Postoperative Pain, Total Hip Arthroplasty
Conditions
Keywords
Peripheral nerve blocks, Ropivacaine concentrations in lumbar plexus catheters, Postoperative pain, Total hip replacement
Brief summary
Peripheral nerve blocks are the standard of care for pain management after hip replacement surgery at UPMC Shadyside. This prospective, randomized study is intended to assess the effect of 0.1 versus 0.2% ropivacaine in lumbar plexus nerve catheter infusions after total hip arthroplasty. Ropivacaine peripheral nerve block infusions have been utilized as the standard of care at UPMC Shadyside for many years. Ropivacaine, a less potent left-isomer of bupivacaine, is often used in place of bupivacaine due to less motor blockade and less severe cardiovascular and central nervous system potential toxicity. The primary goal of this study to examine the effect of a low concentration infusion of ropivacaine (0.1%) on postoperative analgesia (evaluated by opioid consumption after 36 hours) compared with the standard accepted concentration of 0.2% ropivacaine in lumbar plexus catheters after primary total hip arthroplasty. Secondary goals are to examine motor function, VAS scores and patient satisfaction with pain control in low concentration 0.1% ropivacaine compared with 0.2% ropivacaine lumbar plexus infusions upto 36 hours after primary total hip arthroplasty.
Detailed description
Lumbar plexus catheters are the standard of care for postoperative pain management following total hip arthroplasty (THA) at UPMC Shadyside. The safety and efficacy of this technique has been demonstrated by multiple studies. Ropivacaine 0.2% was used for many years at UPMC Shadyside and throughout the UPMC system and this concentration of ropivacaine is the standard local anesthetic utilized by multiple other studies. However, this concentration of ropivacaine was later decreased to 0.1% in our institution in order to decrease patient's motor weakness and promote postoperative physical therapy. Patients were clinically observed to continue to have adequate postoperative analgesia while demonstrating improved motor function. A randomized, double blinded clinical trial has never compared 0.1 and 0.2% ropivacaine.
Interventions
DRUG0.1% or 0.2% ropivacaine nerve blocks
Either 0.1% or 0.2% ropivacaine will be infused at 7 mL/hr through lumbar plexus nerve block catheter based upon randomization, and can then receive a 6 ml bolus of either 0.1% or 0.2% ropivacaine. Additional pain relief will be available by nurse administered boluses of additional local anesthetic (from their randomized infusion) with a maximum dose of an extra 3 ml per bolus and limited to one bolus per hour. This bolus of their randomized local anesthetic will remain available until the nerve catheters are removed. Nerve block infusion rates may be increased to 9 ml/h for patients with increased pain without increased motor blockade as determined by the acute interventional perioperative pain service (AIPPS) or decreased to 5 ml/h for patients with increased motor blockade or weakness from the peripheral nerve block as determined by the AIPPS .All continuous lumbar plexus catheters will be removed on post operative day (POD) 2.
