Respiratory muscle ultrasonography evaluation and its clinical application in stroke patients: A review

The investigation of ultrasound to assess lateral abdominal wall activation with different types of core exercises

BACKGROUND

Core training is the foundation of physical exercise. The activation of the lateral abdominal wall (LAW) muscles in the core muscles, particularly the transversus abdominal (TrA) muscles, has a stabilizing effect on the chest and abdomen. Therefore, we need to focus on the training effect of the TrA. There are many ways to measure the LAW. Ultrasound can assess the effect of training in real time and intuitively. Therefore, we intend to evaluate the activation of the LAW in different types of core training using ultrasound, to determine the best movements that can activate the TrA and train the core muscles.

METHODS

22 healthy subjects (male 10, female 12, age 22.82 ± 0.98, BMI 20.78 ± 2.27) were included. The subjects were given the following instructions to perform breathing exercises at different positions: calm breathing and deep breathing at 0° hip flexion and 0° knee flexion; calm breathing, deep breathing, abdominal crunches and ball crunches at 45° hip flexion and 90° knee flexion; and calm breathing, deep breathing, abdominal crunches and ball crunches at 90° hip flexion and 90° knee flexion. The muscle thicknesses of the bilateral transversus abdominis (TrA), internal oblique (IO), external oblique (EO), and LAW muscles were measured using ultrasonography at the end of expiration during the above movements.

RESULTS

(1) The action with the greatest contraction ratio of the TrA was deep exhalation, which was significantly greater than crunch and ball crunch; (2) During deep exhalation, the TrA had the greatest contraction ratio, significantly greater than the IO and EO. (3) The TrA was thinnest during deep exhalation at 90°, followed by 45° and 0°.

CONCLUSION

In healthy young people, deep expiration with 90° hip flexion and 90° knee flexion was the optimal action for activating the LAW, especially the TrA.

The ratio of parasternal intercostal muscle-thickening fraction-to-diaphragm thickening fraction for predicting weaning failure

BACKGROUND

Diaphragm dysfunction is associated with weaning outcomes in mechanical ventilation patients, in the case of diaphragm dysfunction, the accessory respiratory muscles would be recruited. The main purpose of this study is to explore the performance of parasternal intercostal muscle thickening fraction in relation to diaphragmatic thickening fraction ratio (TFic1/TFdi2) for predicting weaning outcomes, and compare its accuracy with D-RSBI in predicting weaning failure.

MATERIALS AND METHODS

We prospectively enrolled consecutive patients from 7/2022-5/2023. We measured TFic, TFdi, and diaphragmatic excursion (DE3) by ultrasound and calculated the TFic/TFdi ratio and diaphragmatic rapid shallow breathing index (D-RSBI4). Receiver-operator characteristic (ROC5) curves evaluated the accuracy of the TFic/TFdi ratio and D-RSBI in predicting weaning failure.

RESULTS

161 were included in the final analysis, 114 patients (70.8%) were successfully weaned from mechanical ventilation. The TFic/TFdi ratio (AUROC = 0.887 (95% CI: 0.821-0.953)) was superior to the D-RSBI (AUROC = 0.875 (95% CI: 0.807-0.944)) for predicting weaning failure.

CONCLUSIONS

The TFic/TFdi ratio predicted weaning failure with high accuracy and outperformed the D-RSBI.

Structured different exercise protocols improve lung function, respiratory muscle strength, and thickness in stroke patients. A randomized controlled trial

BACKGROUND

The effect of core stabilization exercises (CSE) alone, or in combination with neuromuscular electrical stimulation (NMES) and Kinesio taping (KT) on lung function, respiratory muscle strength, and thickness in patients with stroke is not fully known.

OBJECTIVE

To compare the efficacy of NMES and KT applied with CSE on lung functions, respiratory muscle strength, and thickness in patients with stroke.

METHODS

A total of 45 stroke patients were randomly assigned to the core stabilization exercises (CSE) group, CSE+KT group or CSE+NMES group, respectively. All groups received the training protocol for 30-45 minutes, 3 days a week, for 6 weeks. Lung functions were measured using portable spirometry. Respiratory muscle strength was assessed using an analog manometer to measure maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP). Peak cough flow (PCF) was measured with a peak flow meter. Respiratory muscles thickness were determined using ultrasonography.

