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Journal of Atrial Fibrillation Dec 2015Atrial fibrillation ablation has emerged as an effective tool in the management of symptomatic atrial fibrillation. Currently, the electrophysiologists are striving to... (Review)
Review
Atrial fibrillation ablation has emerged as an effective tool in the management of symptomatic atrial fibrillation. Currently, the electrophysiologists are striving to maximize the success while minimizing complications. Phrenic nerve injury (PNI) is one of the concerning complications, especially in cases of cryoballoon ablation. Due to anatomical proximity to atrial tissue, phrenic nerve is particularly susceptible to injury. With evolving monitoring techniques it is now possible to minimize the likelihood of a permanent PNI. However, the challenge remains to detect PNI at the earliest and to avoid further damage to the nerve. In this review, we discuss pertinent anatomical principles, techniques to avoid PNI and management in cases where PNI is encountered.
PubMed: 27957229
DOI: 10.4022/jafib.1314 -
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 -
Acta Neurologica Belgica Feb 2021Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder affecting the upper and lower motor neurons causing progressive weakness. It eventually involves the...
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder affecting the upper and lower motor neurons causing progressive weakness. It eventually involves the diaphragm which leads to respiratory paralysis and subsequently death. Phrenic nerve (PN) conduction studies and diaphragm ultrasound has been studied and correlated with pulmonary function tests in ALS patients. However, PN ultrasonography has not been employed in ALS. This study aims to sonographically evaluate the morphologic appearance of the PN of ALS patients. Thirty-eight ALS patients and 28 normal controls referred to the neurophysiology laboratory of two institutions were retrospectively included in the study. Baseline demographic and clinical variables such as disease duration, ALS Functional Rating Scale-Revised score, and ALS region of onset were collected. Ultrasound was used to evaluate the PN cross-sectional area (CSA) of ALS and control subjects. The mean PN CSA of ALS patients were 1.08 ± 0.39 mm on the right and 1.02 ± 0.34 mm on the left. The PN CSA of ALS patients were significantly decreased compared to controls (p value < 0.00001). The PN CSA of ALS patients was not correlated to any of the demographic and clinical parameters tested. This study demonstrates that ALS patients have a smaller PN size compared to controls using ultrasonography.
Topics: Adult; Aged; Aged, 80 and over; Amyotrophic Lateral Sclerosis; Female; Humans; Male; Middle Aged; Neural Conduction; Phrenic Nerve; Retrospective Studies; Ultrasonography, Interventional; Young Adult
PubMed: 33136272
DOI: 10.1007/s13760-020-01531-y -
International Journal of Chronic... 2022This review summarizes the characteristics, assessment methods, and targeted rehabilitation therapies of diaphragm dysfunction in patients with chronic obstructive... (Review)
Review
PURPOSE
This review summarizes the characteristics, assessment methods, and targeted rehabilitation therapies of diaphragm dysfunction in patients with chronic obstructive pulmonary disease (COPD).
METHODS
Extensive literature was searched in PubMed, the Cochrane Library, Web of Science, Chinese National Knowledge Infrastructure Database, Wanfang, and SinoMed.
RESULTS
Under the influence of oxidative stress, inflammation, and other factors, the diaphragm function of patients with COPD changes in mobility, muscle strength, thickness, and thickening. In patients with COPD, diaphragm mobility can be assessed using ultrasound, X-ray fluoroscopy, and magnetic resonance imaging. Diaphragmatic strength can be measured by transdiaphragmatic pressure and maximal inspiratory pressure. Diaphragmatic thickness and thickening can be assessed using ultrasound. Rehabilitation therapies targeting the diaphragm include diaphragmatic breathing, diaphragm-related manual therapy, and phrenic nerve electrical stimulation. Diaphragmatic breathing is safe, simple, and not limited by places. Diaphragmatic manual therapies, which require patient cooperation and one-on-one operation by a professional therapist, are effective. Phrenic nerve electrical stimulation is suitable for patients with severe conditions. These therapies improve the diaphragmatic function, lung function, dyspnea, and exercise capacity of patients with COPD.
CONCLUSION
The diaphragmatic function is commonly assessed in terms of mobility, strength, thickness, and thickening. Diaphragmatic targeted rehabilitation therapies have proven to be efficient, which are recommended to be included in the pulmonary rehabilitation strategy for patients with COPD.
Topics: Diaphragm; Dyspnea; Humans; Phrenic Nerve; Pulmonary Disease, Chronic Obstructive; Ultrasonography
PubMed: 35273448
DOI: 10.2147/COPD.S338583 -
Medicina (Kaunas, Lithuania) Sep 2023Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that affects both the upper and lower motor neurons in the nervous system, causing muscle...
