An analysis of 1505 consecutive patients receiving continuous interscalene analgesia at home: a multicentre prospective safety study.

Continuous interscalene brachial plexus block has been shown to be the most effective analgesic technique following shoulder surgery; however, its use is uncommon due to logistical and safety concerns related to ambulatory administration. We prospectively studied 1505 consecutive patients undergoing shoulder surgery who received continuous interscalene analgesia at home. Catheter removal was by the patient between postoperative days two and five. There were no major complications although 27% of patients reported mild dyspnoea, 13% hoarseness and 7% dysphagia. Twelve percent sought medical advice and 2% reported technical issues with the pump or tubing. Complications and technical issues were associated with patient age; weight; use of ultrasound or concomitant nerve stimulation as the endpoint for final needle tip position; local anaesthetic placement via the catheter or needle; whether a catheter-related intervention for pain relief was required in the recovery area; and the type of ambulatory pump. We conclude that this study supports the safety of this underused analgesic technique.

Spinal anaesthesia with adjunctive intrathecal morphine versus continuous lumbar plexus blockade: a randomised comparison for analgesia after hip replacement.

Following elective total hip replacement, both continuous lumbar plexus blockade and spinal anaesthesia (with adjunctive intrathecal morphine) have shown early outcome benefits over opioid analgesia and single-injection nerve block. However, the two techniques have not been compared in a prospective randomised manner. Our study examined 50 patients undergoing elective hip joint replacement who were randomised to receive spinal anaesthesia (with adjunctive intrathecal morphine 0.1 mg) or patient-controlled continuous lumbar plexus blockade. All surgery was conducted under general anaesthesia. Measured outcomes included numerically rated postoperative pain, supplemental opioid consumption and indices of mobilisation together with complications. Results show that block placement time was marginally shorter for the spinal group (5 versus 7 minutes, P=0.01). The primary outcome, worst pain on movement/mobilisation during the first 24 hours, was not statistically significantly different between groups. Patients in the lumbar plexus group were given more intraoperative opioid and rescue morphine in the post-anaesthesia care unit (median = 4 versus 0 mg, P <0.001), with correspondingly higher pain scores (median 5/10 versus 0/10, P <0.001). Pain scores during the subsequent 24 hours were similar between groups, but more patients in the spinal group were given rescue morphine (5 versus 0, P=0.02). Physiotherapy mobilisation indices appeared similar between groups. More spinal group patients reported pruritus (12 versus 5, P=0.01), but antiemetic requirements, episodes of disorientation, arterial oxygen desaturation and falls were all similar between groups. Postoperative symptoms suggestive of neurological irritation or injury did not differ between groups. We found that following elective hip joint replacement, compared to continuous lumbar plexus blockade, spinal anaesthesia incorporating adjunctive intrathecal morphine did not result in a statistically significant difference in worst pain on movement/mobilisation during the first 24 hours, although it was associated with better analgesia in the post-anaesthesia care unit. Subsequently, however, these patients appeared to require more rescue morphine and more of them reported pruritus.

Randomised comparison of an end-hole, triple-hole and novel six-hole catheter for continuous interscalene analgesia.

Epidural analgesia studies and a recent continuous peripheral nerve block study suggest multi-hole perineural catheters perform better than end-hole catheters. Confounding catheter positioning issues limit interpretation of the latter study. One hundred and fifty-six patients receiving an anterolateral interscalene catheter for elective shoulder surgery were randomised to three groups: following out-of-plane ultrasound confirmation of the needle tip immediately lateral to the C5/6 roots, an end-hole (n=52), triple-hole (n=53) or six-hole (n=51) non-stimulating catheter was positioned 3 cm beyond the needle tip. Ropivacaine 0.375% 15 ml was administered preoperatively via the catheter before surgery under general anaesthesia. A ropivacaine 0.2% 2 ml/hour infusion with mandatory six-hourly, and on-demand hourly, 5 ml boluses was continued for >48 hours with tramadol available as rescue. Patients were questioned in the recovery room and at 24 hours for numerical rating pain score (0 to 10), ropivacaine bolus and tramadol consumption. The frequency of recovery room pain was similar between groups (P=0.75) and demonstrated strong evidence for equivalence at the 5% significance level. Neither time to first pain, "average" or "worst" pain during the first 24 hours, ropivacaine bolus or tramadol consumption significantly differed between groups. Catheter threading difficulty was more common for the square-tipped end-hole catheters (end-hole=19% versus triple-hole=6%, six-hole=0%, P >0.001). This study found no evidence to support catheter orifice configuration significantly affecting the quality of continuous peripheral nerve blockade. These findings are in contrast to epidural catheter studies, and suggest that anatomical factors have a significant bearing on whether multi-orifice catheters confer advantage over the single-orifice design.

