Research encourages re-evaluation of special nerve treatment for chronic pain

Hospital researchers from Lawson Health Research Institute have published a recent study that assessed the use of a specialized treatment for chronic pain and its impact on health care use and opioid prescribing.   


Paravertebral blocks (PVBs) belong to a broader group of procedures called “nerve blocks.” A recent Toronto Star report noted that OHIP has been billed $420 million for nerve block procedures since 2011. PVBs involve injecting medication around the nerves where they exit the bones of the spine, at different locations depending on the patient and the chronic pain they are experiencing.  

The regular use of these procedures has been questioned by health care providers due to the high cost and limited evidence of their benefit in reducing chronic pain. While the effectiveness of PVBs has been examined in trauma, cancer pain and regional anesthesia during surgery, they have not been evaluated for use in chronic pain despite widespread use in Ontario.  

It is estimated that one in five Canadians live with chronic pain. Pain that persists can affect all aspects of someone’s life and health, particularly when it is not being managed.  

The study, “A Retrospective Cohort Study of Healthcare Utilization Associated with Paravertebral Blocks for Chronic Pain Management in Ontario,” published in the Canadian Journal of Pain, found that 66,310 patients had a PVB between July 2013 and March 2018, and 47,723 patients were included in the study. In the year after a patient’s first PVB, there was a significant increase in the number of physician visits. Additional PVBs were frequently performed after the first treatment, with over 26 per cent of patients receiving a PVB ten or more times in one year, with almost eight per cent of patients receiving 30 or more. No overall change was found in opioid dosage in the year after PVB was initiated compared to the year before. 

“Frequent use of PVB is common. Initiating treatment with PVCs is associated with marked increases in health care utilization, which includes physician visits and other injection procedures,” explains Dr. Eldon Loh, Lawson Associate Scientist and Physiatrist at St. Joseph’s Health Care London. 

This research provides a broad perspective on the use of PVBs in Ontario, and on the use of nerve blocking treatments in general. There has been a concern for several years about the over use of these procedures; however, this is the first study to systematically document the impact on health care utilization and opioid use. 

"We hope that from this study, the appropriate use of PVBs and other pain interventions will be re-evaluated at a provincial level to ensure the use of health resources is being properly managed and we achieve the best outcome for patients,” Dr. Loh adds.