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Current Opinion in Critical Care Feb 2020To review the clinical problem of diaphragm function in critically ill patients and describes recent advances in bedside monitoring of diaphragm function. (Review)
Review
PURPOSE OF REVIEW
To review the clinical problem of diaphragm function in critically ill patients and describes recent advances in bedside monitoring of diaphragm function.
RECENT FINDINGS
Diaphragm weakness, a consequence of diaphragm dysfunction and atrophy, is common in the ICU and associated with serious clinical consequences. The use of ultrasound to assess diaphragm structure (thickness, thickening) and mobility (caudal displacement) appears to be feasible and reproducible, but no large-scale 'real-life' study is available. Diaphragm ultrasound can also be used to evaluate diaphragm muscle stiffness by means of shear-wave elastography and strain by means of speckle tracking, both of which are correlated with diaphragm function in healthy. Electrical activity of the diaphragm is correlated with diaphragm function during brief airway occlusion, but the repeatability of these measurements exhibits high within-subject variability.
SUMMARY
Mechanical ventilation is involved in the pathogenesis of diaphragm dysfunction, which is associated with severe adverse events. Although ultrasound and diaphragm electrical activity could facilitate monitoring of diaphragm function to deliver diaphragm-protective ventilation, no guidelines concerning the use of these modalities have yet been published. The weaning process, assessment of patient-ventilator synchrony and evaluation of diaphragm function may be the most clinically relevant indications for these techniques.
Topics: Critical Illness; Diaphragm; Humans; Intensive Care Units; Respiration, Artificial; Ultrasonography
PubMed: 31876624
DOI: 10.1097/MCC.0000000000000682 -
Advances in Respiratory Medicine 2017The diaphragm is the primary muscle involved in active inspiration and serves also as an important anatomical landmark that separates the thoracic and abdominal cavity.... (Review)
Review
The diaphragm is the primary muscle involved in active inspiration and serves also as an important anatomical landmark that separates the thoracic and abdominal cavity. However, the diaphragm muscle like other structures and organs in the human body has more than one function, and displays many anatomic links throughout the body, thereby forming a 'network of breathing'. Besides respiratory function, it is important for postural control as it stabilises the lumbar spine during loading tasks. It also plays a vital role in the vascular and lymphatic systems, as well as, is greatly involved in gastroesophageal functions such as swallowing, vomiting, and contributing to the gastroesophageal reflux barrier. In this paper we set out in detail the anatomy and embryology of the diaphragm and attempt to show it serves as both: an important exchange point of information, originating in different areas of the body, and a source of information in itself. The study also discusses all of its functions related to breathing.
Topics: Diaphragm; Esophagogastric Junction; Humans; Posture; Respiratory Mechanics; Work of Breathing
PubMed: 28871591
DOI: 10.5603/ARM.2017.0037 -
BMC Pulmonary Medicine Mar 2021Diaphragm muscle dysfunction is increasingly recognized as an important element of several diseases including neuromuscular disease, chronic obstructive pulmonary... (Review)
Review
Diaphragm muscle dysfunction is increasingly recognized as an important element of several diseases including neuromuscular disease, chronic obstructive pulmonary disease and diaphragm dysfunction in critically ill patients. Functional evaluation of the diaphragm is challenging. Use of volitional maneuvers to test the diaphragm can be limited by patient effort. Non-volitional tests such as those using neuromuscular stimulation are technically complex, since the muscle itself is relatively inaccessible. As such, there is a growing interest in using imaging techniques to characterize diaphragm muscle dysfunction. Selecting the appropriate imaging technique for a given clinical scenario is a critical step in the evaluation of patients suspected of having diaphragm dysfunction. In this review, we aim to present a detailed analysis of evidence for the use of ultrasound and non-ultrasound imaging techniques in the assessment of diaphragm dysfunction. We highlight the utility of the qualitative information gathered by ultrasound imaging as a means to assess integrity, excursion, thickness, and thickening of the diaphragm. In contrast, quantitative ultrasound analysis of the diaphragm is marred by inherent limitations of this technique, and we provide a detailed examination of these limitations. We evaluate non-ultrasound imaging modalities that apply static techniques (chest radiograph, computerized tomography and magnetic resonance imaging), used to assess muscle position, shape and dimension. We also evaluate non-ultrasound imaging modalities that apply dynamic imaging (fluoroscopy and dynamic magnetic resonance imaging) to assess diaphragm motion. Finally, we critically review the application of each of these techniques in the clinical setting when diaphragm dysfunction is suspected.
