Critique of Systematic Review

According to the systematic review covered by Apfel, Turan, Souza, Pergolizzi & Hornuss, 2013 there is a significant reduction in postoperative nausea and vomiting and opioid use when using intravenous acetaminophen. The reviewers used Medline and Cochrane databases to conduct their search along with a hand search of abstracts to identify randomized-controlled trials using intravenous acetaminophen. The review was to determine if the acetaminophen was going to have a significant decline in nausea and vomiting following surgical procedures as this is a large concern for patients following their procedures.While the studies were testing for postoperative nausea and vomiting what they were able to find was also better pain control in some instances.

But with this systematic review it was clear that the studies included various different outcomes depending on a multitude of scenarios.By using randomized-controlled trials for the articles being researched in the systematic review they were utilized the highest level of evidence. The group ensured that the study was conducted in compliance with the preferred reporting items for systematic reviews and meta-analysis, or prisma.After the initial search revealed 217 references they began to exclude various references which left them with a total of 30 papers.

Included in these 30 papers were a total of 2364 patients total with 1223 being the acetaminophen group and 1441 in the placebo group. The research articles all included reports of nausea or vomiting. The hard part was finding a patient that experienced one without the other as usually patients experience the symptoms together. Most do not experience vomiting without feeling nausea they run in conjunction with each other. The results of the studies were a little confusing to say the least.

What was started as a study to show that there were less reports of postoperative nausea and vomiting ended up being a study that showed that the two usually ran hand in hand as you cannot have vomiting really without having nausea but on the other hand you can have nausea without vomiting so it was a little hard to show a difference in the two. But also that it not only mattered when they received the acetaminophen that it also seemed to help with vomiting more if just one dose was given than if additional doses were also given so one dose worked the best.And while they were not really assessing for pain control it was determined that there was less use of additional opioids if the patient received acetaminophen. The study has so many ands, buts and in additions to. It seemed like the results were all over the place making it hard to determine if the initial question truly was answered. Here is one example to show how things seemed to contradict each other Number needed to treat for i.

v. acetaminophen was 12. 3 (7. 6–32. 3) for nausea and 14. 2 (8.

3– 50. 8) for vomiting.Sensitivity analysis revealed that i. v. acetaminophen reduced nausea (0. 63, 0.

54–0. 75) and vomiting (0. 42, 0. 31– 0. 56) in investigator-initiated trials, but did not reduce nausea (1. 12, 0.

85–1. 48) and even increased vomiting (1. 41, 1. 02–1. 96) in industry- sponsored clinical trials.A closer look showed that i.

v. acetaminophen was generally started prophylactically in investigator-initiated trials, while it was generally given the day following surgery in industry-sponsored registration trials. (Apfel et al, 2013). When you read through the entire review it appears that the results basically end in the same result but getting to the results were started in various different manners.According to Apfel et al, 2013, postoperative nausea and vomiting occurs in approximately 30% of all patients that undergo general anesthesia with the main triggers being known to be inhalational anesthetics and/or opioids. Although they were able to find various studies due to the small size of the studies the review was unable to detect if there were any publication bias.

They felt that a large more well-designed randomized-controlled trial would need to be conducted to confirm the findings (Apfel et al. , 2013).Of the studies included most of the studies did not show actual reported postoperative nausea and vomiting but after the study most were able to show that there was a decrease in opioid use when using the intravenous acetaminophen therefore decreasing other adverse effects that would be noted with harder opioid use. The studies did show that if intravenous acetaminophen was given preoperative and during the surgical procedure that the antiemetic effects were increased significantly instead of waiting to treat postoperatively.And by decreasing the postoperative nausea and vomiting they noticed a decrease in reports of pain.

In summary, the study was able to show that using intravenous acetaminophen was effective in reducing postoperative nausea and vomiting but more so when only used as one prophylactic dose and was comparable to other anti-emetics currently being used along with also having an effect of decreased pain with a decrease in opioid consumption.Today the focus on patient pain relief is a major focus but you want to find a pain control with the least amount of adverse effects as possible. If there is a significant decrease in pain with using something as safe as intravenous acetaminophen rather than say more significant opioids then there would be many less adverse side effects such as respiratory depression.