Ultrasound-guided femoral catheter placement: a randomised comparison of the in-plane and out-of-plane techniques.

In-plane vs out-of-plane needle-probe alignment for perineural catheter placement remains controversial. Patients presenting for major knee surgery were randomly assigned to out-of-plane (n = 42) or in-plane (n = 39) needle-probe alignment for femoral nerve catheter placement, with both techniques using short-axis nerve imaging. Twenty millilitres of ropivacaine 0.5% was administered via the catheter followed by a ropivacaine elastomeric infusion incorporating on-demand boluses. All patients received pre-operative single-injection sciatic and obturator blocks and general anaesthesia. The primary outcome, numerically rated worst pain on movement (0-10) during the first 24 h, demonstrated equivalence within two points of the scale at a 5% significance level using two one-sided tests (corresponding 90% CI -1.2 to 0.6). There were no differences between groups for all secondary outcomes, including numerically rated worst rest pain, ropivacaine bolus and tramadol consumption. These results suggest that for ultrasound-guided femoral catheter placement using short-axis nerve imaging, operators should use the needle-probe alignment technique with which they are most familiar.

Does motor block related to long-acting brachial plexus block cause patient dissatisfaction after minor wrist and hand surgery? A randomized observer-blinded trial.

BACKGROUND: Patient dissatisfaction has been previously associated with motor block in shoulder surgery patients receiving brachial plexus block. For elective minor wrist and hand surgery, we tested whether a regional block accelerating the early return of upper extremity motor function would improve patient satisfaction compared with a long-acting proximal brachial plexus block. METHODS: A total of 177 patients having elective 'minor' wrist and hand surgery under awake regional block randomly received adrenalized infraclavicular lidocaine 2% 10 ml+ropivacaine 0.75% 20 ml ('long acting', n=90), or adrenalized infraclavicular lidocaine 1.5% 30 ml+long-acting distal median, radial, and ulnar nerve blocks selected according to the anticipated area of postoperative pain ('short acting', n=87). A blinded observer questioned patients on day 1 for numerically rated (0-10) subjective outcomes. RESULTS: With 95% power, there was no evidence for a 1-point satisfaction shift in the short acting group: satisfaction was similarly high for both groups [median (inter-quartile range)=10 (8-10) vs 10 (8-10), P=0.71], and also demonstrated strong evidence for equivalence [mean difference (95% confidence interval)=-0.18 (-0.70 to 0.35)]. There was no difference between the groups for weakness- or numbness-related dissatisfaction (low for both groups), or for numerically rated or time to first pain. Surgical anaesthesia success was similar between the groups (short acting, 97% vs 93%, P=0.50), although more patients in the short acting group had surgery initiated in ≤25 min (P=0.03). CONCLUSIONS: Patient satisfaction is not improved after elective minor wrist and hand surgery with a regional block accelerating the early return of motor function. For this surgery, motor block related to a long-acting brachial plexus block does not appear to cause patient dissatisfaction. Clinical Trial Registration number. ACTRN12610000749000, https://www.anzctr.org.au/registry/trial_review.aspx?ID=335931.

Concomitant infraclavicular plus distal median, radial, and ulnar nerve blockade accelerates upper extremity anaesthesia and improves block consistency compared with infraclavicular block alone.

