Use of the Schelin Catheter for transurethral intraprostatic anesthesia prior to Rezum treatment.

Minimally invasive surgery techniques (MIST) have become newly adopted in urological care.  Given this, new analgesic techniques are important in optimizing patient outcomes and resource management. Rezum treatment (RT) for BPH has emerged as a new MIST with excellent patient outcomes, including improving quality of life (QoL) and International Prostate Symptom Scores (IPSSs), while also preserving sexual function.  Currently, the standard analgesic approach for RT involves a peri-prostatic nerve block (PNB) using a transrectal ultrasound (TRUS) or systemic sedation anesthesia.  The TRUS approach is invasive, uncomfortable, and holds a risk of infection.  Additionally, alternative methods such as, inhaled methoxyflurane (Penthrox), nitric oxide, general anesthesia, as well as intravenous (IV) sedation pose safety risks or mandate the presence of an anesthesiology team.  Transurethral intraprostatic anesthesia (TUIA) using the Schelin Catheter (ProstaLund, Lund, Sweden) (SC) provides a new, non-invasive, and efficient technique for out-patient, office based Rezum procedures.  Through local administration of an analgesic around the prostate base, the SC has been shown to reduce pain, procedure times, and bleeding during MISTs.  Herein, we evaluated the analgesic efficacy of TUIA via the SC in a cohort of 10 patients undergoing in-patient RT for BPH.

A narrative review on pain control interventions for non-surgical pleural procedures.

Pleural diseases are common and frequently result in disabling symptoms, impaired health-related quality of life and hospitalisation. Both diagnosis and management often require pleural procedures and despite a variety of pain control strategies available for clinicians to employ, many procedures are still complicated by pain and discomfort. This can interfere with procedure success and can limit patient satisfaction. This review examines the evidence for pain control strategies for people undergoing non-surgical pleural procedures. A systematic literature search was undertaken to identify published studies examining different pain control strategies including pharmacological (sedatives, paravertebral blocks, erector spinae blocks, intrapleural anaesthesia, epidural anaesthesia, local anaesthetic, methoxyflurane, non-steroidal anti-inflammatory drugs [NSAIDs], opioids) and non-pharmacological measures (transcutaneous electric nerve stimulation [TENS], cold application and changes to the intervention or technique). Current literature is limited by heterogeneous study design, small participant numbers and use of different endpoints. Strategies that were more effective than placebo or standard care at improving pain included intrapleural local anaesthesia, paravertebral blocks, NSAIDs, small-bore intercostal catheters (ICC), cold application and TENS. Inhaled methoxyflurane, thoracic epidural anaesthesia and erector spinae blocks may also be useful approaches but require further evaluation to determine their roles in routine non-surgical pleural procedures. Future research should utilise reliable and repeatable study designs and reach consensus in endpoints to allow comparability between findings and thus provide the evidence-base to achieve standardisation of pain management approaches.

'Pain-free TRUS B': a phase 3 double-blind placebo-controlled randomized trial of methoxyflurane with periprostatic local anaesthesia to reduce the discomfort of transrectal ultrasonography-guided prostate biopsy (ANZUP 1501).

OBJECTIVE: To determine whether the addition of inhaled methoxyflurane to periprostatic infiltration of local anaesthetic (PILA) during transrectal ultrasonography-guided prostate biopsies (TRUSBs) improved pain and other aspects of the experience. PATIENTS AND METHODS: We conducted a multicentre, placebo-controlled, double-blind, randomized phase 3 trial, involving 420 men undergoing their first TRUSB. The intervention was PILA plus a patient-controlled device containing either 3 mL methoxyflurane, or 3 mL 0.9% saline plus one drop of methoxyflurane to preserve blinding. The primary outcome was the pain score (0-10) reported by the participant after 15 min. Secondary outcomes included ratings of other aspects of the biopsy experience, willingness to undergo future biopsies, urologists' ratings, biopsy completion, and adverse events. RESULTS: The mean (SE) pain scores 15 min after TRUSB were 2.51 (0.22) in those assigned methoxyflurane vs 2.82 (0.22) for placebo (difference 0.31, 95% confidence interval [CI] -0.75 to 0.14; P = 0.18). Methoxyflurane was associated with better scores for discomfort (difference -0.48, 95% CI -0.92 to -0.03; P = 0.035, adjusted [adj.] P = 0.076), whole experience (difference -0.50, 95% CI -0.92 to -0.08; P = 0.021, adj. P = 0.053), and willingness to undergo repeat biopsies (odds ratio 1.67, 95% CI 1.12-2.49; P = 0.01) than placebo. Methoxyflurane resulted in higher scores for drowsiness (difference +1.64, 95% CI 1.21-2.07; P < 0.001, adj. P < 0.001) and dizziness (difference +1.78, 95% CI 1.31-2.24; P < 0.001, adj. P < 0.001) than placebo. There was no significant difference in the number of ≥ grade 3 adverse events. CONCLUSIONS: We found no evidence that methoxyflurane improved pain scores at 15 min, however, improvements were seen in patient-reported discomfort, overall experience, and willingness to undergo repeat biopsies.

