Method Of Anesthesia Delivery Research Articles

A case report of personal exposures to isoflurane during animal anesthesia procedures

ABSTRACTThe purpose of this study was to compare personal exposures to isoflurane from participants' breathing zone samples during animal anesthesia procedures by the method of anesthetic gas delivery and the waste anesthetic gas (WAG) control method utilized. WAG control methods included passive scavenging using charcoal canisters, active scavenging using a building vacuum system, and various local exhaust ventilation systems such as laboratory fume hoods and capture hoods. Methods of anesthesia delivery included induction chambers, face masks (also known as nose cones), and intubation. Personal breathing zone samples were collected using 3M 3520 Organic Vapor Diffusion Monitors and submitted to an International Organization for Standardization (ISO) 17025 accredited laboratory for analysis.When using face masks and induction chambers as the method of anesthesia delivery, local exhaust ventilation systems were found to be the best WAG control method to mitigate personal exposures to isoflurane. Personal exposures to isoflurane were well-controlled when animals were intubated, regardless of whether passive scavenging with an adsorptive charcoal canister or active scavenging with a building vacuum system was used. Personal exposures to isoflurane were highest when induction chambers and face masks were used for anesthesia delivery, and passive scavenging with adsorptive charcoal canisters were used as the control method. This study served to identify best practice WAG control methods for research and veterinary procedures that involve isoflurane anesthesia.

Continuous Transversus Abdominis Plane Nerve Blocks: Does Varying Local Anesthetic Delivery Method—Automatic Repeated Bolus Versus Continuous Basal Infusion—Influence the Extent of Sensation to Cold?: A Randomized, Triple-Masked, Crossover Study in Volunteers

BACKGROUND: It remains unknown whether continuous or scheduled intermittent bolus local anesthetic administration is preferable for transversus abdominis plane (TAP) catheters. We therefore tested the hypothesis that when using TAP catheters, providing local anesthetic in repeated bolus doses increases the cephalad-caudad cutaneous effects compared with a basal-only infusion. METHODS: Bilateral TAP catheters (posterior approach) were inserted in 24 healthy volunteers followed by ropivacaine 2 mg/mL administration for a total of 6 hours. The right side was randomly assigned to either a basal infusion (8 mL/h) or bolus doses (24 mL administered every 3 hours for a total of 2 bolus doses) in a double-masked manner. The left side received the alternate treatment. The primary end point was the extent of sensory deficit as measured by cool roller along the axillary line at hour 6 (6 hours after the local anesthetic administration was initiated). Secondary end points included the extent of sensory deficit as measured by cool roller and Von Frey filaments along the axillary line and along a transverse line at the level of the anterior superior iliac spine at hours 0 to 6. RESULTS: Although there were statistically significant differences between treatments within the earlier part of the administration period, by hour 6 the difference in extent of sensory deficit to cold failed to reach statistical significance along the axillary line (mean = 0.9 cm; SD = 6.8; 95% confidence interval –2.0 to 3.8; P = .515) and transverse line (mean = 2.5 cm; SD = 10.1; 95% confidence interval –1.8 to 6.8; P = .244). Although the difference between treatments was statistically significant at various early time points for the horizontal, vertical, and estimated area measurements of both cold and mechanical pressure sensory deficits, no comparison remained statistically significant by hour 6. CONCLUSIONS: No evidence was found in this study involving healthy volunteers to support the hypothesis that changing the local anesthetic administration technique (continuous basal versus hourly bolus) when using ropivacaine 0.2% and TAP catheters at 8 mL/h and 24 mL every 3 hours significantly influences the cutaneous effects after 6 hours of administration. Additional research is required to determine whether changing variables (eg, local anesthetic concentration, basal infusion rate, bolus dose volume, and/or interval) would provide different results.

