Double Injection Techniques Research Articles

Comparative Study between Single, Double and Intra-Cluster Injection in Ultrasound-Guided Supraclavicular Brachial Plexus Block: A Randomized Trial

AbstractBackground: There are many different approaches for ultrasound-guided supraclavicular brachial plexus block. Each approach has a different success rate and complications.Aim of Study: The aim of this study is to compare intra-cluster injection technique compared with the most common supraclavicular approach single and double injection tech-niques.Material and Methods: Thirty-six patients received supr-aclavicular block were divided in to three groups. The total volume of local Anesthetic was 30ml 0.5% bupivacaine, In Gs (n=12) the whole volume was injected at corner pocket, while in Gd (n=12), half the volume of local anesthetic was injected at corner pocket and the other half was injected supero-lateral to subclavian artery. In Gic (n=12) the whole volume was injected inside main and satellite neural cluster. the onset time was recorded as the primary outcome.Results: Gic showed rapid onset compared to Gs and Gd (8.17±1.64 minutes, 18±2.45 minutes, 12.58±1.83 minutes, p<0.001) respectively. While Gd showed the longest duration than Gic and Gs (444.17±64.73 minutes, 310±50.09 minutes, 125.83±43.32 minutes, p<0.001) respectively. Time of first rescue analgesia was longer in Gd relative to Gic and G s (455±65.68 minute, 337.50±49.38 minutes, 136.67±49.10 minutes, p<0.001). Complication was noticed in only one patient in Gd.Conclusion: Intra-cluster technique for Supra-Clavicular Brachial Plexus Block showed rapid onset with adequate post-operative analgesia and minimal complications.

Numerical study on double injection techniques in a gasoline and biodiesel fueled RCCI (reactivity controlled compression ignition) engine

In an RCCI (reactivity controlled compression ignition) engine, the double injection strategy is a technical tool to control its combustion process. In this study, the effects of two key injection parameters, namely dwell and split fraction, are numerically investigated in a gasoline and biodiesel fueled RCCI engine. In the engine, gasoline is used as the premixed fuel; meanwhile, biodiesel is directly injected into the air-fuel mixture. The coupled KIVA4-CHEMKIN code was used to simulate the in-cylinder combustion process and the emissions formation. The gasoline/biodiesel reaction mechanism, which consists of 107 species and 425 reactions, was implemented in the code for detailed chemistry calculation. During the simulation, the dwells between 1st and 2nd SOI (start of injection) timings were varied at 5, 15, 25 and 35°CA, while the 1st SOI timing was fixed at −35 °C ATDC. Besides, the 1st pulse fractions were changed at 30%, 50% and 70%; accordingly, the rest of the biodiesel was injected through the 2nd pulse. The combustion characteristics (including in-cylinder pressure, HRR (heat release rate), ignition delay, PPRR (peak pressure rise rate) and combustion duration), engine performance and emissions (NO and soot) formations were compared under various operating conditions. The results show that double injection strategy results in longer ignition delay. In contrast with the dwells of 15° and 25°CA, the cases with dwells of 5° and 35°CA could result in acceptable PPRR, longer combustion duration, but slightly lower IMEP (indicated mean effective pressure). However, short dwell of 5°CA displays better results on NO and soot emissions. The combustion process with long dwell of 35°CA is both reactivity and mixing controlled.

Single, double or multiple-injection techniques for non-ultrasound guided axillary brachial plexus block in adults undergoing surgery of the lower arm.

