Jet-injection assisted photodynamic therapy for superficial and nodular basal cell carcinoma: A pilot study.

BACKGROUND: Photodynamic therapy (PDT) with topical δ-Aminolevulinic acid (ALA) has efficacy in treating basal cell carcinoma (BCC) but is limited by incomplete penetration of ALA into the deeper dermis. This prospective open-label pilot trial investigated the safety and efficacy of photosensitizer jet injection for PDT (JI-PDT) for BCC treatment. It was performed with 15 patients (n = 15) with histologically confirmed, untreated, low-risk nodular BCCs at a single institution. METHODS: For the intervention, JI-PDT patients (n = 11) received two sessions of jet-injected ALA with PDT separated by four to 6 weeks. To further understand treatment technique, another group of patients (n = 4) received jet-injected ALA followed by tumor excision and fluorescence microscopy (JI-E). Treatment tolerability was assessed by local skin responses (LSR) score at five distinct time intervals. Fluorescence microscopy assessed protoporphyrin IX penetration depth and biodistribution within the tumor. At the primary endpoint, tumor clearance was evaluated via visual inspection, dermoscopy and reflectance confocal microscopy. Postinjection and postillumination pain levels, and patient satisfaction, were scored on a 0-10 scale. RESULTS: Fifteen participants with mean age of 58.3, who were 15/15 White, non-Hispanic enrolled. The median composite LSR score immediately after JI-PDT was 5 (interquartile range [IQR] = 3) which decreased to 0.5 (IQR = 1) at primary endpoint (p < 0.01). Immunofluorescence of excised BCC tumors with jet-injected ALA showed photosensitizer penetration into papillary and reticular dermis. Of the 13 JI-PDT tumors, 11 had tumor clearance confirmed, 1 recurred, and 1 was lost to follow-up. 1/11 patients experienced a serious adverse event of cellulitis. 70% of patients had local scarring at 3 months. Patients reported an average pain level of 5.6 (standard deviation [SD] = 2.3) during jet injection and 3.7 (SD = 1.8) during light illumination. CONCLUSIONS: Jet injection of ALA for PDT treatment of nodular low-risk BCC is tolerable and feasible and may represent a novel modality to improve PDT.

Home-Use Hyaluronic Acid Jet Injectors: Unreliable and Unsafe.

BACKGROUND: Needle-free hyaluronic acid (HA) jet injectors are gaining popularity for rejuvenation treatment. The devices are widely available online and are used for self-injection or in beauty salons by nonphysicians. However, little is known about their performance and safety. OBJECTIVE: To explore the injection efficiency and cutaneous biodistribution patterns administered with home-use compared with medical jet injectors and to assess safety aspects. MATERIALS AND METHODS: The authors injected HA into ex vivo human skin with 4 home-use and 2 medical injectors. The intracutaneous dose of HA was calculated, and the cutaneous biodistribution of HA was assessed using a 3-dimensional Fluorescent Imaging Cryomicrotome System (3D-FICS). Safety aspects were evaluated based on the presence of a manual, CE (conformité européenne) mark, and sterility. RESULTS: The intracutaneous dose delivered by the home-use injectors was markedly lower compared with the medical injectors. 3D imaging for home-use injectors showed superficial epidermal distribution with low distribution volumes. For medical injectors, volumes were substantially larger and mainly middermal. All evaluated safety aspects were lacking. CONCLUSION: Results of this study suggest that the specific combinations of home-use injectors and HA used in this study are unreliable and unsafe, which casts doubts on the performance of these treatments in general.

Large volume subcutaneous delivery using multi-orifice jet injection.

Needle-free jet injection is an alternative drug delivery technique that uses the liquid drug itself to penetrate through the skin. This technology is not only a promising alternative to hypodermic needles but also has the potential to replace intravenous delivery with rapid, needle-free subcutaneous delivery for large-volume treatments. In this work we propose a parallelised, 'multi-orifice' approach to overcome the volume constraints of subcutaneous tissue. We present a prototype multi-orifice nozzle with up to seven orifices and use this nozzle to perform injections into samples of ex vivo porcine tissue. These injections demonstrated the rapid (<0.15 s) delivery of up to 2 mL into the tissue using both three and seven orifices. Delivery success (measured as the percentage of fluid deposited in the tissue relative to the total volume that left the device) was very similar when using three versus seven injection orifices. A computational fluid dynamic model of multi-orifice jet injection is also presented. This model predicts that jet production is largely unaffected as the spacing between orifices is changed from 3 mm to 48 mm. This finding is supported by measurements of the speed, volume, and shape of the jets produced by the prototype nozzle that showed very similar jets were produced through all seven orifices. These findings demonstrate the feasibility of multi-orifice jet injection for needle-free delivery of large volumes. This promising technique has the potential to improve patient experience and reduce healthcare costs in large volume parenteral delivery applications.

