Assessment of diaphragmatic function by ultrasonography: Current approach and perspectives

Stabilising function of the human diaphragm in response to involuntary augmented breaths induced with or without lower-limb movements

NEW FINDINGS

What is the central question of this study? Is the stabilising function of the diaphragm altered differentially in response to involuntary augmented breaths induced with or without lower-limb movements? What is the main finding and its importance? At equivalent levels of ventilation, the diaphragm generated higher passive pressure but moved significantly less during incremental cycle ergometry compared with progressive hypercapnia. Diaphragm excursion velocity and power output did not differ between the two tasks. These findings imply that the power output of the diaphragm during stabilising tasks involving the lower limbs may be preserved via coordinated changes in contractile shortening.

ABSTRACT

Activity of key respiratory muscles, such as the diaphragm, must balance the demands of ventilation with the maintenance of stable posture. Our aim was to test whether the stabilising function of the diaphragm would be altered differentially in response to involuntary augmented breaths induced with or without lower-limb movements. Ten healthy volunteers (age 21 (2) years; mean (SD)) performed progressive CO₂ -rebreathe (5% CO₂ , 95% O₂ ) followed 20 min later by incremental cycle exercise (15-30 W/min), both in a semi-recumbent position. Ventilatory indices, intrathoracic pressures and ultrasonographic measures of diaphragm shortening were assessed before, during and after each task. From rest to iso-time, inspiratory tidal volume and minute ventilation increased two- to threefold. At equivalent levels of tidal volume and minute ventilation, mean inspiratory transdiaphragmatic pressure ( P ¯ di ${\bar P_{{\rm{di}}}}$ ) was consistently higher during exercise compared with CO₂ -rebreathe due to larger increases in gastric pressure and the passive component of P ¯ di ${\bar P_{{\rm{di}}}}$ (i.e., mechanical output due to static contractions), and yet diaphragm excursion was consistently lower. This lower excursion during exercise was accompanied by a reduction in excursion time with no difference in the active component of P ¯ di ${\bar P_{{\rm{di}}}}$ . Consequently, the rates of increase in excursion velocity (excursion/time) and power output (active P ¯ di ${\bar P_{{\rm{di}}}}$ × velocity) did not differ between the two tasks. In conclusion, the power output of the human diaphragm during dynamic lower-limb exercise appears to be preserved via coordinated changes in contractile shortening. The findings may have significance in settings where the ventilatory and stabilising functions of the diaphragm must be balanced (e.g., rehabilitation).

Inter-rater reliability of the measurement of diaphragmatic excursion and fraction of diaphragmatic thickening by ultrasonography in healthy volunteers

BACKGROUND AND OBJECTIVE

To determine the inter-rater reliability in the ultrasonographic (US) measurement of the diaphragmatic excursion (DE) and the diaphragm thickness fraction (DTF) performed by non-medical health professionals in healthy people.

PARTICIPANTS AND METHODS

Prospective observational study in a third level hospital in Cali, Colombia. Measurements were made to 30 healthy volunteers chosen by convenience sampling, without a history of lung diseases, with ages between 18-60 years. A pilot test was previously carried out with 8 healthy volunteers. US measurements of DE, and DTF were based on previously published protocols. Each assessor independently observed several cycles of normal quiet breathing for 3min to establish a baseline. The Intraclass Correlation Index (ICC) was used to evaluate the inter-rater reliability in the measurements of DE and DTF, with 95% confidence intervals and a p<0.05.

RESULTS

Substantial agreement was identified in the measurement of DE in the splenic and hepatic windows because the ICC was greater than 0.6 (p<0.05). The measurement of the DTF in the hepatic window showed slight agreement in both 2D and M modes (p>0.05). In the splenic window, the measurement of the DTF in the 2D mode was found to be moderate agreement and for the M mode a slight agreement was found (p>0.05).

CONCLUSIONS

The diaphragmatic US constitutes a reproducible method with acceptable inter-rater reliability for the measurement of inspiratory/expiratory thickness, and with little reliability for the measurement of DTF.

Sonographic assessment of diaphragmatic thickening and excursion as predictors of weaning success in the intensive care unit: A prospective observational study

Background and Aims

Ultrasonographic assessment of diaphragmatic function can be a useful bedside tool in the weaning and extubation of mechanically ventilated patients, especially in patients with difficult weaning, in whom diaphragmatic weakness is suspected. Thus, this study was planned to assess the role of bedside sonographic assessment of diaphragmatic indices such as diaphragmatic thickening fraction (DTf) and diaphragmatic excursion (DE) in predicting successful extubation or extubation failure in weaning eligible patients by comparing the measurements with outcome.

Methods

This prospective observational study was conducted on 50 mechanically ventilated, weaning-ready patients during the spontaneous breathing trial (SBT). The DE and DTf of patients were noted along with conventional parameters of weaning. Probability value <0.05 was considered statistically significant. Receiver operating characteristic (ROC) curves were used for analysis. Area under the curve (AUC) was measured, and sensitivity and specificity for different cut-off values were estimated.

Results

Out of 50 patients, 15 (30%) had SBT failure and 4 had extubation failure. The group with SBT failure had significantly higher rapid shallow breathing index (RSBI) and airway occlusion pressure (P0.1s), whereas DE and DTf were lower compared to the SBT successful group. Strong correlation existed between RSBI, DTf, DE and P0.1s. DTf of nearly 24% (sensitivity 93.5%, specificity 94.7%) and DE of 1.10 cm (84% sensitivity, 89.5% specificity) were associated with best outcome.

Conclusion

Along with conventional parameters of weaning, sonographic assessment of diaphragmatic parameters can be useful in predicting the success of SBT and in avoiding unnecessary extubation failures and thereby help in achieving a successful weaning outcome.

Postural-respiratory function of the diaphragm assessed by M-mode ultrasonography

OBJECTIVES

The diaphragm changes position and respiratory excursions during postural loading. However, it is unclear how it reacts to lifting a load while breath-holding or breathing with simultaneous voluntary contraction of the abdominal muscles (VCAM). This study analyzed diaphragm motion in healthy individuals during various postural-respiratory situations.

METHODS

31 healthy participants underwent examination of the diaphragm using M-mode ultrasonography, spirometry, and abdominal wall tension (AWT) measurements. All recordings were performed simultaneously during three consecutive scenarios, i.e., 1. Lifting a load without breathing; 2. Lifting a load and breathing naturally; 3. Lifting a load and breathing with simultaneous VCAM.

RESULTS

Using paired-samples t-tests, lifting a load without breathing displaced the diaphragm's expiratory position more caudally (P < .001), with no change noted in the inspiratory position (P = .373). During lifting a load breathing naturally, caudal displacement of the diaphragm's inspiratory position was presented (P < .001), with no change noted in the expiratory position (P = 0.20) compared to tidal breathing. Total diaphragm excursion was greater when loaded (P = .002). Lifting a load and breathing with VCAM demonstrated no significant changes in diaphragm position for inspiration, expiration, or total excursion compared to natural loaded breathing. For all scenarios, AWT measures were greater when lifting a load (P < .001).

CONCLUSION

In healthy individuals, caudal displacement and greater excursions of the diaphragm occurred when lifting a load. The postural function of the diaphragm is independent of its respiratory activity and is not reduced by the increase in AWT.

Respiratory Failure After Supraclavicular Nerve Block in a Patient With a Contralateral Brachial Plexus Injury: A Case Report

CASE

A patient with prior left-sided brachial plexus trauma and associated left phrenic nerve paralysis subsequently developed transient respiratory failure after a contralateral supraclavicular nerve block. Her known left phrenic nerve palsy secondary to her index brachial plexus injury was rediscovered during the workup of her acute respiratory distress, which resulted in an emergent intensive care unit admission.

CONCLUSION

The paralysis of her right phrenic nerve at the time of left-sided regional anesthesia was identified as the etiology of near-complete bilateral diaphragmatic paralysis and respiratory failure.

Neuropathology of distinct diaphragm areas following mid-cervical spinal cord contusion in the rat

BACKGROUND

The diaphragm is innervated by phrenic motoneurons distributed from the third to fifth cervical spinal cord. The rostral to caudal phrenic motoneuron pool segmentally innervates the ventral, medial, and dorsal diaphragm.

PURPOSE

The present study was designed to investigate the physiological and transcriptomic mechanism of neuropathology of distinct diaphragm areas following mid-cervical spinal cord injury.

STUDY DESIGN

In vivo animal study.

METHODS

Electromyograms and transcriptome of the ventral, medial, and dorsal diaphragm were examined in rats that received cervical laminectomy or mid-cervical spinal cord contusion in the acute (ie, 1-3 days) or subchronic (ie, ∼14 days) injury stages.

RESULTS

Mid-cervical spinal cord contusion significantly attenuated the inspiratory bursting amplitude of the dorsal diaphragm but not the ventral or medial diaphragm. Moreover, the discharge onset of the dorsal diaphragm was significantly delayed compared with that of the ventral and medial diaphragm in contused rats. Transcriptomic analysis revealed a robust change in gene expression in the ventral diaphragm compared with that in the dorsal diaphragm. Specifically, enrichment analysis of differentially expressed genes demonstrated that the cell cycle and immune response were significantly upregulated, whereas several metabolic pathways were downregulated, in the ventral diaphragm of acutely contused rats. However, no significant Kyoto Encyclopedia of Genes and Genomes pathway was altered in the dorsal diaphragm.

CONCLUSIONS

These results suggest that mid-cervical spinal cord injury has different impacts on the physiological and transcriptomic responses of distinct diaphragm areas.

CLINICAL SIGNIFICANCE

Future therapeutic strategies can consider applying different therapies to distinct diaphragm areas following cervical spinal cord injury. Additionally, confirmation of activities across different diaphragm areas may provide a critical reference for the placement of diaphragmatic pacing electrodes.

Ultrasound imaging of diaphragmatic motion

The diaphragm is the key muscle of respiration, especially in infants. Diaphragmatic dysfunction and paralysis can have significant implications for medical management and treatment, and they can be challenging to diagnose by clinical parameters alone. Multiple imaging modalities are useful for assessing the diaphragm, but US - specifically M-mode US - offers several distinct advantages and few limitations compared to fluoroscopy, radiography, CT and MRI. The purpose of this manuscript is to discuss the pathophysiology of the diaphragm, review common indications for dynamic diaphragmatic US, describe optimal imaging technique, and discuss how to avoid imaging pitfalls.

Intra-Rater Reliability of Shear Wave Elastography for the Quantification of Respiratory Muscles in Adolescent Athletes

The aim of this study was to assess the intra-rater reliability and agreement of diaphragm and intercostal muscle elasticity and thickness during tidal breathing. The diaphragm and intercostal muscle parameters were measured using shear wave elastography in adolescent athletes. To calculate intra-rater reliability, intraclass correlation coefficient (ICC) and Bland-Altman statistics were used. The reliability/agreement for one-day both muscle measurements (regardless of probe orientation) were at least moderate. During the seven-day interval between measurements, the reliability of a single measurement depended on the measured parameter, transducer orientation, respiratory phase, and muscle. Excellent reliability was found for diaphragm shear modulus at the peak of tidal expiration in transverse probe position (ICC_3.1 = 0.91-0.96; ICC₃.₂ = 0.95), and from poor to excellent reliability for the intercostal muscle thickness at the peak of tidal inspiration with the longitudinal probe position (ICC_3.1 = 0.26-0.95; ICC₃.₂ = 0.15). The overall reliability/agreement of the analysed data was higher for the diaphragm measurements (than the intercostal muscles) regardless of the respiratory phase and probe position. It is difficult to identify a more appropriate probe position to examine these muscles. The shear modulus/thickness of the diaphragm and intercostal muscles demonstrated good reliability/agreement so this appears to be a promising technique for their examination in athletes.

The role of diaphragmatic thickness measurement in weaning prediction and its comparison with rapid shallow breathing index: a single-center experience

Background: Acute respiratory failure (ARF) is commonly managed with invasive mechanical ventilation (IMV). The majority of the time that a patient spends on IMV is in the process of weaning. Prediction of the weaning outcome is of paramount importance, as untimely/delayed extubation is associated with a high risk of mortality. Diaphragmatic ultrasonography is a promising tool in the intensive care unit, and its utility in predicting the success of weaning remains understudied.Methods: In this prospective-observational study, we recruited 54 ARF patients on IMV, along with 50 healthy controls. During a spontaneous breathing trial, all subjects underwent diaphragmatic ultrasonography along with a rapid shallow breathing index (RSBI) assessment.Results: The mean age was 41.8±17.0 and 37.6±10.5 years among the cases and control group, respectively. Demographic variables were broadly similar in the two groups. The most common cause of ARF was obstructive airway disease. The average duration of IMV was 5.41±2.81 days. Out of 54 subjects, 45 were successfully weaned, while nine patients failed weaning. Age, body mass index, and severity of disease were similar in the successful and failed weaning patients. The sensitivity in predicting successful weaning of percent change in diaphragmatic thickness (Δtdi%) >29.71% was high (93.33%), while specificity was 66.67%. The sensitivity and specificity of mean diaphragmatic thickness (tdi) end-expiratory >0.178 cm was 60.00% and 77.78%, respectively. RSBI at 1 minute of <93.75 had an equally high sensitivity (93.33%) but a lower specificity (22.22%). Similar results were also found for RSBI measured at 5 minutes.Conclusions: During the weaning assessment, the purpose is to minimize both premature as well as delayed extubation. We found that diaphragmatic ultrasonography, in particular Δtdi%, is better than RSBI in predicting weaning outcomes.

