Appendix A: Characteristics of studies included for analysis

Buckenmaier 2010 Results ( cPNB/ssPNB ) Methods Prospective, randomized, double-blind comparative

trial. Enrolled and assigned to treatment group by Investigational Pharmacy team member. Anesthesiologists, patients, and assessors remained blinded. Study solution prepared by Investigational Pharmacy.

Participants 73 adults, ASA status not specified, undergoing unilateral breast surgery for early breast cancer. 94 patients enrolled, 21 excluded, 73 analyzed.

N (0.2% Ropivacaine infusion) : 26N (0.1% Ropivacaine infusion): 26N (Normal saline): 21 0.2% and 0.1% Ropivacaine groups combined for our analysis.

Block Single paravertebral injections at T1 and T6 with 5ml ropivacaine 0.1%. T3 block with 0.3 ml/kg ropivacaine 0.5% followed by catheter placement at T3, infusion at 10ml/hr 0.1% ropivacaine, 0.2% ropivacaine, or normal saline for 72 hours. Block used for surgical anesthesia.

2 regional anesthesia complications: one Horner’s syndrome, one with arm numbness resolving in < 1 week (treatment group not specified).

Outcomes Evaluations performed at baseline and on days 1, 3, 5, and 7 postoperatively. Evaluation included worst postoperative pain (VAS 0-10), Perioperative Profile of Mood State (POMS-SV, scale 0-120), McGill pain questionnaire score (scale 0-78), symptom distress score (SDS, scale 10-50), proportion of patients with nausea and vomiting scores > 1 (part of McCorkle SDS), return to regular diet, return to activities of daily living (ADL), return to full employment, and total opioid use through POD 7.

McGill Pain Questionnaire rates sensory, affective, and evaluative descriptors of subjective appraisal of pain and quantification of pain. The word in each subclass implying the least pain = 1, and so on (range 0-78). POMS = 65 items based on a 5-point scale ranging from 0 (not at all) to 4 (extremely) describing six mood states: tension-anxiety (T), depression-dejection (D), anger-hostility (A), vigor-activity (V), fatigue-inertia (F), and confusion-bewilderment (C). POMS-SV (shortened version), was used.McCorkle SDS = 10-item scale measuring degree of distress with 10 symptoms: nausea, mood, appetite, insomnia, pain, mobility, fatigue, bowel pattern, concentration, and appearance.

( 0.2% Ropivacaine/0.1% Ropivacaine/NS ) Worst postoperative VAS POD 1•: 2.5/2.7/2.8*Worst postoperative VAS POD 3•: 2.2/2.4/1.8Worst postoperative VAS POD 5•: 1.8/2.5/1.7Worst postoperative VAS POD 7•: 1.2/2.7/1.9Total mg morphine equivalent used•: 41.4/43.7/36.2McGill score POD 1 •: 6/5/5McGill score POD 3•: 5/6/4McGill score POD 5•: 5/7/4 McGill score POD 7•: 3/9/5McCorkle SDS score POD 1•: 20/19/20McCorkle SDS score POD 3•: 16/17/18McCorkle SDS score POD 5•: 16/17/16McCorkle SDS score POD 7•: 14/17/16POMS-SV score POD 1•: 18/20/19POMS-SV score POD 3•: 17/20/18POMS-SV score POD 5•: 17/19/20POMS-SV score POD 7•: 16/21/20% nausea and vomiting scores > 1 POD 1: 22/46/24% nausea and vomiting scores > 1 POD 3: 23/22/23% nausea and vomiting scores > 1 POD 5: 16/18/10% nausea and vomiting scores > 1 POD 7: 8/26/24% returning to regular diet immediately: 96/96/90% returning to regular diet POD 1: 4/4/10% returning to ADL immediately: 8/12/0% returning to ADL week 1: 92/81/100% returning to ADL week 2: 0/8/0% returning to full employment week 1: 35/46/40% returning to full employment week 2: 50/29/25% returning to full employment week 3: 15/17/10% returning to full employment > 3 weeks: 0/8/25Conversion from RA to GA: 3/2/4

Quality Score(13 max.)

11 -1 block technique (catheter thread after SS block) -1 intent to treat (5 patients excluded after randomization)

Notes 5 subjects excluded post-randomization for the following reasons:

1 -refused operation1- sought care at different institution 1- became ineligible due to chemotherapy1- CPVB discontinued postoperatively due to leaking catheter 1- unreliable dataMultimodal analgesia included scheduled Acetaminophen and an NSAID.

Elliot 2010 Results ( cPNB/ssPNB ) Methods Prospective, double-blind, comparative trial.

Patients, anesthesiologists and assessors were blinded. Randomization described as sequential sealed envelopes.

Participants 54 patients, ASA unspecified, undergoing ankle and hindfoot surgery.

N (cPNB) = 27N (ssPNB) = 27

Block GA was induced prior to block. Initial bolus 0.5% bupivacaine 20ml, then popliteal catheter was thread. ssPNB group received continuous saline infusion and cPNB group received 0.25% bupivacaine 4ml/hr with 1ml/hr patient controlled bolus for 72 hours. All patients also received saphenous block at the level of the knee with 0.5% bupivacaine 10ml.

Outcomes Subjects recorded VAS pain scores three times daily for 72 hours postoperatively. Requirement for supplemental opioid analgesia and complications were recorded.

mg morphine used on POD 0†: 10/10mg morphine used on POD 1†: 10/15mg morphine used on POD 2†:10/20*mg morphine used on POD 3†: 7.5/10*total mg morphine used POD 1-3†: 30/52.5*VAS POD 0†: 1.2/1.0VAS POD 1†: 1.7/3.7*VAS POD 2†: 1.3/2.8*VAS POD 3†: 1.1/2.6*Nights as inpatient†: 1/2

Quality Score(13 max.)

8 -3: Randomization (methods not described).-1: anesthetic care (care in study and control group not described or compared).-1: technique (catheter thread after SS block).

Notes No major complications as a result of the block. One patient in placebo group experienced accidental dislodgement of the catheter after 48 hours.

Fredrickson 2010 Results ( cPNB, ssPNB ) Methods Prospective, randomized, comparative trial.

Computerized randomization. Patient and anesthesiologist were not blinded. Surgeon and assessor were blinded.

Participants 68 ASA I-II patients undergoing arthroscopic subacromial decompression, lateral clavicle excision, or stabilization.

N (cPNB) = 31N (ssPNB) = 30

Block Ultrasound guided interscalene block with 30ml ropivacaine 0.5% through catheter for both groups. Surgery under general anesthesia. Catheter placement preoperatively. Randomization postoperatively, then catheter removed from patients in SS group. The cPNB group received ropivacaine 0.2% at 2ml/hr with 5ml per hour demand dose for 48 hours.

