Arterial oxygen pressure during veno-venous extracorporeal membrane oxygenation may be increased by advancing the tip of the drainage cannula into the superior vena cava: a case report.

A simple and robust method for veno-venous extracorporeal membrane oxygenation (V-V ECMO) involves a drainage cannula into the inferior vena cava via the femoral vein (FV) and a reinfusion cannula into the right atrium (RA) via the internal jugular vein (IJV) (F-J configuration). However, with this method, the arterial oxygen (PaO2) is said to remain below 100 mmHg.Since recently, in our ICU, to prevent drainage failure, we apply a modification from the commonly practiced F-J configuration by advancing the tip of the drainage cannula inserted via the FV into the superior vena cava (SVC) and crossing the reinfusion cannula inserted via the IJV in the RA (F(SVC)-J(RA) configuration). We experienced that this modification can be associated with unexpectedly high PaO2 values, which here we investigated in detail.Veno-arteriovenous ECMO was induced in a 65-year-old male patient who suffered from repeated cardiac arrest due to acute respiratory distress syndrome. His chest X-ray images showed white-out after lung rest setting, consistent with near-absence of self-lung ventilation. Cardiac function recovered and the system was converted to F(SVC)-J(RA) configuration, after which both PaO2 and partial pressure of pulmonary arterial oxygen values remained high above 200 mmHg. Transesophageal echocardiography could not detect right-to-left shunt, and more efficient drainage of the native venous return flow compared to common F-J configuration may explain the increased PaO2.Although the F(SVC)-J(RA) configuration is a small modification of the F-J configuration, it seems to provide a revolutionary improvement in the ECMO field by combining robustness/simplicity with high PaO2 values.

Abnormal stenosis of a drainage cannula due to excessive negative pressure during venovenous extracorporeal membrane oxygenation management: a case report.

We report a case in which excessive negative pressure may have been applied to the proximal side hole of a drainage cannula during venovenous extracorporeal membrane oxygenation (V-V ECMO), resulting in abnormal stenosis of the drainage cannula. V-V ECMO was introduced in a 71-year-old male patient who was transferred from another hospital for severe respiratory failure associated with varicella pneumonia and acute respiratory distress syndrome. Drainage was performed using a PCKC-V™ 24Fr (MERA, Japan) cannula via the right femoral vein with the tip of the cannula near the level of the diaphragm under fluoroscopy. Reinfusion was performed via the right internal jugular vein. Due to poor systemic oxygenation, the drainage cannula was withdrawn caudally and refixed to reduce the effect of recirculation. Two days later, drainage pressure dropped rapidly, and frequent ECMO flow interruption occurred due to poor drainage. An abdominal X-ray revealed abnormal stenosis of the proximal side hole site of the drainage cannula. We diagnosed that the drainage cannula was damaged, and it was replaced with another, namely a Medtronic Bio-Medicus™ 25 Fr (GETINGE, Sweden) cannula. However, the removed drainage cannula was not damaged, suggesting that the cannula was temporarily stenosed by momentary excessive negative pressure. In a multi-stage drainage cannula, the main drainage site is the proximal side hole, with little negative pressure applied at the apical foramen in a mock experimental ex vivo drainage test in a water tank. Hence, improvement of a multi-stage drainage cannula is recommended, such as adequate reinforcement of the side hole site with a wire.

Investigation of factors affecting COVID-19 pancreatic injury: a single-center, retrospective study.

Pancreatic injury is considered an organ-related complication in patients with coronavirus disease 2019 (COVID-19). However, it is unclear whether COVID-19 status affects pancreatic injury. This retrospective study aimed to determine whether COVID-19 affects the occurrence of pancreatic injuries. Consecutive patients diagnosed with sepsis admitted to the ICU between March 2020 and September 2021 were included. The primary endpoint was a pancreatic injury, which was defined as amylase or lipase levels > 3 times the upper limit of the normal range. Among the 177 patients included in the analysis, 40 (23%) were COVID-19 patients, and 54 (31%) had pancreatic injuries. Of these three patients, acute pancreatitis was diagnosed based on computed tomography. The pancreatic injury was significantly more common among COVID-19 patients (75 vs. 18%, p < 0.001). Multivariate analysis showed that COVID-19 and steroid use were independent risk factors for pancreatic injury (Odds Ratio (OR) 4.79 [95% confidence interval (CI) 1.48-15.5], p = 0.009; OR 4.02 [95% CI 1.42-11.4], p = 0.009). This study revealed that the proportion of pancreatic injury in septic patients with COVID-19 was significantly higher than in those without COVID-19. It may be difficult to diagnose pancreatitis based on amylase and lipase levels in COVID-19 patients.

Perturbation of monoamine metabolism and enhanced fear responses in mice defective in the regeneration of tetrahydrobiopterin.

Increasing evidence suggests the involvement of peripheral amino acid metabolism in the pathophysiology of neuropsychiatric disorders, whereas the molecular mechanisms are largely unknown. Tetrahydrobiopterin (BH4) is a cofactor for enzymes that catalyze phenylalanine metabolism, monoamine synthesis, nitric oxide production, and lipid metabolism. BH4 is synthesized from guanosine triphosphate and regenerated by quinonoid dihydropteridine reductase (QDPR), which catalyzes the reduction of quinonoid dihydrobiopterin. We analyzed Qdpr-/- mice to elucidate the physiological significance of the regeneration of BH4. We found that the Qdpr-/- mice exhibited mild hyperphenylalaninemia and monoamine deficiency in the brain, despite the presence of substantial amounts of BH4 in the liver and brain. Hyperphenylalaninemia was ameliorated by exogenously administered BH4, and dietary phenylalanine restriction was effective for restoring the decreased monoamine contents in the brain of the Qdpr-/- mice, suggesting that monoamine deficiency was caused by the secondary effect of hyperphenylalaninemia. Immunohistochemical analysis showed that QDPR was primarily distributed in oligodendrocytes but hardly detectable in monoaminergic neurons in the brain. Finally, we performed a behavioral assessment using a test battery. The Qdpr-/- mice exhibited enhanced fear responses after electrical foot shock. Taken together, our data suggest that the perturbation of BH4 metabolism should affect brain monoamine levels through alterations in peripheral amino acid metabolism, and might contribute to the development of anxiety-related psychiatric disorders. Cover Image for this issue: https://doi.org/10.1111/jnc.15398.

Hyperchloremia and Postoperative Acute Kidney Injury in Adult Cardiac Patients: A Propensity-Matched Cohort Study.

OBJECTIVES: Hyperchloremia is a potential risk factor for acute kidney injury (AKI) in critically ill patients. However, the relationship between hyperchloremia and postoperative AKI in adult patients undergoing cardiovascular surgery with cardiopulmonary bypass (CPB) remains unclear. The authors aimed to determine whether postoperative hyperchloremia was associated with postoperative AKI in these populations. OBJECTIVES: Retrospective, single-center study. SETTING: Tertiary care hospital. PARTICIPANTS: Adult patients who underwent cardiovascular surgery with CPB. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients with and without postoperative hyperchloremia were matched (1:1). The primary outcome was the rate of postoperative AKI diagnosed using the Kidney Disease: Improving Global Outcomes consensus criteria. Postoperative hyperchloremia was defined as postoperative serum chloride levels of >110 mmol/L during the first 48 hours. An increase in serum chloride levels (Δ[Cl-]) was defined as the difference between the preoperative and maximum postoperative serum chloride levels during the first 48 hours ([Cl-]max). Propensity-score matching and univariate and multivariate logistic regression analyses were employed. A total of 323 patients were included. Propensity-score matching selected 55 pairs for the final comparison. The incidence of postoperative AKI did not differ between the two groups (47% v 46%, p = 1.0). In the multivariate logistic regression analysis, Δ[Cl-] was associated independently with the development of postoperative AKI (odds ratio, 1.13; 95% confidence interval, 1.06-1.21; p < 0.001). CONCLUSIONS: Exposure to postoperative hyperchloremia was not associated with postoperative AKI in adult patients undergoing cardiovascular surgery with CPB. However, an increase in the serum chloride level might be associated with postoperative AKI.

Current status of antimicrobial prophylaxis during extracorporeal membrane oxygenation in Japan: a national survey.

