Plantar compartment block for hallux valgus surgery: a proof-of-concept anatomic and clinical study.

BACKGROUND: Hallux valgus surgery is associated with moderate to severe postoperative pain. We hypothesized that a plantar compartment block may be a good technique for postoperative analgesia. We describe an anatomic approach to ultrasound-guided plantar compartment block and assess the clinical efficacy of the block for outpatient surgery. METHODS: The anatomic study was aimed to describe the plantar compartment, using both dissection methods and imaging, and to define a volume of local anesthetic. Patients scheduled for hallux valgus surgery with a popliteal sciatic nerve block, and combined plantar compartment and peroneal blocks were included in the clinical study. Data on attaining the criteria for rapid exit from the outpatient center, duration of sensory and analgesic block, visual analog scale (VAS) values for postoperative pain at rest and during movement, and the consumption of morphine as rescue analgesia were recorded. RESULTS: Plane-by-plane dissections and cross-sections were done in five cadaveric lower limbs. The medial calcaneal nerve divides into medial plantar and lateral plantar nerves in the upper part of the plantar compartment. These nerves were surrounded by 5 mL of colored gelatin, and 10 mL of injectates dye spread to the medial calcaneal branches. Thirty patients (26 women) were included in the clinical study. There were no failures of surgical block. Ninety per cent of patients successfully passed functional testing for ambulatory exit from the center within 5 hours (25th-75th centiles, 3.8-5.5 hours). The median duration of plantar compartment sensory block was 17.3 hours (10.5-21.5 hours), and the first request for rescue analgesic was 11.75 hours (10.5-23 hours) after surgery. The median VAS score for maximum pain reported within the 48-hour period was 2 (1-6). Twelve patients received 2.5 mg (0-5 mg) of morphine on day 1. Patients were highly satisfied and no adverse events were noted. CONCLUSIONS: This anatomic description of the ultrasound-guided plantar compartment block reported the injection area to target the medial and lateral plantar nerves with 5 mL of local anesthetic. Normal walking without assistance is attained rapidly with this regional anesthesia technique, and the time to request postoperative analgesia after hallux valgus surgery is long. TRIAL REGISTRATION NUMBER: NCT03815422.

Remote transmission monitoring for postoperative perineural analgesia after major orthopedic surgery: A multicenter, randomized, parallel-group, controlled trial.

STUDY OBJECTIVE: After surgery, patients reported the delay in receiving help as the primary factor for poorly controlled pain. This study aimed to compare the effectiveness of patient management through two communication modalities: remote transmission (RT) versus bedside control (BC). We hypothesized that using remote technology for pump programming may provide the best postoperative infusion regimen for the patient's self-assessment of pain and adverse events. DESIGN: A multicenter, randomized, parallel-group, controlled trial. SETTING: Anesthesiology department and orthopedic surgery ward at three university hospitals. PATIENTS: Eighty patients undergoing orthopedic surgery with postoperative perineural patient-controlled analgesia were included. INTERVENTIONS: Two groups (n = 40 for each group) were formed by randomization. In the postoperative period, perineural analgesia was followed up via an RT system or BC for 72 h. MEASUREMENTS: A nurse assessed daily pain, sensory and motor blocks and adverse events. Patients completed a questionnaire three times a day and alerted for any problem according to the group (RT system or nurses' follow-up). On the third postoperative day, the nurse removed the catheter, completed the final assessment, and collected the historical data from the pump. A physician's shorter response time to change the patient control analgesia (PCA) program was the primary endpoint. RESULTS: Of the 80 patients, 71 were analyzed (34 were randomized to the RT group and 37 to the BC group). Fifty-eight pump setting changes were noted. Analysis of repeated evaluations shows that mean time (SD) to change the PCA pump settings was significantly lower in the RT group (20 min (22.3 min)) than in the BC group (55.9 min (71.1 min)); mean difference [95% CI], -35.9 min [-74.3 to 2.4]); ß estimation [95% CI], -34 [-63 to -6], p = 0.011). Pain relief, sensory and motor blocks did not differ between the groups: ß estimation [95% CI], 0.1 [-0.4 to 0.6], p = 0.753; 0.5 [-0.4 to 1.4], p = 0.255; 0.9 [-0.04 to 1.8], p = 0.687, respectively. ß = -34 [-63 to -6], p = 0.011). The consumption of ropivacaine, nurse workload and the cost of the analgesia regimen decreased in the RT group. No differences were noted in satisfaction scores or complication rates. CONCLUSIONS: The response time for the physician to change the PCA program when necessary was shorter for patients using RT and alerts to the physician were more frequent compared with spot checks by nurses. RT helps to decrease nurses' workload, ropivacaine consumption, and costs but did not affect postoperative pain relief, complication rate, or patient-reported satisfaction score. IRB CONTACT INFORMATION: Comité de Protection des Personnes, Sud Méditerranée III, Montpellier-Nîmes, France, registration number EudraCT A01698-35. CLINICAL TRIAL NUMBER: ClinicalTrials.gov ID:NCT02018068 PROTOCOL: The full trial protocol can be accessed at Department of Anesthesiology and Critical Care Medicine, Medical Research and Statistics Unit, Lapeyronie University Hospital, Avenue Doten G Giraud, Montpellier, France. s-bringuierbranchereau@chu-montpellier.fr.

