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Background

With the advancements in dentistry the treatments are done with high perfections and patient comfort. Noninvasive, methods reduce fear and anxiety of the patient on phobia of syringes and injections. Topical anesthesia satisfies all the above criteria.

Aim and objective

Comparison of the efficacy of topical application of lignocaine hydrochloride 5% gel and bupivacaine hydrochloride 5% gel for extraction of teeth.

Materials and methods

Lignocaine hydrochloride 5% gel and bupivacaine hydrochloride 5% gel are prepared with carbopol (thickening agent). 510 extractions with lignocaine hydrochloride gel 5% and bupivacaine hydrochloride gel 5% in equal numbers was undertaken. Parameters of onset of anesthesia, peak effects, pain, and disappearance of numbness, local irritation, bleeding and periodontal status of teeth to be extracted were taken into consideration.

Results

Onset and peak effect were faster with 5% lignocaine hydrochloride gel. 5% bupivacaine hydrochloride gel had longer duration of analgesia. Patients experienced more pain with bupivacaine. Grade 1 mobile posterior teeth were painful during extraction.

Conclusion

5% lignocaine hydrochloride gel is better than 5% bupivacaine hydrochloride gel as a topical anesthetic for extraction of grade II and grade III mobile teeth.

A vibrating dental local anesthesia attachment (Vibraject, LLC, Calif) based on the concept of the gate-control theory has been used in clinical practice. The theoretical advantage of the vibrating needle is that it reduces the injection pain. We evaluated the effectiveness of Vibraject in combination with an electrical injection device. Injections were given into the alveolar mucosa adjacent to the root apex of the maxillary lateral incisor in 10 volunteers. Vibraject was randomly applied to either the left or right side of the injection. No statistically significant decrease in pain scores was found at needle insertion or anesthetic injection. The clinical efficacy of Vibraject remains controversial.

In a study to investigate whether the quantitative assessment of temperature and vibration thresholds can improve the evaluation of the neurological symptoms in vibration syndrome 37 patients with neurological symptoms (paraesthesias, numbness, pain) in the hands who had worked with hand held vibrating tools and 46 healthy controls not exposed to vibration were examined. Temperature thresholds were measured on the thenar eminence and on the volar side of the second and third fingers held together. Vibration thresholds were determined on the dorsum of the hand and on the dorsal side of the second and fifth fingers proximal to the nail. The neutral zone between thresholds for warmth and cold was much wider in the patients than in the controls. Patients older than 45 had higher vibration thresholds than controls. Electroneurography was abnormal in 18 of 34 patients and a carpal tunnel syndrome was diagnosed in six subjects. This investigation is thus indicated in patients with neurological symptoms. Seven of the patients with normal electroneurographic findings had impaired temperature or vibration thresholds or both. Determination of sensory thresholds seems to add valuable information and the methods are, by contrast with electroneurography, easily adapted to the screening of exposed groups outside hospital. Our results indicate that thin myelinated and unmyelinated nerve fibres might be damaged in the vibration syndrome.

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OBJECTIVES—To assess the risk of disturbed thermal perception relative to exposure to vibration, to investigate a possible exposure-response relation and to analyse a possible relation between thermal perception and sensory symptoms.
METHODS—The study was based on a cross section of 123 male workers exposed to vibration and 62 male workers who were not exposed. Thermal perception of cold, warmth, and heat pain was bilaterally determined from the thenar eminence by the method of limits. Perception of cold and warmth were also tested in the second digit. Personal energy equivalent exposure to vibration was measured for all subjects. Vibration was measured in accordance with International Standards Organisation (ISO) 5349 and assessed separately for the left and right hand.
RESULTS—Combining exposure times and intensities gave the left hand an 0.80 exposure to vibration compared with the right. The risk of having contracted reduced thermal perception was increased at all test sites. The risk was higher for the thenar measurements than the finger measurements. A yearly extra contribution of 4000 mh/s2 in cumulative exposure increases the risk of contracting a wider neutral zone by 18% (95% confidence interval (95% CI) 1.06 to 1.32) for the right and 18% (1.05 to 1.32) for the left hand side. Subjects with symptoms of nocturnal paraesthesia had a rate ratio (95% CI) of 2.80 (1.17 to 6.67) for the right hand and 2.72 (1.12 to 6.63) for the left hand for increased neutral zones at the thenar eminence.
CONCLUSIONS—The results indicate thermal sensory impairment related to cumulative exposure to vibration. The effect appeared at vibration levels below the current guiding standard. Quantitative sensory testing of thermal perception offers the chance to assess this specific hazard to the peripheral sensorineural system associated with hand intensive work entailing vibration.


