Postoperative Pain
Conditions
Keywords
intravenous lidocaine, erector spinae plane block, quadratus lumborum block, thoracic surgery, abdominal surgery, continuous peripheral nerve block
Brief summary
A multimodal analgesic regimen including regional anesthesia is used at UPMC Shadyside for primary thoracic and major abdominal surgeries. The current standard-of-care regional anesthesia techniques include Erector Spinae Plane (ESP) block for video assisted thorascopic surgery (VATS) and Quadratus Lumborum (QL) block for major abdominal surgery. These blocks are routinely administered as a continuous catheter technique in order to extend the duration of postoperative analgesia. Although rare, continuous nerve block techniques carry risks and limitations, including catheter dislodgement, migration, kinking and leaking at the site, bleeding, and infection. They are also much more expensive to perform and maintain than single-injection nerve blocks at this institution. Perioperative intravenous (IV) lidocaine is one of the safest local anesthetics, and its use has been shown to provide analgesia and reduce opioid requirements. Furthermore, it has been hypothesized that part of the analgesic efficacy of continuous peripheral nerve blocks may be due to the systemic effects of the local anesthetic infused at the site. Therefore, it is possible that the combination of a single block followed by an infusion of IV lidocaine may provide the same benefits as a continuous nerve block at a lower cost. The purpose of this study is to show that a single block technique plus IV lidocaine is non-inferior to a continuous block technique. For the purpose of this study we chose two surgical models--VATS and major abdominal surgery--and ESP and QL blocks, respectively. The study will be conducted as a prospective, randomized (1:1), open-label, active-comparator, noninferiority trial. The study will prospectively investigate the efficacy of continuous block versus single block plus IV lidocaine infusion for postoperative pain management in patients undergoing primary unilateral VATS or primary major abdominal surgery.
Detailed description
After obtaining a signed informed consent, participating patients will be randomized by computer generated random numbers to either the control group to receive continuous Erector Spinae Plane block (in the case of thoracic surgery) or continuous Quadratus Lumborum block (in the case of abdominal surgery), or the treatment group to receive single shot Erector Spinae Plane block (in the case of thoracic surgery) or single shot Quadratus Lumborum block (in the case of abdominal surgery) with postoperative intravenous lidocaine infusion. Subjects will be randomized in a 1:1 ratio. Randomization will take place via an opaque envelope containing the treatment group allocation that will be given to the anesthesiologist performing the block after informed consent is signed. Procedures will take place in the UPMC Shadyside pre-operative block area. The expected duration of nerve block procedures is 10-20 minutes. If the patient is randomized to the continuous nerve block group and is undergoing thoracic surgery, an anesthesiologist on the Acute Interventional Perioperative Pain Service (AIPPS) will administer the block with this approach: Continuous ESP Block Approach: The patient will be positioned in seated position with side or sides to be blocked marked. The T5 spinous process will be identified by palpation starting with C7 and continuing caudad. C7 is the most prominent spinous process anatomically. The T5 spinous process will be marked with a marking pen. The block area will be cleaned using 2% chlorhexidine solution. The entire block procedure is performed under strict aseptic technique. An ultrasound probe covered in a sterile probe cover will be placed at the T5 spinous process in a cephalad to caudad orientation and moved lateral until the T5 transverse process is identified. 1-2ml of 1% lidocaine will be administered just above the ultrasound probe for local skin infiltration. An 18 gauge Tuohy needle will then be inserted in plane in a cephalad to caudad direction under ultrasound visualization until the tip of the needle touches the T5 transverse process. The T5 transverse process is the anatomical target for this block. 20ml of 0.5% ropivacaine will then be injected using slow fractionated injection, aspirating every 5ml to ensure the needle tip is not intravascular. Local anesthetic spread in the appropriate plane will be confirmed with ultrasound. Once injection is complete, a 20 gauge nonstimulating catheter will be inserted through the Tuohy needle. Catheter tip placement will be confirmed with ultrasound. If bilateral blocks are to be performed, the procedure will then be repeated on the contralateral side. Upon patient arrival to PACU, a continuous infusion of 0.25% lidocaine at 10ml/hr per side blocked via ESP catheter will be initiated and continued for 72 hours or until 12 hours prior to patient discharge. If the patient is randomized to the continuous nerve block group and is undergoing abdominal surgery, an anesthesiologist on the Acute Interventional Perioperative Pain Service (AIPPS) will administer the block with this approach: Continuous QL Block Approach: The patient will be positioned in lateral decubitus position with the side to be blocked facing up and the side or sides to be blocked marked. The block area will be cleaned using 2% chlorhexidine solution. The entire block procedure is