Comparison of Two Different Alfaxalone Concentrations Combined with Midazolam to Anesthetize Cynomolgus Macaques (Macaca fascicularis) for Plethysmography.

Plethysmography is employed in nonhuman primates (NHPs) to calculate respiratory minute volume and determine the exposure time required to deliver an aerosol at the target dose. Anesthetic drugs can impact breathing parameters like steady-state minute volume (SSMV) central to aerosol dosing. Alfaxalone-midazolam mixtures (AM) provide superior parameters for plethysmography in cynomolgus macaques. An obstacle to the use of AM is the volume required to anesthetize via intramuscular injection. A more concentrated formulation of alfaxalone will reduce injection volumes and refine AM protocols. The purpose of this study was to compare AM using the Indexed 10-mg/mL (AM10) formulation compared with an investigational 40-mg/mL (AM40) formulation for IM administration in cynomolgus macaques undergoing plethysmography. We hypothesized that AM10 and AM40 would show no difference in quality of anesthesia (QA), duration of anesthesia, SSMV, accumulated minute volume (AMV), and side effects. We also hypothesized that female macaques would have a longer duration of anesthesia compared with males using both formulations. The study used 15 cynomolgus macaques comprised of 8 females and 7 males. NHPs were compared between 2 separate and randomized anesthetic events no less than one week apart. Each animal served as its own control and animals were randomized by random number generation. Anesthetized NHPs were placed in a sealed plethysmography chamber, and minute volume measurements were calculated every 10 s to determine SSMV. Once SSMV was achieved for 20 min, the trial ended. There were no statistically significant differences between AM10 and AM40 for duration of anesthesia, SSMV, AMV, side effects, or QA. AM40 had a significantly smaller injection volume. Females did not show a significantly longer median duration of anesthesia using either of the alfaxalone formulations. Overall, AM40 offers a more humane anesthetic than AM10 for plethysmography in cynomolgus macaques.

Effects of Midazolam/Dexmedetomidine with Buprenorphine or Extended-release Buprenorphine Anesthesia in C57BL/6 Mice.

The effects of commonly used injectable combinations of anesthetics such as ketamine and xylazine, with or without acepromazine, vary widely across individuals, have a shallow-dose response curve, and do not provide long-term analgesia. These drawbacks indicate the importance of continuing efforts to develop safe and effective injectable anesthetic combinations for mice. In this study, a series of experiments was designed to validate the use of dexmedetomidine and midazolam to provide chemical restraint for nonpainful procedures and the addition of buprenorphine or extended-release buprenorphine to reliably provide a surgical plane of anesthesia in C57BL/6J mice. Loss of consciousness was defined as the loss of the righting reflex (LORR); a surgical plane of anesthesia was defined as the LORR and loss of pedal withdrawal after application of a 300 g noxious stimulus to a hind paw. The combination of intraperitoneal 0.25 mg/kg dexmedetomidine and 6 mg/kg midazolam produced LORR, sufficient for nonpainful or noninvasive procedures, without achieving a surgical plane in 19 of 20 mice tested. With the addition of subcutaneous 0.1 mg/kg buprenorphine or 1 mg/kg buprenorphine-ER, 29 of 30 mice achieved a surgical plane of anesthesia. The safety and efficacy of the regimen was then tested by successfully performing a laparotomy in 6 mice. No deaths occurred in any trial, and, when administered 1 mg/kg atipamezole IP, all mice recovered their righting reflex within 11 min. The anesthetic regimen developed in this study is safe, is reversible, and includes analgesics that previous studies have shown provide analgesia beyond the immediate postsurgical period. Buprenorphine-ER can be safely substituted for buprenorphine for longer-lasting analgesia.

A Comparison of Three Anesthetic Drug Combinations for Use in Inducing Surgical Anesthesia in Female Guinea Pigs (Cavia porcellus).