Diaphragm dysfunction after severe COVID-19: An ultrasound study

Background

SARS-CoV-2 infection can impair diaphragm function at the acute phase but the frequency of diaphragm dysfunction after recovery from COVID-19 remains unknown.

Materials and methods

This study was carried out on patients reporting persistent respiratory symptoms 3–4 months after severe COVID-19 pneumonia. The included patients were selected from a medical consultation designed to screen for recovery after acute infection. Respiratory function was assessed by a pulmonary function test, and diaphragm function was studied by ultrasonography.

Results

In total, 132 patients (85M, 47W) were recruited from the medical consultation. During the acute phase of the infection, the severity of the clinical status led to ICU admission for 58 patients (44%). Diaphragm dysfunction (DD) was detected by ultrasonography in 13 patients, two of whom suffered from hemidiaphragm paralysis. Patients with DD had more frequently muscle pain complaints and had a higher frequency of prior cardiothoracic or upper abdominal surgery than patients with normal diaphragm function. Pulmonary function testing revealed a significant decrease in lung volumes and DLCO and the dyspnea scores (mMRC and Borg10 scores) were significantly increased in patients with DD. Improvement in respiratory function was recorded in seven out of nine patients assessed 6 months after the first ultrasound examination.

Conclusion

Assessment of diaphragm function by ultrasonography after severe COVID-19 pneumonia revealed signs of dysfunction in 10% of our population. In some cases, ultrasound examination probably discovered an un-recognized pre-existing DD. COVID-19 nonetheless contributed to impairment of diaphragm function. Prolonged respiratory physiotherapy led to improvement in respiratory function in most patients.

Clinical trial registration

[www.cnil.fr], identifier [#PADS20-207].

Inspiratory and expiratory CT analyses of the diaphragmatic crus in chronic obstructive pulmonary disease

PURPOSE

This study aimed to investigate the association between the results of pulmonary function tests (PFTs) in patients with chronic obstructive pulmonary disease (COPD) and the size of their diaphragmatic crus (DC) using inspiratory and expiratory CT.

MATERIALS AND METHODS

Thirty-three patients who underwent inspiratory and expiratory CT and PFTs between July and December 2019 were studied retrospectively. The short axis, long axis, and cross-sectional area (CSA) of the bilateral DC were measured, and the percentage change of the DC after expiration (% change of DC) in the size was calculated. The correlation between the results of the PFTs (forced expiratory volume in 1 s [FEV₁], FEV₁/forced vital capacity [FVC], and percent predicted FEV₁ [%FEV₁]) and the size and % change of DC was statistically analyzed.

RESULTS

Significant correlations were observed between the short axis of the right and left DC at expiration and PFTs (FEV₁, r = -0.35, -0.48, p = 0.04, .007; FEV₁/FVC, r = -0.52, -0.65, p = 0.002, < .001; %FEV₁, r = -0.56, -0.60, p < 0.001, < 0.001; respectively), between the CSA of the right DC at expiration and PFTs (FEV₁/FVC, r = -0.42, p = 0.01; %FEV₁, r = -0.41, p = 0.017; respectively), and between the % change of the short axis of the left DC and the CSA of the left DC and PFTs (FEV₁, r = 0.64, 0.56, p < 0.001, .001; %FEV₁, r = 0.52, 0.51, p = 0.004, 0.004; respectively). The smaller the short axis of the DC and CSA at expiration and the larger the % change in DC of the CSA, the lower the airflow limitation.

CONCLUSION

There were significant correlations between airflow limitation and the short axis of the bilateral DC at expiration, and the % change in the DC of the CSA. Certain CT measurements of the DC may reflect airflow limitation in patients with COPD.

Ultrasonography in Assessment of Respiratory Muscles Function: A Systematic Review

INTRODUCTION

The purpose of this study was to evaluate the potential utility of respiratory muscles ultrasound (US) imaging for assessing respiratory function and identify US variables that best correlate with pulmonary parameters.

MATERIALS AND METHODS

A search of 5 databases was conducted. Initially, there was no language, study design, or time frame restrictions. All studies assessing the relationship between pulmonary and US parameters were included. Two reviewers independently extracted and documented data regarding to examined population, age, gender, health condition, methodology, US, and pulmonary function measurements. All studies were qualitative synthesis.

RESULTS

A total of 1,272 participants from 31 studies were included. Diaphragm thickness, diaphragm thickening ratio, and diaphragm excursion amplitude were mainly used as US parameters. Forced vital capacity, forced expiratory volume1sec, and maximal inspiratory pressure were mainly used as pulmonary parameters. The relationships between pulmonary and US parameters varied from negligible to strong (depend on examined population and methodology used). Data were not quantitatively synthesis due to high heterogeneity in terms of study design, population examined, and various pulmonary and US parameters.

CONCLUSION

A strong relationship between US measurements and pulmonary parameters was demonstrated in some studies but not others. This review confirmed that US measurements can complement spirometry, but the exact role of the US remains to be confirmed. Further studies using standardized methodology are needed to obtain more conclusive evidence on the usefulness of US for assessing respiratory function.

Prevalence of Diaphragmatic Dysfunction in the Long-Term Acute Care Setting and Its Effects on Ventilator Weaning Outcomes: A Retrospective Cohort Study

OBJECTIVE

To determine the prevalence of undiagnosed diaphragmatic dysfunction in a long-term acute care hospital setting in patients on prolonged mechanical ventilation and its association with weaning outcomes.

DESIGN

This is a single-center, retrospective cohort study including 451 patients on prolonged mechanical ventilation admitted to a long-term acute care hospital facility between 2012 and 2017. Diaphragmatic dysfunction was assessed using fluoroscopy.

