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.

Poor Correlation between Diaphragm Thickening Fraction and Transdiaphragmatic Pressure in Mechanically Ventilated Patients and Healthy Subjects

Background The relationship between the diaphragm thickening fraction and the transdiaphragmatic pressure, the reference method to evaluate the diaphragm function, has not been clearly established. This study investigated the global and intraindividual relationship between the thickening fraction of the diaphragm and the transdiaphragmatic pressure. The authors hypothesized that the diaphragm thickening fraction would be positively and significantly correlated to the transdiaphragmatic pressure, in both healthy participants and ventilated patients. Methods Fourteen healthy individuals and 25 mechanically ventilated patients (enrolled in two previous physiologic investigations) participated in the current study. The zone of apposition of the right hemidiaphragm was imaged simultaneously to transdiaphragmatic pressure recording within different breathing conditions, i.e., external inspiratory threshold loading in healthy individuals and various pressure support settings in patients. A blinded offline breath-by-breath analysis synchronously computed the changes in transdiaphragmatic pressure, the diaphragm pressure-time product, and diaphragm thickening fraction. Global and intraindividual relationships between variables were assessed. Results In healthy subjects, both changes in transdiaphragmatic pressure and diaphragm pressure-time product were moderately correlated to diaphragm thickening fraction (repeated measures correlation = 0.40, P < 0.0001; and repeated measures correlation = 0.38, P < 0.0001, respectively). In mechanically ventilated patients, changes in transdiaphragmatic pressure and thickening fraction were weakly correlated (repeated measures correlation = 0.11, P = 0.008), while diaphragm pressure-time product and thickening fraction were not (repeated measures correlation = 0.04, P = 0.396). Individually, changes in transdiaphragmatic pressure and thickening fraction were significantly correlated in 8 of 14 healthy subjects (ρ = 0.30 to 0.85, all P < 0.05) and in 2 of 25 mechanically ventilated patients (ρ = 0.47 to 0.64, all P < 0.05). Diaphragm pressure-time product and thickening fraction correlated in 8 of 14 healthy subjects (ρ = 0.41 to 0.82, all P < 0.02) and in 2 of 25 mechanically ventilated patients (ρ = 0.63 to 0.66, all P < 0.01). Conclusions Overall, diaphragm function as assessed with transdiaphragmatic pressure was weakly related to diaphragm thickening fraction. The diaphragm thickening fraction should not be used in healthy subjects or ventilated patients when changes in diaphragm function are evaluated. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

Is sarcopenia a risk factor for reduced diaphragm function following hepatic resection? A study protocol for a prospective observational study

IntroductionSarcopenia is associated with reduced pulmonary function in healthy adults, as well as with increased risk of pneumonia following abdominal surgery. Consequentially, postoperative pneumonia prolongs hospital admission, and increases in-hospital mortality following a range of surgical interventions. Little is known about the function of the diaphragm in the context of sarcopenia and wasting disorders or how its function is influenced by abdominal surgery. Liver surgery induces reactive pleural effusion in most patients, compromising postoperative pulmonary function. We hypothesise that both major hepatic resection and sarcopenia have a measurable impact on diaphragm function. Furthermore, we hypothesise that sarcopenia is associated with reduced preoperative diaphragm function, and that patients with reduced preoperative diaphragm function show a greater decline and reduced recovery of diaphragm function following major hepatic resection. The primary goal of this study is to evaluate whether sarcopenic patients have a reduced diaphragm function prior to major liver resection compared with non-sarcopenic patients, and to evaluate whether sarcopenic patients show a greater reduction in respiratory muscle function following major liver resection when compared with non-sarcopenic patients.Methods and analysisTranscostal B-mode, M-mode ultrasound and speckle tracking imaging will be used to assess diaphragm function perioperatively in 33 sarcopenic and 33 non-sarcopenic patients undergoing right-sided hemihepatectomy starting 1 day prior to surgery and up to 30 days after surgery. In addition, rectus abdominis and quadriceps femoris muscles thickness will be measured using ultrasound to measure sarcopenia, and pulmonary function will be measured using a hand-held bedside spirometer. Muscle mass will be determined preoperatively using CT-muscle volumetry of abdominal muscle and adipose tissue at the third lumbar vertebra level (L3). Muscle function will be assessed using handgrip strength and physical condition will be measured with a short physical performance battery . A rectus abdominis muscle biopsy will be taken intraoperatively to measure proteolytic and mitochondrial activity as well as inflammation and redox status. Systemic inflammation and sarcopenia biomarkers will be assessed in serum acquired perioperatively.Ethics and disseminationThis trial is open for recruitment. The protocol was approved by the official Independent Medical Ethical Committee at Uniklinik (Rheinish Westphälische Technische Hochschule (RWTH) Aachen (reference EK309-18) in July 2019. Results will be published via international peer-reviewed journals and the findings of the study will be communicated using a comprehensive dissemination strategy aimed at healthcare professionals and patients.Trial registration numberClinicalTrials. gov (EK309-18); Pre-results.

