http://www.nysora.com/files/suggest-articles-pdfs/LAST-and-US-Barrington-RAPM.pdf

Ultrasound Guidance Reduces the Risk of Local Anesthetic Systemic Toxicity Following Peripheral Nerve Blockade

https://rapm.bmj.com/content/rapm/34/2/134-170.full.pdf

Lower extremity regional anesthesia: essentials of our current understanding.

https://rapm.bmj.com/content/rapm/35/Suppl_1/S1.full.pdf

The ASRA evidence-based medicine assessment of ultrasound-guided regional anesthesia and pain medicine: Executive summary.

BACKGROUND: Ultrasound guidance facilitates precise needle and injectate placement, increasing axillary block success rates, reducing onset times, and permitting local anesthetic dose reduction. The minimum effective volume of local anesthetic in ultrasound-guided axillary brachial plexus block is unknown. The authors performed a study to estimate the minimum effective anesthetic volume of 2% lidocaine with 1:200,000 epinephrine (2% LidoEpi) in ultrasound-guided axillary brachial plexus block.

METHODS: After ethical approval and informed consent, patients undergoing hand surgery of less than 90 min duration were recruited. A step-up/step-down study model was used with nonprobability sequential dosing based on the outcome of the previous patient. The starting dose of 2% LidoEpi was 4 ml per nerve. Block failure resulted in a dose increase of 0.5 ml; block success in a reduction of 0.5 ml.A blinded assistant assessed sensory and motor blockade at 5-min intervals up to 30 min. Block performance time and duration were measured. Two predetermined stopping points were used; a minimum of five consecutive block success/failures and five consecutive successful blocks at 1 ml per nerve.

RESULTS: The study was terminated when five consecutive patients had successful blocks using 1 ml of 2% LidoEpi per nerve (overall group n = 11). All five patients had surgical anesthesia within 10 min. The mean (SD) block performance time was 445 (100) s, and block duration was 190 min (range 120-310 min). All surgical procedures were performed under regional anesthesia with anxiolytic sedation provided in 3 of 11 cases.

CONCLUSION: Successful ultrasound-guided axillary brachial plexus block may be performed with 1 ml per nerve of 2% LidoEpi.

An estimation of the minimum effective anesthetic volume of 2% lidocaine in ultrasound-guided axillary brachial plexus block.

Background: Use of ultrasound by anaesthesiologists performing regional blocks is rapidly gaining popularity. The aims of this review were to summarize and update accumulating evidence on ultrasound-guided nerve blocks, with an emphasis on the clinical relevance of the results and to critically appraise changing standards in regional anaesthesia.



Methods: A search of MEDLINE and EMBASE (1966 to 31 December 2007) was conducted using the following free terms: ‘ultrasound and regional anesthesia’, ‘ultrasound and peripheral block’ and ‘ultrasound and nerve and block’. These were combined with the MESH terms ‘nerve block’ and ‘ultrasonography’. The following limits were applied: studies with abstracts, only in humans, published in core clinical journals. Trial type: meta-analysis, randomized-controlled trial and clinical trial.



Results: When peripheral nerves are adequately imaged by ultrasound, the concomitant use of nerve stimulation offers no further advantage. However, several studies reported problems with obtaining satisfactory images in some patients. Ultrasound guidance significantly shortened the block performance time and/or reduced the number of needle passes to reach the target in all comparative studies. The occurrence of paraesthesia during block performance was also reduced, but not the incidence of short-lasting post-operative neuropraxia. The frequency of accidental vascular punctures may be lower, but the data are contradictory. Block onset time was significantly shortened. Block duration was longer in children, but not in adults. Ultrasound also allowed dose reduction of the local anaesthetic (LA).



Conclusions: Ultrasound guidance shortens the block performance time, reduces the number of needle passes and shortens the block onset time. Blocks may be performed using lower LA doses.

