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At least 91 records · Page 5Linked to original sources

PubMed2004

Changes in public order after the opening of a medically supervised safer injecting facility for illicit injection drug users.

BACKGROUND: North America's first medically supervised safer injecting facility for illicit injection drug users was opened in Vancouver on Sept. 22, 2003. Although similar facilities exist in a number of European cities and in Sydney, Australia, no standardized evaluations of their impact have been presented in the scientific literature. METHODS: Using a standardized prospective data collection protocol, we measured injection-related public order problems during the 6 weeks before and the 12 weeks after the opening of the safer injecting facility in Vancouver. We measured changes in the number of drug users injecting in public, publicly discarded syringes and injection-related litter. We used Poisson log-linear regression models to evaluate changes in these public order indicators while considering potential confounding variables such as police presence and rainfall. RESULTS: In stratified linear regression models, the 12-week period after the facility's opening was independently associated with reductions in the number of drug users injecting in public (p < 0.001), publicly discarded syringes (p < 0.001) and injection-related litter (p < 0.001). The predicted mean daily number of drug users injecting in public was 4.3 (95% confidence interval [CI] 3.5-5.4) during the period before the facility's opening and 2.4 (95% CI 1.9-3.0) after the opening; the corresponding predicted mean daily numbers of publicly discarded syringes were 11.5 (95% CI 10.0-13.2) and 5.4 (95% CI 4.7-6.2). Externally compiled statistics from the city of Vancouver on the number of syringes discarded in outdoor safe disposal boxes were consistent with our findings. INTERPRETATION: The opening of the safer injecting facility was independently associated with improvements in several measures of public order, including reduced public injection drug use and public syringe disposal.

British Columbia↗

PubMed2006

"The first shot": the context of first injection of illicit drugs, ongoing injecting practices, and hepatitis C infection in Rio de Janeiro, Brazil.

The context of first drug injection and its association with ongoing injecting practices and HCV (hepatitis C virus) infection were investigated. Injection drug users (IDUs) (N = 606) were recruited in "drug scenes" (public places, bars) in Rio de Janeiro, Brazil, interviewed, and tested for HCV. Sharing of needles/syringes was more prevalent at the first injection (51.3%) than at the baseline interview (36.8%). Those who shared syringes/needles at first injection were more likely to be currently engaged in direct/indirect sharing practices. Among young injectors (< 30 years), those reporting sharing of needles/ syringes at the first injection were about four times more likely to have been infected by HCV. Hepatitis C virus prevalence among active IDUs (n = 272) was 11%. Prison history and longer duration of drug injection were identified as independent predictors of HCV infection. To effectively curb HCV transmission among IDUs and minimize harms associated with risk behaviors, preventive strategies should target individuals initiating drug injection beginning with their very first injection and discourage the transition from non-injecting use to the self-injection of illicit drugs.

Brazil↗

PubMedDate not supplied

Reduction of ammonia emission by shallow slurry injection: injection efficiency and additional energy demand.

Ammonia (NH3) emission from livestock production causes undesirable environmental effects and a loss of plant-available nitrogen. Much atmospheric NH3 is lost from livestock manure applied in the field. The NH3 emission may be reduced by slurry injection, but slurry injection in general, and especially on grassland, increases the energy demand and places heavy demands on the slurry injection techniques used. The reduction in NH3 emission, injection efficiency, and energy demand of six different shallow slurry-injection techniques was examined. The NH3 emission from cattle slurry applied to grassland was reduced by all the injectors tested in the study, but there were major differences in the NH3 reduction potential of the different types of injectors. Compared with the trailing hose spreading technique, the NH3 loss was reduced by 75% when cattle slurry was injected using the most efficient slurry injection technique, and by 20% when incorporated by the least efficient injection technique. The reduction in NH3 emission was correlated with injection depth and the volume of the slot created. The additional energy demand for reducing ammonia emissions by slurry injection was approximately 13 000 kJ ha(-1) for a 20% reduction and 34 000 kJ ha(-1) for a 75% reduction. The additional energy demand corresponds to additional emissions of, respectively, 5.6 and 14.5 kg CO2 per ha injected.

