方山 真朱

BACKGROUND: The dynamic regional accuracy of electrical impedance tomography has not yet been validated. We aimed to compare the regional accuracy of electrical impedance tomography with that of four-dimensional computed tomography during dynamic ventilation. METHODS: This single-center, prospective, observational study conducted in a general intensive care unit included adult patients receiving mechanical ventilation from July 2021 to February 2024. The patients were mechanically ventilated passively and underwent electrical impedance tomography and four-dimensional computed tomography on the same day. RESULTS: Overall, 45 patients were analyzed. The correlation coefficients in regional dynamic ventilation between four-dimensional computed tomography and electrical impedance tomography in each region were 0.963, 0.963, 0.835 (ventral, central, and dorsal, respectively) in the right lung and 0.947, 0.927, 0.823 (ventral, central, and dorsal, respectively) in the left lung. The correlation coefficient was low when the regional ventilation distribution detected by the electrical impedance tomography was < 2%. After excluding nine patients with a regional ventilation distribution of < 2%, the ventral, central, and dorsal correlation coefficients were 0.963, 0.963, and 0.946 in the right lung and 0.942, 0.924, and 0.951, respectively, in the left lung. CONCLUSIONS: Regional ventilation using electrical impedance tomography during dynamic ventilation was highly accurate and consistent with the time phase compared to four-dimensional computed tomography. Given the high correlation between these modalities, they can contribute significantly to further studies on regional ventilation dynamics. Trial registration number ClinicalTrials.gov (No. UMIN00044386).

Normally aerated lung tissue on computed tomography (CT) is correlated with static respiratory system compliance (Crs) at zero end-expiratory pressure. In clinical practice, however, patients with acute respiratory failure are often managed using elevated PEEP levels. No study has validated the relationship between lung volume and tissue and Crs at the applied positive end-expiratory pressure (PEEP). Therefore, this study aimed to demonstrate the relationship between lung volume and tissue on CT and Crs during the application of PEEP for the clinical management of patients with acute respiratory distress syndrome due to COVID-19. Additionally, as a secondary outcome, the study aimed to evaluate the relationship between CT characteristics and Crs, considering recruitability using the recruitment-to-inflation ratio (R/I ratio). We analyzed the CT and respiratory mechanics data of 30 patients with COVID-19 who were mechanically ventilated. The CT images were acquired during mechanical ventilation at PEEP level of 15 cmH2O and were quantitatively analyzed using Synapse Vincent system version 6.4 (Fujifilm Corporation, Tokyo, Japan). Recruitability was stratified into two groups, high and low recruitability, based on the median R/I ratio of our study population. Thirty patients were included in the analysis with the median R/I ratio of 0.71. A significant correlation was observed between Crs at the applied PEEP (median 15 [interquartile range (IQR) 12.2, 15.8]) and the normally aerated lung volume (r = 0.70 [95% CI 0.46-0.85], P < 0.001) and tissue (r = 0.70 [95% CI 0.46-0.85], P < 0.001). Multivariable linear regression revealed that recruitability (Coefficient = - 390.9 [95% CI - 725.0 to - 56.8], P = 0.024) and Crs (Coefficient = 48.9 [95% CI 32.6-65.2], P < 0.001) were significantly associated with normally aerated lung volume (R-squared: 0.58). In this study, Crs at the applied PEEP was significantly correlated with normally aerated lung volume and tissue on CT. Moreover, recruitability indicated by the R/I ratio and Crs were significantly associated with the normally aerated lung volume. This research underscores the significance of Crs at the applied PEEP as a bedside-measurable parameter and sheds new light on the link between recruitability and normally aerated lung.

Whether empirical therapy with carbapenems positively affects the outcomes of critically ill patients with bacterial infections remains unclear. This study aimed to investigate whether the use of carbapenems as the initial antimicrobial administration reduces mortality and whether the duration of carbapenem use affects the detection of multidrug-resistant (MDR) pathogens. This was a post hoc analysis of data acquired from Japanese participating sites from a multicenter, prospective observational study [Determinants of Antimicrobial Use and De-escalation in Critical Care (DIANA study)]. A total of 268 adult patients with clinically suspected or confirmed bacterial infections from 31 Japanese intensive care units (ICUs) were analyzed. The patients were divided into two groups: patients who were administered carbapenems as initial antimicrobials (initial carbapenem group, n = 99) and those who were not administered carbapenems (initial non-carbapenem group, n = 169). The primary outcomes were mortality at day 28 and detection of MDR pathogens. Multivariate logistic regression analysis revealed that mortality at day 28 did not differ between the two groups [18 (18%) vs 27 (16%), respectively; odds ratio: 1.25 (95% confidence interval (CI): 0.59-2.65), P = 0.564]. The subdistribution hazard ratio for detecting MDR pathogens on day 28 per additional day of carbapenem use is 1.08 (95% CI: 1.05-1.13, P < 0.001 using the Fine-Gray model with death regarded as a competing event). In conclusion, in-hospital mortality was similar between the groups, and a longer duration of carbapenem use as the initial antimicrobial therapy resulted in a higher risk of detection of new MDR pathogens.IMPORTANCEWe found no statistical difference in mortality with the empirical use of carbapenems as initial antimicrobial therapy among critically ill patients with bacterial infections. Our study revealed a lower proportion of inappropriate initial antimicrobial administrations than those reported in previous studies. This result suggests the importance of appropriate risk assessment for the involvement of multidrug-resistant (MDR) pathogens and the selection of suitable antibiotics based on risk. To the best of our knowledge, this study is the first to demonstrate that a longer duration of carbapenem use as initial therapy is associated with a higher risk of subsequent detection of MDR pathogens. This finding underscores the importance of efforts to minimize the duration of carbapenem use as initial antimicrobial therapy when it is necessary.