Guinea pigs are often used in translational research, but providing them with safe and effective anesthesia is a challenge. Common methods like inhalant anesthesia and injectable ketamine/xylazine induce surgical anesthesia but can negatively affect cardiovascular, respiratory, and thermoregulatory systems and complicate the interpretation of research outcomes. Several alternative anesthetic regimens have been investigated, but none have consistently achieved a surgical plane of anesthesia. Therefore, identifying an anesthetic regimen that achieves a stable state of the surgical plane of anesthesia while preserving cardiorespiratory function would be a valuable contribution. To address this issue, we compared the efficacy of 3 anesthetic combinations in female Dunkin-Hartley guinea pigs: 1) alfaxalone, dexmedetomidine, and fentanyl (ADF); 2) alfaxalone, midazolam, and fentanyl (AMF); and 3) alfaxalone, midazolam, fentanyl, and isoflurane (AMFIso). We monitored anesthetic depth, heart rate, oxygenation, respiratory rate, respiratory effort, blood pressure, and body temperature every 15 min from injection to recovery. We also recorded the time to loss of righting reflex, duration of anesthesia, and time to achieve a surgical plane. The results showed no statistically significant differences in induction and recovery times among the groups. In the AMFIso group, 100% of the animals achieved a surgical plane of anesthesia, whereas only 10% of the animals in the AMF group reached that level. None of the animals in ADF group reached a surgical plane of anesthesia. Respiratory rate was significantly lower in the AMFIso as compared with the ADF group (P < 0.001) but was not different between the AMF and ADF groups. Temperature was significantly lower in the AMFIso group as compared with both the ADF and AMF groups (P < 0.001). In conclusion, both combinations of solely injectable anesthetics assessed in this study can be used for short, nonpainful procedures without significant cardiorespiratory depression. However, for mildly to moderately painful surgical procedures, the addition of an inhalant anesthetic like isoflurane is necessary for female guinea pigs.

Validation of the anesthetic effect of a mixture of remimazolam, medetomidine, and butorphanol in three mouse strains.

Proper administration of anesthesia is indispensable for the ethical treatment of lab animals in biomedical research. Therefore, selecting an effective anesthesia protocol is pivotal for the design and success of experiments. Hence, continuous development and refinement of anesthetic agents are imperative to improve research outcomes and elevate animal welfare. "Balanced anesthesia" involves using multiple drugs to optimize efficacy while minimizing side effects. The medetomidine, midazolam, and butorphanol, called MMB, and medetomidine, alfaxalone, and butorphanol, called MAB, are popular in Japan. However, the drawbacks of midazolam, including its extended recovery time, and the narrow safety margin of MAB, have prompted research for suitable alternatives. This study replaced midazolam in the MMB combination with remimazolam (RMZ), which is noted for its ultra-short half-life. The resulting combination, called MRB, was effective in providing a wider safety margin compared to MAB while maintaining an anesthesia depth equivalent level to that of MMB in mice. Notably, MRB consistently exhibited better recovery scores after antagonist administration in contrast to MMB. Furthermore, the re-sedation phenomenon observed with MMB was not observed with MRB. The rapid metabolism of RMZ enables reliable anesthesia induction, circumventing the complications linked to MAB. Overall, MRB excelled in providing extended surgical anesthesia and swift post-antagonist recovery. These results highlight the potential of RMZ for broader animal research applications.

Neurodevelopmental Outcomes after Premedication with Atropine/Propofol vs Atropine/Atracurium/Sufentanil for Neonatal Intubation: 2-Year Follow-Up of a Randomized Clinical Trial.

This study followed 173 newborn infants in the PREmedication Trial for Tracheal Intubation of the NEOnate multicenter, double-blind, randomized controlled trial of atropine-propofol vs atropine-atracurium-sufentanil for premedication before nonemergency intubation. At 2 years of corrected age, there was no significant difference between the groups in death or risk of neurodevelopmental delay assessed with the Ages and Stages Questionnaire. Trial registration Clinicaltrials.gov: NCT01490580.

[Propofol-ketamine versus dexmedetomidine-ketamine for sedation during upper gastrointestinal endoscopy in pediatric patients: a randomized clinical trial]. / Propofol­cetamina versus dexmedetomidina­cetamina para sedação durante endoscopia digestiva alta em pacientes pediátricos: estudo clínico randomizado.

