Synergistic effect of collagen and CXCL12 in the low doses on human platelet activation

CXCL12, also known as stromal cell-derived factor-1, is a chemokine classified into CXC families, which exerts its function by binding to specific receptors called CXCR4 and CXCR7. Human platelets express CXCR4 and CXCR7 on the plasma membrane. It has been reported that CXCL12 potentiates to induce platelet aggregation in cooperation with agonists including collagen. However, the precise roles and mechanisms of CXCL12 in human platelet activation are not fully elucidated. In the present study, we investigated the effect of simultaneous stimulation with low doses of collagen and CXCL12 on the activation of human platelets. The simultaneous stimulation with collagen and CXCL12 induced the secretion of platelet-derived growth factor (PDGF)-AB and the release of soluble CD40 ligand (sCD40L) from human platelets in addition to their aggregation, despite the fact that the simultaneous stimulation with thrombin receptor-activating peptide (TRAP) or adenosine diphosphate (ADP), and CXCL12 had little effects on the platelet aggregation. The agonist of Glycoprotein (GP) Ⅵ convulxin and CXCL12 also induced platelet aggregation synergistically. The monoclonal antibody against CXCR4 but not CXCR7 suppressed the platelet aggregation induced by simultaneous stimulation with collagen and CXCL12. The phosphorylation of p38 mitogen-activated protein kinase (MAPK), but not p44/p42 MAPK, was induced by the simultaneous stimulation. In addition, the simultaneous stimulation with collagen and CXCL12 induced the phosphorylation of HSP27 and the subsequent release of phosphorylated-HSP27 from human platelets. SB203580, a specific inhibitor of p38 MAPK, attenuated the platelet aggregation, the phosphorylation of p38 MAPK and HSP27, the PDGF-AB secretion, the sCD40L release and the phosphorylated-HSP27 release induced by the simultaneous stimulation with collagen and CXCL12. These results strongly suggest that collagen and CXCL12 in low doses synergistically act to induce PDGF-AB secretion, sCD40L release and phosphorylated-HSP27 release from activated human platelets via p38 MAPK activation.

JAAM Nationwide Survey on the response to the first wave of COVID-19 in Japan Part II: How the medical institutions overcame the first wave and how to prepare in future?

Aim

To investigate and clarify the surge capacity of staff/equipment/space, and patient outcome in the first wave of COVID-19 in Japan.

Methods

We analyzed questionnaire data from the end of May 2020 from 180 hospitals (total of 102,578 beds) with acute medical centers.

Results

A total of 4,938 hospitalized patients with COVID-19 were confirmed. Of 1,100 severe COVID-19 inpatients, 112 remained hospitalized and 138 died. There were 4,852 patients presumed to be severe COVID-19 patients who were confirmed later to be not infected. Twenty-seven hospitals (15% of 180 hospitals) converted their ICU to a unit for COVID-19 patients only, and 107 (59%) had to manage both severe COVID-19 patients and others in the same ICU. Restriction of ICU admission was occurred in one of the former 27 hospitals and 21 of later 107 hospitals. Shortage of N95 masks was the most serious concern regarding personal protective equipment (PPE). As for issues which raised ICU bed occupancy, difficulty performing or progressing rehabilitation for severe patients (42%), and the improved patients (28%), long lasting severely ill patients (36%) and unclear isolation criteria (34%) were mentioned. Many acute medicine physicians assisted regional governmental agencies functioning as advisors and volunteer coordinator.

Conclusion

The mortality rate of COVID-19 in this study was 4.5% of all hospitalized patients and 14% (approximately one in 7) severe patients. The hospitals with dedicated COVID-19 ICUs accepted more patients with severe COVID-19 and had lower ICU admission restrictions, which may be helpful as a strategy in the next pandemic.