RESULTS

Three hundred nineteen patients on prolonged mechanical ventilation were assessed for diaphragmatic dysfunction. Nine patients were diagnosed with diaphragmatic dysfunction before admission. Eighty (72.7%) without diaphragmatic dysfunction were successfully weaned and 30 (27.3%) failed to wean, whereas 51 participants (31.9%) with diaphragmatic dysfunction were successfully weaned and 109 (68.1%) failed to wean (P < 0.001). When analyzing days to wean, the median was 13 days for those with no diaphragmatic dysfunction, 19 days with unilateral diaphragmatic dysfunction, and 28 days with bilateral diaphragmatic dysfunction (P < 0.001). Weaning success was not statistically associated with generalized neuromuscular disorders, age, sex, body mass index, smoking history, or diabetes.

CONCLUSIONS

Diaphragmatic dysfunction was found to be strongly associated with time to wean and weaning success in the long-term acute care hospital setting. Very few patients despite being on prolonged mechanical ventilation were diagnosed with diaphragmatic dysfunction before long-term acute care hospital admission. Given this information, early diagnosis of diaphragmatic dysfunction among prolonged mechanical ventilation patients in the long-term acute care hospital setting is paramount in preventing secondary complications associated with mechanical ventilation.

Comparison of the effects of neostigmine and sugammadex on postoperative residual curarization and postoperative pulmonary complications by means of diaphragm and lung ultrasonography: a study protocol for prospective double-blind randomized controlled trial

Background

Postoperative residual curarization (PORC) may be a potential risk factor of postoperative pulmonary complications (PPCs), and both of them will lead to adverse consequences on surgical patient recovery. The train-of-four ratio (TOFr) which is detected by acceleromyography of the adductor pollicis is thought as the gold standard for the measurement of PORC. However, diaphragm function recovery may differ from that of the peripheral muscles. Recent studies suggested that diaphragm ultrasonography may be useful to reveal the diaphragm function recovery, and similarly, lung ultrasound was reported for the assessment of PPCs in recent years as well. Sugammadex reversal of neuromuscular blockade is rapid and complete, and there appear to be fewer postoperative complications than with neostigmine. This study aims to compare the effects of neostigmine and sugammadex, on PORC and PPCs employing diaphragm and lung ultrasonography, respectively.

Methods/design

In this prospective, double-blind, randomized controlled trial, patients of the American Society of Anesthesiologists Physical Status I–III, aged over 60, will be enrolled. They will be scheduled to undergo arthroplasty under general anesthesia. All patients will be allocated randomly into two groups, group NEO (neostigmine) and group SUG (sugammadex), using these two drugs for reversing rocuronium. The primary outcome of the study is the incidence of PPCs in the NEO and SUG groups. The secondary outcomes are the evaluation of diaphragm ultrasonography and lung ultrasound, performed by an independent sonographer before anesthesia, and at 10 min and 30 min after extubation in the post-anesthesia care unit, respectively.

Discussion

Elimination of PORC is a priority at the emergence of anesthesia, and it may be associated with reducing postoperative complications like PPCs. Sugammadex was reported to be superior to reverse neuromuscular blockade than neostigmine. Theoretically, complete recovery of neuromuscular function should be indicated by TOFr > 0.9. However, the diaphragm function recovery may not be the same matter, which probably harms pulmonary function. The hypothesis will be proposed that sugammadex is more beneficial than neostigmine to reduce the incidence of PPCs and strongly favorable for the recovery of diaphragm function in our study setting.

Trial registration

ClinicalTrials.gov NCT05040490. Registered on 3 September 2021

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06328-3.

Number of attempts required by emergency physicians to achieve competency in diaphragmatic ultrasound imaging

PURPOSE

This research aimed to determine the number of attempts that emergency physicians need to become proficient in undertaking diaphragmatic ultrasound imaging.

METHODS

A prospective observational study was conducted at the emergency department (ED) of a tertiary-care university hospital. Sixteen emergency physicians were each required to obtain a set of images of the right hemidiaphragm of five dyspneic patients using both diaphragmatic excursion and thickness techniques. The images were subsequently reviewed by a specialist using American College of Emergency Physician guidelines. If the evaluations of a physician did not reach the expected standard, the physician was to be given feedback and requested to collect images from another five patients. The process was to be repeated until such time as the images obtained by the physician were deemed to be up to standard.

RESULTS

Eighty patients, twelve emergency medicine residents, and four attending physicians were enrolled. Following a didactic session on diaphragmatic ultrasound imaging and its interpretation, practicing on five patients proved sufficient to achieve an adequate level of competency in conducting diaphragmatic ultrasound examinations.

CONCLUSION

Practicing on five patients is sufficient for emergency physicians to achieve an adequate level of competency in conducting right-sided diaphragmatic ultrasound examinations.

Diaphragm and Phrenic Nerve Ultrasound in COVID-19 Patients and Beyond: Imaging Technique, Findings, and Clinical Applications

The diaphragm, the principle muscle of inspiration, is an under-recognized contributor to respiratory disease. Dysfunction of the diaphragm can occur secondary to lung disease, prolonged ventilation, phrenic nerve injury, neuromuscular disease, and central nervous system pathology. In light of the global pandemic of coronavirus disease 2019 (COVID-19), there has been growing interest in the utility of ultrasound for evaluation of respiratory symptoms including lung and diaphragm sonography. Diaphragm ultrasound can be utilized to diagnose diaphragm dysfunction, assess severity of dysfunction, and monitor disease progression. This article reviews diaphragm and phrenic nerve ultrasound and describes clinical applications in the context of COVID-19.

Ultrasound-Derived Diaphragm Contractile Reserve as a Marker of Clinical Status in Patients With Cystic Fibrosis

Introduction: In patients with cystic fibrosis (CF), the monitoring of respiratory muscle activity using electromyography can provide information on the demand-to-capacity ratio of the respiratory system and act as a clinical marker of disease activity, but this technique is not adapted to routine clinical care. Ultrasonography of the diaphragm could provide an alternative, simpler and more widely available alternative allowing the real-time assessment of the diaphragm contractile reserve (DCR), but its relationship with recognized markers of disease severity and clinical outcomes are currently unknown.

