439 research outputs found

    Intravenous conscious sedation in patients under 16 years of age. Fact or fiction?

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    Recently published guidelines on the use of conscious sedation in dentistry have published varying recommendations on the lower age limit for the use of intravenous conscious sedation. There are a large number of dentists currently providing dental treatment for paediatric patients under intravenous conscious sedation. The 18 cases reported here (age range 11-15 years), were successfully managed with intravenous conscious sedation. The experience in this paper is not sufficient evidence to recommend the wholesale use of intravenous conscious sedation in patients who are under 16 years. The fact that a range of operators can use these techniques on paediatric patients would suggest that further study should be carried out in this population. The guidance should be modified to say there is insufficient evidence to support the use of intravenous conscious sedation in children, rather than arbitrarily selecting a cut off point at age 16 years

    The effect of transmucosal 0.2mg/kg Midazolam premedication on dental anxiety, anaesthetic induction and psychological morbidity in children undergoing general anaesthesia for tooth extraction

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    <b>Background:</b> The project aims were to evaluate the benefit of transmucosal Midazolam 0.2mg/kg pre-medication on anxiety, induction behaviour and psychological morbidity in children undergoing general anaesthesia (GA) extractions. <b>Method:</b> 179 children aged 5-10 years (mean 6.53 years) participated in this randomised, double blind, placebo controlled trial. Ninety children had Midazolam placed in the buccal pouch. Dental anxiety was recorded pre operatively and 48 hours later using a child reported MCDAS-FIS scale. Behaviour at anaesthetic induction was recorded and psychological morbidity was scored by the parent using the Rutter Scale pre-operatively and again one-week later. Subsequent dental attendance was recorded at one, three and six months after GA. <b>Results:</b> Whilst levels of mental anxiety did not reduce overall, the most anxious patients demonstrated a reduction in anxiety after receiving midazolam premedicationmay (p=0.01). Neither induction behaviour nor psychological morbidity improved. Irrespective of group, parents reported less hyperactive (p= 0.002) and more prosocial behaviour (p=0.002) after the procedure:;, older children improved most (p=0.048), Post GA Dental attendance was poor and unrelated to after the procedure and unaffected by premedication. <b>Conclusion:</b> 0.2mg/kg buccal Midazolam provided some evidence for reducing anxiety in the most dentally anxious patients. However, induction behaviour, psychological morbidity and subsequent dental attendance were not found to alter between the premedication groups

    The visitor effect in petting zoo-housed animals: Aversive or enriching?

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    Two studies were carried out on the effect of visitors on mixed-breed goats, llama, and Vietnamese pot-bellied pigs housed in a petting zoo display within a safari park. In the first study we investigated the effect of the presence and density of visitors on the animals' behaviour and in the second, the effect of animal grooming by the visitors. We hypothesised that the animals' behaviour would be negatively affected by presence of visitors compared to periods of their absence, but this hypothesis was not fully supported by the data. Goat and llama behaviour was unaffected by the presence of the public, while the pigs showed decreased inactivity and social behaviour, both affiliative and aggressive, when visitors were present. All three study species exhibited increased levels of non-aggressive interaction with the public when visitor density was higher but the level of avoidance or aggression towards visitors was not dependent on density. The goats were less often in physical contact with other goats and less likely to be within proximity of a non-conspecific when visitor numbers were high, whereas the pigs showed decreased feeding, a behaviour that constituted a majority of their activity budget. Species differences were observed in the proportion of samples the study groups interacted in a non-aggressive manner with visitors, goats being most likely and llama the least likely to engage in this behaviour. In the second study visitors were provided with a grooming tool and asked to groom the animals, but no significant behavioural change was observed in either goats or pigs as a result. Visitors groomed goats, but not pigs, more than they interacted with them in non-grooming interactions, and goats, but not pigs, responded less to grooming as visitor density increased. Although significant behavioural changes in all three study species were associated with either visitor presence or density, the low levels of avoidance of visitors, visitor-directed aggression, or animal-directed aggression, suggest the welfare of the study animals was not profoundly impacted by visitor-related stimuli. Furthermore, there was no evidence that grooming by the public was enriching for the animals. The species differences reported here do suggest, however, that Vietnamese pot-bellied pigs and llama are more sensitive to visitor pressure than goats and particular attention to their welfare may be necessary when they are housed in petting zoo displays

    Effects of perchlorate on the molecules of excitation-contraction coupling of skeletal and cardiac muscle

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    To understand the nature of the transmission process of excitation- contraction (EC) coupling, the effects of the anion perchlorate were investigated on the voltage sensor (dihydropyridine receptor, DHPR) and the Ca release channel (ryanodine receptor, RyR) of the sarcoplasmic reticulum (SR). The molecules, from rabbit skeletal muscle, were either separated in membrane vesicular fractions or biochemically purified so that the normal EC coupling interaction was prevented. Additionally, the effect of ClO4- was investigated on L-type Ca2+ channel gating currents of guinea pig ventricular myocytes, as a native DHPR not in the physiological interaction of skeletal muscle. At 20 mM, ClO4- had minor effects on the activation of ionic currents through Ca channels from skeletal muscle transverse tubular (T) membranes fused with planar bilayers: a +7-mV shift in the midpoint voltage, V, with no change in kinetics of activation or deactivation. This is in contrast with the larger, negative shift that ClO4- causes on the distribution of intramembrane charge movement of skeletal muscle. At up to 100 mM it did not affect the binding of the DHP [3H]PN200-110 to triad-enriched membrane fractions (TR). At 8 mM it did not affect the kinetics or the voltage distribution of gating currents of Ca channels in heart myocytes. These negative results were in contrast to the effects of ClO4- on the release channel. At 20 mM it increased several-fold the open probability of channels from purified RyR incorporated in planar bilayers and conducting Ba2+, an effect seen on channels first closed by chelation of Ca2+ or by the presence of Mg2+. It significantly increased the initial rate of efflux of 45Ca2+ from TR vesicles (by a factor of 1.75 at 20 mM and 4.5 at 100 mM). ClO4- also increased the binding of [3H]ryanodine to TR fractions. The relative increase in binding was 50-fold at the lowest [Ca2+] used (1 microM) and then decayed to much lower values as [Ca2+] was increased. The increase was due entirely to an increase in the association rate constant of ryanodine binding. The chaotropic ions SCN- and I- increased the association rate constant to a similar extent. The binding of ryanodine to purified RyR protein reconstituted into liposomes had a greater affinity than to TR fractions but was similarly enhanced by ClO4-. The reducing agent dithiothreitol (5 mM) did not reduce the effect of ClO4- , and 5% polyethylene glycol, with an osmolarity equivalent to 20 mM ClO4-, did not change ryanodine binding.(ABSTRACT TRUNCATED AT 400 WORDS
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