Sponsors
Sylvia Wilson
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
* Age 18-75 years old * American Society of Anesthesiologists physical status score I-III * Scheduled for primary total hip arthroplasty at UPMC Shadyside Hospital in Pittsburgh, PA. * No contraindications to peripheral nerve catheter placement * Patients not expected to receive therapeutic anticoagulation in the postoperative period. * No known drug allergies to study medications * Patients willing to receive spinal anesthesia as operative anesthetic
Exclusion criteria
* Age under 18 years or older than 75 years. * Any contraindication to a placement of continuous lumbar plexus peripheral nerve catheter. * American Society of Anesthesiologist physical status IV or greater. * Chronic painful conditions. * Preoperative opioid tolerant use (opioid use for greater than 6 contiguous months before surgery). * Coagulation abnormalities or patients who are expected to be on therapeutic anticoagulants postoperatively. * Allergy to any of the drugs/agents used study protocol. * Pregnancy * Having an altered mental status (not oriented to place, person, or time) * Any comorbid condition that, in the judgment of the consulting orthopedic surgeon or intraoperative anesthesiologist, would proscribe the patient from any aspect of the study. * Patient refusal. * Patient requiring postoperative management in the ICU * Lumbar plexus catheter placed by loss of resistance technique.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Opiate Consumption Postoperatively | 24 hours postoperatively | Postoperative opiate consumption at 24 hours |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Patient Satisfaction With Pain Control | 24 hours postoperatively | Patient satisfaction with pain control at 24 hours (0-10 scale). Patients' satisfaction was assessed using an 11-point numeric scale (0-10, 0 = unsatisfied and 10 = very satisfied). Scores at 24 hours were not averaged with any other scores. |
| Numeric Rating Scale Pain Score With Movement at 24 Hours | 24 hours postoperatively | Numeric rating scale (NRS) pain score with movement were assessed at 24 hours. Pain scores were followed using an 11-point NRS (0 = no pain and 10 = worst imaginable pain). Scores at 24 hours were not averaged with any other scores. |
| Number of Participants With Increased Infusion Rates | Subjects will be followed postoperatively until postoperative day 2 (i.e. the discontinuation of the lumbar plexus catheters) | Number of patients requiring increased infusion rates to 9 mL/hour to better optimize pain control. |
| Number of Participants With Decreased Infusion Rates | Subjects will be followed postoperatively until postoperative day 2 (i.e. the discontinuation of the lumbar plexus catheters) | Number of patient requiring decreased infusion rates decreased to 5 mL/hour due to increased motor blockade. |
Countries
United States
Participant flow
Pre-assignment details
Forty-one patients signed an informed consent form. Eleven patients were excluded: six for inability to achieve \<0.5mA quadriceps stimulation for lumbar plexus block placement and five for general anesthesia. After pharmacy randomization, 14 received ropivacaine 0.1% and 16 received ropivacaine 0.2%.
Participants by arm
| Arm | Count |
|---|---|
| 0.2% Ropivacaine 0.2% ropivacaine
Either 0.1% or 0.2% ropivacaine will be infused at 7 mL/hr through lumbar plexus nerve block catheter based upon randomization, and can then receive a 6 ml bolus of either 0.1% or 0.2% ropivacaine. Additional pain relief will be available by nurse administered boluses of additional local anesthetic (from their randomized infusion) with a maximum dose of an extra 3 ml per bolus and limited to one bolus per hour. This bolus of their randomized local anesthetic will remain available until the nerve catheters are removed. Nerve block infusion rates may be increased to 9 ml/h for patients with increased pain without increased motor blockade as determined by the acute interventional perioperative pain service (AIPPS) or decreased to 5 ml/h for patients with increased motor blockade or weakness from the peripheral nerve block as determined by the AIPPS .All continuous lumbar plexus catheters will be removed on post operative day (POD) 2. | 16 |
| 0.1% Ropivacaine 0.1% ropivacaine