BACKGROUND AND OBJECTIVES: Day-case pediatric sedation is challenging. Dexmedetomidine is a sedative analgesic that does not induce respiratory depression. We compared dexmedetomidine to propofol when it was added to ketamine for sedation during pediatric endoscopy, regarding recovery time and hemodynamic changes. METHODS: We enrolled 120 patients (2-7 years in age) and randomly assigned them into two groups. Each patient received intravenous (IV) ketamine at a dose of 1 mg.kg-1 in addition to either propofol (1 mg.kg-1) or dexmedetomidine (0.5 µg.kg-1). The recovery time was compared. Hemodynamics, oxygen saturation, need for additional doses, postoperative complications and endoscopist satisfaction were monitored. RESULTS: There was no significant difference in hemodynamics between the groups. The Propofol-Ketamine (P-K) group showed significantly shorter recovery times than the Dexmedetomidine-Ketamine (D-K) group (21.25 and 29.75 minutes respectively, p <0.001). The P-K group showed more oxygen desaturation. Eleven and six patients experienced SpO2 <92% in groups P-K and D-K, respectively. A significant difference was noted regarding the need for additional doses; 10% of patients in the D-K group needed one extra dose, and 5% needed two extra doses, compared to 25% and 20% in the P-K group, respectively (p=0.001). The P-K group showed less post-procedure nausea and vomiting. No statistically significant difference between both groups regarding endoscopist satisfaction. CONCLUSIONS: The P-K combination was associated with a shorter recovery time in pediatric upper gastrointestinal endoscopy, while the D-K combination showed less need for additional doses. REGISTRATION NUMBER: Clinical trials.gov (NCT02863861).

Propofol-ketamine versus dexmedetomidine-ketamine for sedation during upper gastrointestinal endoscopy in pediatric patients: a randomized clinical trial / Propofol­cetamina versus dexmedetomidina­cetamina para sedação durante endoscopia digestiva alta em pacientes pediátricos: estudo clínico randomizado

Abstract Background and objectives Day-case pediatric sedation is challenging. Dexmedetomidine is a sedative analgesic that does not induce respiratory depression. We compared dexmedetomidine to propofol when it was added to ketamine for sedation during pediatric endoscopy, regarding recovery time and hemodynamic changes. Methods We enrolled 120 patients (2−7 years in age) and randomly assigned them into two groups. Each patient received intravenous (IV) ketamine at a dose of 1 mg.kg-1 in addition to either propofol (1 mg.kg-1) or dexmedetomidine (0.5 µg.kg-1). The recovery time was compared. Hemodynamics, oxygen saturation, need for additional doses, postoperative complications and endoscopist satisfaction were monitored. Results There was no significant difference in hemodynamics between the groups. The Propofol-Ketamine (P-K) group showed significantly shorter recovery times than the Dexmedetomidine-Ketamine (D-K) group (21.25 and 29.75 minutes, respectively, p < 0.001). The P-K group showed more oxygen desaturation. Eleven and 6 patients experienced SpO2 < 92% in groups P-K and D-K, respectively. A significant difference was noted regarding the need for additional doses; 10% of patients in the D-K group needed one extra dose, and 5% needed two extra doses, compared to 25% and 20% in the P-K group, respectively (p = 0.001). The P-K group showed less post-procedure nausea and vomiting. No statistically significant difference between both groups regarding endoscopist satisfaction. Conclusions The P-K combination was associated with a shorter recovery time in pediatric upper gastrointestinal endoscopy, while the D-K combination showed less need for additional doses. Registration number Clinical trials.gov (NCT02863861).

Resumo Justificativa e objetivos A sedação ambulatorial pediátrica é um desafio. A dexmedetomidina é um analgésico sedativo que não induz à depressão respiratória. Comparamos a dexmedetomidina ao propofol quando associados à cetamina para sedação durante endoscopia pediátrica, quanto ao tempo de recuperação e às alterações hemodinâmicas. Métodos Foram recrutados 120 pacientes (2−7 anos de idade) que foram aleatoriamente alocados em dois grupos. Cada paciente recebeu cetamina IV na dose de 1 mg.kg‐1, além de propofol (1 mg.kg‐1) ou dexmedetomidina (0,5 µg.kg‐1). Comparamos o tempo de recuperação. A hemodinâmica, saturação de oxigênio, necessidade de doses adicionais, complicações pós‐operatórias e satisfação do endoscopista foram monitoradas. Resultados Não houve diferença significante entre os grupos no que diz respeito à hemodinâmica. O grupo Propofol‐Cetamina (P‐C) apresentou tempos de recuperação significantemente mais curtos do que o grupo Dexmedetomidina‐Cetamina (D‐C) (21,25 e 29,75 minutos respectivamente, p < 0,001). Observou‐se frequência maior de dessaturação de oxigênio no grupo P‐C. Onze e 6 pacientes apresentaram SpO2 < 92% nos grupos P‐C e D‐C, respectivamente. Uma diferença significante foi observada em relação à necessidade de doses adicionais; 10% dos pacientes no grupo D‐C precisaram de uma dose extra e 5% precisaram de duas doses extras, em comparação com 25% e 20% no grupo P‐C, respectivamente (p = 0,001). O grupo P‐C apresentou menos náuseas e vômitos após o procedimento. Não houve diferença estatisticamente significante entre os dois grupos em relação à satisfação do endoscopista. Conclusões A combinação P‐C foi associada a tempo mais curto de recuperação na endoscopia digestiva alta pediátrica, enquanto a combinação D‐C mostrou menor necessidade de doses adicionais. Número de registro Clinical trials.gov (NCT02863861).

