IV Acetaminophen as an Adjunct Analgesic in Cardiac Surgery (CarDolMev)

Efficacy of Perioperative Intravenous Acetaminophen as an Adjunct Analgesic in Cardiac Surgery Patients

Patients undergoing cardiac surgery experience significant postoperative pain, which may impact postoperative outcomes. The aim of this single center, double-blind, randomized, placebo controlled trial is to determine if intravenous (IV) acetaminophen will significantly decrease 24 hour postoperative opioid consumption.

Study Overview

• Status: Completed
• Conditions: Acute Pain; Hyperalgesia
• Intervention / Treatment: Drug: IV acetaminophen; Drug: Placebo

Detailed Description

Subjects will be randomized to a placebo or treatment group in a 1:1 ratio in blocks of 10 using an online randomization tool. The randomization table numbers for the subjects who are randomized, but subsequently withdrew consent after enrollment or had their case cancelled will be also included. Only the research pharmacists will have access to the securely-stored randomized group allocation list, which will remain blinded until statistical analysis is completed. A research pharmacist will prepare 100 mL normal saline infusion bags, which contain either 1,000 mg IV acetaminophen or placebo. Identical in appearance, the bags will be then delivered to either the operating room satellite pharmacy or ICU.

The subjects will receive a total of 6 doses of 1,000 mg IV acetaminophen or placebo at the following time points: (1) immediately after anesthesia induction, but prior to the incision, (2) at the end of surgery with (3) four additional doses administered postoperatively in the ICU every 6 hours for the first 24 hours. The first ICU dose will be administered 6 hours after the arrival in the ICU. The intraoperative study drug doses will be administered by one of the investigators (SJ or PR) and postoperative ICU study drug doses will be administered by nursing staff.

Anesthesia and Pain Management All of the study subjects will undergo cardiac surgery under general anesthesia. The cardiac surgery procedures will include standard midline sternotomy and in cases involving coronary artery bypass grafting, harvesting of saphenous vein and internal mammary artery grafts. Cardiopulmonary bypass will be conducted using membrane oxygenation. All subjects will undergo standardized induction per current practice at our institution with lidocaine (1-1.5 mg/kg), fentanyl (5-10 μg/kg), etomidate (0.2 mg/kg) and either rocuronium (1 mg/kg) or vecuronium (0.1 mg/kg). Succinylcholine (1-1.5 mg/kg) will be used when rapid sequence induction is appropriate. The anesthesia will be maintained with isoflurane. The intraoperative analgesia will consist of fentanyl or hydromorphone boluses, which will be administered at the discretion of the anesthesia provider. Postoperative pain management will consist of nursing fentanyl boluses while patients were sedated and mechanically ventilated. Following extubation, patients will receive oral oxycodone (5 to 10 mg orally every 3 hours as needed) with intravenous hydromorphone or morphine boluses for breakthrough pain.

Opioid Consumption At the end of the surgery, subjects will be transferred to the ICU while intubated and sedated on a propofol infusion. The time of arrival to the ICU will be considered time 0 for the purpose of postoperative study drug dosing and further evaluations. The 24 hour opioid consumption will be obtained from the electronic medication administration record and will be expressed in morphine equivalents per standard opioid conversions.

Secondary Outcomes The secondary outcomes will include 48 hour postoperative opioid consumption. The ICU nursing staff will be trained to use pain diaries containing an eleven point (0 to 10) Numeric Rating Scale (NRS). Pain assessments at rest and with movement will be recorded by the nursing staff at 6, 12, 18 and 24 hours postoperatively while one of the investigators will record pain assessments at 48 hours postoperatively. At the same times postoperatively, patients will be also assessed for opioid related adverse effects including nausea and vomiting, pruritus, respiratory depression, dizziness and sedation using a numeric scale (0 = no adverse effects, 1 = mild adverse effects not requiring treatment, 2 = moderate adverse effects requiring treatment and 3 = severe adverse effects refractory to treatment).