Comparison of local anesthetic effect of lidocaine by jet injection vs needle infiltration in lumbar puncture

BackgroundUsual routes of drug administration are often painful and invasive. Nowadays, using jet injection has been introduced successfully, as a noninvasive and painless method of anesthetic delivery in performing different procedures. ObjectiveThe objective of the study is to compare the local anesthetic effect of lidocaine by jet injection vs needle infiltration in performing lumbar puncture in the emergency department (ED). MethodsA randomized single-blind controlled study was performed in 65 patients needing lumbar puncture recruited from the ED from July to November 2014. We enrolled 44 patients and excluded 21 patients by the exclusion criteria. Local lidocaine was delivered in 1 group by jet injector (group B), whereas in the other group conventional method, needle infiltration was used (group A). In both groups, intravenous midazolam 1 mg was administered as an anxiolytic drug before the procedure. Patients' pain score (visual analog scale [VAS]) from 0 to 10 was recorded both during drug delivery and performing the procedure itself. The observer who collected patients' data and fulfill the questionnaire was blinded to the study. ResultsDuring lidocaine injection, the mean ± SD VAS score was 5.27 ± 1.77 in group A and 2.95 ± 1.81 in group B (mean difference, 2.31; 95% confidence interval, 1.22-3.41) (P= .000). During performing the procedure, the mean ± SD VAS score in groups A and B was 3.77 ± 1.77 vs 2.18 ± 1.50 (mean difference, 1.59; 95% confidence interval, 0.59-2.58) (P= .003). ConclusionsInjecting lidocaine by jet injector is less painful than infiltrating it by needle and syringe.

Painless delivery: Yes or no?

Contemporary obstetrics aims to achieve painless delivery, whereby the life of the mother or fetus would not be compromised. Epidural analgesia is nowadays considered to be the method of choice for the labor pain relief. The aim of this paper is to provide an overview of the basic principles and techniques of performing epidural analgesia, its specificities for women in labor, its effects on the mother and fetus, as well as the dilemmas that accompany this method. The specificities of epidural anesthesia in pregnant women, such as soft tissue edema, increased weight, changes in texture ligaments, lumbar lordosis and engorgement of epidural veins, make it more difficult to perform the epidural block in pregnancy. The most important misconception is the influence of epidural analgesia on operative or instrumental delivery rate. Low concentrations of local anesthetic in combination with small doses of opioids, together with active management of labor by an obstetrician, would lead to increased spontaneous delivery rate. Epidural analgesia is currently the most effective and the safest method of anesthesia delivery.

Ultrasound-guided continuous interscalene block: the influence of local anesthetic delivery method (automated bolus versus continuous infusion) on postoperative analgesia after shoulder surgery

Ultrasound-guided continuous interscalene block: the influence of local anesthetic delivery method (automated bolus versus continuous infusion) on postoperative analgesia after shoulder surgery

Pain Scores and Local Anesthesia for Transrectal Ultrasound-Guided Prostate Biopsy in Patients with Anorectal Pathologies

The aim of the present randomized study was to evaluate the efficacy of lidocaine gel compared with dimethylsulfoxide (DMSO) with lidocaine for transrectal ultrasonography (TRUS)-guided prostate biopsy in patients with anorectal pathologies. Sixty-two patients were randomly divided into two equal groups. Group 1 was given 10 mL of 2% lidocaine gel intrarectally 10 minutes before the biopsy. Group 2 was given 10 mL of intrarectal 40% DMSO with an amount of lidocaine equal to that in the lidocaine gel 10 minutes before the procedure. The degree of pain was rated by patients using a 10-point visual analog scale. The pain scores for probe insertion were significantly lower for group 2 (3.15 +/- 1.41) than for group 1 (4.58 +/- 160) (P = 0.01). No significant differences were found between the pain scores of the two groups for biopsy-needle insertion (P = 0.62). Dimethylsulfoxide with lidocaine instilled into the rectum is a simple, safe, rapid-acting, and effective method of anesthesia delivery before TRUS-guided prostate biopsy in patients with anorectal pathologies.

Sugammadex: a novel neuromuscular blocker binding agent

Sugammadex is a novel drug that binds selected neuromuscular blocking drugs and prevents them from acting at the neuromuscular junction. Due to its rapid onset and relative lack of side effects, this drug promises to change the method of anesthesia delivery. This review summarizes the literature on the drug and addresses some of the potential changes that it may bring. Currently in phase III clinical trials, sugammadex has been shown to be safe and efficacious in small animal and human study groups and is now undergoing wider clinical testing to secure FDA approval for general use. Sugammadex binds neuromuscular blocking drugs and encapsulates them, making cholinesterase inhibitors unnecessary. Its rapid reversal of blockade makes it possible to keep patients profoundly muscle relaxed until drapes come down and it can enable a rapid return to spontaneous ventilation in a 'cannot intubate, cannot ventilate' situation. Costs and date of availability have yet to be determined.

