Intravenous Versus Oral Acetaminophen in Primary Total Hip Arthroplasty

• Sponsor: Duke University (Other)
• Overall Status: Completed
• CT.gov ID: NCT02839876
• Collaborator: (none)
• Enrollment: 81
• Location: 1
• Arms: 2
• Actual Duration (Months): 19.6
• Patients Per Site Per Month: 4.1

Study Details

Study Description

Brief Summary

The purpose of this study is to determine if intravenous acetaminophen is superior to oral acetaminophen when used as part of a multimodal pathway for primary total hip arthroplasty.

Condition or Disease	Intervention/Treatment	Phase
Osteoarthritis; Acetaminophen; Arthroplasty, Hip Replacement	Drug: Intravenous acetaminophen; Drug: Oral acetaminophen	Phase 4

Detailed Description

This is a single center, prospective, randomized controlled study. 60 subjects will be recruited (see #6 Recruitment and Compensation below). On the day of surgery, subjects will be randomized to receive either the study intervention (intravenous acetaminophen and placebo tablets) or the control intervention (intravenous saline and active acetaminophen tablets). The Investigational Drug Service will prepare each intervention package, which will include one intravenous and one oral medication dose. Only one of these routes will be active (determined by randomization). Subjects will receive doses of both an intravenous and oral study drug every 6 hours in order to maintain blinding, and will receive a total of 4 doses of each (at 0, 6, 12 and 18 hours). The dose of acetaminophen in all cases will be 1000 mg. The volume of intravenous acetaminophen (and saline) will be 100 mL. The oral dose will consist of two (2) tablets of 500 mg each (or two matching placebo tablets).

All subjects will receive a standardized anesthetic regimen for total hip arthroplasty, as follows:

1. Preoperative phase

Subjects will receive the following preoperative multimodal drugs:

• Pregabalin 75 mg PO

• Celecoxib 200 mg PO

• The interventional drugs, both IV and PO . The time that these drugs are administered will be recorded as time zero. Patients will then receive a spinal anesthetic with 12.5 mg of isobaric bupivacaine. No peripheral nerve blocks will be performed.

1. Intraoperative phase All subjects will be receive propofol infusion beginning at 50 mg/kg/min and titrated to a Richmond Agitation-Sedation Scale score of -1 to -3 (drowsy to moderate sedation). Dexamethasone 10 mg IV and ketamine 0.25 mg/kg IV up to 40 mg total will be administered as part of the standard multimodal regimen. If required, subjects may receive fentanyl 25 mcg IV as needed to treat discomfort. No joint infiltration will be performed by the surgeon.

2. Postoperative phase In the Post-Anesthesia Care Unit (PACU), subjects will have an intravenous patient-controlled analgesia (IVPCA) device connected and loading doses of hydromorphone administered by the PACU nurse as necessary (0.2 mg q 8 min prn).

On the floor, subjects will receive:

• Pregabalin 75 mg PO BID until discharge

• Celecoxib 200 mg PO BID until discharge

• Dexamethasone 10 mg IV x 1 on postoperative day 1 (24 hours after the first dose)

• Intravenous patient-controlled analgesia (IVPCA) with hydromorphone (0.2 mg q 8 min).

The remaining 3 intervention packages (IV and PO) will be administered at 6, 12 and 18 hours following the first dose. At time point 24 hours (i.e. the fifth dose of acetaminophen), all subjects will begin to receive 975 mg of oral acetaminophen, continuing every six hours until discharge.

Study Design

• Study Type: Interventional
• Actual Enrollment: 81 participants
• Allocation: Randomized
• Intervention Model: Parallel Assignment
• Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
• Primary Purpose: Treatment
• Official Title: Comparison of Multimodal Analgesic Regimen With Intravenous Acetaminophen to Standard Oral Multimodal Therapy in Primary Total Hip Arthroplasty: A Randomized Controlled Double Blind Trial
• Actual Study Start Date: Mar 14, 2017
• Actual Primary Completion Date: Oct 2, 2018
• Actual Study Completion Date: Oct 31, 2018

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Intravenous acetaminophen Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo.	Drug: Intravenous acetaminophen; Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.; Other Names: Ofirmev
Active Comparator: Oral acetaminophen Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo.	Drug: Oral acetaminophen; Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.

