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Biomedical Engineering Online Jan 2023Every year, more than 2.5 million critically ill patients in the ICU are dependent on mechanical ventilation. The positive pressure in the lungs generated by the...
BACKGROUND
Every year, more than 2.5 million critically ill patients in the ICU are dependent on mechanical ventilation. The positive pressure in the lungs generated by the ventilator keeps the diaphragm passive, which can lead to a loss of myofibers within a short time. To prevent ventilator-induced diaphragmatic dysfunction (VIDD), phrenic nerve stimulation may be used.
OBJECTIVE
The goal of this study is to show the feasibility of transesophageal phrenic nerve stimulation (TEPNS). We hypothesize that selective phrenic nerve stimulation can efficiently activate the diaphragm with reduced co-stimulations.
METHODS
An in vitro study in saline solution combined with anatomical findings was performed to investigate relevant stimulation parameters such as inter-electrode spacing, range to target site, or omnidirectional vs. sectioned electrodes. Subsequently, dedicated esophageal electrodes were inserted into a pig and single stimulation pulses were delivered simultaneously with mechanical ventilation. Various stimulation sites and response parameters such as transdiaphragmatic pressure or airway flow were analyzed to establish an appropriate stimulation setting.
RESULTS
Phrenic nerve stimulation with esophageal electrodes has been demonstrated. With a current amplitude of 40 mA, similar response figures of the diaphragm activation as compared to conventional stimulation with needle electrodes at 10mA were observed. Directed electrodes best aligned with the phrenic nerve resulted in up to 16.9 % higher amplitude at the target site in vitro and up to 6 cmH20 higher transdiaphragmatic pressure in vivo as compared to omnidirectional electrodes. The activation efficiency was more sensitive to the stimulation level inside the esophagus than to the inter-electrode spacing. Most effective and selective stimulation was achieved at the level of rib 1 using sectioned electrodes 40 mm apart.
CONCLUSION
Directed transesophageal phrenic nerve stimulation with single stimuli enabled diaphragm activation. In the future, this method might keep the diaphragm active during, and even support, artificial ventilation. Meanwhile, dedicated sectioned electrodes could be integrated into gastric feeding tubes.
Topics: Animals; Swine; Phrenic Nerve; Feasibility Studies; Diaphragm; Respiration, Artificial; Electrodes; Electric Stimulation
PubMed: 36717872
DOI: 10.1186/s12938-023-01071-5 -
Journal of the American College of... Oct 2022In addition to the diaphragm's role as the primary respiratory muscle, it also plays an under-recognized role in cardiac function. It serves as a pump facilitating... (Review)
Review
In addition to the diaphragm's role as the primary respiratory muscle, it also plays an under-recognized role in cardiac function. It serves as a pump facilitating venous and lymph return, modulating left ventricular afterload hemodynamics and pericardial pressures, as well as regulating autonomic tone. Heart failure (HF) is associated with diaphragmatic changes (ie, muscle fiber atrophy and weakness, increased ratio of type I to type II muscle fibers, and altered muscle metaboreflex) that lead to diaphragmatic dysfunction with subsequent symptomatic manifestations of HF. Herein, it is proposed that targeting the diaphragm in patients with HF via inspiratory muscle training or device-based stimulation can provide a novel treatment pathway for HF. Reviewed are several potential mechanisms through which therapies targeting the diaphragm can be beneficial in HF (ie, improving preload reserve, atrial and ventricular synchrony, and metaboreflex activity; reducing pericardial restraint; and restoring diaphragm strength).
Topics: Humans; Diaphragm; Cardiovascular Diseases; Heart Failure; Hemodynamics
PubMed: 36265961
DOI: 10.1016/j.jacc.2022.08.760 -
Radiographics : a Review Publication of... 2020The diaphragm serves as an anatomic border between the abdominal and thoracic cavities. Pathologic conditions traversing the diaphragm are often incompletely described... (Review)
Review
The diaphragm serves as an anatomic border between the abdominal and thoracic cavities. Pathologic conditions traversing the diaphragm are often incompletely described and may be overlooked, resulting in diagnostic delays. Several routes allow abdominal contents or pathologic processes to spread into the thorax, including along normal transphrenic structures, through congenital defects in the diaphragm, through inherent areas of weakness between muscle groups, or by pathways created by tissue destruction, trauma, or iatrogenic injuries. A thorough knowledge of the anatomy of the diaphragm can inform an accurate differential diagnosis. Often, intraperitoneal pathologic conditions crossing the diaphragm may be overlooked if axial imaging is the only approach to this complex region because of the horizontal orientation of much of the diaphragm. Multiplanar capabilities of volumetric CT and MRI provide insight into the pathways where pathologic conditions may traverse this border. Knowledge of these characteristic routes and use of multiplanar imaging are critical for depiction of specific transdiaphragmatic pathologic conditions.RSNA, 2020.