performed under strict aseptic technique. An ultrasound probe covered in a sterile probe cover will be placed transversally between the iliac crest and the costal margin at the level of the anterior axillary line and the three muscles of the anterolateral abdominal wall (external oblique, internal oblique and transversus abdominis) will be identified. The probe will then be moved posteriorly until the transversus abdominis muscle (TAM) tapers off into its aponeurosis approximately at the level of the posterior axillary line, and posteriorly to this the intersection of the transversalis fascia with the lateral side of the QL muscle will be identified. An 18 gauge Tuohy needle will then be inserted in plane in an anterior to posterior direction until the tip of the needle is visualized at the intersection of the transversalis fascia with the lateral side of the QL muscle. The intersection of the transversalis fascia with the lateral side of the QL muscle is the anatomical target for this block. Once the initial injection of local anesthetic is complete, a 20 gauge nonstimulating catheter will be inserted through the Tuohy needle. Catheter tip placement will be confirmed with ultrasound. If bilateral blocks are to be performed, the patient will be repositioned, the area to be blocked will be cleaned and prepared in a strict aseptic fashion as described above, and the procedure will then be repeated on the contralateral side. Upon patient arrival to PACU, a continuous infusion of 0.25% Lidocaine at 10ml/hr per side blocked via QLB catheter will be initiated and continued for 72 hours or until 12 hours prior to patient discharge. If the patient is randomized to the single block plus IV lidocaine group and is undergoing thoracic surgery, an anesthesiologist on the Acute Interventional Perioperative Pain Service (AIPPS) will administer the block with this approach: Single Shot ESP Block with Postoperative IV Lidocaine Approach: The same technique described for the CESP will be used except that in this case a single ESP block will be performed. A 22 gauge Tuohy needle will be used to perform these blocks. After the proper positioning of the needle 20ml of 0.5% ropivacaine plus, 4mg dexamethasone, plus 30mcg dexmedetomidine will be deposited. In the recovery room an infusion of IV lidocaine at 50mg/hr for be initiated for 72 hours or until 12 hours prior to patient discharge. If the patient is randomized to the single block plus IV lidocaine group and is undergoing abdominal surgery, an anesthesiologist on the Acute Interventional Perioperative Pain Service (AIPPS) will administer the block with this approach: Single Shot QL Block with Postoperative IV Lidocaine Approach: The same technique described for the CQL will be used except that a single QL block will be performed. A 22 gauge Tuohy needle will be used to perform these blocks. After the proper positioning of the needle 20ml of 0.5% ropivacaine plus, 4mg dexamethasone, plus 20mcg dexmedetomidine per injection site (30mcg if unilateral block only) will be deposited. Upon patient arrival to PACU, a continuous infusion of intravenous lidocaine at 50mg/hr will be initiated and continued for 72 hours or until 12 hours prior to patient discharge. Anesthetic Management: Both treatment groups will receive the standard anesthetic technique and multimodal analgesic technique at our institution, including preoperative gabapentin 300mg PO and acetaminophen 1000mg PO, intraoperative IV propofol infusion-based general anesthetic combined with sub-anesthetic dose IV ketamine infusion, IV dexmedetomidine infusion, IV acetaminophen, and avoidance of intraoperative opioids. Postoperative pain management will also follow standard protocol, using IV hydromorphone (0.2-0.3 mg) and PO oxycodone (5-10 mg) on request by the patient for moderate to severe pain (VAS \>5), scheduled ketamine 20-50mg PO q 8hrs for 48 hours, scheduled acetaminophen 1000mg IV or PO q 6hrs, scheduled gabapentin 100-300mg PO at bedtime, and dexmedetomidine infusion 0.2mcg/kg/hr IV for 24 hours if the patient is located in the Intensive Care Unit. After surgery, the patient will be followed by the blinded research team for incidence of adverse events, as well as the collection of the primary and secondary outcome measures. Pain assessment will be done by nurses in the PACU and on the floor using Numeric Pain Rating Scale, with 0 meaning no pain and 10 meaning worst possible pain. Opioid medication consumption, pain scores, local anesthetic medication consumption, serum lidocaine levels, and adverse effects will be recorded on worksheets included in patient research folders, with each study participant having their own research folder identified only by randomly assigned patient study number. The research coordinator responsible for data collection will remain blinded to the patient's group allocation, and will not become unblinded during the data collection process because data will be collected from the patient's medical record and will not involve physically observing the patient (which would otherwise result in unblinding since the presence or absence of a perineural catheter and patient pump status would make the group allocation obvious). However, this information will not be obtainable when collecting data from the medical record. It is not possible to blind nursing staff or the patient to the patient's group allocation because the presence or absence of a visible perineural catheter will make the group allocation obvious.
