Multi-Drug Analgesia vs. Standard Solution for Anal Surgery

The primary aim is to test the magnitude and duration of analgesia provided by single dose multi-drug analgesia administered for perianal block, and compare with standard solution (Marcaine \& Lidocaine in 1:1 mixture - Total 60 ml), at post-operative period and also to compare with the standard solution including their respective post-operative opioid or non-opioid oral analgesic requirement. Local anesthesia via a perianal block using multi-drug analgesia or standard solution will be compared using the Numeric pain rating scale on Post-operative day 1, 3 and during follow up visit on day 7. The investigators hope to find a better control of post-operative analgesia which will lead to better functional outcomes. Possible decrease consumption of opioids in the post-operative period will perhaps decrease the cost and chances of addiction and will increase patient comfort and compliance.

Post-operative analgesia after anorectal surgery still poses a significant problem. Technical or operator dependent factors have been proposed for causing severe pain post operatively. Many factors such as height of anastomosis, incorporation of smooth muscle, size of doughnut, and inclusion of squamous epithelium were considered to cause pain specially after hemorrhoidectomy. However, in spite of standardizing the techniques, patients still experience moderate to severe pain after anorectal surgery. Effective post-surgical pain control is critical to patient recovery, and can contribute to improved healing, faster patient mobilization, reduced hospital stays and health care costs. Effective multimodal techniques have been devised to maximize pain relief, lower the risk of adverse events, and improve patient outcomes. These techniques (wound infiltration with local anesthetic being most common) is short lived, maximum up to 12 hours. Post-operative pain usually lasts for 72 hours and thus the systemic opioids remain the mainstay pain control post-operatively. Although effective analgesics, they are associated with unwanted and potentially adverse events, such as nausea, vomiting, pruritus, sedation, cognitive impairment, urinary retention, sleep disturbances, and respiratory depression. Also, narcotic addiction remains a concern for surgical patients. Some patients would like to have effective analgesia and thus also avoid narcotics.Multi-drug analgesic combinations are used in orthopedic surgery (Ropivacaine, Ketorolac, and Morphine, with adrenaline) and during hemorrhoidectomy (extended-release liposome Bupivacaine) which showed decrease in post-operative analgesia requirement. However, no studies that used multi-drug analgesia show any effect on the pain medication consumption after discharge for ambulatory surgery. The investigators have designed a novel multi-drug anesthetic formulation to achieve long-acting postoperative analgesia with single-dose administration intra-operative via perianal block and wound infiltration.

Eligibility Criteria:
Inclusion Criteria:

* Men and nonpregnant women aged 18 years or older scheduled to undergo anorectal procedures
* Female patients must be postmenopausal, surgically sterile, or willing to use acceptable means of contraception for at least 30 days after surgery.
* Patients will be required to have an Americal society of anesthesia physical status classification of 1, 2, or 3.

Exclusion Criteria:

* Patients with concurrent or recent medical conditions that might interfere with study participation, including history of hepatitis, alcohol/substance abuse, uncontrolled psychiatric disorders, known allergy, or contraindication to amide-type local anesthetics, opioids, or propofol.
* Patients who are participating in another study involving an investigational medication within the prior 30 days, or were taking analgesics (ie, non- steroidal anti-inflammatory drugs, acetaminophen, or opioids), antidepressants, or glucocorticoids within the 3 days before surgery.