Topics: Abdomen; Diaphragm; Hernia, Diaphragmatic; Humans; Magnetic Resonance Imaging; Thoracic Diseases; Tomography, X-Ray Computed
PubMed: 32706612
DOI: 10.1148/rg.2020200026 -
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 -
Medicina Intensiva Nov 2023This review addresses the phenomenon of "reverse triggering", an asynchrony that occurs in deeply sedated patients or patients in transition from deep to light sedation.... (Review)
Review
This review addresses the phenomenon of "reverse triggering", an asynchrony that occurs in deeply sedated patients or patients in transition from deep to light sedation. Reverse triggering has been reported to occur in 30-90% of all ventilated patients. The underlying pathophysiological mechanisms remain unclear, but "entrainment" is proposed as one of them. Detecting this asynchrony is crucial, and methods such as visual inspection, esophageal pressure, diaphragmatic ultrasound and automated methods have been used. Reverse triggering may have effects on lung and diaphragm function, probably mediated by the level of breathing effort and eccentric activation of the diaphragm. The optimal management of reverse triggering has not been established, but may include the adjustment of ventilatory parameters as well as of sedation level, and in extreme cases, neuromuscular block. It is important to understand the significance of this condition and its detection, but also to conduct dedicated research to improve its clinical management and potential effects in critically ill patients.
Topics: Humans; Respiration, Artificial; Diaphragm; Deep Sedation; Respiratory Mechanics
PubMed: 37867118
DOI: 10.1016/j.medine.2023.10.009 -
BMJ Sexual & Reproductive Health Jul 2023
Topics: Humans; Female; Contraception; Intrauterine Devices
PubMed: 37197913
DOI: 10.1136/bmjsrh-2023-201841 -
The Cochrane Database of Systematic... Feb 2023The copper intrauterine device (Cu-IUD) is a highly effective method of contraception that can also be used for emergency contraception (EC). It is the most effective...
BACKGROUND
The copper intrauterine device (Cu-IUD) is a highly effective method of contraception that can also be used for emergency contraception (EC). It is the most effective form of EC, and is more effective than other existing oral regimens also used for EC. The Cu-IUD provides the unique benefit of providing ongoing contraception after it is inserted for EC; however, uptake of this intervention has been limited. Progestin IUDs are a popular method of long-acting, reversible contraception. If these devices were also found to be effective for EC, they would provide a critical additional option for women. These IUDs could not only provide EC and ongoing contraception, but additional non-contraceptive benefits, including a reduction in menstrual bleeding, cancer prevention, and pain management.
OBJECTIVES
To examine the safety and effectiveness of progestin-containing IUDs for emergency contraception, compared with copper-containing IUDs, or compared with dedicated oral hormonal methods.
SEARCH METHODS
We considered all randomized controlled trials and non-randomized studies of interventions that compared outcomes for individuals seeking a levonorgestrel IUD (LNG-IUD) for EC to a Cu-IUD or dedicated oral EC method. We considered full-text studies, conference abstracts, and unpublished data. We considered studies irrespective of their publication status and language of publication.
SELECTION CRITERIA
We included studies comparing progestin IUDs with copper-containing IUDs, or oral EC methods for emergency contraception.
DATA COLLECTION AND ANALYSIS
We systematically searched nine medical databases, two trials registries, and one gray literature site. We downloaded all titles and abstracts retrieved by electronic searching to a reference management database, and removed duplicates. Three review authors independently screened titles, abstracts, and full-text reports to determine studies eligible for inclusion. We followed standard Cochrane methodology to assess risk of bias, and analyze and interpret the data. We used GRADE methodology to assess the certainty of the evidence.