Interventions
To be administered to subjects in the active comparator group receiving primary unilateral thoracic surgery.
To be administered to subjects in the active comparator group receiving primary major abdominal surgery.
To be administered to subjects in the experimental group receiving primary unilateral thoracic surgery.
To be administered to subjects in the experimental group receiving primary major abdominal surgery.
To be given postoperatively as a continuous infusion at a dose of 50 mg/hr in the experimental group.
To be used in both treatment arms as nerve block initial bolus injection.
To be used in the experimental arm as a nerve block adjuvant to promote prolonged single block duration, as is standard of care in this institution.
To be used in the experimental arm as a nerve block adjuvant to promote prolonged single block duration, as is standard of care in this institution.
To be used perineurally as a 0.25% solution in the active comparator group at a rate of 10 ml/hr per perineural catheter.
Sponsors
Study design
Masking description
For study participants, the investigator placing the block will record in the narrative that this patient is a study participant and received Paravertebral block with ESP approach or this patient is a study participant and received TAP block with QL approach. By documenting blocks in this way, the research team member collecting the data will be blinded to whether the patient received continuous block with 0.5% ropivacaine, or single block with 0.5% ropivacaine, dexamethasone, and dexmedetomidine.
Intervention model description
Two groups of patients will be studied simultaneously. One group will receive continuous peripheral nerve blocks and the other group will receive single blocks plus postoperative intravenous lidocaine infusion.
Eligibility
Inclusion criteria
* 18-90 years old * Primary unilateral VATS or major abdominal surgery * BMI 20-36, weight ≥ 50kg * Male and Female * All races
Exclusion criteria
* Patient refusal * Inpatient status at the time of surgery * ASA class 4 or greater * Pregnancy * Non-English speaking or inability to participate in the study * Patients with coagulopathy or on therapeutic anticoagulation * Chronic steroid use * Opioid use disorder * Contraindication to performing any of the proposed blocks - active infection at the block site, systemic infection, allergy to local anesthetic medications * Patients undergoing second surgery or urgent/emergent surgery * Patients weighing \< 50kg * History of chronic pain and/or opioid tolerant * Anticipated requirement for patient-controlled analgesia (PCA) * Allergy or intolerance to any medication specified in the study protocol or postoperative pain management regimen * Liver disease
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Opioid Consumption After Surgery | 24 hours after surgery | Opioids will be converted to oral morphine equivalents |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Pain After Surgery | 6 hours after surgery | By numeric pain rating scale, 0 = no pain and 10 = worst possible pain |
| Local Anesthetic Consumption After Surgery | 12 hours after surgery | Local anesthetic consumption after surgery is reported in mg of lidocaine |
| Opioid Consumption After Surgery | 48 hours after surgery | Opioids will be converted to oral morphine equivalents |
| Total Hospital Length of Stay | From admission to discharge, on average 1-4 days | Hospital length of stay is measured in days from admission until discharge. |
| Incidence of Adverse Events | From time of surgery to discharge, on average 1-4 days | Nausea and vomiting requiring treatment, hypotension, or bradycardia or tachycardia |
| Serum Lidocaine Level | 24 hours after surgery | Serum lidocaine level measured via a blood test. Lidocaine has a therapeutic drug range of 1.5 to 5.0 mcg/mL. |
Countries
United States
Participant flow
Pre-assignment details
For 3 patients under the abdominal portion of this study, Erector Spinae Blocks were performed rather than Quadratus Lumborum Blocks. There are various anatomic reasons why a different block would be considered when performing the actual block. This study was analyzing Quadratus Lumborum Blocks for abdominal surgery, as such, the results from the patients who had Erector Spinae Blocks for abdominal surgery were excluded.