BACKGROUND: This prospective, randomized, observer-blinded study tested the hypothesis that a combined ultrasound-guided block of the infraclavicular brachial plexus plus distal median, radial, and ulnar nerves would accelerate upper extremity anaesthesia compared with infraclavicular block alone. METHODS: Elective wrist and hand surgery patients were randomly assigned to receive 42 ml infraclavicular lidocaine 1.5% with epinephrine 1/200,000 ('infraclavicular only'; n=30) or 30 ml lidocaine 1.5% with epinephrine 1/200,000 followed by a distal median, radial, and ulnar nerve block using 12 ml 50:50 lidocaine 2%+ropivacaine 0.75% ('combined'; n=31). A blinded observer assessed pinprick sensory and motor block in the four distal nerve territories at 10 and 15 min (each nerve/parameter: no block, 3, to complete block, 0). RESULTS: Total aggregate block score (sensory+motor) was reduced in the combined group at 15 min [mean (95% confidence interval)=6.7 (5.3-8.1) vs. 9.9 (7.9-11.9), mean difference (95% confidence interval)=3.2 (0.81-5.6), P=0.01], and corresponded to an estimated onset effect time benefit of 6 min (∼40% treatment effect). The combined group also demonstrated reduced variance about the mean (sd=3.7 vs. 5.4, P=0.046). Mean (sd) total block score (sensory+motor) was significantly reduced at 15 min in the combined group for each individual nerve [median, radial, ulnar, respectively: 1.4 (1.1) vs. 2.4 (1.5), P=0.005; 1.2 (1.1) vs. 2.0 (1.5), P=0.03; 1.6 (1.3) vs. 2.5 (1.6), P=0.03]. CONCLUSIONS: At an approximately equivalent total local anaesthetic dose, a combined infraclavicular block plus distal median, radial, and ulnar nerve blockade accelerates anaesthesia onset time and improves block consistency compared with an infraclavicular block alone. CLINICAL TRIALS REGISTRY: ANZCTR: ACTRN12610000155099. https://www.anzctr.org.au/registry/trial_review.aspx?ID=335162.

Patient-initiated mandatory boluses for ambulatory continuous interscalene analgesia: an effective strategy for optimizing analgesia and minimizing side-effects.

BACKGROUND: This prospective, randomized study tested the hypothesis that a reduced dose continuous interscalene regimen incorporating a low background infusion with mandatory boluses would provide similar shoulder surgery analgesia compared with a dose regimen incorporating a conventional higher background infusion. METHODS: After rotator cuff surgery, patients received via an interscalene catheter, one of two elastomeric pumps, each having a 5 ml per 60 min bolus function and a 2 ml h⁻¹ (n=38) or 5 ml h⁻¹ (n=43) ropivacaine 2 mg ml⁻¹ infusion. Boluses commenced from the onset of pain and continued for >48 h as required (pro re nata, PRN) up to every hour for a numerical rating pain score (NRPS, 0-10) >2. Group 2 ml h⁻¹ received mandatory 6 hourly boluses irrespective of the NRPS. Rescue tramadol was available. Patients were questioned on postoperative days 1 and 2 for treatment effectiveness and side-effects. RESULTS: Postoperative pain was similar between the groups [Group 2 ml h⁻¹ day 2 median (IQR) (95% confidence interval of the mean) worst movement pain=4 (1-5) (2.8-4.7) vs 4 (2-5) (3.1-4.6), P=0.99], as were night awakenings and tramadol consumption. Numerically rated numbness and weakness were similar between the groups; however, nine patients (21%) in the 5 ml h⁻¹ group vs one (3%) in the 2 ml h⁻¹ group required a temporary infusion cessation due to side-effects (predominantly hand numbness) (P=0.02). CONCLUSIONS: Continuous interscalene ropivacaine 0.2% 2 ml h⁻¹ with mandatory 6 hourly (and PRN) boluses provides similar analgesia after rotator cuff repair but with reduced side-effects compared with 5 ml h⁻¹ with PRN only boluses.

Postoperative analgesia for shoulder surgery: a critical appraisal and review of current techniques.

Shoulder surgery is well recognised as having the potential to cause severe postoperative pain. The aim of this review is to assess critically the evidence relating to the effectiveness of regional anaesthesia techniques commonly used for postoperative analgesia following shoulder surgery. Subacromial/intra-articular local anaesthetic infiltration appears to perform only marginally better than placebo, and because the technique has been associated with catastrophic chondrolysis, it can no longer be recommended. All single injection nerve blocks are limited by a short effective duration. Suprascapular nerve block reduces postoperative pain and opioid consumption following arthroscopic surgery, but provides inferior analgesia compared with single injection interscalene block. Continuous interscalene block incorporating a basal local anaesthetic infusion and patient controlled boluses is the most effective analgesic technique following both major and minor shoulder surgery. However, interscalene nerve block is an invasive procedure with potentially serious complications and should therefore only be performed by practitioners with appropriate experience.

deFOG--A real time system for detection and unfreezing of gait of Parkinson's patients.

Freezing of gait (FOG) is a common complication in movement disorders, typically associated with the advanced stages of Parkinson's disease. Auditory cues might be used to facilitate unfreezing of gait and prevent fall related injuries. We present a wearable, unobtrusive system for real-time gait monitoring, which consists of an inertial wearable sensor and wireless headset for the delivery of acoustic cues. The system recognizes FOG episodes with minimum latency and delivers acoustic cues to unfreeze the gait. We present design of a system for the detection and unfreezing of gait (deFOG), and preliminary results of the feasibility study. In a limited test run of 4 test cases the system was able to detect freezing of gait with average latency of 332 ms, and maximum latency of 580 ms.

