///2009 Abstract Details
2009 Abstract Details2019-08-03T15:55:31-05:00

Nocebo induced-hyperalgesia during local anesthetic injection

Abstract Number: 54
Abstract Type: Original Research

Dirk Varelmann MD, DESA1 ; Carlo Pancaro MD2; Eric C Cappiello MD3; William R Camann MD4

Rationale: Expectation of a negative outcome may induce worsening of a symptom, a phenomenon known as the Nocebo effect. Use of "negative words" in the post-operative period can significantly increase opioid consumption and aggravate a stress response (1). Other studies showed that warning patients of painful sensations and offering sympathy increased the level of pain and discomfort (2). It is standard practice to administer a local anesthetic (LA) skin wheal injection prior to a neuraxial block for labor or cesarean delivery. The standard phrase used during the skin wheal at our institution is: "It feels like a big burning bee sting, this is the worst part of the procedure". Our hypothesis was, that using gentler words may improve the patients experience by decreasing pain during LA injection.

Methods: 88 healthy parturients at term gestation requesting epidural analgesia for labor or presenting for elective cesarean section were randomly assigned to either a "Placebo" or "Nocebo" group. The placebo group was told "We are going to give you a local anesthetic that will numb the area where we are going to do the epidural/spinal anesthesia and you will be comfortable during the procedure". The nocebo group was told "You are going to feel a big sting and burn in your back now, like a big bee-sting; this is the worst part of the procedure". A blinded observer assessed pain using a 0-10 verbal analog scale (VAS), immediately after the LA injection. Statistical analysis was performed using Mann-Whitney test (non-parametric), a p<0.05 was considered significant.

Results: The VAS for the skin wheal are presented in the figure. We found a significant reduction in VAS pain scores when the reassuring words were used to describe the procedure compared to the harsher nocebo words.

Conclusion: The words we use during invasive procedures can have meaningful impact on the patients subjective perception of the experience. It is commonly believed that informing patients of a worst-case (e.g., "big burning bee sting") scenario is the best way to explain such procedures. Our data suggests that using gentler, more reassuring words can actually improve the subjective experience during invasive procedures. This has important implications on patient/provider interactions.


1 Wang et al, Minerva Anestesiol 2008

2 Lang et al, Pain 2005

SOAP 2009