Topics: Critical Illness; Diaphragm; Fluoroscopy; Humans; Magnetic Resonance Imaging; Radiography, Thoracic; Tomography, X-Ray Computed; Ultrasonography
PubMed: 33722215
DOI: 10.1186/s12890-021-01441-6 -
Pulmonary Medicine 2019Chronic Obstructive Pulmonary Disease (COPD) impairs the function of the diaphragm by placing it at a mechanical disadvantage, shortening its operating length and... (Comparative Study)
Comparative Study Randomized Controlled Trial
Comparison of Diaphragmatic Stretch Technique and Manual Diaphragm Release Technique on Diaphragmatic Excursion in Chronic Obstructive Pulmonary Disease: A Randomized Crossover Trial.
BACKGROUND
Chronic Obstructive Pulmonary Disease (COPD) impairs the function of the diaphragm by placing it at a mechanical disadvantage, shortening its operating length and changing the mechanical linkage between its various parts. This makes the diaphragm's contraction less effective in raising and expanding the lower rib cage, thereby increasing the work of breathing and reducing the functional capacity.
AIM OF THE STUDY
To compare the effects of diaphragmatic stretch and manual diaphragm release technique on diaphragmatic excursion in patients with COPD.
MATERIALS AND METHODS
This randomised crossover trial included 20 clinically stable patients with mild and moderate COPD classified according to the GOLD criteria. The patients were allocated to group A or group B by block randomization done by primary investigator. The information about the technique was concealed in a sealed opaque envelope and revealed to the patients only after allocation of groups. After taking the demographic data and baseline values of the outcome measures (diaphragm mobility by ultrasonography performed by an experienced radiologist and chest expansion by inch tape performed by the therapist), group A subjects underwent the diaphragmatic stretch technique and the group B subjects underwent the manual diaphragm release technique. Both the interventions were performed in 2 sets of 10 deep breaths with 1-minute interval between the sets. The two outcome variables were recorded immediately after the intervention. A wash-out period of 3 hours was maintained to neutralize the effect of given intervention. Later the patients of group A and group B were crossed over to the other group.
RESULTS
In the diaphragmatic stretch technique, there was a statistically significant improvement in the diaphragmatic excursion before and after the treatment. On the right side, p=0.00 and p=0.003 in the midclavicular line and midaxillary line. On the left side, p=0.004 and p=0.312 in the midclavicular and midaxillary line. In manual diaphragm release technique, there was a statistically significant improvement before and after the treatment. On the right side, p=0.000 and p=0.000 in the midclavicular line and midaxillary line. On the left side, p=0.002 and p=0.000 in the midclavicular line and midaxillary line. There was no statistically significant difference in diaphragmatic excursion in the comparison of the postintervention values of both techniques.
CONCLUSION
The diaphragmatic stretch technique and manual diaphragm release technique can be safely recommended for patients with clinically stable COPD to improve diaphragmatic excursion.
Topics: Aged; Cross-Over Studies; Diaphragm; Female; Humans; Male; Middle Aged; Movement; Musculoskeletal Manipulations; Pulmonary Disease, Chronic Obstructive; Ultrasonography; Work of Breathing
PubMed: 30719351
DOI: 10.1155/2019/6364376 -
The New England Journal of Medicine Mar 2008The combination of complete diaphragm inactivity and mechanical ventilation (for more than 18 hours) elicits disuse atrophy of myofibers in animals. We hypothesized that...
BACKGROUND
The combination of complete diaphragm inactivity and mechanical ventilation (for more than 18 hours) elicits disuse atrophy of myofibers in animals. We hypothesized that the same may also occur in the human diaphragm.
