Oral acetaminophen (paracetamol) for additional analgesia in phacoemulsification cataract surgery performed using topical anesthesia: Randomized double-masked placebo-controlled trial

Abstract

To evaluate the clinical analgesic efficacy of 1.0 g oral acetaminophen (paracetamol) given in addition to topical anesthesia before phacoemulsification cataract surgery. Inpatient and outpatient ophthalmology clinics, Bydgoszcz, Poland. Consecutive patients with age-related cataract having phacoemulsification under topical anesthesia (tetracaine 0.5%) were enrolled in a prospective double-blind randomized placebo-controlled study. Patients were randomly assigned to preoperative oral administration of a placebo medication or to oral administration of 1.0 g acetaminophen. The main outcome measure was intensity of pain during and after surgery. Pain intensity was measured using a 10 cm baseline visual analog scale and a discrete 5-category verbal rating scale. The study comprised 160 consecutive patients (80 in each group). Intraoperatively, the mean visual analog scale pain intensity score was 2.17 +/- 1.81 in the placebo group and 1.45 +/- 1.17 in the acetaminophen group and the mean verbal rating scale score, 1.11 +/- 0.73 and 0.67 +/- 0.66, respectively (P<.01). Postoperatively, the mean visual analog scale score for pain was 1.47 +/- 1.39 in the placebo group and 0.56 +/- 0.61 in the acetaminophen group and the mean verbal rating scale score, 0.94 +/- 0.79 and 0.28 +/- 0.41, respectively (P<.01). There was no significant difference in patient behavior during surgery and no significant adverse effects of acetaminophen use. Preoperative oral administration of acetaminophen 1.0 g was effective, convenient, safe, and cost effective in reducing intraoperative and postoperative pain in phacoemulsification performed using topical anesthesia.