Eutectic mixture of local anaesthetics for pain reduction during extracorporeal shockwave lithotripsy: A systematic review and meta-analysis.

A systematic review and meta-analysis was conducted to explore the effect of a eutectic mixture of local anaesthetics (EMLA) on pain reduction during extracorporeal shockwave lithotripsy (ESWL). PubMed, Web of Science, Embase, EBSCO, and Cochrane library databases (updated March 2020) were searched for randomised controlled trials (RCTs) assessing the effect of EMLA for patients that underwent ESWL. The search strategy and study selection process were managed according to the PRISMA statement. Six RCTs were included in the meta-analysis. Overall, the results indicated that EMLA significantly reduced pain compared to the control group (RR = -2.98, 95% CI = -5.82 to -0.13, P = 0.04) with a heterogeneity of I2 = 57% (P = 0.04). Subgroup analysis showed that EMLA did not significantly reduce pain when the patients took an analgesic premedication (RR = -1.46, 95% CI = -5.89 to 2.98, P = 0.52) with a heterogeneity of I2 = 38% (P = 0.52). Conversely, studies without premedication showed a significant pain relief effect (RR = -4.08, 95% CI = -7.36 to -0.65, P = -0.80) with a heterogeneity of I2 = 48% (P = 0.14). Most studies showed there was no difference in the patient's need for analgesics. EMLA was effective for reducing pain during EWSL. However, this analgesic effect was limited and did not reduce the need for analgesics.

Total injectable anesthesia of dogs and cats for remote location veterinary sterilization clinic.

BACKGROUND: Sterilization clinics often occur in remote places where anesthesia machines and compressed oxygen are unavailable. This study describes the use of total injectable anesthesia in dogs and cats presented for sterilization in a remote location. RESULTS: A total of 100 animals were sterilized; 26 female cats (CF), 22 male cats (CM), 28 female dogs (DF), and 24 male dogs (DM). CF were anesthetized with dexmedetomidine (20 mcg/kg), ketamine (8 mg/kg) and hydromorphone (0.1 mg/kg) IM. CM were anesthetized with dexmedetomidine (15 mcg/kg), ketamine (5 mg/kg) and hydromorphone (0.1 mg/kg) IM. Insufficient anesthesia in cats was treated with alfaxalone (1 mg/kg) IM. All cats were administered meloxicam at 0.3 mg/kg SQ. DF were anesthetized with dexmedetomidine (15 mcg/kg), ketamine (7-10 mg/kg) and hydromorphone (0.1 mg/kg) IM. DM were anesthetized with dexmedetomidine (15 mcg/kg), ketamine (5 mg/kg) and hydromorphone (0.1 mg/kg) IM. All dogs had IV catheter and endotracheal tube placed. If SpO2 < 91%, ventilation was assisted with an Ambu bag. Insufficient anesthesia in dogs was treated with alfaxalone (1 mg/kg) IV. All dogs were administered meloxicam at 0.2 mg/kg SQ. Following surgery, atipamezole (0.05-0.1 mg/kg) IM was administered to any patient that did not have voluntary movement. All patients survived and were discharged. Less than 25% of cats and male dogs required supplemental anesthesia. Fifty seven percent of female dogs required supplemental anesthesia. More than 89% of patients (in any group) required atipamezole administration. One cat recovered with agitation and hyperthermia (41.1C/ 106F). Some dogs required ventilatory assistance to remain normoxemic while anesthetized. CONCLUSION: Total injectable anesthesia can be accomplished for remote location sterilization clinics with minimal morbidity.

Influence of Topical Anesthesia on Superficial Sensitivity: A Double-Blind, Randomized, Placebo-Controlled Study on 48 Healthy Subjects.