Agriculture↗

PubMed2002

Association between first injection risk behaviors and hepatitis C seropositivity among injecting drug users.

HCV infection is rapidly acquired after drug addicts first inject drug intravenously. The risk behaviors accompanying the first intravenous substance injection are not well known. We used in 1997 a structured questionnaire to investigate the relationships between risk behaviors at the first injection and current reported HCV status. We interviewed 151 injecting drug users from four treatment centers and one prison in Paris. Risk markers for reported HCV seroconversion were explored by use of logistic regression models. One hundred and forty-three injecting drug users (95%) agreed to participate in the study. At the first injection, 50% shared preparation equipment; 22% borrowed and 26% lent injecting equipment. At the time of the study, 46% reported that they were HCV-positive. Sharing preparation equipment (odds ratio=3.1; 95% confidence interval: 1.2-7.8) and lending injection equipment (odds ratio=3.0; 95% confidence interval: 1.1-8.5) during the first injection were independently associated with reported HCV seropositivity. The high-risk behaviors accompanying the first intravenous injection of drugs justifies the implementation of specific prevention measures, aimed at young drug users who have not started to inject.

Adult↗

PubMed2003

Potential use of safer injecting facilities among injection drug users in Vancouver's Downtown Eastside.

BACKGROUND: The Vancouver Coastal Health Authority will initiate North America's first sanctioned safer injecting facility, as a pilot project, on Sept. 15, 2003. The analyses presented here were conducted to estimate the potential use of safer injecting facilities by local illicit injection drug users (IDUs) and to evaluate the potential impact of newly established Health Canada restrictions and current police activities on the use of the proposed facility. METHODS: During April and May 2003, we recruited active IDUs in Vancouver's Downtown Eastside to participate in a feasibility study. We used descriptive and univariate statistics to determine potential use of a safer injecting facility and to explore factors associated with willingness to use such a facility with and without federal restrictions and police presence. RESULTS: Overall, 458 street-recruited IDUs completed an interviewer-administered survey, of whom 422 (92%) reported a willingness to use a safer injecting facility. Those expressing willingness were more likely to inject in public (odds ratio [OR] 3.9, 95% confidence interval [CI] 1.9-8.0). When the restrictions in the Health Canada guidelines were considered, only 144 (31%) participants were willing to use a safer injecting facility. IDUs who inject alone were more likely (OR 1.8, 95% CI 1.0-3.1) and women were less likely (OR 0.6, 95% CI 0.4-0.9) to be willing to use a safer injecting facility operating under these restrictions. Only 103 (22%) of the participants said they would be willing to use a safer injecting facility if police were stationed near the entrance. INTERPRETATION: Most IDUs participating in this study expressed a willingness to use a safer injecting facility. However, willingness declined substantially when the IDUs were asked about using a facility operating under selected Health Canada restrictions and in the event that police were stationed near the entrance.

Adult↗

PubMed1997

Injecting-related harm and treatment-seeking behaviour among injecting drug users.

AIMS: This study aims to identify the physical harm associated with injecting drug use and examine the treatment-seeking behaviour of injecting drug users (IDUs). Specific attention is given to the factors associated with presentation and non-presentation of injecting-related problems. DESIGN: Participants were interviewed by research staff using a semi-structured questionnaire, then physically examined by a medical team. SETTING: Needles exchanges in Glasgow. PARTICIPANTS: One hundred and twelve injecting drug users. FINDINGS: Respondents' accounts of their current injecting-related problems were found to be consistent with the clinician's findings, suggesting that IDUs are able to self-diagnose injecting-related harm. However, almost three-quarters had not sought help for these problems. Qualitative data suggest the main reasons for non-presentation, or delayed presentation, of injecting-related problems are normalization of injecting-related harm and a reluctance to attend available services. Almost half of those seeking treatment for injecting-related problems did so during an emergency or crisis. CONCLUSIONS: Low threshold services, such as needle exchanges, may have to take a more proactive stance to encourage injectors to present with injecting-related problems. This may help reduce injecting-related harms, especially the resulting medical complications, which would in turn relieve the pressure on other services such as hospital Accident and Emergency Departments.