Methods: Stable patients with CF were prospectively recruited. Diaphragm ultrasound was performed and compared to forced expiratory volume in 1 s (FEV₁), residual volume (RV), handgrip strength, fat-free mass index (FFMI), serum vitamin levels, dyspnea levels and rate of acute exacerbation (AE). Diaphragm activity was reported as DCR (the ratio of tidal-to-maximal thickening fractions, representing the remaining diaphragm contractility available after tidal inspiration) and TFmax (representing maximal diaphragm contractile strength). Inter-observer reliability of the measurement of DCR was evaluated using intra-class correlation analysis.

Results: 110 patients were included [61 males, median (interquartile range), age 31 (27–38) years, FEV₁ 66 (46–82)% predicted]. DCR was significantly correlated to FEV₁ (rho = 0.46, p < 0.001), RV (rho = −0.46, p < 0.001), FFMI (rho = 0.41, p < 0.001), and handgrip strength (rho = 0.22, p = 0.02), but TFmax was not. In a multiple linear regression analysis, both RV and FFMI were independent predictors of DCR. DCR, but not TFmax, was statistically lower in patients with > 2 exacerbations/year (56 ± 25 vs. 71 ± 17%, p = 0.001) and significantly lower with higher dyspnea levels. A ROC analysis showed that DCR performed better than FEV₁ (mean difference in AUROC 0.09, p = 0.04), RV (mean difference in AUROC 0.11, p = 0.03), and TFmax at identifying patients with an mMRC score > 2. Inter-observer reliability of DCR was high (ICC = 0.89, 95% CI 0.84–0.92, p < 0.001).

Conclusion: In patients with CF, DCR is a reliable and non-invasive marker of disease severity that is related to respiratory and extra-pulmonary manifestations of the disease and to clinical outcomes. Future studies investigating the use of DCR as a longitudinal marker of disease progression, response to interventions or target for therapy would further validate its translation into clinical practice.

Diaphragmatic excursion by ultrasound: reference values for the normal population; a cross-sectional study in Egypt

Background

Measurement of diaphragmatic motion by ultrasound is being utilized in different aspects of clinical practice. Defining reference values of the diaphragmatic excursion is important to identify those with diaphragmatic motion abnormalities. This study aimed to define the normal range of diaphragmatic motion (reference values) by Mmode ultrasound for the normal population.

Methods

Healthy volunteers were included in this study. Those with comorbidities, skeletal deformity, acute or chronic respiratory illness were excluded. Diaphragmatic ultrasound in the supine position was performed using a lowfrequency probe. The B-mode was applied for diaphragmatic identification, and the M-mode was employed for the recording of the amplitude of diaphragm contraction during quiet breathing, deep breathing and sniffing.

Results

The study included 757 healthy subjects [478 men (63.14%) and 279 women (36.86%)] with normal spirometry and negative history of previous or current respiratory illness. Their mean age and BMI were 45.17 ±14.84 years and 29.36±19.68 (kg/m²). The mean right hemidiaphragmatic excursion was 2.32±0.54, 5.54±1.26 and 2.90±0.63 for quiet breathing, deep breathing and sniffing, respectively, while the left hemidiaphragmatic excursion was 2.35±0.54, 5.30±1.21 and 2.97±0.56 cm for quiet breathing, deep breathing and sniffing, respectively. There was a statistically significant difference between right and left diaphragmatic excursion among all studied subjects. The ratio of right to left diaphragmatic excursion during quiet breathing was (1.009±0.19); maximum 181% and minimum 28%. Only 19 cases showed a right to left ratio of less than 50% (5 men and 14 women). The diaphragmatic excursion was higher in males than females. There was a significant difference in diaphragmatic excursion among age groups. Age, sex and BMI significantly affected the diaphragmatic motion.

Conclusions

Diaphragmatic excursion values presented in this study can be used as reference values to detect diaphragmatic dysfunction in clinical practice. Diaphragmatic motion is affected by several factors including age, sex and body mass index.

Evaluation of Diaphragm Thickness and Stiffness Using Ultrasound and Shear-Wave Elastography

ABSTRACT

The purposes of this study are to measure the thickness and stiffness of diaphragm in association with the respiratory cyclus and to assess the reproducibility of these measurements. Forty individuals who are volunteered for participating diaphragm evaluation were included in the study. Two radiologists with 14 and 15 years of experiences in abdominal ultrasound performed all examinations independently. Furthermore, 8 chronic obstructive pulmonary disease (COPD) patients were examined by only the first radiologist. Gray scale and shear-wave elastography imaging of only the right hemidiaphragm of all participants were performed. Thickness and stiffness of diaphragm were measured at the peak inspiration and end expiration phases. Intraclass correlation coefficients test was used to assess the interobserver agreement. The thickness and stiffness of diaphragm significantly increased with inspiration (P < 0.001). The mean ± SD stiffness of diaphragm in peak inspiration and end expiration phases was 51.84 ± 16.83 kPa and 38.49 ± 9.42 kPa, respectively, for the first radiologist and 49.61 ± 13.83 kPa and 37.52 ± 10.71 kPa, respectively, for the second radiologist. Intraclass correlation coefficient values for diaphragm stiffness were 0.667 and 0.736 in peak inspiration and end expiration phases, respectively. In COPD patients, there was no significant difference between stiffness measurements of respiratory phases. In conclusion, the current study revealed that diaphragm thickness and stiffness increase at inspiration, and these measurements are slightly more reproducible at the end of expiration. However, diaphragm stiffness changes between respiratory phases may not be valid for COPD patients, and this may be related to loss of force-generating capacity of diaphragm in COPD patients.

Early changes in left ventricular myocardial function by 2D speckle tracking layer-specific technique in neonates with hyperbilirubinemia

Background

Hyperbilirubinemia (HBN) can cause myocardial injury in neonates. Advancement in myocardial deformation imaging allows the detection of subclinical changes in myocardial contractility. The present study aimed to evaluate the changes in left ventricular contractility in newborns with hyperbilirubinemia by 2D speckle tracking imaging (STI).

Methods

A group of 134 neonates who reached the diagnostic level of HBN as the HBN group was selected. The control group included 56 healthy newborns. The interventricular septum, anterior partition, anterior wall, sidewall, posterior wall, and inferior wall were separated into the basal, middle, and apical segments. In each segment, speckle tracking analysis was performed in the subintimal, middle, and subadventitial myocardium. The overall longitudinal strain of the myocardium in different ventricular walls and segments and global longitudinal strain (GLS) were computed. At the same time, the laboratory results of blood gas analysis, blood routine tests, liver function, and myocardial enzyme spectrum in HBN neonates were collected and correlated with the left ventricular stratified strain parameters.

