Electroencephalographic and physiologic changes after tricaine methanesulfonate immersion of African clawed frogs (Xenopus laevis)

The objective of this study was to determine electroencephalographic and complementary physiologic changes in Xenopus leavis frogs after bath immersion in MS222. We also evaluated the addition of sodium pentobarbital injected intracoelomi- cally 2 h after MS222 immersion to achieve euthanasia. Frogs (n = 9) weighing 105.5 ± 8.4 g (mean ± 1 SD) were immersed in MS222 at either 1 or 3 g/L until anesthesia was achieved; a conductive stainless steel screw then was implanted in the skull on top of the outer pial surface of the brain. Frogs were immersed again in MS222 at the same concentration as previously, and electroencephalograms, heart rate, oxygen saturation, and respiratory movements were recorded. Amplitude and mean frequency of the electroencephalographic signal were evaluated at 15-min intervals until a flat-line signal was achieved. At 2 h after induction, frogs were injected intracoelomically with sodium pentobarbital (0.5 mL; 240 mg/mL) to accelerate euthanasia. Immersion of frogs in 1 or 3 g/L of MS222 depressed cerebral activity within 30 min without a significant effect on cardiac function. Intracoelomic injection of sodium pentobarbital at 2 h after MS222 administration rapidly (3.2 ± 1.7 min) induced cardiac arrest. In conclusion, immersion in MS222 can be used for the collection of organs from X. laevis frogs, but the addition of pentobarbital is required to achieve euthanasia.

Sedation and anesthesia for CT: emerging issues for providing high-quality care

During the past decades, the use of CT to diagnose conditions and monitor treatment in the pediatric setting has increased. Infants and children often require procedural sedation to maintain a motionless state to ensure high-quality imaging. Various medication regimens have been recommended to achieve satisfactory sedation for this painless procedure. While the incidence of adverse events remains low, procedural sedation carries the risk of serious morbidity and mortality. The use of evidence-based, structured approaches to procedural sedation should be used to reduce variation in clinical practice and improve outcomes.

Evaluation of methods of rapid mass killing of segregated early weaned piglets

The operational logistics of mass killing of healthy, surplus piglets by manual blunt force trauma, controlled blunt force trauma, intraperitoneal injection of barbiturate, and free bullet were recorded. Objective performance variables evaluated were, speed of application, human resource and input cost, animal restraint required, and failure rate. Subjective evaluation of esthetics and difficulty of application indicated manual blunt force trauma is an unacceptable technique. Under field conditions, physical methods of killing were superior to intraperitoneal injection of concentrated pentobarbital. Considering animal welfare metrics in isolation, controlled blunt force trauma was superior to all other techniques attempted.

Sedative, hypnotic and anticonvulsant activities of the ethanol fraction from Rhizoma Pinelliae Praeparatum

ETHNOPHARMACOLOGICAL RELEVANCE

Rhizoma Pinelliae Praeparatum is the product of raw Rhizoma Pinellia processed with alkaline solution and Licorice, which had been widely used for treatment of insomnia in traditional Chinese medicine. The present study aimed to investigate the sedative, hypnotic and anticonvulsant activities of ethanol fraction from Rhizoma Pinelliae Praeparatum (EFRP) and to determine whether these effects were related to GABAergic mechanism.

MATERIALS AND METHODS

The sedative, hypnotic and anticonvulsant activities of EFRP were investigated with locomotion activity, pentobarbital-induced sleeping and nikethamide (NKTM)-induced convulsion tests, respectively. Additionally, the effects of flumazenil (an antagonist of GABA(A) receptor) and L-malic acid (blocker of synthetic enzyme for GABA) on the hypnotic activity of EFRP were evaluated.

