Image Guidance and Nerve Blocks

Some level of image guidance needed for almost all nerve blocks, says draft Standard

In response to issues with the administration of nerve blocks in some Out-of-Hospital Premises (OHP) pain clinics, CPSO developed a draft Standard to clearly articulate its expectations about the standard of care. Council released the draft document for external consultation and engagement. 

The issue addressed in the draft reflects ongoing tension within the profession about the appropriate standard of care when administering nerve blocks for adult chronic pain. In particular, there is disagreement about whether the use of image guidance is required and the type of imaging required for particular nerve blocks. There are two distinct approaches in practice: one involves a technique called landmarking and the other involves using image guidance. 

Some physicians practising in interventional pain management generally prefer the landmarking approach, which does not involve the use of image guidance. Advocates of this approach often note access to care is significantly improved by adopting this approach.

Other physicians believe image guidance is essential to ensure appropriate needle placement and that the injection is delivered to the target. 

The draft Standard reflects that the standard of care includes the use of some level of image guidance when administering almost all nerve blocks in this context to ensure appropriate needle placement and that the injection is delivered to the target. 

“The use of image guidance is widely accepted as a critical component of administering nerve blocks in order to reduce the risk of complications, ensure the injection is delivered to the target and enhance patient safety,” states the draft Standard.

In particular, the intention of the draft Standard is to require image guidance for all nerve blocks (at minimum, use of ultrasound) except superficial facial blocks, and signal that in some circumstances a higher level of imaging will be required in order to meet the standard of care (i.e., CT and/or fluoroscopy). 

The draft Standard reflects that available research, best practices, and other regulators who similarly regulate facilities and practices of this nature (e.g., College of Physicians and Surgeons of British Columbia) all consider image guidance to be critical when administering nerve blocks for chronic pain. 

The divergence in approaches to practice is relatively unique to Ontario, and in many ways is an artifact of the billing framework in the province as the Schedule of Benefits does not require use of image guidance when billing for these procedures.

It has been a longstanding issue in cases seen by CPSO’s Premises Inspection Committee and multiple attempts have been made to reach consensus, including through consultation and engagement with physicians and stakeholders who hold different perspectives. Consensus has not been possible to this point.

Dr. Gillian Oliver, chair of the Premises Inspection Committee, says the development of this draft Standard was necessary to ensure patient safety and appropriate pain practice. OHP inspections, she said, are identifying concerns in the quality of care occurring in some OHPs where interventional pain procedures are performed.

“Without image guidance, there is uncertainty as to whether physicians are  correctly administering the nerve blocks they are claiming to provide to  patients and which they are billing for,” said Dr. Oliver, a Kitchener obstetrician/gynecologist. She said that without image guidance, physicians may be inadvertently administering trigger point injections (blocks delivered to the muscle instead of the nerve). 

In some cases, she said, inspections have found an unnecessarily high number of blocks are being administered to patients without clear clinical indication.

Beyond the minimum requirement of image guidance, there are generally only  “recommendations” or “best practices” regarding the types of imaging that should be  used for each nerve block in the literature. While the draft Standard does not  reference specific Clinical Practice Guidelines in the document, it does reference the Spine Intervention Society’s recommendations in the accompanying Frequently Asked Questions, which identify the categories of nerve blocks that may require a higher level of imaging.

Over the last three years, CPSO adopted a right-touch regulation approach that has moved us away from detailed, prescriptive requirements and towards a more principle-based approach toward regulation. In this instance, a prescriptive Standard has been developed to ensure the standard of care is clear, the risks are appropriately managed and patient safety is not being compromised, said Laurie Reid, CPSO’s Director of Investigations and Accreditation. 

“Historically, we have allowed and relied on professional judgment to guide decisions about what is appropriate. However, given the pervasiveness, and extent of the disagreement and the risk of patient harm that may result, a clear Standard is an example of CPSO exerting the right tools, with the right force, for the right problem,” said Ms. Reid.  

Should the Standard ultimately be approved following any revisions made in light of consultation feedback, physicians impacted by its implementation will be given an opportunity to comply with the requirements and to make any necessary arrangements to ensure patients are not unduly impacted.