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Respiratory Care Nov 2023Diaphragm dysfunction is a highly prevalent phenomenon in patients receiving mechanical ventilation, mainly due to ventilatory over-assistance and the development of...
Diaphragm dysfunction is a highly prevalent phenomenon in patients receiving mechanical ventilation, mainly due to ventilatory over-assistance and the development of diaphragm disuse atrophy. Promoting diaphragm activation whenever possible and facilitating an adequate interaction between the patient and the ventilator is encouraged at the bedside to avoid myotrauma and further lung injury. Eccentric contractions of the diaphragm are defined as muscle activation while muscle fibers are lengthening within the exhalation phase. There is recent evidence that suggests that eccentric activation of the diaphragm is very frequent and may occur during post-inspiratory activity or under different types of patient-ventilator asynchronies, which include ineffective efforts, premature cycling, and reverse triggering. The consequences of this eccentric contraction of the diaphragm may have opposite effects, depending on the level of breathing effort. For instance, during high or excessive effort, eccentric contractions can result in diaphragm dysfunction and injured muscle fibers. Conversely, when eccentric contractions of the diaphragm occur along with low breathing effort, a preserved diaphragm function, better oxygenation, and more aerated lung tissue are observed. Despite this controversial evidence, evaluating the level of breathing effort at the bedside seems crucial and is highly recommended to optimize ventilatory therapy. The impact of eccentric contractions of the diaphragm on the patient's outcome remains to be elucidated.
Topics: Humans; Respiration, Artificial; Diaphragm; Ventilators, Mechanical; Thorax; Lung
PubMed: 37402586
DOI: 10.4187/respcare.11040 -
ACS Nano Nov 2023Preventing unintentional pregnancy is one of the goals of a global public health policy to minimize effects on individuals, families, and society. Various contraceptive... (Review)
Review
Preventing unintentional pregnancy is one of the goals of a global public health policy to minimize effects on individuals, families, and society. Various contraceptive formulations with high effectiveness and acceptance, including intrauterine devices, hormonal patches for females, and condoms and vasectomy for males, have been developed and adopted over the last decades. However, distinct breakthroughs of contraceptive techniques have not yet been achieved, while the associated long-term adverse effects are insurmountable, such as endocrine system disorder along with hormone administration, invasive ligation, and slowly restored fertility after removal of intrauterine devices. Spurred by developments of nanomaterials and bionanotechnologies, advanced contraceptives could be fulfilled via nanomaterial solutions with much safer and more controllable and effective approaches to meet various and specific needs for women and men at different reproductive stages. Nanomedicine techniques have been extended to develop contraceptive methods, such as the targeted drug delivery and controlled release of hormone using nanocarriers for females and physical stimulation assisted vasectomy using functional nanomaterials via photothermal treatment or magnetic hyperthermia for males. Nanomaterial solutions for advanced contraceptives offer significantly improved biosafety, noninvasive administration, and controllable reversibility. This review summarizes the nanomaterial solutions to female and male contraceptives including the working mechanisms, clinical concerns, and their merits and demerits. This work also reviewed the nanomaterials that have been adopted in contraceptive applications. In addition, we further discuss safety considerations and future perspectives of nanomaterials in nanostrategy development for next-generation contraceptives. We expect that nanomaterials would potentially replace conventional materials for contraception in the near future.
Topics: Pregnancy; Female; Male; Humans; Contraception; Vasectomy; Contraceptive Agents; Intrauterine Devices; Hormones
PubMed: 37856253
DOI: 10.1021/acsnano.3c04366 -
JAMA Jul 2023
Topics: Female; Humans; Pregnancy; Intrauterine Devices, Medicated; Levonorgestrel; Risk; Pregnancy, Ectopic; Contraceptive Agents, Hormonal
PubMed: 37490092
DOI: 10.1001/jama.2023.8888 -
Seminars in Pediatric Surgery Feb 2024Diaphragm pacing is a ventilation strategy in respiratory failure. Most of the literature on pacing involves adults with common indications being spinal cord injury and... (Review)
Review
Diaphragm pacing is a ventilation strategy in respiratory failure. Most of the literature on pacing involves adults with common indications being spinal cord injury and amyotrophic lateral sclerosis (ALS). Previous reports in pediatric patients consist of case reports or small series; most describe direct phrenic nerve stimulation for central hypoventilation syndrome. This differs from adult reports that focus most commonly on spinal cord injuries and the rehabilitative nature of diaphragm pacing. This review describes the current state of diaphragm pacing in pediatric patients. Indications, current available technologies, surgical techniques, advantages, and pitfalls/problems are discussed.
