Postoperative Pain
Conditions
Keywords
Peripheral regional anesthesia
Brief summary
BACKGROUND Orthopedic surgery can be severely painful, and peripheral regional anesthesia is highly recommended as part of the perioperative pain treatment. Whether catheter-based techniques are better than single injection techniques are debatable. Furthermore, in catheter-based techniques, whether a low-dose automated, periodic infusion can produce similar analgesic effectiveness compared to a conventional, high dose, continuous infusion has never been explored. AIM Comparison of the analgesic effectiveness of a low-dose automated, periodic infusion, a conventional continuous infusion and patient-controlled boluses only in catheter-based nerve blocks for patients undergoing orthopedic surgery to the foot or ankle.
Detailed description
BACKGROUND Orthopedic surgery has been reported to be moderate to severely painful in approximately 50 % of patients. Peripheral regional anesthesia (PRA) using single injection nerve blocks is highly recommended as part of a multimodal, perioperative, analgesic treatment. Patients who are expected to have postoperative, severe pain exceeding the duration of a single injection nerve block may benefit from a catheter-based nerve block (CBNB) using either a continuous infusion (CI) or intermittent infusions of local anesthetics (LA). Intermittent boluses can be either patient-controlled or prescribed in combination with a continuous infusion or as prespecified intermittent boluses. Whether a CBNB treatment is superior to a single injection nerve block after orthopedic surgery remains unanswered. There are several challenges when using a CBNB treatment: The dosing or delivery method may be either insufficient and thus not pain relieving or too powerful resulting in dense motor block and limb anesthesia which may compromise safety and rehabilitation. The peripheral nerve block catheter may also displace and therefore deposit LA too far from the targeted nerve(s) to produce an effective nerve block. Previous studies suggest that an automated periodic infusion (API) regimen is superior to CI. It seems that an API produces better pain control, a lower analgesic consumption over time and less motor inhibition. This is well-described for epidural catheters for laboring women, but evidence is also apparent in PRA. Adding a PCA bolus option to a catheter-based nerve block treatment may even out the difference in pain scores between API and CI. However, it seems that API groups require less LA via PCA function. Reducing LA consumption is of great importance for ambulatory patients whose LA reservoir is limited, but also for all other orthopedic patients whose motor block should be minimized in order to optimize rehabilitation. OBJECTIVES To investigate whether a low-dose API with patient-controlled bolus option can produce a similar analgesic effect compared to a conventional, high dose, CI with patient-controlled bolus option in catheter-based peripheral nerve blocks for patients undergoing orthopedic surgery to the foot or ankle. Analgesic effectiveness will be compared with a group only given the patient-controlled bolus option. HYPOTHESIS Low dose API with supplemental patient-controlled bolus option will provide pain-relieving therapy not inferior to a conventional CI with supplemental patient-controlled bolus option. The intervention group receiving patient-controlled boluses only will experience more pain breakthrough.
Interventions
DRUGRopivacaine 0.2%
Perineural infusion of Ropivacaine 0.2% using a peripheral nerve block catheter and a portable infusion pump.
Sponsors
Innovation Fund Denmark
Nordsjaellands Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Masking description
All patients and outcome assessors will be blinded to the delivery administrations. Investigators will not be present while programming of the infusion pump is taking place. The display of the infusion pump will be concealed at all times after initiation. Furthermore, throughout the trial, the infusion pump will be concealed from the patient through a non-transparent bag. Trial interventions will not be visible in electronic patient charts. The infusion pump is making a discrete noise when administering medications. To make sure that the PCA group and the continuous infusion group is blinded to interventions, a sham administration is activated every 8th hour. This sham administration will be 0.1 mL of ropivacaine 0.2%. Such a small dose of LA will not have any anesthetic effect nor pose a risk for the patient.
Intervention model description
3 arms (API, CI and PCA only)
Eligibility
Sex/Gender
ALL
Age
18 Years to 99 Years
Healthy volunteers
No
Inclusion criteria
1. American Society of Anesthesiologists Classification I-III 2. Normal cognitive function in order to sign written, informed consent and to understand trial protocol 3. Agreement to the trial protocol, including the randomized manner
Exclusion criteria
1. Allergy to LA 2. Infection in or near insertion site of the peripheral nerve catheter 3. Anatomical abnormalities preventing successful peripheral nerve catheter insertion 4. Habitual use of opioids 5. Pregnancy or breastfeeding (disproved by a negative pregnancy test before trial inclusion)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Postoperative pain, 1-72 hours postoperatively | 1-72 hours | Postoperative pain using the visual analogue pain scale (VAS, 0-100 milimetres). Measurements will be patient-reported. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Opioid consumption, 1-72 hours postoperatively | 1-72 hours | Tablets consumed during the period of investigation |
| Volume of patient-initiated boluses, 1-72 hours postoperatively | 1-72 hours | Volume of ropivacaine 0.2 % (mL) used for patient-initiated boluses, 1-72 hours postoperatively |
Other
| Measure | Time frame | Description |
|---|---|---|
| Opioid related side effects | 1-72 hours | Patient reported symptoms: dizziness, nausea, itching, constipation |
| Sensory nerve block | 1-72 hours | Insensitivity towards cold in the lateral aspects of the lower leg and beneath the foot. This will be recorded by the patient using a cold glass vial stored in a refrigerator until its use. |
| Pain at bolus request | 1-72 hours | Pain (VAS, 0-100 milimetres) at the time of patient-initiated bolus |
| Motor nerve block | 1-72 hours | Degree of motor nerve block, defined by paresis or paralysis in the ankle dorsi- and plantarflexion movement. |
Countries
Denmark
Outcome results
None listed