Outcome Measures

Primary Outcome Measures

1. 24 Hour Opioid Consumption [24 hours]

   Cumulative dose of hydromorphone consumed in the first 24 hours postoperatively

Secondary Outcome Measures

1. Opioid Consumption (Other) [0-48 hours]

   morphine equivalent units of intravenous and oral opioids

2. Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (Preoperatively) [preoperatively]

   Pain scores (using NRS-11 scale) with active range of motion of the hip. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).

3. Pain Scores, as Measured by the 11-point Numeric Rating Scale (NRS-11) (1 Hour After Arrival to PACU) [1 hour after arrival to PACU]

   Pain scores (using NRS-11 scale) at rest. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).

4. Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (8 Hours) [8 hours]

   Pain scores (using NRS-11 scale) at rest. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).

5. Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (24 Hours) [24 hours]

   Pain scores (using NRS-11 scale) at rest. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).

6. Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (36 Hours) [36 hours]

   Pain scores (using NRS-11 scale) at rest. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).

7. Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (48 Hours) [48 hours]

   Pain scores (using NRS-11 scale) at rest. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).

8. Subject Satisfaction at 24 Hours [24 hours]

   Overall subject satisfaction with hospital experience at the 24 hour time point using a simple 11-point Likert scale to quantify global satisfaction. 0=completely unsatisfied, 10=completely satisfied.

9. Subject Satisfaction at 48 Hours (48 Hours) [48 hours]

   Overall subject satisfaction with hospital experience at the 48 hour time point using a simple 11-point Likert scale to quantify global satisfaction. 0=completely unsatisfied, 10=completely satisfied.

10. Straight Leg Raise [Postoperative day 1]

    Number of participants who are able to complete the active straight leg test. The subject rests supine and is asked to lift his/her operative lower limb (with knee extended) until the ankle is 20 cm from level. If the subject can do this, the test is positive.

11. Heel Slide Test [Postoperative day 1]

    Number of participants who are able to complete the heel-slide test. The subject rests supine and is asked to place the heel of his/her operative side on the contralateral knee, then slide the heel down to the ankle and back in one continuous motion. If the subject can do this, the test is positive. If the subject cannot do this in one motion, or if pain or other factors prevent the test from being performed, the test is negative.

12. Number of Participants Able to Complete the Supine to Sit Test [Postoperative day 1]

    Number of participants able to go from supine to a sitting position independently.

13. Self-paced Walk Test [Postoperative day 1]

    Time taken to walk down a hallway 20 m at a safe and quick pace, turn around and return to starting point.

14. Number of Participants With Opioid-related Adverse Events [0-72 hours]

    Incidence of respiratory desaturation events, nausea, vomiting, pruritis, ileus, and constipation

15. Analgesic Consumption as Measured by Patient Diary [day 30]

    morphine equivalent units of oral opioids and other non-opioids

16. Worst Pain (Day 30) [day 30]

    Participants are asked to rate their WORST pain on POSTOPERATIVE DAY 30 on an 11-point scale (0=no pain at all, 10=worst imaginable pain).

17. Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (Preoperatively) [preoperatively]

    Pain scores (using NRS-11 scale) at rest. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).

18. Pain Scores, as Measured by the 11-point Numeric Rating Scale (NRS-11) (1 Hour After Arrival to PACU) [1 hour after arrival to PACU]

    Pain scores (using NRS-11 scale) at with active range of motion of the hip. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).

19. Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (8 Hours) [8 hours]

    Pain scores (using NRS-11 scale) with active range of motion of the hip. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).

20. Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (24 Hours) [24 hours]

    Pain scores (using NRS-11 scale) with active range of motion of the hip. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).

21. Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (36 Hours) [36 hours]

    Pain scores (using NRS-11 scale) with active range of motion of the hip. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).

22. Subject Satisfaction at 48 Hours [48 hours]

    Overall subject satisfaction with hospital experience at the 48 hour time point using a simple 11-point Likert scale to quantify global satisfaction. 0=completely unsatisfied, 10=completely satisfied.

23. Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (48 Hours) [48 hours]

    Pain scores (using NRS-11 scale) with active range of motion of the hip. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).

Other Outcome Measures

1. Hospital Length of Stay [0-72 hours]

   Time to both discharge readiness and to actual discharge

2. Overall Hospital Admission Costs [0-72 hours]

   difference in total hospital admission cost between groups

3. Pharmacy-related Costs [0-72 hours]

   difference in pharmacy-related cost between groups

4. Costs Related to Opioid-related Adverse Events [0-72 hours]

   difference in cost related to treatment of opioid-related adverse events (nausea, vomiting, pruritis, constipation, respiratory depression, dizziness) between groups

5. Cost Associated With Nursing Interventions and Drugs to Treat Opioid-related Adverse Events [0-72 hours]

   mean cost (per patient) related to nursing care of opioid-related adverse events (nausea, vomiting, pruritis, constipation, respiratory depression, dizziness) in $USD

Eligibility Criteria

Criteria

• Ages Eligible for Study: 56 Years to 85 Years
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Inclusion Criteria:

• Patients scheduled for elective, primary total hip replacement for osteoarthritis

• American Society of Anesthesiologists (ASA) Physical Classification I-III

• Weight 50 kg or greater

• Body mass index 18-40 kg/m2

Exclusion Criteria:

• Inability to consent to study

• Inability to speak English

• Pregnancy

• Weight <50 kg

• Revision hip replacement or emergency surgery

• Contraindications to spinal anesthesia: coagulopathy or bleeding diathesis, local infection, allergy to local anesthetics

• Allergies/intolerances/contraindications to any of the multimodal agents: acetaminophen, pregabalin, celecoxib, ketamine, or dexamethasone

• Chronic pain from a separate source other than operative hip

• Daily opioid equivalent use of 30 mg of morphine or greater at time of consent

• History of heart failure

• History of drug or alcohol abuse

• Rheumatoid arthritis

• Uncontrolled anxiety, schizophrenia or other psychiatric disorder that, in the opinion of the investigator, may interfere with the study assessments

• Chronic malnutrition, renal or liver impairment

• Hypersensitivity to acetaminophen or any of its excipients

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Duke University Hospital	Durham	North Carolina	United States	27710

Sponsors and Collaborators

• Duke University

Investigators

None specified.

Study Documents (Full-Text)

• Study Protocol and Statistical Analysis Plan - Dec 6, 2017

More Information

Publications

None provided.

• Responsible Party: Duke University
• ClinicalTrials.gov Identifier: NCT02839876
• Other Study ID Numbers: Pro00072610
• First Posted: Jul 21, 2016
• Last Update Posted: Mar 9, 2021
• Last Verified: Mar 1, 2021

• Individual Participant Data (IPD) Sharing Statement: No
• Plan to Share IPD: No
• Studies a U.S. FDA-regulated Drug Product: Yes
• Studies a U.S. FDA-regulated Device Product: No
• Product Manufactured in and Exported from the U.S.: No
• Additional relevant MeSH terms: Osteoarthritis; Acetaminophen

Study Results

Participant Flow

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Period Title: Overall Study
STARTED	41	40
COMPLETED	31	29
NOT COMPLETED	10	11