Infection during extracorporeal membrane oxygenation (ECMO) is a common complication that leads to increased mortality. Thus, antimicrobial prophylaxis during ECMO is often performed to prevent of nosocomial infections. However, the current status of antimicrobial prophylaxis during ECMO in Japan is unclear. Therefore, we conducted a national survey of members of the Japanese Society of Intensive Care Medicine (JSICM) to clarify the current status of antimicrobial prophylaxis during ECMO in intensive care units. An 11-question survey was devised to assess antimicrobial prophylaxis and surveillance practices during ECMO. A total of 253 hospitals responded. Of these, 235 hospitals were the JSICM-certified hospitals, and the response rate was 64%. A total of 96 hospitals (39%) administered antimicrobial prophylaxis during ECMO, and 17% of hospitals had a standardized protocol for antimicrobial prophylaxis during ECMO. Of these 96 hospitals, 79% used single agents. First-generation cephalosporins were the most commonly used (54%), followed by penicillins or penicillin-derived combinations (24%), second-generation cephalosporins (7%), and anti-methicillin-resistant Staphylococcus aureus agents (6%). In conclusion, our survey revealed 39% of hospitals administered antimicrobial prophylaxis during ECMO in Japan. First-generation cephalosporins were the agents most commonly used.

A case of spontaneous rectus sheath hematoma induced by lateral semi-prone positional changes during extracorporeal membrane oxygenation.

Spontaneous abdominal wall hematomas are relatively rare and mainly attributed to anticoagulation and severe cough. Despite the high incidence of anticoagulation-related bleeding complications, there are no reports of spontaneous abdominal wall hematomas during extracorporeal membrane oxygenation (ECMO). We report a case of a spontaneous rectus sheath hematoma caused by alternation of the lateral semi-prone position during ECMO in a 76-year-old female patient with severe acute respiratory distress syndrome. Unfractionated heparin 12,000-14,000 units/day was administered for anticoagulation during ECMO. From Day 6 of ECMO, the patient who was under deep sedation was alternately placed in the left and right lateral semi-prone positions every 4 h, for approximately 20 h per day. On Day 12 of ECMO, the patient developed hypotension with anemia and a palpable mass in the right lower abdomen. Abdominal ultrasonographic imaging revealed a huge echo-free space centered in the right lower abdomen. Emergency contrast-enhanced computed tomography (CT) scanning showed extravasation from the superior and inferior epigastric arteries as well as a rectus sheath hematoma. Despite no apparent contrast leakage, an inferior epigastric artery embolization was undertaken because the patient was on ECMO. On Day 13 after ECMO initiation, ECMO and anticoagulation were discontinued. On CT scanning a week later, the hematoma had reduced. In conclusion, spontaneous abdominal wall hematoma is a rare and important complication that might occur during ECMO. Thus, careful physical examination should be routinely conducted when the patient is semi-prone during ECMO.

In vitro Evaluation of Linezolid and Doripenem Clearance with Different Hemofilters.

INTRODUCTION: Renal replacement therapy (RRT) is widely used in the treatment of septic acute kidney injury. However, little is known about how the adsorption properties of hemofilters used in RRT affect antibiotic concentration. Because a cytokine-adsorption membrane is frequently used in RRT, it is important to determine the antibiotic adsorption capacity of this membrane. OBJECTIVE: The present study aimed to investigate the antibiotic adsorption capacity of different hemofilter membranes by in vitro experiments using 2 antibacterial agents (linezolid and doripenem). METHODS: We performed experimental hemofiltration in vitro using polyacrylonitrile (AN69ST), polymethylmethacrylate (PMMA), and polysulfone (PS) hemofilters for 1,440 min. The test solution was a 1,000-mL substitution fluid containing 30 µg/mL linezolid and 120 µg/mL doripenem. We measured drug concentrations at the inlet, outlet, and filtrate ports of the hemofilters for 1,440 min and calculated the sieving coefficient (SC) and adsorption rate (Ra) of the drugs onto the hemofilters. RESULTS: The amount of linezolid adsorbed onto AN69ST, PMMA, and PS membranes was decreased relative to that in the control group at 15 min (p < 0.05). However, no SC for linezolid was obtained thereafter. The Ra of linezolid onto AN69ST, PMMA, and PS membranes was higher than that in the control group (p < 0.05). In contrast, no significant differences were observed in the concentrations and Ra values of doripenem adsorbed onto AN69ST, PMMA, and PS membranes compared with those in the control group. CONCLUSIONS: Doripenem was not adsorbed onto PMMA, PS, and AN69ST membranes. Linezolid was adsorbed onto PMMA, PS, and AN69ST membranes, but only temporarily, and this did not affect drug bioavailability.

