Invasive placebos in research on peripheral nerve blocks: a follow-up study.

Area of Science:

• Anesthesiology
• Clinical Research Ethics
• Medical Device Safety

Background:

• The Serious Harm and Morbidity (SHAM) grading system was developed to assess risks of invasive placebos in peripheral nerve block studies.
• A 2011 study found 52% of peripheral nerve block studies used SHAM grades of 3 or higher, indicating significant risk.

Purpose of the Study:

• To re-evaluate the SHAM grades in recent peripheral nerve block research.
• To compare current practices with the 2011 findings regarding the use of invasive placebos.

Main Methods:

• A systematic review of randomized controlled studies of peripheral nerve blocks published in English over 22 months.
• SHAM grading was applied to assess the risk of invasive placebos.
• Data on study participants, controls, body region, adverse events, and ethical discussions were collected.

Main Results:

• 114 studies were analyzed; 33.3% had SHAM grades of 3 or higher (38 studies, 1494 patients).
• No pediatric studies utilized SHAM grades of 3 or higher.
• Some studies discussed the rationale for selecting non-invasive placebos.

Conclusions:

• The proportion of peripheral nerve block studies employing high-risk invasive placebos (SHAM grade ≥3) has decreased since 2011.
• Contemporary research demonstrates a trend towards reduced use of potentially harmful invasive placebos in this field.