Multiple criteria decision analysis approach to consider therapeutic innovations in the emergency department: The methoxyflurane organizational impact in acute trauma pain.

BACKGROUND: Acute trauma pain is poorly managed in the emergency department (ED). The reasons are partly organizational: ED crowding and rare trauma care pathways contribute to oligoanalgesia. Anticipating the organizational impact of an innovative care procedure might facilitate the decision-making process and help to optimize pain management. METHODS: We used a multiple criteria decision analysis (MCDA) approach to consider the organizational impact of methoxyflurane (self-administered) in the ED, introduced alone or supported by a trauma care pathway. A MCDA experiment was designed for this specific context, 8 experts in emergency trauma care pathways (leading physicians and pharmacists working in French urban tertiary hospitals) were recruited. The study involved four steps: (i) Selection of organizational criteria for evaluating the innovation's impact; (ii) assessment of the relative weight of each criterion; (iii) choice of appropriate scenarios for exploring the organizational impact of MEOX under various contexts; and (iv) software-assisted simulation based on pairwise comparisons of the scenarios. The final outcome measure was the expected overall organizational impact of methoxyflurane on a 0-to-100 scale (score >50: positive impact). RESULTS: Nine organizational criteria were selected. "Mean length of stay in the ED" was the most weighted. Methoxyflurane alone obtained 59 as a total score, with a putative positive impact for eight criteria, and a neutral effect on one. When a trauma care pathway was introduced concomitantly, the impact of methoxyflurane was greater overall (score: 75) and for each individual criterion. CONCLUSIONS: Our model highlighted the putative positive organizational impact of methoxyflurane in the ED-particularly when supported by a trauma care pathway-and the relevance of expert consensus in this particular pharmacoeconomic context. The MCDA approach could be extended to other research fields and healthcare challenges in emergency medicine.

Effect of electroacupuncture on blood pressure and adrenal nerve activity in anesthetized rats.

The neural mechanism underlying the effect of electroacupuncture (Ea) on arterial blood pressure (BP) and adrenal nerve activity (ANA) was investigated in anesthetized rats. Tsusanli (St-36) and Hoku (Li-4) were tested with combinations of two different frequencies (3 and 30 Hz) with various stimulation intensities of Ea. At Tsusanli, no effect was found, while at Hoku, an elevation of BP in parallel with ANA was elicited during Ea when the intensity was 5xT or higher. The pattern of the pressor response caused by the low frequency Ea (LFEa, 3 Hz) was a tonic one, while a phasic one was induced by the high frequency Ea (HFEa, 30 Hz). When both Hoku were simultaneously stimulated with the same frequency, the latency to reach the maximal effect was shortened. However, when two different frequencies were used instead, a response characterized by a combination of both phasic and tonic effect was obtained. In bilateral Ea with idential frequency but different onset time, the pressor effect elicited by the latter Ea showed no further increase during the stimulation period, however, when different frequencies were employed, each Ea elicited its own effect independently. The pressor effect elicited by Ea was abolished by regitine but not affected by adrenalectomy. It is concluded that a LFEa and a HFEa at Hoku with appropriate stimulation parameters can increase BP which is mainly due to potentiation of the sympathetic vasoconstrictor tone but via different central mechanisms.

Effects of halothane and methoxyflurane on the hypothalamic-pituitary-adrenal axis in rat.

