Cadaveric investigation of the minimum effective volume for ultrasound-guided suprainguinal fascia iliaca block

2021 ◽  
pp. rapm-2021-102563
Author(s):  
Perada Kantakam ◽  
Naraporn Maikong ◽  
Apichat Sinthubua ◽  
Pasuk Mahakkanukrauh ◽  
De Q Tran ◽  
...  
Keyword(s):  
Human Subjects ◽  
Dose Finding ◽  
Effective Volume ◽  
Ultrasound Guided ◽  
Cadaveric Specimen ◽  
Biased Coin Design ◽  
Finding Study ◽  
Fascia Iliaca Block ◽  
Internal Oblique ◽  
Previous Volume

BackgroundThis cadaveric dose-finding study investigated the minimum effective volume of dye in 90% of cases (MEV90), required to stain the femoral, lateral femoral cutaneous and obturator nerves for ultrasound-guided suprainguinal fascia iliaca block (SIFIB).MethodsIn cadaveric specimens of the lower limb, the block needle was advanced, medial to the anterosuperior iliac spine, until its tip was positioned between the internal oblique and iliacus muscles underneath the fascia iliaca. The dye was injected inside the fascia iliaca compartment. Volume assignment was carried out using a biased coin design, whereby the volume of dye administered to each cadaveric specimen depended on the response of the previous one. In case of failure, the next one received a higher volume (defined as the previous volume with an increment of 2.5 mL). If the previous cadaveric specimen had a successful block, the next one was randomized to a lower volume (defined as the previous volume with a decrement of 2.5 mL), with a probability of b=0.11, or the same volume, with a probability of 1–b=0.89. Success was defined as the staining of the femoral, lateral femoral cutaneous, and obturator nerves on dissection.ResultsThirty-six cadavers (60 cadaveric specimens) were included in the study. Using isotonic regression and bootstrap CI, the MEV90 for ultrasound-guided SIFIB was estimated to be 62.5 mL (95% CI 60 to 65).ConclusionFor ultrasound-guided SIFIB, the MEV90 of dye required to stain the femoral, lateral femoral cutaneous and obturator nerves is 62.5 mL. Further studies are required to correlate this finding with the MEV90 of local anesthetic in human subjects.

scholarly journals Intraneural Ultrasound-guided Sciatic Nerve Block

2018 ◽  
Vol 129 (2) ◽  
pp. 241-248 ◽  
Author(s):  
Gianluca Cappelleri ◽  
Andrea Luigi Ambrosoli ◽  
Marco Gemma ◽  
Valeria Libera Eva Cedrati ◽  
Federico Bizzarri ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Nerve Block ◽  
Local Anesthetic ◽  
Sciatic Nerve Block ◽  
Effective Volume ◽  
Ultrasound Guided ◽  
Biased Coin Design ◽  
Patient Reported ◽  
Sensory Motor

Abstract What We Already Know about This Topic What This Article Tells Us That Is New Background Both extra- and intraneural sciatic injection resulted in significant axonal nerve damage. This study aimed to establish the minimum effective volume of intraneural ropivacaine 1% for complete sensory-motor sciatic nerve block in 90% of patients, and related electrophysiologic variations. Methods Forty-seven consecutive American Society of Anesthesiologists physical status I-II patients received an ultrasound-guided popliteal intraneural nerve block following the up-and-down biased coin design. The starting volume was 15 ml. Baseline, 5-week, and 6-month electrophysiologic tests were performed. Amplitude, latency, and velocity were evaluated. A follow-up telephone call at 6 months was also performed. Results The minimum effective volume of ropivacaine 1% in 90% of patients for complete sensory-motor sciatic nerve block resulted in 6.6 ml (95% CI, 6.4 to 6.7) with an onset time of 19 ± 12 min. Success rate was 98%. Baseline amplitude of action potential (mV) at ankle, fibula, malleolus, and popliteus were 8.4 ± 2.3, 7.1 ± 2.0, 15.4 ± 6.5, and 11.7 ± 5.1 respectively. They were significantly reduced at the fifth week (4.3 ± 2.1, 3.5 ± 1.8, 6.9 ± 3.7, and 5.2 ± 3.0) and at the sixth month (5.9 ± 2.3, 5.1 ± 2.1, 10.3 ± 4.0, and 7.5 ± 2.7) (P < 0.001 in all cases). Latency and velocity did not change from the baseline. No patient reported neurologic symptoms at 6-month follow-up. Conclusions The intraneural ultrasound-guided popliteal local anesthetic injection significantly reduces the local anesthetic dose to achieve an effective sensory-motor block, decreasing the risk of systemic toxicity. Persistent electrophysiologic changes suggest possible axonal damage that will require further investigation.

scholarly journals The minimum effective concentration (MEC90) of ropivacaine for ultrasound-guided caudal block in anorectal surgery. A dose finding study

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257283
Author(s):  
Xuehan Li ◽  
Jun Li ◽  
Pei Zhang ◽  
Huifei Deng ◽  
Mingan Yang ◽  
...  
Keyword(s):  
Effective Concentration ◽  
Dose Finding ◽  
Anorectal Surgery ◽  
Sensory Blockade ◽  
Minimum Effective Concentration ◽  
Female Patients ◽  
Biased Coin Design ◽  
Finding Study ◽  
Dose Finding Study ◽  
Biased Coin

Background Caudal epidural block (CEB) provides reliable anesthesia for adults undergoing anorectal surgery. Despite the widely utilization, the minimum effective concentration for 90% patients (MEC90) of ropivacaine for CEB remains unknown. Objective To estimate MEC of ropivacaine for CEB in anorectal surgery. Design A prospective dose-finding study using biased coin design up-and-down sequential method. Setting Operating room and postoperative recovery area of Chengdu Shangjin Nanfu Hospital, from October 2019 to January 2020. Patients 50 males and 51 females scheduled for anorectal surgery. Interventions We conducted two independent biased coin design up-and down trials by genders. The concentration of ropivacaine administered to the first patient of male and female were 0.25% with fixed volume of 14ml for male and 12ml for female patients based on our previous study. In case of failure, the concentration was increased by 0.05% in the next subject. Otherwise, the next subject was randomized to a concentration 0.05% less with a probability of 0.11, or the same concentration with a probability of 0.89. Success was defined as complete sensory blockade of perineal area 15 min after the block evidenced by the presence of a lax anal sphincter and pain-free surgery. Main outcome measures The MEC of ropivacaine to achieve a successful CEB in 90%(MEC90) of the patients. Results The MEC90 of ropivacaine for CEB were estimated to be 0.35% (95% CI 0.29 to 0.4%) for male and 0.353% (95%CI 0.22 to 0.4%) for female. By extrapolation to MEC in 99% of subjects (MEC99) and pooled adjacent violators algorithm (PAVA) adjusted responses, it would be optimal to choose 0.4% ropivacaine with a volume of 14ml for male and 12ml for female. Conclusions A concentration of 0.35% ropivacaine with a volume of 14ml provided a successful CEB in 90% of the male patients, while 0.353% ropivacaine with a volume of 12ml provided a successful CEB in 90% of the female patients. A concentration of 0.4% and a volume of 14ml for male and 12 ml for female would be successful in 99% of the patients. Trial registration Chictr.org.cn identifier: No. ChiCTR 1900024315.

Cadaveric study investigating the phrenic-sparing volume for anterior suprascapular nerve block

2021 ◽  
pp. rapm-2021-102803
Author(s):  
Naraporn Maikong ◽  
Perada Kantakam ◽  
Apichat Sinthubua ◽  
Pasuk Mahakkanukrauh ◽  
De Q Tran ◽  
...  
Keyword(s):  
Nerve Block ◽  
Phrenic Nerve ◽  
Suprascapular Nerve ◽  
Cadaveric Study ◽  
Cadaveric Specimen ◽  
Biased Coin Design ◽  
Suprascapular Nerve Block ◽  
Lower Volume ◽  
Omohyoid Muscle ◽  
Previous Volume

