing.

Artificial intelligence in the respiratory sounds analysis and computer diagnostics of bronchial asthma

Using a database containing audio files of respiratory sound records of asthmatic patients and healthy patients, a method of computer-aided diagnostics based on the machine learning technique creation of neural networks, has been developed. The database contains 952 records of respiratory sounds of asthma patients at different stages of the disease, aged from several months to 47 years, and 167 records of volunteers. Records were carried out with a quiet breathing at four points: in the oral cavity, above the trachea, on the chest, the second intercostal space on the right side, and at a point on the back. The developed method of computer-aided diagnostics allows diagnosing bronchial asthma with high reliability: sensitivity of 89.3%, specificity of 86%, accuracy of about 88% and Youden index of 0.753. The program learned once makes it possible to diagnose bronchial asthma with high reliability regardless of patient's gender and age, a stage of disease, as well as the point of sound recording. The developed method can be used as an additional screening method for the diagnostics of bronchial asthma and serve as the basis for development of computer control methods, including remote control (telemedicine) of patients condition and the effectiveness of the applied drugs in real time.

Peri-operative diaphragm ultrasound as a new method of recognizing post-operative residual curarization

Background This study sought to evaluate the diagnostic accuracy of peri-operative diaphragm ultrasound in assessing post-operative residual curarization (PORC). Methods Patients undergoing non-thoracic and non-abdominal surgery under general anaesthesia were enrolled from July 2019 to October 2019 at Peking Union Medical College Hospital. A train-of-four ratio (TOFr) lower than 0.9 was considered as the gold standard for PORC. Diaphragm ultrasound parameters included diaphragmatic excursion (DE) and diaphragm thickening fraction (DTF) during quiet breathing (QB) and deep breathing (DB). The diaphragm excursion fraction (DEF) was calculated as the DE-QB divided by the DE-DB. The diaphragm excursion difference (DED) was defined as DE-DB minus DE-QB. Receiver operating characteristic curve analysis was used to determine the cut-off values of ultrasound parameters for the prediction of PORC. Results In total, 75 patients were included, with a PORC incidence of 54.6%. The DE-DB and DED were positively correlated with the TOFr, while the DEF was negatively correlated with the TOFr. The DE-DB cut-off value for predicting PORC was 3.88 cm, with a sensitivity of 85.4% (95% confidence interval [CI]: 70.1–93.9%), specificity of 64.7% (95% CI: 46.4–79.7%), positive likelihood ratio of 2.42 (95% CI 1.5–3.9), and negative likelihood ratio of 0.23 (95% CI: 0.1–0.5). The DED cut-off value was 1.5 cm, with a specificity of 94.2% (95% CI: 80.3–99.3%), sensitivity of 63.4% (95% CI: 46.9–77.9%), positive likelihood ratio of 10.78 (95% CI: 2.8–42.2), and negative likelihood ratio of 0.39 (95% CI: 0.3–0.6). Conclusions Peri-operative diaphragm ultrasound may be an additional method aiding the recognition of PORC, with DED having high specificity.

Ultrasound Assessment of Diaphragm Thickness and Thickening: Reference Values and Limits of Normality When in a Seated Position

Background: Diagnosing diaphragm dysfunction in the absence of complete paralysis remains difficult. The aim of the present study was to assess the normal values of the thickness and the inspiratory thickening of both hemidiaphragms as measured by ultrasonography in healthy volunteers while in a seated position.Methods: Healthy volunteers with a normal pulmonary function test were recruited. The diaphragmatic thickness was measured on both sides at the zone of apposition of the diaphragm to the rib cage during quiet breathing at end-expiration, end-inspiration, and after maximal inspiration. The thickening ratio, the thickening fraction, and the thickness at end-inspiration divided by the thickness at deep breathing were determined. The mean values and the lower and upper limits of normal were determined for men and women.Results: 200 healthy volunteers (100 men and 100 women) were included in the study. The statistical analysis revealed that women had a thinner hemidiaphragm than men on both sides and at the various breathing times studied. The lower limit of normality of the diaphragm thickness measured at end-expiration was estimated to be 1.3 mm in men and 1.1 mm in women, on both sides. The thickening fraction did not differ significantly between men and women. In men, it ranged from 60 to 260% on the left side and from 57 to 200% on the right side. In women, it ranged from 58 to 264% on the left side and from 60 to 229% on the right side. The lower limits of normality of the thickening fraction were determined to be 40 and 39% in men and 39 and 48% in women for the right and left hemidiaphragms, respectively. The upper limit for normal of the mean of both sides of the ratio thickness at end-inspiration divided by the thickness at deep breathing was determined to be 0.78 in women and 0.79 in men.Conclusion: The normal values of thickness and the indexes of diaphragmatic function should help clinicians with detecting diaphragm atrophy and dysfunction.