BACKGROUND: Sepsis-3 emphasizes the recognition of sepsis-induced cellular metabolic abnormalities, and utilizes serum lactate level as a biomarker of cellular metabolic abnormalities. Magnesium plays an important role as a cofactor in glucose metabolism, although it is not well known that magnesium deficiency causes elevated serum lactate levels. Additionally, it remains unclear how magnesium status affects the role of serum lactate levels as a marker of metabolic abnormalities in sepsis. Thus, this study aimed to investigate the association between serum magnesium and lactate levels in patients with sepsis and explore this relationship from the perspectives of time course and circulatory abnormalities. METHODS: This retrospective observational study of adult patients with sepsis was performed at the 16-bed intensive care unit of Jichi Medical University Hospital between June 2011 and December 2017. The relationship between serum magnesium and lactate levels for 5 days from intensive care unit admission was investigated along the time course. Multivariate logistic regression analysis was performed to evaluate the association between serum magnesium and lactate levels during intensive care unit admission. RESULTS: Among 759 patients included, 105 had hypomagnesemia (magnesium level < 1.6 mg/dL), 558 had normal serum magnesium levels (1.6-2.4 mg/dL), and 96 had hypermagnesemia (magnesium level > 2.4 mg/dL) at intensive care unit admission. From intensive care unit admission to day 5, the hypomagnesemia group had higher serum lactate levels and a higher frequency of lactic acidosis than the normal magnesium level and hypermagnesemia groups (70% vs. 51.6% vs. 50%; P < 0.001). Hypomagnesemia at intensive care unit admission was independently associated with lactic acidosis, i.e., lactic acid level > 2 mmol/L (odds ratio, 2.76; 95% confidence interval, 1.60-4.76; P < 0.001). CONCLUSIONS: Hypomagnesemia was associated with serum lactate levels in the early and post-resuscitation phases of sepsis. Further studies are needed to elucidate whether the magnesium status is associated with sepsis-induced cellular and metabolic abnormalities.

A 45-year-old woman was hospitalized with severe coronavirus disease 2019 pneumonia. Following cytokine storm-induced multiorgan failure and lethal arrhythmia, the patient developed a sustained coma with flaccid quadriplegia. A cerebrospinal fluid examination excluded infectious and immunogenic encephalopathies, and diffusion-weighted magnetic resonance imaging demonstrated high-intensity areas in the white matter with a cortex-sparing distribution, suggesting delayed post-hypoxic leukoencephalopathy. As a result of intensive cardiopulmonary support for a month, the neurological function gradually recovered. Based on the reversible clinical course noted in this patient, accurate diagnosis and persistent medical approaches are important for the management of coronavirus disease 2019-related delayed post-hypoxic leukoencephalopathy.

BACKGROUND: Most ventilators measure airway occlusion pressure (occlusion P0.1) by occluding the breathing circuit; however, some ventilators can predict P0.1 for each breath without occlusion. Nevertheless, few studies have verified the accuracy of continuous P0.1 measurement. The aim of this study was to evaluate the accuracy of continuous P0.1 measurement compared with that of occlusion methods for various ventilators using a lung simulator. METHODS: A total of 42 breathing patterns were validated using a lung simulator in combination with 7 different inspiratory muscular pressures and 3 different rise rates to simulate normal and obstructed lungs. PB980 and Dräger V500 ventilators were used to obtain occlusion P0.1 measurements. The occlusion maneuver was performed on the ventilator, and a corresponding reference P0.1 was recorded from the ASL5000 breathing simulator simultaneously. Hamilton-C6, Hamilton-G5, and Servo-U ventilators were used to obtain sustained P0.1 measurements (continuous P0.1). The reference P0.1 measured with the simulator was analyzed by using a Bland-Altman plot. RESULTS: The 2 lung mechanical models capable of measuring occlusion P0.1 yielded values equivalent to reference P0.1 (bias and precision values were 0.51 and 1.06, respectively, for the Dräger V500, and were 0.54 and 0.91, respectively, for the PB980). Continuous P0.1 for the Hamilton-C6 was underestimated in both the normal and obstructive models (bias and precision values were -2.13 and 1.91, respectively), whereas continuous P0.1 for the Servo-U was underestimated only in the obstructive model (bias and precision values were -0.86 and 1.76, respectively). Continuous P0.1 for the Hamilton-G5 was mostly similar to but less accurate than occlusion P0.1 (bias and precision values were 1.62 and 2.06, respectively). CONCLUSIONS: The accuracy of continuous P0.1 measurements varies based on the characteristics of the ventilator and should be interpreted by considering the characteristics of each system. Moreover, measurements obtained with an occluded circuit could be desirable for determining the true P0.1.

PURPOSE OF REVIEW: The last 25 years have seen considerable development in modes of closed-loop ventilation and there are now several of them commercially available. They not only offer potential benefits for the individual patient, but may also improve the organization within the intensive care unit (ICU). Clinicians are showing both greater interest and willingness to address the issues of a caregiver shortage and overload of bedside work in the ICU. This article reviews the clinical benefits of using closed-loop ventilation modes, with a focus on control of oxygenation, lung protection, and weaning. RECENT FINDINGS: Closed-loop ventilation modes are able to maintain important physiological variables, such as oxygen saturation measured by pulse oximetry, tidal volume (VT), driving pressure (ΔP), and mechanical power (MP), within target ranges aimed at ensuring continuous lung protection. In addition, these modes adapt the ventilator support to the patient's needs, promoting diaphragm activity and preventing over-assistance. Some studies have shown the potential of these modes to reduce the duration of both weaning and mechanical ventilation. SUMMARY: Recent studies have primarily demonstrated the safety, efficacy, and feasibility of using closed-loop ventilation modes in the ICU and postsurgery patients. Large, multicenter randomized controlled trials are needed to assess their impact on important short- and long-term clinical outcomes, the organization of the ICU, and cost-effectiveness.

BACKGROUND: Hypomagnesemia reportedly has significant associations with poor clinical outcomes such as increased mortality and septic shock in patients with sepsis. Although the mechanism underlying these outcomes mostly remains unclear, some experimental data suggest that magnesium deficiency could potentiate coagulation activation in sepsis. However, in sepsis, the association between serum magnesium levels and coagulopathy, including disseminated intravascular coagulation (DIC), remains unknown. Thus, we aimed to investigate the relationship between serum magnesium levels and coagulation status and the association between hypomagnesemia and DIC in patients with sepsis. METHODS: This retrospective observational study was conducted at the intensive care unit (ICU) of a university hospital from June 2011 to December 2017. Patients older than 19 years who met the Sepsis-3 definition were included. We categorized patients into three groups according to their serum magnesium levels: hypomagnesemia (< 1.6 mg/dL), normal serum magnesium level (1.6-2.4 mg/dL), and hypermagnesemia (> 2.4 mg/dL). We investigated the association between serum magnesium levels and overt DIC at the time of ICU admission according to the criteria of the International Society on Thrombosis and Haemostasis. RESULTS: Among 753 patients included in this study, 181 had DIC, 105 had hypomagnesemia, 552 had normal serum magnesium levels, and 96 had hypermagnesemia. Patients with hypomagnesemia had a more activated coagulation status indicated by lower platelet counts, lower fibrinogen levels, higher prothrombin time-international normalized ratios, higher thrombin-antithrombin complex, and more frequent DIC than those with normal serum magnesium levels and hypermagnesemia (DIC: 41.9% vs. 20.6% vs. 24.0%, P < 0.001). The coagulation status in patients with hypomagnesemia was more augmented toward suppressed fibrinolysis than that in patients with normal serum magnesium levels and hypermagnesemia. Multivariate logistic regression revealed that hypomagnesemia was independently associated with DIC (odds ratio, 1.69; 95% confidence interval, 1.00-2.84; P = 0.048) after adjusting for several confounding variables. CONCLUSIONS: Patients with hypomagnesemia had a significantly activated coagulation status and suppressed fibrinolysis. Hypomagnesemia was independently associated with DIC in patients with sepsis. Therefore, the treatment of hypomagnesemia may be a potential therapeutic strategy for the treatment of coagulopathy in sepsis.