Impact of multiple nerves blocks anaesthesia on intraoperative hypotension and mortality in hip fracture surgery intermediate-risk elderly patients: A propensity score-matched comparison with spinal and general anaesthesia.

BACKGROUND: A Hip fracture in the intermediate-risk elderly patient is common and associated with a high rate of postoperative morbidity and mortality. There is a lack of consensus on the optimal anaesthetic technique but there is a clear association between intraoperative hypotension and postoperative morbidity and mortality. We aimed to compare the haemodynamic stability of three anaesthesia techniques: general anaesthesia (GA), continuous spinal anaesthesia (CSA), and multiple nerve blocks (MNB). METHODS: The primary outcome was the occurrence of intraoperative hypotension defined by a 30% decrease in mean arterial pressure (MAP) from baseline. Secondary outcomes included incidence of hypotension under 50 mmHg of MAP, time spent below MAP 50 mmHg, use of vasopressors, in-hospital and 30-day mortality. A propensity score-matched analysis was performed. RESULTS: After screening and application of the exclusion criteria, 593 patients undergoing hip fracture surgery between the 1st of January 2015 and the 31st of December 2016 were included. The propensity score match analysis selected 43 patients in each group. The incidence of hypotension was significantly higher in the GA group than in the MNB and CSA groups: 39 (90%), 22 (51%), and 23 (53.5%), respectively; p < 0.0001. The incidence of MAP < 50 mmHg (59.5%, 23.3%, and 16.3%; p < 0.0001) and the use of vasopressors (93%, 39.5%, and 25.6%; p < 0.0001) were increased significantly in the GA group. With the GA group as a reference, odds ratios were reported in the MNB group at 0.08 [0.022-0.30] (p = 0.0002) for hypotension episodes; 0.17 [0.04-0.66] (p = 0.01) for hypotension < 50 mmHg for more than 3 min and 0.049 [0.013-0.018] (p < 0.0001) for use of vasopressors. The duration of hospital stay, postoperative complications, in-hospital and 30-day mortality rates did not differ significantly between the groups. CONCLUSION: CSA and MNB provide better haemodynamic stability than GA. However, whatever the anaesthesia technique used, the mortality rates do not change even if MNB leads to less hypotension. IRB contact information: CERAR IRB 00010254-2016-118. Clinical Trial Number: ClinicalTrials.gov. ID: NCT03356704.

Combination of real-time needle-tip pressure sensing and minimal intensity stimulation limits unintentional intraneural injection during an ultrasound-guided peripheral nerve block procedure: A randomized, parallel group, controlled trial.