Keywords: quantitative thermal perception; heat pain; vibration; temperature threshold

OBJECTIVES: To introduce an electric ear syringe into an emergency department and evaluate its use in the removal of foreign bodies from the external auditory canal. METHODS: Report of the use of a new device (the Propulse electric ear syringe) in an emergency department with a retrospective audit of the management of all cases of aural foreign bodies during one year. RESULTS: Almost 60% of the 84 patients who presented with foreign bodies in the auditory canal were children. Staff chose to treat over half of all patients with aural foreign bodies with the electric ear syringe. The overall success rates for the removal of the foreign bodies were: electric syringe, 93% in adults and 88% in children and instrumentation, 68% in adults and 50% in children. CONCLUSIONS: Irrigation with an electric ear syringe is an effective method of removing foreign bodies from the external auditory canal. The device tested was safe, inexpensive, easy to use, and readily acceptable to both adults and children. The availability of an electric ear syringe in an emergency department can avoid the need for specialist referral and the subsequent removal of foreign bodies under general anaesthesia.

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Purpose. Little attention has been given to syringe design and local anaesthetic administration methods. A microprocessor-controlled anaesthetic delivery device has become available that may minimize discomfort during injection. The purpose of this study was to document the pain experience associated with the use of this system and to compare it with use of a conventional syringe. Methods. A prospective, randomized clinical trial was designed. 40 patients undergoing carpal tunnel release were block randomized according to sex into a two groups: a traditional syringe group and a microprocessor-controlled device group. The primary outcome measure was surgical pain and local anaesthetic administration pain. Secondary outcomes included volume of anaesthetic used and injection time. Results. Analysis showed that equivalent anaesthesia was achieved in the microprocessor-controlled group despite using a significantly lower volume of local anaesthetic (P = .0002). This same group, however, has significantly longer injection times (P < .0001). Pain during the injection process or during surgery was not different between the two groups. Conclusions. This RCT comparing traditional and microprocessor controlled methods of administering local anaesthetic showed similar levels of discomfort in both groups. While the microprocessor-controlled group used less volume, the total time for the administration was significantly greater.

The use of ultrasonic vibrations for the cutting of bone was first introduced two decades ago. Piezoelectric surgery is a minimally invasive technique that lessens the risk of damage to surrounding soft tissues and important structures such as nerves, vessels, and mucosa. It also reduces damage to osteocytes and permits good survival of bony cells during harvesting of bone. Grafting with intraoral bone blocks is a good way to reconstruct severe horizontal and vertical bone resorption in future implants sites. The piezosurgery system creates an effective osteotomy with minimal or no trauma to soft tissue in contrast to conventional surgical burs or saws and minimizes a patient's psychological stress and fear during osteotomy under local anesthesia. The purpose of this article is to describe the harvesting of intraoral bone blocks using the piezoelectric surgery device.

Objective

To compare the effectiveness and convenience of a pen device for the self-administration of follitropin β with a conventional syringe delivering follitropin β solution in patients undergoing IVF-ET.

Methods

GnRH agonist long protocol was used for controlled ovarian stimulation (COS) in all subjects. A total of 100 patients were randomized into the pen device group or the conventional syringe group on the first day of COS. Local tolerance reactions were assessed within 5 minutes, at 1 hour and at 3 hours after each injection. On the day of hCG injection, patients were asked to rate their overall pain and convenience experienced with self-injection on a visual anlaogue scale (VAS).