Regional anaesthesia comprising axillary block of the brachial plexus is a common anaesthetic technique for distal upper limb surgery. This is an update of a review first published in 2006 and previously updated in 2011 and 2013. To compare the relative effects (benefits and harms) of three injection techniques (single, double and multiple) of axillary block of the brachial plexus for distal upper extremity surgery. We considered these effects primarily in terms of anaesthetic effectiveness; the complication rate (neurological and vascular); and pain and discomfort caused by performance of the block. We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 3), MEDLINE (1946 to April Week 1 2016), Embase (1947 to April 18 2016) and reference lists of trials. We contacted trial authors. The date of the last search was April 2016 (updated from March 2013). We included randomized controlled trials that compared double with single-injection techniques, multiple with single-injection techniques, or multiple with double-injection techniques for axillary block in adults undergoing surgery of the distal upper limb. We excluded trials using ultrasound-guided techniques. Independent study selection, 'Risk of bias' assessment and data extraction were performed by at least two investigators. We undertook meta-analysis. We included one new trial involving 45 participants in this updated review. In total we included 22 trials involving a total of 2193 participants who received regional anaesthesia for hand, wrist, forearm or elbow surgery. 'Risk of bias' assessment indicated that trial design and conduct were generally adequate; the most common areas of weakness were in blinding and allocation concealment.Nine trials comparing double versus single injections showed a statistically significant decrease in primary anaesthesia failure (risk ratio (RR) 0.55, 95% confidence interval (CI) 0.34 to 0.89, high-quality evidence). Subgroup analysis by method of nerve location showed that the effect size was greater when neurostimulation was used rather than the transarterial technique.Nine trials comparing multiple with single injections showed a statistically significant decrease in primary anaesthesia failure (RR 0.25, 95% CI 0.14 to 0.42, high-quality evidence). Pooled data from five trials also showed a significant decrease in incomplete motor block (RR 0.61, 95% CI 0.39 to 0.96, high-quality evidence) in the multiple-injection group.Twelve trials comparing multiple versus double injections showed a statistically significant decrease in primary anaesthesia failure (RR 0.27, 95% CI 0.19 to 0.39, high-quality evidence). Pooled data from six trials also showed a significant decrease in incomplete motor block (RR 0.55, 95% CI 0.36 to 0.85, high-quality evidence) in the multiple injection group.Tourniquet pain was significantly reduced with multiple injections compared with double injections (RR 0.53, 95% CI 0.33 to 0.84, high-quality evidence). Otherwise there were no statistically significant differences between groups in any of the three comparisons on secondary analgesia failure, complications and patient discomfort. Compared with multiple injections, the time for block performance was significantly shorter for single injection (MD 3.33 minutes, 95% CI 2.76 to 3.90) and double injections (MD 1.54 minutes, 95% CI 0.80 to 2.29); however there was no difference in time to readiness for surgery. This review provides evidence that multiple-injection techniques using nerve stimulation for axillary plexus block produce more effective anaesthesia than either double or single-injection techniques. However, there was insufficient evidence to draw any definitive conclusions regarding differences in other outcomes, including safety.

Enhanced performance using an SU-8 dielectric interlayer in a bulk heterojunction organic solar cell.

The effect of inserting an SU-8 dielectric interlayer into inverted bulk heterojunction (BHJ) organic solar cells (OSCs) was studied. Insertion of an ultrathin layer of SU-8 between the zinc oxide (ZnO) electron transport layer and the photoactive layer resulted in a smoother interface and a 14% enhancement in power conversion efficiency. The properties of devices with and without an SU-8 interlayer were investigated using transient photovoltage (TPV) and double injection (DoI) techniques, and it was found that devices with SU-8 show longer carrier lifetimes and greater mobility-lifetime (μ-τ) products than those without. Devices with SU-8 were also found to have improved stability. The results indicate that the insertion of an SU-8 interlayer reduces the recombination rate for photogenerated carriers without affecting the charge transport properties, improving overall performance and stability.

Transconjunctival approach to peribulbar block

As increasing numbers of anesthetists perform eye block anesthesia, thorough understandings of peribulbar injection techniques are important for safe practice. There is uncertainty in the literature regarding the optimum needle length, entry point, volume of injectate, and use of single vs double-injection techniques. A modified technique of peribulbar block anesthesia is presented, which offers increased safety, simplicity, low cost, and little change to instrumentation.

Is the Double-Injection Technique Really Needed?

To the Editor: The recent article by March et al. (1) comparing single and double injection techniques of the sciatic nerve at the popliteal level raises several issues. First, the puncture point is not clearly defined and the time between the two injections in the two stimulation groups is not given. Second, stimulation of the two branches of the sciatic nerve at the popliteal level using a posterior approach and a fixed defined point, (10 cm from the popliteal skin crease) does not take into consideration the anatomical variation between patients. It has been shown in 500 consecutive patients scheduled for a popliteal block, that the distance between the knee crease to the apex of the popliteal fossa—the apex being the ideal puncture point for performing this block because it is the most proximal point from the knee crease (which allows a puncture without interfering with the muscle structure), varies from 6 to 13 cm (2). Third, when the two parts of the sciatic nerve (peroneal and tibial) are still together, the procedure used by the authors is not without risk. In other words, if the second stimulation occurs on a nerve, that is already partially anesthetized, the risk of inadvertent intraneural injection is increased. Finally, we disagree with the author's conclusion, because one stimulation at the apex of the popliteal fossa which elicits inversion (almost) always successfully blocks both components of the sciatic nerve (2). A double stimulation may be indicated, only when inversion is, for any reason, impossible to elicit, meaning that the peroneal and tibial parts of the sciatic nerve are already well separated (3). Markus Risch, MD Stephan Blumenthal, MD Alain Borgeat, MD Department of Anesthesia Balgrist University Hospital Zurich, Switzerland [email protected]

