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

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