Experimental investigation of the optimal driving pressure for a larger-volume controllable jet injection system.

Jet injection technology has become the alternative drug delivery method of conventional needle-based injection due to its obvious advantages. In order to meet the demand for larger volume injection, the pneumatic jet injection systems have efficiently administrated vaccine up to 1 mL in human. Our recent study has also demonstrated that controlling the driving pressure enabled the pneumatic jet injection system to deliver larger volumes of drugs to target sites at desired rates and times. This work continues to explore the optimal two-phase driving pressure combination with better injection efficiency for typical larger-volume (1.0 mL) jet injection with controllable pneumatic jet injection system. Under the combination of a first phase driving pressure of 1.00 MPa and a second phase driving pressure ranging from 0.25 to 0.90 MPa, dynamic characteristics, dispersion characteristics and pharmacokinetic characteristics of this controllable jet injection system were quantitatively analyzed. In all experiments, it was confirmed that the optimal driving pressure combination of 1.0 mL ejection volume was close to (1.00-0.50) MPa. That is, the injection velocities of 151.85 m/s and 102.01 m/s for the first and second phase respectively facilitated better injection performance with a controlled release of 1.0 mL ejection volume. This strategy is practical for facilitating the clinical application of large-volume controllable jet injection systems.

A Promising Needle-Free Pyro-Drive Jet Injector for Augmentation of Immunity by Intradermal Injection as a Physical Adjuvant.

Current worldwide mRNA vaccination against SARS-CoV-2 by intramuscular injection using a needled syringe has greatly protected numerous people from COVID-19. An intramuscular injection is generally well tolerated, safer and easier to perform on a large scale, whereas the skin has the benefit of the presence of numerous immune cells, such as professional antigen-presenting dendritic cells. Therefore, intradermal injection is considered superior to intramuscular injection for the induction of protective immunity, but more proficiency is required for the injection. To improve these issues, several different types of more versatile jet injectors have been developed to deliver DNAs, proteins or drugs by high jet velocity through the skin without a needle. Among them, a new needle-free pyro-drive jet injector has a unique characteristic that utilizes gunpower as a mechanical driving force, in particular, bi-phasic pyrotechnics to provoke high jet velocity and consequently the wide dispersion of the injected DNA solution in the skin. A significant amount of evidence has revealed that it is highly effective as a vaccinating tool to induce potent protective cellular and humoral immunity against cancers and infectious diseases. This is presumably explained by the fact that shear stress generated by the high jet velocity facilitates the uptake of DNA in the cells and, consequently, its protein expression. The shear stress also possibly elicits danger signals which, together with the plasmid DNA, subsequently induces the activation of innate immunity including dendritic cell maturation, leading to the establishment of adaptive immunity. This review summarizes the recent advances in needle-free jet injectors to augment the cellular and humoral immunity by intradermal injection and the possible mechanism of action.

A one-time pneumatic jet-injection of 5-fluorouracil and triamcinolone acetonide for treatment of hypertrophic scars-A blinded randomized controlled trial.

