Effect of Intravenous Acetaminophen on Postoperative Pain in Vitrectomy: A Randomized, Double-Blind, Clinical Trial

Abstract

BackgroundNowadays, pain, nausea, and vomiting are regarded as important complications of anesthesia and surgery. The current study aimed at assessing the effect of preemptive intravenous acetaminophen on control of pain, nausea, vomiting, shivering, and drowsiness following the general anesthesia for retina and/or vitrectomy surgeries.MethodsIn a randomized, double-blind, clinical trial, 83 candidates for retina or vitrectomy eye surgery under general anesthesia were distributed into 3 groups: A) 41 patients in the control group who received 100 mL of normal saline just before the surgery and 100 mL of normal saline 20 minutes before the end of surgery; B) 21 patients in the preemptive group who received acetaminophen 15 mg/kg in 100 mL normal saline just before the surgery and 100 mL normal saline 20 minutes before the end of surgery; C) 21 patients in the preventive group who received 100 mL normal saline just before the surgery and acetaminophen 15 mg/kg in 100 mL normal saline 20 minutes before the end of surgery. Pain, nausea, vomiting, and shivering were assessed at the recovery and 2, 4, and 24 hours after the operation. Anesthesia emergence situation was assessed after arrival in the recovery room by the Richmond agitation-sedation scale (RASS) questionnaire. Blood pressure and heart rate were recorded before anesthesia induction, just after intubation, before extubation, and on discharge from the recovery room.ResultsTotal intraoperative fentanyl, duration of operation, and duration of anesthesia were not different among the studied groups. Vital signs were not statistically different among the groups at before anesthesia induction, just after intubation, before extubation, and on discharge from the recovery room. Thirty-three patients in the control group (87.8%), 11 in preemptive (52.4%), and 14 in preventive groups (66.7%) needed acetaminophen in the first 24 hours after the surgery (P value = 0.008). Pain scores measured by visual rating scale (VRS) was lower in the preemptive and preventive groups, compared with those of the control group, in the recovery (P value = 0.006), 2 hours after the surgery (P value = 0.008), and 4 hours after the surgery (P value = 0.012), but not in 24 hours after the operation (P value = 0.1).ConclusionsIntravenous acetaminophen administered as preemptive or preventive medication was effective and safe to control acute postoperative pain and analgesic request after the vitrectomy eye surgery.

Preventive Analgesia, Hemodynamic Stability, and Pain in Vitreoretinal Surgery

“…The analgesic potencies of intravenous PA using paracetamol and metamizole at a dose of 1 g proved their similar efficacies for postoperative analgesia after retinal surgery in comparison to the control group [ 32 ]. The influence of paracetamol administration for PA preoperatively or upon emergence from GA in patients undergoing PPV was observed to produce lower pain scores in both paracetamol groups compared to the control group at recovery [ 33 ]. However, an anaesthetic modality in which rescue OA was administered based on observance of the haemodynamic stability and the anaesthesiologists’ intuition was adopted, which could have markedly impaired the final rates of PIPP.…”

“…Attempts have been made to reduce the dose of intraprocedural OA via different techniques of preventive analgesia for VRS, among which the most popular are regional techniques, including the preprocedural peribulbar block (PBB) [ 22 , 23 , 24 , 25 , 26 ], retrobulbar block (RBB) [ 27 , 28 ], subtendon block [ 29 , 30 ], and topical anaesthesia (TA) [ 31 ], as well as intravenous techniques, including preprocedural infusion of paracetamol [ 32 ] or metamizole [ 33 ]. A reduction in the intraprocedural intravenous dose of OA administered in combination with GA has been proven to provide adequate analgesia postoperatively [ 28 ], with reduced incidences of PONV [ 23 , 26 ], despite potential side effects [ 3 ].…”

Adverse Events during Vitrectomy under Adequacy of Anesthesia—An Additional Report

“…Additionally, various methods of preventive analgesia (PA) for PPV, such as regional techniques [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ], and intravenous techniques with preoperative infusion of COX-3 inhibitors (paracetamol, metamizole) [ 21 , 22 ], were shown to provide adequate postoperative analgesia [ 17 ], with a fall in the rate of main adverse events [ 12 , 15 , 23 ] within the mechanism of a reduction in demand for IO.…”

The Adequacy of Anesthesia Guidance for Vitreoretinal Surgeries with Preemptive Paracetamol/Metamizole

“…In the case of paracetamol, Sadrolsadat et al investigated its influence when administered either as PA preoperatively or upon emergence from GA compared to the control group in patients undergoing PPV. They found pain scores to be lower in both the paracetamol groups, compared with the control at recovery [ 61 ].…”