Results

There were no differences in patients' characteristics between the two groups. The duration of COS was significantly shorter in the pen device group than in the conventional syringe group. Patients included in the pen device group needed a significantly smaller amount of follitropin β. However, no differences between the two groups were found in IVF results and pregnancy outcome. The incidence of local pain within 5 minutes, at 1 hour and at 3 hours after the injection was significantly lower in the pen device group. VAS scores indicated that injections using the pen device were significantly less painful and more convenient.

Conclusion

The pen device for self-administration of follitropin β is less painful, safer and more convenient for the patients, and can be more effective because of the shorter duration and smaller dose of follitropin β when compared with the conventional syringe.

This paper presents a computational method for detecting vibrations related to eccentricity in ultra precision rotation devices used for nano-scale manufacturing. The vibration is indirectly measured via a frequency domain analysis of the signal from a piezoelectric sensor attached to the stationary component of the rotating device. The algorithm searches for particular harmonic sequences associated with the eccentricity of the device rotation axis. The detected sequence is quantified and serves as input to a regression model that estimates the eccentricity. A case study presents the application of the computational algorithm during precision manufacturing processes.

The effects of continuous segmental vibration on the biceps femoris (BF) nociceptive flexor reflexes elicited by painful electrical stimulation of the sural nerve at the ankle were investigated in 25 normal subjects. During vibration of 100 Hz frequency, applied either on ipsilateral or contralateral foot skin, the nociceptive BF flexor reflexes increased in amplitude. Marked facilitation was prolonged even 20 minutes after vibration ceased. Pain sensation described by subjects did not change significantly except that radiation of pain was reduced in some cases. The results could not be explained by current views of reflex sensitisation, dishabituation, or the gate control theory.

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Background and Objectives:

To compare resection time and collateral thermal damage of 3 currently available ultrasonically activated devices in laparoscopic small bowel surgery.

Methods:

AutoSonix®, SonoSurg®, and UltraCision® were compared in laparoscopic small bowel mesentery resection in a porcine model. A resection was defined as 12 endarcade arteries supplying the intended bowel segment. Vessels were divided 1 cm off the bowel wall. AutoSonix®, SonoSurg®, and UltraCision® were comparable for blade length and type, cutting mechanism, handle ergonomics, and vibration amplitude, but not well matched for vibration frequency (55.5;23.5;55.5 kHz), working shaft diameter (5;11;10mm) and length (29;33;34cm), respectively. A sample size of 114 was calculated to detect a 25% difference with 90% power at a 5% significance level. Resections were allocated to devices by block randomization. Analysis of variance and pairwise Scheffe tests were used for multiple comparisons, and a Kaplan-Meier plot was drawn to confirm differences in resection time with each device. A pathologist blind to the devices evaluated bowel wall biopsies for thermal damage.

Results:

Procedures as allocated comprised 114 resections (38 with each device). UltraCision® median resection time of 5160 (range 2340-7860) seconds was significantly longer (P=0.0001). The difference in resection time between AutoSonix® (median 3420, range 1860-8760 s) and SonoSurg® (median 3660, range 1800-6900 s) did not reach statistical significance. A microscopy revealed no thermal damage.

Conclusions:

Laparoscopic resection time for porcine bowel mesentery was shorter with AutoSonix® or SonoSurg® than with UltraCision®, and no thermal damage to the bowel wall was found.

Background:

All established disease-modifying drugs for multiple sclerosis require parenteral administration, which can cause difficulties for some patients, sometimes leading to suboptimal adherence. A new electronic autoinjection device has been designed to address these issues.

Methods:

Patients with relapsing multiple sclerosis currently receiving subcutaneous or intramuscular interferon beta-1a, interferon beta-1b, or glatiramer acetate completed an online questionnaire (July 4–25, 2008) that surveyed current injection practices, experiences with current injection methods, and impressions and appeal of the new device.