BACKGROUND: Since the response to lung recruitment varies greatly among patients receiving mechanical ventilation, lung recruitability should be assessed before recruitment maneuvers. The pressure-volume curve (PV curve) and recruitment-to-inflation ratio (R/I ratio) can be used bedside for evaluating lung recruitability and individualing positive end-expiratory pressure (PEEP). Lung tissue recruitment on computed tomography has been correlated with normalized maximal distance (NMD) of the quasi-static PV curve. NMD is the maximal distance between the inspiratory and expiratory limb of the PV curve normalized to the maximal volume. However, the relationship between the different parameters of hysteresis of the quasi-static PV curve and R/I ratio for recruitability is unknown. METHODS: We analyzed the data of 33 patients with severe coronavirus disease 2019 (COVID-19) who received invasive mechanical ventilation. Respiratory waveform data were collected from the ventilator using proprietary acquisition software. We examined the relationship of the R/I ratio, quasi-static PV curve items such as NMD, and respiratory system compliance (Crs). RESULTS: The median R/I ratio was 0.90 [interquartile range (IQR), 0.70-1.15] and median NMD was 41.0 [IQR, 37.1-44.1]. The NMD correlated significantly with the R/I ratio (rho = 0.74, P < 0.001). Sub-analysis showed that the NMD and R/I ratio did not correlate with Crs at lower PEEP (- 0.057, P = 0.75; and rho = 0.15, P = 0.41, respectively). On the contrary, the ratio of Crs at higher PEEP to Crs at lower PEEP (Crs ratio (higher/lower)) moderately correlated with NMD and R/I ratio (rho = 0.64, P < 0.001; and rho = 0.67, P < 0.001, respectively). CONCLUSIONS: NMD of the quasi-static PV curve and R/I ratio for recruitability assessment are highly correlated. In addition, NMD and R/I ratio correlated with the Crs ratio (higher/lower). Therefore, NMD and R/I ratio could be potential indicators of recruitability that can be performed at the bedside.

BACKGROUND: Large multicenter studies reporting on the association between the duration of broad-spectrum antimicrobial administration and the detection of multidrug-resistant (MDR) bacteria in the intensive care unit (ICU) are scarce. We evaluated the impact of broad-spectrum antimicrobial therapy for more than 72 h on the detection of MDR bacteria using the data from Japanese patients enrolled in the DIANA study. METHODS: We analyzed the data of ICU patients in the DIANA study (a multicenter international observational cohort study from Japan). Patients who received empirical antimicrobials were divided into a broad-spectrum antimicrobial group and a narrow-spectrum antimicrobial group, based on whether they received broad-spectrum antimicrobials for more or less than 72 h, respectively. Differences in patient characteristics, background of infectious diseases and empirical antimicrobial administration, and outcomes between the two groups were compared using the chi-square tests (Monte Carlo method) for categorical variables and the Mann-Whitney U-test for continuous variables. We also conducted a logistic regression analysis to investigate the factors associated with the detection of new MDR bacteria. RESULTS: A total of 254 patients from 31 Japanese ICUs were included in the analysis, of whom 159 (62.6%) were included in the broad-spectrum antimicrobial group and 95 (37.4%) were included in the narrow-spectrum antimicrobial group. The detection of new MDR bacteria was significantly higher in the broad-spectrum antimicrobial group (11.9% vs. 4.2%, p = 0.042). Logistic regression showed that broad-spectrum antimicrobial continuation for more than 72 h (OR [odds ratio] 3.09, p = 0.047) and cerebrovascular comorbidity on ICU admission (OR 2.91, p = 0.041) were associated with the detection of new MDR bacteria. CONCLUSIONS: Among Japanese ICU patients treated with empirical antimicrobials, broad-spectrum antimicrobial usage for more than 72 h was associated with the increased detection of new MDR bacteria. Antimicrobial stewardship programs in ICUs should discourage the prolonged use of empirical broad-spectrum antimicrobial therapy. Trial registration ClinicalTrials.gov, NCT02920463, Registered 30 September 2016, https://clinicaltrials.gov/ct2/show/NCT02920463.

Objectives: This retrospective observational study investigated whether the degree of muscular echogenicity in patients admitted to the intensive care unit (ICU) could help with the early detection of ICU-acquired weakness (ICU-AW) and predict physical function at hospital discharge. Methods: Twenty-five patients who were mechanically ventilated for more than 48 h in the ICU were enrolled. We also enrolled 23 outpatients with nonmuscular diseases as the control group. The target sites for measuring muscular echogenicity were the upper arm and lower leg. First, the muscular echogenicity was compared between surviving nonsurgical patients admitted to the ICU and stable outpatients with nonmuscular diseases. Second, we investigated the relationship between muscular echogenicity and clinical features, e.g., the manual muscle test (MMT), Medical Research Council (MRC) sum score, and Functional Independence Measure (FIM). Results: Muscular echogenicity in the upper arm in the ICU group was significantly higher than that in the control group. In the ICU group, the degree of muscular echogenicity of the upper arm was inversely correlated with the MMT of elbow flexion (P=0.006; r=-0.532) and the MRC sum score (P=0.002; r=-0.591). However, muscular echogenicity of the upper arm did not correlate with functional FIM (P=0.100; r=-0.344) at hospital discharge. Conclusions: Critically ill patients can experience pathological muscle weakness associated with increased muscular echogenicity in the upper arm. Additionally, the degree of muscular echogenicity in the upper arm correlated with the MRC sum score and can facilitate early detection of ICU-AW. The relationship between echogenicity and functional outcome at discharge requires elucidation.