Topics: Child; Humans; Amyotrophic Lateral Sclerosis; Diaphragm; Phrenic Nerve; Respiratory Insufficiency
PubMed: 38245992
DOI: 10.1016/j.sempedsurg.2024.151386 -
Journal of Holistic Nursing : Official... Mar 2024Deep diaphragmatic breathing (DDB) involves slow and fully contraction of the diaphragm with expansion of the belly during inhalation, and slow and fully contraction of...
Deep diaphragmatic breathing (DDB) involves slow and fully contraction of the diaphragm with expansion of the belly during inhalation, and slow and fully contraction of the abdominal muscles with reduction of the belly during exhalation. It is the key component of the holistic mind-body exercises commonly used for patients with multimorbidity. The purpose of this study was to re-visit and address the fundamental anatomical and biomechanical consideration of the DDB with the relevant literature. Peer-reviewed publications from last the 15 years were retrieved, reviewed, and analyzed. In this article, we described the updated morphological and anatomical characteristics of the diaphragm. Then, we elucidated in a biomechanical approach how and why the DDB can work on the gastrointestinal, cardiopulmonary, and nervous systems as well as on regulating the intra-abdominopelvic pressure and mind-body interaction to coordinate the diaphragm-pelvic floor-abdominal complex for a variety of physical and physiological activities. Understanding of this updated DDB knowledge may help holistic healthcare professionals including holistic nurses provide better patient education and care management during the DDB or DDB-based mind-body intervention time.
Topics: Humans; Diaphragm; Pelvic Floor; Exercise; Hydrocarbons, Chlorinated
PubMed: 36734111
DOI: 10.1177/08980101221149866 -
Biomolecules Jul 2023The progressive degeneration of the skeletal musculature in Duchenne muscular dystrophy is accompanied by reactive myofibrosis, fat substitution, and chronic... (Review)
Review
The progressive degeneration of the skeletal musculature in Duchenne muscular dystrophy is accompanied by reactive myofibrosis, fat substitution, and chronic inflammation. Fibrotic changes and reduced tissue elasticity correlate with the loss in motor function in this X-chromosomal disorder. Thus, although dystrophinopathies are due to primary abnormalities in the gene causing the almost-complete absence of the cytoskeletal Dp427-M isoform of dystrophin in voluntary muscles, the excessive accumulation of extracellular matrix proteins presents a key histopathological hallmark of muscular dystrophy. Animal model research has been instrumental in the characterization of dystrophic muscles and has contributed to a better understanding of the complex pathogenesis of dystrophinopathies, the discovery of new disease biomarkers, and the testing of novel therapeutic strategies. In this article, we review how mass-spectrometry-based proteomics can be used to study changes in key components of the endomysium, perimysium, and epimysium, such as collagens, proteoglycans, matricellular proteins, and adhesion receptors. The mouse diaphragm displays severe myofibrosis, making it an ideal model system for large-scale surveys of systematic alterations in the matrisome of dystrophic fibers. Novel biomarkers of myofibrosis can now be tested for their appropriateness in the preclinical and clinical setting as diagnostic, pharmacodynamic, prognostic, and/or therapeutic monitoring indicators.
Topics: Animals; Mice; Mice, Inbred mdx; Diaphragm; Proteomics; Muscular Dystrophy, Duchenne; Muscle, Skeletal; Extracellular Matrix; Extracellular Matrix Proteins; Biomarkers
PubMed: 37509144
DOI: 10.3390/biom13071108 -
Biophysical Journal Jun 2024Exchange of material across two membranes, as in the case of synaptic neurotransmitter release from a vesicle, involves the formation and poration of a hemifusion...