Vascular endothelial injury exacerbates coronavirus disease 2019: The role of endothelial glycocalyx protection

The potential for a rapid increase in severity is among the most frightening aspects of severe acute respiratory syndrome coronavirus 2 infection. Evidence increasingly suggests that the symptoms of coronavirus disease‐2019 (COVID‐19)‐related acute respiratory distress syndrome (ARDS) differ from those of classic ARDS. Recently, the severity of COVID‐19 has been attributed to a systemic, thrombotic, and inflammatory disease that damages not only the lungs but also multiple organs, including the heart, brain, toes, and liver. This systemic form of COVID‐19 may be due to inflammation and vascular endothelial cell injury. The vascular endothelial glycocalyx comprises glycoproteins and plays an important role in systemic capillary homeostasis maintenance. The glycocalyx covers the entire vascular endothelium, and its thickness varies among organs. The endothelial glycocalyx is very thin in the pulmonary capillaries, where it is affected by gaseous exchange with the alveoli and the low intravascular pressure in the pulmonary circulation. Despite the clearly important roles of the glycocalyx in vascular endothelial injury, thrombosis, vasculitis, and inflammation, the link between this structure and vascular endothelial cell dysfunction in COVID‐19 remains unclear. In this prospective review, we summarize the importance of the glycocalyx and its potential as a therapeutic target in cases of systemic COVID‐19.

Cigarette Smoking Cessation Temporarily Enhances the Release of Phosphorylated-HSP27 from Human Platelets

Objective Cigarette smoking is a risk factor for arteriopathy, including acute coronary syndrome, stroke and peripheral vascular disease. Thus, cessation is strongly recommended in order to reduce these risks. We recently demonstrated that smoking cessation causes temporary hyper-aggregability of human platelets. We previously showed that heat shock protein 27 (HSP27) is released from human platelets stimulated by collagen, accompanied by its phosphorylation. Accumulating evidence indicates potent roles of extracellular HSP27 as a modulator of inflammation. In the present study, using the stored samples obtained in the previous study, we investigated the effect of cigarette smoking cessation on the release of phosphorylated-HSP27 from collagen-activated human platelets (n=15 patients). Methods We enrolled patients who visited smoking cessation outpatient services between January 2012 and November 2014. Platelet-rich plasma, chronologically obtained before and after the cessation, was stimulated by collagen using a PA-200 aggregometer in the previous study. The levels of phosphorylated-HSP27 released from platelets were determined by an enzyme-linked immunosorbent assay. The phosphorylation of HSP27 in platelets was evaluated by a Western blot analysis. Results Cessation of cigarette smoking significantly upregulated the levels of collagen-stimulated release of phosphorylated-HSP27 at four and eight weeks after quitting smoking compared to before cessation. However, there was no significant difference between the levels before cessation and those at 12 weeks after cessation. The levels of phosphorylated-HSP27 stimulated by collagen in the platelets at four weeks after smoking cessation were remarkably enhanced compared to before cessation. Conclusion Cigarette smoking cessation temporarily enhances the collagen-stimulated release of phosphorylated-HSP27 from human platelets in the short term.

Recombinant thrombomodulin protects against LPS-induced acute respiratory distress syndrome via preservation of pulmonary endothelial glycocalyx

Background and Purpose

Disruption of the endothelial glycocalyx is causally related to microvascular endothelial dysfunction, a characteristic of sepsis‐induced acute respiratory distress syndrome (ARDS). Recombinant human thrombomodulin (rhTM) attenuates vascular endothelial injuries, but the underlying mechanism remains elusive. Here, we investigated the structural basis and molecular mechanisms of rhTM effects on vascular endothelial injury in a model of sepsis.

Experimental Approach

LPS (20 mg·kg⁻¹) was intraperitoneally injected into 10‐week‐old male C57BL6 mice, and saline or rhTM was intraperitoneally injected 3 and 24 h after LPS injection. Using serum and/or lung tissue, histological, ultrastructural, and microarray analyses were performed.