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that affects both the upper and lower motor neurons in the nervous system, causing muscle weakness and severe disability. The progressive course of the disease reduces the functional capacity of the affected patients, limits daily activities, and leads to complete dependence on caregivers, ultimately resulting in a fatal outcome. Respiratory dysfunction mostly occurs later in the disease and is associated with a worse prognosis. Forty-six participants were included in our study, with 23 patients in the ALS group and 23 individuals in the control group. The ultrasound examination of the phrenic nerve (PN) was performed by two authors using a high-resolution "Philips EPIQ 7" ultrasound machine with a linear 4-18 MHz transducer. Our study revealed that the phrenic nerve is significantly smaller on both sides in ALS patients compared to the control group ( < 0.001). Only one significant study on PN ultrasound in ALS, conducted in Japan, also showed significant results ( < 0.00001). These small studies are particularly promising, as they suggest that ultrasound findings could serve as an additional diagnostic tool for ALS.
Topics: Humans; Amyotrophic Lateral Sclerosis; Phrenic Nerve; Neurodegenerative Diseases; Prognosis; Muscle Weakness
PubMed: 37893463
DOI: 10.3390/medicina59101745 -
Journal of Clinical Neuroscience :... Jul 2022Patients with central apnoea may use electro ventilation, provided their phrenic nerves and diaphragm muscles are normal. A tendency towards better survival has been...
Patients with central apnoea may use electro ventilation, provided their phrenic nerves and diaphragm muscles are normal. A tendency towards better survival has been found, and both an improved quality of life and facilitated nursing have been claimed with electro ventilation compared to mechanical ventilation. The high investment for the device may form a hurdle for fund providers like our hospital administration board. We, therefore, from our first patient onwards, collected clinically meaningful data in a special register of all patients using electro ventilation and their controls on mechanical ventilation. Since 1988 172 patients left our institution dependent on a respiratory device. Of these, all 48 patients with preserved phrenic nerves chose phrenic nerve stimulation. A patient on mechanical ventilation who agreed to participate was chosen as a control (n = 44). All patients were seen at least once a year. 90 patients suffered high tetraplegia, and 2 suffered central apnoea for other reasons. There is a tendency towards better survival, and there is a lower frequency of decubital ulcers (0.02) and respiratory tract infections (p0.000) with electro than with mechanical ventilation. The frequency of respiratory infections turned out to be a better measure of the quality of respiratory care than survival. The resulting decrease in the need for airway nursing, and the reduced incidence of respiratory infections repaid the high investment in electro ventilation within one year in our setting. Informed patients prefer electro to mechanical ventilation; fund providers might also agree with this preference.
Topics: Electric Stimulation Therapy; Humans; Phrenic Nerve; Prospective Studies; Quality of Life; Respiration, Artificial; Respiratory Tract Infections; Sleep Apnea, Central
PubMed: 35512426
DOI: 10.1016/j.jocn.2022.04.037 -
Journal of Neurophysiology Dec 2021Phrenic afferents project to brainstem areas responsible for cardiorespiratory control and the mid-cervical spinal cord containing the phrenic motor nucleus. Our purpose...
Phrenic afferents project to brainstem areas responsible for cardiorespiratory control and the mid-cervical spinal cord containing the phrenic motor nucleus. Our purpose was to quantify the impact of small- and large-diameter phrenic afferent activation on phrenic motor output. Anesthetized and ventilated rats received unilateral phrenic nerve stimulation while contralateral phrenic motor output and blood pressure were recorded. Twelve currents of 40-Hz inspiratory-triggered stimulation were delivered (20 s on, 5 min off) to establish current response curves. Stimulation pulse width was varied to preferentially activate large-diameter phrenic afferents (narrow pulse width) and recruit small-diameter fibers (wide pulse width). Contralateral phrenic amplitude was elevated immediately poststimulation at currents above 35 µA for wide and 70 µA for narrow pulse stimulation when compared with animals not receiving stimulation (time controls). Wide pulse width stimulation also increased phrenic burst frequency at currents ≥35 µA, caused a transient decrease in mean arterial blood pressure at currents ≥50 µA, and resulted in a small change in heart rate at 300 µA. Unilateral dorsal rhizotomy attenuated stimulation-induced cardiorespiratory responses indicating that phrenic afferent activation is required. Additional analyses compared phrenic motor amplitude with output before stimulation and showed that episodic activation of phrenic afferents with narrow pulse stimulation can induce short-term plasticity. We conclude that the activation of phrenic afferents ) enhances contralateral phrenic motor amplitude when large-diameter afferents are activated, and ) when small-diameter fibers are recruited, the amplitude response is associated with changes in burst frequency and cardiovascular parameters. Acute, inspiratory-triggered stimulation of phrenic afferents increases contralateral phrenic motor amplitude in adult rats. When small-diameter afferents are recruited, the amplitude response is accompanied by an increase in phrenic burst frequency, a transient decrease in mean arterial blood pressure, and a slight increase in heart rate. Repeated episodes of large-diameter phrenic afferent activation may also be capable of inducing short-term plasticity.