BACKGROUND: Topical anesthetics are used in noninvasive transdermal anesthesia to decrease the superficial pain sensation threshold during dermatologic surgery. Combined pain relief and sensitivity loss can avoid discomfort during the surgery. OBJECTIVE: The aim of this placebo-controlled study was to compare the efficacy of 3 commonly used topical agents by collating loss of sensitivity over time. MATERIALS AND METHODS: Three topical anesthetic creams, a topical anti-inflammatory cream, and a moisturizing cream were applied on the left volar forearm of each of the 48 healthy Caucasian participants. Sensitivity was assessed with the dynamic 2-point discrimination and the Semmes-Weinstein test at 0, 60, 90, 120, 150, and 180 minutes after cream application. RESULTS: After 180 minutes, benzocaine showed a significantly lower 2-point discrimination reduction than lidocaine alone and a lidocaine and prilocaine mixture. Sensory threshold measurements by the Semmes-Weinstein test after 60 minutes revealed a significantly higher effect with lidocaine alone and with the lidocaine and prilocaine mixture than with benzocaine. CONCLUSION: The authors found a stronger skin sensitivity reduction by the eutectic lidocaine and prilocaine mixture and lidocaine alone compared with benzocaine. We suggest increased discomfort reduction in topical anesthetic supported dermatologic surgery by the eutectic mixture and lidocaine alone.

Evaluation of anaesthetic and cardiorespiratory effects after intramuscular administration of alfaxalone alone, alfaxalone-ketamine and alfaxalone-butorphanol-medetomidine in common marmosets (Callithrix jacchus).

BACKGROUND: Anaesthesia is often required in common marmosets undergoing various procedures. The aim of this study was to evaluate anaesthetic and cardiopulmonary effects of alfaxalone, alfaxalone-ketamine and alfaxalone-butorphanol-medetomidine in common marmosets. METHODS: The following treatments were repeatedly administered to seven female common marmosets: Treatment A, alfaxalone (12 mg kg-1 ) alone; treatment AK, alfaxalone (1 mg animal-1 ) plus ketamine (2.5 mg animal-1 ); treatment AMB, alfaxalone (4 mg kg-1 ), medetomidine (50 µg kg-1 ) plus butorphanol (0.3 mg kg-1 ); and treatment AMB-Ati, AMB with atipamezole at 45 minutes. RESULTS AND CONCLUSIONS: Marmosets became laterally recumbent and unresponsive for approximately 30 minutes in A and AK and for approximately 60 minutes in AMB. The animals showed rapid recovery following atipamezole injection in AMB-Ati. The decrease in heart rate and SpO2 was significantly greater in AMB compared to A and AK. Oxygen supplementation, anaesthetic monitors and atipamezole should be available especially when AMB is administered.

Sedative effects of two doses of alfaxalone in combination with methadone and a low dose of dexmedetomidine in healthy Beagles.

OBJECTIVE: To evaluate the sedative effects of two doses of alfaxalone when added to a combination of dexmedetomidine and methadone injected intramuscularly (IM) in healthy Beagles. STUDY DESIGN: Randomized, blinded, crossover, experimental study. ANIMALS: A group of six adult Beagles. METHODS: Dogs were sedated on three different occasions with IM dexmedetomidine (3 µg kg-1) and methadone (0.3 mg kg-1) combined with two doses of alfaxalone (0.5 and 1 mg kg-1; A0.5 and A1, respectively) or saline (A0). Quality of sedation, response to tail clamping and rectal temperature were recorded at baseline, 5, 15, 25, 35 and 45 minutes. Pulse and respiratory rates, oxygen saturation of haemoglobin (SpO2) and noninvasive blood pressure (NIBP) were recorded every 5 minutes. Onset of sedation and duration of recumbency, response to venous catheterization and recovery quality were assessed. Physiological variables (analysis of variance) were analysed between treatments and within treatments compared with baseline (Student t test). Nonparametric data were analysed using Friedman and Cochran's Q tests. Significance was p < 0.05. RESULTS: Sedation scores were significantly higher when alfaxalone was co-administered (area under the curve; p = 0.024, A0.5; p = 0.019, A1), with no differences between doses. Onset of sedation was similar, but duration of recumbency was longer in A0.5 than in A0 [median (minimum-maximum), 43 (35-54) versus 30 (20-47) minutes, p = 0.018], but not in A1. Response to venous catheterization and tail clamping, and quality of recovery (acceptable) presented no differences between treatments. A decrease in all physiological variables (compared with baseline) was observed, except for NIBP, with no differences between treatments. All dogs required oxygen supplementation due to reduced SpO2. CONCLUSIONS AND CLINICAL RELEVANCE: Adding alfaxalone to methadone and dexmedetomidine enhanced sedation and duration of recumbency. Although cardiopulmonary depression was limited, oxygen supplementation is advisable.