Key Results

Survival rate of rhTM‐treated mice was significantly higher than that of control mice 48 h after LPS injection. Serum concentrations of IL‐6 and high‐mobility group box 1 were lower in the rhTM‐treated group than in the control. Injury to the endothelial glycocalyx in pulmonary capillaries was attenuated by rhTM treatment. Gene set enrichment analysis revealed up‐regulation of gene sets corresponding to cell proliferation/differentiation and anti‐inflammation, such as the TGF‐β pathway, and negative regulation of IL‐6, upon rhTM treatment. Gene expression of heparan sulfate 6‐O‐sulfotransferase 1 and endothelial cell‐specific molecule 1 (components of the endothelial glycocalyx) was significantly preserved by rhTM treatment, and their protein expression levels were maintained in endothelial cells.

Conclusion and Implications

Our findings show that rhTM treatment affected inflammation, cell proliferation/differentiation, and glycocalyx synthesis in serum and lung tissue, subsequently attenuating ARDS caused by endothelial injury.

Anti-allergic effect of the Src family kinase inhibitor saracatinib

The aim of this study was to evaluate the anti-anaphylactic and anti-allergic potentials of saracatinib, a Src family kinase inhibitor that was already shown to be safe in clinical trials when it was used as an anti-cancer drug. Using in vitro mast cell models, we found that saracatinib inhibited the degranulation response and cytokine production in RBL2H3 cells that were stimulated with IgE and antigen without affecting cell viability. Phosphorylation of Lyn, Akt, a PI3K substrate, and MAPKs including ERK, JNK, and p38, as well as the intracellular Ca²⁺ increase induced by this stimulation were also suppressed by saracatinib. This drug also inhibited symptoms in our established anaphylaxis mouse model, anaphylaxis-dependent spotted distribution of immune complex in skin (ASDIS). The intravenous injection of the mixture of IgE and antigen induced acute spotted distribution of immune complex in skin in hairless HR-1 mice, and its inhibition by intradermal injection of saracatinib was observed. Moreover, toluidine blue-stained skin sections indicated that the degranulation ratio of dermal mast cells was reduced in saracatinib-treated skin compared with vehicle-treated skin. Because only a few signaling inhibitors are used as anti-anaphylaxis and anti-allergic drugs, these results indicated the valuable suggestion that saracatinib and the Src family kinase inhibitors are good candidates for anti-anaphylaxis and anti-allergic drugs.

The Prognostic Significance of Pretransplant Plasma Fibrinogen Levels in Autologous Hematopoietic Stem Cell Transplantation

Elevated plasma fibrinogen is associated with tumor progression and poor outcomes in several cancers. However, no studies have demonstrated the prognostic value of hyperfibrinogenemia in the setting of autologous hematopoietic stem cell transplantation (ASCT). We retrospectively reviewed 104 patients who were diagnosed with malignant lymphoma (ML) or multiple myeloma (MM) and underwent ASCT in our institution between 2007 and 2018. The patients included 63 men and 41 women with a median age of 58 years (range, 24-70 years). Forty-seven patients were diagnosed with ML, and 57 patients were diagnosed with MM. The median follow-up period was 59 months. The median pretransplant plasma fibrinogen levels were 336 mg/dL in ML patients and 320 mg/dL in MM patients. The Kaplan-Meier method revealed that patients with pretransplant hyperfibrinogenemia had a significantly shorter 5-year overall survival (OS) than those without hyperfibrinogenemia (5-year OS: 34.3% vs 81.0%, P < .001). Among 27 patients with diffuse large B cell lymphoma, patients with pretransplant hyperfibrinogenemia (n = 12) had a significantly shorter OS than those without hyperfibrinogenemia (n = 15) (5-year OS: 40.0% vs 80.2%, P = .006). Among 57 MM patients, there was no significant difference in the 5-year OS between the high-fibrinogen group and the low-fibrinogen group (5-year OS: 77.1% vs 50.4%, P = .17). Our study suggested that pretransplant hyperfibrinogenemia was associated with a poor survival in patients with lymphoma who underwent ASCT. Because our results are based on a small-sized analysis, further large-scale prospective studies are warranted to verify this conclusion.