In addition, the ICU nursing staff will be instructed to complete the "Extubation Criteria" checklist for each 2-hour time period until extubation and the "ICU Discharge Criteria" checklist for each 4-hour time period until discharge from the ICU. A short "Patient Satisfaction Survey" will be also completed during the 24 and 48 hour follow up visits. The extent to which subjects overall pain experience met their expectations will be converted to the Likert scale with the following values: not at all (1), a little (2), a fair amount (3), very much (4) and extremely well (5).

Wound hyperalgesia at 24 and 48 hours postoperatively will be measured using a method previously described by Stubhaug et al. In brief, the lateral right chest area will be first stimulated where no pain sensation is experienced using a 180 gram von Frey filament (# 6.45). The filament will be then moved toward the incision in 1 cm steps until a distinct change in perception (painful, sore, or sharp feeling) is reported and the remaining distance to the incision will be noted. If no change in sensation appears, stimulation will be stopped at 4 cm from the incision. Wound hyperalgesia will be determined by testing the right side of the chest along five horizontal lines vertically separated by 2 cm at right angles to the incision. Only the right side of the chest will be chosen to avoid confounding skin sensation changes from the left internal mammary artery harvesting. The distance (in cm) from the incision to the point where sensations changed will be measured 5 times and the average distance will be used as wound hyperalgesia.

Data and Statistical Analysis A power analysis determined that 35 patients in each group will be needed to have an 80% chance to detect a 30% difference in mean 24 hour cumulative opioid consumption for the first 24 hour period after surgery using 2-sided t-tests with a set α level of 0.05, and an anticipated dropout rate of less than 15%.

Fisher's exact or Chi-squared and t-tests will be used to compare patient characteristics and intraoperative variables between the placebo and treatment group. Outcome variables will be compared between groups using t-tests and analysis of covariance controlling for age, sex, body mass index (BMI) and intraoperative hydromorphone. Scatter plots will be used to display the data to look for interactions, outliers and skewed distributions. The best fit line will be assessed by the F-test on the interaction between age and treatment group in an analysis of covariance. The analyses will be performed using SPSS software, version 15 (SPSS Inc., Chicago, IL). All reported P values will be 2-sided, and a significance level of P < 0.05 will be used.

• Study Type: Interventional
• Enrollment (Actual): 68
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • Washington
    • Seattle, Washington, United States, 98195
      • University of Washington Medical Center, Department of ANesthesiology and Pain Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• (1) subjects who clinically consented to elective sternotomy for coronary artery bypass grafting (CABG), heart valve repair or replacement under general anesthesia, and (2) ages between 18 and 75 years

Exclusion Criteria:

• (1) subject refusal, (2) non-English speaking, (3) previous chronic or neuropathic pain, (4) previous chronic use of opioids, (5) history of psychiatric disorder, (6) allergy to acetaminophen, (7) severely impaired liver and kidney function and (8) previous sternotomy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: QUADRUPLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: IV acetaminophen; Study subjects receiving IV acetaminophen	Drug: IV acetaminophen; Total of 6 doses of 1,000 mg IV acetaminophen at the following time points: (1) immediately after anesthesia induction, but prior to the incision, (2) at the end of surgery with (3) four additional doses administered postoperatively in the ICU every 6 hours for the first 24 hours.; Other Names: Ofirmev
PLACEBO_COMPARATOR: Normal saline; Study subjects receiving placebo	Drug: Placebo; Total of 6 doses of 100 mL of normal saline at the following time points: (1) immediately after anesthesia induction, but prior to the incision, (2) at the end of surgery with (3) four additional doses administered postoperatively in the ICU every 6 hours for the first 24 hours.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
24 Hour Postoperative Opioid Consumption	The 24 hour postoperative opioid consumption will be obtained from the electronic medication administration record and expressed in morphine equivalents.	24 hours after arriving in ICU