RESULTS

EFRP at dose of 12 g/kg significantly inhibited the locomotion activity of mice. EFRP showed synergic effect on pentobarbital-induced sleeping by increased numbers of mice falling asleep, reduced the sleep latency and prolonged the sleeping time. L-malic acid and flumazenil inhibited the augment effects of EFRP on pentobarbital-induced sleeping. EFRP promoted a significant protection to NKTM-induced convulsion, by prolonged the death latency and decreased mortality.

CONCLUSION

EFRP possessed sedative, hypnotic and anticonvulsant activities and these activities may be related to the GABAergic system.

[Behavioral correlations of gradual forced administration of psychoactive drugs]

The study was aimed at evaluating the behavioral correlations of the forced administration of psychoactive drugs. Wistar rats received the following drugs in elevated doses (over 4 days, i. p.): (i) physiological saline (control; 0.1-0.2-0.4-0.8 ml/rat), (ii) psychostimulant amphetamine (0.5-1.0--2.0-4.0 mg/kg); (iii) opioid analgetic fentanyl (0.00625-0.0125--0.025-0.05 mg/kg), (iv) ethanol 40% solution (0.5-1.0--2.0-4.0 g/kg), (v) barbiturate sodium ethaminal (2.5-5--10-20 mg/kg); and(vi) synthetic glucocorticoid dexamethasone (0.5-1.0--2.0-4.0 mg/kg). The forced regime of drug administration led to gradual load of the organism and prevented drug tolerance. The dynamics of self-stimulation reaction of the lateral hypothalamus was registered every day over drug administration period and revealed the following regularities: (I) dose-dependent effect of psychostimulant amphetamine and opioid analgetic fentanyl; (II) dexamethasone modulated self-stimulation, increasing (2 day, 1 mg/kg) or decreasing it (3 day, 2 mg/kg); (III) ethanol (1-2 g/kg) activated self-stimulation slightly; (IV) sodium ethaminal slightly inhibited self-stimulation and increased the thresholds of self-stimulation. In 24 h and 72 h after the last administration of drugs, the rat behavior was assessed in open field, elevated plus maze, resident-intruder paradigm, and Porsolt's test. In the open field, significant signs of post-intoxication exposure of psychoactive drugs were revealed, which were registered for 24-72 h after drug withdrawal. The withdrawal of drugs was accompanied with reduction (in 24 h) and subsequent recovery (in 72 h) of the vertical motor activity, exploration behavior, and emotionality. The anxiety indexes were increased up to the 3rd day after withdrawal. The antidepressant effect was also increased. The system of aggression-defense was restored only in rats treated with ethanol. The indexes of individual behavior and communicability in the post-intoxication period were decreased as well. It is suggested that the forced regime of drug administration in increasing doses with subsequent withdrawal of drug injections is a suitable method to evaluate the behavioral elements of drug dependence.

Survey of euthanasia practices in animal shelters in Canada

Questionnaires on methods of euthanasia used in Canadian animal shelters were sent to 196 Canadian animal shelters yielding 67 responses. Sodium pentobarbital injection was the only method of euthanasia used by 61% of establishments that euthanized dogs and 53% of the establishments that euthanized cats. Many of these establishments used pre-medication. Sodium pentobarbital was mostly administered intravenously but some establishments also used intracardiac and intraperitoneal routes, and some only used intracardiac administration for cats. T-61 injection was the only method of euthanasia used by 23% of the establishments that euthanized dogs and 35% of the establishments that euthanized cats. All of these establishments used pre-medication, but the percentages of establishments that only used the intravenous route for administration of T-61 in dogs and cats were 45% and 7%, respectively. Further studies on the use of T-61, and the training and provision of counselling services for staff are recommended.

Hypnotic effect of jujubosides from Semen Ziziphi Spinosae

ETHNOPHARMACOLOGICAL SIGNIFICANCE

Semen Ziziphi Spinosae, the seed of Ziziphus jujuba Mill. var. spinosa (bunge) Hu ex H.F. Chow has been widely used in treating insomnia and anxiety.

AIM OF THE STUDY

In this study, we investigated the hypnotic effect of jujubosides, one of the major components (saponin) of Semen Ziziphi Spinosae, in both day and night period.

MATERIALS AND METHODS

After the administration of jujubosides (9 mg/kg once per day for 3 days), sleep parameters were examined by EEG and EMG analysis in normal rats and the action of jujubosides on pentobarbital-induced sleep assessed by the loss-of righting reflex.

RESULTS

During daytime (9:00-15:00), jujubosides significantly increased the total sleep and rapid eye movement (REM) sleep without significant influence on non-REM (NREM) sleep. During nighttime (21:00-3:00), jujubosides significantly increased the total sleep and NREM sleep especially the light sleep while showed no significant effect on REM sleep and slow wave sleep (SWS). In pentobarbital-treated mice, jujubosides significantly augmented the hypnotic effect of pentobarbital (45 mg/kg, i.p.), proved by increasing sleep time and this augmentative effect was potentiated by 5-hydroxytryptophan (2mg/kg, i.p.). Furthermore, jujubosides inhibited the para-chlorophenylalanine-induced suppression of pentobarbital-induced hypnosis.

CONCLUSIONS

These results suggested that the hypnotic effect of jujubosides on normal rats may be influenced by circadian rhythm and the serotonergic system may involve in the hypnotic effect of jujubosides. Jujubosides may be good source of lead compounds for novel hypnotics.

[Euthanasia of cattle: a clinical comparison of T 61 and pentobarbital (Eutha 77)]

The objective of this study was a comparison of pentobarbital and T 61 in the euthanasia of cattle. 397 cattle of different ages and breeds which had to be euthanised in the Clinic for Ruminants were enrolled. Following clinical examination, euthanasia was performed by intravenous injection of either 40 mg pentobarbital per kg body weight (BW) (0.1 ml Eutha 77) or 0.1 ml T 61/kg BW. The intervals between the beginning of injection and the following events were noted: collapse of the animal, cessation of respiration, cessation of cardiac action, disappearance of the palpebral and corneal reflexes, and maximum dilatation of the pupils. These post-injection events occurred significantly earlier with Eutha 77. In addition, events like excitations and vocalisations were recorded. Excitations occurred twice as often with T 61 (in 34% of cases) than with Eutha 77 (17%), and strong excitations (grade 3 of 3) were also more frequent with T 61 (9.8%) than with Eutha 77 (3%). Vocalisations were less frequent (30%) with T 61 than with pentobarbital (39%), but this difference was not significant. Severe vocalisations occurred very rarely. With both drugs, intervals between the beginning of injection until cessation of reflexes were longer in older animals. Following injection of Eutha 77, cessation of the corneal reflex and maximal dilatation of the pupils occurred earlier in cattle with severe disturbance of the general condition than in cattle with lesser disturbance; in the T 61-group this difference was only significant for the interval until cessation of the corneal reflex. In anaesthetized patients euthanized with T 61 cessation of cardiac action and respiration occurred earlier than in patients that were not under general anaesthesia when euthanized; in the Eutha 77 group, the difference was significant only for the interval until cessation of cardiac action.

Euthanasia method for mice in rapid time-course pulmonary pharmacokinetic studies

To develop a means of euthanasia to support rapid time-course pharmacokinetic studies in mice, we compared retroorbital and intravenous lateral tail vein injection of ketamine-xylazine with regard to preparation time, utility, tissue distribution, and time to onset of euthanasia. Tissue distribution and time to onset of euthanasia did not differ between administration methods. However, retroorbital injection could be performed more rapidly than intravenous injection and was considered to be a technically simple and superior alternative for mouse euthanasia. Retroorbital ketamine-xylazine, CO(2) gas, and intraperitoneal pentobarbital then were compared as euthanasia agents in a rapid time-point pharmacokinetic study. Retroorbital ketamine-xylazine was the most efficient and consistent of the 3 methods, with an average time to death of approximately 5 s after injection. In addition, euthanasia by retroorbital ketamine-xylazine enabled accurate sample collection at closely spaced time points and satisfied established criteria for acceptable euthanasia technique.

Evaluation and refinement of euthanasia methods for Xenopus laevis

The most common method of euthanasia for Xenopus species is by immersion in tricaine methane sulfonate solution (MS222). A wide range of doses of MS222 (0.5 to 5 g/L) have been recommended, but few reports describe dose-response testing, the time to loss of consciousness, or the reliability of euthanasia. The objective of this study is to evaluate the efficacy of immersing individual and groups of frogs in MS222 at concentrations ranging from 1 to 5 g/L for euthanasia and of 3 less-common methods: intracoelomic injection of MS222, intracoelomic injection of sodium pentobarbital with phenytoin, and ventral cutaneous application of benzocaine gel. Our results indicate that immersion for at least 1 h in a 5-g/L buffered solution of MS222, intracoelomic injection of 1100 mg/kg sodium pentobarbital with sodium phenytoin (equivalent to 0.3 mL solution per frog), or ventral cutaneous application of 182 mg/kg benzocaine (equivalent to a 2 cm x 1 mm of 20% benzocaine gel) is necessary to euthanize adult X. laevis and ensure complete cessation of the heartbeat without recovery. These doses are considerably higher than those previously recommended for this species.

[Expression of mRNA for corticoliberin and vasopressin in hypothalamus and amygdala on the background of administration of psychoactive drugs in rats]

Wistar male rats were injected intraperitoneally for 4 days in elevated doses with: (1) physiological saline (control; 0.1 - 0.2 - 0.4 - 0.8 ml/rat), (2) amphetamine (0.5 - 1.0 - 2.0 - 4.0 mg/kg); (3) fentanyl (0.00625 - 0.0125 - 0.025 - 0.05 mg/kg), (4) 40% aqueous ethanol solution (0.5 - 1.0 - 2.0 - 4.0 g/kg), (5) ethaminal sodium (2.5 - 5 - 10 - 20 mg/kg), and (6) dexamethasone (0.5 - 1.0 - 2.0 - 4.0 mg/kg). The forced regime of drug administration led to gradual load of the organism and prevented drug tolerance development. This method is widely used for the formation of drug dependence (or its features) due to various narcotic agents. The maximum level of mRNA expression for corticoliberin was registered in amygdala after the administration of dexamethasone (0.46 units compared to beta-actin), and the minimum level was observed after treatment with sodium ethaminal (0.07) and fentanyl (0.037). In hypothalamus, sodium ethaminal produced elevated mRNA expression (0.8 units), followed by ethanol (0.37) and fentanyl (0.039). Amphetamine activated mRNA expression for corticoliberin neither in hypothalamus nor in amygdala for all of the drugs studied. The mRNA expression for vasopressin was also not registered for all drugs in hypothalamus and amygdala. Therefore, the reinforcing system of hypothalamus supports the typical reaction on the administration of narcotic agents, while the extended amygdala system includes both the proper reinforcement and the stress reactivity elements.

Functional magnetic resonance imaging of hearing-impaired children under sedation before cochlear implantation

OBJECTIVE

To investigate functional magnetic resonance imaging (fMRI) in pediatric cochlear implantation candidates with residual hearing who are under sedation for evaluation of auditory function.

DESIGN

During fMRI, subjects heard a random sequence of tones (250-4000 Hz) presented 10 dB above hearing thresholds. Tones were interleaved with silence in a block-periodic fMRI design with 30-second on-off intervals. Twenty-four axial sections (5 mm thick) covering most of the brain were obtained every 3 seconds for a total acquisition time of 5.5 minutes.

SETTING

Single tertiary academic medical institution.

PATIENTS

Severely to profoundly hearing-impaired children (n=10; mean age, 49.1 months). During fMRI, subjects were awake (n=2) or sedated with pentobarbital sodium if their weight was 10 kg or greater (n=4) or chloral hydrate if their weight was less than 10 kg (n=4).

MAIN OUTCOME MEASURES

Detection of brain activation by fMRI in the primary auditory cortex (A1) in hearing-impaired patients under sedation, and correlation of A1 activation with hearing levels measured after cochlear implantation.

RESULTS

In most subjects, fMRI detected significant levels of activation in the A1 region before cochlear implantation. The improvement in hearing threshold after cochlear implantation correlated strongly (linear regression coefficient, R=0.88) with the amount of activation in the A1 region detected by fMRI before cochlear implantation.

CONCLUSIONS

Functional MRI can be considered a means of assessing residual function in the A1 region in sedated hearing-impaired toddlers. With improvements in acquisition, processing, and sedation methods, fMRI may be translated into a prognostic indicator for outcome after cochlear implantation in infants.

Dragon's blood from Croton urucurana (Baill.) attenuates visceral nociception in mice

Dragon's blood, the red sap from Croton urucurana Baill. (Euphorbiaceae) has a profound history of traditional use in conditions such as inflammation, diarrhoea and gastrointestinal distress. Previous studies established its anti-inflammatory, antidiarrhoeal and analgesic properties and in this study we verified its potential to suppress visceral pain, using capsaicin- and cyclophosphamide-induced models of visceral nociception. Mice that received intra-colonic capsaicin (0.3%, 50 microl/animal) or intraperitoneal injection of cyclophosphamide (400 mg/kg) manifested spontaneous nociceptive behaviors or crises, which were significantly suppressed in animal groups treated with red sap (200 and 400 mg/kg, p.o.) or that received N-acetylcysteine (750 mg/kg, i.p.) or morphine (7.5 mg/kg, s.c.), as positive controls. In capsaicin model, the antinociception produced by 200 mg/kg red sap was found to be naloxone-sensitive (2 mg/kg, i.p.), suggesting an opioid mechanism. In tests of open-field and pentobarbital-sleeping time, mice received 200mg/kg red sap showed no significant alterations in either locomotion frequency or on sleeping time, indicating that the observed antinociception is not a consequence of sedation or motor abnormality. These findings highlight the visceral antinociceptive property of Croton urucurana sap and further support its ethno-medical use to alleviate pain associated with gastrointestinal and other related disorders.

Pharmacological studies on the sedative and hypnotic effect of salidroside from the Chinese medicinal plant Rhodiola sachalinensis

This is the preliminary study of sedative and hypnotic activity of salidroside (a major component of Rhodiola sachalinensis) in mice by using synergism with pentobarbital as an index for the hypnotic effect. Loss of the righting reflex was used to determine the start of sleep. Sleep latency and sleeping time were evaluated in this experiment. The results showed that salidroside could obviously shorten the sleep latency and prolong the sleeping time of mice produced by pentobarbital sodium (55 mg/kg, i.p.). Salidroside produces significant sedative-hypnotic effect. The dose-effect relationship is remarkable.

Endotoxin-induced acute lung injury and organ dysfunction are attenuated by pentobarbital anaesthesia