<title>Abstract</title><sec> <title>Background</title> Electrical cardioversion (ECV) is widely used to restore sinus rhythm in critically ill adult patients with atrial fibrillation, although its prognostic value is uncertain. This study aims to elucidate the clinical meaning of successful ECV. </sec><sec> <title>Methods</title> This is a sub-analysis of the AFTER-ICU study, a multicenter prospective study with a cohort of 423 adult non-cardiac patients with new-onset atrial fibrillation (AF). Patients that underwent ECV within 7 days after initial onset of AF were included in the sub-analysis. We compared intensive care unit (ICU) and overall hospital mortality, survival time within 30 days, cardiac rhythm at ICU discharge, and the length of ICU and overall hospital stay between patients whose sinus rhythm was restored immediately after the first ECV session (primary success group) and those in whom it was not restored (unsuccessful group). To find the factors related to the primary success of ECV, we also compared patient characteristics, the delivered energy, and pretreatment. </sec><sec> <title>Results</title> Sixty-five patients received ECV and were included in this study. Although 35 patients (54%) had primary success, recurrence of AF occurred in 24 of these patients (69%). At ICU discharge, three patients still had AF in the unsuccessful group, but no patients in the primary success group still had AF. ICU mortality was 34% in the primary success group and 17% in the unsuccessful group (<italic>P</italic> = 0.10). Survival time within 30 days did not differ between the groups. Delivered energy and pretreatment were not associated with primary success of ECV. </sec><sec> <title>Conclusions</title> The primary success rate of ECV for new-onset AF in adult non-cardiac ICU population was low, and even if it succeeded, the subsequent recurrence rate was high. Primary success of ECV did not affect the rate of mortality. Pretreatment and delivered energy were not associated with the primary success of ECV. </sec><sec> <title>Trial registration</title> UMIN clinical trial registry, the Japanese clinical trial registry (registration number: <ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000030333">UMIN000026401</ext-link>, March 31, 2017). </sec>

Recently, maintaining a certain oxygen saturation measured by pulse oximetry (SpO2) range in mechanically ventilated patients was recommended; attaching the INTELLiVENT-ASV to ventilators might be beneficial. We evaluated the SpO2 measurement accuracy of a Nihon Kohden and a Masimo monitor compared to actual arterial oxygen saturation (SaO2). SpO2 was simultaneously measured by a Nihon Kohden and Masimo monitor in patients consecutively admitted to a general intensive care unit and mechanically ventilated. Bland-Altman plots were used to compare measured SpO2 with actual SaO2. One hundred mechanically ventilated patients and 1497 arterial blood gas results were reviewed. Mean SaO2 values, Nihon Kohden SpO2 measurements, and Masimo SpO2 measurements were 95.7%, 96.4%, and 96.9%, respectively. The Nihon Kohden SpO2 measurements were less biased than Masimo measurements; their precision was not significantly different. Nihon Kohden and Masimo SpO2 measurements were not significantly different in the "SaO2 < 94%" group (P = 0.083). In the "94% ≤ SaO2 < 98%" and "SaO2 ≥ 98%" groups, there were significant differences between the Nihon Kohden and Masimo SpO2 measurements (P < 0.0001; P = 0.006; respectively). Therefore, when using automatically controlling oxygenation with INTELLiVENT-ASV in mechanically ventilated patients, the Nihon Kohden SpO2 sensor is preferable.Trial registration UMIN000027671. Registered 7 June 2017.

OBJECTIVES: Moral distress occurs when professionals cannot carry out what they believe to be ethically appropriate actions because of constraints or barriers. We aimed to assess the validity and reliability of the Japanese translation of the Measure of Moral Distress for Healthcare Professionals (MMD-HP). METHODS: We translated the questionnaire into Japanese according to the instructions of EORTC Quality of Life group translation manual. All physicians and nurses who were directly involved in patient care at nine departments of four tertiary hospitals in Japan were invited to a survey to assess the construct validity, reliability and factor structure. Construct validity was assessed with the relation to the intention to leave the clinical position, and internal consistency was assessed with Cronbach's alpha. Confirmatory factor analysis was conducted. RESULTS: 308 responses were eligible for the analysis. The mean total score of MMD-HP (range, 0-432) was 98.2 (SD, 59.9). The score was higher in those who have or had the intention to leave their clinical role due to moral distress than in those who do not or did not have the intention of leaving (mean 113.7 [SD, 61.3] vs. 86.1 [56.6], t-test p < 0.001). The confirmatory factor analysis and Cronbach's alpha confirmed the validity (chi-square, 661.9; CMIN/df, 2.14; GFI, 0.86; CFI, 0.88; CFI/TLI, 1.02; RMSEA, 0.061 [90%CI, 0.055-0.067]) and reliability (0.91 [95%CI, 0.89-0.92]) of the instrument. CONCLUSIONS: The translated Japanese version of the MMD-HP is a reliable and valid instrument to assess moral distress among physicians and nurses.

The original version of this article unfortunately contained incorrect data for the SOFA score in the Table 1. The number of missing data of this score presented in the manuscript was also incorrect. Because the authors failed to add the score of renal part for calculating SOFA scores for each patient, the SOFA score in the primary manuscript was lower than the correct data unintentionally. The SOFA score was not used in the multivariable analyses and was also not discussed in the manuscript. The authors apologize for the presentation of incorrect data. The corrected Table 1 can be found below. In the results section it should read: “Data were missing only for BMI (1 patient) and SOFA score (11 patients). (Table presented.).

BACKGROUND: Metabolic acidosis is a major complication of critical illness. However, its current epidemiology and its treatment with sodium bicarbonate given to correct metabolic acidosis in the ICU are poorly understood. METHOD: This was an international retrospective observational study in 18 ICUs in Australia, Japan, and Taiwan. Adult patients were consecutively screened, and those with early metabolic acidosis (pH < 7.3 and a Base Excess < -4 mEq/L, within 24-h of ICU admission) were included. Screening continued until 10 patients who received and 10 patients who did not receive sodium bicarbonate in the first 24 h (early bicarbonate therapy) were included at each site. The primary outcome was ICU mortality, and the association between sodium bicarbonate and the clinical outcomes were assessed using regression analysis with generalized linear mixed model. RESULTS: We screened 9437 patients. Of these, 1292 had early metabolic acidosis (14.0%). Early sodium bicarbonate was given to 18.0% (233/1292) of these patients. Dosing, physiological, and clinical outcome data were assessed in 360 patients. The median dose of sodium bicarbonate in the first 24 h was 110 mmol, which was not correlated with bodyweight or the severity of metabolic acidosis. Patients who received early sodium bicarbonate had higher APACHE III scores, lower pH, lower base excess, lower PaCO2, and a higher lactate and received higher doses of vasopressors. After adjusting for confounders, the early administration of sodium bicarbonate was associated with an adjusted odds ratio (aOR) of 0.85 (95% CI, 0.44 to 1.62) for ICU mortality. In patients with vasopressor dependency, early sodium bicarbonate was associated with higher mean arterial pressure at 6 h and an aOR of 0.52 (95% CI, 0.22 to 1.19) for ICU mortality. CONCLUSIONS: Early metabolic acidosis is common in critically ill patients. Early sodium bicarbonate is administered by clinicians to more severely ill patients but without correction for weight or acidosis severity. Bicarbonate therapy in acidotic vasopressor-dependent patients may be beneficial and warrants further investigation.

