Electrical Impedance Tomography-based Ventilation Patterns in Patients after Major Surgery.

Rationale: General anesthesia and mechanical ventilation have negative impacts on the respiratory system, causing heterogeneous distribution of lung aeration, but little is known about the ventilation patterns of postoperative patients and their association with clinical outcomes. Objectives: To clarify the phenotypes of ventilation patterns along a gravitational direction after surgery by using electrical impedance tomography (EIT) and to evaluate their association with postoperative pulmonary complications (PPCs) and other relevant clinical outcomes. Methods: Adult postoperative patients at high risk for PPCs, receiving mechanical ventilation on ICU admission (N = 128), were prospectively enrolled between November 18, 2021 and July 18, 2022. PPCs were prospectively scored until hospital discharge, and their association with phenotypes of ventilation patterns was studied. The secondary outcomes were the times to wean from mechanical ventilation and oxygen use and the length of ICU stay. Measurements and Main Results: Three phenotypes of ventilation patterns were revealed by EIT: phenotype 1 (32% [n = 41], a predominance of ventral ventilation), phenotype 2 (41% [n = 52], homogeneous ventilation), and phenotype 3 (27% [n = 35], a predominance of dorsal ventilation). The median PPC score was higher in phenotype 1 and phenotype 3 than in phenotype 2. The median time to wean from mechanical ventilation was longer in phenotype 1 versus phenotype 2. The median duration of ICU stay was longer in phenotype 1 versus phenotype 2. The median time to wean from oxygen use was longer in phenotype 1 and phenotype 3 than in phenotype 2. Conclusions: Inhomogeneous ventilation patterns revealed by EIT on ICU admission were associated with PPCs, delayed weaning from mechanical ventilation and oxygen use, and a longer ICU stay.

The arousal level of consciousness required for working memory performance: An anaesthesia study.

Regarding the stage of arousal level required for working memory to function properly, limited studies have been conducted on changes in working memory performance when the arousal level of consciousness decreases. This study aimed to experimentally clarify the stages of consciousness necessary for optimal working memory function. In this experiment, the sedation levels were changed step-by-step using anaesthesia, and the performance accuracy during the execution of working memory was assessed using a dual-task paradigm. Participants were required to categorize and remember words in a specific target category. Categorization performance was measured across four different sedative phases: before anaesthesia (baseline), and deep, moderate and light stages of sedation. Short-delay recognition tasks were performed under these four sedative stages, followed by long-delay recognition tasks after participants recovered from sedation. The results of the short-delay recognition task showed that the performance was lowest at the deep stage. The performance of the moderate stage was lower than the baseline. In the long-delay recognition task, the performance under moderate sedation was lower than that under baseline and light sedation. In addition, the performance under light sedation was lower than that under baseline. These results suggest that task performance becomes difficult under half sedation and that transferring information to long-term memory is difficult even under one-quarter sedation.

Validity Verification of Human Pose-Tracking Algorithms for Gait Analysis Capability.

Two-dimensional (2D) clinical gait analysis systems are more affordable and portable than contemporary three-dimensional (3D) clinical models. Using the Vicon 3D motion capture system as the standard, we evaluated the internal statistics of the Imasen and open-source OpenPose gait measurement systems, both designed for 2D input, to validate their output based on the similarity of results and the legitimacy of their inner statistical processes. We measured time factors, distance factors, and joint angles of the hip and knee joints in the sagittal plane while varying speeds and gaits during level walking in three in-person walking experiments under normal, maximum-speed, and tandem scenarios. The intraclass correlation coefficients of the 2D models were greater than 0.769 for all gait parameters compared with those of Vicon, except for some knee joint angles. The relative agreement was excellent for the time-distance gait parameter and moderate-to-excellent for each gait motion contraction range, except for hip joint angles. The time-distance gait parameter was high for Cronbach's alpha coefficients of 0.899-0.993 but low for 0.298-0.971. Correlation coefficients were greater than 0.571 for time-distance gait parameters but lower for joint angle parameters, particularly hip joint angles. Our study elucidates areas in which to improve 2D models for their widespread clinical application.

Reliability and validity of muscle activity analysis using wearable electromyographs.