1. Acute lung injury (ALI) as a result of sepsis is a major cause of mortality. Certain anaesthetic agents have been reported to suppress pro-inflammatory cytokines and inducible nitric oxide (NO) synthase (iNOS) activities. We investigated the effects of pentobarbital on ALI and organ functions after the administration of endotoxin. 2. Intravenous (i.v.) pentobarbital (20 or 40 mg/kg) was administered 5 min after lipopolysaccharide (LPS; 10 or 30 mg/kg via i.v. infusion). To avoid hypoxia and/or hypercapnia following anaesthesia, we installed a special chamber connected to a rodent ventilator to provide ventilation with 95% oxygen content and 5% nitrogen. The animal was kept at eucapnic conditions (arterial PCO2 at an average of 38 +/- 2 mmHg). 3. We monitored the arterial pressure (AP) and heart rate (HR). Acute lung injury was evaluated by lung weight changes, protein concentration in bronchoalveolar lavage, and Evans blue leakage. Plasma nitrate/nitrite, methyl guanidine and biochemical factors were determined. Pathological and immunofluorescent examinations were performed to observe the lung changes and to determine the activities of pro-inflammatory cytokines, nitrotyrosine and iNOS. 4. Lipopolysaccharide caused dose-dependent systemic hypotension with an increase in the extent of ALI. The lung pathology included oedema and inflammatory cell infiltration. Accompanying the ALI, LPS elevated plasma nitrate/nitrite, methyl guanidine, blood urea nitrogen, lactic dehydrogenase, creatinine phosphokinase, glutamic transaminase and amylase. The lung tissue content of tumour necrosis factor-alpha, interleukin-lbeta, iNOS and nitrotyrosine was increased following LPS administration. These changes were abrogated by pentobarbital anaesthesia. 5. Our results indicated that pentobarbital anaesthesia significantly augmented the LPS-induced systemic hypotension. However, it attenuated the LPS-induced ALI and organ dysfunctions. This agent also improved the survival rate following LPS at high and low doses. This mechanism may be related to the inhibitory effects on the increases in the production or activity of NO, free radicals, pro-inflammatory cytokines, nitrotyrosine and iNOS.

[Pharmacological effects of volatile oil of Valeriana amurensis on CNS]

OBJECTIVE

To study the pharmacological effects of volatile oil of Valeriana amurensis on central nervous system.

METHODS

The pharmacological effects of volatile oil of Valeriana amurensis on the autonomic activities of mice, the sleeping synergistic action of mice with pentoharbital sodium at subthreshold and hypnotic dosages, the sleep phases of rats, the writhing response of mice caused by acetic acid and the convulsion of mice induced by thio-semicarbazide were investigated.

RESULTS

The autonomic activities of mice were significantly inhibited by the volatile oil of Valeriana amurensis. The rate of falling sleep and the extension of sleeping time of mice were significantly increased by the synergic action of pentobarbital sodium with the volatile oil. The sleep phases of SWS2 and REMS of rats were obviously extended by the volatile oil of Valeriana amurensis. In addition, the frequency of writhing response of mice caused by acetic acid was reduced, and the convulsion of mice induced by thio-semicarbazide was antagonized with the administration of the volatile oil.

CONCLUSION

The volatile oil of Valeriana amurensis has significantly sedative analgesic and anti-hyperspasmia effects.

Renal function and histology after acute hemorrhage in rats under dexmedetomidine action

PURPOSE: About 50 % of indications for dialysis in acute renal failure are related to problems originated during the perioperative period. Intraoperative hemodynamic changes lead to renal vasoconstriction and hypoperfusion. Previous studies have not defined the dexmedetomidine renal role in hemorrhage situations. This study evaluated the effect of dexmedetomidine on renal function and histology after acute hemorrhage in rats. METHODS: Covered study with 20 Wistars rats, anesthetized with sodium pentobarbital, 50 mg. kg-1, intraperitoneal, randomized into 2 groups submitted to 30% volemia bleeding: DG - iv dexmedetomidine, 3 µg. kg-1 (10 min) and continuous infusion - 3 µg. kg-1. h-1; CG - pentobarbital. For renal clearance estimative, sodium p-aminohippurate and iothalamate were administered. Studied attributes: heart rate, mean arterial pressure, rectal temperature, hematocrit, iothalamate and p-aminohippurate clearance, filtration fraction, renal blood flow, renal vascular resistance, and histological evaluations of the kidneys. RESULTS: DG showed smaller values of heart rate, mean arterial pressure, and renal vascular resistance, but iothalamate clearance and filtration fraction values were higher. There was similarity in p-aminohippurate clearance and renal blood flow. Both groups had histological changes ischemia-like, but dexmedetomidine determined higher tubular dilatation scores. CONCLUSION: In rats, after acute hemorrhage, dexmedetomidine determined better renal function, but higher tubular dilation scores.

