原 嘉孝

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.

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.

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.

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.

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.