Intraoperative and Post-operative Analgesic Effect of IV Acetaminophen for Sinus Surgery

A Double Blind, Randomized, Placebo-controlled Study to Investigate the Effectiveness of IV Acetominophen Administered During Functional Endoscopic Sinus Surgery in Reducing the Use of Opiates to Treat Postoperative Pain

The purpose of this study is to assess the use of IV acetaminophen (Ofirmev) as a and safe and efficacious agent in reducing post-operative pain; we hypothesize that its use will reduce post-operative pain when compared to a control group using the visual analogue score (VAS) analog pain scoring system.

Unrelieved postoperative pain may result not only in suffering and discomfort, but may also lead to multiple physiological and psychological consequences which can contribute to adverse perioperative outcomes. Inadequate perioperative analgesia can potentially contribute to a higher incidence of myocardial ischemia. Additionally, the use of opioids has been associated with major side effects that can include impaired wound healing and delayed gastrointestinal (GI) motility that results in prolonged postoperative ileus.

Intravenous acetyl-para-aminophenol (APAP, also known as acetaminophen) is considered as the non-opioid analgesic of choice to treat postoperative mild and moderate pain, and has been demonstrated in several randomized trials to be both safe and effective at reducing acute post-operative pain in both children and adults. Furthermore, in the treatment of severe pain, it can reduce the need for opioid-analgesics while exhibiting a relatively limited side effect profile when compared to opioids and nonsteroidal anti-inflammatory drugs.

Chronic rhinosinusitis (CRS) describes a group of disorders characterized by inflammation of the nasal mucosa and/or paranasal sinuses for at least 12 consecutive weeks. In the United States, CRS affects approximately 30 million people, and represents 2% of the primary diagnoses in physician office visits, resulting in an estimated 200,000 sinus procedures annually. Patients suffering from CRS that is refractory to medical management complain of symptoms that include fatigue, headache, nasal drainage, facial pain and pressure, and decreased sense of smell. Functional endoscopic sinus surgery (FESS) represents a surgical approach to treating CRS that is unresponsive to medical management. Outcomes studies have identified FESS as efficacious at reducing the majority of symptoms related to CRS. Despite this, pain associated with CRS remains a significant co-morbidity that often is resistant to both medical and surgical management. Reducing the incidence and severity of acute post-operative pain is paramount to reducing the development of chronic pain that may exacerbate a patient's existing pain. The use of pre- and intra- operative IV acetaminophen thus serves as a unique pain management modality in this setting, as it has the potential for reducing post-operative complications and pain, with the additional benefit of minimal intraoperative bleeding, an undesirable complication often associated with FESS and with the use of non-steroidal anti-inflammatory drugs (NSAIDs).

The use of IV acetaminophen in ear, nose, and throat (ENT) surgery is not a novel endeavor. Indeed, studies have demonstrated the efficacy and safety of IV acetaminophen for use in tonsillectomy and FESS. We wish to provide a more comprehensive analysis of pain management in the setting of FESS in the following ways :

1. by administering IV acetaminophen perioperatively (before start of surgery, and after surgery completion;
2. by employing a pain score of 4 (whereas other studies use 3) as a cutoff for breakthrough pain; and,
3. by addressing novel outcomes including patient sedation and patient satisfaction, in addition to opioid analgesic use.

In our institution, we have completed a preliminary pilot study exploring the use of intravenous anesthesia which included acetaminophen during bilateral endoscopic sinus surgery. Secondary outcomes measured during the study included:

1. Pain
2. Rescue analgesic use
3. Nausea/Vomiting
4. Time spent in recovery
5. Successful discharge from the PACU and the Hospital

Our pilot data has reaffirmed that the procedure is overall benign, with few associated risks and adverse events. Of note, none of the patients in our preliminary study required admission to the hospital after surgery for further observation as a result of uncontrolled pain or nausea. Based on this experience, we would like to explore the efficacy of intravenous acetaminophen (Ofirmev), a non opioid/non steroidal analgesic, in endoscopic sinus surgery.

Inclusion criteria:

1. Patients undergoing surgical management for CRS (with or without polyps)
2. Operating time must be at least 2 hours in duration.
3. Number of sinuses involved must be 3 or greater

Exclusion criteria:

1. History of hypersensitivity to acetaminophen
2. End stage renal disease
3. End stage liver disease
4. History of chronic pain, or use of opioid medication in the previous two weeks
5. Severe depression or anxiety
6. Use of gabapentin or any other pain modulator
7. History of acute sinusitis or mucocele
8. History of seizures
9. Known or suspected history of alcohol or drug abuse
10. Known or suspected history of morphine intolerance