Lateral or Posterior Popliteal Approach for Sciatic Nerve Block: Difference is Related to the Anatomy

To the Editor: March and colleagues (1) comparing single- and double-injection techniques for blockade of the sciatic nerve block via a posterior popliteal approach, concluded that double-nerve stimulation resulted in similar onset time and overall success rate when compared with that after single-nerve stimulation. In the double-injection group, they located both common peroneal and tibial nerve, whereas in the single-injection group they preferentially elicited foot inversion, interpreting this motor response to reflect needle proximity to both sciatic nerve trunks (2). Our group has extensive experience providing regional anesthesia for outpatients undergoing foot surgery (3). We recently showed that, when using a lateral popliteal sciatic nerve block, a single injection targeting the tibial nerve is more effective than a single injection targeting the peroneal nerve and is also as effective as a double injection of both branches of the sciatic nerve (4). We believe that results from March's work lend further support for our results, even when the different drugs and dosages used are taken into account. When a double-injection procedure is employed, the success rates after the lateral or posterior approaches are similar (respectively, 94% vs 87%) whereas a single-injection technique yields similar or even better results only if it is performed via a lateral approach and it is targeted at the tibial branch of the sciatic nerve (success rate: lateral 94% vs posterior 77%). Considering the anatomy of the sciatic nerve at the popliteal level (5), targeting the tibial nerve via a lateral popliteal approach will likely result in injecting local anesthetic within the adventitia that envelops both branches of the sciatic nerve (4). On the other hand, the same single injection technique performed via a posterior approach will not assure that local anesthetic is injected within the tibial and peroneal common perineural space. Stefano Palmisani Department of Anesthesiology and Intensive Care Medicine Sant'Andrea Hospital University of Rome La Sapienza [email protected] Paolo Ronconi, MD Foot Medical Hospital Roberto Alberto De Blasi, MD Roberto Arcioni, MD Department of Anesthesiology and Intensive Care Medicine Sant'Andrea Hospital University of Rome La Sapienza Rome, Italy

Lateral popliteal sciatic nerve block: a single injection targeting the tibial branch of the sciatic nerve is as effective as a double‐injection technique

Evidence indicating that single- and double-injection techniques for inducing a sciatic nerve block via a posterior subgluteal approach yield a similar success rate prompted us to investigate whether the two anesthetic techniques yield a similar success rate via a lateral approach. We also hypothesized that, owing to the peculiar anatomic features of the sciatic nerve at the popliteal level, a single injection via the lateral approach might induce effective anesthesia by targeting the tibial nerve only. Ninety-six patients undergoing popliteal sciatic nerve block via a lateral popliteal approach for foot surgery were randomized to receive a single 30-ml injection of ropivacaine 7.5 mg/ml to block the tibial nerve (TN group, n= 32) or the common peroneal nerve (CPN group, n= 32), or two separate 15-ml injections (TN + CPN group, n= 32), after stimulation to evoke motor responses from the target nerves. The mean time to obtain a complete sensory blockade (surgical anesthesia) was shorter in the TN group than in the CPN and TN + CPN groups (14 +/- 7 min vs. 23 +/- 17 and 21 +/- 14 min, respectively; P < 0.05). The success rate was similar in the TN and TN + CPN groups (94%) and, 25 min after the initial injection, was already better in these groups than in the CPN group (94% vs. 75%; P < 0.05). A lateral popliteal sciatic nerve block obtained with a single 30-ml injection of ropivacaine 7.5 mg/ml after electrostimulation to locate the tibial nerve is as effective as multiple TN + CPN stimulation and injection, and local anesthesia has a significantly shorter onset time.