Ambulatory continuous femoral analgesia for major knee surgery: a randomised study of ultrasound-guided femoral catheter placement.

Needle-nerve stimulation has a false negative motor response rate, which may increase needle passes. This prospective, randomised study tested the hypothesis that femoral nerve catheters placed with ultrasound-only guidance could provide comparable postoperative analgesia to those placed using a conventional nerve stimulation endpoint. Patients presenting for major knee surgery to the lead investigator were recruited. Needles introduced for femoral nerve catheter placement were initially guided with 'oblique' out-of-plane ultrasound imaging but were then prospectively randomised to either an ultrasound (n = 21) or nerve stimulation (n = 24) endpoint. An elastomeric infusion of ropivacaine 0.2% 2 ml/hour with as required hourly 5 ml boluses was continued for > 48 hours in hospital and/or in the home. Needle time under the skin and numerical rating pain score during insertion were recorded. Patients were questioned for worst numerical rating pain score, the need for supplementary ropivacaine boluses and tramadol on postoperative days one and two. There was no difference in the worst numerical rating pain score at rest and on movement and the requirement for supplementary ropivacaine boluses or tramadol during the first 48 postoperative hours. The median (quartiles) needle time under the skin was 58 seconds (51 to 76) in the ultrasound group and 120 seconds (95 to 178) in the nerve stimulation group (P = 0.001). The median (quartiles) insertion numerical rating pain score was 2 (0 to 2) in the ultrasound group and 4 (2 to 6) in the nerve stimulation group (P = 0.014). Femoral nerve catheters placed for major knee surgery using an ultrasound endpoint provided postoperative analgesia comparable to that obtained when using a nerve stimulation endpoint and were associated with a reduction in both needle manipulations and procedure-related pain.

Speed of onset of 'corner pocket supraclavicular' and infraclavicular ultrasound guided brachial plexus block: a randomised observer-blinded comparison.

This prospective, randomised, observer blinded study compared the onset time of brachial plexus block using 2% lidocaine 25-30 ml with adrenaline 5 microg.ml(-1) into the 'corner pocket' inferolateral/lateral to the subclavian artery (supraclavicular, n = 30) or to a triple point injection around the axillary artery (infraclavicular, n = 30). Mean (SD) onset time for complete pinprick sensory blockade assessed by a blinded observer in all four distal nerves was similar in both groups: supraclavicular = 22 (9.4) min, infraclavicular = 21 (7.1) min, p = 0.59. Complete sensory blockade in all four nerve territories at 30 min was achieved in 57% in group supraclavicular and 70% in group infraclavicular (p = 0.28). Painless surgery without the requirement for block supplementation was higher in group infraclavicular (28/30, 93%) compared with group supraclavicular (19/30, 67%; p = 0.01). Of the 11 failures in group supraclavicular, nine were due to incomplete ulnar nerve territory anaesthesia. These results do not support the concept of rapid onset successful supraclavicular block via a simple ultrasound-guided local anaesthetic injection inferolateral to the subclavian artery.

Regional anaesthesia elastomeric pump performance after a single use and subsequent refill: a laboratory study.

Ambulatory local anaesthetic delivery systems are often limited by a short effective duration of infusion. Prolonging nerve blockade by substituting a new pump as recommended by the manufacturers, represents a substantial consumable item cost ($US 300-500). We therefore evaluated the flow delivery performance of 31 single model elastomeric devices (all with a 2 ml.h(-1) background and 5 ml every hour bolus capability) that had been filled, used in clinical practice and then refilled in the laboratory. For the second infusion, there was a pattern of over-infusion (< 10 ml.h(-1)) in the first hour; however, all pumps depreciated to < 150% of predicted by the second hour. The subsequent performance of all pumps was not only within safe limits, but also predominantly within the range (background infusion +/- 15%, bolus +10/-20%) specified by the manufacturer for primary infusion. We conclude that this elastomeric regional anaesthesia pump design performs satisfactorily after having been refilled following a single previous use.

Analgesic effectiveness of ropivacaine 0.2% vs 0.4% via an ultrasound-guided C5-6 root/superior trunk perineural ambulatory catheter.