[Purpose] The aim of this study was to develop a novel wearable surface electromyograph called NOK, and compare its reliability and validity to an existing electromyograph. [Participants and Methods] The study participants were 23 healthy university students (Seven males and 16 females; age 20.3 ± 1.1 years [mean ± standard deviation]; height 162.0 ± 6.7 cm; weight 58.4 ± 10.1 kg) who all gave informed written consent. The newly developed electromyograph (NOK) features a rubberized skin contact surface that requires no electrodes and allows the acquisition of up to 10 channels of muscle waveforms on a portable personal computer. After measuring maximal isometric elbow extension and flexion, we examined muscle waveforms during isometric contractions of elbow joint flexion and extension at approximately 50% of maximal voluntary contraction using both NOK and Delsys electromyographs and compared the results of the two devices. [Results] We found a significant moderate correlation between the measurements by the two devices for biceps and triceps. The measurements by the two devices also showed strong measure-retest reliability. Systematic errors were observed for elbow flexion and extension in the two measurements, indicating limited agreement between the two measurement methods. [Conclusion] Although the new device also has high repeatability and reliability, it is unsuitable for analyzing detailed muscle activity. However, since it can measure up to 10 channels of muscle activity, it is expected to be used in the rehabilitation and sports field in the future.

Factors influencing the prognosis of patients with acute cerebral infarction who received usual care: a multicenter prospective cohort study.

[Purpose] The prognostic factors for patients with acute stroke who received usual care (mobilization ≥48 h after admission) remain unclear. This study aimed to investigate the prognostic factors that predict functional outcomes using evaluations performed immediately after onset in patients with acute cerebral infarction who received usual care from admission until discharge. [Participants and Methods] Participants with acute cerebral infarction admitted to five acute care hospitals in Tokyo and Saitama, Japan and prescribed physical therapy were included. Participants information, functional evaluations, and progress were recorded during the first physical therapy session, mobilization, and discharge. Participants who received usual care were assigned to either the good- or poor-outcome group based on the Modified Rankin Scale at discharge. [Results] In total, 161 Participants receiving usual care (mobilization ≥48 h after admission) were included. Reinfarction and the First National Institutes of Health Stroke Scale score were identified as independent predictors of functional outcome at hospital discharge in participants who received usual care (median, 22.0 d). The cutoff NIHSS score was 4. [Conclusion] Our results provided evidence that the National Institutes of Health Stroke Scale score and reinfarction are useful predictors of functional outcomes in participants who received usual care.

Asynchrony Injures Lung and Diaphragm in Acute Respiratory Distress Syndrome.

OBJECTIVES: Patient-ventilator asynchrony is often observed during mechanical ventilation and is associated with higher mortality. We hypothesized that patient-ventilator asynchrony causes lung and diaphragm injury and dysfunction. DESIGN: Prospective randomized animal study. SETTING: University research laboratory. SUBJECTS: Eighteen New Zealand White rabbits. INTERVENTIONS: Acute respiratory distress syndrome (ARDS) model was established by depleting surfactants. Each group (assist control, breath stacking, and reverse triggering) was simulated by phrenic nerve stimulation. The effects of each group on lung function, lung injury (wet-to-dry lung weight ratio, total protein, and interleukin-6 in bronchoalveolar lavage), diaphragm function (diaphragm force generation curve), and diaphragm injury (cross-sectional area of diaphragm muscle fibers, histology) were measured. Diaphragm RNA sequencing was performed using breath stacking and assist control ( n = 2 each). MEASUREMENTS AND MAIN RESULTS: Inspiratory effort generated by phrenic nerve stimulation was small and similar among groups (esophageal pressure swing ≈ -2.5 cm H 2 O). Breath stacking resulted in the largest tidal volume (>10 mL/kg) and highest inspiratory transpulmonary pressure, leading to worse oxygenation, worse lung compliance, and lung injury. Reverse triggering did not cause lung injury. No asynchrony events were observed in assist control, whereas eccentric contractions occurred in breath stacking and reverse triggering, but more frequently in breath stacking. Breath stacking and reverse triggering significantly reduced diaphragm force generation. Diaphragmatic histology revealed that the area fraction of abnormal muscle was ×2.5 higher in breath stacking (vs assist control) and ×2.1 higher in reverse triggering (vs assist control). Diaphragm RNA sequencing analysis revealed that genes associated with muscle differentiation and contraction were suppressed, whereas cytokine- and chemokine-mediated proinflammatory responses were activated in breath stacking versus assist control. CONCLUSIONS: Breath stacking caused lung and diaphragm injury, whereas reverse triggering caused diaphragm injury. Thus, careful monitoring and management of patient-ventilator asynchrony may be important to minimize lung and diaphragm injury from spontaneous breathing in ARDS.

