中村 智之

OBJECTIVE: To determine the impact of mobilization training time during the first postoperative week on the length of hospital stay for postoperative patients admitted to an intensive care unit. DESIGN: A retrospective cohort study. PATIENTS: Consecutive patients who underwent elective surgery and stayed in the intensive care unit of a university hospital for more than 48 h between July 2017 and August 2020 were enrolled. METHODS: The total duration of mobilization training during the first postoperative week and clinical variables, including demographic information, were collected from medical records. Multivariable regression analysis was used to investigate the impact of mobilization training time on the length of hospital stay, adjusting for potentially confounding variables. RESULTS: In total, 773 patients (504 males; median age, 70 years) were enrolled. Multivariable regression analysis showed that an increase in mobilization training time during the first postoperative week was associated with a shorter length of hospital stay (β = -0.067, 95% confidence interval: -0.120, -0.017, p = 0.010), with each 1-h increase in training time associated with a 4.02-day reduction in the length of hospital stay. CONCLUSION: Increased mobilization training during the first postoperative week significantly reduced the length of hospital stay in postoperative 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.

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.

Neutrophil extracellular trap (NET) formation, an innate immune system response, is associated with thrombogenesis and vascular endothelial injury. Circulatory disorders due to microvascular thrombogenesis are one of the principal causes of organ damage. NET formation in organs contributes to the exacerbation of sepsis, which is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. We have previously reported that recombinant human soluble thrombomodulin (rTM) reduces lipopolysaccharide (LPS)-induced NET formation in vitro. Here, we aimed to show that thrombomodulin (TM)-mediated suppression of NET formation protects against organ damage in sepsis. Mice were injected intraperitoneally (i.p.) with 10 mg/kg LPS. rTM (6 mg/kg/day) or saline was administered i.p. 1 h after LPS injection. In the LPS-induced murine septic shock model, extracellular histones, which are components of NETs, were observed in the liver and lungs. In addition, the serum cytokine (interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), macrophage chemotactic protein-1 (MCP-1), and interleukin-10 (IL-10)) levels were increased. The administration of rTM in this model prevented NET formation in the organs and suppressed the increase in the levels of all cytokines except IL-1β. Furthermore, the survival rate improved. We provide a novel role of TM in treating inflammation and NETs in organs during sepsis.

Patients who undergo renal replacement therapy often exhibit a high plasma linezolid concentration. Linezolid is metabolized via oxidation. Nafamostat mesilate has antioxidant effects and is frequently used as an anticoagulant during renal replacement therapy. We aimed to investigate the effect of nafamostat mesilate on plasma linezolid concentration. We examined whether the co-administration of linezolid and nafamostat had any effect on plasma linezolid concentration. Mice were randomly allocated to two groups (n = 18/group): linezolid (100 mg kg-1 , subcutaneous injection) + nafamostat (30 mg kg-1 , intraperitoneal injection) and linezolid + saline. At 5 hours, the linezolid concentration was significantly higher in the linezolid + nafamostat co-administration group than that in the linezolid + saline group (20.6 ± 9.8 vs 3.6 ± 1.2 μg/mL, respectively P < .001). The antioxidant effects of nafamostat may inhibit linezolid metabolism, resulting in the adverse event of high linezolid concentration if both are administered concurrently during renal replacement therapy.

We aimed to evaluate whether cardiac output assessed by transpulmonary thermodilution during blood purification is affected by the difference between the blood return temperature and core temperature. We applied different blood return temperatures using a thermostat bath during blood purification in four pigs. After the blood return temperature stabilized and blood purification process stopped, the cardiac output assessed by transpulmonary thermodilution was measured. The thermostat bath was set at 35°C, 40°C, 45°C, and 50°C, with the order changed at random; four measurements were made at each temperature. Cardiac function was evaluated by echocardiography when ice-cold saline was administered in a pig. A decrease in the blood return temperature resulted in decreased cardiac output assessed by transpulmonary thermodilution, whereas an increase resulted in increased cardiac output assessed by transpulmonary thermodilution. Echocardiography revealed that the change in the blood return temperature did not affect the left ventricular ejection fraction.