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
48 Hour Postoperative Opioid Consumption	48 hour postoperative opioid consumption will be obtained from the electronic medication administration record and expressed in morphine equivalents.	48 hours after arriving in ICU
24 Hour Postoperative Pain Scores at Rest	Pain scores at rest will be recorded on Numeric Rating Scale by nursing staff. The Numeric Rating Scale ranges from 0 to 10 (0 - no pain, 1-2-3 - mild pain, 4-5-6 - moderate pain, 7-8-9 - severe pain, 10 - worst pain imaginable).	24 hours after arriving in ICU
48 Hour Postoperative Pain Scores at Rest	Pain scores at rest will be recorded on Numeric Rating Scale by nursing staff. The Numeric Rating Scale ranges from 0 to 10 (0 - no pain, 1-2-3 - mild pain, 4-5-6 - moderate pain, 7-8-9 - severe pain, 10 - worst pain imaginable).	48 hours after arriving in ICU
24 Hour Postoperative Pain Scores With Movement	Pain scores at rest will be recorded on Numeric Rating Scale by nursing staff. The Numeric Rating Scale ranges from 0 to 10 (0 - no pain, 1-2-3 - mild pain, 4-5-6 - moderate pain, 7-8-9 - severe pain, 10 - worst pain imaginable).	24 hours after arriving in ICU
48 Hour Postoperative Pain Scores With Movement	Pain scores at rest will be recorded on Numeric Rating Scale by nursing staff. The Numeric Rating Scale ranges from 0 to 10 (0 - no pain, 1-2-3 - mild pain, 4-5-6 - moderate pain, 7-8-9 - severe pain, 10 - worst pain imaginable).	48 hours after arriving in ICU
24 Hour Wound Hyperalgesia	Wound hyperalgesia will be determined by testing the right side of the chest along five horizontal lines vertically separated by 2 cm at right angles to the incision using 180 gram von Frey filament (# 6.45).	24 hours after arriving in ICU
48 Hour Wound Hyperalgesia	Wound hyperalgesia will be determined by testing the right side of the chest along five horizontal lines vertically separated by 2 cm at right angles to the incision using 180 gram von Frey filament (# 6.45).	48 hours after arriving in ICU
Length of Mechanical Ventilation	The length of mechanical ventilation will be determined based on the "Extubation Criteria" checklist that will be completed by nursing staff every 2 hours until extubation.	From the time of arrival in ICU until extubation
Length of ICU Stay	The length of ICU stay will be determined based on the "ICU Discharge Criteria" checklist that will be completed by nursing staff every 4 hours until ICU discharge.	From the time of arrival in ICU until ICU discharge
48 Hour Patient Satisfaction	"The extent to which subjects overall pain experience met their expectations" question responses were converted to the Likert scale with the following values: not at all (1), a little (2), a fair amount (3), very much (4) and extremely well (5).	48 hours after arriving in ICU
24 Hour Nausea	Opioid related adverse effects were recorded using a numeric scale (0 = no adverse effects, 1 = mild adverse effects not requiring treatment, 2 = moderate adverse effects requiring treatment and 3 = severe adverse effects refractory to treatment). Presence of nausea was defined as numeric scale response 2 (moderate adverse effects requiring treatment) or 3 (severe adverse effects refractory to treatment).	24 hours after arriving in ICU
48 Hour Nausea	Opioid related adverse effects were recorded using a numeric scale (0 = no adverse effects, 1 = mild adverse effects not requiring treatment, 2 = moderate adverse effects requiring treatment and 3 = severe adverse effects refractory to treatment). Presence of nausea was defined as numeric scale response 2 (moderate adverse effects requiring treatment) or 3 (severe adverse effects refractory to treatment).	48 hours after arriving in ICU
24 Hour Pruritus	Opioid related adverse effects were recorded using a numeric scale (0 = no adverse effects, 1 = mild adverse effects not requiring treatment, 2 = moderate adverse effects requiring treatment and 3 = severe adverse effects refractory to treatment). Presence of pruritus was defined as numeric scale response 1 (mild adverse effects not requiring treatment), 2 (moderate adverse effects requiring treatment) or 3 (severe adverse effects refractory to treatment).	24 hours after arriving in ICU
48 Hour Pruritus	Opioid related adverse effects were recorded using a numeric scale (0 = no adverse effects, 1 = mild adverse effects not requiring treatment, 2 = moderate adverse effects requiring treatment and 3 = severe adverse effects refractory to treatment). Presence of pruritus was defined as numeric scale response 1 (mild adverse effects not requiring treatment), 2 (moderate adverse effects requiring treatment) or 3 (severe adverse effects refractory to treatment).	48 hours after arriving in ICU