Exchange of material across two membranes, as in the case of synaptic neurotransmitter release from a vesicle, involves the formation and poration of a hemifusion diaphragm (HD). The nontrivial geometry of the HD leads to environment-dependent control, regarding the stability and dynamics of the pores required for this kind of exocytosis. This work combines particle simulations, field-based calculations, and phenomenological modeling to explore the factors influencing the stability, dynamics, and possible control mechanisms of pores in HDs. We find that pores preferentially form at the HD rim, and that their stability is sensitive to a number of factors, including the three line tensions, membrane tension, HD size, and the ability of lipids to "flip-flop" across leaflets. Along with a detailed analysis of these factors, we discuss ways that vesicles or cells may use them to open and close pores and thereby quickly and efficiently transport material.
PubMed: 38867448
DOI: 10.1016/j.bpj.2024.06.009 -
Anesthesiology Jan 2024Diaphragm dysfunction and its effects on outcomes of ventilator weaning have been evaluated in mixed critical care populations using diaphragm thickening fraction (the...
BACKGROUND
Diaphragm dysfunction and its effects on outcomes of ventilator weaning have been evaluated in mixed critical care populations using diaphragm thickening fraction (the ratio of the difference between ultrasound diaphragm thickness at end-inspiration and end-expiration to diaphragm thickness at end-expiration) or neuroventilatory efficiency (the ratio of tidal volume and peak electrical activity of the diaphragm). Such data are not available in bilateral-lung transplant recipients. The authors hypothesized that (1) diaphragm dysfunction, as defined by a diaphragm thickening fraction less than 29%, is more likely to occur in difficult weaning; (2) diaphragm thickening fraction and neuroventilatory efficiency predict weaning outcome; and (3) duration of mechanical ventilation before the first spontaneous breathing trial is associated with diaphragm dysfunction.
METHODS
Adult bilateral-lung transplant patients admitted to the intensive care unit were screened at the time of the first spontaneous breathing trial (pressure-support of 5 cm H2O and 0 positive end-expiratory pressure). At the fifth minute, diaphragm thickening fraction and neuroventilatory efficiency were measured during three respiratory cycles. Weaning was classified as simple, difficult, or prolonged (successful extubation at the first spontaneous breathing trial, within three or after three spontaneous breathing trials, respectively).
RESULTS
Forty-four subjects were enrolled. Diaphragm dysfunction occurred in 14 subjects (32%), all of whom had difficult weaning (78% of the subgroup of 18 patients experiencing difficult weaning). Both diaphragm thickening fraction (24 [20 to 29] vs. 39 [35 to 45]%) and neuroventilatory efficiency (34 [26 to 45] vs. 55 [43 to 62] ml/µV) were lower in difficult weaning (both P < 0.001). The areas under the receiver operator curve predicting difficult weaning were 0.88 (95% CI, 0.73 to 0.99) for diaphragm thickening fraction and 0.85 (95% CI, 0.71 to 0.95) for neuroventilatory efficiency. The duration of ventilation demonstrated a linear inverse correlation with both diaphragm thickening fraction and neuroventilatory efficiency.
CONCLUSIONS
Diaphragm dysfunction is common after bilateral-lung transplantation and associated with difficult weaning. In such patients, average values for diaphragm thickening fraction and neuroventilatory efficiency were reduced compared to patients with simple weaning. Both parameters showed similar accuracy for predicting success of ventilator weaning, demonstrating an inverse relationship with duration of ventilation.