Outcomes Patients questioned on POD 1 and 2 for numeric pain score, tramadol consumption, arm numbness (0 = no numbness, 10 = very numb), arm weakness (0 = no weakness, 10 = 100% weak), numb patient satisfaction (0 = very unsatisfied, 10 = 100% satisfied), proportion of night slept (0 = no sleep, 100 = 100% sleep), and adverse effects.

Worst pain with movement POD 1 †: 2/4*Worst pain with movement POD 2 †: 3/5Worst pain at rest POD 1 †: 1/2*Worst pain at rest POD 2 †: 4/3Average pain POD 1 †: 1/2*Average pain POD 2 †: 2/2Tramadol tablets required POD 1†: 0/1*Tramadol tablets required POD 2†: 0/1*# taking 0 tramadol tablets POD 1: 24/10# taking 1 tramadol tablet POD 1: 5/10# taking ≥ 2 tramadol tablets POD 1: 2/10# taking 0 tramadol tablets POD 2: 23/13# taking 1 tramadol tablets POD 2: 2/5# taking ≥ 2 tramadol tablets POD 2: 6/12Proportion of night slept POD 1†: 70/45Proportion of night slept POD 2†: 80/75# with nausea on POD 1: 4/8# with nausea on POD 2: 5/4Arm numbness score on POD 1†: 9/8.5**Arm numbness score on POD 2†: 3/0**Arm weakness score on POD 1†: 9/7Arm weakness score on POD 2†: 6/5Satisfaction score†: 9/9# new neurologic symptoms reported on POD 10: 1/3# patients reporting pain > 6 by NRS on POD 0: 1/5# with NRS > 6 on POD 1: 1/5

Quality Score(13 max.)

10 -1: block technique (no true SS group).-2: blinding (anesthesiologists and patients not blinded).

Notes One patient in SS group required block replacement in PACU. One patient in SS group was hospitalized for 2 nights with severe pain and was treated with supplemental IV opioid until a perineural catheter was placed on POD 2, thereafter no opioid was needed.Multimodal analgesia included scheduled acetaminophen and diclofenac.

The proportion of patients undergoing specific procedure types was comparable:Subacromial decompression: 5/6Excision of lateral clavicle: 4/4Labral repair: 22/20

Frassanito 2009 Results ( cPNB/ssPNB ) Methods Prospective, randomized comparative trial.

Randomization by computer generated table.Anesthesiologists and patients unblinded. Assessor not identified in study.

Participants 44 patients, ASA I-III, undergoing total knee arthroplasty under regional anesthesia with sedation.

N (cPNB) = 22N (ssPNB) = 22

Block PNS guided lumbar plexus block with 0.6% ropivacaine as single injection of 30ml versus single injection of 30ml followed by catheter placement and infusion of ropivacaine 0.2% at 10ml/hr for 48 hr. All patients received single injection sciatic nerve block.

Outcomes Assessed in PACU; on arrival to ward; and at 6, 12, 24, 36, 48, and 72 hours after the start of surgery. Noted VAS score, tramadol consumption, nausea/vomiting, motor power, and ambulation.Primary endpoint was ability of block to provide surgical anesthesia for TKA.

Pain (VAS) at 6 hr•: 0.4/0Pain (VAS) at 12 hr•: 1.7/1.6Pain (VAS) at 24 hr•: 3.7/5.1Pain (VAS) at 36 hr•: 4.8/3.1Pain (VAS) at 48 hr•: 3.2/1.7Total mg tramadol consumption •: 185/236

# requiring intraoperative remifentanil infusion: 5/3Time to perform block•: 11.3/10.9% of patients with nausea•: 18/27% of patients with vomiting•: 4/13# bilateral block: 2/2

Quality Score(13 max.)

9 -1: technique (catheter thread after SS block).-3: blinding (methods not described).

Notes 2 patients in each group experienced bilateral spread of block. One case was associated with SBP < 90mm Hg. Multimodal analgesia included scheduled acetaminophen.

Mariano 2009 Results ( cPNB/ssPNB ) Methods Prospective, randomized, double-blind comparative

trial. Randomization by computer generated table. Identical study solutions prepared by Investigational Pharmacy. Investigators, patients, and clinical staff unaware of group allocation.

Participants 32 subjects undergoing shoulder surgery were enrolled. Two excluded when unable to obtain motor response with PNS at time of block placement.

N (cPNB) = 15N (ssPNB) = 15

Block Interscalene block performed with 40ml ropivacaine 0.5% through the catheter in both groups. Continuous infusion of ropivacaine 0.2% or NS at 8ml/hr + 4ml bolus every 30 minutes until 400ml solution used or no later than afternoon of POD 2. All subjects underwent general anesthesia for surgery.

Outcomes Subjects were telephoned on the evening of surgery and each postoperative afternoon through POD 3. Outcomes were VAS pain score (scale 0-10), mg oxycodone consumed, sleep quality, satisfaction (0 = not satisfied, 10 = very satisfied).

Average pain on POD 0†: 0/0Average pain on POD 1†: 0/3*Average pain on POD 2†: 0/4*Average pain on POD 3†: 2/3Worst pain on POD 0†: 0/0Worst pain on POD 1†: 4/7.5*Worst pain on POD 2†: 2.8/8*Worst pain on POD 3†: 5/6Least pain on POD 0†: 0/0Least pain on POD 1†: 0/3*Least pain on POD 2†: 0/1*Least pain on POD 3†: 2/1Satisfaction with analgesia†: 10/7*# awakenings per night POD 0†: 0/0*# awakenings per night POD 1†: 0/0*# awakenings per night POD 2†: 0/0Mg oxycodone consumed POD 0†: 0/0Mg oxycodone consumed POD 1†: 0/20*Mg oxycodone consumed POD 2†: 0/30*Mg oxycodone consumed POD 3†: 25/15

Quality Score(13 max.)

12 -1: technique (no true SS group).

Notes 2 patients receiving continuous infusion experienced mild shortness of breath on POD 1 which resolved after decreasing the infusion from 8 to 4 ml/hr.1 patient in ssPNB group requested disenrollment due to catheter site pain which improved after

catheter removal. 1 patient returned to surgical center for discomfort at site when attempting to remove catheter. The catheter was removed by anesthesiologist under local without complication.Multimodal analgesia included ketorolac.

Williams (2009, 2007, 2006) Results ( cPNB/ssPNB ) Methods Prospective, randomized, double-blind comparative

trial. Randomization assignments generated by computer program. Anesthesiologists, patients, and assessors remained blinded.

Participants 270 patients, ASA I-II, undergoing ACL reconstruction were recruited, 233 were analyzed. Randomized into levobupivacaine bolus and infusion, levobupivacaine bolus plus saline infusion, or saline bolus with saline infusion.

N (cPNB) = 76N (ssPNB) = 79Control group = 78 (For our analysis the control group was inapplicable).

Block Femoral nerve block performed in PACU after spinal and deep sedation for knee surgery. Initial bolus 0.25% levobupivacaine 30ml. Infusion of 0.25% levobupivacaine or NS at 5ml/hr until 270ml reservoir depleted (22 hours).