Effects of acute exposure (2 h) to either 1.5% halothane or 0.5% methoxyflurane on chemical mediators of the hypothalamic-pituitary-adrenal (HPA) axis were evaluated in male Sprague-Dawley rats immediately after exposure, after the righting reflex (4 h), or 24 h postexposure. Effects of these anesthetics on hippocampal corticotropin releasing factor (CRF) were also evaluated. Methoxyflurane caused significant elevations in pituitary adrenocorticotropin hormone (ACTH)-like immunoreactivities in all three of the experiment's time groups, yet halothane failed to cause the same response immediately after exposure. Serum ACTH-like immunoreactivities were significantly elevated immediately after exposure to both anesthetics, but were not elevated at 4 and 24 h postexposure. Corticosterone (CORT)-like immunoreactivities were significantly elevated by halothane in all experimental groups, and in the 2- and 24-h groups following methoxyflurane exposure. Hippocampal CRF-like immunoreactivities remained unaffected by either anesthetic. Results indicate that a 2-h exposure to either halothane or methoxyflurane results in significant activation of the rat hypothalamic-pituitary-adrenal axis, and that the activation appears to be sustained over a 24-h period.

Long duration local anesthesia with lecithin-coated microdroplets of methoxyflurane: studies with rat skin.

Lecithin-coated microdroplets of methoxyflurane (MOF) are shown to produce local anesthesia of three- to six-day duration in the skin with a single intradermal injection in rats. Anesthesia was quantitated by elevation of the threshold (milliampere) for shock vocalization with intradermal electrodes. Intradermal injection of 0.1 ml 0.5% MOF gave moderate (2.1 mA) anesthesia of approximately three-day duration for a 10-12-mm diameter area, with no damage to the tissue. Higher concentrations gave six-day duration anesthesia at very high level (7 to 12 mA) anesthesia of three- to five-day duration with some damage to the tissue. At 4.4% MOF, ulcers formed in the center of the injection site with maximal dimensions of 1.3 mm (11-13% of the site diameter). Phenol, a widely used neurolytic agent, was tested as a control in the same concentration range. Phenol at 4.4% gave very high level (8 mA) anesthesia for longer than seven-day duration and caused formation of ulcers with maximal dimensions of 3.8 mm (31-38% of the site diameter). Analysis showed that MOF produced less damage than phenol for any given degree of anesthesia. Systemic toxicity and pharmacokinetic data are also presented. Phenol produced a hypothermic reaction and behavioral changes, whereas MOF was without systemic effect. The plasma concentrations of phenol were four to five times greater than those of MOF. These results suggest that MOF may have clinical advantages over phenol.

Long duration local anesthesia with lecithin-coated microdroplets of methoxyflurane: studies with human skin.

Lecithin-coated microdroplets of methoxyflurane (MOF) have been reported to produce local anesthesia of long duration in rats. The present study was conducted in two phases. The first phase was open label studies in two human volunteers aimed at determining the effective concentration of MOF in human skin. Over the concentration range of 0.3-2.4%, MOF produced local anesthesia to pinprick and cold stimuli within 15 seconds. The duration of the anesthesia effect of 2.4% MOF in the skin of the buttock, forearm and leg was five to eight days. Microdroplets containing isoflurane, a more volatile agent, gave an anesthetic effect that reversed within two to five hours. In the second phase of the study, the safety and efficacy of MOF were compared to phenol in placebo-controlled and blinded studies using indwelling stimulating electrodes. Phenol was destructive to skin at a concentration necessary to obtain a degree of local anesthesia comparable to MOF. The greater part of the anesthetic effect produced by phenol at this "toxic" concentration was transient (approximately one hour). In contrast to phenol, MOF produced an anesthetic effect lasting four to seven days without producing visible damage to skin. These results suggest that MOF is safer and more efficacious than phenol for producing long-lasting local anesthesia of human skin.

[Anesthesia in birds]. / Anästhesie beim Vogel.

Anaesthesia in birds is ordered by law and is also necessary for various operations and manipulations. Anaesthesia by injection of Ketamin, which in special cases may be combined with Diazepam, has been found useful. Anaesthesia by inhalation with Halothan, Methoxyfluran or Isofluran is the most careful method. Local anaesthesia has few indications.