Study of Ventricular Interdependence in Hemodialysis Patients

Background and objectivesStudy of respiratory variations in mitral valve (MV) Doppler flow in hemodialysis (HD) patients has not been investigated and normal adult referenced echocardiographic value is used as an echocardiographic reference to HD patients who have unique hemodynamic. This work aimed to study the respiratory variation in MV Doppler flow in HD patients to determine if it has a unique pattern in these patients, and to study any relation between this variation and volume-related parameters.MethodsWe conducted a prospective cohort study, carried out on 118 patients who underwent regular HD. A standard echocardiography was performed on the patients before and within 6 hs after dialysis. During quiet breathing, the transmitral spectral Doppler E wave was measured during inspiratory and expiratory phases using plethysmography breath-cycle chest-adhesive electrodes. The mathematic differences and the percent changes (ventricular interdependent; VI) in E wave were calculated pre-and post-dialysis. Post dialysis difference in the percent changes (∆ E wave % changes) was calculated as follows: pre-dialysis percent changes of E wave – post dialysis percent changes of E wave/pre dialysis percent changes E wave x 100. ResultsThe means of the mathematic differences between the MV inspiratory and expiratory E pre-and post-dialysis were 0.07 ± 0.18 m/s and 0.08 ± 0.22 m/s respectively with an insignificant difference between both phases; p = 0.337. Meanwhile, the means of the percent variation in the MV inspiratory and expiratory E pre-and post-dialysis were 56 ± 7 % and 44 ± 1.1 % respectively, with a significant reduction after dialysis; P = 0.000. Spearman correlation showed a significant positive correlation between post- dialysis ∆ E wave % change and post-dialysis % change of weight (r = 0.318; P = 0.000). Moreover, post- dialysis % change of weight and post- dialysis % changes of most other volume-related variable were independent predictors of post- dialysis ∆ E wave % in HD patients. ConclusionThe pre- and post- dialysis respiratory changes in the MV E wave in HD patients were higher than the normal adult referenced values. This marked variation could be explained by the unique overloading condition and could explain the LV diastolic dysfunction and the unexplained pulmonary hypertension in HD patients.

Respiration Monitoring via Forcecardiography Sensors

In the last few decades, a number of wearable systems for respiration monitoring that help to significantly reduce patients’ discomfort and improve the reliability of measurements have been presented. A recent research trend in biosignal acquisition is focusing on the development of monolithic sensors for monitoring multiple vital signs, which could improve the simultaneous recording of different physiological data. This study presents a performance analysis of respiration monitoring performed via forcecardiography (FCG) sensors, as compared to ECG-derived respiration (EDR) and electroresistive respiration band (ERB), which was assumed as the reference. FCG is a novel technique that records the cardiac-induced vibrations of the chest wall via specific force sensors, which provide seismocardiogram-like information, along with a novel component that seems to be related to the ventricular volume variations. Simultaneous acquisitions were obtained from seven healthy subjects at rest, during both quiet breathing and forced respiration at higher and lower rates. The raw FCG sensor signals featured a large, low-frequency, respiratory component (R-FCG), in addition to the common FCG signal. Statistical analyses of R-FCG, EDR and ERB signals showed that FCG sensors ensure a more sensitive and precise detection of respiratory acts than EDR (sensitivity: 100% vs. 95.8%, positive predictive value: 98.9% vs. 92.5%), as well as a superior accuracy and precision in interbreath interval measurement (linear regression slopes and intercepts: 0.99, 0.026 s (R2 = 0.98) vs. 0.98, 0.11 s (R2 = 0.88), Bland–Altman limits of agreement: ±0.61 s vs. ±1.5 s). This study represents a first proof of concept for the simultaneous recording of respiration signals and forcecardiograms with a single, local, small, unobtrusive, cheap sensor. This would extend the scope of FCG to monitoring multiple vital signs, as well as to the analysis of cardiorespiratory interactions, also paving the way for the continuous, long-term monitoring of patients with heart and pulmonary diseases.

