A Comparison of Postoperative Analgesic Nerve Block Ropivacaine Concentrations

• Sponsor: Sylvia Wilson (Other)
• Overall Status: Completed
• CT.gov ID: NCT01556724
• Collaborator: (none)
• Enrollment: 41
• Location: 1
• Arms: 2
• Duration (Months): 59
• Patients Per Site Per Month: 0.7

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Total Hip Arthroplasty; Postoperative Pain	Drug: 0.1% or 0.2% ropivacaine nerve blocks	N/A

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.

Study Design

• Study Type: Interventional
• Actual Enrollment: 41 participants
• Allocation: Randomized
• Intervention Model: Parallel Assignment
• Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
• Primary Purpose: Treatment
• Official Title: A Comparison of 0.1 and 0.2% Ropivacaine in Lumbar Plexus Catheters After Primary Total Hip Arthroplasty: a Comparison of Postoperative Analgesia and Motor Function.
• Study Start Date: Jan 1, 2010
• Actual Primary Completion Date: May 1, 2011
• Actual Study Completion Date: Dec 1, 2014

Arms and Interventions

Arm	Intervention/Treatment
Active Comparator: 0.2% ropivacaine nerve block (standard of care) 0.2% ropivacaine in lumbar plexus nerve catheter infusions for postoperative analgesia	Drug: 0.1% 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.; Other Names: Naropin (ropivacaine hcl)
Experimental: 0.1% ropivacaine infusion in nerve block catheter 0.1% ropivacaine in lumbar plexus nerve catheter infusions	Drug: 0.1% 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.; Other Names: Naropin (ropivacaine hcl)

Outcome Measures

Primary Outcome Measures

1. Opiate Consumption Postoperatively [24 hours postoperatively]

   Postoperative opiate consumption at 24 hours

Secondary Outcome Measures

1. 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.

2. 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.

3. 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.

4. 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.

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years to 75 Years
• Sexes Eligible for Study: All
• Accepts 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.

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	UPMC Presbyterian Shadyside	Pittsburgh	Pennsylvania	United States	15232

Sponsors and Collaborators

• Sylvia Wilson

Investigators

• Principal Investigator: Sylvia Wilson, MD, University of Pittsburgh Medical Center
• Study Chair: Jacques E Chelly, MD, PhD, MBA, University of Pittsburgh Medical Center

Study Documents (Full-Text)

None provided.

More Information

Publications

• de Leeuw MA, Dertinger JA, Hulshoff L, Hoeksema M, Perez RS, Zuurmond WW, de Lange JJ. The efficacy of levobupivacaine, ropivacaine, and bupivacaine for combined psoas compartment-sciatic nerve block in patients undergoing total hip arthroplasty. Pain Pract. 2008 Jul-Aug;8(4):241-7. doi: 10.1111/j.1533-2500.2008.00209.x. Epub 2008 May 23.
• Leone S, Di Cianni S, Casati A, Fanelli G. Pharmacology, toxicology, and clinical use of new long acting local anesthetics, ropivacaine and levobupivacaine. Acta Biomed. 2008 Aug;79(2):92-105. Review.
• Marino J, Russo J, Kenny M, Herenstein R, Livote E, Chelly JE. Continuous lumbar plexus block for postoperative pain control after total hip arthroplasty. A randomized controlled trial. J Bone Joint Surg Am. 2009 Jan;91(1):29-37. doi: 10.2106/JBJS.H.00079.
• Paauwe JJ, Thomassen BJ, Weterings J, van Rossum E, Ausems ME. Femoral nerve block using ropivacaine 0.025%, 0.05% and 0.1%: effects on the rehabilitation programme following total knee arthroplasty: a pilot study. Anaesthesia. 2008 Sep;63(9):948-53. doi: 10.1111/j.1365-2044.2008.05538.x. Epub 2008 Jun 6.
• Siddiqui ZI, Cepeda MS, Denman W, Schumann R, Carr DB. Continuous lumbar plexus block provides improved analgesia with fewer side effects compared with systemic opioids after hip arthroplasty: a randomized controlled trial. Reg Anesth Pain Med. 2007 Sep-Oct;32(5):393-8.
• Zink W, Graf BM. Local anesthetic myotoxicity. Reg Anesth Pain Med. 2004 Jul-Aug;29(4):333-40. Review.