Abscess↗

PubMed1997

The thigh may not be suitable as an injection site for patients self-injecting sumatriptan.

The objective of our study was to evaluate the differences between injection sites in the midthigh and the upper lateral quadrant of the gluteal area regarding the effect, depth of subcutaneous tissue, side effects, and patient preference in patients with cluster headache who self-inject 6 mg (0.5 ml) of sumatriptan. Our open, prospective clinical study was performed at the outpatient department of a Swedish university clinic. There were 19 male and one female subjects, 34 to 68 years old, suffering from cluster headache. We measured the subcutaneous tissue depth by ultrasound. Subjects performed four self-injections of sumatriptan, two in the thigh and two in the gluteal area. We evaluated the subcutaneous tissue depth from the skin surface to the muscle fascia, the effect on headache, side effects, and patient preference regarding the injection site. Subcutaneous tissue depth laterally in the thigh was 2 to 12 mm (median, 4 mm) and in the gluteal area was 34 to 68 mm (median, 45 mm). The needle of the self-injector protrudes 5 to 6 mm. Forty thigh and 39 gluteal injections were recorded. The effect on headache was equal. Following injection in thigh the patients experienced more bleeding (p < 0.001, chi 2); local pain (p < 0.05, chi 2); and a feeling of oppression in the head, neck, and chest area (p < 0.05, chi 2); compared with injections in the gluteal area. Fifteen patients preferred the gluteal area as the injection site after the study, two patients had no preference, and three preferred the thigh. When using the self-injector in the lateral aspect of the thigh, intramuscular injection is liable to occur frequently in male patients. This may explain the differences in local and general side effects observed in this study. The upper lateral quadrant of the gluteal area is a more suitable injection site for male, and some female, patients when using the sumatriptan self-injector.

Adult↗

PubMed1993

Jet-injected insulin is associated with decreased antibody production and postprandial glucose variability when compared with needle-injected insulin in gestational diabetic women.

OBJECTIVE: To elucidate the glycemic response and antibody formation in gestational diabetic women treated with insulin injected by a needle or a jet. The American Diabetes Association's position statement on jet injectors raised the concern that "insulin could be denatured as a result of forceful injection through a tiny port, which could lead to an increase in antibody formation" (Diabetes Care 11:600, 1988). However, the pharmacokinetics of jet-injected insulin suggest that it might be useful in controlling postprandial glucose levels. METHODS: We randomized 20 women with gestational diabetes mellitus (< 34 wk gestation) who required insulin to receive either jet-injected or needle-injected human NPH and regular insulin. Variables of interest were evaluated at the start of therapy, weekly until delivery, and 6-wk postpartum that included: 1) insulin antibodies in the mother and her infant, 2) HbA1c, 3) insulin dose, 4) fasting and postprandial glucose levels, and 5) subject acceptance and preference. RESULTS: Of the 10 women in the needle group, 6 developed significant insulin antibodies compared with 1 of 10 in the jet group (P < 0.001). HbA1c and insulin doses were the same in both groups. During the test meal, glucose levels in the jet group were significantly lower (P < 0.01), yet none of the women in the jet group experienced blood glucose < 70 mg/dl (3.89 mM) at 3-4 h after the meal, compared with 5 in the needle group (P < 0.001). Jet injection was associated with less variability (P < 0.001) in postprandial glucose values but slightly greater variability (P < 0.05) in fasting glucose. Jet-injected insulin was more readily accepted by subjects than needle injections. CONCLUSIONS: Jet injection is associated with a diminished antibody response and postprandial variability compared with needle-injected insulin. Thus, this warrants consideration as a therapeutic option for women with gestational diabetes mellitus and may also be applicable to nonpregnant, insulin-requiring diabetic patients.

Adult↗

PubMed2006

Comparison of hemostatic efficacy for epinephrine injection alone and injection combined with hemoclip therapy in treating high-risk bleeding ulcers.