FLOWSTANDART PHONOPNEUMOGRAPHY QUIET BREATHING IN THE DIAGNOSIS OF COMORBID CURRENT COMMUNITYACQUIRED PNEUMONIA

The aim of our study was to estimate the potential of the flow about standardized panoramogram quiet breathing (PFPG SD) for the diagnosis of inflammation in patients with community-acquired pneumonia on a background of chronic obstructive pulmonary disease (COPD).Materials and methods: 36 healthy male volunteers aged 18 to 76 years old and 36 men with CAP on the background of COPD aged 45 to 80 years old, hospitalized in the Department of the Ministry of Defense of the Far East Branch of the Russian Academy of Sciences, and were examined. PFPG SD was performed on admission to all patients and healthy individuals.Results and discussion: Spectral criteria for acoustic diagnostics of the focus of patients with CAP on the background of COPD were developed, determined by PFPG SD. The maximum specificity for the group of healthy people was reached — 80,5%, the maximum sensitivity of detecting the focus of inflammation — 83,3%. The sensitivity of PFPG SD exceeds the sensitivity of subjective auscultation. The types of acoustic pattern and their threshold values for patients were revealed.

Assessment of dispersion of airborne particles of oral/nasal fluid by high flow nasal cannula therapy

Background Nasal High Flow (NHF) therapy delivers flows of heated humidified gases up to 60 LPM (litres per minute) via a nasal cannula. Particles of oral/nasal fluid released by patients undergoing NHF therapy may pose a cross-infection risk, which is a potential concern for treating COVID-19 patients. Methods Liquid particles within the exhaled breath of healthy participants were measured with two protocols: (1) high speed camera imaging and counting exhaled particles under high magnification (6 participants) and (2) measuring the deposition of a chemical marker (riboflavin-5-monophosphate) at a distance of 100 and 500 mm on filter papers through which air was drawn (10 participants). The filter papers were assayed with HPLC. Breathing conditions tested included quiet (resting) breathing and vigorous breathing (which here means nasal snorting, voluntary coughing and voluntary sneezing). Unsupported (natural) breathing and NHF at 30 and 60 LPM were compared. Results Imaging: During quiet breathing, no particles were recorded with unsupported breathing or 30 LPM NHF (detection limit for single particles 33 μm). Particles were detected from 2 of 6 participants at 60 LPM quiet breathing at approximately 10% of the rate caused by unsupported vigorous breathing. Unsupported vigorous breathing released the greatest numbers of particles. Vigorous breathing with NHF at 60 LPM, released half the number of particles compared to vigorous breathing without NHF. Chemical marker tests: No oral/nasal fluid was detected in quiet breathing without NHF (detection limit 0.28 μL/m3). In quiet breathing with NHF at 60 LPM, small quantities were detected in 4 out of 29 quiet breathing tests, not exceeding 17 μL/m3. Vigorous breathing released 200–1000 times more fluid than the quiet breathing with NHF. The quantities detected in vigorous breathing were similar whether using NHF or not. Conclusion During quiet breathing, 60 LPM NHF therapy may cause oral/nasal fluid to be released as particles, at levels of tens of μL per cubic metre of air. Vigorous breathing (snort, cough or sneeze) releases 200 to 1000 times more oral/nasal fluid than quiet breathing (p < 0.001 with both imaging and chemical marker methods). During vigorous breathing, 60 LPM NHF therapy caused no statistically significant difference in the quantity of oral/nasal fluid released compared to unsupported breathing. NHF use does not increase the risk of dispersing infectious aerosols above the risk of unsupported vigorous breathing. Standard infection prevention and control measures should apply when dealing with a patient who has an acute respiratory infection, independent of which, if any, respiratory support is being used. Clinical trial registration ACTRN12614000924651