STUDY OBJECTIVE: Ultrasound guidance does not eliminate the risk of intraneural injection, which must be avoided during PNB. Combining ultrasound guidance (USG), nerve stimulation (NS), and injection pressure monitoring is advocated to prevent nerve injury during PNB. We hypothesized that combining patient-tailored dynamic NS and real-time pressure sensing (RTPS) could reduce the incidence of intraneural injection and nerve puncture during USG PNB compared with a traditional fixed thresholds (Control) procedure. DESIGN: Randomized, prospective study. SETTING: Operating room. PATIENTS: One hundred ASA physical status I to III patients undergoing orthopedic surgery. INTERVENTIONS: Patient anesthetized using axillary, sciatic or femoral USG PNB were randomized to the PresStim group (Dynamic RTPS and NS set at 1.5 mA then decreased; n = 50) or Control group (fixed thresholds for in-line pressure mechanical manometer and NS at 0.2 mA; n = 50). MEASUREMENTS: Procedural ultrasound images and videos were recorded, stored and reviewed in random order by two experts in ultrasound-guided PNB blinded to the group. They noted the needle-to-nerve relationship and intraneural injection for all blocked nerves. MAIN RESULTS: One hundred and twenty-three USG PNBs were performed (56 axillary brachial plexus blocks, 40 femoral nerve blocks and 27 sciatic popliteal nerve blocks); 235 blocked nerves and videos were recorded and analyzed (PresStim, 118; Control, 117). Less paresthesia was noted in the PresStim group (12.7%) compared with the Control group (18.8%). The risk of intraneural injection was significantly higher in the Control group (odds ratio [OR], 17.1; 95% confidence interval [CI], 2.2-135, P = 0.007). The risk of nerve puncture (OR, 22.7; 95% CI, 2.9-175, p = 0.003) and needle-nerve contact (OR, 4.7; 95% CI, 2.4-9.5, p < 0.001) was significantly higher in the Control group than the PresStim group. CONCLUSIONS: Under the conditions of the study, dynamic triple monitoring combining RTPS, NS and USG decreases intraneural injection and unintentional needle-nerve contact and puncture during a PNB procedure.

An uncommon cause of nerve stimulator's malfunction during a dual guidance lumbar plexus block: A technical brief report and an algorithm for prevention of complications.

Posterior Lumbar plexus block (PLPB) combined with an ipsilateral sacral plexus block is a valuable anaesthetic technique in patients undergoing hip fracture surgery. PLPB is performed through the acoustic window of the lumbar ultrasound trident and the position of the needle tip, before injection of LA, was confirmed by observing quadriceps femoris muscle contraction to peripheral nerve stimulation (i.e., dual guidance). We report an uncommon cause of nerve stimulator malfunction that might impair block performance and promote complications. We add an algorithm to limit the risk of complications.

Real-Time Injection Pressure Sensing and Minimal Intensity Stimulation Combination During Ultrasound-Guided Peripheral Nerve Blocks: An Exploratory Observational Trial.

BACKGROUND: Nerve damage can occur after peripheral nerve block (PNB). Ultrasound guidance does not eliminate the risk of intraneural injection or nerve injury. Combining nerve stimulation and injection pressure (IP) monitoring with ultrasound guidance has been suggested to optimize needle tip location in PNB. In this prospective observational study, we hypothesized that measured pairs of IP and minimum intensity of stimulation (MIS) might differentiate successive needle tip locations established by high-resolution ultrasound during PNB. METHODS: For this exploratory study, 240 observations for 40 ultrasound-guided PNBs were studied in 28 patients scheduled for orthopedic surgery. During the progression of the needle to the nerve observed by ultrasonography, the IP was measured continuously using a computerized pressure-sensing device with a low flow rate of solution. Stimulation thresholds and electrical impedance were obtained by an impedance analyzer coupled to the nerve stimulator at 6 successive needle positions. The median (quartile) or mean (95% confidence interval [CI]) was reported. A mixed model analysis was used, and the sample was also explored using a classification and regression tree (CART) algorithm. RESULTS: Specific combinations of IP and MIS were measured for subcutaneous, epimysium contact, intramuscular, nerve contact (231 mm Hg [203-259 mm Hg] and 1.70 mA [1.38-2.02 mA]), intraneural location (188 mm Hg [152-224 mm Hg] and 0.58 mA [0.46-0.70 mA]), and subparaneural location (47 mm Hg [41-53 mm Hg] and 1.35 mA [1.09-1.61 mA]). The CART algorithm shows that the optimal subparaneural needle tip position might be defined by the lowest pressure (<81.3 mm Hg) and MIS (<1.5 mA) cutoffs. CONCLUSIONS: Our exploratory study evaluated concepts to generate hypotheses. The combinations of IP and MIS might help the physician during a PNB procedure. A low IP and low MIS might confirm a subparaneural location, and a high IP and a low MIS might be an alert for the intraneural location of the needle tip.

Injection pressure monitoring during peripheral nerve blocks: from bench to operating theatre.