Computerized local dental anesthetic systems: patient and dentist satisfaction

A computer controlled dental anesthetic delivery system was studied with the Objective of evaluating and comparing the unit to the traditional method of anesthetic delivery. The research design and Method of study involved the use of trained dentists who used both types of delivery systems on patients seen during their routine practice of dentistry. After the dental appointment was finished each dentist completed a survey concerning the injection. Patients completed a survey before the injection concerning their previous anesthetic experiences and completed another survey at the end of the dental appointment concerning the injection they had just received. Statistical analyses yielded Results showing the two methods were rated very similarly by both patients and dentists. Conclusions resulting from the study are that computer controlled dental anesthetic injections and traditional anesthetic injections were accepted equally well by both dentists and patients.

LOCAL ANESTHESIA FOR ULTRASOUND GUIDED PROSTATE BIOPSY: A PROSPECTIVE RANDOMIZED TRIAL COMPARING 2 METHODS

Since the introduction of prostate specific antigen (PSA) screening, asymptomatic men often undergo transrectal ultrasound guided prostate biopsy. This procedure may cause significant discomfort, which may limit the number of biopsies. We performed a randomized prospective study to compare periprostatic infiltration with 1% lidocaine with intrarectal instillation of 2% lidocaine gel before prostate biopsy. From October 1999 to July 2000, 150 men underwent prostate biopsy at the Miami Veterans Administration and Jackson Memorial Hospital. Experienced senior residents performed all biopsies. Patients were randomized into 2 groups depending on the method of anesthetic delivery. A visual analog scale was used to assess the pain score. Statistical analysis of pain scores was performed using the Student t test. Ultrasound guided prostate biopsy was done in 150 cases. There was a statistical difference in the mean pain score after periprostatic infiltration and intrarectal instillation (2.4 versus 3.7, p = 0.00002) with patients receiving periprostatic infiltration reporting significantly less pain. Men should have the opportunity to receive local anesthesia before ultrasound guided prostate biopsy with the goal of decreasing the discomfort associated with this procedure. Our prospective randomized study indicates that ultrasound guided periprostatic nerve block with 1% lidocaine provides anesthesia superior to the intrarectal placement of lidocaine gel.

Lidocaine via lontophoresis in laceration repair: A preliminary safety study

Iontophoresis is a painless technique for topical anesthesia that uses an electric field to drive charged ions across an epithelial surface. The safety of this technique for laceration repair has never been demonstrated. The purpose of this study was to investigate the effect of iontophoretic fields on rapidly proliferating cells involved in laceration wound healing. The study was a prospective single-blinded animal study using a guinea pig model. Twelve guinea pigs each received four induced, uncontaminated lacerations. Each guinea pig was randomly assigned to 1 of 3 groups (4 guinea pigs in each group). One group received lidocaine via iontophoresis, one group received injected lidocaine, and one group received half iontophoresis and half injected lidocaine. After anesthetic treatment, wounds were then repaired in a standard fashion. The wounds were examined grossly on a daily basis and on day 10 the incised skin containing the laceration was examined by a pathologist blinded to the treatment group. A total of 48 wounds were assessed for wound healing, 24 of which received lidocaine via iontophoresis and 24 lidocaine via injection. The power of the study to determine a 40% difference between the two groups was 0.8. There was significantly more granuloma and granulation tissue formation in the iontophoresis group than in the injected lidocaine control group ( P = .0004, Fisher's exact test). There were no statistically significant differences in degree of inflammation between the two groups (lidocaine via injection v lidocaine via iontophoresis) measured by amount of dermal fibrosis ( P = .14, Fisher's exact test), giant cell formation ( P = .21, Fisher's exact test), and presence of acute and/or chronic inflammation ( P = .17, Wilcoxon's rank sum test). Wound healing proceeded normally with 100% in both groups having normal scar formation and healing at day 10. In conclusion, iontophoresis appears to be a safe method of anesthesia delivery in this guinea pig model with lacerations. Increased granuloma and granulation tissue formation may indicate an enhancement of wound healing via iontophoresis.