Influence of Dexmedetomidine on Diaphragm Function and Postoperative Outcomes in ICU Patients with Mechanical Ventilation

Objective. To probe into the influence of dexmedetomidine (DEX) on diaphragm function and postoperative outcomes of mechanically ventilated patients in the intensive care unit (ICU). Methods. 84 patients with mechanical ventilation (MV) in the ICU of our hospital were selected as the research participants, including 38 patients in the control group (CG) sedated with midazolam (MZ) and 46 patients in the research group (RG) with DEX sedation. Ramsay sedation score, visual analogue scale (VAS), and restlessness score (RS) were used to evaluate their state before sedation (T0), as well as 2 h (T1), 6 h (T2), and 24 h (T3) after sedation, and the alterations of mean arterial pressure (MAP) and heart rate (HR) were recorded. Serum cortisol (Cor), adrenocorticotropic hormone (ACTH), superoxide dismutase (SOD), malondialdehyde (MDA), interleukin- (IL-) 1β, IL-6, and tumor necrosis factor-α (TNF-α) were measured before and 24 h after sedation. The end-inspiratory diaphragm thickness (DTei) and end-expiratory diaphragm thickness (DTee) were measured within 2 h after the initiation of MV and 5 min after the spontaneous breathing test (SBT), and the diaphragm thickening fraction (DTF) was calculated. Finally, the ventilator weaning, MV time, and the incidence of adverse reactions (ADs) of the two groups were counted. Results. T0 and T3 witnessed no distinct difference in Ramsay, VAS, and RS scores between the two arms ( P > 0.05 ), but at T1 and T2, RG had better sedation state and lower VAS and RS scores than CG ( P < 0.05 ), with more stable vital signs ( P < 0.05 ). After sedation, the contents of oxidative stress and inflammatory factors in RG were lower, while DTee, DTei, and DTF were higher, versus CG ( P < 0.05 ). Moreover, RG presented higher success rate of first ventilator weaning, less MV time, and lower incidence of ADs than CG ( P < 0.05 ). Conclusions. DEX is effective in mechanically ventilated patients in the ICU, which can protect patients against diaphragm function damage, improve the success rate of ventilator weaning, and benefit the postoperative outcome, with excellent and rapid sedation effect and less stress damage to patients.

Application of Ultrasound Evaluation of Diaphragm Function in Guiding Ventilator Evacuation

Objective. To investigate the clinical effect of the application of ultrasound evaluation of diaphragm function in guiding ventilator evacuation. Methods. 100 patients with ventilator evacuation who were admitted to our hospital from March 2019 to June 2020 were selected as the study objects, and divided into the observation group and the control group, according to whether they succeeded in weaning. Among them, 50 patients succeeding in weaning were from the observation group; while 50 patients failing in weaning were from the control group. The Diaphragm Movement Degree (DMD) and Diaphragmatic Thickness at the End of Expiration (DTee), Diaphragmatic Thickness at the End of Inspiration (DTei) and Diaphragm Thickening Fraction (DTF), the right diaphragm displacement, diaphragm contraction velocity at 0 min, 5 min and 30 min of two groups as well as the ROC curve were all analyzed to predict weaning results of the ultrasound diaphragm index. Results. (1) There were no significant differences in Sequential Organ Failure Assessment (SOFA) score. Acute Physiology and Chronic Health Evaluation II (APACHE II) score, ventilator ventilation time and oxygenation index before weaning between the two groups (T=0.14,0.03, 0.04, 0.59, P=0.89, 0.97, 0.56). (2) Left DMD (18.59±2.96) mm. Right DMD (19.86±2.94) mm. Left DTei (2.69±0.16) mm. Right DTei (2.81 ±0.31) mm. Left DTee (1.93±0.11) mm. Right DTee (1.92±0.16) mm. Left DTF (0.40±0.11) mm and Right DTF (0.47±0.09) mm in the observation group were significantly higher than Left DMD (13.05±3.16) mm. Right DMD (13.13±3.63) mm. Left DTei (2.16±0.34) mm. Right DTei (2.18±0.39) mm. Left DTee (1.92±0.16) mm. Right DTee (1.68±0.24) mm. Left DTF (0.25±0.06) mm and right DTF (0.27±0.07) mm in the control group, T = 9.05, 10.19, 9.97, 8.94, 6.93, 5.88, 8.46, 12.40, P=0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, with statistical significance. (3) The ROC curve showed that left and right DMD, left and right DTei, left and right DTee as well as left and right DTF can be used to predict the success of weaning. Conclusion. In the guidance of ventilator evacuation, the application of ultrasound evaluation of diaphragm function can effectively evaluate the timing of weaning, and played a positive role in improving the success rate of weaning.