Differences in characteristics and outcomes between community- and hospital-acquired acute kidney injury: A systematic review and meta-analysis
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INTRODUCTION: No comprehensive review has examined the difference between community-acquired (CA) and hospital-acquired (HA) acute kidney injury (AKI) in terms of patient characteristics, in-hospital mortality, and hospital stay length. MATERIALS AND METHODS: We conducted a systematic review and meta-analysis of observational studies, using MEDLINE, EMBASE, Web of Science, Google Scholar, and the Cochrane Library from their inceptions to April 10, 2016. Observational studies that (1) were published in peer-reviewed journals; (2) compared CA-AKI with HA-AKI, irrespective of the AKI definition during the same period; and (3) investigated in-hospital mortality and length of hospital stay were studied. Differences in the patients' baseline characteristics were analyzed, and a meta-analysis was conducted to compare the in-hospital mortality and length of hospital stay. RESULTS: Eight eligible observational studies with 17,939 patients were included. The systematic review showed that patients with CA-AKI had a significantly higher rate of AKI stage 3 compared with those with HA-AKI. The meta-analysis revealed that patients with CA-AKI showed significantly lower in-hospital mortality (odds ratio (OR) = 2.79; Z = 8.22; 95% confidence interval (CI), 2.18 - 3.56; p < 0.001) and shorter length of hospital stay (OR = 2.55; Z = 5.81; 95% CI, 1.86 - 3.50; p < 0.001). Subanalyses of studies conducted in developing and developed countries showed that patients with CA-AKI had lower in-hospital mortality and shorter length of hospital stay. Jackknife sensitivity analyses confirmed the replicability of these findings (p < 0.001). CONCLUSIONS: The results indicate that significant differences exist in clinical phenotypes between CA- and HA-AKI, even when standardized diagnosis criteria are used.
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Histopathological comparison of the onset of peri-implantitis and periodontitis in rats.

BACKGROUND AND OBJECTIVE: There are a few experimental models that clearly describe the pathological differences in tissue destruction between periodontitis and peri-implantitis. We recently reported that the formation of immune complexes accelerates site-specific loss of attachment and alveolar bone resorption when an antigen is topically applied in the gingival sulcus of an immunized rat. We applied this model to the peri-implant tissues and compared peri-implant destruction to periodontitis without using a ligature. MATERIAL AND METHODS: Twenty-five rats were used in this study and were divided into five groups. Implantation was performed immediately after extraction of right first molars in rats. The left first molars were left untreated to be examined as natural teeth. The immunized group consisted of rats that had received intraperitoneal lipopolysaccharide (LPS), whereas the nonimmunized group received only phosphate-buffered saline (PBS). The untreated baseline group received only implantation. After intraperitoneal booster injection, half of each group received topical application of LPS in the palatal gingival sulcus daily for 3 days. The other half of the groups received PBS. Histopathological and histometrical findings were observed with hematoxylin and eosin staining, collagen fibers were observed with Azan staining, and formation of immune complexes was immunohistologically evaluated by C1qB expression. RESULT: Peri-implant tissue destruction was greater in the immunized and LPS-applied groups than in the other groups. No periodontal destruction was observed. Formation of immune complexes was observed in the junctional epithelium and adjacent connective tissue in the immunized groups. CONCLUSION: Antigen-induced peri-implant tissue destruction occurs faster than periodontal tissue destruction.

[Successful treatment with azacitidine for myelodysplastic syndrome with large vessel vasculitis].

Paraneoplastic inflammation of the large vessels is a rare complication of myelodysplastic syndrome (MDS), and patients with MDS and systemic vasculitis have a poor prognosis. We present a 66-year-old male with MDS and large vessel vasculitis treated with azacitidine. Azacitidine administration improved his clinical symptoms, high fever and thickening of the arterial wall, and he achieved a complete bone marrow remission. However, 1 year later he showed progression of MDS. For MDS with vasculitis, intensive therapy, the same as that given to the high-risk group, should be considered and azacitidine administration may represent an efficacious treatment.