The effects of lidocaine anesthesia via lontophoresis on laceration wound healing in a guinea pig model

0 The Effects of tidocaine Anesthesia via Iontophoresis on Laceration Wound Healing in a Guinea Pig Model AA Ernst, J Pomerantz, TG Nick, M Landry, J Limbaugh/Louisiana State University Departments of Medicine and Pathology, Section of Emergency Medicine; University of Mississippi School of Allied Health Professions Study background: Iontophoresis is a painless technique for topical anesthesia that uses an electric field to drive charged ions across an epithelial surface. Although it has been used successfully for intact skin, the safety of this technique for laceration repair has never been demonstrated. Study ol~lective: To investigate the effect of iontophoretic fields on rapidly proliferating cells involved in healing of laceration wounds. Design: Prospective, single-blinded animal study using a guinea pig model. Participants: Twelve adult albino guinea pigs. Intervention: Each of the 12 guinea pigs received four induced uncontaminated lacerations. Guinea pigs were nmdomized to groups receiving treatment with lidocaine via iontophoresis, injected lidocainc or half treatment and half control. Aftcr anesthelic treatment, wounds were repaired in as tan dard fashion. The wounds were examined grossly on a daily basis, and on the tenth day the incised skin containing the laceration was examined by a pat hologist blinded to treatment group Measurements and main resuhs: Forty-eight wounds were assessed for wound healing--24 receivcd lidocame via iontophoresis, and 24 received lidocaine via injection. No clinical or histologic evidence of int~:ction or necrosis was present in any wound. The power of the study to determine a 40% difference between the two groups was 0.8. There was significantly more gl-anu[oma and granulation tissue formation in the iontophoresis group than in the irtiected lidocaine control group (P = .0004 Fisher's exact test). -I'herc was no statistically significant differences in the degree of inflammation between the two groups as measured by amount of dermal fibrosis (P =. [4 Fisher's exact test), giant cell Iormation (P = .21, Fisher's exact test), and presence of acute and/or chronic inl]ammation (P = .17, Wilcoxon rank-sum test). Wound healing proceeded normally with 100% in both groups having normal scar formauon and healing at ten days. Conc]usion: lontophoresis appears to be a safe method of anesthesia delivery in this guinea pig model with lacerations. Increased granuloma and granulation tissue formation may indicate an enhancement of wound healing via ionmphoresis. Further study of the safety and efficacy of anesthesia dehvery via this method is needed.

Exposure of hospital operating room personnel to potentially harmful environmental agents.

Epidemiologic studies of risk to reproductive health arising from the operating room environment have been inconclusive and lack quantitative exposure information. This study was undertaken to quantify exposure of operating room (OR) personnel to anesthetic agents, x-radiation, methyl methacrylate, and ethylene oxide and to determine how exposure varies with different operating room factors. Exposures of anesthetists and nurses to these agents were determined in selected operating rooms over three consecutive days. Each subject was asked to wear an x-radiation dosimeter for 1 month. Exposure to anesthetic agents was found to be influenced by the age of the OR facility, type of surgical service, number of procedures carried out during the day, type of anesthetic circuitry, and method of anesthesia delivery. Anesthetists were found to have significantly greater exposures than OR nurses. Exposure of OR personnel to ethylene oxide, methyl methacrylate, and x-radiation were well within existing standards. Exposure of anesthetists and nurses to anesthetic agents, at times, was in excess of Ontario exposure guidelines, despite improvements in the control of anesthetic pollution.

Iontophoresis versus subcutaneous injection: a comparison of two methods of local anesthesia delivery in children

The relative efficacy of local lidocaine anesthesia administered by subcutaneous injection and by iontophoresis was studied in 13 pediatric renal dialysis patients (ages 11–19 years; mean age 15.8 years). Each patient served as his own control at 3 assessment periods. Each type of anesthetic delivery method was administered to either of 2 fistula sites. Patients used visual analogue scales to rate pain, anxiety, and satisfaction for each method. Behavioral observations were made by an observer and a nurse. Paired sample t tests were used to compare the 2 drug delivery methods for patient, observer, and nurse ratings across assessment periods. There were no significant differences between methods for ratings of anxiety before or during the procedure. The injection of lidocaine was rated as more painful by the observer and nurse (with a trend for patients) than the use of iontophoresis. But, the patients and nurse rated the injection method as more effective. Iontophoresis was never rated as superior to the injection method, even after turning over control of drug delivery by iontophoresis to the patient (sessions 2 and 3). Patients were more satisfied with iontophoresis at session 2 when they took over control, but lost enthusiasm by session 3. Three subjects withdrew from the study due to cutaneous burns and prolonged anesthesia delivery time with iontophoresis. Iontophoresis appears to be effective in reducing the pain of dialysis needle insertion but requires further investigation before it can be considered a viable alternative to subcutaneous injection.