Topics: Adult; Humans; Ventilator Weaning; Diaphragm; Respiration, Artificial; Respiration; Lung Transplantation
PubMed: 37552079
DOI: 10.1097/ALN.0000000000004729 -
Current Opinion in Critical Care Feb 2024With mechanical ventilation, positive end-expiratory pressure (PEEP) is applied to improve oxygenation and lung homogeneity. However, PEEP setting has been hypothesized... (Review)
Review
PURPOSE OF REVIEW
With mechanical ventilation, positive end-expiratory pressure (PEEP) is applied to improve oxygenation and lung homogeneity. However, PEEP setting has been hypothesized to contribute to critical illness associated diaphragm dysfunction via several mechanisms. Here, we discuss the impact of PEEP on diaphragm function, activity and geometry.
RECENT FINDINGS
PEEP affects diaphragm geometry: it induces a caudal movement of the diaphragm dome and shortening of the zone of apposition. This results in reduced diaphragm neuromechanical efficiency. After prolonged PEEP application, the zone of apposition adapts by reducing muscle fiber length, so-called longitudinal muscle atrophy. When PEEP is withdrawn, for instance during a spontaneous breathing trial, the shortened diaphragm muscle fibers may over-stretch which may lead to (additional) diaphragm myotrauma. Furthermore, PEEP may either increase or decrease respiratory drive and resulting respiratory effort, probably depending on lung recruitability. Finally, the level of PEEP can also influence diaphragm activity in the expiratory phase, which may be an additional mechanism for diaphragm myotrauma.
SUMMARY
Setting PEEP could play an important role in both lung and diaphragm protective ventilation. Both high and low PEEP levels could potentially introduce or exacerbate diaphragm myotrauma. Today, the impact of PEEP setting on diaphragm structure and function is in its infancy, and clinical implications are largely unknown.
Topics: Humans; Diaphragm; Lung; Positive-Pressure Respiration; Respiration; Respiration, Artificial
PubMed: 38085880
DOI: 10.1097/MCC.0000000000001126 -
Respiratory Medicine Sep 2023Diaphragm ultrasound (DUS) has been extensively used in critically ill patients while data on outpatients with interstitial lung disease (ILD) are limited. We...
BACKGROUND
Diaphragm ultrasound (DUS) has been extensively used in critically ill patients while data on outpatients with interstitial lung disease (ILD) are limited. We hypothesized that diaphragm function, assessed by ultrasound, could be impaired in patients with ILD, considering both Idiopathic Pulmonary Fibrosis (IPF) and Connective Tissue Disease (CTD-ILD), compared to healthy subjects. Moreover, this impairment could impact clinical and functional parameters.
METHODS
All consecutive CTD-ILD and IPF patients followed in our center (March-October 2020) were screened. Diaphragm displacement (DD), inspiratory thickness (Ti), expiratory thickness (Te), thickening fraction (TF), and respiratory functional parameters were collected. The prevalence of diaphragmatic dysfunction (TF <30%) was then recorded.
RESULTS
Eighty-two consecutive patients (41 CTD-ILD, 41 IPF) and 15 age- and sex-matched controls were enrolled. In the overall population, 24 out of 82 (29%) presented diaphragmatic dysfunction. In CTD-ILD, DD and Ti were lower as compared to IPF (p = 0.021 and p = 0.036, respectively); while diaphragmatic dysfunction was more prevalent compared to controls (37% vs 7%, p = 0.043). TF positively correlated to patients' functional parameters in the CTD-ILD group (FVC%pred: p = 0.003; r = 0.45), while not in the IPF group. Diaphragmatic dysfunction was associated with moderate/severe dyspnea in both CTD-ILD and IPF (p = 0.021).
CONCLUSION
The prevalence of diaphragmatic dysfunction was 29% in patients with ILD and was associated with moderate/severe dyspnea. CTD-ILD presented lower DD compared with IPF and a higher prevalence of diaphragmatic dysfunction (TF<30%) compared with controls. TF was associated with lung function only in CTD-ILD patients, suggesting its potential role in the comprehensive patient assessment.
Topics: Humans; Diaphragm; Prevalence; Lung Diseases, Interstitial; Idiopathic Pulmonary Fibrosis; Connective Tissue Diseases; Dyspnea
PubMed: 37271302
DOI: 10.1016/j.rmed.2023.107293