Combined spinal epidural for labour analgesia and caesarean section: indications and recommendations.

PURPOSE OF REVIEW: Even if its use is scarce in most countries, many articles concerning combined spinal epidural (CSE) were published. In this review, we present the latest advances concerning CSE in obstetrics. RECENT FINDINGS: During labour, CSE improves epidural analgesia quality. Epidural with intradural opioids can produce maternal hypotension and foetal heart rate abnormalities (FHR-Ab), without increasing the caesarean section rate. For caesarean section, CSE decreases the neuraxial block failure rate, with no significant increase of complications. Epidural volume extension (EVE) after CSE for caesarean section could be an interesting option even though more evidence is needed. SUMMARY: For labour analgesia, CSE has the fastest onset time of analgesia. Its side effects have no consequences on maternal, labour or foetal outcomes. It provides better analgesia than epidural analgesia and can be used for external cephalic version and high-risk patients. For caesarean section, CSE has become the reference neuraxial technique for low-dose spinal anaesthesia, with higher success rate compared with regular spinal anaesthesia. Recent systematic revisions did not confirm this superiority. CSE offers the advantage of EVE, intraoperative top-ups, postoperative administration of neuraxial opioids and local anaesthetics. The risk of complications is balanced by the benefits of the technique.

Different Reactions of Zebra Finches and Bengalese Finches to a Three-Component Mixture of Anesthetics.

Kawai et al. (2011) recently introduced a mixture of three anesthetic agents (here called MMB) that has an effect similar to ketamine/xylazine in mice, which might allow more effective reaction to changes in the animal condition, as an antagonist is available, and which can be used without license for handling narcotic drugs. Using Kawai's study as a baseline, we tested whether this anesthesia and its antagonist can also be used in avian studies. In the present study, we used two species, the zebra finch and the Bengalese finch, of the avian family Estrildidae. In zebra finches, anesthesia effects similar to the use of ketamine/xylazine and to those obtained in mice can be reached by the use of MMB if a higher dose is applied. MMB leads to more variable anesthesia, but has the advantage of a longer time window of deep anesthesia. An antagonist to one component of MMB reduced the awaking time, but was not as effective as in mice. For Bengalese finches, MMB cannot be generally recommended because of difficult handling and high mortality rate when used without antagonist, but could be used for perfusions instead of pentobarbital.

Lidocaine Reduces Sevoflurane Consumption and Improves Recovery Profile in Children Undergoing Major Spine Surgery.

BACKGROUND Intravenous lidocaine administered during surgery improves postoperative outcomes; however, few studies have evaluated the relationship between intravenous lidocaine and volatile anesthetics requirements. This study assessed the effects of lidocaine treatment on sevoflurane consumption and postoperative consciousness disorders in children undergoing major spine surgery. MATERIAL AND METHODS Patients were randomly divided into 2 treatment groups: lidocaine and placebo (control). The lidocaine group received lidocaine as a bolus of 1.5 mg/kg over 30 min, followed by a continuous infusion at 1 mg/kg/h to 6 h after surgery. The following data were assessed: end-tidal sevoflurane concentration required to maintain a bispectral index BIS between 40 and 60, intraoperative blood pressure, heart rate, demand for fentanyl, and consciousness level assessed after surgery using the Richmond Agitation-Sedation Scale. Any treatment-related adverse events were recorded. RESULTS Compared to the control group, lidocaine treatment reduced by 15% the end-tidal sevoflurane concentration required to maintain the intraoperative hemodynamic stability and appropriate level of anesthesia (P=0.0003). There were no intergroup differences in total dose of fentanyl used, average mean arterial pressure, or heart rate measured intraoperatively. The postoperative level of patient consciousness did not differ during the first 6 h between groups. After 9 h, more patients in the control group were still sleepy (P=0.032), and there were fewer perioperative complications in the lidocaine group. CONCLUSIONS Lidocaine treatment decreases sevoflurane consumption and improves recovery profiles in children undergoing major spine surgery.