好中球・単球といった白血球は感染症・外傷などにおける初期応答で重要な役割を果たしている。血小板は核を有さない細胞で、血栓止血において不可欠な存在である。これらの2つの細胞は、体内で血小板白血球複合体を形成することで、炎症病態にかかわるといわれている。この炎症反応は、急性肺障害にも深く関連していることが基礎研究からも指摘されており、血小板白血球複合体をバイオマーカーとして利用する試みも行われている。炎症や肺障害の主たる原因となるこの血小板白血球複合体に対して、治療薬として抗血小板薬の有効性が研究されている。また、昨今日本を騒がせている新型コロナウイルス感染症(COVID-19)においても、血小板白血球複合体が炎症ならびに重症化に関与していると報告されており、この病態に対する抗血小板薬・抗凝固薬の有効性も検証されている。本稿では、血小板と白血球の相互作用による炎症反応や肺障害を生じるメカニクスの解説を行い、次に治療として薬剤的抑制が有効か検証する。最後にCOVID-19感染症における血小板白血球複合体の病態について、先行研究を踏まえて解説する。(著者抄録)

BACKGROUND: INTELLiVENT-ASV® (I-ASV) is a closed-loop ventilation mode that automatically controls the ventilation settings. Although a number of studies have reported the usefulness of I-ASV, the clinical situations in which it may be useful have not yet been clarified. We aimed to report our initial 3 years of experience using I-ASV, particularly the clinical conditions and the technical and organizational factors associated with its use. Furthermore, we evaluated the usefulness of I-ASV and determined the predictive factors for successful management with I-ASV. METHODS: This single-center, retrospective observational study included patients who were ventilated using the Hamilton G5® ventilator (Hamilton Medical AG, Rhäzüns, Switzerland) from January 2016 to December 2018. The patients were categorized into the "I-ASV success" group and "I-ASV failure" group (those receiving mechanical ventilation with I-ASV along with any other mode). Multivariate analysis was performed to identify factors associated with successful I-ASV management. RESULTS: Of the 189 patients, 135 (71.4%) were categorized into the I-ASV success group. In the I-ASV success group, the reasons for ICU admission included post-elective surgery (94.1%), post-emergent surgery (81.5%), and other medical reasons (55.6%). I-ASV failure was associated with a low P/F ratio (278 vs. 167, P = 0.0003) and high Acute Physiology and Chronic Health Evaluation (APACHE) II score (21 vs. 26, P < 0.0001). The main reasons for not using I-ASV included strong inspiratory effort and asynchrony. The APACHE II score was an independent predictive factor for successful management with I-ASV, with an odds ratio of 0.92 (95% confidential interval 0.87-0.96, P = 0.0006). The area under the receiver operating curve for the APACHE II score was 0.722 (cut-off: 24). CONCLUSIONS: In this study, we found that 71.4% of the fully mechanically ventilated patients could be managed successfully with I-ASV. The APACHE II score was an independent factor that could help predict the successful management of I-ASV. To improve I-ASV management, it is necessary to focus on patient-ventilator interactions.

Purpose The development of new-onset atrial fibrillation (AF) in critically ill patients may be associated with poor outcomes. However, it is unknown whether sustained new-onset AF contributes to worse outcome. The aim of this study was to assess whether sustained new-onset AF is associated with stroke and death and to look for a possible dose-response relationship between AF duration and death. Methods In a prospective cohort study conducted in 32 intensive care units in Japan from 2017 to 2018, we enrolled adult patients with new-onset AF. We compared patients with AF duration longer than 48 h with those with AF duration shorter than 48 h. To assess a dose-response relationship between AF duration and hospital mortality, we conducted landmark analysis and time-dependent Cox regression analysis. Results Among a total of 423 new-onset AF patients, hospital mortality was 25%, and the incidence of in-hospital stroke was 4.6%. AF duration longer than 48 h was not independently associated with hospital mortality (adjusted odds ratio: 1.52; 95% Confidence Interval: 0.87-2.64). The incidence of in-hospital stroke was 7.6% in patients with AF duration longer than 48 h and 3.8% in those with AF duration shorter than 48 h (p = 0.154). When analyzing time more continuously, we observed a time-dependent association between AF duration and hospital mortality (p = 0.005 by landmark analysis and p = 0.019 by Cox analysis). Conclusions Sustained new-onset AF was time-dependently associated with hospital mortality in ICU patients, albeit with some uncertainty since AF duration longer than 48 h was not independently associated with in-hospital death or stroke.

INTELLiVENT-ASV(I-ASV)は患者のSpO2とET CO2をモニタリングしながら、毎呼吸ごとに最適な換気を提供するclosed loop ventilationである。1つの換気モードで導入時から離脱評価まで、患者の呼吸状態に合わせて随時最適な換気を提供することが可能である。目標とする分時換気量のなかで1回換気量を低く管理し肺保護換気を遵守すること、吸入酸素濃度を最小化させることなど、患者にとっての診療の質を保つ一方、医療従事者の業務量軽減にも期待されている。導入しやすい患者は定時術後や肺に大きな問題がない症例であり、ARDSの急性期や人工呼吸から離脱困難な症例では難しいことが多い。本稿では、I-ASVのメカニズムから利点や注意点を臨床の視点から説明する。(著者抄録)

