The effects of tramadol on postoperative shivering after sevoflurane and remifentanil anesthesia

Abstract Backgrounds Remifentanil has been reported to cause post-anesthetic shivering (PAS). Higher doses of remifentanil reportedly induce more intense PAS. Tramadol, a synthetic opioid that acts at multiple sites, is considered to be an effective treatment for PAS, but the evidence for its therapeutic benefit after remifentanil anesthesia is limited. We investigated the effect of tramadol on the incidence of PAS after remifentanil anesthesia. Methods Sixty-three patients who had undergone upper abdominal surgery under general anesthesia were studied retrospectively. Tramadol was administered at induction of anesthesia. The patients were divided into four groups: HT(+), high dose remifentanil (1\u20131.5\ua0\u3bcg/kg/min) with tramadol; HT(\u2212), high dose remifentanil without tramadol; LT(+), low dose remifentanil (0.15\u20130.25\ua0\u3bcg/kg/min) with tramadol; and LT(\u2212), low dose remifentanil without tramadol. We recorded perioperative changes in nasopharyngeal temperature and episodes of PAS on emergence from anesthesia. Results The incidences of PAS in both tramadol treatment groups were significantly lower than the groups that did not receive tramadol. Nasopharyngeal temperature after surgery fell significantly more from baseline in the tramadol treatment groups compared with the non-treatment groups. Conclusion Tramadol administered at induction of anesthesia appears to suppress PAS following remifentanil anesthesia

1-kHz high-frequency spinal cord stimulation alleviates chronic refractory pain after spinal cord injury: a case report

Abstract Background Patients with spinal cord injury (SCI) frequently complain of intractable pain that is resistant to conservative treatments. Here, we report the successful application of 1-kHz high-frequency spinal cord stimulation (SCS) in a patient with refractory neuropathic pain secondary to SCI. Case presentation A 69-year-old male diagnosed with SCI (C4 American Spinal Injury Association Impairment Scale A) presented with severe at-level bilateral upper extremity neuropathic pain. Temporary improvement in his symptoms with a nerve block implied peripheral component involvement. The patient received SCS, and though the tip of the leads could not reach the cervical vertebrae, a 1-kHz frequency stimulus relieved the intractable pain. Conclusions SCI-related symptoms may include peripheral components; SCS may have a considerable effect on intractable pain. Even when the SCS electrode lead cannot be positioned in the target area, 1-kHz high-frequency SCS may still produce positive effects

Effects of preoperative plasma exchange therapy with albumin replacement fluid on blood coagulation in patients undergoing ABO-incompatible living-donor kidney transplantation using rotational thromboelastometry

Abstract Background ABO-incompatible living-donor kidney transplantation (LDKT) requires immunotherapy and plasma exchange therapy (PEX). PEX with albumin replacement fluid reportedly decreases fibrinogen levels. However, no reports have described the effects of PEX with albumin replacement fluid on blood coagulation parameters and blood loss during the perioperative period. Therefore, we investigated the effects of preoperative PEX on blood coagulation parameters and blood loss during the perioperative period in patients undergoing ABO-incompatible LDKT as measured by rotational thromboelastometry (ROTEM®). Methods Twenty-eight patients undergoing LDKT were divided into the PEX group (ABO incompatible with PEX, n = 13) and non-PEX group (ABO compatible without PEX, n = 15). ROTEM® parameters, standard laboratory test parameters, bleeding volume, and transfusion volume were compared between PEX and non-PEX group. MCEplatelet, which represents platelet contribution to clot strength and where “MCE” stands for maximum clot elasticity, was calculated from the difference in MCE between EXTEM and FIBTEM. Results The bleeding volume during surgery and the intensive care unit (ICU) stay was significantly higher in the PEX than non-PEX group (p < 0.01). Maximum clot firmness (MCF) of EXTEM (MCFEXTEM), MCFFIBTEM, and MCEplatelet was significantly lower in the PEX than non-PEX group (p < 0.01). In the PEX group, the bleeding volume during surgery was very strongly correlated with the baseline MCFEXTEM and MCEplatelet, and the bleeding volume during the ICU stay was strongly correlated with the postoperative MCFEXTEM and MCEplatelet. Conclusions These results suggest that the increased blood loss in the PEX group during surgery and the ICU stay was associated with decreased platelet contribution to clot strength as measured by ROTEM®. Trial registration UMIN-Clinical Trial Registry UMIN000018355. Registered 21 July 2015

Thiosulfate Mediates Cytoprotective Effects of Hydrogen Sulfide Against Neuronal Ischemia

Background: Hydrogen sulfide (H2S) exhibits protective effects in various disease models including cerebral ischemia–reperfusion (I/R) injury. Nonetheless, mechanisms and identity of molecules responsible for neuroprotective effects of H2S remain incompletely defined. In the current study, we observed that thiosulfate, an oxidation product of H2S, mediates protective effects of an H2S donor compound sodium sulfide (Na2S) against neuronal I/R injury. Methods and Results: We observed that thiosulfate in cell culture medium is not only required but also sufficient to mediate cytoprotective effects of Na2S against oxygen glucose deprivation and reoxygenation of human neuroblastoma cell line (SH‐SY5Y) and murine primary cortical neurons. Systemic administration of sodium thiosulfate (STS) improved survival and neurological function of mice subjected to global cerebral I/R injury. Beneficial effects of STS, as well as Na2S, were associated with marked increase of thiosulfate, but not H2S, in plasma and brain tissues. These results suggest that thiosulfate is a circulating “carrier” molecule of beneficial effects of H2S. Protective effects of thiosulfate were associated with inhibition of caspase‐3 activity by persulfidation at Cys163 in caspase‐3. We discovered that an SLC13 family protein, sodium sulfate cotransporter 2 (SLC13A4, NaS‐2), facilitates transport of thiosulfate, but not sulfide, across the cell membrane, regulating intracellular concentrations and thus mediating cytoprotective effects of Na2S and STS. Conclusions: The protective effects of H2S are mediated by thiosulfate that is transported across cell membrane by NaS‐2 and exerts antiapoptotic effects via persulfidation of caspase‐3. Given the established safety track record, thiosulfate may be therapeutic against ischemic brain injury