BackgroundThis cadaveric study investigated the maximum effective volume of dye in 90% of cases (MEV90), required to stain the suprascapular nerve while sparing the phrenic nerve during the performance of an anterior suprascapular nerve block.MethodsIn cadaveric neck specimens, using ultrasound guidance, the block needle was advanced until its tip was positioned underneath the omohyoid muscle next to the suprascapular nerve. The dye was injected in order to achieve circumferential spread around the latter. Successful phrenic-sparing suprascapular nerve block was defined as the non-staining of the phrenic nerve on dissection. Volume assignment was carried out using a Biased Coin Design, whereby the volume of dye administered to each cadaveric specimen depended on the response of the previous one. In case of failure (ie, stained phrenic nerve), the next one received a lower volume (defined as the previous volume with a decrement of 2 mL). If the previous cadaveric specimen had a successful block (ie, non-stained phrenic nerve), the next one was randomized to a higher volume (defined as the previous volume with an increment of 2 mL), with a probability of b=0.11, or the same volume, with a probability of 1 – b=0.89.ResultsThirty-one cadavers (56 cadaveric neck specimens) were included in the study. Using isotonic regression and bootstrap CI, the MEV90 for phrenic-sparing anterior suprascapular nerve block was estimated to be 4.2 mL (95% CI 3.0 to 5.0 mL). The probability of a successful response was estimated to be 0.90 (95% CI 0.84 to 0.96).ConclusionFor ultrasound-guided anterior suprascapular nerve block, the MEV90 of dye required to spare the phrenic nerve is 4.2 mL. Further studies are required to correlate this finding with the MEV90 of local anesthetic in live subjects.

scholarly journals Median Effective Volume of 0.5% Ropivacaine for Ultrasound-guided Costoclavicular Block

2021 ◽  
Vol 134 (4) ◽  
pp. 617-625
Author(s):  
Anu Kewlani ◽  
Nidhi Bhatia ◽  
Jeetinder Kaur Makkar ◽  
Vishal Kumar
Keyword(s):  
Effective Dose ◽  
Local Anesthetic ◽  
Dose Finding ◽  
Ultrasound Guided ◽  
Finding Study ◽  
Minimum Score ◽  
Calculated Dose ◽  
Sequential Allocation ◽  
American Society ◽  
American Society Of Anesthesiologists

Background The median effective dose of ropivacaine required for producing an effective costoclavicular block has not yet been determined. The authors conducted this dose-finding study with the objective of determining the median effective dose of 0.5% ropivacaine required to produce a successful costoclavicular block for surgical anesthesia in 50% of the patients (ED50) as well as the calculated dose required for effective blockade in 95% of the patients (ED95). Methods This single-armed prospective study was conducted on 40 American Society of Anesthesiologists physical status I or II patients, aged 18 to 60 yr, with a body mass index of 18 to 30 kg/m2, scheduled to undergo forearm and hand surgeries under ultrasound-guided costoclavicular block. A volume of 0.5% ropivacaine administered in the costoclavicular space was determined using the sample up-and-down sequential allocation study design of binary response variables. The first patient received a volume of 26 ml of 0.5% ropivacaine. After a successful or unsuccessful block, the volume of local anesthetic was decreased or increased, respectively, by 2 ml in the next patient. Evaluation of sensory and motor block was performed every 5 min for 30 min and graded using a 3-point scale. Surgical anesthesia was considered to be successful if a minimum score of 14 was achieved and the surgeon was able to proceed with surgery without needing to supplement anesthesia. Results The volume of local anesthetic administered ranged from 8 to 26 ml. Centered isotonic regression with a bias-corrected Morris 95% CI derived by bootstrapping showed ED50 of 13.5 ml (95% CI, 11.5 to 15.4 ml) and ED95 of 18.9 ml (95% CI, 17.9 to 27.5 ml). Conclusions A 19-ml dose of 0.5% ropivacaine is likely to produce an effective ultrasound-guided costoclavicular block for providing adequate surgical anesthesia to 95% of the patients. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

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