Results

The gradient of the left ventricular GLS had the same characteristics in both groups of newborns. There was a decreasing trend of longitudinal strain (LS) from the intima to the adventitia (i.e., GLSendo > GLSmid > GLSepi). This gradient was also present in stratified LS in each myocardial segment (P<0.001). The LS showed an increasing trend from the basal to the apical segment (P<0.001). The LS of the ventricular septum, anterior wall (or anterior septum), inferior wall, lateral wall, and posterior wall showed a decreasing trend (P<0.001). Stratified strain parameters of the ventricular wall (i.e., the 3-layer myocardium: LSendo-SEPT, LSmid-SEPT, and LSepi-SEPT) were all significantly lower in the HBN group than in the control group (P=0.019, P=0.019, and P=0.023, respectively). LSedo-ANT, LSmid-ANT, and LSepi-ANT were also reduced, and the difference between LSendo-ANT and LSepi-ANT was statistically significant. The segmental stratified strain parameters (i.e., the apical 3-layer myocardium: LSepi-a, LSmid-a, and LSepi-a) decreased, and the difference in LSepi-a was statistically significant (P=0.043). Overall strain parameters (i.e., the 3-layer myocardial overall strain: GLSendo, GLSmid, and GLSepi) were reduced, but the difference was not statistically significant (P=0.612, P=0.653, and P=0.585, respectively). The subclinical changes in systolic function in the HBN group, reflected by the parameters of longitudinal myocardial strain, correlate to some extent with multiple results of laboratory tests.

Conclusions

2DSTI stratified strain technology can quantitively evaluate changes in the LS of the left ventricle in different ventricular walls, wall segments, and layers of the myocardium.

Effects of Dexmedetomidine on Diaphragm Activity Measured by Ultrasonography in Spontaneously Breathing Patients

Background: Diaphragm movement is well correlated with inspired volume of the lung. Dexmedetomidine (DEX) has less effect on respiratory functions than other sedatives. The objective of this study was to investigate diaphragmatic movement using ultrasound (US) during DEX infusion for sedation in spontaneously breathing patients undergoing unilateral upper limb surgery. Methods: A total of 33 consecutive patients were enrolled in this study. Patients were sedated using DEX with ipsilateral axillary brachial nerve plexus block. Diaphragmatic activity was evaluated using diaphragmatic thickening at end-inspiration (TEI), diaphragmatic thickening at end-expiration (TEE), and diaphragmatic thickening fraction (DTF) measured by diaphragmatic US at three time-points; T0, baseline; T1, after DEX sedation; and T2, after DEX recovery. Supplementary oxygen was applied with a simple mask at 5 L/min. Peripheral oxygen saturation (SpO₂), end tidal CO₂ (EtCO₂), and respiratory rate (RR) were recorded. Results: TEI and TEE showed no significant changes during the study period (P = 0.394 and P = 0.205, respectively). DTF was maintained at both T0 and T1 (P = 1.000). At recovery after DEX infusion discontinued, DTF was increased by 3.85%, although such increase was not statistically significant (T0 vs. T2, P = 0.525). SpO₂ remained above 99% and EtCO₂ remained below 36 mmHg. Desaturation episodes were not observed during the study period. Conclusions: Results of this study showed that DEX sedation did not affect the diaphragmatic movement in situation of decreased RR induced by DEX. This finding implies that DEX-induced sedation does not result in clinically significant respiratory depression.

Ultrasonographic evaluation of incidence of diaphragmatic paralysis following different volumes of supraclavicular brachial plexus block- A prospective randomized double blinded study

Background:

Ipsilateral diaphragmatic paralysis occurs following supraclavicular blocks such as interscalene blocks, supposedly attributable to the backward diffusion of the local anesthetic (LA) inside the neural sheath. Hence, we have made an attempt to assess diaphragmatic paralysis with ultrasonogram (US) following different volumes of supraclavicular brachial plexus blocks (SCB).

Aim:

To compare the incidence of diaphragmatic paralysis with different volumes of supraclavicular brachial plexus block using ultrasonogram.

Methods:

Sixty patients with American Society of Anesthesiologists (ASA) Physical Status I and II were randomized to receive 20, 25, or 30 mL of 0.375% bupivacaine in a double-blinded fashion, and supraclavicular block was performed using ultrasound guidance in an in-plane technique. Diaphragmatic excursion and velocity were studied using a curvilinear 3.5 MHz transducer before and 20 min after giving the block.

Results:

The incidence of reduction in diaphragmatic excursion and velocity in the group receiving 30 mL was 45% and 45%, respectively, which was higher, whereas it was 47.5% and 32.5% in the 25 mL group and 40% and 25% in the 20 mL group, respectively, which were still lower. Pre- and post-block data were studied using T-test, Kruskal–Wallis test, and Mann–Whitney U test. The probability of reduction in diaphragmatic excursion and velocity in each group was <0.05, which was statistically significant.

Conclusion:

Our results suggest that there is a greater risk of inadvertent phrenic nerve blockade even in supraclavicular brachial plexus block. The resulting hemidiaphragmatic paralysis is volume dependent, and the overall incidence is higher at greater volumes. Hence, caution is required against compromised perioperative lung function in patients with preexisting cardiorespiratory dysfunction.

Changes in Diaphragmatic Function Induced by an Increased Inspiratory Load Experienced by Military Divers: An Ultrasound Study

Background: Inspiratory loading is experienced by military divers when they use rebreather device. Our objective was to assess the changes in diaphragm function induced by an increase in inspiratory load at values similar to those experienced by divers in real life.

Methods: We recorded the excursion and the thickness of the right hemidiaphragm in 22 healthy male volunteers under inspiratory load conditions, using ultrasound in B- and M-mode. The measurements were performed at tidal volume and during breathing at 50% of inspiratory capacity. The breathing rate was regulated and similar in the various sessions with and without load.

Results: The rebreather device used by French military divers leads to an increase in inspiratory load of close to 30 cmH₂O. Consequently, the session under load was performed using a device set to this threshold. Significant increases in the excursion and the thickening fraction of the diaphragm were observed between the sessions at tidal volume and at high volume. With addition of the inspiratory load, the excursion of the right hemidiaphragm increased significantly from 2.3 to 3.4cm at tidal volume and from 3.9 to 4.7cm at high volume. The thickening fraction increased significantly from 30.4 to 76.6% at tidal volume and from 70 to 123% at high volume. The statistical analysis demonstrated that assessment of the changes of the thickening fraction during breathing at tidal volume was the most relevant marker to assess the impact of the inspiratory load on the diaphragm.