Effects of Ginseng on the Metabolism of Enflurane and Methoxyflurane

Ginseng has been believed to be a powerful tonic by oriental people for a long time and is one of the most popular folk medicine in oriental countries. Intraperitoneal injection of ginseng into rats and mice has been reported to Increase the rates of hepatic RNA and protein synthesis, increase proliforation of rough RES of liver, and enhance alcohol metabolism. We have carried out a study to see the effects of red ginseng powder and extract on in vivo and in vitro metabolism of enflurane and methoxyflurane in male Fisher 344 rats. Red ginseng powder was dissolved in deionized water and dosed for two weeks ad libitum in rats. Hepatic microsomes were prepared and oxidative defluorination of enflurane and methoxyflurane were measured in vitro. Using red ginseng extract, studies were done of both acute and chronic treatment in rats. In chronic experiments, they were dosed with several dosages three times a day for three days; on the fourth day enflurane was administered i.p. and one hour later fluoride levels were mesured in plasma and hepatic microsomes were prepared for in vitro studies as above. In the acute experiment enflurane was administered intraperitoneally eighteen hours after single oral dosage of ginseng and plasma defluorination was measured. There were no statistically significant differences in hepatic microsomal cytochrome P-450 content or defluorination of enflurane and methoxyflurane between control and experimental groups using either red ginseng extract or powder. The results showed that ginseng ingestion did not affect the metabolism of enflurane and methoxyflurane.

Ultra-long-duration local anesthesia produced by injection of lecithin-coated methoxyflurane microdroplets.

This study was designed to evaluate a new drug delivery system. The authors undertook to determine if microdroplets prepared by encapsulating volatile anesthetics with a membrane of lecithin could be used for local anesthesia. Local anesthesia was determined by monitoring the response of the rat to tail clamping and electrical stimulation of the skin following the intradermal injection of the microdroplets. Microdroplets were prepared from isoflurane, enflurane, halothane, methoxyflurane, diethyl ether, chloroform, and heptane. Although all microdroplet preparations produced local anesthesia, only methoxyflurane microdroplets produced an ultra-long duration of local anesthesia (approximately 24 h). Further characterization of the methoxyflurane microdroplets revealed two important differences from conventional local anesthetics. First, the local anesthetic effect of methoxyflurane reached a plateau that did not change significantly for 20 h while the injection of lidocaine and bupivacaine resulted in a peak effect that returned to baseline within 1 and 3 h, respectively. Second, the anesthetic effect of methoxyflurane remained essentially localized to the site of injection, while the anesthetic effect of lidocaine and bupivacaine migrated 15 cm in less than 1 h. The toxicity and safety of methoxyflurane were evaluated. When administered over the dosage range 1-16% (v/v) intradermally, or by injections into muscle, or by repeat injections every 4 days for 16 days, all animals regained their pretreatment response to painful stimulations, and there was no evidence of gross injury to tissue. Deliberate intravenous injection of 0.8 ml of 6.7% (v/v) methoxyflurane microdroplets had no apparent anesthetic or toxic effect. The present study demonstrates that methoxyflurane microdroplets produce an anesthetic effect that is highly localized, stable in intensity, ultra-long in duration, and reversible.

Anesthesia for laryngeal laser surgery in the infant and child.

Currently available anesthetic techniques for laryngoscopy and bronchoscopy are briefly evaluated. Recently reported complications from the literature are reviewed. Satisfactory anesthetic techniques are shown to be limited by the physical dimensions of the instruments as well as the extreme limitations of the flow capacity of the small airway itself. The technique used at the Hospital for Sick Children for the past ten years is described. It is based upon spontaneous respiration with inhalation anesthesia, supplemented by topical lidocaine (Xylocaine). Size and age of the patient are not limiting factors. The safety and effectiveness of this technique are supported by representative blood gas studies as well as the clinical records of over 400 cases.

Addictive Effects of Pancuronium and General Anesthetics on an Isolated Rat Intestine Preparation / 대한마취과학회지

The addictive effects by pancuronium on relaxation response to ether, methoxyflurane. halothane, trilene and enfluranc were investigated in the isolated rat intestine preparation. The following results were obtained. 1) Ether in doses of 0.03cc/30ml, 0.1cc/30ml and 0.3cc/30ml produced dose dependent relaxation. 2) Methoxyflurane, halothane, trilene and enflurane in doses of 0.03 cc/30ml, 0.1/30ml and 0.3 cc/30ml did not produce dose dependent relaxation. 3) In the presence of pancuronium in doses of 1 mug/ml and 3mug/ml, ether produced marked dose dependent relaxation respectively in comparison with ether administration alone. 4) In the presence of pancuronium in doses of 1 mug/ml and 3 mug/ml, methoxyflurane, halothane, trilene and enflurane did not produce dose dependent relaxation respectively.