Participants by arm
| Arm | Count |
|---|---|
| Continuous Nerve Blocks A total of 7 subjects equally distributed to either continuous Erector Spinae Plane block for unilateral thoracic surgery, or continuous Quadratus Lumborum block for major abdominal surgery. Patients in this group will receive 20ml 0.5% ropivacaine per block performed after positioning of the needle followed by continuous perineural infusion of 0.25% lidocaine (10ml/hr) beginning in the post-anesthesia care unit (PACU) and continued for 72 hours or until 12 hours prior to patient discharge, whichever comes first, which is standard of care at this institution.
Continuous Erector Spinae Plane Nerve Block: To be administered to subjects in the active comparator group receiving primary unilateral thoracic surgery.
Continuous Quadratus Lumborum Nerve Block: To be administered to subjects in the active comparator group receiving primary major abdominal surgery.
Ropivacaine 0.5% Injectable Solution: To be used in both treatment arms as nerve block initial bolus injection.
Lidocaine: To be used perineurally as a 0.25% solution in the active comparator group at a rate of 10 ml/hr per perineural catheter. | 7 |
| Single Nerve Blocks Plus IV Lidocaine Infusion A total of 7 subjects equally distributed to either Erector Spinae Plane block for unilateral thoracic surgery, or Quadratus Lumborum block for major abdominal surgery, will be included . Patients in this group will receive 20ml 0.5% ropivacaine, 4mg dexamethasone, and 20mcg dexmedetomidine (30mcg if only one block is performed) per block after proper positioning of the Tuohy needle. Upon patient arrival in the recovery room a continuous infusion of IV lidocaine 50 mg /hr will be started and continued for 72 hours or until 12 hours prior to patient discharge, whichever comes first, which is standard of care at this institution.
Single Erector Spinae Plane Nerve Block: To be administered to subjects in the experimental group receiving primary unilateral thoracic surgery.
Single Quadratus Lumborum Nerve Block: To be administered to subjects in the experimental group receiving primary major abdominal surgery.
Lidocaine IV: To be given postoperatively as a continuous infusion at a dose of 50 mg/hr in the experimental group.
Ropivacaine 0.5% Injectable Solution: To be used in both treatment arms as nerve block initial bolus injection.
Dexamethasone: To be used in the experimental arm as a nerve block adjuvant to promote prolonged single block duration, as is standard of care in this institution.
Dexmedetomidine: To be used in the experimental arm as a nerve block adjuvant to promote prolonged single block duration, as is standard of care in this institution. | 7 |
| Total | 14 |
Baseline characteristics
| Characteristic | Total | Single Nerve Blocks Plus IV Lidocaine Infusion | Continuous Nerve Blocks |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 10 Participants | 4 Participants | 6 Participants |
| Age, Categorical Between 18 and 65 years | 4 Participants | 3 Participants | 1 Participants |
| Age, Continuous | 68.64 years STANDARD_DEVIATION 7.42 | 65.43 years STANDARD_DEVIATION 7.72 | 71.86 years STANDARD_DEVIATION 5.96 |
| Race and Ethnicity Not Collected | 0 Participants | — | — |
| Region of Enrollment United States | 7 participants | 7 participants | 7 participants |
| Sex: Female, Male Female | 4 Participants | 2 Participants | 2 Participants |
| Sex: Female, Male Male | 10 Participants | 5 Participants | 5 Participants |
| Weight (kg) | 81.50 kilograms STANDARD_DEVIATION 12.23 | 84.71 kilograms STANDARD_DEVIATION 14.9 | 78.29 kilograms STANDARD_DEVIATION 8.85 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 7 | 0 / 7 |
| other Total, other adverse events | 1 / 7 | 0 / 7 |
| serious Total, serious adverse events | 0 / 7 | 1 / 7 |
Outcome results
Opioid Consumption After Surgery
Opioids will be converted to oral morphine equivalents
Time frame: 24 hours after surgery
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Continuous Nerve Blocks | Opioid Consumption After Surgery | 34.93 OME | Standard Deviation 31.32 |