METHODS
We obtained biopsy specimens from the costal diaphragms of 14 brain-dead organ donors before organ harvest (case subjects) and compared them with intraoperative biopsy specimens from the diaphragms of 8 patients who were undergoing surgery for either benign lesions or localized lung cancer (control subjects). Case subjects had diaphragmatic inactivity and underwent mechanical ventilation for 18 to 69 hours; among control subjects diaphragmatic inactivity and mechanical ventilation were limited to 2 to 3 hours. We carried out histologic, biochemical, and gene-expression studies on these specimens.
RESULTS
As compared with diaphragm-biopsy specimens from controls, specimens from case subjects showed decreased cross-sectional areas of slow-twitch and fast-twitch fibers of 57% (P=0.001) and 53% (P=0.01), respectively, decreased glutathione concentration of 23% (P=0.01), increased active caspase-3 expression of 100% (P=0.05), a 200% higher ratio of atrogin-1 messenger RNA (mRNA) transcripts to MBD4 (a housekeeping gene) (P=0.002), and a 590% higher ratio of MuRF-1 mRNA transcripts to MBD4 (P=0.001).
CONCLUSIONS
The combination of 18 to 69 hours of complete diaphragmatic inactivity and mechanical ventilation results in marked atrophy of human diaphragm myofibers. These findings are consistent with increased diaphragmatic proteolysis during inactivity.
Topics: Adolescent; Adult; Aged; Biopsy; Brain Death; Case-Control Studies; Diaphragm; Female; Gene Expression; Humans; Male; Middle Aged; Muscle Fibers, Skeletal; Muscle Proteins; Muscular Atrophy; Pectoralis Muscles; RNA, Messenger; Respiration, Artificial; SKP Cullin F-Box Protein Ligases; Tissue Donors; Tripartite Motif Proteins; Ubiquitin-Protein Ligases
PubMed: 18367735
DOI: 10.1056/NEJMoa070447 -
Journal of Neuromuscular Diseases 2018Respiratory muscles are classically involved in neuromuscular disorders, leading to a restrictive respiratory pattern. The diaphragm is the main respiratory muscle... (Review)
Review
Respiratory muscles are classically involved in neuromuscular disorders, leading to a restrictive respiratory pattern. The diaphragm is the main respiratory muscle involved during inspiration. Ultrasound imaging is a noninvasive, radiation-free, accurate and safe technique allowing assessment of diaphragm anatomy and function. The authors review the pathophysiology of diaphragm in neuromuscular disorders, the methodology and indications of diaphragm ultrasound imaging as well as possible pitfalls in the interpretation of results.
Topics: Diaphragm; Humans; Neuromuscular Diseases; Ultrasonography
PubMed: 29278898
DOI: 10.3233/JND-170276 -
The British Journal of Radiology Jul 2018The diaphragm is an unique skeletal muscle separating the thoracic and abdominal cavities with a primary function of enabling respiration. When abnormal, whether by... (Review)
Review
The diaphragm is an unique skeletal muscle separating the thoracic and abdominal cavities with a primary function of enabling respiration. When abnormal, whether by congenital or acquired means, the consequences for patients can be severe. Abnormalities that affect the diaphragm are often first detected on chest radiographs as an alteration in position or shape. Cross-sectional imaging studies, primarily CT and occasionally MRI, can depict structural defects, intrinsic and adjacent pathology in greater detail. Fluoroscopy is the primary radiologic means of evaluating diaphragmatic motion, though MRI and ultrasound also are capable of this function. This review provides an update on diaphragm embryogenesis and discusses current imaging of various abnormalities, including the emerging role of three-dimensional printing in planning surgical repair of diaphragmatic derangements.
Topics: Diaphragm; Humans
PubMed: 29485899
DOI: 10.1259/bjr.20170600 -
American Family Physician Jan 2004When used with a spermicide, the diaphragm can be a more effective barrier contraceptive than the male condom. The diaphragm allows female-controlled contraception. It... (Review)
Review
When used with a spermicide, the diaphragm can be a more effective barrier contraceptive than the male condom. The diaphragm allows female-controlled contraception. It also provides moderate protection against sexually transmitted diseases and is less expensive than some contraceptive methods (e.g., oral contraceptive pills). However, diaphragm use is associated with more frequent urinary tract infections. Contraindications to use of a diaphragm include known hypersensitivity to latex (unless the wide seal rim diaphragm is used) or a history of toxic shock syndrome. A diaphragm is fitted properly if the posterior rim rests comfortably in the posterior fornix, the anterior rim rests snugly behind the pubic bone, and the cervix can be felt through the dome of the device. The diaphragm should not be left in the vagina for longer than 24 hours. When the diaphragm is the chosen method of contraception, patient education is key to compliance and effectiveness. An extended visit with the physician or a nurse may be required for a woman to learn proper insertion, removal, and care of the diaphragm.
