Laboratory animals
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The aim of this study was to investigate the severity and duration of postoperative pain and hyperalgesia in sheep undergoing mandibular reconstructive surgery. Stimulus-evoked sensitivity at the surgical site and an area remote from injury, the ipsilateral and contralateral forelimbs, was measured as objective indicators of altered pain processing in adult female sheep (n = 7). Responses were recorded before surgery and one, two, three, seven and 14 days afterwards. ⋯ A significant decrease in forelimb mechanical withdrawal thresholds (secondary hyperalgesia) and response thresholds to punctate stimulation of the area surrounding the surgical incision (allodynia) was detected one day after surgery and persisted for at least three days, despite intra- and postoperative analgesic treatment. Concentrations of haptoglobin were significantly increased one day post-surgery, indicating the presence of a significant acute inflammatory response, and returned to pre-surgical concentrations by seven days. These data provide a deeper insight into understanding the impact of surgery in experimental animals, and may assist in formulating more effective analgesic and antihyperalgesic treatment regimens postoperatively.
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The combination of propofol and a rapid-acting opioid, such as fentanyl, sufentanil or remifentanil, is a relatively safe, total intravenous anaesthesia technique, commonly used in humans and which has been investigated in laboratory animals. The objective of this study was to evaluate these combinations for anaesthesia of mice by the intraperitoneal (i.p.) route. Sixty-seven mice, divided into groups of four, were used to test 28 combinations of propofol alone and propofol with fentanyl, sufentanil or remifentanil administered i.p. ⋯ Higher opioid doses induced respiratory depression and higher death rates. The inconsistency between and within groups may be associated with the i.p. route. The results reported here show that the i.p. route is not appropriate for mouse anaesthesia using propofol alone or in combination with fentanyl, sufentanil or remifentanil.
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Sudden cardiac death (SCD) is a field of continuous research. In order to answer various questions regarding SCD, several animal models have been developed. The aim of the present study is to describe our experimental model of inducing cardiac arrest in Landrace/Large White pigs, and then resuscitated according to the International Guidelines on resuscitation. ⋯ Successful resuscitation was contingent on the restoration of the levels of coronary perfusion pressure and PETCO(2) during chest compressions. Among the different ways of inducing cardiac arrest, the ordinary lithium battery is a simple, safe and valuable technique. Landrace/Large White pigs' baseline haemodynamics closely resemble human haemodynamics, making the breed a favourable model for resuscitation.
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The objective of the study was to evaluate the effects of ketamine on intestinal microcirculation in pentobarbital-anaesthetized rats during experimental endotoxaemia. A prospective, randomized, controlled study was carried out using 32 male Lewis rats. The animals were divided into four groups (n = 8 each). ⋯ The addition of ketamine to pentobarbital anaesthesia did not significantly affect FCD, leukocyte behaviour or cytokine levels. In conclusion, intravenous pentobarbital anaesthesia with the additional administration of ketamine did not cause alterations within the microcirculation or changes in cytokine release during endotoxaemia. In rats, the combination of pentobarbital and ketamine is suitable for use during the study of intestinal microcirculation in experimental endotoxaemia.
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The feasibility of an anaesthetic protocol developed for surgery during right heart bypass in sheep is reported. Seven female Suffolk sheep, weighing 25-35 kg, were selected for the study. Premedication consisted of midazolam and methadone (both 0.1 mg kg(-1) intravenously). ⋯ Decreases in blood pressure at the beginning of the bypass can be expected and require treatment. Nitrates are useful in avoiding volume overload during weaning. The anaesthetic protocol is acceptable for surgery under right heart bypass in sheep.