Ultrasound evaluation of diaphragmatic mobility in patients with idiopathic lung fibrosis: a pilot study

[Diaphragmatic ultrasonography for the pulmonologist: Technique and clinical use]

INTRODUCTION

Ultrasonography is an emerging tool that helps to assess diaphragmatic function. It is now widely used in ICUs to predict weaning from mechanical ventilation. Ultrasonography is readily available, harmless (no radiation), and repeatable with good interoperator reproducibility. Over the past few years, ultrasonography has seen increasing use in patients with chronic pulmonary pathologies.

STATE OF THE ART

The aim of this review is (1) to describe the ultrasound techniques used to assess diaphragmatic excursion and thickening, (2) to indicate the expected, normal values in healthy patients, and (3) to summarize the main findings and clinical applications in treatment of chronic respiratory disorders.

CONCLUSIONS

Chronic pulmonary diseases are associated with diaphragmatic dysfunction that can be assessed with ultrasound. Diaphragmatic dysfunction is primary in neuromuscular disorders and secondary to respiratory disease in other chronic pulmonary conditions (COPD, ILD). Ultrasound is correlated with the severity of the underlying disease (functional and clinical parameters).

PERSPECTIVES

The prognostic interest of diaphragm ultrasonography remains to be established, after which its utilization should become routine.

Amelioration of acetic acid-induced ulcerative colitis in rats by cetirizine and loratadine via regulation of the PI3K/Akt/Nrf2 signalling pathway and pro-inflammatory cytokine release

Objectives

Ulcerative colitis is a chronic inflammatory bowel disease (IBD) that causes inflammation and ulcers in the rectum and the innermost layer of the large intestine. Our study aimed to elucidate the ameliorative effect of cetirizine (CTZ) and loratadine (LOR) against acetic acid-induced ulcerative colitis in rats via assessment of the PI3K/p-Akt/Nrf2 signaling pathway and proinflammatory cytokine release.

Materials and Methods

Thirty-two rats were allocated into four groups (n=8). Group (I) was considered normal control. Acetic acid (AA) was injected intrarectally in groups (2-4). Group (2) was kept untreated. Group (3) was administered CTZ (20 mg/kg/day) for 7 days. Group (4) was administered LOR (10 mg/kg/day) for 7 days.

Results

AA showed severe macroscopic colonic lesions associated with increased ulcer number, area, and severity with significantly elevated PI3K, p-Akt, Nrf2, TNF-α, and IL-6 in colorectal tissue as compared to the normal control group. All the aforementioned indicators were greatly improved by CTZ and LOR therapy.

Conclusion

This is the first study to elucidate the ameliorative effect of CTZ and LOR against AA-induced UC in rats. CTZ and LOR treatment mitigates UC via amelioration of the PI3K/p-Akt/Nrf2 pathway and proinflammatory cytokine release.

The effect of abdominal bracing on respiration during a lifting task: a cross-sectional study

BACKGROUND

Abdominal bracing is a maneuver widely used by rehabilitation specialists and sports trainers to improve spinal stability. This study aimed to investigate how lifting tasks with and without abdominal bracing affect the respiratory function of the diaphragm.

METHODS

M-mode ultrasonographic assessment of diaphragmatic motion combined with spirometry was performed on 31 healthy adults. Participants were asked to breathe continuously whilst lifting a load with spontaneous abdominal muscle contraction (natural loaded breathing) and abdominal bracing (AB loaded breathing).

RESULTS

Pearson's correlations revealed strong correlations between ultrasonography and spirometry measures (p < 0.001) for all types of breathing: tidal breathing (r = 0.709, r2 = 0.503), natural loaded breathing (r = 0.731, r2 = 0.534) and AB loaded breathing (r = 0.795, r2 = 0.632). Using paired-samples t-tests, the natural loaded breathing ultrasonography revealed more caudal diaphragm positions during inspiration (p < 0.001) but not during expiration (p = .101). Spirometry demonstrated lower lung volumes (L) at the end of inspiration and expiration (p < 0.001), with no changes in total lung volume (p = 0.06). The AB loaded breathing ultrasonography revealed more caudal diaphragm positions during inspiration (p = 0.002) but not during expiration (p = 0.05). Spirometry demonstrated lower lung volumes at the end of inspiration (p < 0.001), expiration (p = 0.002), and total lung volumes (p = 0.019).

