Examination of central nervous system by functional observation battery after massive intravenous infusion of carbon monoxide-bound and oxygen-bound hemoglobin vesicles in rats.

Carbon monoxide (CO) is known as a toxic gas inducing "CO poisoning", which acutely affects the central nervous system (CNS) and which persistently affects brain functions depending on the exposure time and CO concentration. By contrast, in pathological rodent models, intravenous infusion of CO-bound hemoglobin vesicles (CO-HbV) has shown various beneficial effects such as anti-oxidative and anti-inflammatory reactions. This study assessed effects of CO-HbV infusion on CNS using a functional observation battery, sensory reflexes, grip strength, and landing foot splay measurements. The test fluids were CO-HbV and O2-bound HbV (O2-HbV) suspended in saline ([Hb] â€‹= â€‹10 â€‹g/dL), and saline alone for comparison. The rats received either 16 or 32 â€‹mL/kg of fluid intravenously at 1.5 â€‹mL/min/kg. Observations were made before infusion, and at 5 â€‹min, 4, 8, 24, 48 and 72 â€‹h after infusion. Massive doses of 16 and 32 â€‹mL/kg respectively corresponded to about 29 and 57% of the whole circulating blood volume (56 â€‹mL/kg). No toxicological effect was observed in any measurement item for any group in comparison to the control saline infusion group. Histopathological examination of hippocampal tissue at 14 days after infusion showed the number of necrotic cells to be minimal. Results obtained from rats in this experiment suggest that the massive intravenous infusion of CO-HbV yields beneficial anti-oxidative and anti-inflammatory effects without showing CO-poisoning-related symptoms of CNS damage.

Effect of carbon monoxide administration using haemoglobin-vesicles on the hippocampal tissue.

Carbon monoxide (CO) is a toxic gas that causes neuropathy. However, CO is endogenously produced in small amounts showing various beneficial effects. We hypothesized that CO-bound haemoglobin-vesicle (HbV) administration would reduce cerebral ischaemia-reperfusion injury without causing neuropathy. Three experiments were conducted. First, rats were exposed to CO inhalation to create a CO-poisoning group, and they were sacrificed on 0, 7, 14, and 21 days after CO exposure. Histopathologically, hippocampal damage was prominent at 14 days. Second, the rats were administered with CO-HbV equivalent to 50 or 25% of circulating blood volume (CO-HbV50 or CO-HbV25 group). Rats were sacrificed 14 days after administration. Third, rats put into haemorrhagic shock by 50% of circulating blood withdrawal were resuscitated using saline, autologous blood, and CO-HbV. They were sacrificed 14 days after resuscitation. Hippocampal damage assessment clarified that almost no necrotic cells were observed in the CO-HbV50 group. Necrotic cells in the CO-HbV25 group were comparable to those found for the control group. In rats resuscitated from haemorrhagic shock, the hippocampal damage in the group using CO-HbV was the mildest. Administration of CO-HbV did not lead to marked hippocampal damage. Furthermore, CO-HbV was effective at preventing cerebral ischaemia-reperfusion injury after haemorrhagic shock.

Translational Research of Hemoglobin Vesicles as a Transfusion Alternative.

Clinical situations arise in which blood for transfusion becomes scarce or unavailable. Considerable demand for a transfusion alternative persists because of various difficulties posed by blood donation and transfusion systems. Hemoglobin-vesicles (Hb- V) are artificial oxygen carriers being developed for use as a transfusion alternative. Just as biomembranes of red blood cells (RBCs) do, phospholipid vesicles (liposomes) for Hb encapsulation can protect the human body from the toxic effects of molecular Hb. The main HbV component, Hb, is obtained from discarded human donated blood. Therefore, HbV can be categorized as a biologic agent targeting oxygen for peripheral tissues. The purification procedure strictly eliminates the possibility of viral contamination. It also removes all concomitant unstable enzymes present in RBC for utmost safety from infection. The deoxygenated HbVs, which are storable for over the years at ambient temperature, can function as an alternative to blood transfusion for resuscitation from hemorrhagic shock and O2 therapeutics. Moreover, a recent study clarified beneficial effects for anti- oxidation and anti-inflammation by carbon monoxide (CO)-bound HbVs. Autoxidation of HbV (HbO2 → metHb + O2 -.) is unavoidable after intravenous administration. Co-injection of methylene blue can extract the intraerythrocytic glycolytic electron energy effectively and reduce metHb. Other phenothiazine dyes can also function as electron mediators to improve the functional life span of HbV. This review paper summarizes recent progress of the research and development of HbV, aimed at clinical applications.

Anesthesia-related care dissatisfaction: a cohort historical study to reveal related risks.

BACKGROUND: Most previous reports have used questionnaires to investigate patient satisfaction regarding anesthesia-related care. We retrospectively investigated the dissatisfaction rate for anesthesia and the contributing factors for it using a questionnaire including anesthesia-related adverse events and a simplified patient satisfaction scale. METHODS: This is a retrospective review of an institutional registry containing 21,606 anesthesia cases. We conducted multivariate logistic analysis in 9,429 patients using the incidence of dissatisfaction as a dependent variable and other covariates, including items of anesthesia registry and a postoperative questionnaire, as independent variables to investigate factors significantly associated with the risk of dissatisfaction with anesthesia. RESULTS: In the study population, 549 patients rated the anesthesia service as dissatisfactory. Multivariate analysis identified the preoperative presence of coexisting disease [odds ratio (OR), 1.29; 95% confidence interval (CI), 1.05-1.59], combination of regional anesthesia (OR, 1.44; 95% CI, 1.10-1.88), self-reported awareness (OR, 1.99; 95% CI, 1.29-3.06), postoperative nausea and vomiting (PONV) (OR, 1.54; 95% CI, 1.25-1.90), occurrence of nightmares (OR, 1.96; 95% CI, 1.52-2.53), and the number of days taken to visit a postoperative anesthesia consultation clinic (OR, 1.01; 95% CI, 1.00-1.02) to be independently associated with dissatisfaction with anesthesia service. CONCLUSIONS: Patients with coexisting disease, undergoing a combination of regional anesthesia, with self-reported awareness, experiencing PONV, suffering from nightmares, and who took longer to visit a postoperative anesthesia consultation clinic tended to rate our anesthesia service as dissatisfactory. Although the exact reasons for the factors contributing to dissatisfaction are unknown, this study suggests that there is room to improve our service.

A novel technique for ultrasound-guided central venous catheterization under short-axis out-of-plane approach: "stepwise flashing with triangulation".

In ultrasound-guided central venous catheterization, there is no standard technique either for the needle tip visualization or for the adequate needle angle and entry to the skin with short-axis view under out-of-plane technique. In the present study, we propose a novel technique named "stepwise flashing with triangulation", and the efficacy of this technique is assessed. Before and after a didactic session in which the technique was explained, 12 novice residents were asked to position the needle tip on or into the imitation vessels and to avoid deeper penetration by using an agar tissue phantom with ultrasound guidance. "Stepwise flashing" technique was for stepwise visualization of the needle tip, and "triangulation" technique was for adequate needle angle and entry to the skin. After the session, the success rate was increased and a deeper penetration rate was decreased. This technique will help us to facilitate vascular access and to avoid complications in clinical settings.