BACKGROUND: Nerve damage can occur after ultrasound-guided peripheral nerve block (PNB). Injection pressure monitoring could improve the safety of PNB. The aim was to analyse parameters affecting pressure measurements during PNB. METHODS: The flow characteristics of needles connected to a pressure-sensing device were evaluated. Needles were placed under ultrasound guidance extra or epineurally in nerves/plexus of fresh cadavers. Using three flow rates, 4 mL of saline was injected and plateau pressure was measured. Finally, orthopaedic surgery patients receiving PNB were enrolled for an observational real-time pressure monitoring study. During PNB, periods with pressure > 50 mmHg were noted (high pressure ≥ 750 mmHg). A blinded investigator recorded injection pressure curves and peak pressure. RESULTS: The needle diameter influenced the injection pressure (ß = 66.8; P < 0.0001). Non-echogenic needles increased the injection pressure (ß = 82; P = 0.0009) compared with echogenic needles. Cadaver injection pressure was higher for intraneural (255 [122.5-555] mmHg) versus extraneural needle tip location (90 [50-158] mmHg; P < 0001); for high flow (9.6 mL/min; 470 [265; 900] mmHg) versus low flow (1.2 mL/min; 120 [71-250] mmHg) (P < 0.001) and for cervical roots (900 mmHg, intraneurally) compared with nerves (300 mmHg, intraneurally). In 37 patients and 61 procedures, there were 7 [1-18] peaks of injection pressure per procedure. Pressure was noted > 750 mmHg during 13.80% of the procedural time. CONCLUSIONS: Needle diameter, needle tip location, type of nerve/plexus, flow rates, and the anaesthetist can have a significant effect on injection pressure values and monitoring. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT03430453.

Impact of Chloroprocaine on the Eligibility for Hospital Discharge in Patients Requiring Ambulatory Surgery Under Spinal Anesthesia: An Observational Multicenter Prospective Study.

INTRODUCTION: This observational study was designed to assess the use of spinal anesthesia with chloroprocaine in the context of ambulatory surgery. METHODS: A prospective, multicenter, observational study was carried out among 33 private or public centers between May 2014 and January 2015 and adult patients, scheduled for a short ambulatory surgery under spinal anesthesia with chloroprocaine. The primary outcomes were anesthetic effectiveness, defined as performance of the whole surgical procedure without any additional anesthetic agent, and the time to achieve eligibility for hospital discharge. Secondary outcomes were the effect of chloroprocaine on motor and sensory blocks, patients' satisfaction, and the use of analgesics in the first 24 h after surgery. RESULTS: Among the 615 enrolled patients, 56% were male, the mean age was 47.2 ± 15.2 years, and most patients had an ASA (American Society of Anesthesiologists) status of 1 (63.7%). Main surgical procedures performed were orthopedic (62.6%) and gynecologic (16.1%), and the mean duration of surgery was 26.7 ± 16.7 min. The overall anesthetic success rate was 93.8% (95% CI [91.5%; 95.6%]) for the 580 patients with available data for primary criteria. The failure rate was lower than 7% for all surgical procedures, except for gynecologic surgery (14.8%; 95% CI [8.1%; 23.9%]). The average times of eligibility for hospital discharge and effective discharge were 252.7 ± 82.7 min and 313.8 ± 109.9 min, respectively. The time of eligibility for hospital discharge is defined as the recovery of the patient's normal clinical parameters and the time of effective discharge is defined as the time for the patient to leave the hospital after surgery. Eligibility for patient's discharge was achieved more rapidly in private than public hospitals (236.3 ± 77.2 min vs. 280.9 ± 80.7 min, respectively, p < 0.001). CONCLUSIONS: This study showed positive results on the effectiveness of chloroprocaine as a short-duration anesthetic and could be used to reduce the time to achieve eligibility for hospital discharge. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02152293. Registered on May 6, 2014. Date of enrollment of the first participant in the trial May 7, 2014.

Factors Determining the Choice of Spinal Versus General Anesthesia in Patients Undergoing Ambulatory Surgery: Results of a Multicenter Observational Study.