Topics: Anthropometry; Cervix Uteri; Contraception; Contraceptive Devices, Female; Contraindications; Equipment Design; Female; Humans; Latex Hypersensitivity; Palpation; Patient Compliance; Patient Education as Topic; Shock, Septic; Spermatocidal Agents; Time Factors; Urinary Tract Infections; Vagina
PubMed: 14727824
DOI: No ID Found -
Muscle & Nerve Aug 2022Diaphragm ultrasound is increasingly used in the diagnosis of diaphragm dysfunction and to guide respiratory management in patients with neuromuscular disorders and...
INTRODUCTION/AIMS
Diaphragm ultrasound is increasingly used in the diagnosis of diaphragm dysfunction and to guide respiratory management in patients with neuromuscular disorders and those who are critically ill. However, the association between diaphragm ultrasound variables and demographic factors like age, sex, and body mass index (BMI) are understudied. Such relationships are important for correct interpretation of normative values and comparison with selected patients groups. The aim of this study was to determine the associations between diaphragm ultrasound variables and subject characteristics.
METHODS
B-mode ultrasound was used to image the diaphragm at the zone of apposition in 83 healthy subjects. Diaphragm thickness at resting end-expiration (T ), diaphragm thickness at maximal end-inspiration (T ), diaphragm thickening ratio (T /T ), and diaphragm echogenicity were measured. Multivariate linear regression was used to explore the associations between diaphragm ultrasound variables and subject characteristics.
RESULTS
T , T , and thickening ratio do not change with age whereas diaphragm echogenicity increases with age. The thickening ratio had a weak negative association with BMI, while T was positively associated with BMI. Men had a larger T and T than women (T 1.6 ± 0.5 and 1.4 ± 0.3 mm; p = .011, T 3.8 ± 1.0 and 3.2 ± 0.9 mm; p = .004), but similar thickening ratios.
DISCUSSION
Diaphragm thickness, thickening, and echogenicity measured with ultrasound are associated with factors such as age, BMI, and sex. Therefore, subject characteristics should be considered when interpreting diaphragm ultrasound measurements. In the absence of normative values, matched control groups are a prerequisite for research and in clinical practice.
Topics: Age Factors; Body Mass Index; Diaphragm; Female; Healthy Volunteers; Humans; Male; Respiration; Sex Factors; Ultrasonography
PubMed: 35583147
DOI: 10.1002/mus.27639 -
Comprehensive Physiology Mar 2019Symmorphosis is a concept of economy of biological design, whereby structural properties are matched to functional demands. According to symmorphosis, biological... (Review)
Review
Symmorphosis is a concept of economy of biological design, whereby structural properties are matched to functional demands. According to symmorphosis, biological structures are never over designed to exceed functional demands. Based on this concept, the evolution of the diaphragm muscle (DIAm) in mammals is a tale of two structures, a membrane that separates and partitions the primitive coelomic cavity into separate abdominal and thoracic cavities and a muscle that serves as a pump to generate intra-abdominal (P ) and intrathoracic (P ) pressures. The DIAm partition evolved in reptiles from folds of the pleural and peritoneal membranes that was driven by the biological advantage of separating organs in the larger coelomic cavity into separate thoracic and abdominal cavities, especially with the evolution of aspiration breathing. The DIAm pump evolved from the advantage afforded by more effective generation of both a negative P for ventilation of the lungs and a positive P for venous return of blood to the heart and expulsive behaviors such as airway clearance, defecation, micturition, and child birth. © 2019 American Physiological Society. Compr Physiol 9:715-766, 2019.
Topics: Animals; Biological Evolution; Diaphragm; Humans; Nervous System Physiological Phenomena; Pressure
PubMed: 30873594
DOI: 10.1002/cphy.c180012