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

Efficacy of EMLA for Office-based Andrology Procedures Under Local Anesthesia: A Randomized Control Trial

OBJECTIVE

To evaluate the effectiveness of Eutectic Mixture of Local Anesthetic (EMLA), a topical anesthetic cream, in office-based invasive andrological procedures such as hydrocelectomy, spermatocelectomy, and others, aimed at minimizing pain perception and enhancing the overall patient experience.

METHODS

A double-blinded randomized controlled trial was conducted for patients undergoing scrotal andrology surgeries under LA. Power calculation was performed with an estimated sample size of 72. Participants were randomly assigned in a 1:1 ratio to topical EMLA + LA versus LA alone. In the post-operative recovery area, patient will be asked to complete a VAS questionnaire rating pain with LA administration and pain with procedure. Analysis comparing VAS pain scores of both groups was performed using the independent sample t-test method.

RESULTS

Seventy-two patients were included in our analysis, with 36 in the control and 36 in the intervention arm. For patient pain with administration of LA, the control arm reported an average VAS pain score of 4.31, compared to 3.72 in the intervention arm (P = .319). For patient pain with procedure, patients in the control arm reported a median VAS pain score of 3.47 compared to 3.03 (P = .432) in the intervention arm. Overall, 86% (62/72) of patients reported that they would either be "very likely" (4/5) or "highly likely" (5/5) to undergo future procedures under local anesthetic.

CONCLUSION

While performing scrotal surgeries under LA appears to be well tolerated and a feasible option, the application of EMLA cream does not appear to significantly alter patient-reported outcomes.

Immune efficacy of a candidate porcine reproductive and respiratory syndrome vaccine rHN-NP49 administered by a Needle-free intradermal delivery system in comparison with intramuscular injection

Porcine reproductive and respiratory syndrome (PRRS) is one of the major drivers of economic loss in the swine industry worldwide. In commercial pig production, vaccination is the first option in an attempt to control infectious diseases. Pigs are therefore often immunized with different vaccines, and almost all of them are delivered via the intramuscular (IM) route. However, the IM injection may result in physical damage, stress reactions, and is labor demanding. An alternative route is urgently needed to reduce the disadvantages of conventional vaccination. In this study, a needle-free intradermal (ID) delivery system was evaluated for delivering a live PRRS vaccine as compared with the traditional needle-syringe method. Fifty-two 4-week-old piglets were divided into six groups: piglets in groups A-C were immunized using ID delivery system with 10⁴, 10⁵ and 10⁶ TCID₅₀ of PRRS candidate vaccine strain rHN-NP49, respectively; piglets in group D were immunized IM with 10⁵ TCID₅₀ of rHN-NP49; and group E and F were used as challenge and control groups, respectively. At 28 days post vaccination, piglets in group A to E were challenged with a lethal dose of highly-pathogenic PRRSV. Similar results were found in viremia and antibody response among the ID and IM groups during the immunization stage. After challenge, similar results were found in average body weight gain, viral shedding, serum viral load, and clinical score among the immunization groups, with a higher protection ratio in the ID group compared with IM group with the same immunization dose. These results demonstrated that the ID delivery system could provide similar or even better protection compared with IM route, and could be an effective route for PRRS vaccination.

A liquid breakdown driven non-invasive microjet injection system

The purpose of this study was to develop a microjet having fully skin-penetrable jet speed, moderately small volume, and highly repeatable injection, and eventually providing a device with medical efficacy for less tissue destruction and pain. The injector allows a small volume of drug stream (0.1-1.7 µL) to flow out at a frequency of ~16 Hz, and employs two different sources of energy, namely electrical and optical, which are converted into kinetic energy of the penetrating drug solution using liquid breakdown (dielectric or laser-induced). The medical efficacy of the microjet injection was evaluated through ex-vivo and in-vivo procedures in a mouse model. Both sources of liquid breakdown generate a skin-penetrable jet speed of 200-330 m/s. These fast and repetitive jets in a small volume pass through the epidermis to exert their efficacy. The driving pressure provided by dielectric breakdown showed an extensive increase per input energy increase, which is deemed appropriate for deep skin penetration. In contrast, the laser-induced breakdown exhibited a saturation in jet speed with increasing input energy, which is indicative of a low energy conversion efficiency. The results are promising for medical procedures that require uniform drug injection over a large area, and small dosage control during intradermal procedures.

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.