BACKGROUND: Rebleeding occurs in 10% to 30% of bleeding ulcer patients receiving endoscopic epinephrine injection therapy. It remains unclear whether addition of a secondary clip therapy following epinephrine injection may reduce the rebleeding rate of high-risk bleeding ulcers. OBJECTIVE: To compare the efficacies of epinephrine injection alone and epinephrine injection combined with hemoclip therapy in treating high-risk bleeding ulcers. DESIGN: Prospective randomized controlled trial. SETTING: A medical center in Taiwan. PATIENTS: One hundred five bleeding ulcer patients with active spurting, oozing, nonbleeding visible vessels or adherent clots in ulcer bases. INTERVENTIONS: Endoscopic combination therapy (n = 52) or diluted epinephrine injection alone (n = 53). MAIN OUTCOME MEASUREMENTS: Initial hemostasis rates and recurrent bleeding rates. RESULTS: Initial hemostasis was achieved in 51 patients treated with combination therapy and 49 patients with epinephrine injection therapy (98% vs 92%, P = .18). Bleeding recurred in 2 patients in the combination therapy group and 11 patients in the epinephrine injection group (3.8% vs 21%, P = .008). Among the patients with rebleeding, repeated combination therapy was more effective than repeated injection therapy in achieving permanent hemostasis (100% vs 33%, P = .02). No patient required an emergency operation in the combination therapy group. However, 5 patients in the epinephrine injection group underwent emergency surgery to arrest bleeding (0% vs 9%, P = .023). LIMITATIONS: Treatment outcome of endoscopic hemoclip therapy is related to the techniques of endoscopists. CONCLUSION: Endoscopic combination therapy is superior to epinephrine injection alone in the treatment of high-risk bleeding ulcers.

Aged↗

PubMed2004

IL-12 cDNA direct injection: antimetastatic effect from a single injection in a murine hepatic metastases model.

BACKGROUND: Interleukin 12 (IL-12) gene therapy is an effective antitumor agent in local and metastatic murine tumor models. We sought to evaluate the antimetastatic effect of IL-12 cDNA in a liver metastases model. MATERIALS AND METHODS: A liver metastases model was induced by creating a "primary" splenic tumor through inoculation of 1 x 10(5) TS/A adenocarcinoma cells directly into the inferior pole of the spleen in female BALB/c mice. On day 4, 50 microg of IL-12 cDNA or control plasmid DNA was injected into splenic tumor, followed by splenectomy on day 8. Mice were sacrificed on day 25 to assess liver tumor burden. IL-12 mRNA and mIL-12 and IFN-gamma protein levels were assessed after IL-12 injection. Peripheral blood CD4+, CD8+, and NK cells were quantified on day 14 using FACS. To determine the significance of site of cytokine DNA injection, IL-12 cDNA was injected on day 4 into splenic tumor or into the non-involved spleen after isolation of the inferior and superior portions of the spleen, respectively, with surgical clips. Splenectomy was performed on day 8 and sacrifice was performed on day 25. RESULTS: IL-12 mRNA was detected in the liver 8 h after injection, with a peak at 24 h. After splenic injection, protein levels of IL-12 and IFN-gamma were detectable in the liver and spleen 24 h after treatment. IL-12 and IFN-gamma were not detectable in control animals. In the peripheral blood, there was a marked increase in NK cells (13% of total lymphocytes versus 4%, control) and in the CD4+/CD8+ ratio (5.5 versus 1.9). At day 25, there was a marked antimetastatic effect after IL-12 injection into either splenic tumor [liver:body weight, 6.2 versus 10.9 (control), P = 0.007] or non-involved spleen (6.8 g versus 10.7 g, P = 0.005). There was no difference in the antimetastatic effect between animals injected into splenic tumor or non-involved spleen (P = 0.3). CONCLUSION: Injection with a single dose of IL-12 cDNA into splenic tumor or non-involved spleen resulted in a profound antimetastatic effect. Splenic IL-12 injection results in mRNA expression in the liver, protein expression in the liver and spleen, and a marked increase in NK cells and the CD4+/CD8+ ratio in peripheral blood.

Adjuvants, Immunologic↗

PubMed2004

Injection pain and postinjection pain of the anterior middle superior alveolar injection administered with the Wand or conventional syringe.