Baseline Characteristics

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen	Total
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.	Total of all reporting groups
Overall Participants	31	29	60
Age (years) [Mean (Inter-Quartile Range) ]
Mean (Inter-Quartile Range) [years]	65	63	64.5
Sex: Female, Male (Count of Participants)
Female	10 32.3%	16 55.2%	26 43.3%
Male	21 67.7%	13 44.8%	34 56.7%
Race (NIH/OMB) (Count of Participants)
American Indian or Alaska Native	1 3.2%	0 0%	1 1.7%
Asian	0 0%	0 0%	0 0%
Native Hawaiian or Other Pacific Islander	0 0%	0 0%	0 0%
Black or African American	1 3.2%	5 17.2%	6 10%
White	23 74.2%	23 79.3%	46 76.7%
More than one race	5 16.1%	1 3.4%	6 10%
Unknown or Not Reported	1 3.2%	0 0%	1 1.7%
Region of Enrollment (participants) [Number]
United States	31 100%	29 100%	60 100%
ASA Physical Classification (Count of Participants)
ASA I	1 3.2%	0 0%	1 1.7%
ASA II	17 54.8%	19 65.5%	36 60%
ASA III	13 41.9%	10 34.5%	23 38.3%
Weight (kilograms) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [kilograms]	87.99 (21.90)	87.25 (18.79)	87.63 (20.29)

Outcome Measures

1. Primary Outcome

Title	24 Hour Opioid Consumption
Description	Cumulative dose of hydromorphone consumed in the first 24 hours postoperatively
Time Frame	24 hours

Outcome Measure Data

Analysis Population Description

Only completed participants are included.

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [morphine milliequivalent]	3.0	3.4

2. Secondary Outcome

Title	Opioid Consumption (Other)
Description	morphine equivalent units of intravenous and oral opioids
Time Frame	0-48 hours

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [morphine milliequivalent]	6.2	6.8

3. Secondary Outcome

Title	Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (Preoperatively)
Description	Pain scores (using NRS-11 scale) with active range of motion of the hip. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).
Time Frame	preoperatively

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [score on a scale]	7.0	7.0

4. Secondary Outcome

Title	Pain Scores, as Measured by the 11-point Numeric Rating Scale (NRS-11) (1 Hour After Arrival to PACU)
Description	Pain scores (using NRS-11 scale) at rest. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).
Time Frame	1 hour after arrival to PACU

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [score on a scale]	1.0	1.0

5. Secondary Outcome

Title	Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (8 Hours)
Description	Pain scores (using NRS-11 scale) at rest. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).
Time Frame	8 hours

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [score on a scale]	2.0	3.0

6. Secondary Outcome

Title	Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (24 Hours)
Description	Pain scores (using NRS-11 scale) at rest. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).
Time Frame	24 hours

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [score on a scale]	2.0	1.0

7. Secondary Outcome

Title	Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (36 Hours)
Description	Pain scores (using NRS-11 scale) at rest. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).
Time Frame	36 hours

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [score on a scale]	3.0	2.0

8. Secondary Outcome

Title	Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (48 Hours)
Description	Pain scores (using NRS-11 scale) at rest. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).
Time Frame	48 hours

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [score on a scale]	2.0	2.0

9. Secondary Outcome

Title	Subject Satisfaction at 24 Hours
Description	Overall subject satisfaction with hospital experience at the 24 hour time point using a simple 11-point Likert scale to quantify global satisfaction. 0=completely unsatisfied, 10=completely satisfied.
Time Frame	24 hours

Outcome Measure Data

Analysis Population Description

Only completed participants are included.

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [score on a scale]	9	9

10. Secondary Outcome

Title	Subject Satisfaction at 48 Hours (48 Hours)
Description	Overall subject satisfaction with hospital experience at the 48 hour time point using a simple 11-point Likert scale to quantify global satisfaction. 0=completely unsatisfied, 10=completely satisfied.
Time Frame	48 hours

Outcome Measure Data

Analysis Population Description

Only completed participants are included.

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [score on a scale]	9	9

11. Secondary Outcome

Title	Straight Leg Raise
Description	Number of participants who are able to complete the active straight leg test. The subject rests supine and is asked to lift his/her operative lower limb (with knee extended) until the ankle is 20 cm from level. If the subject can do this, the test is positive.
Time Frame	Postoperative day 1

Outcome Measure Data

Analysis Population Description

Only completed participants are included.