Either 0.1% or 0.2% ropivacaine will be infused at 7 mL/hr through lumbar plexus nerve block catheter based upon randomization, and can then receive a 6 ml bolus of either 0.1% or 0.2% ropivacaine. Additional pain relief will be available by nurse administered boluses of additional local anesthetic (from their randomized infusion) with a maximum dose of an extra 3 ml per bolus and limited to one bolus per hour. This bolus of their randomized local anesthetic will remain available until the nerve catheters are removed. Nerve block infusion rates may be increased to 9 ml/h for patients with increased pain without increased motor blockade as determined by the acute interventional perioperative pain service (AIPPS) or decreased to 5 ml/h for patients with increased motor blockade or weakness from the peripheral nerve block as determined by the AIPPS .All continuous lumbar plexus catheters will be removed on post operative day (POD) 2. | 14 |
| Total | 30 |
Baseline characteristics
| Characteristic | 0.1% Ropivacaine | 0.2% Ropivacaine | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 2 Participants | 5 Participants | 7 Participants |
| Age, Categorical Between 18 and 65 years | 12 Participants | 11 Participants | 23 Participants |
| Age, Continuous | 56.1 years STANDARD_DEVIATION 10.8 | 59.0 years STANDARD_DEVIATION 8.8 | 57.5 years STANDARD_DEVIATION 9.8 |
| Region of Enrollment United States | 14 participants | 16 participants | 30 participants |
| Sex: Female, Male Female | 8 Participants | 7 Participants | 15 Participants |
| Sex: Female, Male Male | 6 Participants | 9 Participants | 15 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 16 | 0 / 14 |
| other Total, other adverse events | 0 / 16 | 0 / 14 |
| serious Total, serious adverse events | 0 / 16 | 0 / 14 |
Outcome results
Primary
Opiate Consumption Postoperatively
Postoperative opiate consumption at 24 hours
Time frame: 24 hours postoperatively
Population: Forty-one patients signed informed consent and underwent primary THA. Eleven patients were excluded: six for inability to achieve \<0.5mA quadriceps stimulation for lumbar plexus block and five for general anesthesia. The study was completed after pharmacy randomization 30 patients: 16 in 0.2% and 14 in 0.1% group.
| Arm | Measure | Value (MEAN) |
|---|---|---|
| 0.2% Ropivacaine | Opiate Consumption Postoperatively | 8.21 mg |
| 0.1% Ropivacaine | Opiate Consumption Postoperatively | 8.02 mg |
Secondary
Number of Participants With Decreased Infusion Rates
Number of patient requiring decreased infusion rates decreased to 5 mL/hour due to increased motor blockade.
Time frame: Subjects will be followed postoperatively until postoperative day 2 (i.e. the discontinuation of the lumbar plexus catheters)
Population: Number of patient requiring decreased infusion rates.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| 0.2% Ropivacaine | Number of Participants With Decreased Infusion Rates | 1 Participants |
| 0.1% Ropivacaine | Number of Participants With Decreased Infusion Rates | 1 Participants |
Secondary
Number of Participants With Increased Infusion Rates
Number of patients requiring increased infusion rates to 9 mL/hour to better optimize pain control.
Time frame: Subjects will be followed postoperatively until postoperative day 2 (i.e. the discontinuation of the lumbar plexus catheters)
Population: The number of participants with requiring increased infusion rates.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| 0.2% Ropivacaine | Number of Participants With Increased Infusion Rates | 4 Participants |
| 0.1% Ropivacaine | Number of Participants With Increased Infusion Rates | 3 Participants |
Secondary
Numeric Rating Scale Pain Score With Movement at 24 Hours
Numeric rating scale (NRS) pain score with movement were assessed at 24 hours. Pain scores were followed using an 11-point NRS (0 = no pain and 10 = worst imaginable pain). Scores at 24 hours were not averaged with any other scores.
Time frame: 24 hours postoperatively
Population: NRS pain scores at 24 hours postoperatively at rest and in movement.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| 0.2% Ropivacaine | Numeric Rating Scale Pain Score With Movement at 24 Hours | 7 units on a scale |
| 0.1% Ropivacaine | Numeric Rating Scale Pain Score With Movement at 24 Hours | 7 units on a scale |
Secondary
Patient Satisfaction With Pain Control
Patient satisfaction with pain control at 24 hours (0-10 scale). Patients' satisfaction was assessed using an 11-point numeric scale (0-10, 0 = unsatisfied and 10 = very satisfied). Scores at 24 hours were not averaged with any other scores.
Time frame: 24 hours postoperatively
Population: Patient satisfaction with pain control at 24 hours.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| 0.2% Ropivacaine | Patient Satisfaction With Pain Control | 8 units on a scale |
| 0.1% Ropivacaine | Patient Satisfaction With Pain Control | 9 units on a scale |