The prognostic value of the controlling nutritional status score in patients with multiple myeloma

The Controlling Nutritional Status (CONUT) score predicts the prognosis in several tumors. However, its prognostic significance in multiple myeloma (MM) remains unclear. The present study investigated the correlation between the CONUT score and the survival outcomes of MM patients. A total of 178 patients newly diagnosed with MM were retrospectively enrolled. Patients with a high CONUT score (≥5) had a significantly shorter median overall survival (OS) than those with a low CONUT score (≤4) (33 vs. 57 months, p < .001). In a multivariate analysis among patients with International Staging System (ISS) score of ≤2, a high CONUT score was an independent prognostic covariate for the OS after adjusting for other significant factors (hazard ratio 2.364; 95% confidence interval 1.324-4.220, p = .004). Our results suggest that the CONUT score is a predictor of a poor outcome in patients with MM, particularly in low-ISS-score cases.

Diffuse midline glioma in the spinal cord with rapid respiratory deterioration

Background

Neurogenic acute respiratory failure is usually caused by either infection or vascular insufficiency. We report the case of a patient who developed acute respiratory failure secondary to a spinal tumor.

Case Presentation

A 32‐year‐old man, presenting with numbness and muscle weakness in his legs for 2 weeks, was transferred to our hospital with worsening quadriplegia and development of respiratory symptoms. We carried out emergent spinal decompression and initiated steroid pulse therapy, with no resolution of symptoms; a tumor incision biopsy after contrast cervical magnetic resonance imaging revealed an intraspinal tumor with a pathological diagnosis of World Health Organization grade IV glioma. The patient developed bradycardia, severe sepsis, status epilepticus, and cardiopulmonary arrest due to hypoxemia and was treated with chemoradiotherapy under mechanical ventilation. He was later transferred to another hospital for subacute care.

Conclusion

Acute respiratory failure caused by spinal tumors is uncommon. However, acute care practitioners should be mindful of neoplastic lesions as a potential cause.

Multiple trauma including pelvic fracture with multiple arterial embolization: an autopsy case report

Background

Pelvic fracture with high energy trauma has a high mortality rate, especially in men. In addition, severe multiple trauma, major hemorrhage, and administration of red blood cells predict mortality in elderly patients with pelvic fracture. We herein report a rare case in which multiple arterial embolization occurred after pelvic fracture.

Case presentation

An 83-year-old male cyclist was transported to our hospital after being struck by a car. On arrival, he was diagnosed with multiple trauma, including rib fractures with hemothorax, lumbar fractures of the transverse process, and injuries in the right acetabulum, left adrenal gland, and liver. He underwent massive transfusion and transcatheter arterial embolization due to extravasation from the right superior gluteal artery and left adrenal gland. On the second day, owing to right lower leg ischemia, serum creatinine kinase and myoglobin levels were markedly elevated from the reference value; hence, a right above-knee amputation was performed 12 h after the accident. However, both protein levels remained high after amputation, resulting in acute renal injury, which was treated via hemodiafiltration on hospital day 3. In addition, sustained low efficiency hemodialysis and plasma exchange were performed on hospital day 4. Despite these treatments, the patient’s hemodynamics did not improve, and he died on hospital day 8. The autopsy revealed necropsy of the iliopsoas muscles and the digestive tract.

Conclusions

The causes of the patient’s death were considered to be persistent rhabdomyolysis and severe hypotension due to iliopsoas necrosis and peritonitis due to digestive tract necrosis. Multiple arterial embolization caused by consumption coagulopathy associated with multiple trauma may account for severe outcomes in this case.

Weather Fluctuations May Have an Impact on Stroke Occurrence in a Society: A Population-Based Cohort Study

Background

Stroke has been found to have a seasonally varying incidence; blood pressure, one of its risk factors, is influenced by humidity and temperature. The relationship between the incidence of stroke and meteorological parameters remains controversial.

Objective

We investigated whether meteorological conditions are significant risk factors for stroke, focusing on the fluctuation of weather elements that triggers the onset of stroke.

Methods

We collected ambulance transportation data recorded by emergency personnel from Gifu Prefecture. We included cases where the cause of the transportation was stroke and excluded cases of trauma. We combined these data with meteorological data as well as data on average temperature, average air pressure, and humidity provided publicly by the Japan Meteorological Agency. Our target period was from January 2012 to December 2016.

Results

In the 5-year target period, there were 5,501 occurrences of ambulance transportation due to stroke. A seasonal tendency was confirmed, since ambulance transportation for stroke occurred more frequently at low temperatures (p < 0.001). Temperature (odds ratio: 0.91; p < 0.001) and humidity change (odds ratio: 1.50; p = 0.016) were identified as risk factors for ambulance transportation due to stroke. An increase in temperature incurs a lower risk than a decrease (odds ratio: 0.58; p = 0.09), although there is no statistically significant difference.

Conclusions

Meteorological effects on the frequency of ambulance transportation due to stroke were studied. A lower temperature and radical humidity change were identified as risk factors for ambulance transportation due to stroke, and a decrease in temperature was also associated. We speculate on the possibilities of using meteorological data to optimize the assignment of limited medical resources in medical economics.

In situ nuclear DNA methylation in dilated cardiomyopathy: an endomyocardial biopsy study

AIMS

Although distinct DNA methylation patterns have been reported, its localization and roles remain to be defined in heart failure. We investigated the cellular and subcellular localization of DNA methylation and its pathophysiological significance in human failing hearts.

METHODS AND RESULTS

Using left ventricular (LV) endomyocardial biopsy specimens from 75 patients with dilated cardiomyopathy (DCM; age: 58 ± 14 years old, %female: 32%) and 20 patients without heart failure (controls; age: 56 ± 17 years old, %female: 45%), we performed immunohistochemistry and immunoelectron microscopy for methylated DNA, 5-methylcytosine (5-mC). We next investigated possible relations of the incidence of 5-mC-positive (%5-mC⁺ ) cardiomyocytes with clinicopathological parameters. Immunopositivity for 5-mC was detected in the cardiomyocytes and other cell types. The %5-mC⁺ cardiomyocytes was significantly greater in DCM hearts than in controls (57 ± 13% in DCM vs. 25 ± 12% in controls, P < 0.0001). The localization of 5-mC immunopositivity in cardiomyocyte nuclei coincided well with that of heterochromatin, as confirmed by immunoelectron microscopy. Substantial DNA methylation was also observed in interstitial non-cardiomyocytes, but the incidences did not differ between control and DCM hearts (39 ± 7.9% in DCM vs. 41 ± 10% in controls, P = 0.4099). In DCM patients, the %5-mC⁺ cardiomyocytes showed a significant inverse correlation with LV functional parameters such as heart rate (r = 0.2391, P = 0.0388), end-diastolic pressure (r = 0.2397, P = 0.0397), and ejection fraction (r = -0.2917, P = 0.0111) and a positive correlation with LV dilatation (volume index at diastole; r = 0.2442, P = 0.0347; and volume index at systole; r = 0.3136, P = 0.0062) and LV hypertrophy (mass index; r = 0.2287, P = 0.0484)-that is, LV remodelling parameters. No significant correlations between DNA methylation and the histological parameters of the biopsies, including cardiomyocyte hypertrophy, fibrosis, and inflammatory cell infiltration, were noted.

CONCLUSIONS

The present study revealed increased nuclear DNA methylation in cardiomyocytes, but not other cell types, from DCM hearts, with predominant localization in the heterochromatin. Its significant relations with LV functional and remodelling parameters imply a pathophysiological significance of DNA methylation in heart failure.