INTRODUCTION: Available short-acting intrathecal anesthetic agents (chloroprocaine and prilocaine) offer an alternative to general anesthesia for short-duration surgical procedures, especially ambulatory surgeries. Factors determining the choice of anesthesia for short-duration procedures have not been previously identified. METHODS: This observational, prospective, multicenter, cohort study was conducted between July 2015 and July 2016, in 33 private or public hospitals performing ambulatory surgery. The primary objective was to determine the factors influencing the choice of anesthetic technique (spinal or general anesthesia). Secondary outcomes included efficacy of the anesthesia, time to hospital discharge, and patient satisfaction. RESULTS: Among 592 patients enrolled, 309 received spinal anesthesia and 283 underwent general anesthesia. In both study arms, the most frequently performed surgical procedures were orthopedic and urologic (43.3% and 30.7%, respectively); 66.1% of patients were free to choose their type of anesthesia, 21.8% chose one of the techniques because they were afraid of the other, 16.8% based their choice on the expected ease of recovery, 19.2% considered their degree of anxiety/stress, and 16.9% chose the technique on the basis of its efficacy. The median times to micturition and to unassisted ambulation were significantly shorter in the general anesthesia arm compared with the spinal anesthesia arm (225.5 [98; 560] min vs. 259.0 [109; 789] min; p = 0.0011 and 215.0 [30; 545] min vs. 240.0 [40; 1420]; p = 0.0115, respectively). The median time to hospital discharge was equivalent in both study arms. In the spinal anesthesia arm, patients who received chloroprocaine and prilocaine recovered faster than patients who received bupivacaine. The time to ambulation and the time to hospital discharge were shorter (p < 0.001). The overall success rate of spinal anesthesia was 91.6%, and no significant difference was observed between chloroprocaine, prilocaine, and bupivacaine. The patients' global satisfaction with anesthesia and surgery was over 90% in both study arms. CONCLUSIONS: Patient's choice, patient fear of the alternative technique, patient stress/anxiety, the expected ease of recovery, and the efficacy of the technique were identified as the main factors influencing patient choice of short-acting local anesthesia or general anesthesia. Spinal anesthesia with short-acting local anesthetics was preferred to general anesthesia in ambulatory surgeries and was associated with a high degree of patient satisfaction. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02529501. Registered on June 23, 2015. Date of enrollment of the first participant July 21, 2015.

Perifascial plane versus perineural approaches for ultrasound-guided axillary block: go to the simplest?

BACKGROUND: Ultrasound-guided axillary block is widely used in daily practice for upper limb orthopedic surgery. A simple, safe, efficacious and time-saving technique is mandatory to optimize surgical turnover and costs. In this perspective, we compared, in a randomized, single-blinded study, a standardized perifascial technique and the selective perineural technique. METHODS: Forty-two patients scheduled for elective hand surgery were randomly assigned to receive 20 mL of 10 mg/mL mepivacaine, either selectively around each of the radial, median, ulnar and musculocutaneous nerves (perineural group) or along the latissimus dorsi and superficial axillary fascia (perifascial group). The primary outcome was the procedure performance time in both groups. Secondary goals were the number of needle passes, a per-procedure evaluation of the performance on a visual analogue scale ranging from 0 to 10, the success rate and the incidence of adverse events. RESULTS: Performance time was significantly reduced in the perifascial group (3.6 vs. 6.5 min, P<0.001), with fewer needle passes (3 vs. 6, P<0.001) and a simpler procedure performance (8.5 vs. 7.6, P=0.02). No vascular punctures or neurologic deficits were reported. Surgical anesthesia (95% in both groups) and complete anesthetic success (perifascial 81% vs. perineural 95%) were similar. CONCLUSIONS: We reported that the ultrasound-guided axillary perifascial block is easier to perform and saves procedural time compared to the classic perineural technique. Considering the same anesthetic success rate in both groups, the perifascial plane technique should be considered a daily practice technique and the first level of learning procedure for axillary block.

Catheter use in regional anesthesia: pros and cons.

Continuous peripheral nerve blocks refer to a local anesthetic solution administered via perineurally placed catheters in an effort to extend the benefits of a single-shot peripheral nerve block. They offer several advantages in the postoperative period including excellent analgesia, reduced opioid consumption and associated side effects, enhanced rehabilitation and improved patient satisfaction. The current trend towards less invasive, one-day surgery and enhanced recovery programs may decrease the requirement of catheter use. Prolonged motor block in particular is associated with undesirable outcomes. Should we routinely use continuous peripheral nerve blocks in our daily practice? This PRO-CON debate aims at answering the question from the experts' perspectives. Fascial compartment and wound catheters are outside the scope of this debate.

Spinal anaesthesia in outpatient and conventional surgery: A point of view from experienced French anaesthetists.