Conclusion: Diaphragm ultrasound can be used to assess the changes in the diaphragm contraction pattern secondary to an increase in the respiratory load that can be generated by use a diving apparatus. The recording of the changes of the motion, and more importantly of the thickness of the diaphragm, during the breathing cycle is able to provide relevant information regarding the inspiratory load.

The Feasibility of Ultrasonographic Diaphragmatic Excursion in Healthy Dogs: Effect of Positioning, Diaphragmatic Location, and Body Weight of Dogs

Diaphragmatic excursion (DE) has been utilized for detecting respiratory related problems in humans. However, several factors should be considered such as the ultrasound technique and factors intrinsic to patients. Nevertheless, knowledge of the effect of these factors on DE in dogs is still lacking. The aim of this study was to evaluate the proper ultrasound technique by varying postures and diaphragmatic locations for DE measurement and to explore intrinsic factors such as diaphragmatic sides, sex, and body weight of dogs on DE. The prospective, analytic, cross-sectional study included 44 healthy dogs; 12 beagles and 32 dogs of other breeds. The experiment was divided into (i) an exploration of the proper ultrasound technique by varying postures (supine, standing, and recumbent in each of the right and left lateral positions), diaphragmatic locations (middle crus and proximal to the last rib), and diaphragmatic sublocations (xiphoid, mid, and proximal rib) for detection of DE and (ii) the evaluation of canine intrinsic factors affecting DE. The results show that the mid-diaphragmatic sublocation in the middle crus area in almost all positions revealed the highest percentage DE detection. However, DEs were revealed to be more accessible in the supine position. There was no significant difference in DE between the right and the left diaphragms or between the sexes of beagle dogs. However, body weight was significantly correlated with the DE among dogs of various sizes. In conclusion, the posture of the dogs and the diaphragmatic location can affect DE evaluation. Neither sex nor diaphragmatic side had an influence, but body weight was revealed as a major factor in DE in dogs.

Ultrasonic particles: An approach for targeted gene delivery

Gene therapy has been widely investigated for the treatment of genetic, acquired, and infectious diseases. Pioneering work utilized viral vectors; however, these are suspected of causing serious adverse events, resulting in the termination of several clinical trials. Non-viral vectors, such as lipid nanoparticles, have attracted significant interest, mainly due to their successful use in vaccines in the current COVID-19 pandemic. Although they allow safe delivery, they come with the disadvantage of off-target delivery. The application of ultrasound to ultrasound-sensitive particles allows for a direct, site-specific transfer of genetic materials into the organ/site of interest. This process, termed ultrasound-targeted gene delivery (UTGD), also increases cell membrane permeability and enhances gene uptake. This review focuses on the advances in ultrasound and the development of ultrasonic particles for UTGD across a range of diseases. Furthermore, we discuss the limitations and future perspectives of UTGD.

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.

Ultrasonographic assessment of diaphragmatic contraction and relaxation properties: correlations of diaphragmatic displacement with oesophageal and transdiaphragmatic pressure

Transdiaphragmatic (Pdi) and oesophageal pressures (Pes) are useful in understanding the pathophysiology of the respiratory system. They provide insight into respiratory drive, intrinsic positive end-expiratory pressure, diaphragmatic fatigue and weaning failure.

Klinische Neurophysiologie auf der pädiatrischen Intensivstation

Auf pädiatrischen Intensivstationen kommt es häufig zum Einsatz neurophysiologischer Untersuchungsmethoden. Bei akuten Enzephalopathien oder in Situationen, in denen ein hohes Risiko für epileptische Anfälle besteht, werden verschiedene Varianten des EEGs verwendet. Bei Hinweisen auf neuromuskuläre Erkrankungen sind die Neurographie, die evozierten Potentiale, und die Elektromyographie die entscheidenden diagnostischen Methoden. Im Falle erworbener Hirnschädigungen wie z. B. nach Reanimationsereignissen oder bei Schädel-Hirn-Traumata können sowohl das EEG, als auch die evozierten Potentiale zur Prognoseabschätzung verwendet werden. Die Umstände auf der Intensivstation erschweren bei all diesen Methoden die Durchführung und die Interpretation. Viele Patienten werden mit Medikamenten behandelt, die die Untersuchungsergebnisse beeinflussen (insbesondere Sedativa und Muskelrelaxantien). Elektronische Geräte, z. B. für die Beatmung der Patienten, können zum Auftreten deutlicher Artefakte bei den neurophysiologischen Untersuchungen führen. Im vorliegenden Artikel werden die Einsatzbereiche neurophysiologischer Methoden auf pädiatrischen Intensivstationen beschrieben und auf Details bei der Anwendung eingegangen.

Non-Invasive Respiratory Assessment in Duchenne Muscular Dystrophy: From Clinical Research to Outcome Measures

Ventilatory failure, due to the progressive wasting of respiratory muscles, is the main cause of death in patients with Duchenne muscular dystrophy (DMD). Reliable measures of lung function and respiratory muscle action are important to monitor disease progression, to identify early signs of ventilatory insufficiency and to plan individual respiratory management. Moreover, the current development of novel gene-modifying and pharmacological therapies highlighted the urgent need of respiratory outcomes to quantify the effects of these therapies. Pulmonary function tests represent the standard of care for lung function evaluation in DMD, but provide a global evaluation of respiratory involvement, which results from the interaction between different respiratory muscles. Currently, research studies have focused on finding novel outcome measures able to describe the behavior of individual respiratory muscles. This review overviews the measures currently identified in clinical research to follow the progressive respiratory decline in patients with DMD, from a global assessment to an individual structure–function muscle characterization. We aim to discuss their strengths and limitations, in relation to their current development and suitability as outcome measures for use in a clinical setting and as in upcoming drug trials in DMD.

A narrative review of diaphragmatic ultrasound in pediatric critical care

The use of point of care ultrasound (POCUS) at the bedside has increased dramatically within emergency medicine and in critical care. Applications of POCUS have spread to include diaphragmatic assessments in both adults and children. Diaphragm POCUS can be used to assess for diaphragm dysfunction (DD) and atrophy or to guide ventilator titration and weaning. Quantitative, semi-quantitative and qualitative measurements of diaphragm thickness, diaphragm excursion, and diaphragm thickening fraction provide objective data related to DD and atrophy. The potential for quick, noninvasive, and repeatable bedside diaphragm assessments has led to a growing amount of literature on diaphragm POCUS. To date, there are no reviews of the current state of diaphragm POCUS in pediatric critical care. The aims of this narrative review are to summarize the current literature regarding techniques, reference values, applications, and future innovations of diaphragm POCUS in critically ill children. A summary of current practice and future directions will be discussed.