CONCLUSION

This study demonstrated that abdominal bracing performed during a lifting task reduces lung volume despite an increase in diaphragmatic motion. Diaphragm excursions strongly correlate with lung volumes even under postural loading.

TRIAL REGISTRATION

The study was prospectively registered on 8 April 2021 at ClinicalTrials.gov with identification number NCT04841109.

Prevalence of diaphragm dysfunction in patients with interstitial lung disease (ILD): The role of diaphragmatic ultrasound

BACKGROUND

Diaphragm ultrasound (DUS) has been extensively used in critically ill patients while data on outpatients with interstitial lung disease (ILD) are limited. We hypothesized that diaphragm function, assessed by ultrasound, could be impaired in patients with ILD, considering both Idiopathic Pulmonary Fibrosis (IPF) and Connective Tissue Disease (CTD-ILD), compared to healthy subjects. Moreover, this impairment could impact clinical and functional parameters.

METHODS

All consecutive CTD-ILD and IPF patients followed in our center (March-October 2020) were screened. Diaphragm displacement (DD), inspiratory thickness (Ti), expiratory thickness (Te), thickening fraction (TF), and respiratory functional parameters were collected. The prevalence of diaphragmatic dysfunction (TF <30%) was then recorded.

RESULTS

Eighty-two consecutive patients (41 CTD-ILD, 41 IPF) and 15 age- and sex-matched controls were enrolled. In the overall population, 24 out of 82 (29%) presented diaphragmatic dysfunction. In CTD-ILD, DD and Ti were lower as compared to IPF (p = 0.021 and p = 0.036, respectively); while diaphragmatic dysfunction was more prevalent compared to controls (37% vs 7%, p = 0.043). TF positively correlated to patients' functional parameters in the CTD-ILD group (FVC%pred: p = 0.003; r = 0.45), while not in the IPF group. Diaphragmatic dysfunction was associated with moderate/severe dyspnea in both CTD-ILD and IPF (p = 0.021).

CONCLUSION

The prevalence of diaphragmatic dysfunction was 29% in patients with ILD and was associated with moderate/severe dyspnea. CTD-ILD presented lower DD compared with IPF and a higher prevalence of diaphragmatic dysfunction (TF<30%) compared with controls. TF was associated with lung function only in CTD-ILD patients, suggesting its potential role in the comprehensive patient assessment.

Multiform-based Baduanjin exercise prevention and treatment for idiopathic pulmonary fibrosis: study protocol for a randomized controlled trial

INTRODUCTION

In this study, we will combine the traditional Baduanjin with Yijin Jing and Wuqinxi to create an optimized Baduanjin exercise program with three different forms (vertical, sitting, and horizontal) to adapt to idiopathic pulmonary fibrosis (IPF) patients in vairous stages of the disease. The purpose of this study is to explore and compare the therapeutic effects of this multi-form Baduanjin, traditional Baduanjin, and resistance training on lung function and limb motor function in IPF patients. The goal of this study is to prove a novel optimal exercise prescription strategy of Baduanjin exercise for improving and protecting lung function in IPF patients.

METHODS/DESIGN

A single-blind and randomized controlled trial is used to conduct this study, while the randomization list will be generated using a computerized random number generator and opaque sealed envelopes with group allocation will be prepared. It will be strictly followed to blind the outcome assessors. and until the experiment's conclusion, participants won't know which group they are enrolled in. Patients between the ages of 35 and 80 who have stable diseases and have not regularly practiced Baduanjin exercise in the past will be included. They are divvied up into the following five groups at random: (1) The conventional care group (control group, CG), (2) The traditional Baduanjin exercise group (TG), (3) The modified Baduanjin exercise group (IG), (4) The resistance exercise group (RG) (5) The modified Baduanjin exercise combined with resistance exercise group (IRG). Those CG participants only received the usual treatment, while TC, IG, and RG participants exercised 1 h twice a day for 3 months. MRG participants will have a 3-month intervention with 1 h of Modified Baduanjin Exercise and 1 H of Resistance Training for each day. Every week, all groups underwent will supervis one-day training, with the exception of the control group. The Pulmonary Function Testing (PFT), HRCT, and 6MWT are the main outcome variables. The St. George Respiratory Questionnaire and mMRC are used as secondary outcome measures.

DISCUSSION

This study may produce a new Baduanjin exercise prescription that is user-friendly, simple to execute, more targeted, and adaptable. Because it consists of three forms, including vertical, sitting, and horizontal, it is more adaptable to the various disease stages and actual situations of IPF patients and may compensate for the shortcomings of conventional pulmonary rehabilitation and traditional Baduanjin.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2200055559 . Registered on 12 January 2022.

Diaphragmatic ultrasonography in patients with IPF: Is diaphragmatic structure and mobility related to fibrosis severity and pulmonary functional changes?

Introduction

There is evidence to suggest that dyspnea and impaired exercise capacity are associated with respiratory muscle dysfunction in idiopathic pulmonary fibrosis (IPF) patients. We aimed to evaluate the functions of the diaphragm with ultrasonography (US) and to determine the correlation of the data obtained with the pulmonary function parameters of the patients, exercise capacity, and the extent of fibrosis radiologically.

Materials and Methods

Diaphragmatic mobility, thickness, and thickening fraction (TF) were measured by ultrasonography in IPF patients and the control group. The correlation between these measurements, pulmonary function tests (PFT), six-minute walking test (6MWT), mMRC score, and total fibrosis score (TFS) was evaluated.

Result

Forty-one IPF patients and twenty-one healthy volunteers were included in the study. No difference was found between the patient and control groups in diaphragmatic mobility during quiet breathing (QB) on ultrasound (2.35 cm and 2.56 cm; p= 0.29). Diaphragmatic mobility during deep breathing (DB) was found to be lower in the patient group when compared to the control group (5.02 cm and 7.66 cm; p<0.0001). Diaphragmatic thickness was found to be higher during QB and DB in IPF patients (0.33 cm and 0.31 cm, p= 0.043; 0.24 cm and 0.22 cm, p= 0.045). No difference was found between the two groups in terms of thickening fraction (39.37%, 44.16%; p= 0.49). No significant correlation was found between US measurements and PFT, 6MWT, mMRC score, and TFS in IPF patients (p> 0.05).

Conclusions

The functions of the diaphragm do not appear to be affected in patients with mild-to-moderate restrictive IPF. This study showed that there was no relationship between diaphragmatic functions and respiratory function parameters and the extent of fibrosis. Further studies, including advanced stages of the disease, are needed to understand the changes in diaphragmatic functions in IPF and to determine whether this change is associated with respiratory function parameters and the extent of fibrosis.

Differences in lung and lobe volumes between supine and upright computed tomography in patients with idiopathic lung fibrosis

No clinical study has compared lung or lobe volumes on computed tomography (CT) between the supine and standing positions in patients with idiopathic lung fibrosis (IPF). This study aimed to compare lung and lobe volumes between the supine and standing positions and evaluate the correlations between the supine/standing lung volumes on CT and pulmonary function in patients with IPF. Twenty-three patients with IPF underwent a pulmonary function test and both low-dose conventional (supine position) and upright CT (standing position) during inspiration breath-holds. The volumes of the total lungs and lobes were larger in the standing than in the supine position in patients with IPF (all p < 0.05). Spearman's correlation coefficients between total lung volumes on chest CT in supine/standing positions and vital capacity (VC) or forced VC (FVC) were 0.61/0.79 or 0.64/0.80, respectively. CT-based volumes on upright CT were better correlated with VC and FVC than those on supine CT. Lung and lobe volumes in the standing position may be useful biomarkers to assess disease severity or therapeutic effect in patients with IPF.

Diaphragmatic plication among lung transplant patients: A single-center experience

BACKGROUND

There is lack of data reporting outcomes among patients needing diaphragmatic plication (DP) during or after lung transplantation (LT). We sought to assess the association of DP with post-transplant spirometry among other outcomes.

METHODS

We included all patients who underwent LT between 2012&2016 (n = 324, mean age 56.3±13.4 years; M:F 198:126). We compared early and late outcomes based on the need for DP.

RESULTS

The frequency of diaphragm dysfunction (DD)on pre-transplant fluoroscopy was 52.2%. A total of 38 DP procedures were performed among 37 patients (11.4% of LT patients). DP was done for anatomic (sizing or spacing issues) or functional indications (symptomatic DD). While patients with DP had significantly lower spirometry throughout the 3-year follow-up period, their slope of decline, functional assessments at the first annual visit, the risk of CLAD, and mortality were similar to patients without DP. A sub-group analysis limited to patients with restrictive lung diseases as the transplant indication had similar findings.

CONCLUSIONS

Pre-transplant DD is common among LT candidates although it did not predict the need for DP. DP may be performed for functional or anatomic indications especially for addressing the donor-recipient size mismatch. Despite the lack of favorable effect on post-transplant spirometry, patients undergoing DP have acceptable and comparable early and late outcomes. This article is protected by copyright. All rights reserved.

Diaphragm Ultrasound in the Evaluation of Diaphragmatic Dysfunction in Lung Disease

The diaphragm is the most important respiratory muscle, and its function may be limited by acute and chronic diseases. A diaphragmatic ultrasound, which quantifies dysfunction through different approaches, is useful in evaluating work of breathing and diaphragm atrophy, predicting successful weaning, and diagnosing critically ill patients. This technique has been used to determine reduced diaphragmatic function in patients with chronic obstructive pulmonary disease and interstitial diseases, while in those with COVID-19, diaphragmatic ultrasound has been used to predict weaning failure from mechanical ventilation.

Diagnostic imaging in COVID-19 pneumonia: a literature review

In December 2019 in Wuhan (China), a bat-origin coronavirus (2019-nCoV), also known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was identified, and the World Health Organization named the related disease COVID-19. Its most severe manifestations are pneumonia, systemic and pulmonary thromboembolism, acute respiratory distress syndrome (ARDS), and respiratory failure. A swab test is considered the gold standard for the diagnosis of COVID-19 despite the high number of false negatives. Radiologists play a crucial role in the rapid identification and early diagnosis of pulmonary involvement. Lung ultrasound (LUS) and computed tomography (CT) have a high sensitivity in detecting pulmonary interstitial involvement. LUS is a low-cost and radiation-free method, which allows a bedside approach and needs disinfection of only a small contact area, so it could be particularly useful during triage and in intensive care units (ICUs). High-resolution computed tomography (HRCT) is particularly useful in evaluating disease progression or resolution, being able to identify even the smallest changes.

One year of SARS-CoV-2 and lung ultrasound: what has been learned and future perspectives

A first screening by ultrasound can be relevant to set a specific diagnostic and therapeutic route for a patient with a COVID-19 infection. The finding of bilateral B-lines and white lung areas with patchy peripheral distribution and sparing areas is the most suggestive ultrasound picture of COVID-19 pneumonia. Failure to detect bilateral interstitial syndrome (A pattern) on ultrasound excludes COVID-19 pneumonia with good diagnostic accuracy, but does not exclude current infection. The use of shared semiotic and reporting schemes allows the comparison and monitoring of the COVID-19 pulmonary involvement over time. This review aims to summarise the main data on pulmonary ultrasound and COVID-19 to provide accurate and relevant information for clinical practice.

Diaphragmatic thickness and excursion by lung ultrasound in pediatric chronic pulmonary diseases

PURPOSE

Many patients with chronic pulmonary diseases, such as interstitial lung disease, cystic fibrosis, and non-cystic fibrosis bronchiectasis, suffer from dyspnea and exercise intolerance. Reduced lung compliance is the main cause of the patients' dyspnea, but weak respiratory muscles could be an additional factor. The diaphragm is considered the major respiratory muscle. Our study aimed to detect diaphragmatic thickness and excursion by ultrasound in pediatric patients with chronic pulmonary diseases to assess respiratory muscle weakness in these patients.

METHODS

A case-control study was conducted on 130 patients with pediatric chronic pulmonary diseases (childhood interstitial lung diseases, cystic fibrosis, and non-cystic fibrosis bronchiectasis) and 100 control subjects. Ultrasound was used to detect diaphragmatic excursion and thickness, which were correlated with the severity of the disease, both clinically and functionally.

RESULTS

The right and left diaphragmatic excursions were significantly lower in the patients (19.469 ± 9.984 and 18.5 ± 10.131, respectively) than in the control subjects (29.6 ± 14.131 and 25.6 ± 12.827, respectively) (p values of 0.002 and 0.019). In contrast, the difference in the right and left diaphragmatic thicknesses between the patients and the controls was statistically insignificant (p values of 0.884 and 0.344). The left diaphragmatic excursion was positively correlated with the patients' age and weight, while both the right and the left diaphragmatic excursion significantly correlated with the patients' height, FEV1/FVC ratio, and heart rate.

CONCLUSION

The diaphragmatic excursion is lower in children and adolescents with chronic pulmonary diseases than in healthy control subjects. The diaphragmatic excursion is positively correlated with patients' age, weight, height, FEV1/FVC ratio, and heart rate.

Role of shear-wave and strain elastography to differentiate malignant vs benign subpleural lung lesions

Elastosonography is a non-invasive diagnostic method to evaluate tissue stiffness. The aim of our study was to demonstrate the applicability and efficacy of elastosonography to differentiate benign vs malignant subpleural lung lesions compared to clinical, radiological and histological findings.We performed both strain and shear wave velocity (SWV) elastosonography on subpleural lung lesions. Moreover, we elaborated a composite score called "elasto index".Fourteen patients, 10 males and 4 females were recruited. On strain elastography, 9 lesions showed a hard pattern (type 3), 3 lesions showed an intermediate pattern (type 2), and 2 lesions a soft pattern (type 1). All lesions showed a mean SWV value of 4.46 ± 2.37 m/second. The mean SWV for malignant lesions (n = 6) was 5.92 ± 2.8 m/second. The mean SWV for benign lesions (n = 8) was 3.36 ± 1.20 m/second. SWV shows an area under the curve (AUC) of 0.792, and the Youden index shows a value of 3.6 m/second. The ROC curve elaborated for the diagnosis of malignancy by strain elastography showed an AUC of 0.688. ROC curve for the diagnosis of malignancy by elasto index demonstrated an AUC of 0.802.SWV values obtained by ARFI elastosonographic method are higher in malignant lung lesions (mean SWV: 5.92 m/second) than in benign ones (mean SWV: 3.36); a composite score (elasto index) is characterized by better statistical significance for the differentiation of the lesions.

Diaphragmatic ultrasound: a review of its methodological aspects and clinical uses

The diaphragm is the main muscle of respiration, acting continuously and uninterruptedly to sustain the task of breathing. Diaphragmatic dysfunction can occur secondary to numerous pathological conditions and is usually underdiagnosed in clinical practice because of its nonspecific presentation. Although several techniques have been used in evaluating diaphragmatic function, the diagnosis of diaphragmatic dysfunction is still problematic. Diaphragmatic ultrasound has gained importance because of its many advantages, including the fact that it is noninvasive, does not expose patients to radiation, is widely available, provides immediate results, is highly accurate, and is repeatable at the bedside. Various authors have described ultrasound techniques to assess diaphragmatic excursion and diaphragm thickening in the zone of apposition. Recent studies have proposed standardization of the methods. This article reviews the usefulness of ultrasound for the evaluation of diaphragmatic function, addressing the details of the technique, the main findings, and the clinical applications.

Pelvic Floor Considerations in COVID-19

BACKGROUND

Much of the research and clinical commentary on COVID-19 have been focused on respiratory function. Pelvic floor therapists understand that both respiratory dysfunction and hospitalization can have an impact on pelvic floor function. This clinical commentary provides context as to how the long-term effects of COVID-19 could affect the pelvic floor as well as some generalized treatment considerations.

DISCUSSION

The respiratory diaphragm has an impact on the ability of the pelvic floor to contract and relax in a manner that will allow for both continence and elimination. COVID-19 survivors often have disability in this muscle of respiration that can lead to implications for both overactive and underactive pelvic floor. Commonly, this population is hospitalized for long periods of time, which can have long-term consequences on both bladder and bowel functioning including, but not limited to, incontinence, urinary retention, and constipation. Pelvic floor therapists must be prepared to adjust both their evaluation and treatment methods in consideration of this novel treatment population.

CONCLUSIONS

Because of the pervasive nature of this virus, pelvic floor physical therapists should be a part of the rehabilitation team treating these patients once they have become medically stable.Video abstract with sound available at http://links.lww.com/JWHPT/A36.

A Model for SARS-CoV-2 Infection with Treatment

The current emergence of coronavirus (SARS-CoV-2) puts the world in threat. The structural research on the receptor recognition by SARS-CoV-2 has identified the key interactions between SARS-CoV-2 spike protein and its host (epithelial cell) receptor, also known as angiotensin-converting enzyme 2 (ACE2). It controls both the cross-species and human-to-human transmissions of SARS-CoV-2. In view of this, we propose and analyze a mathematical model for investigating the effect of CTL responses over the viral mutation to control the viral infection when a postinfection immunostimulant drug (pidotimod) is administered at regular intervals. Dynamics of the system with and without impulses have been analyzed using the basic reproduction number. This study shows that the proper dosing interval and drug dose both are important to eradicate the viral infection.

Thoracic ultrasound and SARS-COVID-19: a pictorial essay

Thoracic ultrasound seems to adapt to the screening for lung involvement of patients with suspected or ascertained SARS-COVID-19 infection due to its characteristics of easy applicability. It can be also a relevant method in monitoring patients. B lines are early finding of COVID-19, even in mild-symptomatic subjects; in the most serious cases such as pre-ARDS or ARDS, the B lines end up filling the ultrasound image almost completely, until it merges, so as to create a single hyperechoic image named as "white lung", with distortion and irregularity of the pleural line. In advanced stage, lung consolidations are present, representing pulmonary pathological areas that are no longer normally ventilated.

From an abdominal ultrasound to a lung disease passing through the diaphragm: a case of idiopathic pulmonary fibrosis

RATIONALE

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease characterized by abnormal and excessive deposition of collagen in the pulmonary interstitium (fibrosis) with minimal associated inflammation evolving into progressive and irreversible decline in lung function.

PATIENT CONCERNS

Patient referred discomfort, bilateral upper quadrant abdominal pain, and progressive exertional dyspnea (shortness of breath with exercise).

DIAGNOSIS

Exertional dyspnea due to idiopathic pulmonary fibrosis (IPF).

INTERVENTION

Sonographic evaluation demonstrated an alteration of diaphragm excursion together with a relevant alteration of the pleural line and multiple irregular and confluent B lines.

CONCLUSIONS

Lung and diaphragm ultrasound could be employed as a screening or first-line diagnostic tool in the suspicion of interstitial lung disease.

Not all abolished lung sliding are pneumothorax: the case of a particular lung atelectasis

INTRODUCTION

Lung ultrasound (LUS) is expanding from the field of emergency medicine, also to the pneumological specialist field, becoming part of the diagnostic procedure of lung consolidation.

CASE PRESENTATION

A 78-year-old male was admitted to our emergency department for exertional dyspnea. LUS was performed, thus showing at right hemitorax air interface, A lines pattern, pleural sliding abolished on the whole hemitorax, thus suggesting a pneumothorax, but no evidence of lung point. A scan of lower lung segment showed an absence of the diaphragmatic excursion, suggestive for hemiparalysis of the diaphragm muscle, then confirmed by a subcostal scan. Moreover, at the lower segment of right hemitorax there was mild pleural effusion allowing the visualization of a round-shaped parenchymal consolidation with the absence of air bronchograms.

CONCLUSIONS

LUS allowed the visualization of a particular and rare disease such as anthracosis-associated rounded atelectasis, thus leading to a more correct and faster patient management.

Mobility impact and methods of diaphragm monitoring in patients with chronic obstructive pulmonary disease: a systematic review

The objectives of the study were to identify the factors that limit diaphragmatic mobility and evaluate the therapeutic results of the monitoring methods previously used in patients with chronic obstructive pulmonary disease. The PubMed, Web of Science, Scopus, and LILACS databases were used. A gray literature search was conducted with Google scholar. PRISMA was used, and the bias risk analysis adapted from the Cochrane Handbook for clinical trials and, for other studies, the Downs and Black checklist were used. Twenty-five articles were included in the qualitative synthesis analysis on physiotherapeutic techniques and diaphragmatic mobility. Eight clinical trials indicated satisfactory domains, and on the Downs and Black scale, 17 cohort studies were evaluated to have an acceptable score. Different conditions must be observed; for example, for postoperative assessments the supine position is suggested to be the most appropriate position to verify diaphragm excursion, although it has been shown to be associated with difficulty of restriction and matching in samples. Therefore, we identified the need for contemporary adjustments and strategies that used imaging instruments, preferably in the dorsal position. Therapeutic evidence on the association between the instrumental method and diaphragmatic mobility can be controversial. The ultrasound measurements indicated some relevance for different analyses, for pulmonary hyperinflation as well as diaphragm thickness and mobilization, in COPD patients. In particular, the study suggests that the ultrasound technique with B-mode for analysis and M-mode for diaphragmatic excursion be used with a 2 - 5 MHz with the patient in the supine position. However, the methods used to monitor diaphragm excursion should be adapted to the conditions of the patients, and additional investigations of their characteristics should be performed. More selective inclusion criteria and better matching in the samples are very important. In addition, more narrow age, sex and weight categories are important, especially in patients with chronic obstructive pulmonary disease.

Does it make difference to measure diaphragm function with M mode (MM) or B mode (BM)?

Diaphragm dysfunction occurs in mechanically ventilated subjects. Recent literature suggests that diaphragm thickening fraction (DTF) measured by ultrasound can be useful to predict weaning outcome. However, there is no standardized approach in the measurement of diaphragm thickness (DT) and limited data exists comparing different measurement techniques of diaphragm thickness (M mode-MM or B mode-BM). The goal of this study was to compare MM with BM in the measurements of DT and excursion in the ICU subjects. DT measurements were obtained from the right diaphragm during tidal and maximal inspiratory breathing. Three measurements of the DT were taken both in MM and BM and their mean values were calculated. DT was measured during inspiration and expiration and DTF was calculated. Excursion of diaphragm was also measured with MM and BM during tidal and maximal inspiratory breathing. Bias and agreement between the two measurement methods were evaluated with Bland and Altman test. Sixty-two subjects were enrolled in the study. While 25 (40%) subjects were receiving invasive mechanical ventilation, 14 (23%) subjects ventilated noninvasively. There were no significant difference between the measurement results of MM and BM. BM and MM tidal diaphragm measurements during the inspiratory (0.3 ± 0.08 and 0.31 ± 0.08 cm; P = 0.022), expiratory (0.24 ± 0.07 and 0.24 ± 0.07 cm; P = 0.315) phases and tidal DTF were (27 ± 16 and 31 ± 14%, P = 0.089) respectively. Results of our study suggests that except tidal inspiratory diaphragm thickness, all thickness and excursion measurements with MM and BM are very compatible with each other. Further studies are necessarry to confirm our results and to standardize the measurements of diaphragm.