MAIN RESULTS
We included only one relevant study (711 women); a randomized, controlled, non-inferiority trial comparing LNG-IUDs to Cu-IUDs for EC, with a one-month follow-up. With one study, the evidence was very uncertain for the difference in pregnancy rates, failed insertion rates, expulsion rates, removal rates and the difference in the acceptability of the IUDs. There was also uncertain evidence suggesting the Cu-IUD may slightly increase rates of cramping and the LNG-IUD may slightly increase bleeding and spotting days. AUTHORS' CONCLUSIONS: This review is limited in its ability to provide definitive evidence regarding the LNG-IUD's equivalence, superiority, or inferiority to the Cu-IUD for EC. Only one study was identified in the review, which had possible risks of bias related to randomization and rare outcomes. Additional studies are needed to provide definitive evidence related to the effectiveness of the LNG-IUD for EC.
Topics: Female; Humans; Pregnancy; Contraception, Postcoital; Copper; Intrauterine Devices; Intrauterine Devices, Copper; Progestins; Randomized Controlled Trials as Topic; Steroids
PubMed: 36847591
DOI: 10.1002/14651858.CD013744.pub2 -
Journal of Back and Musculoskeletal... 2022To restore core stability, abdominal drawing-in maneuver (ADIM), abdominal bracing (AB), and dynamic neuromuscular stabilization (DNS) have been employed but outcome...
Comparison of core stabilization techniques on ultrasound imaging of the diaphragm, and core muscle thickness and external abdominal oblique muscle electromyography activity.
BACKGROUND
To restore core stability, abdominal drawing-in maneuver (ADIM), abdominal bracing (AB), and dynamic neuromuscular stabilization (DNS) have been employed but outcome measures varied and one intervention was not superior over another.
OBJECTIVE
The purpose of this study was to compare the differential effects of ADIM, AB, and DNS on diaphragm movement, abdominal muscle thickness difference, and external abdominal oblique (EO) electromyography (EMG) amplitude.
METHODS
Forty-one participants with core instability participated in this study. The subjects performed ADIM, AB, and DNS in random order. A Simi Aktisys and Pressure Biofeedback Unit (PBU) were utilized to measure core stability, an ultrasound was utilized to measure diaphragm movement and measure abdominal muscles thickness and EMG was utilized to measure EO amplitude. Analysis of variance (ANOVA) was conducted at P< 0.05.
RESULTS
Diaphragm descending movement and transverse abdominis (TrA) and internal abdominal oblique (IO) thickness differences were significantly increased in DNS compared to ADIM and AB (P< 0.05). EO amplitude was significantly increased in AB compared to ADIM, and DNS.
CONCLUSIONS
DNS was the best technique to provide balanced co-activation of the diaphragm and TrA with relatively less contraction of EO and subsequently producing motor control for efficient core stabilization.
Topics: Abdominal Muscles; Abdominal Oblique Muscles; Diaphragm; Electromyography; Humans; Muscle Contraction; Ultrasonography
PubMed: 34657872
DOI: 10.3233/BMR-210051 -
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 -
Current Opinion in Obstetrics &... Aug 2022Thoracic endometriosis is a rare disease that can lead to a variety of clinical manifestations. There are currently no guidelines for optimal diagnosis and management of... (Review)
Review
PURPOSE OF REVIEW
Thoracic endometriosis is a rare disease that can lead to a variety of clinical manifestations. There are currently no guidelines for optimal diagnosis and management of the disease. The purpose of this review is to provide an overview of the diagnosis and surgical treatment of thoracic endometriosis.
RECENT FINDINGS
Various imaging modalities, including computed tomography (CT), MRI and ultrasound, have been reported in the detection of thoracic endometriosis. MRI is the most sensitive imaging study and may aid in preoperative planning. Histopathology of a biopsied lesion remains the gold standard for diagnosis. Surgical management of thoracic endometriosis may involve laparoscopy and/or thoracoscopy, and surgical planning should include preparation for single ventilation capability. A multidisciplinary approach involving a gynaecologic surgeon and thoracic surgeon may be considered. Repairing diaphragm defects and pleurodesis are shown to decrease recurrent symptoms.
SUMMARY
Although optimal diagnostic testing remains uncertain, a high clinical suspicion for thoracic endometriosis is critical to ensure prompt diagnosis and treatment in order to prevent recurrent symptoms and progression to more serious sequalae. Minimally invasive surgical techniques are becoming increasingly utilized and allow for thorough evaluation and treatment of thoracic endometriosis.
Topics: Diaphragm; Endometriosis; Female; Humans; Laparoscopy; Minimally Invasive Surgical Procedures; Muscular Diseases
PubMed: 35895962
DOI: 10.1097/GCO.0000000000000792