24 Hour Sedation	Opioid related adverse effects were recorded using a numeric scale (0 = no adverse effects, 1 = mild adverse effects not requiring treatment, 2 = moderate adverse effects requiring treatment and 3 = severe adverse effects refractory to treatment). Presence of sedation was defined as numeric scale response 1 (mild adverse effects not requiring treatment), 2 (moderate adverse effects requiring treatment) or 3 (severe adverse effects refractory to treatment).	24 hours after arriving in ICU
48 Hour Sedation	Opioid related adverse effects were recorded using a numeric scale (0 = no adverse effects, 1 = mild adverse effects not requiring treatment, 2 = moderate adverse effects requiring treatment and 3 = severe adverse effects refractory to treatment). Presence of sedation was defined as numeric scale response 1 (mild adverse effects not requiring treatment), 2 (moderate adverse effects requiring treatment) or 3 (severe adverse effects refractory to treatment).	48 hours after arriving in ICU
24 Hour Respiratory Depression	Opioid related adverse effects were recorded using a numeric scale (0 = no adverse effects, 1 = mild adverse effects not requiring treatment, 2 = moderate adverse effects requiring treatment and 3 = severe adverse effects refractory to treatment). Presence of respiratory depression was defined as numeric scale response 1 (mild adverse effects not requiring treatment), 2 (moderate adverse effects requiring treatment) or 3 (severe adverse effects refractory to treatment).	24 hours after arriving in ICU
48 Hour Respiratory Depression	Opioid related adverse effects were recorded using a numeric scale (0 = no adverse effects, 1 = mild adverse effects not requiring treatment, 2 = moderate adverse effects requiring treatment and 3 = severe adverse effects refractory to treatment). Presence of respiratory depression was defined as numeric scale response 1 (mild adverse effects not requiring treatment), 2 (moderate adverse effects requiring treatment) or 3 (severe adverse effects refractory to treatment).	48 hours after arriving in ICU
24 Hour Dizziness	Opioid related adverse effects were recorded using a numeric scale (0 = no adverse effects, 1 = mild adverse effects not requiring treatment, 2 = moderate adverse effects requiring treatment and 3 = severe adverse effects refractory to treatment). Presence of dizziness was defined as numeric scale response 1 (mild adverse effects not requiring treatment), 2 (moderate adverse effects requiring treatment) or 3 (severe adverse effects refractory to treatment).	24 hours after arriving in ICU
48 Hour Dizziness	Opioid related adverse effects were recorded using a numeric scale (0 = no adverse effects, 1 = mild adverse effects not requiring treatment, 2 = moderate adverse effects requiring treatment and 3 = severe adverse effects refractory to treatment). Presence of dizziness was defined as numeric scale response 1 (mild adverse effects not requiring treatment), 2 (moderate adverse effects requiring treatment) or 3 (severe adverse effects refractory to treatment).	48 hours after arriving in ICU

Collaborators and Investigators

• Sponsor: University of Washington
• Collaborators: Mallinckrodt
• Investigators: Study Director: Lisa Flint, BS, University of Washington

Study record dates

Study Major Dates

• Study Start: July 1, 2012
• Primary Completion (ACTUAL): December 1, 2013
• Study Completion (ACTUAL): August 1, 2014

Study Registration Dates

• First Submitted: February 28, 2012
• First Submitted That Met QC Criteria: March 2, 2012
• First Posted (ESTIMATE): March 5, 2012

Study Record Updates

• Last Update Posted (ESTIMATE): June 21, 2016
• Last Update Submitted That Met QC Criteria: May 12, 2016
• Last Verified: May 1, 2016

More Information

Terms related to this study

• Keywords: Cardiac surgery; Patient Satisfaction; Acute Pain; Intravenous Acetaminophen; Wound Hyperalgesia
• Additional Relevant MeSH Terms: Nervous System Diseases; Pain; Neurologic Manifestations; Sensation Disorders; Somatosensory Disorders; Acute Pain; Hyperalgesia; Physiological Effects of Drugs; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Analgesics, Non-Narcotic; Antipyretics; Acetaminophen
• Other Study ID Numbers: 42204-D

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO