Meyering Stefan H, Stringer Ryan W, Hysell Matthew K
Michigan State University, Lakeland Healthcare, Department of Emergency Medicine, St. Joseph, Michigan.
West J Emerg Med. 2017 Apr;18(3):373-381. doi: 10.5811/westjem.2016.12.29218. Epub 2017 Feb 27.
Headaches represent over three million emergency department (ED) visits per year, comprising 2.4% of all ED visits. There are many proposed methods and clinical guidelines of treating acute headache presentations. However, data on intravenous acetaminophen usage in these settings are lacking. In this study, we sought to determine the efficacy of intravenous (IV) acetaminophen as an adjunct to a standard therapy for the treatment of patients who present to the ED with a chief complaint of "headache."
We conducted a single site, randomized, double-blind, placebo-controlled trial investigating the clinical efficacy of IV acetaminophen as an adjunct to a standard therapy with prochlorperazine and diphenhydramine for the treatment of patients who present to the ED with a chief complaint of "headache" or variants thereof. (See below for variants). The primary outcome measure of the efficacy of parenteral acetaminophen as an adjunct treatment for headache in addition to a standard therapy was a threshold two-point reduction in visual analog scale (VAS) pain scores on a 1-10 level at 90 minutes. Secondary outcomes measures included assessment of decreased requirement of "rescue" pain medicines, defined as any analgesic medications outside of diphenhydramine, prochlorperazine and acetaminophen, with particular interest to potential opioid-sparing effects with parenteral acetaminophen. Additional secondary outcome measure included time to disposition from arrival in the ED.
For the acetaminophen group the initial mean pain score was 8.67, for the placebo group 8.61. At 90 minutes pain score was 2.23 for the acetaminophen group and 3.99 for placebo (p<0.01, 95% confidence interval (CI) [0.8%-16%]. Of 45 patients in each group, we observed at least a threshold two-point decrease in pain score 36/45 (80%) with acetaminophen vs. 25/45 (55%) with placebo (p <0.01) 95% CI [5%-41%], number needed to treat (NNT) = 4). Secondary outcome measure did not demonstrate a difference in length of stay (161 minutes for acetaminophen arm and 159 minutes for placebo). However, 17/45 (38%) of patients who received IV acetaminophen required rescue analgesia, opposed to 24/45 (53%) of patients in the placebo group (p=0.13) 95% CI [-5%-34%].
IV acetaminophen when used with prochlorperazine and diphenhydramine to treat acute headaches in the ED resulted in statistically significant pain reduction compared with prochlorperazine and diphenhydramine alone as measured by both threshold of lowering VAS pain score by at least two points (NNT = 4) and overall decline in VAS pain score. Further study is required to validate these results.
每年有超过300万人因头痛前往急诊科就诊，占急诊科就诊总数的2.4%。治疗急性头痛有许多推荐方法和临床指南。然而，关于在这些情况下使用静脉注射对乙酰氨基酚的数据却很缺乏。在本研究中，我们试图确定静脉注射对乙酰氨基酚作为标准疗法辅助手段治疗以“头痛”为主诉前来急诊科就诊患者的疗效。
我们进行了一项单中心、随机、双盲、安慰剂对照试验，研究静脉注射对乙酰氨基酚作为辅助手段联合使用氯丙嗪和苯海拉明标准疗法治疗以“头痛”或其变体为主诉前来急诊科就诊患者的临床疗效。（变体见下文）。除标准疗法外，静脉注射对乙酰氨基酚作为头痛辅助治疗的主要疗效指标是90分钟时视觉模拟量表（VAS）疼痛评分在1 - 10分制上降低至少2分。次要疗效指标包括评估“急救”止痛药需求的减少，“急救”止痛药定义为除苯海拉明、氯丙嗪和对乙酰氨基酚之外的任何止痛药物，特别关注静脉注射对乙酰氨基酚的潜在阿片类药物节省效应。其他次要疗效指标包括从抵达急诊科到出院的时间。
对乙酰氨基酚组初始平均疼痛评分为8.67，安慰剂组为8.61。90分钟时，对乙酰氨基酚组疼痛评分为2.23，安慰剂组为3.99（p<0.01，95%置信区间[CI][0.8%-16%]）。每组45例患者中，我们观察到对乙酰氨基酚组有36/45（80%）的患者疼痛评分至少降低了2分，而安慰剂组为25/45（55%）（p<0.01）95%CI[5%-41%]，治疗所需人数（NNT）=4。次要疗效指标未显示住院时间有差异（对乙酰氨基酚组为161分钟，安慰剂组为159分钟）。然而，接受静脉注射对乙酰氨基酚的患者中有17/45（38%）需要急救镇痛，而安慰剂组为24/45（53%）（p = 0.13）95%CI[-5%-34%]。
在急诊科，静脉注射对乙酰氨基酚与氯丙嗪和苯海拉明联合使用治疗急性头痛时，与单独使用氯丙嗪和苯海拉明相比，通过VAS疼痛评分至少降低2分的阈值（NNT = 4）和VAS疼痛评分的总体下降来衡量，疼痛减轻具有统计学意义。需要进一步研究来验证这些结果。