BACKGROUND: In this prospective, randomized, triple-blinded study, we tested the hypothesis that a 48 h continuous C5-6 root/superior trunk patient-controlled infusion of ropivacaine 0.4% would provide superior analgesia after shoulder surgery compared with the same infusion of ropivacaine 0.2%. METHODS: Patients presenting for painful shoulder surgery were recruited. A perineural catheter was placed under ultrasound guidance immediately adjacent to the C5-6 roots/superior trunk. Ropivacaine 5 mg ml(-1) (30 ml) was administered via this catheter before surgery under general anaesthesia. At the end of surgery, patients were randomized to receive ropivacaine 2 mg ml(-1) (0.2%) (n=32) or 4 mg ml(-1) (0.4%) (n=33) via an elastomeric pump delivering 2 ml h(-1) with on-demand patient-controlled boluses of 5 ml as required. Acetaminophen and diclofenac were administered if any postoperative pain occurred, ropivacaine boluses for a numerical rating pain score (NRPS, 0-10) of >2, and rescue tramadol for an NRPS >3. All patients were phoned on postoperative days 1 and 2 and questioned for indices of treatment effectiveness and adverse effects. RESULTS: NRPS, patient ropivacaine demands, and supplemental tramadol consumption were similar in each group [median 'average daily pain' days 1/2 (0.2%=1/3, 0.4%=2/3)]. Episodes of an insensate/densely blocked arm occurred only with ropivacaine 0.4% (5 vs 0 episodes, P=0.05). Satisfaction (numerical rating scale, 0-10) was higher for ropivacaine 0.2% [mean difference (95% confidence interval)=1.3 (0.3-2.4), P=0.01)]. CONCLUSIONS: After major shoulder surgery, ropivacaine 0.2% at 2 ml h(-1) with on-demand 5 ml boluses administered via an ultrasound-guided C5-6 root/superior trunk perineural catheter produces similar analgesia, but higher patient satisfaction compared with ropivacaine 0.4%. TRIAL REGISTRATION: ANZCTR: ACTRN12608000591358. URL: www.anzctr.org.au/registry/trial_review.aspx?ID=83028.

Neurological complication analysis of 1000 ultrasound guided peripheral nerve blocks for elective orthopaedic surgery: a prospective study.

Little data exists regarding the frequency of neurological complications following ultrasound guided peripheral nerve blockade. Therefore, we studied single injection and continuous ultrasound guided interscalene, supraclavicular, infraclavicular, femoral and sciatic nerve blocks in patients undergoing orthopaedic extremity surgery. All patients were contacted during postoperative weeks 2-4 and questioned for numbness or altered sensation anywhere in the involved extremity, and pain or weakness unrelated to surgery. The presumed aetiology of symptoms was based on the collective agreement of principal investigator, primary surgeon and a neurologist. Multivariate analysis was performed for characteristics potentially important in the causation of neurological complications. Of 1010 consecutive blocks, successful follow up between weeks 2 and 4 occurred in 98.6%. New, all-cause, neurological symptoms were present in 56/690 blocks (8.2%) at day 10, 37/1010 (3.7%) at 1 month and 6/1010 (0.6%) at 6 months. Most symptoms were due to causes unrelated to the block. Of 452 patients directly questioned at the time of the block, new neurological symptoms were more common in patients who experienced procedure-induced paraesthesia (odds ratio = 1.7, p = 0.029). The postoperative neurological symptom rate in this series is very similar to those previously reported following traditional techniques.

Ultrasound-guided transversus abdominis plane block for neonatal abdominal surgery.

This paper describes four neonates having abdominal procedures with intraoperative and early postoperative analgesia provided by a transversus abdominis plane regional block. Analgesia for neonatal upper and mid-abdominal surgery usually involves regional anaesthesia and/or systemic opioid. All these analgesia techniques have problems specific to the neonatal period. Neonates are sensitive to the respiratory depressant effects of systemic opioid, while the low threshold for local anaesthetic toxicity limits regional anaesthesia/analgesia, which in neonatal upper abdominal surgery is often limited to local anaesthetic infiltration. The transversus abdominis plane block has been shown to provide effective analgesia following a variety of abdominal surgeries in both adults and children. We report four neonates who underwent minor or major abdominal surgery under general anaesthesia supplemented by ultrasound-guided transversus abdominis plane block. Perioperative opioids were administered to one neonate who required postoperative ventilation. Ultrasound-guided transversus abdominis plane bock is a technically feasible alternative to local anaesthetic wound infiltration in the neonate and warrants further evaluation.