Ultrasound-guided Blocks for Ambulatory Knee Arthroscopy

Ultrasound-guided Block of the Saphenous Nerve and Obturator Nerve, Posterior Branch, for Postoperative Pain Management After Ambulatory Knee Arthroscopy

In this study, we wish to investigate the effect of ultrasound (US) -guided block of the saphenous nerve (SN) and the posterior branch of the obturator nerve (ONP) on postoperative pain and the use of opioids (morphine-like pain medicine) in the first 24 hours following ambulatory knee arthroscopy.

We wish to investigate the analgesic effect of these two blocks compared to placebo (injection of local anesthetic with known pain blocking properties compared with injection of a saline solution), when used as a supplement to conventional oral analgesics.

We hypothesize that patients receiving the active treatment may experience less pain during the first 24 hours after their operation than patients receiving the placebo treatment, and possibly require less opioid analgesics, experience less opioid related side effects and have a higher function level in this period than patients receiving the placebo treatment.

Study Overview

• Status: Completed
• Conditions: Postoperative Pain; Postoperative Nausea and Vomiting; Postoperative Function Level
• Intervention / Treatment: Drug: Paracetamol; Procedure: Block of the SN and ONP; Drug: Morphine; Drug: Ondansetron; Drug: Metoclopramide; Procedure: Placebo block

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Phase 4

Contacts and Locations

Study Locations

• Denmark
  • Copenhagen, Denmark, 2400
    • Department of Anesthesiology, Bispebjerg Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Planned ambulatory knee arthroscopy, except cruciate ligament surgery
• American Society of Anesthesiologists (ASA) class 1-3

Exclusion Criteria:

• Cannot cooperate
• Do not speak or understand Danish
• Daily use of opioid analgesics
• Allergy towards any of the drugs used in the investigation
• Medicine abuse (at the investigators discretion)
• Alcohol abuse, as defined by the National Board of Health
• General anesthesia contraindicated, or the patient wants spinal anesthesia
• Visualization of necessary structures by ultrasound not possible, or block not possible for other technical reasons

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Block arm; Ultrasound guided block of the SN and ONP with 7.5 ml of Ropivacaine 7.5 mg/ml injected at each site, respectively, immediately prior to induction of general anesthesia. Standard postoperative analgesia with paracetamol 1 g every 6 hours and Morphine 5 mg as needed. Ondansetron or Metoclopramide as needed for nausea.	Drug: Paracetamol; Other Names: Acetaminophen; Procedure: Block of the SN and ONP; 7.5 ml of Ropivacaine 7.5 mg/ml injected at each site; Other Names: Naropin; Drug: Morphine; 5 mg as needed; Drug: Ondansetron; 4 mg i.v. as needed in the PACU; Other Names: Zofran; Drug: Metoclopramide; 10 mg tablet as needed in the postoperative period after discharge from the PACU; Other Names: Primperan; Emperal
Placebo Comparator: Placebo arm; Ultrasound guided placebo block of the SN and ONP with 7.5 ml of isotonic saline solution injected at each site, respectively, immediately prior to induction of general anesthesia. Standard postoperative analgesia with paracetamol 1 g every 6 hours and Morphine 5 mg as needed. Ondansetron or Metoclopramide as needed for nausea.	Drug: Paracetamol; Other Names: Acetaminophen; Drug: Morphine; 5 mg as needed; Drug: Ondansetron; 4 mg i.v. as needed in the PACU; Other Names: Zofran; Drug: Metoclopramide; 10 mg tablet as needed in the postoperative period after discharge from the PACU; Other Names: Primperan; Emperal; Procedure: Placebo block; 7.5 ml of isotonic saline solution 154 mmol/l injected at each site; Other Names: NaCl

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain on knee flexion	VRS (Verbal Rating Scale) score 0-10 on active flexion of the knee to 45 degrees, measured at 0, ½, 1, 2, 3, 4, 6, 8, 12 and 24 hours postoperatively and analyzed by area under curve (AUC) analysis.	24 hours postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain at rest	VRS (verbal rating score) 0-10 at rest, measured at 0, ½, 1, 2, 3, 4, 6, 8, 12 and 24 hours postoperatively and analyzed by area under curve (AUC) analysis.	24 hours postoperatively
Time to opioid intake	First time the patient needs to take supplementary opioids in the postoperative period	24 hours postoperatively
Total opioid intake	Total dose of opioids taken in the first 24 hours postoperatively	24 hours
Nausea	VRS score 0-10, measured at 0, ½, 1, 2, 3, 4, 6, 8, 12 and 24 hours postoperatively and analyzed by area under curve (AUC) analysis.	24 hours postoperatively
Vomiting	Number of times the patient has vomited in the first 24 hours postoperatively.	24 hours
Use of antiemetics	Total dose of antiemetics taken during the first 24 hours postoperatively	24 hours
PACU length of stay	Total length of stay in the post anesthetic care unit (PACU) after the operation.	24 hours
Function level: Barthel Index/100	Modified Barthel Index/100 score 24 hours after the operation.	24 hours
Function level: Short form (SF) -8	Short form (SF) -8 questionnaire 24 hours postoperatively	24 hours

Collaborators and Investigators

• Sponsor: Jens Borglum Neimann
• Investigators: Principal Investigator: Bo Westergaard, MD, Department of Anesthesiology, Bispebjerg Hospital

Study record dates

Study Major Dates

• Study Start: August 1, 2012
• Primary Completion (Actual): June 1, 2013
• Study Completion (Actual): September 1, 2013

Study Registration Dates

• First Submitted: April 15, 2013
• First Submitted That Met QC Criteria: April 18, 2013
• First Posted (Estimate): April 23, 2013

Study Record Updates

• Last Update Posted (Estimate): November 6, 2013
• Last Update Submitted That Met QC Criteria: November 5, 2013
• Last Verified: November 1, 2013

More Information

Terms related to this study

• Keywords: Ultrasound; postoperative pain; Saphenous nerve; Nerve block; Obturator nerve
• Additional Relevant MeSH Terms: Pathologic Processes; Postoperative Complications; Pain; Neurologic Manifestations; Signs and Symptoms, Digestive; Nausea; Pain, Postoperative; Vomiting; Postoperative Nausea and Vomiting; Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Central Nervous System Depressants; Autonomic Agents; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Analgesics, Non-Narcotic; Antipyretics; Antiemetics; Gastrointestinal Agents; Dermatologic Agents; Analgesics, Opioid; Narcotics; Antipsychotic Agents; Tranquilizing Agents; Psychotropic Drugs; Serotonin Agents; Dopamine Agents; Serotonin Antagonists; Dopamine D2 Receptor Antagonists; Dopamine Antagonists; Anti-Anxiety Agents; Antipruritics; Acetaminophen; Morphine; Ondansetron; Metoclopramide
• Other Study ID Numbers: H-2-2011-029