A Case Report of Bilateral Phrenic Nerve Dysfunction After Unilateral Supraclavicular Brachial Plexus Block: Unveiling Preexisting Diaphragmatic Dysfunction

A 48-year-old woman with a history of cardiac surgery developed severe dyspnea and anxiety following right-sided supraclavicular nerve block for hand surgery. In this case, right phrenic nerve blockade from a supraclavicular block unmasked a subclinical hemidiaphragmatic paresis from phrenic nerve injury on the left, the latter likely due to previous cardiac surgery. When performing brachial plexus block at or above the clavicle, particularly for prior cardiothoracic surgical patients, anesthesiologists can easily, quickly, and inexpensively use point-of-care ultrasound to assess whether any degree of phrenic nerve dysfunction exists on the contralateral side, as patients may be asymptomatic at baseline.

Diaphragmatic motion recorded by M-mode ultrasonography: limits of normality

Chest ultrasonography has proven to be useful in the diagnosis of diaphragm dysfunction. The aim of the present study was to determine the normal values of the motion of both hemidiaphragms recorded by M-mode ultrasonography.

Healthy volunteers were studied while in a seated position. Diaphragmatic excursions and diaphragm profiles were measured during quiet breathing, voluntary sniffing and deep breathing. Diaphragmatic excursions were assessed by M-mode ultrasonography, using an approach perpendicular to the posterior part of the diaphragm. Anatomical M-mode was used for the recording of the complete excursion during deep breathing.

The study included 270 men and 140 women. The diaphragmatic motions during quiet breathing and voluntary sniffing were successfully recorded in all of the participants. The use of anatomical M-mode was particularly suitable for measurement of the entire diaphragmatic excursion during deep breathing. The statistical analysis showed that the diaphragmatic excursions were larger in men compared to women, supporting the determination of normal values based on sex. The lower and upper limits of normal excursion were determined for men and women for both hemidiaphragms during the three manoeuvres that were investigated. The lower limits of normal diaphragmatic excursions during deep breathing should be used to detect diaphragmatic hypokinesia, i.e. 3.3 and 3.2 cm in women and 4.1 and 4.2 cm in men for the right and the left sides, respectively.

The normal values of the diaphragmatic motion and the lower and upper limits of normal excursion can be used by clinicians to detect diaphragmatic dysfunction.

These normal values of diaphragmatic motion, and the lower and upper limits of normal excursion, can be used by physicians to detect diaphragm hypokinesia and hyperkinesia, and thus diagnose diaphragmatic dysfunctionhttps://bit.ly/35R9OFk

A Novel Thoracic Ultrasound Measurement After Congenital Diaphragmatic Hernia Repair Identifies Decreased Diaphragmatic Excursion Associated With Adverse Respiratory and Surgical Outcomes

Background and Aim: Congenital diaphragmatic hernia (CDH) is a rare defect often associated with pulmonary hypoplasia and abnormal pulmonary vascular development. Even after successful hernia repair, pulmonary disease may persist into adulthood. Impaired diaphragmatic motility may lead to compromised respiratory function long after index repair. This study investigates whether a novel ultrasound measurement, the diaphragmatic excursion ratio, can be a simple and non-invasive method to evaluate routine diaphragmatic motion after CDH repair, and whether it correlates with adverse surgical and respiratory outcomes. Materials and Methods: A cross-sectional study was conducted in consecutive patients who presented at medium-term follow-up visit between December 2017 and December 2018 after CDH repair at single pediatric hospital. Transthoracic ultrasound was performed with craniocaudal diaphragmatic excursion measured bilaterally during routine breathing. Diaphragmatic excursion ratios (diaphragmatic excursion of repaired vs. unrepaired side) were calculated and retrospectively compared with clinical data including demographics, length of stay, respiratory adjuncts, oral feeding, and need for gastrostomy. Results: Thirty-eight patients (median age at ultrasound, 24 months, interquartile range 11-60) were evaluated. Nine patients underwent primary repair, 29 had non-primary repair (internal oblique muscle flap or mesh patch). Patients with a diaphragmatic excursion ratio below the median (0.54) had longer hospital stays (median 77 vs. 28 days, p = 0.0007) more ventilator days (median 16 vs. 9 days, p =0.004), and were more likely to have been discharged on oxygen (68 vs. 16%, p = 0.001). They were also less likely to be exclusively taking oral feeds at 1-year post-surgery (37 vs. 74%, p = 0.02) and more likely to require a gastrostomy tube in the first year of life (74 vs. 21%, p = 0.003). Conclusions: Transthoracic ultrasound after CDH repair is practical method to assess diaphragm motion, and decreased diaphragm excursion ratio is associated with worse respiratory outcomes, a longer length of stay, and dependence on gastrostomy tube feeding within 1 year. Further prospective studies may help validate this novel ultrasound measurement and offer prognostic value.

The Use of Diaphragm Ultrasonography in Pulmonary Physiotherapy of COPD Patients: A Literature Review

There is potentially a broad range of patient populations in which ultrasound imaging (US) might be beneficial form of physiotherapy process support. Among them, the group of patients with chronic obstructive pulmonary disease (COPD) is of great importance, as in this individuals the diaphragm dysfunction is frequently observed. Pulmonary physiotherapy often includes techniques which are intended to influence the diaphragm muscle but its anatomy does not allow for variety of techniques to assess function. Lack of easily available and reliable measures complicates outcomes interpretation and makes decision-making process difficult. A review of the electronic literature was conducted to identify studies related to the US assessment of physiotherapy process and its outcome in COPD patients. As a consequence, seven papers were identified. Based on the results obtained, it can be concluded that the diaphragm excursion is US measure that is most often described in context of diaphragm-related physiotherapy in COPD patients. The methodology applied, however, varies greatly making it difficult to compare results. Thus, developing standards of outcome assessment methods and therapy monitoring systems which are supported by evidence should be of paramount importance. Future studies could also focus on identifying which components of physiotherapeutic diaphragm-targeted approach provide acceptable level of evidence.