Nerve stimulation guided block quadriceps twitch at 0.3-0.5mA, blinded bolus syringe administered catheter thread and secured infusion device attached.

Outcomes 2009Retrospective analysis of prospectively collected data from 2006.2007 (“Rebound”)Retrospective analysis of prospectively collected data from 2006. Increasing nerve block duration did not increase rebound pain (defined as [time at which patient reported block was not providing pain relief – recorded time of nerve block insertion on day of surgery])

2007 (“Nausea, Vomiting, Sleep and Restfulness”)Retrospective analysis of prospectively collected data from 2006. QoR-40 used as measure of sleep and restfulness. Likert-type responses were combined into dichotomous variables for analysis.

Original Prospective Trial 2006Patients were called to obtain NRS pain scores at rest and with movement on POD 1-4 and 7. Incidence of PONV determined by chart review; criteria were administration of antiemetic or RN documentation in PACU or Phase 2 recovery.

2009Nerve block treatment group was not significantly associated with SF-36 or KOS-ADLS outcomes.2007 (“Rebound”)Block duration (hours) •: 59/37*2007 (“Nausea, Vomiting, Sleep and Restfulness”)% experiencing “any moderate pain” POD 1: 73/80% experiencing “any moderate pain” POD 2: 82/83% experiencing “any moderate pain” POD 3: 74/76% experiencing “any moderate pain” POD 4: 64/73% experiencing “any severe pain” POD 1: 19/31% experiencing “any severe pain” POD 2: 26/41% experiencing “any severe pain” POD 3: 25/36% experiencing “any severe pain” POD 4: 27/232006# PONV on day of surgery: 2/3# needing no opioid in PACU or Phase 2 recovery: 62/61Mg oxycodone given prior to discharge•: 11.1/10.8Mg oxycodone consumed POD 1•: 30/33Mg oxycodone consumed POD 2•: 25/28Mg oxycodone consumed POD 3•: 19/20Mg oxycodone consumed POD 4•: 14/13Cumulative mg oxycodone used POD 1-4•: 88/94Pain by NRS with movement POD 1†: 2/3*Pain by NRS with movement POD 2†: 2/4*NNTT with cPNB vs. ssPNB = 5 (to avoid 1 patient experiencing NRS >3 w/ movement on POD 1).NNTT with cPNB vs. ssPNB = 7 (to avoid 1 patient experiencing NRS ≥ 5 w/ movement on POD 1).NNTT with cPNB vs. ssPNB = 5 (to avoid 1 patient experiencing NRS > 3 on POD 2).NNTT with cPNB vs. ssPNB = 7 (to avoid 1 patient experiencing NRS ≥ 5 on POD 2).% Absolute risk reduction, NRS > 3 w/ movement on POD 1, cPNB vs. ssPNB = 21.1*% Absolute risk reduction, NRS ≥ 5 w/ movement on

POD 1, cPNB vs. ssPNB = 14.9*% Absolute risk reduction, NRS > 3 w/ movement on POD 2, cPNB vs. ssPNB = 21.2*% Absolute risk reduction, NRS ≥ 5 w/ movement on POD 2, cPNB vs. ssPNB = 15.4*

Quality Score(13 max.)

12 -1: technique (catheter placed after block administration).

Notes 2 lost to follow-up, 5 failed routine screening, 2 cancelled by anesthesiologist, 1 patient refusal after signup, 26 had change of surgical procedure, 1 failed to follow self-care instructions. Prospective trial performed in 2006 with subsequent retrospective analysis of outcomes twice in 2007 and once in 2009. Standardized multimodal analgesia included COX inhibitors, ketamine, ketorolac, meperidine, and intraarticular neostigmine. Patients in both groups were instructed to take oxycodone (10mg sustained release twice daily) even if NRS pain score was 0.

Capdevila 2006 Results ( c+bPNB/cPNB/ssPNB ) Methods Prospective, randomized comparative trial. Neither

patient nor anesthesiologist blinded, though assessor was blinded.Randomization performed with a computer-generated table after successful block confirmed.

Participants 85 adult patients, ASA I-III, approached for inclusion, two of whom had catheter malfunctions and were excluded prior to randomization. For our statistical analysis the basal group and the basal + bolus group are combined.

N (c+bPNB) = 30 N (cPNB) = 30N (ssPNB) = 23

Block Nerve stimulator guided interscalene for acromioplasty or popliteal block for hallux valgus. Blocks were performed through catheter in both groups. 0.5% ropivacaine 30ml followed by infusion of 0.2% ropivacaine 7ml/hr or 5ml/hr with ≤10ml/hr PCA bolus for 72 hours. After randomization the SS group had catheter removed in PACU and morphine PCA started.

Outcomes VAS pain scores (0-100) recorded at 1, 4, and 12 hours after arrival in PACU and every morning during physical therapy. Physician and patient satisfaction, morphine consumption, side effects, and time until able to ambulate for 10 minutes were monitored.

Study terminated early (after 23rd SS patient) when preliminary data showed significant increase in functional exercise capacity and reduction in VAS scores in the continuous perineural infusion groups.

Continuous + bolus/ Continuous / SSVAS w/ movement 10 min after PACU arrival†: 0/0/0VAS w/ movement 1 hour after PACU arrival†: 0/0/0VAS w/ movement 4 hr after PACU arrival†: 0/0/1*VAS w/ movement 12 hr after PACU arrival†: 0/0/2.1*VAS w/ movement POD 1†: 1/0/2.1*VAS w/ movement POD 2†: 0/1/2.1*VAS w/ movement POD 3†: 0/0/1.2*Hours until able to walk for 10 min†: 12.5/20.5/40.5Mg ketoprofen consumed in 72 hr•: 100/200/500*% w/ free activity on day 1: 37/43/13*% w/ free activity on day 2: 63/43/34*% w/ free activity on day 3: 100/70/35*% w/ assistance needed for activity day 1: 40/47/50% w/ assistance needed for activity day 2: 31/50/66*% w/ assistance needed for activity day 3: 0/30/65*% with no activity on day 1: 23/10/37*% with no activity on day 2: 6/7/0

% with no activity on day 3: 0/0/0% with activity limited due to fatigue: 16/33/52*% w/ activity limited by postoperative pain:

10/23/47*% with activity limited by paresthesia: 23/40/0*% w/ activity limited by nausea/vomiting: 7/10/33*% with activity limited by numbness: 16/23/0**% with activity limited by dizziness: 10/10/33*% with activity limited by fear of falling: 33/50/33*% with activity limited due to other: 10/10/13% Incidence of nausea/vomiting: 10/13/39% Incidence of dizziness: 6/10/39% Incidence of sleep disturbances: 3/10/22% Incidence of pruritis: 0/7/13% Incidence of local vein inflammation: 0/0/17% Incidence of slight paresthesia: 17/33/9% Incidence of numbness: 3/6/0% Incidence of mechanical problem with IV or PNB

catheter: 17/13/39% Patients very satisfied: 63/57/22*% Patients satisfied: 17/23/24% Patients mildly satisfied: 13/17/35*% Patients not satisfied: 7/3/9% Physicians very satisfied: 70/63/35*% Physicians satisfied: 17/17/26% Physicians mildly satisfied: 0/17/26*% Physicians not satisfied: 13/3/13

Quality Score(13 max.)