BACKGROUND: Patients with hypertrophic scars (HTS) risk reduced quality of life due to itching, pain, poor cosmesis, and restriction of movement. Despite good clinical efficacy, patients are often reluctant to undergo repeated needle injections due to pain or needle phobia. OBJECTIVES: To evaluate the applicability of needle-free pneumatic jet injection (PJI) and assess changes in hypertrophic scars following a single PJI treatment with 5-fluorouracil (5-FU) and triamcinolone acetonide (TAC). METHODS: Twenty patients completed this blinded, randomized, controlled, split-scar trial. The intervention side of the HTS received a one-time treatment with PJIs containing a mixture of TAC + 5-FU injected at 5 mm intervals (mean 7 PJI per HTS); the control side received no treatment. Assessments were made at baseline and 4 weeks posttreatment. Outcome measures included change in (1) Vancouver Scar Scale (VSS) total score and subscores, (2) scar volume and surface area assessed by three-dimensional imaging, (3) skin microarchitecture measured by optical-coherence tomography (OCT), (4) photo-assessed scar cosmesis (0-100), (5) patient-reported pain and satisfaction (0-10), and (6) depiction of drug biodistribution after PJI. RESULTS: PJI with TAC + 5-FU significantly decreased both HTS height (-1 VSS; p = 0.01) and pliability (-1 VSS; p < 0.01) with a nonstatistically significant reduction of -1 in total VSS score (0 in control; p = 0.09). On 3D imaging, a 33% decrease in scar volume (p = 0.016) and a 37% decrease in surface area (p = 0.008) was observed. OCT indicated trends towards smoother scar surface (Ra 11.1-10.3; p = 0.61), normalized dermal microarchitecture (attenuation coefficient: 1.52-1.68; p = 0.44), and a reduction in blood flow between 9% and 17% (p = 0.50-0.79). Despite advances in VSS subscores and OCT, no improved photo-assessed cosmesis was found (-3.2 treatment vs. -1.4 control; p = 0.265). Patient-reported pain was low (2/10) and 90% of the patients that had previously received needle injections preferred PJI to needle injection. Depositions of TAC + FU were imaged reaching deep into the scar at levels corresponding to the reticular dermis. CONCLUSION: A single PJI injection containing 5-FU and TAC can significantly improve the height and pliability of HTS. PJI is favored by the patients and may serve as a complement to conventional needle injections, especially for patients with needle phobia.

A Comparison in Patient Comfort Using Conventional Syringe and Needleless Jet Anesthesia Technique in Periodontal Surgery-A Split-Mouth Randomized Clinical Trial.

Background and Objectives: Periodontal surgery requires local anesthetic coverage to alleviate patient discomfort. Needles and injections can engender feelings of fear and anxiety in individuals. This study aimed to assess the level of comfort and anxiety in patients during the administration of local anesthesia using needleless jet anesthesia (JA) when compared to a conventional syringe (CS) in periodontal surgery. Method and Materials: 60 sites were designated for injection in a split-mouth design in 30 subjects who required periodontal surgery. Local anesthesia was administered in two appointments scheduled one week apart using either a JA system or a CS. The Visual Analogue Scale (VAS), Verbal Rating Scale (VRS), and Beck's anxiety inventory were used to report the pain and anxiety levels while injecting local anesthesia. Statistical analysis of the results was performed using the Shapiro-Wilks test and Paired t-test. Results: Patients reported greater comfort with JA. The VAS and VRS values were statistically significant-(p = 0.003) and (p = 0.001), respectively. Patients showed fear and were nervous about receiving a local anesthetic using a CS. A few subjects experienced lingering pain with the CS, whereas greater comfort and no lingering soreness were reported post-operatively at the site of JA administration. Conclusions: This study provides the first comprehensive assessment of using JA for periodontal surgical procedures. Lower pain scores were consistently observed with the use of jet injectors. Patients were at ease and reported lesser anxiety and greater comfort with jet injectors, making it ideally suited for providing local anesthesia in periodontal surgery.

Clinical endpoints of needle-free jet injector treatment: An in depth understanding of immediate skin responses.

OBJECTIVES: Needle-free jet injectors have been used in dermatological practice for many years. However, predefined clinical endpoints that guide physicians to choose optimal device settings have not been clearly defined. Here, we evaluate immediate skin responses as clinical endpoints for needle-free jet injector treatments. METHODS: We injected methylene blue in ex vivo human skin using an electronically-controllable pneumatic injector (EPI; 3-6 bar, 50-130 µl; n = 63), and a spring-loaded jet injector (SLI) with fixed settings (100 µl; n = 9). We measured the immediate skin papule (3D-camera), residual surface fluid (pipette), dermal dye distribution by estimating depth and width, and subcutaneous dye deposition. RESULTS: EPI with 4 bar and 100 µl resulted in the largest skin papule of 48.7 mm3 (35.4-62.6 mm3 ) and widest dermal distribution of 8.0 mm (5.5-9.0 mm) compared to EPI with 6 bar and 100 µl (p < 0.001, p = 0.018, respectively). The skin papule volume showed a significant moderate to high positive correlation with the width and depth of dye distribution in the dermis (rs = 0.63, rs = 0.58, respectively; p < 0.001 for both correlations). SLI showed high variability for all outcome measures. Finally, a trend was observed that a small skin papule (≤7 mm) and little residual surface fluid (≤10% of injection volume) were warning signs for subcutaneous deposition. CONCLUSIONS: The immediate skin papule and residual surface fluid correspond with dermal drug deposition and are relevant clinical endpoints for needle-free jet injector treatments in dermatological practice.