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Count of Participants [Participants]	16 51.6%	11 37.9%

12. Secondary Outcome

Title	Heel Slide Test
Description	Number of participants who are able to complete the heel-slide test. The subject rests supine and is asked to place the heel of his/her operative side on the contralateral knee, then slide the heel down to the ankle and back in one continuous motion. If the subject can do this, the test is positive. If the subject cannot do this in one motion, or if pain or other factors prevent the test from being performed, the test is negative.
Time Frame	Postoperative day 1

Outcome Measure Data

Analysis Population Description

Only completed participants are included.

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Count of Participants [Participants]	25 80.6%	16 55.2%

13. Secondary Outcome

Title	Number of Participants Able to Complete the Supine to Sit Test
Description	Number of participants able to go from supine to a sitting position independently.
Time Frame	Postoperative day 1

Outcome Measure Data

Analysis Population Description

Only completed participants are included.

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Count of Participants [Participants]	10 32.3%	6 20.7%

14. Secondary Outcome

Title	Self-paced Walk Test
Description	Time taken to walk down a hallway 20 m at a safe and quick pace, turn around and return to starting point.
Time Frame	Postoperative day 1

Outcome Measure Data

Analysis Population Description

Only completed participants are included.

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Mean (Inter-Quartile Range) [seconds]	86	63

15. Secondary Outcome

Title	Number of Participants With Opioid-related Adverse Events
Description	Incidence of respiratory desaturation events, nausea, vomiting, pruritis, ileus, and constipation
Time Frame	0-72 hours

Outcome Measure Data

Analysis Population Description

Only completed participants are included.

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Number [participants]	15 48.4%	7 24.1%

16. Secondary Outcome

Title	Analgesic Consumption as Measured by Patient Diary
Description	morphine equivalent units of oral opioids and other non-opioids
Time Frame	day 30

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [mg]	0	0

17. Secondary Outcome

Title	Worst Pain (Day 30)
Description	Participants are asked to rate their WORST pain on POSTOPERATIVE DAY 30 on an 11-point scale (0=no pain at all, 10=worst imaginable pain).
Time Frame	day 30

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [score on a scale]	1.0	0

18. Secondary Outcome

Title	Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (Preoperatively)
Description	Pain scores (using NRS-11 scale) at rest. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).
Time Frame	preoperatively

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [score on a scale]	1.0	2.0

19. Secondary Outcome

Title	Pain Scores, as Measured by the 11-point Numeric Rating Scale (NRS-11) (1 Hour After Arrival to PACU)
Description	Pain scores (using NRS-11 scale) at with active range of motion of the hip. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).
Time Frame	1 hour after arrival to PACU

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [score on a scale]	2.0	2.0

20. Secondary Outcome

Title	Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (8 Hours)
Description	Pain scores (using NRS-11 scale) with active range of motion of the hip. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).
Time Frame	8 hours

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [score on a scale]	3.0	5.5

21. Secondary Outcome

Title	Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (24 Hours)
Description	Pain scores (using NRS-11 scale) with active range of motion of the hip. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).
Time Frame	24 hours

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [score on a scale]	5.0	4.0

22. Secondary Outcome

Title	Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (36 Hours)
Description	Pain scores (using NRS-11 scale) with active range of motion of the hip. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).
Time Frame	36 hours

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [score on a scale]	5.0	4.5

23. Secondary Outcome

Title	Subject Satisfaction at 48 Hours
Description	Overall subject satisfaction with hospital experience at the 48 hour time point using a simple 11-point Likert scale to quantify global satisfaction. 0=completely unsatisfied, 10=completely satisfied.
Time Frame	48 hours

Outcome Measure Data

Analysis Population Description

Only completed participants are included.