9 -1: Allocation concealment not maintained.-1: Technique (no true SS group).-2: Blinding (neither patient nor anesthesiologist blinded though assessor was blinded).

Notes Six patients in PCA group, 2 patients in continuous infusion group, and 1 patient in basal+ bolus group had episodes of breakthrough pain and were admitted overnight. One patient in SS + PCA group was re-admitted for respiratory depression after PCA pump malfunctioned and delivered 50mg IV morphine in 12 hours.

Kean 2006 Results ( cPNB/ssPNB ) Methods Prospective, randomized comparative trial.

Anesthesiologist not blinded. Patient and assessor were blinded. Randomization by anesthesiologist writing “continuous infusion” or “single shot” on papers in unmarked envelopes which were mixed and numbered 1-16.

Participants 16 adult patients, ASA I-III, undergoing open shoulder surgery.

N (cPNB) = 8N (ssPNB) = 8

Block Preoperative interscalene block with 0.5% levobupivacaine 30ml. For continuous group catheter was then placed and infusion of 0.25% levobupivacaine at 5ml/hr for 24 hours. Single injection group received sham catheter attached to the skin with the tip of the catheter concealed by dressing and pump attached but clamped. Surgery performed under general anesthesia.

Outcomes VAS at 6,12, and 24 hours after block (scale 0-100); VAS in recovery room (scale 0-100) •: 5/10

time until first additional analgesic request; cumulative IV morphine PCA consumption; patient satisfaction; and nausea/vomiting were recorded.

VAS 6 hr postoperatively (scale 0-100) •: 1.25/9VAS 12 hr postoperatively (scale 0-100) •: 0.13/26.88*VAS 24 hr postoperatively (scale 0-100) •: 16.88/41.25Mean incidence of nausea: 0.88/0.25*Mean satisfaction (scale 0-100): 87/78*Mg IV morphine consumed at 6 hours•: 0/0.5Mg IV morphine consumed at 12 hours•: 0.13/3.38Mg IV morphine consumed at 24 hours•: 3.38/27.63*Time to first morphine requirement•: 20.03/13.39*

Quality Score(13 max.)

8 -2: randomization (quasi-randomization technique).-1: technique (Single injection technique followed by catheter placement).-1: blinding (anesthesiologist not blinded, though assessor and patients were blinded).-1: intent-to-treat (accidental catheter dislodgement not included in analysis).

Notes When unintentional catheter dislodgement occurred (n=1) a new patient was added to the study.

Salinas 2006 Results ( cPNB/ssPNB ) Methods Prospective, randomized comparative trial. Neither

patient nor anesthesiologist blinded, though assessor was blinded. Randomized by computer-generated random numbers.

Participants 36 ASA I-III patients scheduled for primary total knee arthroplasty under spinal anesthesia.

N (cPNB) = 18N (ssPNB) = 18

Block Femoral nerve block for TKA. ssPNB with 0.375% ropivacaine 30ml through needle. cPNB with 0.375% ropivacaine 30ml through catheter followed by 0.2% ropivacaine 10ml/hr for 36 hr.

Initial femoral nerve block was successful in all 36 patients.

Outcomes Postoperative pain at rest and with physical therapy (PT) assessed 4, 8, and 12 hours after block and POD 1, 2, 3; morphine and oxycodone consumption; antiemetic requests; hospital length of stay; knee flexion at 6 and 12 weeks postoperatively.

Resting VAS 4 hours after block•: 2.1/2.6Resting VAS 8 hours after block•: 2.7/2.8Resting VAS 12 hours after block•: 2.4/2.4Resting VAS POD 1 (AM)•: 1.7/3.3*Resting VAS POD 1 (PM)•: 1.7/3.8*Resting VAS POD 2 (AM)•: 0.9/3.2*Resting VAS POD 2 (PM)•: 1.3/3.3*Resting VAS POD 3 (AM)•: 1.7/2.6Peak VAS during PT POD 1•: 4.7/6.3*Peak VAS during PT POD 2•: 3.9/6.1*Mg morphine consumed POD 0•: 16/25*Mg oxycodone consumed POD 1•: 15/40*Mg oxycodone consumed POD 2•: 20/43*Mg oxycodone consumed POD 3•: 10/26*Cumulative mg oxycodone consumed•: 45/109*Hospital length of stay (days) •: 3.8/3.9Degrees of knee flexion at 6 wks•: 108/10297Degrees of knee flexion at 12 wks•: 117/113

Quality Score(13 max.)

10 -1: blinding (anesthesiologist, patient, assessors not blinded).

Notes Multimodal analgesia included scheduled ibuprofen.

Cuignet 2005 Results ( Continuous/SS ) Methods Prospective, randomized, double-blind comparative

trial. Anesthesiologist, patient, and observer blinded. Randomization of patients not described. Preparation of randomized study solution not described.

Participants 81 burn patients undergoing unilateral skin graft of the thigh.

N (Ropivacaine SS + Infusion): 27N (Ropivacaine SS + saline infusion): 27N (Saline SS + infusion): 27

Block Fascia iliaca compartment block under GA or spinal prior to surgery followed by continuous infusion of 0.2% ropivacaine or NS.1. 0.2% ropivacaine 40ml bolus followed by 0.2% ropivacaine 10ml/hr infusion2. 0.2% ropivacaine 40ml bolus followed by 0.9% NS 10ml/hr infusion.3. 0.9% NS 40ml bolus followed by continuous infusion of NS.

Outcomes VAS at 6, 24, 48, and 72 hr; cumulative morphine consumption; Bromage score (1 = no motor block, 2 = inability to lift the thigh against resistance, 3 = inability to lift thigh against gravity, 4 = inability to move the thigh); patient satisfaction; and side effects were recorded.

Mg IV morphine consumption in 72 hr•: 5/6# with nausea/vomiting: 2/1# with constipation: 3/2# with pruritis: 17/16# with urinary retention: 0/1# with local anesthetic toxicity: 0/0Bromage score•: 2/1*Mean dynamic VAS score 6 hr postoperatively†: 1/2Mean dynamic VAS score 24 hr postoperatively†: 1/3Mean dynamic VAS score 48 hr postoperatively†: 2/3Mean dynamic VAS score 72 hr postoperatively†: 2/3Mean dynamic VAS score w/ 1st dressing change†: 3/6*Mean static VAS score 6 hr postoperatively†: 2/2Mean static VAS score 24 hr postoperatively†: 0/2Mean static VAS score 48 hr postoperatively†: 0.5/1.25Mean static VAS score 72 hr postoperatively†: 2/1.75% patients w/ satisfaction rated “very good”: 33/48% patients w/ satisfaction rated “poor”: 15/7% patients w/ satisfaction rated “very poor”: 11/0

Quality Score(13 max.)