The Effectiveness of Jet (Needle-Free) Injector to Provide Anesthesia in Child Circumcision under Local Anesthesia.

OBJECTIVE: In our study, we aimed to evaluate the effectiveness of a needle-free (jet) injector in local anesthesia for circumcision. MATERIALS AND METHODS: A total of 64 children were divided into two groups as jet injector group (n = 32) and conventional needle group (n = 32). Ring block was applied 6-8 times with a jet injector that sprayed each time 0.1 ml (2 mg) of lidocaine in jet injector group. In conventional needle group, ring block was applied with 2 mg/kg lidocaine injection. Using FLACC (Face, Legs, Activity, Cry, Consolability) pain scale, pain score during local anesthetic injection, anesthesia start time and pain score during circumcision were determined for both groups. RESULTS: The mean age of the patients was 3.99 ± 1.41 years in jet injector group and 3.88 ± 1.33 years in conventional needle group. The mean FLACC pain score during the anesthesia procedure was 4.75 ± 0.25 in jet injector group, while it was 7.06 ± 0.24 in conventional needle group. FLACC pain scores were found to be significantly lower in jet injector group (p = 0.0001). During circumcision, the mean FLACC scores were 4.91 ± 0.29 and 2.31 ± 0.18 for jet injector group and conventional needle group, respectively. These FLACC pain scores were found to be significantly lower in conventional needle group (p = 0.0001). CONCLUSION: Our study showed that anesthesia using a jet injector can not provide sufficient analgesia so as to comfortably complete circumcision in pediatric circumcisions performed under local anesthesia.

Needle-free jet injection-induced small-droplet aerosol formation during intralesional bleomycin therapy.

OBJECTIVES: Needle-free jet injectors are frequently used in dermatological practice. Injection-generated small-droplet aerosols could be harmful upon inhalation when chemotherapeutics, like bleomycin, are used. Here, we aim to explore jet injector-induced small-droplet aerosol formation of bleomycin in relation to air ventilation and to provide safety measures for clinical practice. MATERIALS AND METHODS: With a professional particle sensor, we measured airborne aerosol particles (0.2-10.0 µm) after electronic pneumatic injection (EPI), spring-loaded jet injection (SLI), and needle injection (NI) of bleomycin and saline (100 µl) on ex vivo human skin. Three levels of air ventilation were explored: no ventilation, room ventilation, and room ventilation with an additional smoke evacuator. RESULTS: EPI and SLI induced significant small-droplet aerosol formation compared with none after NI (0.2-1.0 µm; no ventilation). The largest bleomycin aerosol generation was observed for the smallest particles (0.2-1.0 µm) with 673.170 (528.802-789.453) aerosol particles/liter air (EPI; no ventilation). Room ventilation and smoke evacuation led to a reduction of ≥99% and 100% of measured aerosols, respectively. CONCLUSION: Jet injectors generate a high number of small-droplet aerosols, potentially introducing harmful effects to patients and healthcare personnel. Room ventilation and smoke evacuation are effective safety measures when chemotherapeutics are used in clinical practice.

Small animal jet injection technique results in enhanced immunogenicity of hantavirus DNA vaccines.

DNA vaccine evaluation in small animals is hampered by low immunogenicity when the vaccines are delivered using a needle and syringe. To overcome this technical hurdle we tested the possibility that a device developed for human intradermal medicine delivery might be adapted to successfully deliver a DNA vaccine to small animals. Disposable syringe jet injection (DSJI) does not currently exist for small animals. However, a commercialized, human intradermal device used to to administer medicines to the human dermis in a 0.1 mL volume was evaluated in Syrian hamsters. Here, we found that hantavirus DNA vaccines administered to hamsters using DSJI were substantially more immunogenic than the same vaccines delivered by needle/syringe or particle mediated epidermal delivery (gene gun) vaccination. By adjusting how the device was used we could deliver vaccine to either subcutaneous tissues, or through the skin into the muscle. RNA and/or antigen expression was detected in epidermal, subepidermal and fibroblast cells. We directly compared six optimized and non-optimized hantavirus DNA vaccines in hamsters. Optimization, including codon-usage and mRNA stability, did not necessarily result in increased immunogenicity for all vaccines tested; however, optimization of the Andes virus (ANDV) DNA vaccine protected vaccinated hamsters from lethal disease. This is the first time active vaccination with an ANDV DNA vaccine has shown protective efficacy in the hamster model. The adaptation of a human intradermal jet injection device for use as a method of subcutaneous and intramuscular jet injection of DNA vaccines will advance the development of nucleic acid based medical countermeasures for diseases modeled in hamsters.

