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34 Randomized, Prospective, Double-Blind, Placebo-Controlled Trial of Effect of Nitroglycerin Ointment on Pain After Hemorrhoidectomy [2001년 8월 DCR] 2011-11-17 3458
 
Harry J. Wasvary, M.D., Jon Hain, M.D., Michele Mosed-Vogel, M.D., Philip Bendick, Ph.D., Donald C. Barkel, M.D., Steven N. Klein, M.D.
 
From the Department of Colon and Rectal Surgery, William Beaumont Hospital, Royal Oak, Michigan
 
PURPOSE: Fissure-in-ano is characterized by pain, bleeding, and internal anal sphincter hypertonicity. Spasm of the internal sphincter also plays a role in hemorrhoidal disease and may- be a source of anal pain after hemorrhoid surgery. Inducing sphincter relaxation with a nitroglycerin ointment has shown promise in healing anal fissures and relieving symptoms of pain. Our study attempts to test the hypothesis that topical nitroglycerin applied to the perianal region is beneficial in reducing pain after hemorthoidectomy.
METHODS: After hemorrhoidectomy 39 patients were randomly assigned to receive 0.2 percent nitroglycerin ointment (n = 19) or placebo (n = 20). Ointments were applied to the perianal region three times daily for seven days. Patients were prescribed hydrocodone bitartrate to take as needed.
Visual analog scales were used to measure postoperative pain intensity and ointment benefits. Patients completed questionnaires to record medication morbidity and number of prescribed or nonprescribed medications taken.
RESULTS: Patients using nitroglycerin had less pain and greater benefit from ointment than those did in the placebo group, but differences were not significant. Narcotic use was higher in the placebo group when considered on a daily basis, but was statistically significant on the second postoperative day only (P < 0.05). Morbidity from ointment application was significantly higher in the nitroglycerin group (P
< 0.002) and included a headache in 8 of 19 patients. Nonsteroidal anti-inflammatory drugs and acetaminophen were not prescribed, but were taken more frequently in nitroglycerin patients (P < 0.0003).
CONCLUSION: Perianal application of 0.2 percent nitroglycerin ointment after hemorrhoidectomy
significantly reduced narcotic requirements on the second postoperative day. Headaches and a subsequent need for nonnarcotic medications may limit benefits of nitroglycerin.
 
Hemorrhoidectomy commonly leads to postoperative pain, which may cause anxiety in patients and doctors. When residual pain after hemorrhoidectomy can be managed adequately, the operation can be performed in an outpatient setting. This makes it a viable and economical procedure. Hypertonicity of the internal anal sphincter (IAS) is felt to play a role in the cause of hemorrhoidal and anal fissure pain. Spasm of the IAS may also be a source of pain after anal surgery induding hemorrhoidectomy. Recent evidence suggests that nitric oxide (NO) is an inhibitory neurotransmitter in the IAS. Organic nitrates, such as nitroglycerin (NTG) are degraded by cellular metabolism, liberating NO. NTG applied topically to the anus has been shown to cause a lowering of IAS pressure in clinical trials. Therefore, it seems likely that reducing IAS hypertonia could relieve postoperative pain associated with the hemorrhoidectomy procedure. In this study glyceryt trinitrate was used as an exogenous NO donor.
 
DISCUSSION
Hypertonia of the IAS has been associated with anal fissure, Traditional therapy of lateral internal sphincterotomy has been effective in muscle relaxation, pain relief, and fissure healing. Introduction of topical NTG to create a "reversible chemical sphincterotomy" was initially met with great enthusiasm, because it avoided permanent alterations in continence associated with surgical sphincterotomy. Healing rates among trials are conflicting, but pain experienced with anal fissure is substantially reduced after the application of NTG ointment, often despite the persistence of the fissure. Surgical sphincterotomy has also been used to decrease pain after hemorrhoidectomy and led us to postulate that NTG could play a similar role in overcoming postoperative spasm.
 
Numerous publications investigating the benefits of NTG therapy for anal fissure were helpful in creating this trial. Because there is no standard dose delivery system currently available, the amount of ointment
used has been quite variable. Our patients were given a measuring spoon that limited dosing to 1 g.
Ointment was administered with a cotton-tipped swab to avoid unnecessary absorption experienced when an ungloved finger is used for application. The ideal concentration of NTG to reduce anal resting pressure is unresolved, but the use of a 0.2 percent preparation is generally considered adequate. The duration of action of NTG may range from 8 to 12 hours and seemed to be less than this in one study. TO account for this variability, patients administered ointment every six hours while awake, because sleeping is associated with a natural reduction in anal pressure relative to ambulatory values. A better understanding of the pharmakinetics of NTG is necessary to control the substantial incidence of side effects created when topical nitrates are administered. Transient headaches are a significant problem, especially with higher drug concentrations. Our incidence of 53 percent is somewhat higher than other reports, yet no patient felt the headache warranted discontinuation of the ointment.
 
hemorrhoidectomy pain, our results bring up several issues to consider. First, a visual analog scale documented the pain experienced from the perspective of the patient. On each of the seven postoperative days, perceived pain was less in those patients applying NTG; however, these differences were not significant. Similar results were obtained when perceived benefit of the ointment was measured.
 
Pain perception was also measured indirectly by recording the number of Vicodin ® tablets required and is possibly more objective than using a visual analog scale. The visual analog scale attempts to equate subjective feedback with objective data and is thus subject to criticism. No differences existed between groups when narcotic requirements were subjected to repeated measures analysis, but Vicodin ® usage in NTG patients was significantly less on the second postoperative day when daily comparisons were tabulated (Table 3). It is interesting that compliance with NTG ointment was also greatest on the second postoperative day (Fig. 6).
 
Despite less Vicodin ® use, patients using NTG had a significantly higher need for nonnarcotic medications (Tylenot ® and blotrin ®) than patients taking placebo (85 vs. 22 percent, respectively; P = 0.001), and this may have influenced pain scores. The sample size in each group is small, and identifying a variable to account for a patient's preference for additional or alternative analgesics is difficult. However, all eight patients who experienced headaches in the NTG group reported nonnarcotic
usage, and one might postulate that NTG may be effective for reducing anal pain and thus decrease narcotic use, but it also creates a need for acetaminophen and nonsteroid drugs to control the NTG-induced headache.
 
Thus, we conclude with the same question others have asked when using NTG for perianal pain--is
reducing pain in the anus worth the headache? NTG may relieve pain when patients are compliant with its application, as noted on the second postoperative day, but compliance and benefits are limited by headaches and the need for other analgesics. At this time I feel more work in this area needs to be done before this approach becomes standard first-line therapy for hemorrhoidectomy pain control. Yet in the patient who is unable to achieve adequate pain relief by standard methods of analgesia, NTG may be beneficial when well informed of its side effects.