| Single Nerve Blocks Plus IV Lidocaine Infusion | Opioid Consumption After Surgery | 46.50 OME | Standard Deviation 33.37 |
Incidence of Adverse Events
Nausea and vomiting requiring treatment, hypotension, or bradycardia or tachycardia
Time frame: From time of surgery to discharge, on average 1-4 days
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Continuous Nerve Blocks | Incidence of Adverse Events | 0 Participants |
| Single Nerve Blocks Plus IV Lidocaine Infusion | Incidence of Adverse Events | 0 Participants |
Local Anesthetic Consumption After Surgery
Local anesthetic consumption after surgery is reported in mg of lidocaine
Time frame: 12 hours after surgery
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Continuous Nerve Blocks | Local Anesthetic Consumption After Surgery | 574.29 mg | Standard Deviation 179.73 |
| Single Nerve Blocks Plus IV Lidocaine Infusion | Local Anesthetic Consumption After Surgery | 600 mg | Standard Deviation 0 |
Local Anesthetic Consumption After Surgery
Local anesthetic consumption after surgery is reported in mg of lidocaine
Time frame: 24 hours after surgery
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Continuous Nerve Blocks | Local Anesthetic Consumption After Surgery | 1096.07 mg | Standard Deviation 330.01 |
| Single Nerve Blocks Plus IV Lidocaine Infusion | Local Anesthetic Consumption After Surgery | 1139.29 mg | Standard Deviation 160.63 |
Local Anesthetic Consumption After Surgery
Local anesthetic consumption after surgery is reported in mg of lidocaine
Time frame: 48 hours after surgery
Population: One patient in the single nerve block plus IV lidocaine infusion group was discharged well before 48 hours, so their data was not included.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Continuous Nerve Blocks | Local Anesthetic Consumption After Surgery | 1973.57 mg | Standard Deviation 717.7 |
| Single Nerve Blocks Plus IV Lidocaine Infusion | Local Anesthetic Consumption After Surgery | 2308.33 mg | Standard Deviation 149.72 |
Local Anesthetic Consumption After Surgery
Local anesthetic consumption after surgery is reported in mg of lidocaine
Time frame: 72 hours after surgery
Population: Two patients in the single nerve block plus IV lidocaine infusion group were discharged well before 72 hours, so their data was not included.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Continuous Nerve Blocks | Local Anesthetic Consumption After Surgery | 2721.79 mg | Standard Deviation 896.91 |
| Single Nerve Blocks Plus IV Lidocaine Infusion | Local Anesthetic Consumption After Surgery | 2570.0 mg | Standard Deviation 499.5 |
Opioid Consumption After Surgery
Opioids will be converted to oral morphine equivalents
Time frame: 48 hours after surgery
Population: One patient from the single nerve block plus IV lidocaine infusion group was not included because they were discharged before 48 hours and opioids were not recorded as an outpatient.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Continuous Nerve Blocks | Opioid Consumption After Surgery | 61.5 OME | Standard Deviation 54.06 |
| Single Nerve Blocks Plus IV Lidocaine Infusion | Opioid Consumption After Surgery | 84.75 OME | Standard Deviation 65.57 |
Opioid Consumption After Surgery
Opioids will be converted to oral morphine equivalents
Time frame: 72 hours after surgery
Population: Two patients from the single nerve block plus IV lidocaine infusion group was not included because they were discharged before 72 hours and opioids were not recorded as an outpatient.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Continuous Nerve Blocks | Opioid Consumption After Surgery | 88.57 OME | Standard Deviation 60.24 |
| Single Nerve Blocks Plus IV Lidocaine Infusion | Opioid Consumption After Surgery | 128.1 OME | Standard Deviation 150.29 |
Pain After Surgery
By numeric pain rating scale, 0 = no pain and 10 = worst possible pain
Time frame: 6 hours after surgery
Population: One patient in the continuous nerve block group did not have pain scores recorded due to lethargy. They were not included in the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Continuous Nerve Blocks | Pain After Surgery | 6.17 score on a scale | Standard Deviation 3.25 |