9 -3: randomization (technique not described).-1 technique (block done through needle before catheter placement).

Notes Authors state that lower satisfaction in continuous nerve block group was related to motor block causing anxiety.

Watson 2005 Results ( cPNB/ssPNB ) Methods Prospective, randomized comparative trial.

Anesthesiologist, patient, and observer blinded.Randomized, by computer-generated random numbers, and delivered in sealed envelopes.

Participants 32 adult patients, ASA I-III, with osteoarthritis undergoing total knee arthroplasty.

N (cPNB) = 16N (ssPNB) = 16

Block Lumbar plexus block with 0.5% levobupivacaine 25ml, catheter thread in both groups. cPNB group received 0.1% levobupivacaine at 10ml/hr while SS group received NS 10ml/hr for 48 hours.Single injection sciatic block performed for all patients. Surgery under spinal and sedation.

Outcomes Morphine consumption, VAS pain score at rest and with movement, day of first ambulation, time to meet discharge criteria, and antiemetic requirement were recorded. Patients assessed at 4, 8, 12, 24, 36, and 72 hours after start of surgery.

Cumulative mg IV morphine†: 19/32*# doses of antiemetic†: 0.5/0Total nausea score†: 0.5/1Area under static pain curve†: 55/161Area under dynamic pain curve†: 220/318

Day of first ambulation†: 2/2*Days until discharge criteria met†: 6/6Day of actual discharge†: 6/7Highest VAS first night†: 3/5.5VAS at rest 4 hr after surgery start†: 0/0VAS at rest 8 hr after surgery start†: 0/0VAS at rest 12 hr after surgery start†: 1/2VAS at rest 24 hr after surgery start†: 2.5/4VAS at rest 36 hr after surgery start†: 0/2VAS at rest 48 hr after surgery start†: 1/0VAS at rest 72 hr after surgery start†: 0/2VAS w/ movement 4 hr after surgery start†: 0/0VAS w/ movement 8 hr after surgery start†: 0/0VAS w/ movement 12 hr after surgery start†: 2/1VAS w/ movement 24 hr after surgery start†: 5.75/8VAS w/ movement 36 hr after surgery start†: 4.5/5.5VAS w/ movement 48 hr after surgery start†: 4.5/4.5VAS w/ movement 72 hr after surgery start†: 3/4.4

Quality Score(13 max.)

12 -1: technique (block done through needle before catheter placement).

Notes Patients excluded after consent but prior to randomization:1- unable to locate lumbar plexus.1- partial intravascular injection; procedure abandoned.1- catheter dislodged prior to surgery

All patients reported being satisfied with their anesthetic.

Zaric 2004 Results ( cPNB/ssPNB ) Methods Randomization performed by central pharmacy.

Study solution prepared by pharmacy and blinding of anesthesiologist, patient, and assessors was maintained.

Participants 63 adult patients, ASA I-II, undergoing hallux valgus surgery.

N (cPNB) = 30N (ssPNB) = 30

Block Surgery under spinal anesthesia with sedation. Followed by sciatic and saphenous blocks in PACU. Sciatic block performed with 0.5% ropivacaine 30ml, then catheter thread and infusion at 5ml/hr of either 0.2% ropivacaine or NS. Saphenous block with 0.75% Ropivacaine 10ml.

Outcomes VAS pain score, sleep, paresthesia, motor block, adverse effects, satisfaction with comfort and convenience of technique on 5 point scale (very satisfied, satisfied, neutral, not satisfied, very unsatisfied).

Numeric VAS extrapolated from Table (raw data not available).

VAS at discharge•: 0.2/0.7VAS 8 p.m. POD 0•: 0.3/1.6Worst VAS POD 0•: 3.3/6.4*VAS 9 a.m. POD 1•: 1.8/4.2*Worst VAS POD 1•: 4.9/7.6*VAS 8 p.m. POD 1•: 3.6/5.2*VAS 9 a.m. POD 2•: 2.1/3.4*Worst VAS POD 2•: 4.6/5.0VAS 9 a.m. POD 3•: 2.5/2.0# tablets ketomebidone consumed in 3 days†: 2/3# with PONV POD 0†: 7/6# with PONV POD 1†: 11/8# with PONV POD 2†: 9/5# patients very satisfied: 18/13# patients satisfied: 11/14

# patients neutral: 1/2# patients not satisfied: 0/1# patients very unsatisfied: 0/0# Unable to sleep on 1st nigh at home: 6/15*Time pain-free postsurgically•: 23hr 44min/ 18hr16min*# patients requiring admission: 3/1Min. from end of surgery to discharge•: 203.9/209.2

Quality Score(13 max.)

8 -3: randomization (methods not described).-1: technique (block done through needle before catheter placement).-1: intent-to-treat (dropouts excluded).

Notes 3 patients excluded from analysis due to breach of protocol.

Ilfeld 2003 Results ( cPNB/ssPNB ) Methods Prospective, randomized, double-blind comparative

trial. Anesthesiologist, patient, and observer blinded.Randomized, by computer-generated random numbers.

Participants 25 adult patients, ASA status unspecified, undergoing moderately painful shoulder surgery. Two with failed block and 2 with catheters that could not be advanced past the needle tip. One was admitted for social reasons and was excluded. The remaining 20 subjects were randomized to receive either ropivacaine (n = 10) or saline (n = 10) infusion.

N (cPNB) = 10N (ssPNB) = 10

Block Interscalene catheter with initial 1.5% mepivacaine 40ml block followed by continuous infusion of 0.2% ropivacaine or NS at 8ml/hr for 48 hours.

Outcomes Average VAS at rest and worst VAS overall (scale 0-10) on POD 0, 1, 2, and 3; opioid use; satisfaction (0 = very dissatisfied,10 = very satisfied); nausea (1 = moderate 3 = severe); sedation (1 = drowsy, (2) dozing intermittently, (3) mostly asleep, (4) awake only when aroused); and pruritis (1 = only under surgical dressings, (2) on other parts of body [minimal (2), moderate (3), or severe (4)]).

