Intraoperative Pain Sensation During Cataract Surgery: Why Does Timing Matter?

ABSTRACT

Purpose: To investigate whether timing influences pain perception during cataract surgery and to investigate the possible mechanisms.

Methods: Patients scheduled for cataract surgery both in the morning and afternoon were consecutively enrolled. Questionnaires to evaluate anxiety, including the Simplified State–Trait Anxiety Inventory, Amsterdam Preoperative Anxiety and Information Scale, and a visual analogue scale (VAS) for anxiety, were completed preoperatively, whereas a VAS for pain and the Wong–Baker FACES® Pain Rating Scale questionnaire were completed after surgery. Preoperative blood pressure and heart rate were recorded. Blood samples were acquired before surgery, and plasma cortisol, adrenocorticotropic hormone, adrenalin, and noradrenalin were tested.

Results: Fifty-five patients underwent uneverntful cataract surgery (28 in the morning and 27 in the afternoon) were included in the final analysis. Greater intraoperative pain perception during cataract surgery was reported in the afternoon than in the morning. Overall anxiety levels were significantly higher in the afternoon. Plasma adrenalin levels were significantly higher in the afternoon. Cortisol levels were higher in the afternoon. Preoperative anxiety levels were closely related to intraoperative pain perception. Both adrenalin and cortisol correlated positively with preoperative anxiety, but only adrenalin correlated significantly with the pain scores.

Conclusions: Patients undergoing cataract surgery in the afternoon showed more preoperative anxiety, which may have increased their relevant stress hormones. Both the patient’s emotional state and hormone levels may together aggravate his/her perceived pain in the afternoon. Monitoring preoperative anxiety levels, blood pressure, and heart rate should help to identify patients at higher risk of perceived intraoperative pain.

Clinical trial registration:

Trial registration number: NCT02182921

Registration site: clinicaltrials.gov

KEYWORDS:

• Pain perception
• anxiety
• adrenalin
• cortisol
• cataract surgery

Availability of data and material

The datasets generated and/or analyzed during the present study are not publicly available (obtained from Eye and Ear, Nose, and Throat Hospital, Fudan University, Shanghai repository), but are available from the corresponding author upon reasonable request.

Competing interests: The authors declare that they have no competing interests.

Ethics approval and consent to participate

The Institutional Review Board of the Eye and ENT Hospital of Fudan University, Shanghai, China, approved this study. All procedures adhered to the Declaration of Helsinki and were conducted in accordance with the approved protocol. Written informed consent was obtained from each patient before his/her participation.

List of abbreviations

VAS	=	visual analogue scale
IOL	=	intraocular lens
ACTH	=	adrenocorticotropic hormone
ENT	=	ear, nose and throat
STAI	=	simplified State-Trait Anxiety Inventory
APAIS	=	Amsterdam Preoperative Anxiety and Information Scale
WBS	=	Wong–Baker FACES® Pain Rating Scale
SBP	=	systolic blood pressure
DBP	=	diastolic blood pressure
HR	=	heart rate
MAP	=	mean arterial pressure
ng/ml	=	nanograms per milliliter
pg/ml	=	picograms per milliliter

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This research was funded by research grants from the National Natural Science Foundation of China (81870642, 81970780, 81470613, 81100653, 81670835, and 81270989), the National Key R&D Program of China (2018YFC0116800), the Shanghai Talent Development Fund (201604), the Shanghai Youth Doctor Support Program (2014118), and the Outstanding Youth Medical Talents Program of the Shanghai Health and Family Planning Commission (2017YQ011).