Physiological research
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Physiological research · Jan 2012
Comparative StudyComparison of the effects of ketamine-dexmedetomidine and sevoflurane-sufentanil anesthesia on cardiac biomarkers after cardiac surgery: an observational study.
Inhalational anesthetics have demonstrated cardioprotective effects against myocardial ischemia-reperfusion injury. Clinical studies in cardiac surgery have supported these findings, although not with the consistency demonstrated in experimental studies. Recent investigations have questioned the advantages of inhalational over intravenous anesthetics with respect to cardiac protection. ⋯ Compared with the SEVO group, the KET-DEX group exhibited significantly reduced cardiac troponin I (2.22+/-1.73 vs. 3.63+/-2.37 microg/l; P=0.02) and myocardial fraction of creatine kinase (CK-MB) levels (12.4+/-10.4 vs. 20.3+/-11.2 microg/l; P=0.01) on the morning of the first postoperative day. Furthermore, cardiac troponin I release, evaluated as the area under the curve, was significantly reduced in the KET-DEX group (32.1+/-20.1 vs. 50.6+/-23.2; P=0.01). These results demonstrate the cardioprotective effects of ketamine-dexmedetomidine anesthesia compared with those of sevoflurane-sufentanil anesthesia.
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Physiological research · Jan 2012
Changes in hind paw epidermal thickness, peripheral nerve distribution and mechanical sensitivity after immobilization in rats.
This study was designed to investigate histological changes in skin tissue accompanying immobilization-induced hypersensitivity. Changes in mechanical sensitivity, epidermal thickness, and peripheral nerve profiles in the upper dermis were examined in glabrous skin of rat hind paw after 1, 2, and 4 weeks of ankle joint immobilization by plaster casts. ⋯ The time course of epidermal thinning and increase in peripheral nerve profiles were similar closely to that of hypersensitivity, with significant differences between the immobilized and control rats after 2 weeks of immobilization, which became even more remarkable at 4 weeks of immobilization. These findings suggest that joint immobilization by cast induces epidermal thinning and increases peripheral nerve profiles in the upper dermis and that these changes might be partly responsible for immobilization-induced hypersensitivity.
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Physiological research · Jan 2011
Neurogenic pulmonary edema induced by spinal cord injury in spontaneously hypertensive and Dahl salt hypertensive rats.
Neurogenic pulmonary edema (NPE), which is induced by acute spinal cord compression (SCC) under the mild (1.5 %) isoflurane anesthesia, is highly dependent on baroreflex-mediated bradycardia because a deeper (3 %) isoflurane anesthesia or atropine pretreatment completely abolished bradycardia occurrence and NPE development in rats subjected to SCC. The aim of the present study was to evaluate whether hypertension-associated impairment of baroreflex sensitivity might exert some protection against NPE development in hypertensive animals. ⋯ SCC elicited NPE in both hypertensive models irrespective of their baroreflex sensitivity. It is evident that a moderate impairment of baroreflex sensitivity, which was demonstrated in salt hypertensive Dahl rats, does not exert sufficient protective effects against NPE development.
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Physiological research · Jan 2011
In situ assessment of the brain microcirculation in mechanically-ventilated rabbits using sidestream dark-field (SDF) imaging.
Assessment of the cerebral microcirculation by on-line visualization has been impossible for a long time. Sidestream dark-field (SDF) imaging is a relatively new method allowing direct visualization of cerebral surface layer microcirculation using hand-held probe for direct contact with target tissue. The aim of this study was to elucidate the feasibility of studying the cerebral microcirculation in situ by SDF imaging and to assess the basic cerebral microcirculatory parameters in mechanically ventilated rabbits. ⋯ Clear high contrast SDF images were successfully obtained. Total small-vessel density was 14.6+/-1.8 mm/mm(2), total all-vessel density was 17.9+/-1.7 mm/mm(2), DeBacker score was 12.0+/-1.6 mm(-1) and microvascular flow index was 3.0+/-0.0. This method seems to be applicable in animal studies with possibility to use SDF imaging also intraoperatively, providing unique opportunity to study cerebral microcirculation during various experimental and clinical settings.
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Physiological research · Jan 2011
Randomized Controlled Trial Comparative StudyBiomarkers of oxidative stress and endothelial dysfunction after tourniquet release in children.
Pneumatic tourniquets are widely used in pediatric extremity surgery to provide a bloodless field and facilitate dissection. This prospective study was carried out to examine possible effect of different anesthesia techniques on oxidative stress and endothelial dysfunction connected with ischemia-reperfusion injury during extremity operations at children's age. ⋯ Venous blood samples for determination of the malondialdehyde in plasma and erythrocytes, protein carbonyl groups concentration as well as plasma nitrites and nitrates level and xanthine oxidase activity were obtained at four time points: before peripheral nerve block and induction of general anesthesia (baseline), 1 min before tourniquet release, 5 and 20 min after tourniquet release. This study demonstrates that total intravenous anesthesia with propofol and regional anesthesia techniques provide better antioxidant defense and reduce endothelial dysfunction than general inhalational anesthesia with sevoflurane during tourniquet application in pediatric extremity surgery.