Olive polyphenol reduces the collagen-elicited release of phosphorylated HSP27 from human platelets

Hydroxytyrosol (HT) and oleuropein (OLE) are natural polyphenols found in extra virgin olive oil. Accumulating evidence indicates that ingestion of olive oil contributes to reduce the risk of cardiovascular diseases and stroke. It has been reported that HT and OLE inhibit human platelet aggregation. We have shown that collagen induces the phosphorylation of heat shock protein 27 (HSP27) in human platelets, resulting in the release of HSP27, an extracellular pro-inflammatory agent. In this study, we investigated the effects of HT and OLE on the collagen-stimulated human platelet activation. The PDGF-AB secretion and the soluble CD40 ligand (sCD40L) release by collagen were reduced by HT or OLE. HT and OLE significantly suppressed the phosphorylation of HSP27 and the release of phosphorylated-HSP27. These findings suggest that olive polyphenol reduces the collagen-stimulated phosphorylation of HSP27 in human platelets and the release. Our results may provide a novel anti- inflammatory effect of olive polyphenol.

Herpes zoster and meningitis in an immunocompetent child: a case report

Background

Development of neurological complications of varicella zoster virus reactivation is relatively uncommon, particularly in an immunocompetent child.

Case presentation

An 11-year-old Asian girl presented with headache and skin rash on her left chest. She was diagnosed with meningitis, and herpes zoster was confirmed by polymerase chain reaction using cerebrospinal fluid. Acyclovir was administered intravenously. Given the favorable evolution of the clinical course, she was discharged from the hospital on day 8 of her illness. She had no apparent sequelae or comorbidities at the time of the 6-week follow-up.

Conclusions

Neurological complications such as meningitis due to varicella zoster virus reactivation are uncommon, especially in an immunocompetent child; no specific immune deficiency was identified in our patient. We conclude that, although rare, varicella zoster virus should be recognized as a potential cause of viral meningitis in immunocompetent children.

Neutrophil Elastase Damages the Pulmonary Endothelial Glycocalyx in Lipopolysaccharide-Induced Experimental Endotoxemia

Neutrophil elastase (NE) is necessary for effective sterilization of phagocytosed bacterial and fungal pathogens; however, NE increases alveolocapillary permeability and induces proinflammatory cytokine production in sepsis-induced acute respiratory distress syndrome. Under septic conditions, the pulmonary endothelial glycocalyx covering on the healthy endothelium surface is injured, but the contribution of NE to this injury remains unknown. Our aim was to examine whether NE-induced pulmonary endothelial injury is associated with endotoxemia. Lipopolysaccharide (LPS; 20 mg/kg) was injected intraperitoneally into 9- to 12-week-old granulocyte colony-stimulating factor knockout (G-CSFKO) mice, which harbor few neutrophils, and littermate control mice; in a second assay, mice were injected with the NE-inhibitor sivelestat (0.2 mg/kg) at 3, 6, 9, and 12 hours after LPS administration. Subsequently, vascular endothelial injury was evaluated through ultrastructural analysis. At 48 hours after LPS injection, survival rate was more than threefold higher among G-CSFKO than control mice, and degradation of both thrombomodulin and syndecan-1 was markedly attenuated in G-CSFKO compared with control mice. Ultrastructural analysis revealed attenuated vascular endothelial injury and clear preservation of the endothelial glycocalyx in G-CSFKO mice. Moreover, after LPS exposure, survival rate was approximately ninefold higher among sivelestat-injected mice than control mice, and sivelestat treatment potently preserved vascular endothelial structures and the endothelial glycocalyx. In conclusion, NE is associated with pulmonary endothelial injury under LPS-induced endotoxemic conditions.

Incidental findings on whole-body computed tomography in trauma patients: the current state of incidental findings and the effect of implementation of a feedback system

Aim

Whole‐body computed tomography (CT) for trauma occasionally reveals significant incidental findings not related to trauma, which require an adequate response. In this study, we examined the current state of incidental findings in trauma patients on whole‐body CT and the effects of the feedback system.

Methods

The subject sample included trauma patients who underwent whole‐body CT while being examined for trauma during the 2‐year period, with the interpretation of the CT reported by a radiologist. The frequency and recognition of incidental findings and the involved body region were investigated. The state of incidental findings before and after implementation of a radiography report feedback system was also examined.