OBJECTIVE: The purpose of this prospective, randomized, blinded study was to compare the pain of injection and post-injection pain of the AMSA injection using the computer-assisted Wand Plus injection system versus a conventional syringe. STUDY DESIGN: Using a crossover design, 40 subjects randomly received 2 blinded AMSA injections using the Wand Plus system and a conventional syringe, at 2 separate appointments. The AMSA injection site was centered halfway between the midpalatine raphe and gingival margin of the first and second premolars. The pain of needle insertion, anesthetic solution deposition pain, and postinjection pain were recorded on a Heft-Parker VAS for the 2 AMSA injections. RESULTS: For needle insertion, 38% of the subjects had moderate/severe pain with the Wand Plus((R)) and 34% moderate/severe pain with the conventional syringe, with no significant difference between techniques. There was a significant difference for solution deposition pain, with the conventional syringe causing more moderate/severe pain (42% conventional vs. 25% for the Wand Plus. Regarding postinjection pain, after numbness wore off there was no significant difference between the Wand Plus injection technique (0% moderate pain) and the conventional syringe technique (8% moderate pain). Postinjection, approximately 8% to 10% of the subjects experienced slight palatal swelling and 2% experienced temporary numbness. These problems resolved quickly and were considered minor. CONCLUSIONS: The AMSA injection, using the Wand Plus, resulted in similar pain ratings for needle insertion as the conventional syringe but statistically lower pain ratings upon anesthetic solution deposition. However, the AMSA, using either the Wand Plus or a conventional syringe, has the potential to be a painful injection. We found the incidence of postinjection pain and sequelae was low with both techniques.

Adult↗

PubMed1999

Treatment of intracorporeal injection nonresponse with sildenafil alone or in combination with triple agent intracorporeal injection therapy.

PURPOSE: We assess the efficacy of sildenafil as salvage therapy for intracorporeal injection therapy nonresponse. MATERIALS AND METHODS: The study group comprised 93 patients with a mean age of 53.6 years (range 24 to 77) with chronic erectile dysfunction. In all cases a home trial of intracavernosal injection of high dose alprostadil and triple agent intracavernosal injection therapy had failed. Patients were treated with sildenafil citrate alone or in combination with intracavernosal injection therapy. RESULTS: The etiology of erectile dysfunction was arteriogenic in 29 cases, cavernosal venous leakage in 36, mixed vasculogenic in 24, psychogenic in 3 and post-priapism intracavernous fibrosis in 1. Of the 32 sildenafil responders (34% of the study group) 30 required 100 and 2 required 50 mg. The 29 sildenafil intracavernosal injection (combined therapy) responders (31% of the study group) required 100 mg. sildenafil. There were 32 nonresponders (34% of the study group). Mean International Index of Erectile Function questions 3 and 4 scores were 1.7 and 1.5 at baseline, 2.3 and 1.9 with intracavernosal injection, 4.6 and 42.2 with sildenafil, and 4.1 and 4.10 with combined therapy, respectively. Of the 93 patients 29 (31%) treated with intracavernosal injection reported adverse effects, including penile pain in 27, dizziness in 5 and headache in 2. Of the patients treated with sildenafil 34 (37%) reported side effects, including headache in 30, facial flushing in 25, dyspepsia in 12, nasal congestion in 9, dizziness in 5 and visual disturbances in 1. Of the 41 patients given combined therapy 20 (49%) reported adverse effects, including penile pain in 15, headache in 15, facial flushing in 12, dyspepsia in 7, nasal congestion in 3, dizziness in 12 and syncope in 1. CONCLUSIONS: Sildenafil alone or sildenafil plus intracavernosal injection is effective salvage therapy for intracavernosal injection nonresponse. Sildenafil in combination with intracavernosal injection is associated with a 33% incidence of adverse effects, including a 20% incidence of dizziness.

Adult↗

PubMed2000

Dexamethasone concentration in the subretinal fluid after a subconjunctival injection, a peribulbar injection, or an oral dose.

