Reliability and validity of ultrasonography in evaluating the thickness, excursion, stiffness, and strain rate of respiratory muscles in non-hospitalized individuals: a systematic review

OBJECTIVE

To summarize the reliability and validity of ultrasonography in evaluating the stiffness, excursion, stiffness, or strain rate of diaphragm, intercostals and abdominal muscles in healthy or non-hospitalized individuals.

LITERATURE SEARCH

PubMed, Embase, SPORTDiscus, CINAHL and Cochrane Library were searched from inception to May 30, 2022.

STUDY SELECTION CRITERIA

Case-control, cross-sectional, and longitudinal studies were included if they investigated the reliability or validity of various ultrasonography technologies (e.g., brightness-mode, motion-mode, shear wave elastography) in measuring the thickness, excursion, stiffness, or strain rate of any respiratory muscles.

DATA SYNTHESIS

Relevant data were summarized based on healthy and different patient populations. The methodological quality by different checklist depending on study design. The quality of evidence of each psychometric property was graded by the Grading of Recommendations, Assessment, Development and Evaluations, respectively.

RESULTS

This review included 24 studies with 787 healthy or non-hospitalized individuals (e.g., lower back pain (LBP), adolescent idiopathic scoliosis (AIS), and chronic obstructive pulmonary disease (COPD)). Both inspiratory (diaphragm and intercostal muscles) and expiratory muscles (abdominal muscles) were investigated. Moderate-quality evidence supported sufficient (intra-class correlation coefficient > 0.7) within-day intra-rater reliability of B-mode ultrasonography in measuring right diaphragmatic thickness among people with LBP, sufficient between-day intra-rater reliability of M-mode ultrasonography in measuring right diaphragmatic excursion in non-hospitalized individuals. The quality of evidence for all other measurement properties in various populations was low or very low. High-quality evidence supported sufficient positive correlations between diaphragm excursion and forced expiratory volume in the first second or forced vital capacity (r >  = 0.3) in healthy individuals.

CONCLUSIONS

Despite the reported sufficient reliability and validity of using ultrasonography to assess the thickness, excursion, stiffness, and strain rate of respiratory muscles in non-hospitalized individuals, further large-scale studies are warranted to improve the quality of evidence regarding using ultrasonography for these measurements in clinical practice. Researchers should establish their own reliability before using various types of ultrasonography to evaluate respiratory muscle functions.

TRIAL REGISTRATION

PROSPERO NO. CRD42022322945.

Methylflavonolamine protects aorta from atherosclerosis in cholesterol-fed rabbits

The effect of methylflavonolamine [4'-methyl-7-(2-hydroxy-3-isopropylamino-propoxy)-flavone hydrochloride, MFA], synthesized recently by the Shanghai Institute of Pharmaceutical Industry, on the development of atherosclerosis was studied in male New Zealand white rabbits fed cholesterol for 10 wk. MFA, 7 mg.kg-1 daily ip, did not significantly alter the serum total cholesterol, HDL, and triglyceride levels, but significantly lowered the aortic cholesterol and calcium contents. Atheromatous lesions covered 53.3 +/- 11.8% of the intimal surface of the aorta in the saline group and 11.3 +/- 2.3% in the MFA group (P < 0.01). We conclude that MFA suppresses cholesterol-induced atherosclerosis.

[Effects of methylflavonolamine hydrochloride on contractility of isolated rabbit ileum]

Methylflavonolamine hydrochloride (MFA), verapamil (Ver), and trifluoperazine (Tri) inhibited the contractions induced by submaximal concentrations of acetylcholine (ACh) and serotonin (5-HT). IC50 values (mumol.L-1) were 33.2 +/- 0.7, 0.276 +/- 0.018, 3.83 +/- 0.23, and 15.31 +/- 0.10, 0.233 +/- 0.017, 2.33 +/- 0.20, respectively. MFA, Ver, and Tri inhibited the contractions induced by CaCl2 and pD'2 values were 4.3 +/- 0.3, 6.23 +/- 0.22, 4.99 +/- 0.24, respectively. MFA 3 mumol.L-1, Ver 0.03 mumol.L-1, and Tri 3 mumol.L-1 inhibited the contractions induced by ACh in Ca(2+)-free medium, while MFA 60 mumol.L-1, Tri 30 mumol.L-1, but not Ver 0.6 mumol.L-1, had pronounced inhibitions on extracellular calcium-dependent contractions induced by ACh. These results suggest that MFA has a calcium antagonistic effect and that MFA is similar to Tri, but not Ver, in mechanism.

[Anti-arrhythmia and anti-lipid peroxidation effects of methylflavonolamine]

Effects of methylflavonolamine (MFA) on arrhythmias induced by myocardial reperfusion were studied with rat hearts in situ and in vitro. In pentobarbital-anesthetized rats, MFA (20 mg.kg-1, i.v.) pretreatment reduced the incidence of reperfusion-induced ventricular fibrillation after left descending coronary artery ligation (15 min) and reperfusion (3 min) (28.6% vs 85.7% in control, P less than 0.05). Malondialdehyde (MDA) production (85 +/- 9 nmol/g wet wt) was inhibited in myocardium from the reperfused area in comparison with control (133 +/- 15 nmol/g wet wt). In isolated rat hearts with local ischemia (15 min) and reperfusion (1 min), MFA 5 mumol.L-1 (perfused 10 min prior to coronary artery ligation) prevented reperfusion-induced arrhythmias (0% vs 85.7% in control, P less than 0.01). In myocardium from the reperfused area, superoxide dismutase (SOD) and catalase (Cat) activity was increased and xanthine oxidase (XOD) activity, MDA production and nonesterified fatty acids (NEFA) contents were decreased. The results show that MFA prevents reperfusion-induced arrhythmia by inhibiting lipid peroxidation and regulating the metabolism of NEFA.

Methylflavonolamine hydrochloride inhibits contractions induced by noradrenaline, calcium and potassium in rabbit isolated aortic strips

1. The effects of methylflavonolamine hydrochloride (4'-methyl-7-(2-hydroxy-3-isopropylamino-propoxy)-flavone hydrochloride, MFA) were investigated and compared with verapamil and papaverine on rabbit isolated aortic strips, which were contracted by noradrenaline, calcium and potassium. 2. Pre-incubation for 25 min with either MFA (0.03 to 0.2 mM) or papaverine (0.03 to 0.2 mM) induced non-parallel and concentration-dependent rightward displacements of the curves to noradrenaline (0.00001 to 0.1 mM) with the maximal response depressed. The calculated pD2' values (mean +/- s.d.) were 3.89 +/- 0.15 for MFA and 3.93 +/- 0.05 for papaverine, respectively. Verapamil (0.03 to 0.2 mM) inhibited the contraction induced by noradrenaline in a competitive manner with a pA2 value of 5.91 +/- 0.83. 3. In depolarized aortic strips of the rabbit, prior exposure to MFA (0.03 to 0.3 mM) and papaverine (0.03 to 0.2 mM) shifted the cumulative curves to Ca2+ (0.003 to 100 mM) parallel to the right with the maximal responses depressed, pD'2 values being 3.88 +/- 0.05 and 3.89 +/- 0.13, respectively. Verapamil produced comparable inhibition of the contraction at much lower concentrations (30 to 300 nM). 4. MFA (0.03 and 0.1 mM) inhibited the contraction elicited by graded depolarization at a constant Ca2+ concentration with a pD'2 value of 4.09 +/- 0.07. 5. The present results show that MFA has some actions consistent with a calcium antagonist. It resembles papaverine more closely than verapamil.