Personalized ventilatory strategy based on lung recruitablity in COVID-19-associated acute respiratory distress syndrome: a prospective clinical study.

BACKGROUND: Heterogeneity is an inherent nature of ARDS. Recruitment-to-inflation ratio has been developed to identify the patients who has lung recruitablity. This technique might be useful to identify the patients that match specific interventions, such as higher positive end-expiratory pressure (PEEP) or prone position or both. We aimed to evaluate the physiological effects of PEEP and body position on lung mechanics and regional lung inflation in COVID-19-associated ARDS and to propose the optimal ventilatory strategy based on recruitment-to-inflation ratio. METHODS: Patients with COVID-19-associated ARDS were consecutively enrolled. Lung recruitablity (recruitment-to-inflation ratio) and regional lung inflation (electrical impedance tomography [EIT]) were measured with a combination of body position (supine or prone) and PEEP (low 5 cmH2O or high 15 cmH2O). The utility of recruitment-to-inflation ratio to predict responses to PEEP were examined with EIT. RESULTS: Forty-three patients were included. Recruitment-to-inflation ratio was 0.68 (IQR 0.52-0.84), separating high recruiter versus low recruiter. Oxygenation was the same between two groups. In high recruiter, a combination of high PEEP with prone position achieved the highest oxygenation and less dependent silent spaces in EIT (vs. low PEEP in both positions) without increasing non-dependent silent spaces in EIT. In low recruiter, low PEEP in prone position resulted in better oxygenation (vs. both PEEPs in supine position), less dependent silent spaces (vs. low PEEP in supine position) and less non-dependent silent spaces (vs. high PEEP in both positions). Recruitment-to-inflation ratio was positively correlated with the improvement in oxygenation and respiratory system compliance, the decrease in dependent silent spaces, and was inversely correlated with the increase in non-dependent silent spaces, when applying high PEEP. CONCLUSIONS: Recruitment-to-inflation ratio may be useful to personalize PEEP in COVID-19-associated ARDS. Higher PEEP in prone position and lower PEEP in prone position decreased the amount of dependent silent spaces (suggesting lung collapse) without increasing the amount of non-dependent silent spaces (suggesting overinflation) in high recruiter and in low recruiter, respectively.

Time definition of reintubation most relevant to patient outcomes in critically ill patients: a multicenter cohort study.

BACKGROUND: Reintubation is a common complication in critically ill patients requiring mechanical ventilation. Although reintubation has been demonstrated to be associated with patient outcomes, its time definition varies widely among guidelines and in the literature. This study aimed to determine the association between reintubation and patient outcomes as well as the consequences of the time elapsed between extubation and reintubation on patient outcomes. METHODS: This was a multicenter retrospective cohort study of critically ill patients conducted between April 2015 and March 2021. Adult patients who underwent mechanical ventilation and extubation in intensive care units (ICUs) were investigated utilizing the Japanese Intensive Care PAtient Database. The primary and secondary outcomes were in-hospital and ICU mortality. The association between reintubation and clinical outcomes was studied using Cox proportional hazards analysis. Among the patients who underwent reintubation, a Cox proportional hazard analysis was conducted to evaluate patient outcomes according to the number of days from extubation to reintubation. RESULTS: Overall, 184,705 patients in 75 ICUs were screened, and 1849 patients underwent reintubation among 48,082 extubated patients. After adjustment for potential confounders, multivariable analysis revealed a significant association between reintubation and increased in-hospital and ICU mortality (adjusted hazard ratio [HR] 1.520, 95% confidence interval [CI] 1.359-1.700, and adjusted HR 1.325, 95% CI 1.076-1.633, respectively). Among the reintubated patients, 1037 (56.1%) were reintubated within 24 h after extubation, 418 (22.6%) at 24-48 h, 198 (10.7%) at 48-72 h, 111 (6.0%) at 72-96 h, and 85 (4.6%) at 96-120 h. Multivariable Cox proportional hazard analysis showed that in-hospital and ICU mortality was highest in patients reintubated at 72-96 h (adjusted HR 1.528, 95% CI 1.062-2.197, and adjusted HR 1.334, 95% CI 0.756-2.352, respectively; referenced to reintubation within 24 h). CONCLUSIONS: Reintubation was associated with a significant increase in in-hospital and ICU mortality. The highest mortality rates were observed in patients who were reintubated between 72 and 96 h after extubation. Further studies are warranted for the optimal observation of extubated patients in clinical practice and to strengthen the evidence for mechanical ventilation.