PURPOSE: To determine dexamethasone concentrations in the subretinal fluid of patients after a peribulbar injection, a subconjunctival injection, or an oral dose of dexamethasone and to compare the results with those of previous similar studies of dexamethasone concentrations in the vitreous. DESIGN: Prospective, nonrandomized, comparative trial. PARTICIPANTS: One hundred forty-eight patients with a rhegmatogenous retinal detachment. METHODS: Fifty patients received a peribulbar injection of 5 mg dexamethasone disodium phosphate, 49 received a subconjunctival injection of 2.5 mg dexamethasone disodium phosphate, and 49 received an oral dose of 7. 5 mg dexamethasone at various time intervals before surgery. At the time of surgery, a subretinal fluid sample was taken from each patient. MAIN OUTCOME MEASURES: The dexamethasone concentration in the subretinal fluid measured by radioimmunoassay. RESULTS: The estimated maximum dexamethasone concentrations in the subretinal fluid after the peribulbar injection, the subconjunctival injection, and the oral dose were, respectively, 82.2 ng/ml (standard error, 17. 6), 359 ng/ml (standard error, 80.2), and 12.3 ng/ml (standard error, 1.61). Corrected for dose, the maximum dexamethasone concentrations after subconjunctival injection and peribulbar injection were, respectively, 120 (95% confidence interval, 54/180) and 13 (95% confidence interval, 6.8/20) times greater than after oral administration. CONCLUSIONS: A subconjunctival injection of dexamethasone disodium phosphate is more effective in delivering dexamethasone into the subretinal fluid of patients with a rhegmatogenous retinal detachment compared with peribulbar injection or oral administration. The subretinal dexamethasone concentrations were higher than concentrations measured in the vitreous in previous studies with a similar setup after all three delivery methods.

Administration, Oral↗

PubMed2001

Pumping injection of sodium hyaluronate for patients with non-reducing disc displacement of the temporomandibular joint: two year follow-up.

Objectives: The purpose of the present study was to examine the long-term effect of pumping injection of sodium hyaluronate into the TMJ in patients with non-reducing disc displacement. Patients: Sixty patients with non-reducing disc displacement underwent pumping injection of sodium hyaluronate (pumping group). Seventy-six patients with non-reducing disc displacements were observed without any active treatment (observation group). Study design: In both patient groups clinical signs and symptoms were observed periodically for 2 years. Variables such as age, range of maximum mouth opening, angle of posterior slope of the articular eminence and degenerative bony changes of the condyle at the initial visit were also examined. Cox hazards analysis was applied to examine the clinical outcome for such variables in addition to the results of pumping injection of sodium hyaluronate. Results: Pumping injection of sodium hyaluronate seemed to have a favourable effect when compared with the control group (untreated) (p=0.0002). However, the four background variables mentioned could not be explained as predictors of outcome. Conclusion: Pumping injection of sodium hyaluronate seems to be effective for non-reducing disc displacement of the temporomandibular joint. Copyright 2001 European Association for Cranio-Maxillofacial Surgery.

Journal Article↗

PubMed1958

Effect of secondary injections of antigen upon the retention in liver of a primary injection.

The retention of antigen in rabbit liver tissue, resulting from a primary intravenous injection, is influenced by immunization brought about by subsequent intravenous injections of the same antigen. In rabbits given a single primary intravenous injection of radioactive antigen, the retention of radioactivity in liver tissue, after a period of 21 days, was greater than when the primary injection was followed by secondary injections of the same, but non-radioactive antigen. The results were similar for both S(35)-azohemocyanin and S(35)-azo-bovine-serum-albumin, except the hemocyanin was retained to a greater extent than the albumin. There was very little if any correlation between the number of secondary injections and retention of the initial injection. Quantitative antibody nitrogen data, obtained for the serum of each rabbit showed, in general, an inverse relationship between circulating antibody and radioactivity retained, i.e. the higher the circulating antibody titer, the lower the retention of radioactivity in liver tissue. Passively administered homologous antibody did not produce a change in the retention of the primary injection of antigen nor did secondary injections of a heterologous native protein injected according to the same immunization schedule as the homologous azoprotein. From these results it may be concluded that an intracellular antibody-forming activity influences the loss (or retention) of antigen deposited in liver tissue and that the mechanism is immunologically specific.

