Phrenic Nerve Pacing or diaphragm pacing, is the rhythmic application of electrical impulses to the diaphragm, resulting in respiration for patients who would otherwise be dependent on a mechanical ventilator.

This concept was originally referred to as electrophrenic respiration, although the Food and Drug Administration

Food and Drug Administration

The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...

 identifies the device as a “diaphragmatic/phrenic nerve stimulator”. A phrenic nerve pacemaker is a Class III medical device which requires premarket approval. It should not be confused with an experimental device currently under development (see “diaphragmatic pacemaker

Diaphragmatic pacemaker

A diaphragmatic pacemaker, in medicine, is a surgically-implanted device used to help patients breathe following complications from spinal cord injuries. The device works through pacing of the diaphragm.-Mechanism:...

”) at Case Western Reserve University.

Indications for Use

According to Medicare

Medicare (United States)

Medicare is a social insurance program administered by the United States government, providing health insurance coverage to people who are aged 65 and over; to those who are under 65 and are permanently physically disabled or who have a congenital physical disability; or to those who meet other...

, phrenic nerve stimulators are indicated for “selected patients with partial or complete respiratory insufficiency” and “can only be effective if the patient has an intact phrenic nerve and diaphragm.” (Medicare National Coverage Determinations Manual, Chapter 1, Part 2, Section 160.19) Common patient diagnoses for phrenic nerve pacing include patients with spinal cord injury

Spinal cord injury

A spinal cord injury refers to any injury to the spinal cord that is caused by trauma instead of disease. Depending on where the spinal cord and nerve roots are damaged, the symptoms can vary widely, from pain to paralysis to incontinence...

, central sleep apnea

Sleep apnea

Sleep apnea is a sleep disorder characterized by abnormal pauses in breathing or instances of abnormally low breathing, during sleep. Each pause in breathing, called an apnea, can last from a few seconds to minutes, and may occur 5 to 30 times or more an hour. Similarly, each abnormally low...

 (ie, Ondine's curse

Ondine's curse

Ondine's Curse, also called congenital central hypoventilation syndrome or primary alveolar hypoventilation, is a respiratory disorder that is fatal if untreated...

), and diaphragm paralysis.

Surgery

The surgery is performed by placing an electrode around the phrenic nerve

Phrenic nerve

The phrenic nerve originates mainly from the 4th cervical nerve, but also receives contributions from the 5th and 3rd cervical nerves in humans....

, either in the neck

Neck

The neck is the part of the body, on many terrestrial or secondarily aquatic vertebrates, that distinguishes the head from the torso or trunk. The adjective signifying "of the neck" is cervical .-Boner anatomy: The cervical spine:The cervical portion of the human spine comprises seven boney...

 (ie, cervically), or in the chest

Chest

The chest is a part of the anatomy of humans and various other animals. It is sometimes referred to as the thorax or the bosom.-Chest anatomy - Humans and other hominids:...

 (ie, thoracically). This electrode is connected to a radiofrequency receiver which is implanted just under the skin. An external transmitter sends radio signals to the device by an antenna which is worn over the receiver.

For the cervical surgical technique, the phrenic nerve is approached via a small (~5 cm) incision slightly above, and midline to, the clavicle. The phrenic nerve is then isolated under the scalenus anticus muscle.

For the thoracic surgical technique, a small (~5 cm) incisions over the 2nd or 3rd intercostal space. The electrodes are placed around the phrenic nerves alongside the pericardium. Use of a thorascope

Endoscopy

Endoscopy means looking inside and typically refers to looking inside the body for medical reasons using an endoscope , an instrument used to examine the interior of a hollow organ or cavity of the body. Unlike most other medical imaging devices, endoscopes are inserted directly into the organ...

 allows for this technique to be performed in a minimally-invasive

Minimally invasive procedure

There are three main categories which describe the invasiveness of surgical procedures. These are: non-invasive procedures, minimally invasive procedures, and invasive procedures ....

manner.

Patients are usually hospitalized for 1-3 days post-operatively, although some implantations can be performed on an outpatient basis.

Availability

There are currently two commercially distributed phrenic nerve stimulators made by Avery Biomedical Devices, Inc. (USA) and Atrotech OY (Finland). The Avery device (“Mark IV Breathing Pacemaker”) is distributed worldwide. The Atrotech device (“Atrostim Jukka”) is not available in the United States.