• Responsible Party: Sylvia Wilson, Regional Anesthesia Fellow, University of Pittsburgh
• ClinicalTrials.gov Identifier: NCT01556724
• Other Study ID Numbers: PRO09090339
• First Posted: Mar 16, 2012
• Last Update Posted: Jan 17, 2018
• Last Verified: Dec 1, 2017

• Keywords provided by Sylvia Wilson, Regional Anesthesia Fellow, University of Pittsburgh: Peripheral nerve blocks; Ropivacaine concentrations in lumbar plexus catheters; Postoperative pain; Total hip replacement
• Additional relevant MeSH terms: Pain, Postoperative; Ropivacaine

Study Results

Participant Flow

Pre-assignment Detail	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%.

Arm/Group Title	0.2% Ropivacaine	0.1% Ropivacaine
Arm/Group Description	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.	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.
Period Title: Overall Study
STARTED	16	14
COMPLETED	16	14
NOT COMPLETED	0	0

Baseline Characteristics

Arm/Group Title	0.2% Ropivacaine	0.1% Ropivacaine	Total
Arm/Group Description	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.	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.	Total of all reporting groups
Overall Participants	16	14	30
Age (Count of Participants)
<=18 years	0 0%	0 0%	0 0%
Between 18 and 65 years	11 68.8%	12 85.7%	23 76.7%
>=65 years	5 31.3%	2 14.3%	7 23.3%
Age (years) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [years]	59.0 (8.8)	56.1 (10.8)	57.5 (9.8)
Sex: Female, Male (Count of Participants)
Female	7 43.8%	8 57.1%	15 50%
Male	9 56.3%	6 42.9%	15 50%
Region of Enrollment (participants) [Number]
United States	16 100%	14 100%	30 100%

Outcome Measures

1. Primary Outcome

Title	Opiate Consumption Postoperatively
Description	Postoperative opiate consumption at 24 hours
Time Frame	24 hours postoperatively

Outcome Measure Data

Analysis Population Description

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/Group Title	0.2% Ropivacaine	0.1% Ropivacaine
Arm/Group Description	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.	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.
Measure Participants	16	14
Mean (95% Confidence Interval) [mg]	8.21	8.02

2. Secondary Outcome

Title	Patient Satisfaction With Pain Control
Description	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

Outcome Measure Data

Analysis Population Description

Patient satisfaction with pain control at 24 hours.

Arm/Group Title	0.2% Ropivacaine	0.1% Ropivacaine Infusion in Nerve Block Catheter
Arm/Group Description	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.	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.
Measure Participants	16	14
Median (95% Confidence Interval) [units on a scale]	8	9

3. Secondary Outcome

Title	Numeric Rating Scale Pain Score With Movement at 24 Hours
Description	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

Outcome Measure Data

Analysis Population Description

NRS pain scores at 24 hours postoperatively at rest and in movement.

Arm/Group Title	0.2% Ropivacaine Nerve Block (Standard of Care)	0.1% Ropivacaine Infusion in Nerve Block Catheter
Arm/Group Description	0.1% 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 continuo	0.1% 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 w
Measure Participants	16	14
Median (95% Confidence Interval) [units on a scale]	7	7

4. Secondary Outcome

Title	Number of Participants With Increased Infusion Rates
Description	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)

Outcome Measure Data

Analysis Population Description

The number of participants with requiring increased infusion rates.

Arm/Group Title	0.2% Ropivacaine Nerve Block (Standard of Care)	0.1% Ropivacaine Infusion in Nerve Block Catheter
Arm/Group Description	0.1% 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 continuo	0.1% 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 w
Measure Participants	16	14
Count of Participants [Participants]	4 25%	3 21.4%

5. Secondary Outcome

Title	Number of Participants With Decreased Infusion Rates
Description	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)

Outcome Measure Data

Analysis Population Description

Number of patient requiring decreased infusion rates.

Arm/Group Title	0.2% Ropivacaine Nerve Block (Standard of Care)	0.1% Ropivacaine Infusion in Nerve Block Catheter
Arm/Group Description	0.1% 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 continuo	0.1% 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 w
Measure Participants	16	14
Count of Participants [Participants]	1 6.3%	1 7.1%

Adverse Events

Time Frame	Adverse event were analyzed after lumbar plexus perineural catheter removal on POD2 as this was the end of the data collection period.
Arm/Group Title	0.2% Ropivacaine		0.1% Ropivacaine Infusion in Nerve Block Catheter
Arm/Group Description	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.		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.
All Cause Mortality
	0.2% Ropivacaine		0.1% Ropivacaine Infusion in Nerve Block Catheter
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/16 (0%)		0/14 (0%)
Serious Adverse Events
	0.2% Ropivacaine		0.1% Ropivacaine Infusion in Nerve Block Catheter
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/16 (0%)		0/14 (0%)
Other (Not Including Serious) Adverse Events
	0.2% Ropivacaine		0.1% Ropivacaine Infusion in Nerve Block Catheter
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/16 (0%)		0/14 (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.