Single, Double, or Multiple Injection Techniques for Axillary Brachial Plexus Block for Hand, Wrist, or Forearm Surgery

BACKGROUND: Regional anesthesia comprising axillary block of the brachial plexus is a common anesthetic technique for distal upper extremity surgery. OBJECTIVES: To compare the relative effects of anesthetic techniques using either single, double, or multiple injections for axillary block of the brachial plexus for distal upper extremity surgery. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, as well as reference lists of trials. We contacted trial authors and the medical industry. Date of last search: August 2004. SELECTION CRITERIA: We included randomized controlled trials that compared double with single injection techniques, multiple with single injection techniques, or multiple with double injection techniques for axillary block in adults undergoing surgery of the distal upper extremity. DATA COLLECTION AND ANALYSIS: We performed independent study selection, quality assessment, and data extraction. We undertook meta-analysis, including exploratory analyses according to the method of nerve location and definition of primary anesthesia failure. MAIN RESULTS: The 12 included trials involved a total of 981 participants who received regional anesthesia for hand, wrist, forearm, or elbow surgery. Trial design and conduct was generally adequate, although several trials failed to monitor longer-term effects and to provide sufficient description of their study populations. Substantial heterogeneity precluded the pooling of data for primary anesthesia failure from the five trials comparing double versus single injections. However, double injections were significantly more effective than single injections in the three trials where electrolocation was used throughout (relative risk (RR) 0.31, 95% confidence interval (CI) 0.31 to 0.74). Five trials compared multiple with single injections. These showed a statistically significant decrease in primary anesthesia failure (RR 0.24, 95% CI 0.13 to 0.46) and incomplete motor block (RR 0.61, 95% CI 0.39 to 0.96) in the multiple injection group. Six trials compared multiple with double injections. These showed a statistically significant decrease in primary anesthesia failure (RR 0.23, 95% CI 0.14 to 0.38) and incomplete motor block (RR 0.55, 95% CI 0.36 to 0.85) in the multiple injection group. Generally, none of the differences between the two groups of any of the three comparisons in secondary analgesia failure, complications, and patient discomfort were statistically significant. The time for block performance was significantly shorter for single and double injections compared with multiple injections, but the requirement for supplementary blocks in these groups tended to increase the time to readiness for surgery. REVIEWERS’ CONCLUSIONS: This review provided some evidence that multiple injection techniques using nerve stimulation for axillary plexus block provide more effective anesthesia than either double or single injection techniques. However, there was insufficient evidence for other outcomes, including safety. CITATION: Handoll HHG, Koscielniak-Nielsen ZJ. Single, double or multiple injection techniques for axillary brachial plexus block for hand, wrist or forearm surgery (Cochrane Review). In: The Cochrane Library, Issue 1, 2006. Chichester, UK: John Wiley & Sons, Ltd. Reprinted with permission.

A comparison of two double‐injection techniques for peribulbar block analgesia: infero‐temporal plus supero‐medial vs. infero‐temporal plus medial‐percaruncular*

Combinations of infero-temporal and either supero-nasal ('inferior-superior') or medial percaruncular ('inferior-medial') injections are popular double-injection techniques for establishing peribulbar block analgesia. This study compared the efficacy of these two techniques in achieving ocular and lid akinesia. One hundred patients were randomized to receive inferior-superior or inferior-medial injections in a study in which injectate, injectate volumes, 5-min ocular akinesia scoring (0-8), lid scoring (0-2) and supplemental injection protocols were standardized. The numbers of supplemental injections required at each observation period and the total volume of injectate required to produce ocular and lid akinesia were compared. The two test groups were demographically similar. The inferior-medial combination achieved greater ocular akinesia than the inferior-superior combination 5 min after the initial injections (mean score +/- standard deviation of 1.74 +/- 1.86 vs. 2.66 +/- 2.39; P < 0.05), with a reduced requirement for supplementary injections (3 vs. 23 supplementary injections; P < 0.025). The inferior-superior technique achieved greater lid akinesia at 5 min than the inferior-medial technique (mean score +/- standard deviation of 0.7 +/- 0.9 vs. 0.3 +/- 0.58; P < 0.005). A medial subconjunctival hemorrhage occurred in one patient in the inferior-medial group. Compared with the inferior-superior technique, the inferior-medial combination achieved more rapid ocular akinesia with less need for supplementation, but induced less efficient lid akinesia and had a propensity to cause iatrogenic subconjunctival hemorrhage. The latter complication is considered by our surgeons to be a contraindication to the inferior-medial technique in patients undergoing trabeculectomy.