Needle-Free Injection Assisted Drug Delivery-Histological Characterization of Cutaneous Deposition.

BACKGROUND AND OBJECTIVES: Many cutaneous drug-delivery techniques rely on passive diffusion to deliver topical compounds to the skin. When attempting to deliver drugs to thicker lesions, such as skin tumors, modalities that do not rely on diffusion may serve as a better drug-delivery method. In this histological study, we aim to investigate the cutaneous delivery patterns of an electronic pneumatic needle-free injection device. STUDY DESIGN/MATERIALS AND METHODS: Needle-free-injection was investigated in 24 ex vivo porcine skin samples and one basal cell carcinoma (BCC) tissue sample. A needle-free injection device with a nozzle size of 200 µm delivered 80 µl compound ink (0.1 cc black ink: 5.0 cc saline) at low (30%/3.1 bar; n = 6 porcine skin; n = 1 BCC tissue), medium (50%/3.9 bar; n = 6 porcine skin), high (65%/4.6 bar; n = 6 porcine skin), and stacked (30 + 50%/3.1 + 3.9 bar; n = 6 porcine skin) pressures. Depth, width, and depth of maximum width of ink deposition were evaluated on histological slides. RESULTS: Depositions with small ink-lined vacuoles were seen intra-dermally in all samples, including the BCC tissue. Deposition depth was similar at low and medium pressures (924 vs. 994 µm; P = 0.873) but increased significantly with high pressure (1,564 µm; P = 0.010). When injections were stacked (3.1 + 3.9 bar), the depth remained similar to that of a single injection (931 µm; P = 1.000). The width of the deposition stayed comparable for low, medium, and high pressures when a single needle-free injection was performed (30% = 2,394 µm; 50% = 2,226 µm; and 65% = 2,757 µm; P = 0.09), but increased significantly with stacking (2,979 µm; P = 0.037). The depth of maximal width was superficially located in the papillary dermis at low and medium pressures (321 and 305 µm; P = 0.748) but shifted to the deeper reticular dermis with high pressure (950 µm; P = 0.004) and with stacking (734 µm; P = 0.004). CONCLUSIONS: In conclusion, with an electronically controlled, pneumatic needle-free injector, depth and width of a cutaneous deposition can be influenced by pressure and stacking, respectively. The pneumatic needle-free injection can potentially serve as a viable drug-delivery technique for cutaneous pathologies where dermal deposition is essential. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Is the jet injection effective for teeth extraction?

Pain control is achieved typically by means of injection of local anesthesia for invasive procedures to carry out procedures with as little pain or discomfort as possible. Although this method is highly effective, patients often fear more from the sight of a needle during administration of local anesthetic than from the treatment. Therefore, needleless local anesthesia with a jet injection device has been proposed. With the INJEX®, anesthetic solution is forced under high pressure into the oral mucosa, leading to mechanical infiltration of the compound through the mucosa. With this study, we aimed to show the effectiveness of the needleless injection for infiltrative anesthesia and compare the acceptance and efficacy between jet injection with INJEX and local infiltration anesthesia. 28 adult patients admitted to our department for tooth extraction were included in the study. Two symmetrical teeth in the same jaw were extracted from each of the patients. Jet injection with the INJEX® was performed on one side and classical (needle) infiltration anesthesia on the other side with 0.3 cc Ultracain DS forte (Sanofi Aventis, Istanbul, Türkiye) on buccal and lingual aspects and 0.1 cc on palatal aspects of the teeth. The difference between pain and discomfort scores experienced during tooth extraction was statistically significant (P = 0.026). Accordingly, the pain or discomfort score of the INJEX® method during tooth extraction was significantly higher. Jet injection with the INJEX® was not found to be effective for local infiltrative anesthesia especially teeth extractions. It may be more acceptable when using for previously classical local infiltration anesthesia by patients. The main problem with jet injection was the "pop" sound when the INJEX® device was pressed, and also inadequate suppyling the anesthesia.