Anesthesia increases in vivo N-([18F]fluoroethyl)piperidinyl benzilate binding to the muscarinic cholinergic receptor

The in vivo binding of N-[18F]fluoroethyl-piperidinyl benzilate ([18F]FEPB) to the muscarinic cholinergic receptor was measured in awake and anesthetized rats. Studies were done using an equilibrium infusion technique to provide estimates of specific binding as distribution volume ratios. Anesthesia with either isoflurane or sodium pentobarbital produced a significant (65-90%) increase of radiotracer binding in receptor-rich brain regions (striatum, cortex, hippocampus) relative to awake controls. Pretreatment of anesthetized animals with the acetylcholinesterase inhibitor phenserine produced no further increases in radioligand binding, in contrast to the large (>70%) increases previously observed in awake animals following drug treatment. These studies demonstrate that anesthesia can produce significant changes in baseline biochemical measures that can obscure even very large effects of pharmacological challenges.

Nociception after intraperitoneal injection of a sodium pentobarbitone formulation with and without lidocaine in rats quantified by expression of neuronal c-fos in the spinal cord--a preliminary study

After a search on Medline, it appears that intraperitoneal injection of sodium pentobarbitone is often used for anaesthesia and euthanasia of rodents. In the present pilot study in rats, spinal nociception after intraperitoneal injection of sodium pentobarbitone, with and without lidocaine, was examined by estimation of the number of c-fos-expressing neurones in the spinal dorsal horn. One group of rats received an intraperitoneal injection of 0.4 mL/kg sodium pentobarbitone (100 mg/mL; n=4). Another group of rats received a similar intraperitoneal injection of sodium pentobarbitone formulated with lidocaine 10 mg/mL (n=4); a control group received a similar intraperitoneal injection of 0.9% saline (n=4). After 3 h, the animals were re-anaesthetized and perfused with 4% formaldehyde, and the spinal cord was collected and processed by immunohistochemistry for stereological quantification of the number of neurones with c-fos-like immunoreactivity (FLI). Intraperitoneal injection of the sodium pentobarbitone formulation caused a significantly increased number of neurones with FLI in the spinal cord (3930+/-247; mean+/-SEM; P<0.001) compared with the saline control group (765+/-131). The lidocaine added to the sodium pentobarbitone formulation significantly reduced the number to 2716+/-393 (P<0.05). In conclusion, intraperitoneal injection of sodium pentobarbitone caused a significant increase in nociception which was lowered by adding lidocaine to the formulation, although it was still significantly higher than the control level. Further studies are needed with the aim of optimizing the lidocaine concentration and also to examine the effect of the combination of lidocaine with a long-acting local anaesthetic agent, e.g. bupivacaine.

Sédation au pentobarbital par voie rectale pour enregistrement des PEA chez l'enfant

OBJECTIVES

The aim of our study was to determine if rectal sedation with pentobarbital sodium provides safe and effective sedation for children undergoing auditory brainstem response (ABR) testing.

MATERIAL AND METHODS

A prospective study was conducted in the ENT pediatric department of Robert Debre's hospital (APHP, Paris). 68 children under 8 years of age were given rectal pentobarbital for ABR testing at a dosage of about 5 mg/kg.

RESULTS

61 children of 68 (89.7%) were adequately sedated with rectal pentobarbital. The mean elapsed time from drug administration to full sedation was 36,1 minutes. No adverse event was reported in 84.1% of children.

CONCLUSION

Pentobarbital provides safe and effective sedation. Rectal administration is easy, painless and with brief duration of action. It's a good alternative to general anesthesia for young children undergoing ABR testing.