INTRODUCTION: The objective of this investigation was to evaluate the practice of spinal anaesthesia among French anaesthetists in inpatient and outpatient settings. METHODS AND MATERIALS: A questionnaire was sent to members of the French Association of Anaesthetists involved in regional anaesthesia during the first 4months of 2015. The questionnaire included items on the practice of spinal anaesthesia (type of needle, local anaesthetic available, puncture and disinfection techniques, etc.) and on the anaesthetic techniques usually used in 5 surgical situations eligible for outpatient surgery (knee arthroscopy, inguinal hernia, transobturator tape, haemorrhoids, varicose veins in the lower limbs). RESULTS: Responses from 703 anaesthesiologists were analysed. Spinal anaesthesia was usually performed in a sitting position (76%) using a Whitacre needle (60%) with a 25 G (57%) diameter. Ultrasound before puncture was reported in 26% of cases due to obesity or spinal abnormalities. Among the 5 surgical situations eligible for outpatient spinal anaesthesia, the technique was typically proposed in 29-49% of cases. Bupivacaine was the most used local anaesthetic. Concerns over delays in attaining readiness for hospital discharge, urine retention, operation length, and surgeon's preference were the main reasons for choosing another anaesthetic technique in these situations. DISCUSSION: New local anaesthetics are beginning to be used for outpatient spinal anaesthesia due to their interesting pharmacodynamic profile in this context. This study will provide a basis for evaluating future changes in practice.

Percutaneous Needle Tenotomy for the Treatment of Muscle and Tendon Contractures in Adults With Brain Damage: Results and Complications.

OBJECTIVE: To study the results and complications of percutaneous needle tenotomy for superficial retracted tendons in patients with brain damage. DESIGN: Prospective observational study. SETTING: University hospital. PARTICIPANTS: Patients with severe brain damage (N=38; mean age, 60.7y; age range, 24-93y; 21 women) requiring surgical management of contractures and eligible for percutaneous needle tenotomy were enrolled between February 2015 and February 2016. INTERVENTIONS: The percutaneous needle tenotomy gesture was performed by a physical medicine and rehabilitation physician trained by an orthopedic surgeon, under local or locoregional anesthesia. Treated tendons varied among patients. MAIN OUTCOME MEASURES: All patients were evaluated at 1, 3, and 6 months to assess surgical outcomes (joint range of motion [ROM], pain, and functional improvement) while screening for complications. RESULTS: Improvements in ROM (37/38) and contractures-related pain (12/12) were satisfactory. Functional results were satisfactory (Goal Attainment Scale score ≥0) for most patients (37/38): nursing (n=12), putting shoes on (n=8), getting in bed or sitting on a chair (n=6), verticalization (n=7), transfers and gait (n=8), and grip (n=2). Five patients had complications related to the surgical gesture: cast-related complications (n=2), hand hematoma (n=2), and cutaneous necrosis of the Achilles tendon in a patient with previous obliterative arteriopathy of the lower limbs (n=1). CONCLUSIONS: Percutaneous needle tenotomy yields good results in the management of selected superficial muscle and tendon contractures. The complications rate is very low, and this treatment can be an alternative to conventional surgery in frail patients with neurologic diseases.

Diagnosis of Postoperative Urinary Retention Using a Simplified Ultrasound Bladder Measurement.

BACKGROUND: In this study, we sought to determine whether a simplified ultrasound measurement of the largest transverse diameter, using a standard ultrasound machine, could be used to diagnose postoperative urinary retention (POUR). This method may replace expensive bladder volume measuring devices or a more complex ultrasound procedure (involving the measurement of 3 bladder diameters). METHODS: Patients at risk of POUR if unable to void after orthopedic surgery were evaluated in the postanesthesia care unit before discharge. Bladder diameter was first measured using a portable ultrasound device (Vscan®; GE Healthcare, Wauwatosa, WI). An automated evaluation of bladder volume was then performed (Bladderscan® BVI 3000; Diagnostic Ultrasound, Redmond, WA). Finally, when a bladder catheterization was performed, the actual urinary volume was measured. The main outcome was a bladder volume ≥600 mL as measured using the automated ultrasound scanner (Bladderscan BVI 3000) or by catheterization. Correlations between bladder volumes and diameter were studied and receiver operating characteristic curves were constructed to determine the performance in predicting a bladder volume ≥600 mL. A "gray zone" approach was developed because a single cutoff value may not always be clinically significant. RESULTS: One hundred patients were included and underwent a Bladderscan measurement. Urinary volume after catheterization was obtained in 49 patients. A significant correlation was found between the largest transverse diameter and urinary volumes assessed by the 2 methods (Bladderscan and catheterization). Pearson correlation coefficients were r = 0.80 (95% confidence interval [CI], 0.72-0.86; P < 0.001) and r = 0.79 (95% CI, 0.65-0.88; P < 0.001), respectively. The area under the receiver operating characteristic curves for the prediction of a bladder volume ≥600 mL were 0.94 (95% CI, 0.88-0.98) and 0.91 (95% CI, 0.79-0.97), respectively, for urinary volumes assessed by Bladderscan and catheterization. The optimal cutoff value was 9.7 cm for both methods. The gray zone was narrow, ranging from 9.7 to 10.7 cm thus limiting inconclusive measurements. CONCLUSIONS: A simple ultrasound measurement of the largest transverse bladder diameter seemed to be helpful to exclude or confirm POUR.