Current Trends in Anesthesia Management in Hallux Valgus.

Anesthesia management during hallux valgus surgery trends toward multimodal pain control. Locoregional anesthesia with peripheral nerve blocks and wound instillation increase pain control. Peripheral nerve blocks as first-line analgesia are effective with minimal side effects. Local wound instillation has a variable but positive effect with minimal negative side effects. Nonsteroidal anti-inflammatory drugs in bone-to-bone healing remain controversial; however, they reduce opiate requirements and enhance patient satisfaction. Opiate agonists remain the mainstay for postoperative pain; long-acting formulations minimize pain crises. Multimodal analgesia with locoregional anesthesia facilitate the progress of hallux valgus surgery as an outpatient procedure.

Cross-sectional survey of anaesthesia and analgesia protocols used to perform routine canine and feline ovariohysterectomies.

OBJECTIVE: To collect baseline descriptive data on the anaesthesia and analgesia protocols used by New Zealand veterinarians in first-opinion practice when performing routine canine and feline ovariohysterectomies. STUDY DESIGN: Cross-sectional survey. ANIMALS: Not applicable. METHODS: An online survey was conducted asking respondents for: 1) preoperative patient assessment; 2) preanaesthetic medication and induction drugs used; 3) anaesthesia maintenance drug choices and monitoring equipment used; and 4) postoperative analgesia drug selections and monitoring for ovariohysterectomy performed in healthy adult dogs and cats. RESULTS: The survey was completed by 472 veterinarians, of whom 282 provided responses for canine ovariohysterectomy and 361 provided responses for feline ovariohysterectomy. Approximately 23% of canine ovariohysterectomies and 13% of feline ovariohysterectomies had preanaesthetic bloodwork performed. There were 74 unique premedication/induction drug combinations reported for canine ovariohysterectomies and 94 for feline ovariohysterectomies. The most commonly used drug combinations were acepromazine, morphine ± propofol and butorphanol, ketamine and medetomidine for canine and feline ovariohysterectomies respectively. Most animals were intubated, and anaesthesia was maintained with isoflurane in oxygen. Use of intravenous catheters, fluid administration, heat support, and monitoring equipment varied. There were 41 unique postoperative analgesia drug combinations reported for canine ovariohysterectomies and 20 for feline ovariohysterectomies. Canine ovariohysterectomies were most commonly administered injectable opioids on the day of surgery followed by 3 days of oral non-steroidal anti-inflammatory drugs (NSAIDs), whereas feline ovariohysterectomies were usually administered a single injection of an opioid or NSAID or both on the day of surgery. Most animals were seen within 7-10 days for re-examination and/or suture removal. CONCLUSIONS AND CLINICAL RELEVANCE: Veterinarians use a wide range of anaesthesia and analgesia protocols for routine ovariohysterectomies. Further research is needed comparing the safety and efficacy of commonly used protocols to determine whether there are opportunities to improve the level of patient welfare.

Refraction under general anesthesia in children, using cycloplegic refraction only as a reference.

PURPOSE: To compare the measurements of cycloplegic refraction and refraction (R1-1) under general anesthesia (GA) when using the same portable auto-refractometer (ARF) in pediatric patients. METHODS: 36Thirty-six to 60-month-old patients who underwent refraction measurements using a portable ARF (Retinomax® K plus 3, Righton, Japan), who did not receive prior cycloplegics under this GA and who had cycloplegic refraction using 1% cyclopentolate and the same Retinomax® device < 3 months prior this GA, between 2015 and 2018, were included in this study. The agreement (Bland-Altman analysis) and correlation (Pearson correlation) between the mean values of the measurements were analyzed. RESULTS: Two-hundred-twenty-two right eyes of 222 patients (114 male and 108 female) were included in this study. The mean age was 45.04 ± 11.24 months. The mean spherical refractions (R1-1, R2-1) under GA and cycloplegic refraction were 1.08 ± 3.50 diopter (D) (-8.00 to +8.00) and 2.58 ± 3.28 D (-6.50 to +9.25), respectively. A strong positive correlation was detected between the two measurements (r = 0.95). When comparing measurements, the mean measurement under GA was -1.49 D (95% confidence interval: lower limit, -3.63; upper limit, +0.63) more myopic than the mean cycloplegic refraction (R1-1) value (Bland-Altman analysis test). The differences between the measurements were within ± 1 D in 92 eyes (41.44%) and within ± 2 D in 180 eyes (81.01%). No significant difference was detected when comparing the cylindrical refractive error values (p > .05). CONCLUSION: Refractive measurements under GA were more myopic than cycloplegic refraction (R1-1) measurements. It is important to consider that complete cycloplegia is not achieved under GA.