Results

During the study period, whole‐body CT revealed incidental findings in 79 of 199 trauma patients (40.1%). The mean age of the 79 patients with incidental findings was 62.8 ± 19.5 years, and the mean injury severity score was 16.6 ± 10.0. No difference was observed in the severity of trauma, age, or length of hospital stay. The incidental findings were related to the liver/gallbladder in 22 patients, kidneys in 17, lungs in 14, and the intracranial area in 13. The recognition rate of incidental findings after the implementation of the feedback system increased from 23.3% to 32.6%.

Conclusions

Considering that not all incidental findings are accurately recognized, a proper feedback system is required. A feedback system is beneficial and a need to ensure improvement in the recognition of incidental findings.

Risk factors for decreased teicoplanin trough concentrations during initial dosing in critically ill patients

Aim of the study: Here, we investigated the risk factors for decreased teicoplanin plasma trough concentrations relative to the initial dosing in critically ill patients. Patients and methods: Data obtained from 80 eligible critically ill patients who received intravenous teicoplanin were retrospectively analyzed. Risk factors for decreases in teicoplanin trough concentrations 72 h after administration of teicoplanin of more than 30% relative to predicted concentrations based on initial dosing setting were identified by logistic regression analysis. Results: Although prediction trough concentration and total dose of two days no significant differences were seen between the variation group and the non-variation group, actual trough concentration was significantly different between two groups (19.9±5.6 μg/ml vs 10.3±2.2 μg/ml, p < 0.001). In multivariate analysis, serum albumin ≤ 2.2 mg/dl (odds ratio [OR] = 3.003, 95% CI 1.072-8.408; p = 0.036) and SOFA score ≥ 9 (OR = 3.498, 95% CI 1.171-10.450; p = 0.025) were significant risk factors for decreased teicoplanin plasma trough concentrations. Conclusion: In critically ill patients, high SOFA score and low serum albumin were risk factors for decreased teicoplanin plasma trough concentration during initial dosing.

Effect of high-flow high-volume-intermittent hemodiafiltration on metformin-associated lactic acidosis with circulatory failure: a case report

Background

Metformin-associated lactic acidosis is a well-known life-threatening complication of metformin. We here report the case of a patient who developed metformin-associated lactic acidosis without organ manifestations, due to the simultaneous ingestion of an overdose of metformin and alcohol, and who recovered with high-flow high-volume intermittent hemodiafiltration.

Case presentation

A 44-year-old Asian woman with type 2 diabetes attempted suicide by ingesting 10 tablets of metformin 500 mg and drinking approximately 600 mL of Japanese sake containing 15% alcohol. She was transferred to our emergency department because of disturbed consciousness. Continuous intravenous administration of noradrenalin (0.13 μg/kg per minute) was given because she was in shock. Laboratory findings included a lactate level of 119 mg/dL (13.2 mmol/L), bicarbonate of 14.5 mmol/L, and serum metformin concentration of 1138 ng/mL. She was diagnosed as having metformin-associated lactic acidosis worsened by alcohol. After 4560 mL of bicarbonate ringer (Na⁺ 135 mEq/L, K⁺ 4 mEq/L, Cl⁻ 113 mEq/L, HCO₃⁻ 25 mEq/L) was administered, high-flow high-volume intermittent hemodiafiltration.

(dialysate flow rate: 500 mL/min, substitution flow rate: 3.6 L/h) was carried out for 6 h to treat metabolic acidosis and remove lactic acid and metformin. Consequently, serum metformin concentration decreased to 136 ng/mL and noradrenalin administration became unnecessary to maintain normal vital signs. On hospital day 12, she was moved to the psychiatry ward.

Conclusions

HFHV-iHDF may be able to remove metformin and lactic acid efficiently and may improve the condition of hemodynamically unstable patients with metformin-associated lactic acidosis.