Intramuscular diaphragm stimulation for ventilator-dependent chronic respiratory failure from high spinal cord injuries

Evidence-based recommendations on intramuscular diaphragm stimulation for ventilator-dependent chronic respiratory failure from high spinal cord injuries. This involves keyhole abdominal surgery. The aim is to stimulate and possibly strengthen the diaphragm to help people breathe without a ventilator.

# Recommendations
Intramuscular diaphragm stimulation for ventilator-dependent chronic respiratory failure from high spinal cord injuries should only be used with special arrangements for clinical governance, consent, and audit or research. Find out what special arrangements mean on the NICE interventional procedures guidance page.
Clinicians wanting to do intramuscular diaphragm stimulation for ventilator-dependent chronic respiratory failure from high spinal cord injuries should:
Inform the clinical governance leads in their healthcare organisation.
Ensure that people (and their families and carers as appropriate) understand the procedure's safety and efficacy, and any uncertainties about these.
Take account of NICE's advice on shared decision making and NICE's information for the public.
Audit and review clinical outcomes of everyone having the procedure. The main efficacy and safety outcomes identified in this guidance can be entered into NICE's interventional procedure outcomes audit tool (for use at local discretion).
Discuss the outcomes of the procedure during their annual appraisal to reflect, learn and improve.
Healthcare organisations should:
Ensure systems are in place that support clinicians to collect and report data on outcomes and safety for everyone having this procedure.
Regularly review data on outcomes and safety for this procedure.
Patient selection should be done by a multidisciplinary team with experience in managing high spinal cord injury and in managing home ventilation.
The procedure should only be done by surgeons with experience and training in this procedure.
Report any problems with a medical device using the Medicines and Healthcare products Regulatory Agency's Yellow Card Scheme.
Further research should be randomised controlled trials or observational data from registries or other sources of real-world evidence.
Why the committee made these recommendations
The evidence for this procedure is limited because there is a lack of long-term data and no high-quality clinical trials. But the evidence does suggest that this procedure may improve quality of life and enable people to have some ventilator-free time each day. The evidence on safety includes reports of electrode insertion site infection and pneumonia, but it is not certain if pneumonia is directly caused by the procedure. More research will offer more evidence on safety and long-term outcomes.
High spinal cord injury is severely disabling. For people who are dependent on mechanical ventilation, this procedure offers one of few options that could enable them to have some ventilator-free time. So, this procedure is recommended but only with special arrangements.# The condition, current treatments and procedure

# The condition
High spinal cord injuries can damage the nerves that control breathing and cause chronic respiratory failure.

# Current treatments
Standard care for managing chronic respiratory failure in people with high spinal cord injuries includes non-invasive forms of ventilation support (such as bi-level positive airway pressure). In advanced stages of respiratory failure, mechanical ventilation is done through a permanent tracheostomy. Phrenic nerve pacing is an alternative treatment for people who have intact phrenic nerves (the nerves that contract the diaphragm). The diaphragm is stimulated to contract by electrodes placed on the phrenic nerve in the neck or thorax.

# The procedure
The aim of intramuscular diaphragm stimulation is to make the diaphragm contract, enabling a full or partial weaning from mechanical ventilation. This procedure needs intact phrenic nerve function. It avoids the need to access the phrenic nerve through the neck or thorax, as well as reducing the risk of phrenic nerve damage.
The procedure is done laparoscopically with general anaesthesia. Areas of the diaphragm where minimal electrical stimulation causes maximal diaphragm contraction (known as the motor points) are mapped. Two intramuscular electrodes are implanted on the abdominal surface of each hemi-diaphragm at the motor points. The electrode leads are tunnelled subcutaneously to an exit site in the chest where they are connected to an external battery-powered pulse generator. A reference electrode (anode) is also implanted, and the leads tunnelled with the other electrodes. Intraoperative stimulation and voltage calibration tests are done to confirm there is adequate contraction of the diaphragm. After implantation the person follows a diaphragm conditioning programme, which involves progressive use of the system for increasing periods of time with gradual weaning from the ventilator.