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [score on a scale]	9	9

24. Secondary Outcome

Title	Pain Score, as Measured by the 11-point Numeric Rating Scale (NRS-11) (48 Hours)
Description	Pain scores (using NRS-11 scale) with active range of motion of the hip. Participants rate their pain on an 11-point scale (0=no pain at all, 10=worst imaginable pain).
Time Frame	48 hours

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [score on a scale]	5.0	5.0

25. Other Pre-specified Outcome

Title	Hospital Length of Stay
Description	Time to both discharge readiness and to actual discharge
Time Frame	0-72 hours

Outcome Measure Data

Analysis Population Description

Only completed participants are included.

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [days]	1	1

26. Other Pre-specified Outcome

Title	Overall Hospital Admission Costs
Description	difference in total hospital admission cost between groups
Time Frame	0-72 hours

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [US dollars]	14682	14782

27. Other Pre-specified Outcome

Title	Pharmacy-related Costs
Description	difference in pharmacy-related cost between groups
Time Frame	0-72 hours

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Median (Inter-Quartile Range) [US dollars]	498	510

28. Other Pre-specified Outcome

Title	Costs Related to Opioid-related Adverse Events
Description	difference in cost related to treatment of opioid-related adverse events (nausea, vomiting, pruritis, constipation, respiratory depression, dizziness) between groups
Time Frame	0-72 hours

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Mean (Standard Deviation) [US dollars]	0.80 (1.18)	0.85 (1.73)

29. Other Pre-specified Outcome

Title	Cost Associated With Nursing Interventions and Drugs to Treat Opioid-related Adverse Events
Description	mean cost (per patient) related to nursing care of opioid-related adverse events (nausea, vomiting, pruritis, constipation, respiratory depression, dizziness) in $USD
Time Frame	0-72 hours

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Intravenous Acetaminophen	Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.	Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
Measure Participants	31	29
Mean (Standard Deviation) [US dollars]	1.86 (2.68)	1.82 (3.50)

Adverse Events

Time Frame	30 days
Arm/Group Title	Intravenous Acetaminophen		Oral Acetaminophen
Arm/Group Description	Subjects receive 1000 mg acetaminophen IV immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an oral placebo. Intravenous acetaminophen: Subject receives 1 g acetaminophen by the intravenous route every 6 hours for 4 doses beginning in the preoperative holding area.		Subjects receive 1000 mg acetaminophen PO immediately preoperatively, as well as at 6, 12, and 18 hours postoperatively. At the same time points, subjects will receive an intravenous placebo. Oral acetaminophen: Subject receives 1 g acetaminophen by the oral route every 6 hours for 4 doses beginning in the preoperative holding area.
All Cause Mortality
	Intravenous Acetaminophen		Oral Acetaminophen
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/31 (0%)		0/29 (0%)
Serious Adverse Events
	Intravenous Acetaminophen		Oral Acetaminophen
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/31 (0%)		1/29 (3.4%)
Surgical and medical procedures
Postoperative hematoma	0/31 (0%)	0	1/29 (3.4%)	1
Other (Not Including Serious) Adverse Events
	Intravenous Acetaminophen		Oral Acetaminophen
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	13/31 (41.9%)		13/29 (44.8%)
Cardiac disorders
Dizziness/orthostasis	7/31 (22.6%)	7	1/29 (3.4%)	1
Gastrointestinal disorders
Nausea	9/31 (29%)	10	3/29 (10.3%)	3
constipation	3/31 (9.7%)	3	4/29 (13.8%)	4
Infections and infestations
wound erythema/drainage	1/31 (3.2%)	1	3/29 (10.3%)	3
Fever	1/31 (3.2%)	1	0/29 (0%)	0
Investigations
Abnormal lab values (INR)	1/31 (3.2%)	1	0/29 (0%)	0
Musculoskeletal and connective tissue disorders
Hip dislocation	0/31 (0%)	0	1/29 (3.4%)	1
Nervous system disorders
Polyneuropathy, peripheral	0/31 (0%)	0	1/29 (3.4%)	1
Skin and subcutaneous tissue disorders
Pruritis	2/31 (6.5%)	2	0/29 (0%)	0

Limitations/Caveats

[Not Specified]

More Information

Certain Agreements

Principal Investigators are NOT employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.