Control of blood glucose levels by an artificial pancreas in patients with severe coronavirus disease 2019 pneumonia.

BACKGROUND: Many patients with severe coronavirus disease 2019 (COVID-19) pneumonia experience hyperglycemia. It is often difficult to control blood glucose (BG) levels in such patients using standard intravenous insulin infusion therapy. Therefore, we used an artificial pancreas. This study aimed to compare the BG status of the artificial pancreas with that of standard therapy. METHODS: Fifteen patients were included in the study. BG values and the infusion speed of insulin and glucose by the artificial pancreas were collected. Arterial BG and administration rates of insulin, parenteral sugar, and enteral sugar were recorded during the artificial pancreas and standard therapy. The target BG level was 200 mg/dl. RESULTS: Arterial BG was highly correlated with BG data from the artificial pancreas. A higher BG slightly increased the difference between the BG data from the artificial pancreas and arterial BS. No significant difference in arterial BG was observed between the artificial pancreas and standard therapy. However, the standard deviation with the artificial pancreas was smaller than that under standard therapy (p < 0.0001). More points within the target BG range were achieved with the artificial pancreas (180-220 mg/dl) than under standard therapy. The hyperglycemic index of the artificial pancreas (8.7 ± 15.6 mg/dl) was lower than that of standard therapy (16.0 ± 21.5 mg/dl) (p = 0.0387). No incidence of hypoglycemia occurred under the artificial pancreas. CONCLUSIONS: The rate of achieving target BG was higher using artificial pancreas than with standard therapy. An artificial pancreas helps to control BG in critically ill patients.

Noninvasive blood pressure measurement in patients with continuous-flow left ventricular assist devices.

Oscillatory blood pressure (OBP) with a slow cuff-deflation system has been proposed as noninvasive measurement of mean arterial pressure (MAP) in patients with continuous-flow left ventricular assist devices (LVADs). However, the challenge is that the measurement is not obtainable in certain patients. We hypothesized that the combined use of color Doppler imaging during OBP measurement (CDBP) could derive MAP accurately. We conducted a prospective observational study in critically ill patients (30 patients with continuous-flow LVADs and 30 control patients without LVADs). Triplicate OBP and CDBP measurements were performed and invasive blood pressure (IBP) was recorded. The overall success rate of OBP was 63.3% in the LVAD group and 98.9% in the control group. The CDBP was successfully obtained in 100% of all study patients. The CDBP in the LVAD group was closest to the MAP of measured IBP, while that in the control group was closest to the systolic IBP. The mean absolute differences in OBP and CDBP from the closest IBP were similar in both the control and LVAD groups. In nonpulsatile LVAD patients with a pulse pressure IBP < 10 mmHg, the success rate of OBP measurement was only 10.0%, and CDBP showed significantly reduced error in MAP measurement (mean absolute difference: OBP 23.2 ± 8.7 vs CDBP 5.2 ± 3.6 mmHg, p < 0.001). The validity of OBP measurement with a slow cuff-deflation system limited particularly in nonpulsatile LVAD patients. The concurrent use of color Doppler imaging is encouraged for more accurate measurement of MAP in patients with continuous-flow LVADs.

Predictive factors for walking in acute stroke patients: a multicenter study using classification and regression tree analysis.

[Purpose] Walking ability should be predicted as early as possible in acute stroke patients. The purpose is to construct a prediction model for independent walking from bedside assessments using classification and regression tree analysis. [Participants and Methods] We conducted a multicenter case-control study with 240 stroke patients. Survey items included age, gender, injured hemisphere, the National Institute of Health Stroke Scale, the Brunnstrom Recovery Stage for lower extremities, and "turn over from a supine position" from the Ability for Basic Movement Scale. The National Institute of Health Stroke Scale items, such as language, extinction, and inattention, were grouped under higher brain dysfunction. We used the Functional Ambulation Categories to classify patients into independent (four or more the Functional Ambulation Categories; n=120) and dependent (three or fewer the Functional Ambulation Categories; n=120) walking groups. A classification and regression tree analysis was used to create a model to predict independent walking. [Results] The Brunnstrom Recovery Stage for lower extremities, "turn over from a supine position" from the Ability for Basic Movement Scale, and higher brain dysfunction were the splitting criteria for classifying patients into four categories: Category 1 (0%), severe motor paresis; Category 2 (10.0%), mild motor paresis and could not turn over; Category 3 (52.5%), with mild motor paresis, could turn over, and had higher brain dysfunction; and Category 4 (82.5%), with mild motor paresis, could turn over, and no higher brain dysfunction. [Conclusion] We constructed a useful prediction model for independent walking based on the three criteria.

