Percutaneous Electrical Nerve Stimulation (PENS) of the auricle for acute pain management post cardiac surgery

A well formulated analgesic protocol is fundamental to fast tracking post cardiac surgery. Traditional analgesic methods have their own set of drawbacks unique to cardiac surgery. Opioids have well established side effects like nausea, vomiting, respiratory depression, urinary retention. Regional anesthetic techniques in anti coagulated patients may result in potentially catastrophic neurological, bleeding and thromboembolic sequelae. Non steroidal Anti Inflammatory Drugs (NSAIDs) have been associated with increased cerebrovascular events, renal dysfunction, sternal wound infections. These make alternative therapies, including non pharmacological modalities, attractive options for optimal analgesic therapy during the post operative period.

Alternative methods like topical application of COX -2 inhibitors, intravenous magnesium, Transcutaneous Electrical Nerve Stimulation (TENS) have been tried with varied results in cardiac surgery. A somatotopic relationship has been described between the auricle and the other anatomical regions of the body. When specific points are accurately identified along the meridians of the ear and stimulated electrically, analgesic effects are known to occur. Percutaneous Electrical Nerve Stimulation (PENS) of the auricle and its efficacy in management of post midline sternotomy pain has not been evaluated previously. Primary Relief v 2.0 is a device which provides continuous PENS aimed at non pharmacological post operative pain management.

Inclusion Criteria:

• Cardiac surgery patient with midline sternotomy incision

Exclusion Criteria:

1. Thoracotomy incisions
2. Patients with pacemakers,
3. Post operative cognitive dysfunction
4. Anticipated ventilation > 24 hrs
5. Pre operative opioid therapy
6. Ear infections
7. Skin lesions / allergy to adhesive materials
8. Re-exploration for any reason