Clinical Trial: Pre-Emptive Analgesia in Ano-Rectal Surgery

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: Pre-Emptive Analgesia in Ano-Rectal Surgery

Brief Summary:

The perianal region is the region around the anus. Administering a pain medication before a surgery starts is called preemptive analgesia. In some studies, this technique has been shown to be an effective way to reduce the pain that a patient experiences in the post-operative timeframe to a greater extent than would be expected simply from the pain medications alone. One theory of why this occurs suggests that the preemptive analgesia desensitizes brain and nerves to pain, thereby decreasing the response to painful stimuli, like surgery when they occur. This leads to a decrease in the amount of narcotic pain medication required after the procedure, which leads to less side effects and a quicker return to normal functioning. As perianal surgeries do not usually include a long stay in the hospital, controlling post-procedure pain is a priority.

The use of preemptive analgesia is in other types of surgeries, such as orthopedics, is well established, but as the perianal region has not been well studied, its use is not the standard of care. This type of analgesia uses a combination of medications that are already in use for post-operative and non-operative pain control and administers them orally prior to the patient undergoing general anesthesia. The side effects of the medications are the same as if they had been given after surgery or for non-surgical pain.

The concept of preemptive analgesia is established in other types of surgeries and it has solid basic science to support its use. The purpose of this randomized, double-blind, placebo controlled study is to determine if patients undergoing perianal surgeries could benefit from preemptive pain control. The primary outcome will be whether patients experience less post-operative pain. Patient post-operative consumption and latency until use of narcotic pain medication will b

Detailed Summary:

Despite advances in pain medicine, postoperative pain control remains problematic with over 5% of patients experiencing severe pain despite standard of care pain management, and is a frequently cited reason for delayed discharge in outpatient procedures [1]. In anorectal surgeries, almost all patients experience mild-to-moderate postoperative subjective pain [2], and as an example 12% of patients report severe postoperative pain during their recovery from hemorrhoidectomy surgery [3]. Control of postoperative pain is an important goal. Preemptive analgesia is a technique that involves premedicating the patient with a regimen of medications designed to target different points in the pain cascade to prevent central and peripheral sensitization to pain, also known as "wind-up" [4]. The activation of N-methyl-D-aspartate (NMDA) receptors is an identified process that occurs in central sensitization after a noxious stimulus. By pharmacologically blocking these receptors, it may be possible to prevent or suppress the degree of central sensitization, which can prevent the hyperalgesic, or exaggerated pain response, that some patients experience [5]. Peripheral sensitization is a similar concept and occurs due to noxious stimuli in the periphery, such as a surgical incision. This type of sensitization has typically been prevented with regional anesthesia and by increasing the nociceptive threshold of the neurons with different medications.

Preemptive analgesia focusing on the effect of single medications on pain control has shown promising results, however some studies appear to lend themselves to practice [6-19] better than others [20-26]. On the other hand, multimodal pain control regimens might be more promising. A search of the literature reveals that preemptive pharmacological blockade of wind up has been effectively used in both surgical and nonsurgical patients (
Sponsor: University of Vermont

Current Primary Outcome: Postoperative pain [ Time Frame: End of surgery up to 7 days postoperatively ]

Original Primary Outcome: Same as current

Current Secondary Outcome:

• Narcotic consumption [ Time Frame: End of surgery up to 7 days postoperatively ]
  Narcotic consumption will be recorded by the subject on medication diaries attached to the respective numerical rating scale. This helps to identify at which time point the patient took a narcotic. This will be compared between groups.
• Interval for rescue pain medication [ Time Frame: End of surgery up to 7 days postoperatively ]
  On the aforementioned medication diaries, the patient will record when he or she first needed break through pain medication (i.e. the narcotic prescribed) beyond the scheduled pain medicines. This will help us evaluate the interval between end of the operation and first need for breakthrough pain medication. This number will be compared between groups.
• Further pain requirements [ Time Frame: End of surgery up to 7 days postoperatively ]
  By examining the medication diaries, we will be able to evaluate if there were patients who required more than the scheduled pain medications and breakthrough narcotic. This number will be compared between groups.

Original Secondary Outcome:

• Narcotic consumption [ Time Frame: End of surgery up to 7 days postoperatively ]
  Narcotic consumption will be recorded by the subject on medication diaries attached to the respective numerical rating scale. This helps to identify at which time point the patient took a narcotic. This will be compared between groups.
• Interval for rescue pain medicaiton [ Time Frame: End of surgery up to 7 days postoperatively ]
  On the aforementioned medication diaries, the patient will record when he or she first needed break through pain medication (i.e. the narcotic prescribed) beyond the scheduled pain medicines. This will help us evaluate the interval between end of the operation and first need for breakthrough pain medication. This number will be compared between groups.
• Further pain requirements [ Time Frame: End of surgery up to 7 days postoperatively ]
  By examining the medication diaries, we will be able to evaluate if there were patients who required more than the scheduled pain medications and breakthrough narcotic. This number will be compared between groups.

Information By: University of Vermont

Dates:
Date Received: March 25, 2015
Date Started: June 2014
Date Completion: December 2016
Last Updated: May 16, 2016
Last Verified: May 2016