BACKGROUND: Altered coagulation and alveolar injury are the hallmarks of acute respiratory distress syndrome (ARDS). However, whether the biomarkers that reflect pathophysiology differ depending on the etiology of ARDS has not been examined. This study aimed to investigate the biomarker profiles of coagulopathy and alveolar epithelial injury in two subtypes of ARDS: patients with direct common risk factors (dARDS) and those with idiopathic or immune-related diseases (iARDS), which are classified as "ARDS without common risk factors" based on the Berlin definition. METHODS: This retrospective, observational study included adult patients who were admitted to the intensive care unit (ICU) at a university hospital with a diagnosis of ARDS with no indirect risk factors. Plasma biomarkers (thrombin-antithrombin complex [TAT], plasminogen activator inhibitor [PAI]-1, protein C [PC] activity, procalcitonin [PCT], surfactant protein [SP]-D, and KL-6) were routinely measured during the first 5 days of the patient's ICU stay. RESULTS: Among 138 eligible patients with ARDS, 51 were excluded based on the exclusion criteria (n = 41) or other causes of ARDS (n = 10). Of the remaining 87 patients, 56 were identified as having dARDS and 31 as having iARDS. Among the iARDS patients, TAT (marker of thrombin generation) and PAI-1 (marker of inhibited fibrinolysis) were increased, and PC activity was above normal. In contrast, PC activity was significantly decreased, and TAT or PAI-1 was present at much higher levels in dARDS compared with iARDS patients. Significant differences were also observed in PCT, SP-D, and KL-6 between patients with dARDS and iARDS. The receiver operating characteristic (ROC) analysis showed that areas under the ROC curve for PC activity, PAI-1, PCT, SP-D, and KL-6 were similarly high for distinguishing between dARDS and iARDS (PC 0.86, P = 0.33; PAI-1 0.89, P = 0.95; PCT 0.89, P = 0.66; and SP-D 0.88, P = 0.16 vs. KL-6 0.90, respectively). CONCLUSIONS: Coagulopathy and alveolar epithelial injury were observed in both patients with dARDS and with iARDS. However, their biomarker profiles were significantly different between the two groups. The different patterns of PAI-1, PC activity, SP-D, and KL-6 may help in differentiating between these ARDS subtypes.

BACKGROUND: Recent studies have suggested a low potential risk for contrast medium-induced kidney injury in patients with relatively normal renal function. However, whether contrast media cause additional deterioration of renal function in patients with acute kidney injury (AKI), including those with sepsis-associated AKI, remains unclear. This study aimed to evaluate the effect of contrast media on renal function and mortality in patients with sepsis who already had AKI. METHODS: We performed a propensity score-matched historical cohort study in the medico-surgical intensive care unit of Jichi Medical University Hospital. Adult patients who were diagnosed with sepsis and AKI were enrolled. Records from our sepsis database from 2011 to 2017 were examined. Septic patients with AKI who received contrast media within 24 h of admission (C group) were matched 1:1 with septic patients who did not receive contrast media (NC group). The primary outcome was deterioration of kidney function (DRF), which was defined as an elevation of serum creatinine levels (> 0.3 mg/dL or 1.5-fold from baseline) or induction of renal replacement therapy. RESULTS: A total of 339 septic patients with AKI were included. After propensity score adjustment, the DRF rate was similar between the C and NC groups (34.0% versus 35.0%; P = 1.00). The 7-day mortality (3.0% versus 6.0%; P = 0.50), 28-day mortality (9.2% versus 15.0%; P = 0.25), and 90-day mortality (25.8% versus 32.1%; P = 0.45) rates were comparable between the two groups. In propensity-adjusted subsets of a high-risk subset (AKI stages 2 and 3 on admission), the rate of DRF was also similar between the two groups. CONCLUSIONS: A single administration of contrast media was not associated with exacerbation of AKI or increased short/long-term mortality in patients with sepsis.

Purpose: To assess the predictive validity of a modified Sequential Organ Failure Assessment (SOFA) score, of which the renal component was replaced with Kidney Disease Improving Global Outcomes (KDIGO) classification of Acute Kidney Injury (AKI).Materials and methods: Using a prospective cohort study on AKI in Japan, we replaced the renal component of SOFA score with AKI stages according to the KDIGO criteria except that initiation of renal replacement therapy was assigned four points. We assessed the predictive validity of KDIGO-based SOFA score for hospital and ICU mortality by comparing the areas under the receiver operating characteristic curve (AUC) derived from logistic regression models with that of the original SOFA score.Results: 2292 patients were registered. Overall hospital mortality was 11.6%, and ICU mortality was 5.1%. KDIGO-based SOFA score was moderately correlated with APACHE II score (rho = 0.476). The AUC for hospital and ICU mortality of KDIGO-based and the original SOFA score were 0.749 vs 0.745 (p = .393) and 0.790 vs 0.791 (p = .900).Conclusions: The prognostic performance of KDIGO-based SOFA score was not superior but comparable to that of the original SOFA score. (C) 2019 Elsevier Inc. All rights reserved.

Since endothelial function is closely related to organ dysfunction in sepsis and the relationship among endothelial injury, organ dysfunction, and other biomarkers remains unclear, we aimed to evaluate the correlation among endothelial injury, organ dysfunction, and several biomarkers in patients with sepsis. Design: This was a retrospective observational study. Setting: The study was conducted in a university hospital with 14 mixed ICU beds. Patients: ICU patients with sepsis from June 2011 to December 2017 were enrolled in this study. Interventions: Endothelial biomarkers (soluble thrombomodulin, plasminogen activator inhibitor-1, and protein C) and markers of inflammation and coagulation were evaluated during the ICU stay. Sequential Organ Failure Assessment scores were assessed for 7 days after ICU admission to determine organ dysfunction. Variables were compared among five stratified groups according to the Sequential Organ Failure Assessment score (0-2, 3-5, 6-8, 9-12, and 13-24). Regression analysis and 95% CIs were used to evaluate trends in biomarkers. Measurements and Main Results: The patients were divided into five stratified groups (Sequential Organ Failure Assessment 0-2, n = 159 [20.5%]; Sequential Organ Failure Assessment 3-5, n = 296 [38.2%]; Sequential Organ Failure Assessment 6-8, n = 182 [23.5%]; Sequential Organ Failure Assessment 9-12, n = 75 [9.7%]; Sequential Organ Failure Assessment 13-24, n = 31 [4.0%]). Protein C activity was significantly correlated with the severity of organ dysfunction. It was lower on day 1, increased upon successful treatment, and was significantly higher in groups with lower Sequential Organ Failure Assessment scores. Conclusions: Trends and activity of protein C were superior in predicting organ dysfunction compared with other endothelial biomarkers. Monitoring the level of protein C activity is an ideal tool to monitor organ dysfunctions in patients with sepsis.