A radio-on-hybrid WDM transport system

A radio-on-hybrid wavelength-division-multiplexing (WDM) transport system based on distributed feedback laser diodes and semiconductor optical amplifiers with double external light injection techniques is proposed and demonstrated. Good performances of bit-error rate, modulation-error ratio, carrier-to-noise ratio, error vector magnitude, and third-order intermodulation distortion-to-carrier ratio were achieved in our proposed systems. This demonstrated that such a radio-on-hybrid WDM transport system is attractive for 256-quadrature amplitude modulation/gigabit Ethernet, 2.4-GHz/local area network, and 5.8-GHz/intelligence transport system signals.

Employing double external light injection techniques to improve radio-on-DWDM system performance

A radio-on-dense-wavelength-division-multiplexing (DWDM) transport system employing double external light injection techniques to improve the systems' overall performance is proposed and demonstrated. Simultaneously using the external light injection technique to enhance the bandwidth of the vertical-cavity surface-emitting laser and increase the saturation output power of the semiconductor optical amplifier, resulting in a system with better transmission performance.

Employing double external light injection techniques to improve radio-on-fiber systems performance

A radio-on-fiber (ROF) transport system employing double external light injection techniques to improve systems’ performance is proposed and demonstrated for the first time. Simultaneously using external light injection techniques to increase the frequency response of the laser diode and the saturation output power of the semiconductor optical amplifier (SOA), leading to decrease third order intermodulation distortion (IMD 3) and SOA gain-saturation-induced distortion. Such a proposed ROF transport system is suitable for the long-haul microwave optical links.

Comparison of the Parasacral Approach and the Posterior Approach, with Single- and Double-Injection Techniques, to Block the Sciatic Nerve

The purpose of this study was to compare parasacral and Winnie's single- or double-injection approaches for sciatic nerve block. One hundred fifty adults scheduled to undergo lower limb surgery were randomized to receive on the sciatic nerve 20 ml ropivacaine, 0.75%: single bolus for parasacral and Winnie's single injection. For Winnie's double injection, the peroneal and tibial nerves received separately 10 ml plus 10 ml. Blocks were performed with the use of nerve stimulator (intensity < 0.5 mA, 1 Hz). For the parasacral method, a line was drawn between the posterior superior iliac spine and the ischial tuberosity; needle entry was at 6 cm inferior to the posterior superior iliac spine. The groups were similar. Time to perform the block was 2 (1-5) min for the parasacral method, with no difference from Winnie's single injection (3 [1-10] min), but was shorter with double injection (5.5 [2-15] min) (P = 0.0001). Onset of sensory block was similar in the parasacral (25 [7.5-50] min) and Winnie single-injection groups (25 [5-50] min) but significantly longer in the double-injection group (15 [5-50] min). Success rates for complete block were similar in the parasacral (66%) and Winnie's double-injection groups (68%) after 30 min but higher in the Winnie's single-injection group for tibial sensory and motor block (48%) (P < 0.017). Time to perform a parasacral block was short, and the parasacral approach had a high success rate and a short onset time. Therefore, this block might be a useful alternative to Winnie's modification for sciatic nerve block.

Novel flow-injection analysis method for bioprocess monitoring

A technique for process analysis was developed based on flow-injection analysis (FIA) combined with diode-array spectrophotometry. The method demonstrates the advantages of coupling single-line FIA with diode-array detection, utilizing the stopped-flow and double injection techniques with a dual-wavelength monitoring approach. A simple, robust FIA hardware system was designed and rigorously tested for on-line process application. A fed-batch fermentation served as the test bed for the development of this system, monitoring selected analytes of interest, viz., glucose, ammonium ion and total protein.

On proliferation metabolism of the rat liver following partial hepatectomy. Autoradiographic studies with H3-cytidine, phenylalanine and thymidine

During the first wave of parenchymal liver regeneration in adult rats after partial hepatectomy, the cellular synthesis and migration of RNA and the metabolism of protein were studied by autoradiography following an injection of3H-cytidine or3H-l-phenylalanine and double injections of 1 of these precursors +3H-thymidine. The following results were obtained: the synthesis and migration of RNA and the metabolism of protein are enhanced under these conditions of proliferation. In spite of this, the relation of metabolic activity in nucleolus, karyoplasm and cytoplasm remains constant. By double injection techniques it is proved that no differences exist in migration of RNA into the cytoplasm and cytoplasmic protein synthesis between cells with or without DNA synthesizing nuclei.