Results:

In total, 422 patients completed the survey, of whom 44% used autoinjectors, 43% prefilled syringes, and 13% syringes and vials; overall, 66% currently self-injected. Physical and psychological barriers to self-injection included difficulty with injections, needle phobia, and concerns over correct injection technique. Only 40% of respondents were “very satisfied” with their current injection method. The new electronic autoinjector was rated as “very appealing” by 65% of patients. The benefits of the new device included the ability to customize injection settings and to review dosing history.

Conclusion:

New technologies may help patients overcome physical and psychological barriers to self-injection. The combination of a reliable and flexible autoinjection device with dose-monitoring technology may improve communication between health care professionals and patients, and improve treatment adherence.

Melzack and Wall’s Gate Control Theory of Pain laid the theoretical groundwork for a role of spinal inhibition in endogenous pain control. While the Gate Control Theory was based on the notion that spinal inhibition is dynamically regulated, mechanisms underlying the regulation of inhibition have turned out to be far more complex than Melzack and Wall could have ever imagined. Recent evidence indicates that an exquisitely sensitive form of regulation involves changes in anion equilibrium potential (Eanion), which subsequently impacts fast synaptic inhibition mediated GABAA, and to a lesser extent, glycine receptor activation, the prototypic ligand gated anion channels. The cation-chloride co-transporters (in particular NKCC1 and KCC2) have emerged as proteins that play a critical role in the dynamic regulation of Eanion which in turn appears to play a critical role in hyperalgesia and allodynia following peripheral inflammation or nerve injury. This review summarizes the current state of knowledge in this area with particular attention to how such findings relate to endogenous mechanisms of hyperalgesia and allodynia and potential applications for therapeutics based on modulation of intracellular Cl− gradients or pharmacological interventions targeting GABAA receptors

Anxiety is a relevant problem in dental practice. The Visual Analogue Scale for Anxiety (VAS‐A), introduced in dentistry in 1988, has not yet been validated in large series. The aim of this study is to check VAS‐A effectiveness in more than 1000 patients submitted to implantology. The VAS‐A and the Dental Anxiety Scale (DAS) were administered preoperatively to 1114 patients (459 males and 655 females, age 54.7 ± 13.1 years). Statistical analysis was conducted with Pearson correlation coefficient, the receiver operating characteristic (ROC) curve, and McNemar tests. A close correlation between DAS and VAS‐A was found (r  =  0.57, P < .0001); the VAS‐A thresholds of dental anxiety and phobia were 5.1 and 7.0 cm, respectively. Despite a significant concordance of tests in 800 cases (72%), disagreement was found in the remaining 314 cases (28%), and low DAS was associated with high VAS‐A (230 cases) or vice versa (84 cases). Our study confirms that VAS‐A is a simple, sensitive, fast, and reliable tool in dental anxiety assessment. The rate of disagreement between VAS‐A and DAS is probably due to different test sensitivities to different components of dental anxiety. VAS‐A can be used effectively in the assessment of dental patients, using the values of 5.1 cm and 7.0 cm as cutoff values for anxiety and phobia, respectively.

Summary

We have replaced the periodic Prandtl–Tomlinson model with an atomic-scale friction model with a random roughness term describing the surface roughness of micro-electromechanical systems (MEMS) devices with sliding surfaces. This new model is shown to exhibit the same features as previously reported experimental MEMS friction loop data. The correlation function of the surface roughness is shown to play a critical role in the modelling. It is experimentally obtained by probing the sidewall surfaces of a MEMS device flipped upright in on-chip hinges with an AFM (atomic force microscope). The addition of a modulation term to the model allows us to also simulate the effect of vibration-induced friction reduction (normal-force modulation), as a function of both vibration amplitude and frequency. The results obtained agree very well with measurement data reported previously.

Hypnosis is used as part of a psychological approach in dealing with phobic patients. The patient focuses on the stimuli of images offered by the therapist's voice. The critical faculty is bypassed, and selective thinking is established. The induction is the choice of the therapist, and imagery is introduced using numerical concepts associated with left-brain-related logic rather than right-brain-related nonverbal emotionality.1,2 There is an emotional component in the perception of pain, and this is a large factor in the development of dental phobia.3 Clinical skill and a sympathetic manner are not sufficient to ensure absence of pain perception in the patient: there must be a lack of awareness of any of the stimuli of dentistry. The hypnotic diversion of attention from dental treatment, aiming at the elimination of the emotional perception of pain, is described in this article.