Veno-venous extracorporeal membrane oxygenation for perioperative management of infective endocarditis after COVID-19 with acute respiratory distress syndrome: a case report.

BACKGROUND: Infective endocarditis (IE) is a rare cardiovascular complication in patients with coronavirus disease 2019 (COVID-19). IE after COVID-19 can also be complicated by acute respiratory distress syndrome (ARDS); however, the guidelines for the treatment of such cases are not clear. Here, we report a case of perioperative management of post-COVID-19 IE with ARDS using veno-venous extracorporeal membrane oxygenation (V-V ECMO). CASE PRESENTATION: The patient was a 40-year-old woman who was admitted on day 18 of COVID-19 onset and was administered oxygen therapy, remdesivir, and dexamethasone. The patient's condition improved; however, on day 24 of hospitalization, the patient developed hypoxemia and was admitted to the intensive care unit (ICU) due to respiratory failure. Blood culture revealed Corynebacterium striatum, and transesophageal echocardiography revealed vegetation on the aortic and mitral valves. Valve destruction was mild, and the cause of respiratory failure was thought to be ARDS. Despite continued antimicrobial therapy, ARDS did not improve the patient's condition, and valve destruction progressed; therefore, surgical treatment was scheduled on day 13 of ICU admission. After preoperative consultation with the team, a decision was made to initiate V-V ECMO after the patient was weaned from CPB, with concerns about further worsening of her respiratory status after surgery. The patient returned to the ICU with transition to V-V ECMO, and her circulation remained stable. The patient was weaned off V-V ECMO on postoperative day 33 and discharged from the ICU on postoperative day 47. CONCLUSIONS: ARDS may occur in patients with IE after COVID-19. Owing to concerns about further exacerbation of pulmonary damage, the timing of surgery should be comprehensively considered. Preoperatively, clinicians should discuss perioperative ECMO introduction and configuration.

A single nucleotide polymorphism in 3'-untranslated region contributes to the regulation of Toll-like receptor 4 translation.

We have previously shown that a single nucleotide polymorphism rs11536889 in the 3'-untranslated region (UTR) of TLR4 was associated with periodontitis. In this study the effects of this single nucleotide polymorphism on Toll-like receptor (TLR) 4 expression were investigated. Monocytes from subjects with the C/C genotype expressed higher levels of TLR4 on their surfaces than those from subjects with the other genotypes. Peripheral blood mononuclear cells (PBMCs) from the C/C and G/C subjects secreted higher levels of IL-8 in response to lipopolysaccharide (LPS), a TLR4 ligand, than the cells from the G/G subjects. However, there was no significant difference in TLR4 mRNA levels in PBMCs from the subjects with each genotype. After stimulation with tripalmitoylated CSK(4) (Pam(3)CSK(4)), TLR4 mRNA levels increased in PBMCs from both the C/C and G/G subjects, whereas TLR4 protein levels increased in PBMCs from the C/C but not G/G subjects. Transient transfection of a series of chimeric luciferase constructs revealed that a fragment of 3'-UTR containing rs11536889 G allele, but not C allele, suppressed luciferase activity induced by LPS or IL-6. Two microRNAs, hsa-miR-1236 and hsa-miR-642a, were predicted to bind to rs11536889 G allele. Inhibition of these microRNAs reversed the suppressed luciferase activity. These microRNA inhibitors also up-regulated endogenous TLR4 protein on THP-1 cells (the G/G genotype) after LPS stimulation. Furthermore, mutant microRNAs that bind to the C allele inhibited the luciferase activity of the construct containing the C allele. These results indicate that genetic variation of rs11536889 contributes to translational regulation of TLR4, possibly by binding to microRNAs.

Usefulness of intraoperative transesophageal echocardiography for hemodynamic management of liver transplantation in a patient with massive polycystic liver disease: a case report.