Average VAS at rest POD 0†: 0/6*Average VAS at rest POD 1†: 0/4.75*Average VAS at rest POD 2†: 1.5/4*Average VAS at rest POD 3†: 3.25/3.0Worst VAS POD 0†: 1.5/8.0*Worst VAS POD 1†: 3.25/8.0*Worst VAS POD 2†: 3.5/7.0*Worst VAS POD 3†: 7.5/7.0Tablets oxycodone used POD 0†: 0/4*Tablets oxycodone used POD 1†: 0.5/8*Tablets oxycodone used POD 2†: 0/6*Tablets oxycodone used POD 3†: 5.5/3.5% cPNB group who used ≤1 opioid tab during infusion: 60% of ssPNB group receiving ≥ 4 opioid tabs by evening of POD 0: 100*Average patient satisfaction: 8.8/6.5*% patients who would repeat this technique: 90/50Nausea score POD 1†: 0/1*Nausea score POD 2†: 0/1*Nausea score POD 3†: 0/0Sedation score POD 1†: 0.5/2*Sedation score POD 2†: 0/1.5*Sedation score POD 3†: 1.5/1Pruritis score POD 1†: 0/1*Pruritis score POD 2†: 1/1

Pruritis score POD 3†: 1/0.5% with insomnia POD 1†: 30/70% with insomnia POD 2†: 30/70% with insomnia POD 3†: 60/50# awakenings 1st postoperative night†: 0/2*# awakenings 2nd postoperative night†: 0/1# awakenings 3rd postoperative night†: 0.5/1

Quality Score(13 max.)

12 -1: technique (block done through needle before catheter placement).

Notes Multimodal analgesia included ketorolac.

White 2003 Results ( cPNB/ssPNB ) Methods Prospective, randomized, double-blind, comparative

trial. Randomization by computer-generated table.Study solution prepared by pharmacy and blinding of anesthesiologist, patient, and assessors was maintained.

Participants 24 enrolled. Four dropouts. Adults, ASA I-III, undergoing foot or ankle surgery (including bunionectomy, clawtoe correction, hammertoe correction, bone fusions or internal fixation).

N (cPNB) = 10N (ssPNB) = 10

Block 0.25% bupivacaine 30ml injected through needle, catheter then thread. Infusion of 0.25% bupivacaine vs. NS at 5 ml/hr for 48 hours.

Outcomes VRS at 1, 2, 4, 8, 24, 48, and 72 h after surgery (scale 0-10); opioid use, numbness, time to discharge, and patient satisfaction on 0-100 scale (1 = highly dissatisfied, 100 = highly satisfied).

Numeric VRS scores at 1hr, 2hr, 4hr, 8hr, 24hr, 48hr, and 72hr are extrapolated from figure provided in article.

VRS POD 0†: 2.5/7.5*VRS POD 1†: 2/5*VRS POD 2†: 2/4VRS POD 3†: 2/5VRS POD 7†: 2/2VRS 1 hr postoperatively•: 2.65/6.8VRS 2 hr postoperatively•: 2.1/7.1VRS 4 hr postoperatively•: 1.7/5.45VRS 8 hr postoperatively•: 1.25/5.9VRS 24 hr postoperatively•: 1.5/4.75VRS 48 hr postoperatively•: 1.5/3.7VRS 72 hr postoperatively•: 1.8/3.1Maximum VAS in hospital†: 4/8*Maximum VAS after discharge†: 2.5/7.5*Cumulative mg morphine consumed•: 10.3/34.7*# requiring rescue analgesic in PACU: 7/10% using rescue antiemetic drug: 10/40% with leg weakness or numbness: 0/0% with “tingling sensation” in foot: 80/10**% completely satisfied w/ pain management: 90/10*Satisfaction w/ anesthetic management•: 96/96Satisfaction w/ pain control•: 98/77*Satisfaction w/ quality of recovery•: 98/63*PACU stay (min) •: 69/98# discharged same-day: 4/0# admitted for 23 hours: 5/6# admitted as inpatient: 1/4# admitted for pain control: 4/10# admitted for social reason: 2/0Average hospital length of stay•: 0.7/1.4*Mcg fentanyl given for block placement•: 117/100Mcg alfentanil given intraoperatively•: 9/21

Quality Score(13 max.)

11 -1: technique (block done through needle before catheter placement).

-1: intent-to-treat (4 patients eliminated from analysis due to catheter dislodgement prior to discharge from hospital).

Notes

Ilfeld 2002 Results ( cPNB/ssPNB ) Methods Prospective, randomized, double-blind comparative

trial. Anesthesiologist, patient, and observer blinded. Randomized, by computer-generated random numbers.

Participants 35 patients, ASA I-II, undergoing upper extremity orthopedic surgery. 5 patients withdrawn from the study due to intravascular catheter placement (discovered at time of insertion).

N (cPNB) = 15N (ssPNB) = 15

Block Surgical infraclavicular block through needle with 1.5% mepivacaine 50ml followed by threading of catheter and infusion of 0.2% ropivacaine or NS at 8 ml/hr with ≤6ml/hr PCA bolus for 48 hours.

Outcomes Pain scores at rest and with movement (scale 0-10), tablets of PO medication used (acetaminophen 500mg/oxycodone 5mg) and side effects, sleep quality, patient satisfaction ((0 = very dissatisfied, 10 = very satisfied), catheter and local anesthetic complications.

Average VAS at rest POD 0•: 0.5/3.9*Average VAS at rest POD 1•: 1.0/4.3*Average VAS at rest POD 2•: 0.6/4.0*Average VAS at rest POD 3•: 1.7/2.5Worst VAS at rest POD 0•: 0.7/5.0*Worst VAS at rest POD 1•: 2.9/7.1*Worst VAS at rest POD 2•: 2.0/6.0*Worst VAS at rest POD 3•: 3.5/3.9Average pain with movement POD 0•: 0.6/4.7*Average pain with movement POD 1•: 2.5/6.1*Average pain with movement POD 2•: 1.5/5.1*Average pain with movement POD 3•: 3.5/3.9Worst pain with movement POD 0•: 0.9/5.5*Worst pain with movement POD 1•: 4.5/7.9*Worst pain with movement POD 2•: 3.7/6.8*Worst pain with movement POD 3•: 5.3/5.8Narcotic tabs used POD 0•: 0.3/2.5*Narcotic tabs used POD 1•: 1.7/5.5*Narcotic tabs used POD 2•: 1.4/5.3*Narcotic tabs used POD 3•: 2.8/4.6*# with nausea POD 1: 2/8*# with nausea POD 2: 3/6# with nausea POD 3: 2/3# with sedation POD 1: 5/11*# with sedation POD 2: 6/10# with sedation POD 3: 8/6# with pruritis POD 1: 2/4# with pruritis POD 2: 3/5# with pruritis POD 3: 3/6# difficulty sleeping due to pain POD 1: 0/9*# difficulty sleeping due to pain POD 2: 1/6# difficulty sleeping due to pain POD 3: 4/4# awakenings due to pain POD 1•: 0.1/2*# awakenings due to pain POD 2•: 0.1/1.15*# awakenings due to pain POD 3•: 0.7/0.8

Quality Score(13 max.)

12 -1: technique (catheter placed after SS block).

Notes There were no apparent complications or catheter dislocations during the study period.

Ilfeld 2002 Results ( cPNB/ssPNB )

Methods Prospective, randomized, double-blind, comparative trial. Randomization by computer generated table.

Participants 30 patients, ASA I-II, undergoing surgery distal to the knee out of distribution of saphenous nerve.