Given daily, low molecular weight (LMW) heparins are established for prophylaxis against deep vein thrombosis (DVT). We describe delivery by a novel, needle-less device that is virtually painless in action. Its use could provide benefits for patients in terms of comfort both psychologically and physically, and for healthcare workers in terms of safety from needle-stick injury. Patients undergoing elective surgery received LMW heparin delivered subcutaneously by either a standard needle and syringe or by the needle-less injection device, J-Tip. Pain was scored at the time of injection and plasma anti-factor Xa levels compared between the two methods of drug delivery 4 h later: 29 patients received LMW heparin delivered by the J-Tip and 31 patients by standard needle and syringe. The J-Tip was significantly more comfortable for the patient as the method of drug delivery (P < 0.001). When delivered by the J-Tip, LMW heparin was equally as efficacious, as plasma anti-factor Xa levels were similar for both methods of delivery (P < 0.42). In summary, delivery of LMW heparin by the J-Tip device was both comfortable and effective. These findings, taken in conjunction with its ease of use and complete freedom from risk of needle-stick injury might encourage further examination and use of this type of product.

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The measurement of hand-transmitted vibration converts oscillatory movements to a form in which they can be evaluated with respect to human responses and assessed for their acceptability. This paper presents methods of measurement, evaluation, and assessment currently advocated in standards and other forms of guidance. The degree to which the methods of evaluating different frequencies, directions, and durations of vibration affect the assessment of vibration on different tools is illustrated. With the frequency weighting currently used to allow for the effects of different frequencies there is little need to measure vibration at frequencies as high as 1000 Hz; this has significant implications to the design and evaluation of proposed antivibration devices, including gloves. Without the current frequency weighting, vibration at frequencies greater than 250 Hz can contribute to the magnitude of the vibration, but many common causes of injury from hand-transmitted vibration have their dominant components of vibration below 250 Hz. On many powered tools, although the dominant frequency of vibration is the same before and after frequency weighting, the reported magnitude of vibration is greatly affected by the frequency weighting. On tools with dominant low frequencies, their vibration is rated as being of far greater importance relative to other tools when considering frequency-weighted acceleration than when considering unweighted acceleration. It is shown that the effect of considering three axes of vibration as opposed to one axis has a greater effect on some tools than on others. The uncertainties and assumptions involved in the measurement, evaluation, and assessment of hand-transmitted vibration are reviewed. It is suggested that whereas current decisions on health and welfare should be based on current assessment methods, the measurement and evaluation of hand-transmitted vibration should involve the collection and reporting of data which allow other interpretations in the future.

We report that polarization-shaped mid-infrared (IR) pulses can be used to enhance the vibrational population of one mode over another in a coupled molecular system. A genetic algorithm and a new mid-IR polarization shaper were used to alter the relative vibrational excitation of the two carbonyl stretching modes in Mn(CO)5Br. One mode could be selectively enhanced over the other by 2–3 times. Control over the polarization leads to better optimization than phase-only control. Several possible mechanisms that indicate how polarization shaping leads to selective vibrational excitation are discussed using a formalism that separates polarization shaping effects on the signal strength from amplitude or phase shaping. The techniques introduced herein will have broad applications in quantum gating schemes, controlling ground state chemistry and enhancing the sensitivity of multidimensional IR and visible spectroscopies.