Prone Position Minimizes the Exacerbation of Effort-dependent Lung Injury: Exploring the Mechanism in Pigs and Evaluating Injury in Rabbits.

BACKGROUND: Vigorous spontaneous effort can potentially worsen lung injury. This study hypothesized that the prone position would diminish a maldistribution of lung stress and inflation after diaphragmatic contraction and reduce spontaneous effort, resulting in less lung injury. METHODS: A severe acute respiratory distress syndrome model was established by depleting surfactant and injurious mechanical ventilation in 6 male pigs ("mechanism" protocol) and 12 male rabbits ("lung injury" protocol). In the mechanism protocol, regional inspiratory negative pleural pressure swing (intrabronchial balloon manometry) and the corresponding lung inflation (electrical impedance tomography) were measured with a combination of position (supine or prone) and positive end-expiratory pressure (high or low) matching the intensity of spontaneous effort. In the lung injury protocol, the intensities of spontaneous effort (esophageal manometry) and regional lung injury were compared in the supine position versus prone position. RESULTS: The mechanism protocol (pigs) found that in the prone position, there was no ventral-to-dorsal gradient in negative pleural pressure swing after diaphragmatic contraction, irrespective of the positive end-expiratory pressure level (-10.3 ± 3.3 cm H2O vs. -11.7 ± 2.4 cm H2O at low positive end-expiratory pressure, P = 0.115; -10.4 ± 3.4 cm H2O vs. -10.8 ± 2.3 cm H2O at high positive end-expiratory pressure, P = 0.715), achieving homogeneous inflation. In the supine position, however, spontaneous effort during low positive end-expiratory pressure had the largest ventral-to-dorsal gradient in negative pleural pressure swing (-9.8 ± 2.9 cm H2O vs. -18.1 ± 4.0 cm H2O, P < 0.001), causing dorsal overdistension. Higher positive end-expiratory pressure in the supine position reduced a ventral-to-dorsal gradient in negative pleural pressure swing, but it remained (-9.9 ± 2.8 cm H2O vs. -13.3 ± 2.3 cm H2O, P < 0.001). The lung injury protocol (rabbits) found that in the prone position, spontaneous effort was milder and lung injury was less without regional difference (lung myeloperoxidase activity in ventral vs. dorsal lung, 74.0 ± 30.9 µm · min-1 · mg-1 protein vs. 61.0 ± 23.0 µm · min-1 · mg-1 protein, P = 0.951). In the supine position, stronger spontaneous effort increased dorsal lung injury (lung myeloperoxidase activity in ventral vs. dorsal lung, 67.5 ± 38.1 µm · min-1 · mg-1 protein vs. 167.7 ± 65.5 µm · min-1 · mg-1 protein, P = 0.003). CONCLUSIONS: Prone position, independent of positive end-expiratory pressure levels, diminishes a maldistribution of lung stress and inflation imposed by spontaneous effort and mitigates spontaneous effort, resulting in less effort-dependent lung injury.

Trends in survival during the pandemic in patients with critical COVID-19 receiving mechanical ventilation with or without ECMO: analysis of the Japanese national registry data.