Application of bedside ultrasound in predicting the outcome of weaning from mechanical ventilation in elderly patients

Background With the increased ageing of society, more and more elderly people are admitted to the intensive care unit, How to accurately predict whether elderly patients can successfully wean from the ventilator is more complicated. Diaphragmatic excursion (DE) and diaphragm thickening fraction (DTF) were measured by bedside ultrasound to assess diaphragm function. The lung ultrasound score (LUS) and the rapid shallow breathing index (RBSI) were used as indices of diaphragm function to predict the outcome of weaning from mechanical ventilation. The aim of this study was to examine the clinical utility of these parameters in predicting extubation success. Methods This prospective study included 101 consecutive elderly patients undergoing a trial of extubation in the ICU of Haidian Hospital between June 2017 and July 2020. Patients were divided into the successful weaning group (n = 69) and the failed weaning group (n = 32). Baseline characteristics, including RSBI, were recorded. Measurements of DE, DTF and LUS were made using ultrasound within 24 h before extubation. Results Median DE was greater in patients with extubation success than in those with extubation failure (1.64 cm vs. 0.78 cm, p = 0.001). Patients with extubation success had a greater DTF than those with extubation failure (49.48% vs. 27.85%, p = 0.001). The areas under the receiver operating curves for the RSBI, LUS, DE and DFT were 0.680, 0.764, 0.831 and 0.881, respectively. The best cut-off values for predicting successful weaning were DTF ≥ 30%, DE ≥ 1.3 cm, LUS ≤ 11, and RSBI ≤ 102. The specificity of DTF (84%) in predicting weaning outcome was higher than that of RBSI (53%), that of LUS (55%), and that of DE (62%). The sensitivity of DTF (94%) was greater than that of RBSI (85%), that of LUS (71%), and that of DE (65%). The combination of RSBI, LUS, DE, and DTF showed the highest AUC (AUC = 0.919), with a sensitivity of 96% and a specificity of 89%. Conclusions DTF has higher sensitivity and specificity for the prediction of successful weaning in elderly patients than the other parameters examined. The combination of RSBI, LUS, DE and DFT performed well in predicting weaning outcome. This has potentially important clinical application and merits further evaluation.

Mitoquinone Mesylate (MitoQ) Prevents Sepsis Induced Diaphragm Dysfunction

Sepsis-induced diaphragm dysfunction is a major contributor to respiratory failure in mechanically ventilated patients. There are no pharmacological treatments for this syndrome, but studies suggest that diaphragm weakness is linked to mitochondrial free radical generation. We hypothesized that administration of mitoquinone mesylate (MitoQ), a mitochondrially targeted free radical scavenger, would prevent sepsis- induced diaphragm dysfunction. We compared diaphragm function in 4 groups of male mice: (a) sham operated controls treated with saline (0.3 ml intraperitoneally, IP), (b) sham operated mice treated with MitoQ (3.5 mg/kg/day given IP in saline), (c) cecal ligation puncture (CLP) mice treated with saline, and (d) CLP mice treated with MitoQ. Forty-eight hours after surgery, we assessed diaphragm force generation, myosin heavy chain content, mitochondrial oxygen consumption (OCR) and aconitase activity. We also determined the effect of MitoQ administration in female mice with CLP sepsis and in mice with endotoxin-induced sepsis. CLP decreased diaphragm specific force generation and MitoQ prevented these decrements (e.g. maximal force averaged 30.2 ± 1.3, 28.0 ± 1.3, 12.8 ± 1.9 and 30.0 ± 1.0 N/cm2 for sham, sham + MitoQ, CLP, and CLP + MitoQ groups, p<0.001). CLP also reduced diaphragm mitochondrial OCR and MitoQ blocked this effect. Similar responses were observed in female mice, and in endotoxin-induced sepsis. Moreover, delayed MitoQ treatment was as effective as immediate treatment. These data indicate that MitoQ prevents sepsis-induced diaphragm dysfunction, preserving force generation and reducing fatigue. MitoQ may be a useful therapeutic agent to preserve diaphragm function in septic, critically ill patients.