Influence of sex on diaphragm thickness using a method for determining intima media thickness in healthy young adults

Background: To clarify the differences in diaphragm thickness between male and female participants in healthy young adults using ultrasonography and to investigate the relationship between diaphragm thickness and respiratory pressure.Methods: Twenty-nine healthy individuals (16 females and 13 males) participated in the study. Diaphragm thickness was measured at total lung capacity (TLC) and at functional residual capacity (FRC) in each participant. We measured the diaphragm thickness using a method for mean intima media thickness. Moreover, change ratio of diaphragm thickness was calculated with the diaphragm thickness at TLC and FRC.Results: Mean diaphragm thicknesses at FRC in males were significantly narrower than those in females (p<0.001). The change ratio of diaphragm thickness was significantly augmented in males compared with that in females (p<0.001). There was a significant positive correlation between the change ratio of diaphragm thickness and respiratory muscle strength in males but not in females.Conclusions: The change ratio might be an alternative to evaluate respiratory muscle strength in young adult males. The diaphragm thickness values and the change ratio of diaphragm thickness in healthy young adults, evaluated by B-mode sonography, were varied based on sex.

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.

The Main Role of Diaphragm Muscle as a Mechanism of Hypopressive Abdominal Gymnastics to Improve Non-Specific Chronic Low Back Pain: A Randomized Controlled Trial

Background: Chronic low back pain (LBP) has been stated as one of the main health concerns in the XXI century due to its high incidence. Objective: The objective of this study was to determine the effects of an 8-week program of hypopressive abdominal gymnastics (HAG) on inspiratory muscle strength, diaphragm thickness, disability and pain in patients suffering from non-specific chronic LBP. Methods: A total of 40 patients with chronic LBP were randomly divided into two groups. The experimental group carried out an 8-week supervised program of HAG (two sessions/week), whereas the control group did not receive any treatment. Outcomes were measured before and after the intervention, comprising diaphragm thickness during relaxed respiratory activity, maximal inspiratory pressure (PImax), pain intensity (NRS), pressure pain threshold and responses to four questionnaires: Physical Activity Questionnaire (PAQ), Roland–Morris Disability Questionnaire (RMQ), Central Sensitization Inventory (CSI) and Tampa Scale of Kinesiophobia-11 Items (TSK-11). Results: Statistically significant differences (p < 0.05) were observed for greater thickness of the left and right hemi-diaphragms at inspiration, as well as higher PImax and decreased NRS, CSI and RMQ scores in the intervention group. After treatment, the increases in the thickness of the left and right hemi-diaphragms at inspiration and PImax, as well as the decrease in the NRS and RMQ scores, were only predicted by the proposed intervention (R2 = 0.118–0.552). Conclusions: An 8-week HAG intervention seemed to show beneficial effects and predicted an increase in diaphragm thickness and strength during inspiration, as well as a reduction in pain intensity, central sensitization and disability, in patients suffering from chronic non-specific LBP with respect to non-intervention.

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

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

Phrenic nerve stimulation prevents diaphragm atrophy in patients with respiratory failure on mechanical ventilation

Background Diaphragm atrophy and dysfunction is a major problem among critically ill patients on mechanical ventilation. Ventilator-induced diaphragmatic dysfunction is thought to play a major role, resulting in a failure of weaning. Stimulation of the phrenic nerves and resulting diaphragm contraction could potentially prevent or treat this atrophy. The subject of this study is to determine the effectiveness of diaphragm stimulation in preventing atrophy by measuring changes in its thickness. Methods A total of 12 patients in the intervention group and 10 patients in the control group were enrolled. Diaphragm thickness was measured by ultrasound in both groups at the beginning of study enrollment (hour 0), after 24 hours, and at study completion (hour 48). The obtained data were then statistically analyzed and both groups were compared. Results The results showed that the baseline diaphragm thickness in the interventional group was (1.98 ± 0.52) mm and after 48 hours of phrenic nerve stimulation increased to (2.20 ± 0.45) mm (p=0.001). The baseline diaphragm thickness of (2.00 ± 0.33) mm decreased in the control group after 48 hours of mechanical ventilation to (1.72 ± 0.20) mm (p<0.001). Conclusions Our study demonstrates that induced contraction of the diaphragm by pacing the phrenic nerve not only reduces the rate of its atrophy during mechanical ventilation but also leads to an increase in its thickness – the main determinant of the muscle strength required for spontaneous ventilation and successful ventilator weaning. Trial registration: The study was registered with ClinicalTrials.gov (18/06/2018, NCT03559933, https://clinicaltrials.gov/ct2/show/NCT03559933).