Background: We hypothesized that the use of actual body weight might lead to more frequent misdiagnosis of acute kidney injury (AKI) than when ideal body weight is used in underweight and/or obese patients. We examined which definition of body weight is most effective in establishing a urinary diagnosis of AKI in septic patients. Methods: Consecutive patients aged ≥ 20 years admitted to the intensive care unit of a university hospital between June 2011 and December 2016 were analyzed. Sepsis was defined in accordance with the Sepsis-3 criteria. AKI was defined as a urinary output of &lt 0.5 mL/kg/6h during intensive care unit stay. Patients were divided into one of four body mass index-based classes. The severity of illness and 90-day mortality were compared across the body mass index subgroups in patients diagnosed using the actual body weight or ideal body weight. Results: Of 5764 patients, 569 septic patients were analyzed. One hundred and fifty-three (26.9%) and 140 (24.6%) patients were diagnosed as having AKI using actual body weight and ideal body weight, respectively. There were no significant differences in the severity of illness among these groups. Also, 90-day mortality did not differ significantly among these groups. According to body mass index, 90-day mortality significantly differed in patients diagnosed using their actual body weights (underweight vs. normal vs. overweight vs. obese: 76.7% vs. 39.5% vs. 26.0% vs. 35.7%, P = 0.033). Conclusion: Generally, using actual body weight to calculate the weight-adjusted hourly urine output for diagnosing AKI increased the sensitivity compared to ideal body weight, irrespective of the severity of illness in septic patients. Delayed diagnosis, however, was more common among underweight patients in this situation, and clinicians should be cautious when diagnosing urinary AKI using actual body weight.

Background: Intravenous glycerol treatment, usually administered in the form of a 5% fructose solution, can be used to reduce intracranial pressure. The administered fructose theoretically influences blood lactate levels, although little is known regarding whether intravenous glycerol treatment causes transient hyperlactatemia. This study aimed to evaluate blood lactate levels in patients who received intravenous glycerol or mannitol. Methods: This single-center prospective observational study was performed at a 14-bed general intensive care unit between August 2016 and January 2018. Patients were excluded if they were < 20 years old or had pre-existing hyperlactatemia (blood lactate > 2.0 mmol/L). The included patients received intravenous glycerol or mannitol to reduce intracranial pressure and provided blood samples for lactate testing before and after the drug infusion (before the infusion and after 15 min, 30 min, 45 min, 60 min, 90 min, 120 min, and 150 min). Results: Among the 33 included patients, 13 patients received 200 mL of glycerol over 30 min, 13 patients received 200 mL of glycerol over 60 min, and 7 patients received 300 mL of mannitol over 60 min. Both groups of patients who received glycerol had significantly higher lactate levels than the mannitol group (2.8 mmol/L vs. 2.2 mmol/L vs. 1.6 mmol/L, P < 0.0001), with the magnitude of the increase in lactate levels corresponding to the glycerol infusion time. There were no significant inter-group differences in cardiac index, stroke volume, or stroke volume variation. In the group that received the 30-min glycerol infusion, blood lactate levels did not return to the normal range until after 120 min. Conclusions: Intravenous administration of glycerol leads to higher blood lactate levels that persist for up to 120 min. Although hyperlactatemia is an essential indicator of sepsis and/or impaired tissue perfusion, physicians should be aware of this phenomenon when assessing the blood lactate levels.

Introduction The pathogenesis of thrombocytopenia in patients with sepsis is not fully understood. The aims of this study were to investigate changes in thrombopoietic activity over time by using absolute immature platelet counts (AIPC) and to examine the impact of platelet production on thrombocytopenia and mortality in patients with sepsis. Methods This retrospective observational study included adult patients with sepsis admitted to the intensive care unit at a university hospital. Two hundred five consecutive sepsis patients were stratified into four groups according to nadir platelet count: severe (nadir 40×103/μL), moderate (41–80×103/μL), or mild thrombocytopenia (81–120×103/μL), or normal-increased platelet count (&gt 120×103/μL). The development of thrombocytopenia was assessed during the first week mortality was assessed at day 28. Result Of the 205 patients included, 61 (29.8%) developed severe thrombocytopenia. On admission, AIPC did not differ among the four groups. In patients with severe thrombocytopenia, AIPC decreased significantly from days 2 to 7, but remained within or above the normal range in the other three groups (overall group comparison, P&lt 0.0001). Multivariate analysis including coagulation biomarkers revealed that AIPC was independently associated with the development of severe thrombocytopenia (day 3 AIPC, odds ratio 0.49 [95% confidence interval (CI) 0.35–0.66], P&lt 0.0001 day 5 AIPC, 0.59 [95% CI 0.45–0.75], P&lt 0.0001). AIPC was a significant predictor of 28-day mortality in Cox hazard models adjusted for Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores (day 3 AIPC, hazard ratio 0.70 [95% CI 0.52–0.89], P = 0.0029 day 5 AIPC, 0.68 [95% CI 0.49–0.87], P = 0.0012). Conclusions Thrombopoietic activity was generally maintained in the acute phase of sepsis. However, a decrease in AIPC after admission was independently associated with the development of severe thrombocytopenia and mortality, suggesting the importance of suppressed thrombopoiesis in the pathophysiology of sepsis-induced thrombocytopenia.

Background: Endothelial activation and damage occur early during sepsis, with activated coagulopathy and playing a major role in the pathophysiology of sepsis-induced acute kidney injury (AKI). The aim of this study was to compare the various biomarkers of endothelial injury with the biomarkers of coagulation and inflammation and to determine a significant predictor of AKI in patients with sepsis. Methods: We conducted a single-center, retrospective, observational study on patients with sepsis fulfilling the Third International Consensus Definitions for Sepsis and Septic Shock criteria admitted to an adult intensive care unit (ICU) at a university hospital from June 2011 to December 2016. Levels of 13 biomarkers were measured on ICU admission, including markers of endothelial injury (soluble thrombomodulin [sTM], E-selectin, protein C, and plasminogen activator inhibitor-1 [PAI-1]) and markers of coagulation derangement (platelet count, fibrin degradation product [FDP], prothrombin time [PT], fibrinogen, α2-plasminogen inhibitor [α2-PI], antithrombin III [AT III], plasminogen, thrombin-antithrombin complex, and plasmin-α2-plasmin inhibitor complex). All patients with sepsis were reviewed, and the development of AKI was evaluated. Multivariate logistic regression analysis was performed to identify significant independent predictive factors for AKI. Results: Of the 514 patients admitted with sepsis, 351 (68.3%) developed AKI. Compared with the non-AKI group, all the endothelial biomarkers were significantly different in the AKI group (sTM [23.6 vs. 15.6 U/ml, P &lt 0.0001], E-selectin [65.5 vs. 46.2 ng/ml, P = 0.0497], PAI-1 [180.4 vs. 75.3 ng/ml, P = 0.018], and protein C [45.9 vs. 58.7 ng/ml, P &lt 0.0001]). Biomarkers of coagulopathy and inflammation, platelet counts, FDP, PT, α2-PI, AT III, plasminogen, and C-reactive protein were significantly different between the two groups. Multivariable logistic regression analysis showed that sTM was an independent predictive factor of AKI, with an AUROC of 0.758 (P &lt 0.0001). Conclusions: Endothelial biomarkers were significantly changed in the sepsis patients with AKI. Particularly, sTM was an independent predictive biomarker for the development of AKI that outperformed other coagulation and inflammation biomarkers as well as organ function in patients with sepsis.

