Shen-Chih Wang

Thromboelastography-guided transfusion decreases intraoperative blood transfusion during orthotopic liver transplantation: randomized clinical trial.

OBJECTIVE To test in a prospective randomized study the hypothesis that use of thromboelastography (TEG) decreases blood transfusion during major surgery. MATERIAL AND METHODS Twenty-eight patients undergoing orthotopic liver transplantation were recruited over 2 years. Patients were randomized into 2 groups: those monitored during surgery using point-of-care TEG analysis, and those monitored using standard laboratory measures of blood coagulation. Specific trigger points for transfusion were established in each group. RESULTS In patients monitored via TEG, significantly less fresh-frozen plasma was used (mean [SD], 12.8 [7.0] units vs 21.5 [12.7] units). There was a trend toward less blood loss in the TEG-monitored patients; however, the difference was not significant. There were no differences in total fluid administration and 3-year survival. CONCLUSION Thromboelastography-guided transfusion decreases transfusion of fresh- frozen plasma in patients undergoing orthotopic liver transplantation, but does not affect 3-year survival.

Use of higher thromboelastogram transfusion values is not associated with greater blood loss in liver transplant surgery

Plasma‐containing products are given during the pre‐anhepatic stage of liver transplant surgery to correct abnormal thromboelastogram (TEG) values and prevent blood loss due to coagulation defects. However, evidence suggests that abnormal TEG results do not always predict bleeding. We questioned what effect using higher TEG values to initiate treatment would have on blood loss. A single transfusion protocol was used for all patients who underwent liver transplantation between 2007 and 2010. Thirty‐eight patients received coagulation products when standard TEG cutoff values were exceeded, whereas another 39 patients received coagulation products when the TEG values were 35% greater than normal. The results of postoperative coagulation tests for total blood loss and the use of blood products were compared for the 2 groups. When the critical TEG values for transfusion were higher, significantly fewer units of fresh frozen plasma (5.58 ± 6.49 versus 11.53 ± 6.66 U) and pheresis platelets (1.84 ± 1.33 versus 3.55 ± 1.43 U) were used. There were no differences in blood loss or postoperative blood product use. In conclusion, the use of higher critical TEG values to initiate the transfusion of plasma‐containing products is not associated with increased blood loss. Further testing is necessary to identify what TEG value predicts bleeding due to a deficit in coagulation factors. Liver Transpl 18:1254–1258, 2012.

Fluid management guided by stroke volume variation failed to decrease the incidence of acute kidney injury, 30-day mortality, and 1-year survival in living donor liver transplant recipients.

Background: Low central venous pressure (CVP) produced by fluid restriction has been applied to liver transplant recipients in order to decrease blood loss. However, CVP is not reliable for monitoring intravascular volume and ventricular filling. In addition, doubts remain over the association between fluid restriction and acute kidney injury (AKI). We tested the utility of stroke volume variation (SVV), derived from the FloTrac/Vigileo system, as a decision‐making tool in fluid management. We examined the differences in fluid administration, urine output, postoperative AKI, and 30‐day and 1‐year survival rates between liver transplant recipients with fluid management guided by SVV and CVP. Methods: We retrospectively collected data on our liver transplant recipients with a Model for End‐stage Liver Disease score less than 30 and serum creatinine lower than 1.5 mg/dL from 2007 to 2010. Recipients in 2007 and 2008 who received CVP‐guided fluid management served as the control group. Recipients in 2009 and 2010 who received fluid administration triggered by SVV were recruited as the study group. The estimated blood loss, urine output, and fluid administered during the operation were recorded. Renal function was assessed using the RIFLE criteria on postoperative days 1 and 5. We also recorded the 30‐day and 1‐year survival. Results: Significantly more diuretic use and urine output were noted in the control group in spite of similar fluid administration. However, there was no significant difference in blood loss, AKI, or 30‐day and 1‐year survival rates. Conclusion: The outcomes of living donor liver transplant patients who had fluid therapy guided by an SVV less than 10% were similar to those of patients who were given fluids to reach a CVP of 10 mmHg. Our findings suggest that the two measures of vascular filling are similar in liver transplant recipients with demographic characteristics similar to those of our patients.

MicroRNA-92a Mediates Endothelial Dysfunction in CKD

CKD is an independent risk factor for cardiovascular disease (CVD). The accumulation of uremic toxins in CKD induces oxidative stress and endothelial dysfunction. MicroRNA-92a (miR-92a) is induced by oxidative stress in endothelial cells (ECs) and involved in angiogenesis and atherosclerosis. We investigated a role for oxidative stress-responsive miR-92a in CKD. Our study of patients at three clinical sites showed increased serum miR-92a level with decreased kidney function. In cultured ECs, human CKD serum or uremic toxins (such as indoxyl sulfate), compared with non-CKD serum, induced the levels of miR-92a and suppressed the expression of miR-92a targets, including key endothelial-protective molecules. The antioxidant N-acetylcysteine inhibited these vasculopathic properties. In rats, adenine-induced CKD associated with increased levels of miR-92a in aortas, serum, and CD144+ endothelial microparticles. Furthermore, CD144+ microparticles from human uremic serum contained more miR-92a than those from control serum. Additional analysis showed a positive correlation between serum levels of miR-92a and indoxyl sulfate in a cohort of patients with ESRD undergoing hemodialysis. Collectively, our findings suggest that the uremic toxins accumulated in CKD can upregulate miR-92a in ECs, which impairs EC function and predisposes patients to CVD.