N (cPNB) = 15N (ssPNB) = 15

Block Popliteal sciatic block performed through needle with 1.5% mepivacaine 50ml, then catheter advanced. Patients received 0.2% ropivacaine or NS at 8ml/hr with up to 6ml/hr PCA bolus for 48 hours.

Outcomes Pain scores at rest and with movement, narcotic use and side effects, sleep quality, patient satisfaction ((0 = very dissatisfied, 10 = very satisfied), catheter- or local anesthetic-related complications.

Average VAS at rest POD 0†: 0/3*Average VAS at rest POD 1†: 0/4*Average VAS at rest POD 2†: 0/3*Average VAS at rest POD 3†: 1.5/2Worst VAS POD 0†: 0/7*Worst VAS POD 1†: 0/7*Worst VAS POD 2†: 1/6*Worst VAS POD 3†: 4.5/4Tablets oxycodone used POD 0†: 0/3*Tablets oxycodone used POD 1†: 0/8*Tablets oxycodone used POD 2†: 0/5*Tablets oxycodone used POD 3†: 4/4% using no opioids during perineural infusion: 80/7*Average satisfaction with analgesia: 9.7/5.5*% who would repeat analgesic technique: 100/46*Nausea score POD 1†: 0/1*Nausea score POD 2†: 0/0*Nausea score POD 3†: 0/0Sedation score POD 1†: 0/2*Sedation score POD 2†: 0/1*Sedation score POD 3†: 0/1.75Pruritis score POD 1†: 0/2*Pruritis score POD 2†: 0/1*Pruritis score POD 3†: 0/1% with insomnia POD 1†: 8/68*% with insomnia POD 2†: 8/60*% with insomnia POD 3†: 48/40*# awakenings postoperative night 0•: 0.2/2.3*# awakenings postoperative night 1•: 0.1/1.6*# awakenings postoperative night 2•: 1.2/0.7

Quality Score(13 max.)

11 -1: anesthetic care may not have been identical (saphenous block).-1: technique (catheter placed after block administration).

Notes 1 unintentional catheter dislodgement on POD 1 in each group. No adverse effects in either group.

Borgeat 2000 Results ( cPNB/ssPNB ) Methods Prospective, randomized, unblinded, comparative

trial. Randomization by computerized randomization list.

Participants 35 patients, ASA I-II, undergoing shoulder surgery. N (cPNB) = 18N (ssPNB) = 15

Block Interscalene block with 0.75% ropivacaine 30ml through needle in SS group, through catheter in cPNB group. Continuous group received 0.2% ropivacaine 5ml/hr infusion plus up to 9-12ml/hr bolus (depending on weight). Continuous nicomorphine plus IV PCA nicomorphine provided to SS group. Standardized general anesthetic for

surgery.Outcomes VAS assessed at rest 6, 12, 24, 36, and 48 hours

after the interscalene block.Patient satisfaction assessed 54 hours after the interscalene block using a visual analog score (0 = not satisfied, 10 = entirely satisfied).Respiratory parameters monitored: diaphragmatic excursion as measured by ultrasound, vital capacity (Liters), FEV1 (Liters), peak expiratory flow rate (L/min), and pulse oximetry.

VAS at rest 6 hours after block†: 0/0VAS at rest 12 hours after block†: 6/30*VAS at rest 24 hours after block†: 4.5/20*VAS at rest 36 hours after block†: 0/14.5VAS at rest 48 hours after block†: 0/0# nausea/vomiting: 1/9*# pruritis: 1/3Patient satisfaction•: 9.7/7.5*cm tidal excursion operative side diaphragm 20 min after block•: 0.9/0.4cm forced excursion operative side diaphragm 20 min after block•: 1.9/0.6cm tidal excursion operative side diaphragm 24 hr after block•: 1.1/1.4cm forced excursion operative side diaphragm 24 hr after block•: 2.6/2.8cm tidal excursion operative side diaphragm 48 hr after block•: 1.2/1.8cm forced excursion operative side diaphragm 48 hr after block•: 3/3.9cm tidal excursion non-operative side diaphragm 20 min after block•: 2.2/2cm forced excursion non-operative side diaphragm 20 min after block•: 4.8/4.5cm tidal excursion non-operative side diaphragm 24 hr after block•: 2.4/1.7cm forced excursion non-operative side diaphragm 24 hr after block•: 4.8/3.2*cm tidal excursion non-operative side diaphragm 48 hr after block•: 2.5/1.7cm forced excursion non-operative side diaphragm 48 hr after block•: 4.5/2.7*Vital capacity preoperatively•: 3.7/3.8Vital capacity 20 min after block•: 2.4/2.6Vital capacity 24 hr after block•: 2.6/3.1Vital capacity 48 hr after block•: 2.9/3.3FEV1 preoperatively•: 2.9/3.0FEV1 20 min after block•: 1.8/2.1FEV1 24 hr after block•: 2.0/2.4FEV1 48 hr after block•: 2.3/2.6Peak expiratory flow rate preoperatively•: 7.0/6.7Peak expiratory flow rate 20 min after block•: 4.6/5.1Peak expiratory flow rate 24 hr after block•: 5.1/5.7Peak expiratory flow rate 48 hr after block•: 5.6/6.0

Quality Score(13 max.)

9 -2: blinding (anesthesiologists and patients not blinded, though assessor was blinded).-1: allocation (group allocation not well concealed).-1: intent-to-treat (dropouts were excluded).

Notes Two patients were excluded from the study in the IV nicomorphine group due to intractable vomiting that necessitated change in pain treatment.

Klein 2000 Results ( cPNB/ssPNB ) Methods Prospective, randomized, blinded, comparative trial.

Randomization not described.Participants ASA I-III, undergoing open rotator cuff repair. N (cPNB) = 22

N (ssPNB) = 18

Block Initial surgical interscalene with 0.5% ropivacaine 30ml, then catheter placed in continuous group. Ropivacaine 0.2% or NS at 10ml/hr for 24 hours.

Outcomes VAS pain scores at 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, and 24 hours postoperatively; opioid requirement; patient satisfaction (0 = dissatisfied, 10 = very satisfied).

VAS 2 hours postoperatively•: 0/0VAS 4 hours postoperatively•: 0/0.15VAS 6 hours postoperatively•: 0.65/1.15VAS 8 hours postoperatively•: 0.5/1.45VAS 10 hours postoperatively•: 1.3/1.2VAS 12 hours postoperatively•: 1/3.4*VAS 14 hours postoperatively•: 1.2/3.2*VAS 16 hours postoperatively•: 0.55/3.15*VAS 18 hours postoperatively•: 0.85/2.75*VAS 20 hours postoperatively•: 1.3/2.5*VAS 22 hours postoperatively•: 0.8/3.2*VAS 24 hours postoperatively•: 1.6/2.85*Total mg postoperative morphine used•: 18/36*% requiring no morphine in 1st 24 hr postoperatively: 54/5Serum ropivacaine level (mcg/ml) •: 1.04/0.34**Satisfaction with anesthesia•: 10/10Satisfaction with analgesia•: 10/9

Quality Score(13 max.)