Subparaneural versus circumferential extraneural injection at the bifurcation level in ultrasound-guided popliteal sciatic nerve blocks: a prospective, randomized, double-blind study.

BACKGROUND: The ideal spread of local anesthetic for effective, rapid, and safe sciatic nerve block is debated. We hypothesized that subparaneural ultrasound-guided injection results in faster onset and has a better success rate than extraneural circumferential spread. METHODS: Patients undergoing elective tibial, foot, and ankle surgery with popliteal sciatic nerve blocks were prospectively enrolled. After randomization, the needle tip position was adjusted to ensure circumferential extraneural or subparaneural spread; 0.3 mL/kg of mepivacaine 10 mg/mL was injected. Post hoc video analysis was used to group the patients according to extraneural, subparaneural, and unintentional intraepineural spread. RESULTS: There were 26 (43.3%) patients in the subparaneural group and 22 (36.7%) in the extraneural group. Block onset time was shorter in the subparaneural group than in the extraneural group (11 [3-21] minutes; mean [95% confidence interval], 11 [8.97-13.02] minutes and 17 [6-30] minutes; mean [95% confidence interval] 18.37 [14.17-22.57] minutes, respectively; P = 0.002). The duration of sensory blockade increased (397 [178-505] minutes vs 265 [113-525] minutes; P = 0.04). The success rate of the block also increased. Unintentional intraepineural injection occurred in 8% of patients (3 patients in the subparaneural group and 1 patient in the extraneural group; NS). Block onset time was shorter than for the subparaneural and extraneural groups (6 [3-12] minutes, 12 [3-21] minutes, and 18 [6-30] minutes; P = 0.01). CONCLUSIONS: A subparaneural injection accelerated the onset time and increased the duration of tibial nerve sensory blockade compared with circumferential extraneural injection. With unintentional intraepineural spread, the onset time was significantly shorter than for the other groups.

Management of mediastinal syndromes in pediatrics: a new challenge of ultrasound guidance to avoid high-risk general anesthesia.

Adverse events associated with anesthetic management of anterior mediastinal masses in pediatrics are common. To avoid an extremely hazardous general anesthesia, the use of real-time ultrasonography offers an effective alternative in high-risk cases. We report the anesthetic management including a light sedation and ultrasound guidance for regional anesthesia, surgical node biopsy, and placement of a central venous line in two children with an anterior symptomatic mediastinal mass. For pediatric patients with clinical and/or radiologic signs of airway compression, ultrasound guidance provides safety technical assistance to avoid general anesthesia and should be performed for the initial diagnostic and therapeutic procedures.

Case report: Three-dimensional high-resolution ultrasound-guided nerve blocks: a new panoramic vision of local anesthetic spread and perineural catheter tip location.

We report in 3 patients that high-frequency ultrasound 3-dimensional imaging enabled us to analyze anatomic variations, evaluate local anesthetic spread, and optimize a perineural catheter location by withdrawing it until its tip was appropriately positioned. This innovative technology may provide answers to different problems facing the operator performing ultrasound-guided nerve blocks. It may enhance predictability and safety aspects of peripheral nerve blocks.

The ultrasound-guided transversus abdominis plane block for anterior iliac crest bone graft postoperative pain relief: a prospective descriptive study.