Animals↗

PubMed2006

Randomized comparison of the single-injection volar subcutaneous block and the two-injection dorsal block for digital anesthesia.

BACKGROUND: Two commonly used methods of digital nerve block with local anesthetic are the two-injection dorsal technique and the single-injection volar subcutaneous technique. The authors compared these two digital block techniques with respect to local anesthetic injection pain and recipient preference of anesthetic technique. METHODS: Twenty-seven volunteers had the long finger of each hand injected with 2% lidocaine with 1:100,000 epinephrine. The two-injection dorsal method was used on one long finger and the other long finger received the volar single-injection technique. Volunteers completed a pain scale for each block and were then asked which technique they would prefer. The area of anesthetic skin was assessed in each finger by pinprick testing, and photographs were taken. RESULTS: Although there was a lower pain score for the volar single-injection block, the difference in pain scores between the two techniques was not statistically significant. However, 22 of the 27 subjects indicated that they would select the volar over the dorsal block if a future block was required, and this preference for the volar block was statistically significant. CONCLUSIONS: Although the difference in pain scores between the two techniques was not statistically significant, volunteers who received both blocks would prefer the volar single-injection subcutaneous block if given a choice. Therefore, the single-injection volar subcutaneous block is recommended as the technique of choice for anesthesia of the digit, except in patients for whom anesthesia over the dorsum of the proximal phalanx is required. These patients may prefer a supplementary dorsal nerve block or a traditional two-injection block.

Adult↗

PubMed1978

Longitudinal spread of intraneurally injected local anesthetics. An experimental study of the initial neural distribution following intraneural injections.

Unexpected spinal anesthesia, occurring after peripheral nerve blocks close to the spine, may be caused by a centripetal spread of the local anesthetic along the injected nerve to the spinal cord. In order to analyze the pathway of such a spread, a radioactive local anesthetic mixed with a fluorescent dye was injected into difrerent compartments of the rabbit sciatic nerve, and the early distribution of these tracers was studied by scintillation counting and fluorescence microscopy. Epineurial (extrafascicular) injections were of low injection pressure (25-60 mmHg) (3.3-7.9 kPa) and limited spread, while endoneurial (intrafascicular) injections reached higher pressures (300-750 mmHg) (39.9-99.7 kPa) and caused a rapid spread over long distances within the fascicle. The sacral plexus seemed difficult to pass. However, 20% of endoneurial injections reached the spinal cord, where the injectate primarily spread in the thin subpial space. Our experimental findings suggest that intraneural injections of local anesthetics are responsible for the reported cases of unexpected spinal anesthesia due to inadvertent intrafascicular spread. Although intrafascicular injections are rarely made, we recommend that intraneural injections of local anesthetics or other solutions close to the spine should be avoided, as they may cause unexpected spinal anesthesia or lesion of the cord.

Anesthesia, Spinal↗

PubMed1985

Local tissue damage after intramuscular injections in rabbits and pigs: quantitation by determination of creatine kinase activity at injection sites.

The creatine kinase (CK) method, which is based on difference in CK activity at injection sites and in control tissue, was used for quantitation of local tissue damage after intramuscular injection of varying volumes and preparations in rabbits and pigs. Injections were given in the central part of the longissimus dorsi muscle. Three days after the injections the animals were killed and the arbitrary amounts of tissue without CK were calculated from the CK activity in muscle tissue at the injection sites and in control tissue. Determination of tissue damage by the CK method was in good agreement with macroscopic and microscopic changes, whether a well demarcated necrotic area or little or no necrosis was found at the injection site. Tissue damage was proportional to injection volumes between 0.25 and 1 ml in rabbits and 0.5 and 3 ml in pigs. In rabbits tissue damage per injected ml was found to be more than twice the damage seen in pigs. It is concluded that the CK method is a reliable method for quantitation of local tissue damage after intramuscular injections and that injection of even small volumes of 0.25-0.5 ml in the longissimus dorsi muscle of rabbits is a sensitive test of the local toxicity of drugs.

Animals↗