Placebo Versus Nocebo: Effects on Pain and Anxiety During Local Anaesthetic Infiltration in Parturient Undergoing Elective Caesarean Delivery

NCT ID: NCT04975659

Last Updated: 2023-05-19

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 76 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2020-07-13
• Study Completion Date: 2021-05-28

Brief Summary

This randomized trial compared placebo and nocebo effect over anaesthetist-patient communication on pain and anxiety score during local anaesthetic (LA) skin infiltration in parturient undergoing caesarean delivery under regional anaesthesia (RA). A secondary objective was to determine if education level and previous RA experience affect pain and anxiety scores. Parturients scheduled for elective caesarean delivery were randomised into Placebo (P) or Nocebo (N) group. Baseline Amsterdam Preoperative Anxiety & Information Scale (APAIS0) were obtained. Standardised scripts describing the LA skin infiltration for RA were used during the pre-anaesthetic review. (N) group were explained with words like "pain, prick, sharp" while words like "numb, comfort, tolerable" were used in the (P) group, avoiding "painful" expressions. The same scripts will be repeated before skin infiltration during the RA procedure. On the day of surgery, a second (APAIS1) was obtained upon arrival to the theatre. Pain score using the numerical rating scale (NRS) was assessed after LA infiltration.

Detailed Description

We randomised participants into either the nocebo (N) or placebo (P) group. We obtained a baseline anxiety score (APAIS0) using the Amsterdam Preoperative Anxiety and Information Scale (APAIS) during the pre-anaesthesia visit. Following that, we informed subjects in the N group a negative suggestion, using the following script: "During the local anaesthetic injection, you are going to feel a sharp prick at your back; this is usually the most painful part of the procedure". On the other hand, we used a positive suggestion on the P group: "We will administer some local anaesthetic to numb your back; this will allow the procedure to be more comfortable and tolerable for you." We obtain a second anxiety score (APAIS1) in the operating theatre before the caesarean section. We carried out either spinal anaesthesia or continuous spinal epidural according to standard hospital protocol and indication. Before the LA skin infiltration, the anaesthetist repeats the same script to the subjects according to the prior randomisation. Five millilitres of lignocaine 2% is injected intradermally and subcutaneously by the anaesthetist into interspinous space in a single pass through a 22-gauge needle to create a skin wheal.

During the LA infiltration, only the attending anaesthetist performing the procedure gave participants verbal instructions; other personnel remained silent throughout. We recorded the presence of vocalisation of pain, withdrawal movement or facial grimacing. Immediately after the LA infiltration, a blinded and trained general anaesthetic nurse or personnel enters the operating theatre to assess the subjects' pain score using the numerical rating scale (NRS). After collection of the pain score, the anaesthetist performed the remaining anaesthetic procedure as per clinical routine.

Conditions

Communication

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: SUPPORTIVE_CARE
• Blinding Strategy: DOUBLE

Study Groups

Nocebo

We informed subjects in the N group a negative suggestion, using the following script: "During the local anaesthetic injection, you are going to feel a sharp prick at your back; this is usually the painful part of the procedure"

Group Type: ACTIVE_COMPARATOR

Placebo and Nocebo effect

Intervention Type: BEHAVIORAL

Positive suggestion and words is used on Placebo group Negative suggestion and words is used on Nocebo group

Placebo

We informed subjects in the P group a positive suggestion, using the following script: "We will administer some local anaesthetic to numb your back; this will allow the procedure to be more comfortable and tolerable for you."

Group Type: PLACEBO_COMPARATOR

Placebo and Nocebo effect

Intervention Type: BEHAVIORAL

Positive suggestion and words is used on Placebo group Negative suggestion and words is used on Nocebo group

Interventions

Placebo and Nocebo effect

Positive suggestion and words is used on Placebo group Negative suggestion and words is used on Nocebo group

Intervention Type: BEHAVIORAL

Eligibility Criteria

Inclusion Criteria

• American Society of Anaesthesiology (ASA) II category parturient listed for elective caesarean delivery.
• Can understand intended verbal communication

Exclusion Criteria

• receiving any form of analgesia within 6 hours before the study
• chronic pain,
• anxiety disorders
• allergy to Local Anaesthetic drugs

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 45 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: No

Sponsors

Universiti Kebangsaan Malaysia Medical Centre

OTHER

Sponsor Role: lead

Responsible Party

Rufinah Teo

Lecturer and Consultant Anesthesiologist , Department of Anesthesia and Intensive Care

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Hospital Canselor Tuanku Muhriz,

Cheras, Kuala Lumpur, Malaysia

Countries

Malaysia

References

Mohd Fahmi Z, Lai LL, Loh PS. Validation of the Malay version of the Amsterdam Preoperative Anxiety and Information Scale (APAIS). Med J Malaysia. 2015 Aug;70(4):243-8.

Reference Type: BACKGROUND

PMID: 26358022 (View on PubMed)

Dutt-Gupta J, Bown T, Cyna AM. Effect of communication on pain during intravenous cannulation: a randomized controlled trial. Br J Anaesth. 2007 Dec;99(6):871-5. doi: 10.1093/bja/aem308. Epub 2007 Oct 30.

Reference Type: BACKGROUND

PMID: 17977860 (View on PubMed)

Varelmann D, Pancaro C, Cappiello EC, Camann WR. Nocebo-induced hyperalgesia during local anesthetic injection. Anesth Analg. 2010 Mar 1;110(3):868-70. doi: 10.1213/ANE.0b013e3181cc5727. Epub 2009 Dec 30.

Reference Type: RESULT

PMID: 20042440 (View on PubMed)

Moerman N, van Dam FS, Muller MJ, Oosting H. The Amsterdam Preoperative Anxiety and Information Scale (APAIS). Anesth Analg. 1996 Mar;82(3):445-51. doi: 10.1097/00000539-199603000-00002.

Reference Type: RESULT

PMID: 8623940 (View on PubMed)

Other Identifiers

UKM PPl/111/8/JEP-2020-011

Identifier Type: -

Identifier Source: org_study_id