BACKGROUND: Acute postoperative pain and nerve injuries frequently lead to neuropathic chronic pain after anterior iliac crest (AIC) bone graft. This prospective study evaluated postoperative pain relief after preoperative ultrasound-guided transversus abdominis plane (TAP) block for orthopedic surgery with an AIC bone harvest and the prevalence of pain chronicization at 18 months after surgery. METHODS: Thirty-three consecutive patients scheduled for major orthopedic surgery with an AIC harvest for autologous bone graft were studied. Preoperative TAP blocks were performed under in-plane needle ultrasound guidance, anterior to the midaxillary line (15 mL ropivacaine 0.33%). The extent of sensory blockade was evaluated at 20 mins with cold and light-touch tests. Pain at the iliac crest graft site was assessed at rest by visual analog scale (VAS) scores in the postanesthetic care unit, and at 1, 6, 12, 24, and 48 hrs after surgery. Time for first request of morphine and total morphine consumption were recorded. Eighteen months after surgery, each patient was interviewed by phone about the importance and localization of pain chronicization. RESULTS: Median VAS score was 0 (range, 0-7) at all periods of assessment. At 20 mins, 62.5% of the patients reported complete anesthesia, and 34% hypoesthesia. The sensory blockade extent ranged from T9 (T7-T11) to L1 (T11-L2) in median (range) values. At 18 months, 80% of patients did not complain about pain or discomfort at the iliac crest site; 20% reported pain chronicization at the iliac crest site (VAS scores 2-4). Five patients (26%) complained about numbness at the iliac crest area. CONCLUSIONS: Ultrasound-guided TAP block is an appropriate technique for postoperative analgesia after AIC bone harvest in orthopedic surgery.

Ultrasound-guided evaluation of the local anesthetic spread parameters required for a rapid surgical popliteal sciatic nerve block.

BACKGROUND: The ideal spread of local anesthetic (LA) solution around the sciatic nerve during a popliteal block remains unclear. We tested the hypothesis that a circumferential spread of LA and/or intraneural injection could lead to rapid surgical block. METHODS: Patients (n = 100) scheduled for foot or ankle surgery underwent popliteal sciatic nerve block using nerve stimulation according to Borgeat's technique and injection of ropivacaine (0.5 mL/kg). Sensory and motor blockades were assessed on the tibial nerve (TN) and common peroneal nerve (CPN) at 5, 15, and 30 mins after completion of the block and in the recovery room. A successful block was defined as a complete sensory block in TN and CPN. Changes in cross-sectional and longitudinal surfaces and diameters and the characteristics of LA spread around the nerve were noted using ultrasound. A suspected intraneural injection was defined as a 15% increase in the surface area or anteroposterior diameter of the nerve. Patients were followed up on days 1 and 7 after surgery. RESULTS: Successful block was noted in 57% of patients at 30 mins and in 88% of patients in the recovery room. A circumferential spread of LA occurred in 47% of patients and 53% had noncircumferential spread. Complete sensory block was significantly higher in the group that had a circumferential spread (73% vs 43%, P = 0.035) only at 30 mins. In the postoperative care unit, there was no difference among the groups. Separated circumferential spreads around TN and CPN were noted in 12% of patients. All of these patients had a complete sensory and motor blockade at 15 mins. Concerning intraneural injection, only the change in the anteroposterior diameter on a 6-cm length of nerve was associated with a higher success and faster onset block at 5 (P = 0.008), 15 (P = 0.02), and 30 (P = 0.05) mins. There were no clinically detectable nerve injuries at follow-up. CONCLUSION: For popliteal sciatic nerve block, circumferential spread of LA, and separation of the nerve into its 2 components are associated with rapid surgical block.

Continuous peripheral nerve blocks in clinical practice.

PURPOSE OF REVIEW: The present review highlights new insights into indications and guidance during procedures for continuous peripheral nerve blocks. RECENT FINDINGS: Continuous peripheral nerve blocks consistently provide better analgesia than traditional systemic opioid-based analgesia. The literature shows that continuous peripheral nerve blocks prolong site-specific local anesthetic delivery in the outpatient setting, allow optimal analgesia, have minimal side effects, and avoid premature regression of an analgesic block. Furthermore, an improvement in patients' health-related quality of life or outcome benefits has been demonstrated. It appears that continuous peripheral nerve blocks are generally superior to intraarticular local anesthetic infusion for immediate postoperative pain, but new data demonstrate that, apart from a multimodal analgesia regimen, periarticular and intraarticular application of local anesthetics can improve early postoperative analgesia and mobilization. Finally, it seems that, only for interscalene and popliteal sciatic nerve blocks, the use of stimulating catheters slightly decreases visual analog scale scores for postoperative pain and intravenous opioid rescue analgesia. Ultrasound guidance offers the potential advantage to confirm catheter tip location. SUMMARY: Continuous peripheral nerve blocks are essential in the perioperative anesthetic management of in-hospital or ambulatory patients. Ultrasound guidance and stimulating catheters can help anesthetists during the procedure.