Subcutaneous nicotine delivery via needle-free jet injection: A porcine model.

Subcutaneous delivery of nicotine was performed using a novel electrically-operated needle-free jet injector, and compared to hypodermic needle delivery in a porcine model. Nicotine was delivered as a single, one-milligram dose into the abdominal skin, formulated as a 50 microliter aqueous solution. Plasma levels of nicotine and cotinine, its main metabolite, were then monitored over 2 h, following which the injection site was excised for histological examination. No irritation or tissue damage were found at the injection sites, and the jet-injected nicotine exhibited comparable absorption into the systemic circulation to that injected using a conventional needle and syringe. The needle-free jet injection of nicotine is a promising and well tolerated method. The data presented from this porcine model will support a first in human trial towards a new promising nicotine replacement therapy.

Needle-free pneumatic injection device; histologic assessment using a rat model and parameter comparison in predicting collagen synthesis degree.

BACKGROUND: Needle-free pneumatic injections have been recently introduced to the field of dermatology to inject such substances as hyaluronic acid. However, data on the influence of various pneumatic injection parameters on collagen synthesis are lacking. OBJECTIVE: Compare the effect of diameter, pressure, and volume of a pneumatic injection jet on collagen synthesis and fluid dispersion pattern using a rat model. Investigate if the total work force of the injection jet is useful in predicting the degree of collagen synthesis. MATERIALS AND METHODS: We injected fluid with 1 mg/ml of hyaluronic concentration to adult rats. Different injection pressures and volumes were tested using devices with nozzles of different diameters. Collagen synthesis areas were then measured, and statistical analyses were performed. RESULTS: The area of collagen fibers increased for up to two months. The injection pressure and volume did not correlate with the degree of collagen synthesis. The nozzle diameter showed a significant after two and four weeks of injection. The total work force correlated with collagen synthesis 2, 4, and 8 weeks post-injection. (P = 0.043, 0.027, and 0.000, respectively). CONCLUSION: Collagen formation is more prominent 2 months post-hyaluronic acid injection than after 1 month when using a needle-free pneumatic injection device. The total work force, which is affected by both the nozzle diameter and injection pressure, can be helpful in predicting the degree of collagen synthesis. Lasers Surg. Med. 51:278-285, 2019. © 2019 Wiley Periodicals, Inc.

Needle-free delivery of DNA: Targeting of hemagglutinin to MHC class II molecules protects rhesus macaques against H1N1 influenza.

Conventional influenza vaccines are hampered by slow and limited production capabilities, whereas DNA vaccines can be rapidly produced for global coverage in the event of an emerging pandemic. However, a drawback of DNA vaccines is their generally low immunogenicity in non-human primates and humans. We have previously demonstrated that targeting of influenza hemagglutinin to human HLA class II molecules can increase antibody responses in larger animals such as ferrets and pigs. Here, we extend these observations by immunizing non-human primates (rhesus macaques) with a DNA vaccine encoding a bivalent fusion protein that targets influenza virus hemagglutinin (HA) to Mamu class II molecules. Such immunization induced neutralizing antibodies and antigen-specific T cells. The DNA was delivered by pain- and needle-free jet injections intradermally. No adverse effects were observed. Most importantly, the immunized rhesus macaques were protected against a challenge with influenza virus.

Needle-free jet versus conventional needle injection for local anesthesia in men undergoing surgical sperm retrieval.