8 -3: randomization (not described).-1: technique (catheter placed after SS block).-1: intent-to-treat analysis (patient with catheter removal at 6 hours due to neck pain was not described).

Notes

Borgeat 1998 Results ( cPNB/ssPNB ) Methods Prospective, randomized, comparative trial.

Randomization according to a computerized table.Participants 65 patients, ASA I-II, undergoing elective shoulder

arthroplasty or rotator cuff repair. N (cPNB) = 30N (ssPNB) = 30

Block Interscalene block with 0.75 % ropivacaine 30ml which was given through catheter for continuous infusion group. A standardized general anesthetic was administered. The cPNB group received continuous 0.2% ropivacaine at 5ml/hr which ssPNB group received continuous infusion of nicomorphine 0.5mg/hr with PCA bolus of 2-3mg q 20 minutes.

Outcomes VAS pain score at 0, 6, 12, 18, 24, 30, 36, 42, and 48 hours after interscalene block (scale 0-100), incidence of nausea, vomiting, pruritis, or other side effects; time of first perineural interscalene or IV PCA bolus, motor block (defined by difficulty flexing or extending any of the fingers 12 hours after block); and patient satisfaction 6 hours after end of the study (0 = not satisfied, 10 = entirely satisfied).

VAS 0 hr after block•: 0/0VAS 6 hours after block•: 0/0VAS 12 hours after block•: 4/24*VAS 18 hours after block•: 14/38*VAS 24 hours after block•: 13/47*VAS 30 hours after block•: 10/39*VAS 36 hours after block•: 9/30*VAS 42 hours after block•: 7/27VAS 48 hours after block•: 4/24*# with nausea: 3/14*# with vomiting: 2/8# with pruritis: 0/8*# with motor block: 6/4Time of first interscalene or IV PCA bolus (min) •: 930/786Paracetamol supplement (g) •: 2.1/3.5

Patient satisfaction•: 9.6/7.5*

Quality Score(13 max.)

9 -2: blinding (anesthesiologists and patients unblinded, assessor blinded).-1: allocation (group allocation not well concealed).-1: intent-to-treat (XXX)

Notes 5 patients excluded: 3 in cPNB group and 2 in ssPNB group. In 2 patients in group cPNB the interscalene catheter was prematurely dislodged, and in one patient the IS catheter could not be placed. In ssPNB one patient was withdrawn because of intractable vomiting due to nicomorphine and another asked to be withdrawn due to dizziness every time he pushed his button.

Borgeat 1997 Results ( cPNB/ssPNB ) Methods Prospective, randomized, comparative trial.

Randomization by computerized randomization list.Participants 43 patients, ASA I-II, undergoing elective shoulder

arthroplasty or rotator cuff repair. 3 dropouts.N (cPNB) = 20N (ssPNB) = 20

Block Interscalene block performed prior to surgery. ssPNB block performed through needle. cPNB block performed through catheter. Initial block with 0.4% bupivacaine 30ml. Standardized general anesthetic. For 48 hours after surgery cPNB group received 0.15% bupivacaine at 5ml/hr while ssPNB group received continuous IV nicomorphine at 0.5mg/hr plus bolus of 2-3mg q 20min.

Outcomes VAS pain score at 0, 6, 12, 18, 24, 30, 36, 42, and 48 hours after perineural or PCA infusion started in recovery room (scale 0-100), incidence of nausea, vomiting, pruritis, or other side effects; time of first perineural interscalene or IV PCA bolus, motor block (defined by difficulty flexing or extending any of the fingers 12 hours after block); and patient satisfaction 6 hours after end of the study (0 = not satisfied, 10 = entirely satisfied).

VAS 0 hr•: 0/1VAS 6 hours•: 0/10VAS 12 hours•: 2.5/24*VAS 18 hours•: 12.5/31*VAS 24 hours•: 19/32VAS 30 hours•: 17.5/30VAS 36 hours•: 15/20VAS 42 hours•: 14/13VAS 48 hours•: 11/16# with nausea: 3/6# with vomiting: 0/5*# with pruritis: 0/5*# with motor block: 7/4Time of first interscalene or IV PCA bolus (min) •: 892/832Paracetamol supplement (g) •: 1.2/1.8Patient satisfaction•: 9.8/7.6*

Quality Score(13 max.)

9 -2: blinding (anesthesiologists and patients unblinded. Assessor blinded).-1: group allocation (not concealed).-1: intent-to-treat (dropouts from both groups were excluded).

Notes 3 patients were excluded from study after randomization: 2 in cPNB group- one unintentional catheter dislodgement and one failed catheter placement. 1 in ssPNB group withdrawn due to vomiting related to nicomorphine.

Hirst 1996 Results ( cPNB/ssPNB )

Methods Prospective, comparative trial.

Participants Thirty three patients, ASA XXX, divided into 3 groups N (cPNB) = 11N (ssPNB) = 11

Block Group 1- SS femoral 3-in-1 with 0.5% bupivacaine with epinephrine 20ml injected through needle.Group 2- Continuous femoral 3-in-1 with 0.5% bupivacaine 20ml injected through catheter.Group 3- mock nerve block followed by attachment of sham catheter flowing into reservoir (group 3 disregarded for our analysis).Standardized general anesthetic after block.

Outcomes VAS at 2, 6, 12, 18, 24, and 48 hours after surgery (scale 0-100); pain at rest and with motion (30° passive flexion); side effects, overall patient satisfaction; PCA morphine requirement, and XXX.

VAS w/ movement 0 hr •: 52/48*VAS w/ movement 12 hours•: 62/58VAS w/ movement 24 hours•: 60/68VAS w/ movement 48 hours•: 58/54VAS w/ movement 72 hours•: 42/45VAS at rest 0 hr •: 31/38VAS at rest 12 hours•: 32/29VAS at rest 24 hours•: 18/24VAS at rest 48 hours•: 13/29VAS at rest 72 hours•: 21/17mg morphine PCA 0-24 hours•: 25/41mg morphine PCA 24-48 hours•: 18/24% with nausea 24 hours postoperatively: 36/45% with nausea 48 hours postoperatively: 9/9

Quality Score(13 max.)

7 -3: randomization (methods not described).-1: allocation (not well concealed).-2: blinding (anesthesiologists not blinded, patients were blinded, possible unblinding of assessors).

Notes Authors report no difference between overall satisfaction; 97% of all patients were either satisfied or very satisfied.

* = p < 0.05 favoring cPNB**= p < 0.05 favoring ssPNB† = median• = mean₊It is the opinion of the authors that catheters placed after a through-the-needle bolus of LA may not be ideal for use in a continuous block group as data are reported as means or medians for the group and secondary block failure rates are not reported.