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.

Diaphragm Ultrasonography: Reference Values and Influencing Factors for Thickness, Thickening Fraction, and Excursion in the Seated Position.

INTRODUCTION: Measurements of diaphragm function by ultrasonography are affected by body position, but reference values in the seated position have not been established for an Asian population. This study aimed to determine reference values for diaphragm thickness, thickening fraction, and dome excursion by ultrasonography and to investigate the effects of sex, height, and body mass index. METHODS: Diaphragm ultrasonography was performed on 109 seated Japanese volunteers with normal respiratory function who were enrolled between March 2022 and January 2023. Thickness, thickening fraction, and excursion were measured. Reference values and the measurement success rate were calculated. Multivariate analysis adjusted for sex, height, and body mass index was performed. RESULTS: The measurement success rate was better for thickness than for excursion. The mean (lower limit of normal) values on the right/left sides were as follows. During quiet breathing, thickness at end expiration(mm) was 1.7 (0.9)/1.6 (0.80), thickening fraction(%) was 50 (0.0)/52 (0.0), and excursion(cm) was 1.7 (0.5)/1.9 (0.5). During deep breathing, the thickening fraction was 111 (24)/107 (22), and the excursion was 4.4 (1.7)/4.1 (2.0). In multivariate analysis, body mass index was positively associated with thickness but not with the thickening fraction. CONCLUSION: The reference values in this study were smaller than those in previous reports from Europe. Considering that thickness is influenced by body mass index, using Western reference values in Asia, where the average body mass index is lower, might not be appropriate. The thickening fraction in deep breathing is unaffected by other items and can be used more universally.

Sphincter of Oddi dysfunction that could not be diagnosed with Rome IV: a case report.

A 30-year-old female patient presented with monthly episodes of severe intermittent upper abdominal pain, especially after consuming fatty meals. Over a period of 5 years, she visited the emergency department 21 times due to the intensity of the pain. Although the pain appeared consistent with biliary pain, both blood and imaging tests showed no abnormalities. Despite not meeting the Rome IV criteria, we suspected sphincter of Oddi dysfunction (SOD). To further investigate, we conducted hepatobiliary scintigraphy (HBS), which revealed a clear delay in bile excretion. With the patient's informed consent, we performed endoscopic sphincterotomy (EST) and as of 10 months later, there have been no recurrences. This case demonstrates an instance of SOD that could not be diagnosed using the Rome IV criteria alone but was successfully identified through HBS. It underscores the possibility of hidden cases of SOD among patients who regularly experience severe epigastric pain, where routine blood or imaging tests may not provide a diagnosis. HBS may be a useful non-invasive test in confirming the presence of previously undiagnosed SOD. As SOD can be easily treated with EST, updating the current diagnostic criteria to include such types of SOD should be considered in the future.

Development of a national point-of-care ultrasound training course for physicians in Japan: A 3-year evaluation.

Purpose: Point-of-care ultrasound (POCUS) allows bedside clinicians to acquire, interpret, and integrate ultrasound images into patient care. Although the availability of POCUS training courses has increased, the educational effectiveness of these courses is unclear. Methods: From 2017 to 2019, we investigated the educational effectiveness of a standardized 2-day hands-on POCUS training course and changes in pre- and post-course exam scores in relationship to participants' (n = 571) clinical rank, years of POCUS experience, and frequency of POCUS use in clinical practice. Results: The mean pre- and post-course examination scores were 67.2 (standard deviation [SD] 12.3) and 79.7 (SD 9.7), respectively. Higher pre-course examination scores were associated with higher clinical rank, more years of POCUS experience, and more frequent POCUS use (p < 0.05). All participants showed significant changes in pre- to post-course exam scores. Though pre-course scores differed by clinical rank, POCUS experience, and frequency of POCUS use, differences in post-course scores according to participant baseline differences were non-significant. Conclusion: A standardized hands-on POCUS training course is effective for improving POCUS knowledge regardless of baseline differences in clinical rank, POCUS experience, or frequency of POCUS use. Future studies shall evaluate changes in POCUS use in clinical practice after POCUS training.