近年、敗血症性ショックに対する体外式膜型人工肺(ECMO)の有用性が報告されている。ECMOの診療成績を向上させるためには、『どのような病態に対してECMOを導入するのか』を明確にする必要があるが、敗血症性ショックを対象とした場合、『薬物治療で対応できない重度低心機能による循環不全』が該当する。一度ECMOを導入すると前負荷が軽減されることで心機能が修飾されるため、ECMO導入前の段階で右心系を含めた低心機能の病態を把握することが重要である。またECMOからの離脱を成功させるために、ECMO離脱のロードマップを作成し、スタッフ間で情報共有する必要がある。今回、われわれの施設で経験した重度低心機能を伴う敗血症性ショックのためECMOを導入した生存症例と死亡症例を提示し、ECMO導入時や離脱時に対する右心評価の重要性やECMO導入にあたっての注意点に関して、文献的考察を踏まえて報告する。(著者抄録)

Background. The risk factors for the mortality rate of Pneumocystis jirovecii pneumonia (PCP) who required mechanical ventilation (MV) remained unknown. Methods. A retrospective chart review was performed of all PCP patients admitted to our intensive care unit and treated for acute hypoxemic respiratory failure to assess the risk factors for the high mortality. Results. Twenty patients without human immunodeficiency virus infection required mechanical ventilation; 19 received noninvasive ventilation; and 11 were intubated. PEEP was incrementally increased and titrated to maintain FIO2 as low as possible. No mandatory ventilation was used. Sixteen patients (80%) survived. Pneumothorax developed in one patient with rheumatoid arthritis (RA). Median PEEP level in the first 5 days was 10.0 cmH(2)O and not associated with death. Multivariate analysis showed the association of incidence of interstitial lung disease and increase in serum KL-6 with 90-day mortality. Conclusions. We found MV strategies to prevent pneumothorax including liberal use of noninvasive ventilation, and PEEP titration and disuse of mandatory ventilation may improve mortality in this setting. Underlying disease of interstitial lung disease was a risk factor and KL-6 may be a useful predictor associated with mortality in patients with RA. These findings will need to be validated in larger studies.

This multicentre, retrospective observational study was conducted from January 2010 to December 2010 to determine the optimal time for discontinuing continuous renal replacement therapy (CRRT) by evaluating factors predictive of successful discontinuation in patients with acute kidney injury. Analysis was performed for patients after CRRT was discontinued because of renal function recovery. Patients were divided into two groups according to the success or failure of CRRT discontinuation. In multivariate logistic regression analysis, urine output at discontinuation, creatinine level and CRRT duration were found to be significant variables (area under the receiver operating characteristic curve for urine output, 0.814). In conclusion, we found that higher urine output, lower creatinine and shorter CRRT duration were significant factors to predict successful discontinuation of CRRT.

Purpose: Low tidal volume ventilation improves the outcomes of acute respiratory distress syndrome (ARDS). However, no studies have investigated the use of a rescue therapy involving mechanical ventilation when low tidal volume ventilation cannot maintain homeostasis. Inverse ratio ventilation (IRV) is one candidate for such rescue therapy, but the roles and effects of IRV as a rescue therapy remain unknown. Methods: We undertook a retrospective review of the medical records of patients with ARDS who received IRV in our hospital from January 2007 to May 2014. Gas exchange, ventilation, and outcome data were collected and analyzed. Results: Pressure-controlled IRV was used for 13 patients during the study period. Volume- controlled IRV was not used. IRV was initiated on 4.4 ventilation days when gas exchange could not be maintained. IRV significantly improved the PaO2/FiO(2) from 76 +/- 27 to 208 +/- 91 mmHg without circulatory impairment. The mean duration of IRV was 10.5 days, and all survivors were weaned from mechanical ventilation and discharged. The 90-day mortality rate was 38.5 %. Univariate analysis showed that the duration of IRV was associated with the 90-day mortality rate. No patients were diagnosed with pneumothorax. Conclusions: Pressure-controlled IRV provided acceptable gas exchange without apparent complications and served as a successful bridge to conventional treatment when used as a rescue therapy for moderate to severe ARDS.

Background: Patient-ventilator asynchrony is a major cause of difficult weaning from mechanical ventilation. Neurally adjusted ventilatory assist (NAVA) is reported useful to improve the synchrony in patients with sustained low lung compliance. However, the role of NAVA has not been fully investigated. Case presentation: The patient was a 63-year-old Japanese man with acute respiratory distress syndrome secondary to respiratory infection. He was treated with extracorporeal membrane oxygenation for 7 days and survived. Dynamic compliance at withdrawal of extracorporeal membrane oxygenation decreased to 20 ml/cmH2O or less, but gas exchange was maintained by full support with assist/control mode. However, weaning from mechanical ventilation using a flow trigger failed repeatedly because of patient-ventilator asynchrony with hypercapnic acidosis during partial ventilator support despite using different types of ventilators and different trigger levels. Weaning using NAVA restored the regular respiration and stable and normal acid-base balance. Electromyographic analysis of the diaphragm clearly showed improved triggering of both the start and the end of spontaneous inspiration. Regional ventilation monitoring using electrical impedance tomography showed an increase in tidal volume and a ventilation shift to the dorsal regions during NAVA, indicating that NAVA could deliver gas flow to the dorsal regions to adjust for the magnitude of diaphragmatic excursion. NAVA was applied for 31 days, followed by partial ventilatory support with a conventional flow trigger. The patient was discharged from the intensive care unit on day 110 and has recovered enough to be able to live without a ventilatory support for 5 h per day. Conclusion: Our experience showed that NAVA improved not only patient-ventilator synchrony but also regional ventilation distribution in an acute respiratory distress patient with sustained low lung compliance.