BACKGROUND: Hemodynamic management during anesthesia in liver transplantation for patients with polycystic liver disease (PLD) can be more challenging because of the bleeding and hemodynamic alterations due to the markedly enlarged liver. We hereby report a case of PLD wherein transesophageal echocardiography (TEE) was employed for optimal hemodynamic monitoring during liver transplantation. CASE PRESENTATION: A 61-year-old man was scheduled to undergo liver transplantation for massive PLD. Hemodynamic instability was associated with mechanical displacement of the giant cystic liver. TEE results revealed the collapse of the inferior vena cava due to liver displacement. TEE also detected intrathoracic hemorrhage triggered by detachment from the markedly enlarged liver. CONCLUSION: TEE is a valuable monitoring tool for sharing information with surgeons and diagnostic modality for finding the source of bleeding in liver transplantation for PLD and may contribute majorly to the quality of perioperative management.

Promotion of a venous thromboembolism prevention protocol at a perioperative management center.

Objectives: Perioperative venous thromboembolism (VTE) is a potentially fatal complication, making preoperative VTE diagnosis and secondary thromboprophylaxis important. This study was performed to investigate the impact of promotion of a preoperative VTE protocol at a perioperative management center (PMC) on detecting the preoperative VTE rate and subsequent treatment. Methods: This retrospective study involved patients aged ≥20 years who underwent elective anesthesia. The patients were divided into two groups: the pre-PMC group (January to October 2014, before the opening of the PMC) and the post-PMC group (January to December 2019, after the opening of the PMC). The rates of preoperative lower-limb compression ultrasonography (CUS), VTE detection, anticoagulation therapy, and new postoperative pulmonary embolism (PE) were compared between the two groups. Results: The pre-PMC and post-PMC groups comprised 3737 and 5388 patients, respectively. The preoperative CUS and VTE detection rates were significantly higher in the post-PMC than pre-PMC group (7.2% and 1.43% vs. 25.6% and 3.93%, respectively; P<0.001). There was no significant difference in the rate of anticoagulation therapy in patients with preoperative VTE (88.9% vs. 84.7%, P=0.43). Heparin and direct oral anticoagulants were primarily used in the pre-PMC and post-PMC groups, respectively. The efficacy and safety were comparable between the two groups. No new postoperative PE was detected in either group. Conclusions: Promotion of the preoperative VTE protocol led by the PMC increased the rates of preoperative CUS and preoperative VTE detection. This may aid in secondary thromboprophylaxis in the preoperative period and prevention of postoperative PE.

Association of circulating histone H3 and high mobility group box 1 levels with postoperative prognostic indicators in intensive care unit patients: a single-center observational study.

Objectives: Damage associated molecular patterns (DAMPs) levels are associated with sepsis severity and prognosis. Histone and high mobility group box 1 (HMGB1) levels are also potential indicators of prognosis. We investigated the relationship between serum histone H3 and HMGB1 levels and the illness severity score and prognosis in postoperative patients. Methods: Postoperative serum histone H3 and HMGB1 levels in 39 intensive care unit (ICU) patients treated at our institution were measured. The correlation between peak histone H3 and HMGB1 levels in each patient and clinical data (age, sex, surgical time, length of ICU stay, and survival after ICU discharge), which also included the patients' illness severity score, was examined. Results: Histone H3 but not HMGB1 levels were positively correlated with surgical time, the Sequential Organ Failure Assessment score, the Japanese Association for Acute Medicine acute phase disseminated intravascular coagulation diagnosis score, and the length of ICU stay. Both histone H3 and HMGB1 levels were negatively correlated with age. However, survival post-ICU discharge was not correlated with histone H3 or HMGB1 levels. Conclusions: Histone H3 levels are correlated with severity scores and the length of ICU stay. Serum histone H3 and HMGB1 levels are elevated postoperatively. These DAMPs, however, are not prognostic indicators in postoperative ICU patients.

[Clopidogrel-associated thrombotic thrombocytopenic purpura].

