Efficacy of Intrauterine Lidocaine Instillation in Reducing Pain during Endometrial Biopsy by Novak

Abnormal uterine bleeding in women aged 35 years or over is an important clinical sign of many gynecological conditions. The diagnoses of these conditions require the pathological report of the endometrial tissue. Outpatient-based endometrial biopsy is an excellent option compared to standard fractional uterine curettage or hysteroscopy with endometrial biopsy in providing a definite diagnosis for abnormal uterine bleeding as it is less painful and does not require high potency anesthesia. This study evaluates the effect of intrauterine lidocaine on the patient's pain score during endometrial biopsy by the Novak curette. We included patients aged 35 years or more who had abnormal uterine bleeding between December 2016 and March 2018. The study was conducted at Thammasat University Hospital, Pathum Thani, Thailand. 250 patients were randomly allocated to either receive intrauterine lidocaine (study group) or normal saline (control group). Assessment of pain severity was evaluated using a visual analogue scale (VAS) score at 6 time-points, namely, before performing the procedure, when grasping the cervix by the tenaculum, during the intrauterine instillation of lidocaine or normal saline, during the uterine curettage, and then 15 minutes and 2 hours after the procedure. This study showed that there was significant pain reduction in patients who received intrauterine instillation of lidocaine compared to placebo, during uterine curettage, as well as 15 minutes and 2 hours after procedure (p<0.0001). Patient satisfaction was not significantly different between the two groups, while physician satisfaction significantly improved in the lidocaine group. Serious complications were not found during this study. (This research project had been approved for registration at Thai Clinical Trials Registry. TCTR identification number is TCTR20161031003.)