Threshold Currents of Platinum Electrodes used for Functional Electrical Stimulation of the Phrenic Nerves for Treatment of Central Apnea

[S3 Guideline: Treating Chronic Respiratory Failure with Non-invasive Ventilation]

The S3 guideline on non-invasive ventilation as a treatment for chronic respiratory failure was published on the website of the Association of the Scientific Medical Societies in Germany (AWMF) in July 2024. It offers comprehensive recommendations for the treatment of chronic respiratory failure in various underlying conditions, such as COPD, thoraco-restrictive diseases, obesity-hypoventilation syndrome, and neuromuscular diseases. An important innovation is the separation of the previous S2k guideline dating back to 2017, which included both invasive and non-invasive ventilation therapy. Due to increased scientific evidence and a significant rise in the number of affected patients, these distinct forms of therapy are now addressed separately in two different guidelines.The aim of the guideline is to improve the treatment of patients with chronic respiratory insufficiency using non-invasive ventilation and to make the indications and therapy recommendations accessible to all involved in the treatment process. It is based on the latest scientific evidence and replaces the previous guideline. This revised guideline provides detailed recommendations on the application of non-invasive ventilation, ventilation settings, and the subsequent follow-up of treatment.In addition to the updated evidence, important new features of this S3 guideline include new recommendations on patient care and numerous detailed treatment pathways that make the guideline more user-friendly. Furthermore, a completely revised section is dedicated to ethical issues and offers recommendations for end-of-life care. This guideline is an important tool for physicians and other healthcare professionals to optimize the care of patients with chronic respiratory failure. This version of the guideline is valid for three years, until July 2027.

Restoring hand functions in people with tetraplegia through multi-contact, fascicular and auto-pilot stimulation: a proof-of-concept demonstration

Two multi-contact epineural electrodes were placed around radial and median nerves of 2 subjects with high tetraplegia C4, AIS A, group 0 of the International Classification for Surgery of the Hand in Tetraplegia. The purpose was to study the safety and capability of these electrodes to generate synergistic motor activation and functional movements and to test control interfaces that allow subjects to trigger pre-programmed stimulation sequences. The device consists of a pair of neural cuff electrodes and percutaneous cables with two extracorporeal connection cables inserted during a surgical procedure and maintained for 28 days. Continuity tests of the electrodes, selectivity of movements induced, motor capacities for grasping and gripping, conformity of the control order, tolerance and acceptability were assessed. Neither of the 2 participants showed general and local comorbidity. Acceptability was optimal. None of the stimulation configurations generated contradictory movements. The success rate in task execution by the electro-stimulated hand exceeded the target of 50% (54% and 51% for patient 1 and 2 respectively). The compliance rate of the control orders in both patients was > 90% using motion IMU-based detection and 100% using EMG-based detection in patient 1. These results support the relevance of neural stimulation of the tetraplegic upper limb with a more selective approach, using multi-contact epineural electrodes with 9 and 6 contact points for the median and radial nerve respectively.

The terminal segment of the human phrenic nerve as a novel implantation site for diaphragm pacing electrodes: Anatomical and clinical description

BACKGROUND

Diaphragm pacing allows certain ventilator-dependent patients to achieve weaning from mechanical ventilation. The reference method consists in implanting intrathoracic contact electrodes around the phrenic nerve during video-assisted thoracic surgery, which involves time-consuming phrenic nerve dissection with a risk of nerve damage. Identifying a phrenic segment suitable for dissection-free implantation of electrodes would constitute progress.

STUDY DESIGN

This study characterizes a free terminal phrenic segment never fully described before. We conducted a cadaver study (n = 14) and a clinical observational study during thoracic procedures (n = 54).

RESULTS

A free terminal phrenic segment was observed on both sides in 100% of cases, "jumping" from the pericardium to the diaphragm and measuring 60 mm [95% confidence interval; 48-63] and 72.5 mm [65-82] (right left, respectively; p = 0.0038; cadaver study). This segment rolled up on itself at end-expiration and became unravelled and elongated with diaphragm descent (clinical study). Three categories of fat pads were defined (type 1: pericardiophrenic bundle free of surrounding fat; type 2: single fatty fringe leaving the phrenic nerve visible until diaphragmatic entry; type 3: multiple fatty fringes masking the site of penetration of the phrenic nerve) that depended on body mass index (p = 0.001, clinical study). Hematoxylin-eosin and toluidine blue staining (cadaver study) showed that all of the phrenic fibers in the distal, pre-branching part of the terminal segment were contained within a single epineurium containing a variable number of fascicles (right: 1 [95%CI 0.65-4.01]; left 5 [3.37-7.63]; p = 0.03).

CONCLUSION

Diaphragm pacing through periphrenic electrodes positioned on the terminal phrenic segment should be tested.

Long-Term Mechanical Ventilation: Recommendations of the Swiss Society of Pulmonology

Long-term mechanical ventilation is a well-established treatment for chronic hypercapnic respiratory failure (CHRF). It is aimed at improving CHRF-related symptoms, health-related quality of life, survival, and decreasing hospital admissions. In Switzerland, long-term mechanical ventilation has been increasingly used since the 1980s in hospital and home care settings. Over the years, its application has considerably expanded with accumulating evidence of beneficial effects in a broad range of conditions associated with CHRF. Most frequent indications for long-term mechanical ventilation are chronic obstructive pulmonary disease, obesity hypoventilation syndrome, neuromuscular and chest wall diseases. In the current consensus document, the Special Interest Group of the Swiss Society of Pulmonology reviews the most recent scientific literature on long-term mechanical ventilation and provides recommendations adapted to the particular setting of the Swiss healthcare system with a focus on the practice of non-invasive and invasive home ventilation in adults.

Video-assisted thoracoscopic implantation of a diaphragmatic pacemaker in a child with tetraplegia: indications, technique, and results

We report the case of a child with tetraplegia after cervical trauma, who subsequently underwent diaphragmatic pacemaker implantation. We reviewed the major indications for diaphragmatic pacing and the types of devices employed. We highlight the unequivocal benefit of diaphragmatic pacing in the social and educational reintegration of individuals with tetraplegia.