| Single Nerve Blocks Plus IV Lidocaine Infusion | Pain After Surgery | 6.14 score on a scale | Standard Deviation 1.77 |
Pain After Surgery
By numeric pain rating scale, 0 = no pain and 10 = worst possible pain
Time frame: 72 hours after surgery
Population: Three patients in the single nerve block plus IV lidocaine infusion group were discharged prior to 72 hours and did not have a pain score recorded at that time.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Continuous Nerve Blocks | Pain After Surgery | 5.36 score on a scale | Standard Deviation 1.75 |
| Single Nerve Blocks Plus IV Lidocaine Infusion | Pain After Surgery | 5.0 score on a scale | Standard Deviation 1.83 |
Pain After Surgery
By numeric pain rating scale, 0 = no pain and 10 = worst possible pain
Time frame: 12 hours after surgery
Population: One patient in the continuous nerve block group did not have pain scores recorded due to lethargy. They were not included in the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Continuous Nerve Blocks | Pain After Surgery | 6.17 score on a scale | Standard Deviation 3.67 |
| Single Nerve Blocks Plus IV Lidocaine Infusion | Pain After Surgery | 6.07 score on a scale | Standard Deviation 2.83 |
Pain After Surgery
By numeric pain rating scale, 0 = no pain and 10 = worst possible pain
Time frame: 24 hours after surgery
Population: One patient in the continuous nerve block group did not have pain scores recorded due to lethargy. They were not included in the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Continuous Nerve Blocks | Pain After Surgery | 4.5 score on a scale | Standard Deviation 2.17 |
| Single Nerve Blocks Plus IV Lidocaine Infusion | Pain After Surgery | 6.43 score on a scale | Standard Deviation 2.88 |
Pain After Surgery
By numeric pain rating scale, 0 = no pain and 10 = worst possible pain
Time frame: 48 hours after surgery
Population: One patient in the single nerve block plus IV lidocaine infusion group was discharged prior to 48 hours and did not have a pain score recorded at that time.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Continuous Nerve Blocks | Pain After Surgery | 5.86 score on a scale | Standard Deviation 2.67 |
| Single Nerve Blocks Plus IV Lidocaine Infusion | Pain After Surgery | 4.83 score on a scale | Standard Deviation 3.37 |
Serum Lidocaine Level
Serum lidocaine level measured via a blood test. Lidocaine has a therapeutic drug range of 1.5 to 5.0 mcg/mL.
Time frame: 48 hours after surgery
Population: Serum collection was not standard of care and was not collected for all participating subjects
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Single Nerve Blocks Plus IV Lidocaine Infusion | Serum Lidocaine Level | 5.8 mcg/mL |
Serum Lidocaine Level
Serum lidocaine level measured via a blood test. Lidocaine has a therapeutic drug range of 1.5 to 5.0 mcg/mL.
Time frame: 72 hours after surgery
Population: Serum collection was not standard of care and was not collected for all participating subjects
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Single Nerve Blocks Plus IV Lidocaine Infusion | Serum Lidocaine Level | 1.5 mcg/mL |
Serum Lidocaine Level
Serum lidocaine level measured via a blood test. Lidocaine has a therapeutic drug range of 1.5 to 5.0 mcg/mL.
Time frame: 24 hours after surgery
Population: Serum collection was not standard of care and was not collected for all participating subjects
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Continuous Nerve Blocks | Serum Lidocaine Level | 2.5 mcg/mL | Standard Deviation 0 |
Total Hospital Length of Stay
Hospital length of stay is measured in days from admission until discharge.
Time frame: From admission to discharge, on average 1-4 days
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Continuous Nerve Blocks | Total Hospital Length of Stay | 9.04 days | Standard Deviation 6.5 |
| Single Nerve Blocks Plus IV Lidocaine Infusion | Total Hospital Length of Stay | 4.94 days | Standard Deviation 3.71 |