BACKGROUND: Surgical sperm retrieval, requiring local anesthetic injection, is the most frequent surgical procedure in male infertility. However, needle phobia is common and may contribute to negative experiences or refusal of procedures employing needle injection. OBJECTIVES: The aim of this study was to compare the acceptability, safety, and efficacy of needle-free jet anesthetic technique (MadaJet) with conventional needle injection for surgical sperm retrievals in patients with azoospermia. MATERIALS AND METHODS: This single-blind randomized controlled trial (RCT) was included of 59 participants who underwent surgical sperm retrievals. Patients were randomly assigned to the needle-free jet (n = 29) or needle injection (n = 30) groups prior to undergoing the surgery. The primary endpoint was the pain score. RESULTS: Baseline characteristics were comparable between the two groups. The safety and adverse outcomes were also not statistically significant difference (p > 0.05). The pain score in patients using needle-free jet was significantly lower than that in patients using needle injection (p < 0.05). Patients in MadaJet group had a significantly lower discomfort score during (p < 0.001) and after (p = 0.01) injection than those in the needle injection group. However, there was no significant difference in the fear score (before, during, and after) of MadaJet and needle injection (p = 0.98, p = 0.74, and p = 0.94, respectively). The mean time to onset of anesthesia was much shorter in the MadaJet group as compared with needle injection (10 ± 4 vs. 157.5 ± 71 s, p < 0.001). However, the duration of anesthesia in patients using MadaJet was shorter compared with those using needle injection (44 ± 13 vs. 63 ± 26 min, p < 0.001). CONCLUSION: In conclusion, for local anesthesia in patients undergoing surgical sperm retrieval, MadaJet produces less pain and discomfort with quicker time to onset and offset of anesthesia compared with conventional needle injection.

Assessment of anesthetic properties and pain during needleless jet injection anesthesia: a randomized clinical trial

Abstract Pain due to administration of local anesthetics is the primary reason for patients' fear and anxiety, and various methods are used to minimize it. This study aimed to measure the degree of pain during administration of anesthesia and determine the latency time and duration of pulpal anesthesia using two anesthetic methods in the maxilla. Materials and Methods: A randomized, single-blind, split-mouth clinical trial was conducted with 41 volunteers who required class I restorations in the maxillary first molars. Local anesthesia was administered with a needleless jet injection system (experimental group) or with a carpule syringe (control) using a 30-gauge short needle. The method of anesthesia and laterality of the maxilla were randomized. A pulp electric tester measured the latency time and duration of anesthesia in the second molar. Visual analogue scale (VAS) was used to measure the degree of pain during the anesthetic method. Data were tabulated and then analyzed by a statistician. The t-test was used to analyze the differences between the groups for basal electrical stimulation. Duration of anesthesia and degree of pain were compared using the Mann-Whitney test. A 5% significance level was considered. Results: There was no statistical difference in the basal electrical stimulation threshold (mA) and degree of pain between the two methods of anesthesia (p>0.05). Latency time was 2 minutes for all subjects. The duration of pulpal anesthesia showed no statistical difference (minutes) between the two methods (p<0.001), with a longer duration for the traditional method of anesthesia (median of 40 minutes). Conclusions: The two anesthetics methods did not differ concerning the pain experienced during anesthesia. Latency lasted 2 minutes for all subjects; the traditional infiltration anesthesia resulted in a longer anesthetic duration compared with the needleless jet injection.

Survey on the practice of anaesthesiologists in inguinal hernia surgery in Galicia. / Encuesta sobre la práctica de los anestesiólogos en la cirugía de hernia inguinal en Galicia.

OBJECTIVES: To evaluate the preference in the anaesthetic technique by anaesthesiologists for the management of inguinal hernia surgery in Galicia. MATERIAL AND METHODS: Using the National Catalogue of Hospitals of the Ministry of Health and Consumer Affairs in Galicia, a questionnair was sent to the Heads of Anaesthesiology Service and Coordinators of the Postanaesthesia Care Unit (PACU) with 11 questions on the anaesthetic technique chosen by anaesthesiologists in the management of patients for inguinal hernia surgery, as well as their reasons. RESULTS: The questionnaire was sent to 11 hospitals: 8 with PACU and 3 District. A total of 94 professionals responded, 56% with more than 10 years of experience, who performed between 8-10 procedures/month (58%) on an outpatient basis (61.54%). The most used anaesthetic technique was intradural in 52.8%, compared to 41.8% of general anaesthesia. Respondents with more than 10 years of experience preferred spinal anaesthesia in 38.6% of cases, compared to those with less experience (6.8%) (P=.037). One in 4 of those who chose general anaesthesia used ultrasound-guided interfascial blocks (27.5%). The local anaesthetic most used in intradural anaesthesia was hyperbaric bupivacaine (70.8%) at doses higher than 7mg. CONCLUSION: Intradural anaesthesia with hyperbaric bupivacaine was the technique most chosen by anaesthesiologists for the management of inguinal hernia surgery. The anaesthetic techniques chosen among the different hospitals did not follow a homogenous distribution. In this survey, there was a tendency to choose the technique associated with the experience of the anaesthesiologist.