A hand-arm vibration syndrome occurs in some workers who use hand held vibrating tools. It is recognised to consist of white fingers, diffusely distributed finger neuropathy, pain in the arm and hand, and a small excess risk of osteoarthrosis from percussion to the wrist and elbow. Carpal tunnel syndrome is mainly due to ergonomic factors other than vibration, but certain factors related to vibration may contribute to its development. A decrease in muscle power induced by vibration, and excessive hearing deficit have been postulated. The assessment of a disorder suspected of being induced by vibration includes deciding whether there is a disorder and, if so, whether the symptoms can be caused by vibration. To decide whether the symptoms can be caused by vibration epidemiological documentation and pathogenically reasonable theories must exist. A causal diagnosis finally requires and epidemiological decision whether or not the factual exposure has elicited the patient's symptoms. Epidemiological data on the quantitative association between vibration and excessive risks of white fingers and diffusely distributed neuropathy are incomplete. The symptomatic diagnosis of white fingers is still mainly based on anamnestic information. Available laboratory tests are incapable of grading the severity of individual cases. Recording the finger systolic blood pressure during cold provocation is a method of symptomatic diagnosis with reasonable levels of specificity, sensitivity, and predictive value. For diffusely distributed neuropathy these levels are lower than desired. Electrodiagnostic tests for carpal tunnel syndrome have sufficient validity. Proper exposure evaluation must be based on an appreciation of the character of the vibration as well as effective duration and intermittency. If this is not taken into account, the number of hours of exposure and intensity of vibration are likely to be non-commensurable variables, and the simple product of them is a questionable dose measure. Separate models for risk evaluation of vascular and neurological disorders related to work with different tools and processes will have to be established. Ongoing research to obtain further data on exposure-response relations for neurological disturbances begins to yield encouraging results.

Abstract

All type 1 diabetes mellitus (T1DM) subjects and the majority of type 2 diabetes mellitus (T2DM) subjects at one time or another require insulin to sustain life. Syringes and pens are presently the most popular insulin delivery devices. Though in use for more than 3 decades, insulin pumps are now being more commonly used because of their unique ability to continuously infuse insulin, closely mimicking that of physiological secretion from a normal pancreas. Unlike insulin shots with syringes, pump infusion sites need to be changed less frequently. Scientific evidence from published studies have proven added benefit of insulin pumps in improving quality of life, normalizing sugars in recalcitrant diabetes, improving sexual function, and relieving the intractable pain of neuropathy. In the western world, pumps are commonly used with T1DM subjects, whereas in India 80% of pumpers are T2DM subjects. The success of insulin pump therapy depends on selection of the right candidate, extensive education, motivation, and implementing the sophisticated programs with skill. However, all affordable patients are not ideal candidates for pump therapy because for successful continuation of pump therapy other inclusion criteria should also be fulfilled. Among the other indications discussed are a high level of insulin resistance, brittle diabetes, chronic kidney disease on renal replacement therapy, and continuous glucose monitoring pattern strongly suggesting need for a variable basal insulin infusion rate. In International Diabetes Foundation data released in 2009, estimated diabetes prevalence for 2010 is 285 million, representing 6.4% of the world's adult population, with a prediction that by 2030 the number of people with diabetes will have increased to 438 million. Considering this massive growth in T2DM and its propensity after 10–15 years to lead to an insulin-deficient state, available evidence from studies is a compelling indication not to deny the benefits of continuous subcutaneous insulin infusion in selected T2DM subjects. This article aims at suggesting guidelines based on clinical experience and cultural diversity for India and developing countries.

Insulin pen devices have several advantages over the traditional vial-and-syringe method of insulin delivery, including improved patient satisfaction and adherence, greater ease of use, superior accuracy for delivering small doses of insulin, greater social acceptability, and less reported injection pain. In recent years, pens have become increasingly user-friendly, and some models are highly intuitive to use, requiring little or no instruction. Despite this progress, uptake of these devices in the United States has not matched that in many other areas of the world. There is a need for improved awareness of the current characteristics of insulin pen devices among United States health care professionals. Knowledge of the design improvements that have been incorporated into pens, both to address patient needs and as a result of the improved technology behind the device mechanics, is essential to promoting the use of insulin pen devices. This review highlights some of the practical aspects of pen use and discusses the factors to be considered when selecting among different insulin pens.