Thrombotic thrombocytopenic purpura (TTP) is a life-threatening disease that is a rare complication of thienopyridine treatment, especially clopidogrel. Here we report a case of clopidogrel-associated TTP. A 77-year-old male initially complained of petechiae on his legs 6 weeks after clopidogrel treatment following coronary artery stenting. He was admitted 4 weeks later with slurred speech and low-grade fever. Laboratory findings showed severe thrombocytopenia, hemolytic anemia with fragmented red cells, renal dysfunction and severe deficiency of ADAMTS13 activity with the presence of the inhibitor. Based on the clinical course and laboratory findings, he was diagnosed with TTP and underwent plasma exchange, followed by improvement of symptoms and laboratory abnormalities after 7 courses of plasma exchange. Nevertheless, the patient died of sepsis due to perforated small intestinal diverticulitis 89 days after admission. Thienopyridine-associated TTP usually occurs within 12 weeks after initiation of the therapy. Physicians should therefore be aware of this fatal complication associated with clopidogrel therapy and frequent blood tests, every 2 weeks during the first 12 weeks, is recommended for early diagnosis.

A Larger Membrane Area Increases Cytokine Removal in Polymethyl Methacrylate Hemofilters.

Blood purification is performed to control cytokines in critically ill patients. The relationship between the clearance (CL) and the membrane area during adsorption is not clear. We hypothesized that the CL increases with the hydrophobic area when hydrophobic binding contributes to cytokine adsorption. We investigated the relationship between the hemofilter membrane area and the CL of the high mobility group box 1 protein (HMGB-1) and interleukin-6 (IL-6). We performed experimental hemofiltration in vitro using polymethyl methacrylate membranes CH-1.8W (1.8 m2) and CH-1.0N (1.0 m2), as well as polysulfone membrane NV-18X (1.8 m2). After adding 100 mg of HMGB1 or 10 µg of IL-6 into the test solution, experimental hemofiltration was conducted for 360 min in a closed-loop circulation system, and the same amount of HMGB1 and IL-6 was added after 180 min. With CH-1.8W and CH-1.0N, both HMGB-1 and IL-6 showed a rapid concentration decrease of more than 70% at 180 min and 360 min after the re-addition. At 15 min, the CL of HMGB-1 was CH-1.8W: 28.4 and CH-1.0N: 19.8, and that of IL-6 was CH-1.8W: 41.1 and CH-1.0N: 25.4. CH-1.8W and CH-1.0N removed HMGB1 and IL-6 by adsorption and CH-1.8W was superior in CL, which increased with a greater membrane area.

Adsorption kinetics of high mobility group box 1 protein in a polyacrylonitrile hemofiltration membrane.

The high mobility group box 1 protein (HMGB1) is recognized as a prototypical endogenous danger cytokine in sepsis. We previously reported that a polyacrylonitrile (AN69ST) membrane rapidly adsorbed HMGB1. Herein, an in vitro hemofiltration system was designed to assess the HMGB1 adsorption capacity, adsorption sites, and adsorption mechanism of the AN69ST membrane. HMGB1 was repeatedly added seven times during hemofiltration. A rapid decrease in circulating HMGB1 was observed after every addition with no sign of saturation. Presence of HMGB1 on the filter membrane was observed on both membrane surfaces and within the bulk layer using a high concentration of HMGB1 by immunoelectron microscopy. We hypothesized that the addition of heparin to the membrane surface or filtration rate would contribute to the adsorption mechanism. We could not measure the influence of heparin and filtration. Although the membrane was too large to saturate under the µg/mL HMGB1 conditions, our results show that the AN69ST membrane has a robust absorption capacity that could be used to treat sepsis.

Comparison of myoglobin clearance in three types of blood purification modalities.

Myoglobin, which can cause acute kidney injury, has a relatively high molecular weight and is poorly cleared by diffusion. We compared and examined myoglobin clearance by changing the blood purification membrane and modality in patients with a myoglobin blood concentration ≥ 1000 ng/ml. We retrospectively analyzed three patient groups based on the following three types of continuous hemofiltration (CHF): AN69ST membrane, polymethylmethacrylate (PMMA) membrane, and high-flow hemodiafiltration (HDF) with increased dialysate flow rate using the PMMA membrane. There was no significant difference in clearance in CHF between AN69ST and PMMA membranes. However, the high-flow HDF group showed the highest myoglobin clearance (p = 0.003). In the PMMA membrane, changing the treatment modality to high-flow HDF increased clearance above the theoretical value, possibly due to internal filtration. To remove myoglobin by kidney replacement therapy from patients with hypermyoglobinemia, a modality such as high-flow HDF would be desirable.