What Is a Diaphragm Pacing System?

A diaphragm is the main muscle of respiration. It is located below the lungs. The diaphragm is a large, dome-shaped muscle that contracts involuntarily, rhythmically, and continuously. Upon inhalation, the diaphragm contracts and flattens, and then, the chest cavity enlarges. This contraction creates a vacuum, which pulls air into the lungs. Upon exhalation, the diaphragm relaxes and returns to its domelike shape, and the air is forced out of the lungs.

The diaphragm pacing system (DPS) procedure is usually performed under general anesthesia. After the patient is unconscious, his vital parameters are monitored and procedure is started.

• The surgeon usually creates four to five dime-size holes in the abdominal region.
• A laparoscope (tube with a camera) will be inserted so that the diaphragm muscle can be observed.
• The electrodes are surgically attached to the phrenic nerves on each side of the neck or in the chest.
• The receivers for the stimulus are surgically placed under the skin in the chest or under the skin of the neck.
• The antennae are taped on the chest over the receivers.
• When turned on, the transmitter sends a signal to the receivers through the antennae. 
• The external transmitter generates electrical energy like radio wave signals. This energy is converted to electrical current which is conducted to the phrenic nerves on both sides.
• The nerve stimulation causes the diaphragm muscles to contract and the person takes a breath in. 
• This cycle repeats for a fixed number of breaths needed each minute. This number is manually set.
• A proper contraction of diaphragm via external stimulation is checked before the procedure is terminated.
• DPS procedure usually works on a battery that is generally changed every three weeks.
• After the procedure, the laparoscope is removed, and wounds are covered with bandage. This entire procedure is completed within 90 minutes.

A diaphragm pacing system (DPS) is recommended for:

• Patients who are at least 18 years of age or older and can be committed to DPS treatment.
• Patients with a cervical spinal cord injury and who are dependent on mechanical ventilation.
• Patients who are clinically stable following a spinal cord injury.
• Have a committed primary caregiver (caregiver will be required to devote several hours during the day operating the system).
• Female patients (of childbearing age) must have a negative pregnancy test.
• Patients with a normal or almost normal lung functions.

A diaphragm pacing system (DPS) is not recommended for:

• Patients who have any medical conditions which would interfere with the surgery.
• Patients with active lung disease, heart disease, or brain disease.
• Patients who require supplemental oxygen use.
• Patients who have been hospitalized or treated for an active infection within the last three months before DPS procedure.
• Patients with a significant chest deformity (scoliosis).
• Females who are currently pregnant or breastfeeding.
• Overweight patients.
• Patients who do not have a care taker.

Patients on mechanical ventilation usually opt for a diaphragm pacing system (DPS) because of the following benefits:

• DPS decreases secretions.
• It helps in decreasing lung infections.
• DPS decreases lifetime costs (only need one ventilator instead of two).
• Increases life expectancy and quality of life.
• Helps patient to breathe more naturally due to which patient’s speech is improved.
• Patient can continue daily activities with minimum effort.
• Improves patients’ sense of smell and taste.

The risks involved in diaphragm pacing system:

• Pain and spasm at the surgical site
• Nausea after the anesthesia
• Rare damage to internal organs 
• The expected risks with any general anesthesia (headache and drowsiness)