While occupational exposure to vibration is a common cause of acute and chronic musculoskeletal pain, eliminating exposure produces limited symptomatic improvement, and re-exposure precipitates rapid recurrence or exacerbation. To evaluate mechanisms underlying these pain syndromes, we have developed a model in the rat, in which exposure to vibration (60–80 Hz) induces, in skeletal muscle, both acute mechanical hyperalgesia as well as long-term changes characterized by enhanced hyperalgesia to a pro-inflammatory cytokine or re-exposure to vibration. Exposure of a hind limb to vibration produced mechanical hyperalgesia measured in the gastrocnemius muscle of the exposed hind limb, which persisted for ~2 weeks. When nociceptive thresholds had returned to baseline, exposure to a pro-inflammatory cytokine or re-exposure to vibration produced markedly prolonged hyperalgesia. The chronic prolongation of vibration- and cytokine-hyperalgesia induced by vibration was prevented by spinal intrathecal injection of oligodeoxynucleotide (ODN) antisense to protein kinase Cε, a second messenger in nociceptors implicated in the induction and maintenance of chronic pain. Vibration-induced hyperalgesia was inhibited by spinal intrathecal administration of ODN antisense to receptors for the type-1 tumor necrosis factor-α (TNFα) receptor. Finally, in TNFα-pretreated muscle, subsequent vibration-induced hyperalgesia was markedly prolonged.

Perspective

These studies establish a model of vibration-induced acute and chronic musculoskeletal pain, and identify the proinflammatory cytokine TNFα and the second messenger PKCε as targets against which therapies might be directed to prevent and/or treat this common and very debilitating chronic pain syndrome.

Objective

To evaluate the outcomes of arthrocentesis with the new highly controllable, one handed reciprocating procedure syringe compared with a conventional syringe.

Methods

100 arthrocentesis procedures were randomised between the reciprocating syringe and the conventional syringe. Outcome measures included patient pain, procedure duration, operator satisfaction, synovial fluid volume, cell counts, and complications.

Results

50 arthrocentesis procedures with the conventional syringe resulted in a mean (SD) procedure time of 3.39 (1.88) minutes, a mean VAPS (patient pain) score of 5.35 (3.15), and a mean VASS (operator satisfaction) score of 4.88 (1.92); 30 of the 50 subjects experienced moderate to severe pain (VAPS score 5 or greater) during arthrocentesis. In contrast, the reciprocating syringe resulted in a reduced procedure time of 1.94 (1.14) minutes (p<0.001), a reduced VAPS (patient pain) score of 2.54 (1.60) (p<0.001), and an increased VASS (operator satisfaction) score of 8.91 (0.79) (p<0.001). Only five of the 50 of subjects experienced moderate to severe pain with the reciprocating syringe. Synovial cell counts were similar between the two syringes (p>0.05), but there was a trend toward greater volume (greater synovial fluid yield) and fewer red blood cells with the reciprocating syringe.

Conclusions

Arthrocentesis with a conventional syringe results in moderate to severe pain in 60% of subjects. The reciprocating syringe prevents significant pain, reduces procedure time, and improves physician performance of arthrocentesis. The reciprocating syringe is superior to the conventional syringe in arthrocentesis.

A micro-advancer device that positions a narrow-gauge needle within the vitreous humor of the rat eye is described. The device is compact, simple and inexpensive to manufacture. It consists of an outer guard needle and an inner injection needle that is advanced through the guard needle. With the rat held in a stereotaxic holder and the globe fixed to a stabilizing ring, the outer 25-gauge guard needle is advanced through the sclera using a standard micromanipulator. The inner 31-gauge injection needle is then advanced through the guard needle with a manually controlled leadscrew and carriage mechanism. The inner injection needle is attached to a Hamilton syringe and can be positioned to within microns of the retinal surface under visual observation through a microscope. The injection needle is fixed to the device by a quick-release clamp on the carriage and can be rapidly exchanged while the guard needle remains in place in the vitreous. This permits different solutions to be injected sequentially into the vitreous humor. Recording electrodes, stimulating electrodes, and optical fibers can also be advanced through the guard needle and positioned accurately near the retinal surface or within the retina.