Spontaneous Intracranial Hypotension Treated by Epidural Blood Patches

We present a case of spontaneous intracranial hypotension (SIH) diagnosed from the clinical symptoms and magnetic resonance imaging brain scans. After failure of conservative treatment, and lack of identification of the cerebrospinal fluid leak site, the headache was managed successfully and simply with two applications of an epidural blood patch (EBP). The strategy of our management for the patient was as follows: (1) application of an EBP to the lumbar epidural space initially and manipulating it into the proximity of the possible leak site; (2) a greater volume of autologous blood was injected at the second attempt of EBP; and (3) the patient was required to lie flat for at least 2 hours after the procedure. Better management of SIH is still developing. Traditionally, SIH is initially managed by conservative treatment. However, recent studies have shown that the success rate in arresting SIH after weeks or months of conservative treatment is not quite satisfactory. Hence, the EBP has proven to be more effective in treating SIH patients. Early EBP application may offer immediate relief of clinical symptoms. The role of the EBP in treating SIH patients should have greater emphasis and its application is worth recommendation.

Comparison of three different concentrations of ropivacaine for postoperative patient-controlled thoracic epidural analgesia after upper abdominal surgery.

BACKGROUND Previous studies have reported the comparable efficacy of ropivacaine/fentanyl for patient-controlled epidural analgesia (PCEA). In our hospital, three different concentrations of ropivacaine solution (0.1%, 0.15%, 0.2%) in combination with 1 microg/mL fentanyl were available for PCEA. As some studies have reported a much higher incidence of motor block and opioid-related side effects with 0.2% ropivacaine in combination with 4 microg/mL fentanyl, it was our intent to analyze the data of our patients who had received PCEA after upper abdominal surgery. In addition to comparing the analgesic effects and the incidence of motor block and opioid-related side effects of these three different ropivacaine/fentanyl solutions, we also evaluated the workload of our pain staff. The main purpose of our study was to determine which of these three regimens of ropivacaine was most satisfactory with the least workload for the pain service staff. METHODS In total, 33 patients who had received PCEA after upper abdominal surgery were included in the analysis. The number of patients in each ropivacaine/fentanyl group was 11 (group 1, 0.1% ropivacaine; group 2, 0.15%; group 3, 0.2%). The PCEA device was programmed to deliver a patient-controlled bolus of 2 mL with a lockout time of 20 minutes and background infusion of 5 mL/hr for 72 hours. Visual analog scale (VAS) pain scores, adverse events and the extent of sensory or motor block were recorded 12, 36 and 60 hours after surgery. The total volume of analgesic solution consumed and the frequency of requisite attendance by pain service staff were also recorded. RESULTS There were no differences among the three groups regarding total consumption. In group 1, VAS scores during ambulation and cough 12 hours postoperatively were significantly higher than in the other two groups (p < 0.05). There was no motor block. Four patients in group 3 suffered from loss of temperature sensation. The overall incidence of adverse events was less than 40%. CONCLUSION Both thoracic epidural 0.15% and 0.2% ropivacaine provide effective postoperative pain control in combination with fentanyl without motor block. A 0.15% ropivacaine-1 microg/mL fentanyl solution is preferable considering the lower incidence of adverse events.

Increased requirement for minute ventilation and negative arterial to end-tidal carbon dioxide gradient may indicate malignant hyperthermia

Characteristic signs of malignant hyperthermia (MH) include unexplained tachycardia, increased end-tidal carbon dioxide (Etco₂) concentration, metabolic and respiratory acidosis, and an increase in body temperature above 38.8°C. We present the case of a patient with highly probable MH. In addition to sinus tachycardia and metabolic and respiratory acidosis, this patient also had a negative arterial to Etco₂ gradient and an increased requirement for minute ventilation to maintain a normal Etco₂ concentration, with signs of increased CO₂ production. Despite these signs of MH, the patients rectal temperature monitoring equipment did not show an increase in temperature, although the temperature measured in the mouth was increased. This case illustrates the unreliability of measuring rectal temperature as a means of reflecting body temperature during MH and the usefulness of increased CO₂ production signs in helping to diagnose MH.

Retrograde arterial flush of the liver graft in living donor liver transplantation may ameliorate post-transplantational cholestasis – a prospective randomized study

Liu C, Loong C‐C, Hsia C‐Y, Wang S‐C, Yeh Y‐C, Lin N‐C, Tsai H‐L, Tsou M‐Y. Retrograde arterial flush of the liver graft in living donor liver transplantation may ameliorate post‐transplantational cholestasis – a prospective randomized study. 
Clin Transplant 2011 DOI: 10.1111/j.1399‐0012.2011.01493.x. 
© 2011 John Wiley & Sons A/S.

Innominate artery dissection with presentation of sudden right frontal desaturation detected by cerebral oximetry in complicated thoracic aortic aneurysm repair surgery: a case report

Cerebral oximetry is a noninvasive bedside monitor for cerebral oxygen saturation (rSO(2)). A patient with a thoracic aneurysm underwent combined surgical and endovascular repair. A sudden decrease in right rSO(2) led to the finding of acute innominate artery dissection. Immediate repair was instituted. Sudden asymmetry of rSO(2) may be a warning sign of underlying pathology.

Reply: To PMID 23245482.

Thank you for Dr. Hung’s response to our newly published paper. We have reanalyzed our data in Table 4 using the ManneWhitney U test. There was still no significant association between our fluid management and acute kidney injury ( p 1⁄4 0.157). We also pooled the groups of risk, injury and failure patients into a single category for the c test. No significant association was found between different methods of fluid management ( p 1⁄4 0.182). Therefore, our findings are consistent regardless of statistical methods. Additionally, this paper was supervised by an accredited expert and author in statistics, who also passed the statistical evaluation to be a statistical editor for JCMA. Therefore, we have confidence that the findings we have presented are reliable.