Respiratory burden in obese and young asthmatics: a study of diaphragmatic kinetics

Objective: The aim of this study was to assess the diaphragm kinetics, respiratory function, and serum dosage of leptin and inflammatory cytokines (IL-6 and TNF-a) in three clinical groups: obese, asthmatic, and healthy. Methods: This is a clinical exploratory study performed on 73 youths (12-24 years of age, 42.5% male) allocated into three groups: obesity (OG, n=33), body mass index (BMIz-score) = +2, asthmatic (AG, n=26) controlled mild asthmatics, classified by GINA, and Healthy Control Group (CG, n=14). The participants were subjected to diaphragmatic ultrasound, spirometry, maximal respiratory pressure, serum leptin levels, and IL-6 and TNF-a whole blood cell culture levels. Results: Diaphragm thickness was higher in OG in comparison to AG and CG (2.0±0.4 vs 1.7±0.5 and 1.6±0.2, both with p<0.05). Maximal voluntary ventilation (MVV) was significantly lower in OG and AG in relation to the CG (82.8±21.4 and 72.5±21.2 vs 102.8±27.3, both with p<0.05). OG has the highest leptin rate among the groups (with the other two groups had p<0.05). All groups had similar TNF-a and IL-6 levels. Conclusion: The muscular hypertrophy found in the diaphragm of the obese individuals can be justified by the increase in respiratory work imposed by the chronic condition of the disease. Such increase in thickness did not occur in controlled mild asthmatics. The IL-6 and TNF-a markers detected no evidence of muscle inflammation, even though leptin was expected to be altered in obese individuals. Both obese and asthmatic patients had lower pulmonary resistance than the healthy ones.

Effect of Backstay on Tall Structure with Podium Structure

In a multi-functional tall building, generally the building has a more extensive plan area and higher lateral resistance at the lower story level than the above story levels. So, the scope of this study is to understand the realistic behavior of such structures under lateral loads considering the backstay effect as per IS: 16700(2017). A Sensitivity Analysis was performed as per IS: 16700(2017) provisions by considering the stiffness parameters given in code to understand the changes in the shear force distribution among structural elements when the tower and Podium are modeled together. The changes in the force distribution are compared with the structure without the backstay effect. At the podium-tower interface level, the amount of backstay forces developed is also presented in this paper, along with the impact on backstay forces with changes in the lateral resistances by changing floor diaphragm thickness and by changing the podium area.

Concurrent Validity and Reliability of Manual Versus Specific Device Transcostal Measurements for Breathing Diaphragm Thickness by Ultrasonography in Lumbopelvic Pain Athletes

The use of rehabilitative ultrasound imaging (RUSI) to evaluate diaphragm thickness during breathing in athletes who suffer from non-specific lumbopelvic pain presents some measurement errors. The purpose of this study was to evaluate intra- and inter-sessions, intra- and inter-rater reliabilities, and concurrent validity of diaphragm thickness measurements during breathing using transcostal RUSI with a novel thoracic orthotic device that was used to fix the US probe versus those measurements obtained using manual fixation. A total of 37 athletes with non-specific lumbopelvic pain were recruited. Intra- (same examiner) and inter-rater (two examiners) and intra- (same day) and inter-session (alternate days) reliabilities were analyzed. All measurements were obtained after manual probe fixation and after positioning the thoracic orthotic device to fix the US probe in order to correctly correlate both measurement methods. Both left and right hemi-diaphragm thickness measurements were performed by transcostal RUSI at maximum inspiration, expiration, and the difference between the two parameters during relaxed breathing. Intra-class correlation coefficients (ICC), standard errors of measurement (SEM), minimum detectable changes (MCD), systematic errors, and correlations (r) were assessed. Orthotic device probe fixation showed excellent reliability (ICC = 0.852–0.996, SEM = 0.0002–0.054, and MDC = 0.002–0.072), and most measurements did not show significant systematic errors (p > 0.05). Despite manual probe fixation with a reliability ranging from good to excellent (ICC = 0.714–0.997, SEM = 0.003–0.023, and MDC = 0.008–0.064 cm), several significant systematic measurement errors (p < 0.05) were found. Most significant correlations between both orthotic device and manual probe fixation methods were moderate (r = 0.486–0.718; p < 0.05). Bland–Altman plots indicated adequate agreement between both measurement methods according to the agreement limits. The proposed novel thoracic orthotic device may allow ultrasound probe fixation to provide valid and reliable transcostal RUSI measurements of diaphragmatic thickness during relaxed breathing thus reducing some measurement errors and avoiding systematic measurement errors. It may be advisable to measure diaphragm thickness and facilitate visual biofeedback with respect to diaphragm re-education during normal breathing in athletes with non-specific lumbopelvic pain.