RESULTS

Except for FVC (%pred) (F=4.432, p=0.018, np2=0.174), FEV1(%pred) (F=3.725, p=0.032, np2=0.151), and MEP (F=3.861, p=0.029, np2=0.155), the overall group by time interaction for rmANOVA showed that there was no statistically significant difference between groups (p>0.05). After post hoc analysis, it was determined that there was no statistically significant difference between the groups in terms of FVC (%pred), FEV1(%pred) and MEP (p>0.025).

CONCLUSIONS

The addition of NMES or KT to core stabilization exercises did not appear to provide additional benefit in improving lung function, respiratory muscle strength, and thickness in stroke patients.

Relationship Between Diaphragm Thickness, Thickening Fraction, Dome Excursion, and Respiratory Pressures in Healthy Subjects: An Ultrasound Study

PURPOSE

Diaphragm ultrasonography is used to identify causes of diaphragm dysfunction. However, its correlation with pulmonary function tests, including maximal inspiratory (MIP) and expiratory pressures (MEP), remains unclear. This study investigated this relationship by measuring diaphragm thickness, thickening fraction (TF), and excursion (DE) using ultrasonography, and their relationship to MIP and MEP. It also examined the influence of age, sex, height, and BMI on these measures.

METHODS

We recruited healthy Japanese volunteers and conducted pulmonary function tests and diaphragm ultrasonography in a seated position. Diaphragm ultrasonography was performed during quiet breathing (QB) and deep breathing (DB) to measure the diaphragm thickness, TF, and DE. A multivariate analysis was conducted, adjusting for age, sex, height, and BMI.

RESULTS

Between March 2022 and January 2023, 109 individuals (56 males) were included from three facilities. The mean (standard deviation) MIP and MEP [cmH2O] were 72.2 (24.6) and 96.9 (35.8), respectively. Thickness [mm] at the end of expiration was 1.7 (0.4), TF [%] was 50.0 (25.9) during QB and 110.7 (44.3) during DB, and DE [cm] was 1.7 (0.6) during QB and 4.4 (1.4) during DB. Multivariate analysis revealed that only DE (DB) had a statistically significant relationship with MIP and MEP (p = 0.021, p = 0.008). Sex, age, and BMI had a statistically significant influence on relationships between DE (DB) and MIP (p = 0.008, 0.048, and < 0.001, respectively).

CONCLUSION

In healthy adults, DE (DB) has a relationship with MIP and MEP. Sex, age, and BMI, but not height, are influencing factors on this relationship.

Perioperative Diaphragm Dysfunction

Diaphragm Dysfunction (DD) is a respiratory disorder with multiple causes. Although both unilateral and bilateral DD could ultimately lead to respiratory failure, the former is more common. Increasing research has recently delved into perioperative diaphragm protection. It has been established that DD promotes atelectasis development by affecting lung and chest wall mechanics. Diaphragm function must be specifically assessed for clinicians to optimally select an anesthetic approach, prepare for adequate monitoring, and implement the perioperative plan. Recent technological advancements, including dynamic MRI, ultrasound, and esophageal manometry, have critically aided disease diagnosis and management. In this context, it is noteworthy that therapeutic approaches for DD vary depending on its etiology and include various interventions, either noninvasive or invasive, aimed at promoting diaphragm recruitment. This review aims to unravel alternative anesthetic and operative strategies that minimize postoperative dysfunction by elucidating the identification of patients at a higher risk of DD and procedures that could cause postoperative DD, facilitating the recognition and avoidance of anesthetic and surgical interventions likely to impair diaphragmatic function.

Ultrasound-guided muscle dissection for lumboperitoneal shunting via lateral abdominal laparotomy

Purpose;Lumboperitoneal shunting (LPS) is a common procedure for treating idiopathic normal pressure hydrocephalus (iNPH), involving two abdominal approaches:anterior abdominal laparotomy and lateral abdominal laparotomy (LAL). While LAL is advantageous in terms of infection risk, it presents challenges such as muscle manipulation and potential deviation from the desired trajectory. This report presents a novel technique that utilizes ultrasound examination of the lateral abdominal wall (UELAW) to visualize the three muscle layers (external oblique, internal oblique, and transversus abdominis) before abdominal manipulation during LAL. Illustrative Case;An 83-year-old iNPH patient underwent LPS with this approach, ensuring precise alignment of the trajectory and successful access to the abdominal cavity. Following the procedure, the patient experienced an improvement in gait disturbance and was discharged without any surgical complications. Conclusion;The use of UELAW during LPS provides clear visualization of the abdominal muscle layers, allowing surgeons to perform the procedure with confidence and accuracy, minimizing the risk of trajectory deviation, and ultimately improving patient outcomes. J. Med. Invest. 71 : 343-345, August, 2024.