Ultrasound-guided peripheral nerve blocks : What are the benefits?

Background We tested the hypothesis that ultrasound guidance may reduce the minimum effective anaesthetic volume (MEAV50) of ropivacaine 0.5% required to block the femoral nerve compared with nerve stimulation guidance. Methods After standard premedication and sciatic nerve block were given, 60 patients undergoing knee arthroscopy were randomly allocated to receive a femoral nerve block with ropivacaine 0.5% using either nerve stimulation (group NS, n = 30) or ultrasound (group US, n = 30) guidance. The volume of the injected solution was varied for consecutive patients based on an up-and-down staircase method according to the response of the previous patient. The initial volume was 12 ml. A double-blinded observer evaluated the occurrence of complete loss of pinprick sensation in the femoral nerve distribution, with concomitant block of the quadriceps muscle: positive or negative responses within 30 min after the injection determined a 3 ml decrease or increase for the next patient, respectively. Results The mean ( sd ) MEAV50 for femoral nerve block was 15 (4) ml (95% CI, 7–23 ml) in group US and 26 (4) ml (95% CI, 19–33 ml) in group NS (P = 0.002). The effective dose in 95% of cases (ED95) calculated with probit transformation and logistic regression analysis was 22 ml (95% CI, 13–36 ml) in group US, and 41 ml (95% CI, fs 24–66 ml) in group NS. Conclusions Ultrasound guidance provided a 42% reduction in the MEAV of ropivacaine 0.5% required to block the femoral nerve as compared with the nerve stimulation guidance.

Effects of ultrasound guidance on the minimum effective anaesthetic volume required to block the femoral nerve

PURPOSE
To evaluate the survival of implants and abutments and the incidence of mechanical complications of single posterior implant-supported restorations using prefabricated titanium abutments.


MATERIALS AND METHODS
This retrospective clinical study analyzed 172 Astra Tech OsseoSpeed internal hexagon implants (Dentsply Sirona) placed in 85 patients with a follow-up between January 2009 and January 2019. All implants were restored with prefabricated titanium abutments and cement-retained metal-ceramic crowns. The clinical outcomes recorded were implant and abutment survival rates and mechanical complications (abutment/implant fractures, screw loosening/fracture, decementation of the superstructure, veneer chipping/fractures) and were analyzed according to age, sex, implant length/diameter, bone graft, arch, implant position, parafunctional habit or dental status, and opposite arch. Kaplan-Meier survival analysis was used to determine whether the distribution of time to event/failure differed based on implant position (premolar or molar), implant diameter, or abutment angulation.


RESULTS
During the observation period (mean: 108 months), implant and abutment cumulative survival rates were 97.7% and 98.3%, respectively, with no statistically significant differences between implant positions (molar/premolar), implant diameters (3.5 vs 4 mm), or abutment angles (straight vs 15 degrees). Of the 172 single posterior implant-supported restorations, 14 mechanical complications (8.2%) were recorded. In particular, 3 abutment fractures (1.7%), 2 screw loosenings (1.2%), 2 screw fractures (1.2%), 1 implant fracture (0.6%), 2 chipping/fractures of veneering materials (1.2%), and 4 decementations of the superstructure (2.3%) occurred.


CONCLUSION
The single posterior implant-supported restorations using prefabricated titanium abutments remain a clinically acceptable treatment in terms of prosthetic procedure and cost-effectiveness.

Survival and Mechanical Complications of Posterior Single Implant-Supported Restorations Using Prefabricated Titanium Abutments: A Medium- and Long-Term Retrospective Analysis with up to 10 Years Follow-up.

G. De Marco

Papers

Effects of ultrasound guidance on the minimum effective anaesthetic volume required to block the femoral nerve

Survival and Mechanical Complications of Posterior Single Implant-Supported Restorations Using Prefabricated Titanium Abutments: A Medium- and Long-Term Retrospective Analysis with up to 10 Years Follow-up.