EVALUATION OF TWO DOSES OF BUTORPHANOL-MEDETOMIDINE-MIDAZOLAM FOR THE IMMOBILIZATION OF WILD VERSUS CAPTIVE BLACK-FOOTED CATS (FELIS NIGRIPES).

The efficacy, safety, physiologic effects, and reversibility of butorphanol-medetomidine-midazolam (BMM) immobilization were evaluated in black-footed cats (Felis nigripes) and compared between captive and wild animals. Nine captive and 14 wild black-footed cats were hand injected into an accessible hind limb muscle group with the BMM combination. The captive cats (captive group) received a lower dose of the combination (butorphanol, 0.25 ± 0.03 mg/kg; medetomidine, 0.06 ± 0.01 mg/kg; midazolam, 0.13 ± 0.02 mg/kg), whereas the wild cats received a higher dose (butorphanol, 0.53 ± 0.11 mg/kg, medetomidine, 0.13 ± 0.03 mg/kg, midazolam, 0.27 ± 0.05 mg/kg). Two capture methods were required to restrain the wild cats; previously collared cats were tracked and excavated out of their burrows during daylight hours (excavated group), whereas uncollared cats were randomly located using spotlights and pursued by a vehicle at night (pursued group). Inductions were rapid and no spontaneous arousals occurred. Mean arterial blood pressure in all cats was within normal limits for domestic cats. Initial rectal temperatures varied greatly among the groups, but decreased in all groups as the immobilization progressed. In the pursued animals, heart rates and respiratory rates were initially elevated. All cats had moderate hypoxemia, hypocapnia, and metabolic acidosis. Intramuscular administration of naltrexone, atipamezole, and flumazenil resulted in rapid, uncomplicated recoveries. BMM is thus a safe, effective immobilizing drug combination for both captive and wild black-footed cats, but higher doses are required in wild animals. The capture methods exerted a greater influence on the physiology of the immobilized animals than did the doses of the drugs used. Although this drug combination can be used safely to immobilize black-footed cats, supplemental oxygen should always be available for use, especially in pursued animals due to hypoxia.

ANESTHESIA WITH MEDETOMIDINE-KETAMINE AND DEXMEDETOMIDINE-KETAMINE IN MOUNTAIN GORILLAS (GORILLA BERINGEI BERINGEI).

Between December 2002 and September 2017, 125 anesthetic procedures involving free-living and orphaned captive mountain gorillas (Gorilla beringei beringei) were performed in the Virunga Massif and Bwindi Impenetrable Forest in East-Central Africa. Of these 125 immobilizations, 114 records were complete enough for inclusion into this study. Anesthetic and physiologic data from these 114 cases were analyzed, of which 57 used medetomidine-ketamine and 57 used dexmedetomidine-ketamine administered intramuscularly. With the use of estimated weights, the mean induction dosage (mg/kg ± SD) for medetomidine was 0.033 ± 0.003 (n = 42), for dexmedetomidine 0.018 ± 0.005 (n = 53), and for ketamine 3.66 ± 0.95 (n = 95). Mean time from injection of induction dose to recumbency was 6.8 ± 3.1 min (n = 74). Atipamezole was administered intramuscularly to reverse anesthesia. First signs of recovery occurred at 5.0 ± 4.0 min, and full recovery was 19.0 ± 17.0 min after administration of the reversal agent. No significant differences in physiologic parameters or anesthetic time variables were noted between healthy and unhealthy individuals. Mean heart rate was 72.0 ± 17.6 beats/min (n = 83) and mean oxygen saturation was 96.5% ± 4.2 (n = 62). Mean respiratory rate was 27 ± 9 breaths/min (n = 84) and mean body temperature 36.6°C ± 1.2 (n = 61). The current protocol has several advantages for field use in this species given its quick induction, few observed side effects, and ability to reverse so that the animal can return more quickly to its social group.