Topics: Afferent Pathways; Animals; Arterial Pressure; Blood Gas Analysis; Electrophysiological Phenomena; Female; Heart Rate; Hemodynamics; Inhalation; Male; Neuronal Plasticity; Neurons, Afferent; Phrenic Nerve; Rats; Rats, Sprague-Dawley
PubMed: 34788165
DOI: 10.1152/jn.00433.2021 -
Annals of Physical and Rehabilitation... Sep 2015Implanted phrenic nerve stimulation is a technique restoring spontaneous breathing in patients with respiratory control failure, leading to being dependent on mechanical... (Review)
Review
Implanted phrenic nerve stimulation is a technique restoring spontaneous breathing in patients with respiratory control failure, leading to being dependent on mechanical ventilation. This is the case for quadriplegic patients with a high spinal cord injury level and for patients with congenital central hypoventilation syndrome. The electrophysiological diaphragm explorations permits better patient selection, confirming on the one hand a definite issue with central respiratory command and on the other hand the integrity of diaphragmatic phrenic nerves. Today there are two different phrenic stimulation techniques: the quadripolar intrathoracic stimulation and the bipolar intradiaphragmatic stimulation. Both techniques allow patients to be weaned off their mechanical ventilator, improving dramatically their quality of life. In fact, one of the systems (phrenic intradiaphragmatic stimulation) was granted social security reimbursement in 2009, and now both are reimbursed. In the future, phrenic intradiaphragmatic stimulation may find its place in the intensive care unit, for patients needing it temporarily, for example, after certain surgeries with respiratory complications as well as diaphragmatic atrophies induced by prolonged mechanical ventilation.
Topics: Contraindications; Diaphragm; Electric Stimulation Therapy; Electrodes, Implanted; Humans; Patient Selection; Phrenic Nerve; Quadriplegia; Respiratory Insufficiency
PubMed: 26260006
DOI: 10.1016/j.rehab.2015.07.001 -
Pain Research & Management 2016Postthoracotomy Ipsilateral Shoulder Pain (IPS) is a common and sometimes intractable pain syndrome. IPS is different from chest wall pain in type, origin, and... (Review)
Review
Postthoracotomy Ipsilateral Shoulder Pain (IPS) is a common and sometimes intractable pain syndrome. IPS is different from chest wall pain in type, origin, and treatments. Various treatments are suggested or applied for it but none of them is regarded as popular accepted effective one. To review data and collect all present experiences about postthoracotomy IPS and its management and suggest future research directions. Search in PubMed database and additional search for specific topics and review them to retrieve relevant articles as data source in a narrative review article. Even in the presence of effective epidural analgesia, ISP is a common cause of severe postthoracotomy pain. The phrenic nerve has an important role in the physiopathology of postthoracotomy ISP. Different treatments have been applied or suggested. Controlling the afferent nociceptive signals conveyed by the phrenic nerve at various levels-from peripheral branches on the diaphragm to its entrance in the cervical spine-could be of therapeutic value. Despite potential concerns about safety, intrapleural or phrenic nerve blocks are tolerated well, at least in a selected group of patient. Further researches could be directed on selective sensory block and motor function preservation of the phrenic nerve. However, the safety and efficacy of temporary loss of phrenic nerve function and intrapleural local anesthetics should be assessed.
Topics: Analgesia, Epidural; Functional Laterality; Humans; Pain, Postoperative; PubMed; Shoulder Pain; Thoracotomy
PubMed: 28018130
DOI: 10.1155/2016/3652726 -
Europace : European Pacing,... Apr 2023This study aimed to evaluate the feasibility of real-time visualization and mapping of the right phrenic nerve (RPN) by using intracardiac echocardiography (ICE) during...
OBJECTIVE
This study aimed to evaluate the feasibility of real-time visualization and mapping of the right phrenic nerve (RPN) by using intracardiac echocardiography (ICE) during atrial fibrillation (AF) ablation.
BACKGROUND
RPN injury is a complication associated with the ablation of AF. Multiple approaches are currently being used to prevent and detect RPN injuries. However, none of these approaches can directly visualize the RPN in real-time during the ablation procedure.
METHODS AND RESULTS
The RPN was detected using ICE. The RPN and its adjacent structures were analysed. The relationship between the RPN's distance from the superior vena cava (SVC) and its pacing capture threshold was quantified. The safety of SVC isolation guided by the ICE-visualized RPN was evaluated. Thirty-eight people were enrolled in this study. The RPN was visualized by ICE in 92% of patients. It ran through the space between the SVC and the mediastinal pleura and had a 'straw'-like appearance upon ICE imaging. The course of the RPN was close to the SVC (minimum 1.0 ± 0.4 mm) and the right superior pulmonary vein (minimum 14.1 ± 7.3 mm). There was a positive linear correlation between the RPN's capture threshold and its distance from the SVC (Spearman's correlation coefficient = 0.728, < 0.001). SVC isolation was guided by the RPN; none of the patients developed an RPN injury.
CONCLUSIONS
RPN can be visualized by ICE in most patients, thus providing a novel approach for the real-time detection of RPN during AF ablation.
Topics: Humans; Atrial Fibrillation; Phrenic Nerve; Vena Cava, Superior; Catheter Ablation; Echocardiography; Pulmonary Veins
PubMed: 36857524
DOI: 10.1093/europace/euad012