BACKGROUND: The survival rate of patients with critical coronavirus disease-19 (COVID-19) over time is inconsistent in different settings. In Japan, a national database was organized to monitor and share the patient generation across the country in an immediate response to the COVID-19 pandemic. This study aimed to evaluate changes in survival over time and the prognostic factors in critical COVID-19 patients receiving mechanical ventilation with/without extracorporeal membrane oxygenation (ECMO) using the largest database in Japan. METHODS: This is a prospective observational cohort study of patients admitted to intensive care units in Japan with fatal COVID-19 pneumonia receiving mechanical ventilation and/or ECMO. We developed a prospective nationwide registry covering > 80% of intensive care units in Japan, and analyzed the association between patients' backgrounds, institutional ECMO experience, and timing of treatment initiation and prognosis between February 2020 and November 2021. Prognostic factors were evaluated by Kaplan-Meier analysis and Cox proportional hazards analysis. RESULTS: A total of 9418 patients were ventilated, of whom 1214 (13%) received ECMO. The overall survival rate for ventilated patients was 79%, 65% for those receiving ECMO. There have been five outbreaks in Japan to date. The survival rate of ventilated patients increased from 76% in the first outbreak to 84% in the fifth outbreak (p < 0.001). The survival rate of ECMO patients remained unchanged at 60-68% from the first to fifth outbreaks (p = 0.084). Age of ≥ 59 (hazard ratio [HR] 2.17; 95% confidence interval [CI] 1.76-2.68), ventilator days of ≥ 3 before starting ECMO (HR 1.91; 95% CI 1.57-2.32), and institutional ECMO experiences of ≥ 11 (HR 0.70; 95% CI 0.58-0.85) were independent prognostic factors for ECMO. CONCLUSIONS: During five COVID-19 outbreaks in Japan, the survival rate of ventilated patients tended to have gradually improved, and that of ECMO patients did not deteriorate. Older age, longer ventilator days before starting ECMO, and fewer institutional ECMO experiences may be independent prognostic factors for critical COVID-19 patients receiving ECMO.

Ivermectin administration is associated with lower gastrointestinal complications and greater ventilator-free days in ventilated patients with COVID-19: A propensity score analysis.

INTRODUCTION: COVID-19 patients have been reported to have digestive symptoms with poor outcome. Ivermectin, an antiparasitic drug, has been used in COVID-19 patients. The objective of this study was to evaluate whether ivermectin has effects on gastrointestinal complications and ventilator-free days in ventilated patients with COVID-19. METHODS: COVID-19 patients who were mechanically ventilated in the ICU were included in this study. The ventilated patients who received ivermectin within 3 days after admission were assigned to the Ivermectin group, and the others were assigned to the Control group. Patients in the Ivermectin group received ivermectin 200 µg/kg via nasal tube. The incidence of gastrointestinal complications and ventilator-free days within 4 weeks from admission were evaluated as clinical outcomes using a propensity score with the inverse probability weighting method. RESULTS: We included 88 patients in this study, of whom 39 patients were classified into the Ivermectin group, and 49 patients were classified into the Control group. The hazard ratio for gastrointestinal complications in the Ivermectin group as compared with the Control group was 0.221 (95% confidence interval [CI], 0.057 to 0.855; p = 0.029) in a Cox proportional-hazard regression model. The odds ratio for ventilator-free days as compared with the Control group was 1.920 (95% CI, 1.076 to 3.425; p = 0.027) in a proportional odds logistic regression model. CONCLUSIONS: Ivermectin improved gastrointestinal complications and the number of ventilator-free days in severe COVID-19 patients undergoing mechanical ventilation. Prevention of gastrointestinal symptoms by SARS-Cov-2 might be associated with COVID-19 outcome.

Positive end-expiratory pressure and prone position alter the capacity of force generation from diaphragm in acute respiratory distress syndrome: an animal experiment.

BACKGROUND: Spontaneous breathing potentially injures lungs and diaphragm when spontaneous effort is vigorous in acute respiratory distress syndrome (ARDS) while immobility also has risks of Intensive Care Unit (ICU) acquired weakness and diaphragm atrophy. Thus, ventilatory strategy to mitigate strong spontaneous effort should be promptly established without a systemic use of neuromuscular blocking agent. Here, we investigated the impacts of positive end-expiratory pressure (PEEP) and body position on the capacity of force generation from diaphragm following bilateral phrenic nerve stimulations in a rabbit ARDS model. METHODS: Using lung-injured rabbits, we measured 1) transdiaphragmatic pressure by bilateral phrenic nerve stimulation and 2) end-expiratory lung volume using computed tomography, under two different levels of PEEP (high, low) and body positions (supine, prone). RESULTS: Overall, transdiaphragmatic pressure was the highest at low PEEP in supine position and the lowest at high PEEP in prone position. Compared to values in low PEEP + supine, transdiaphragmatic pressure was significantly reduced by either prone alone (the same PEEP) or increasing PEEP alone (the same position) or both combinations. End-expiratory lung volume was significantly increased with increasing PEEP in both positions, but it was not altered by body position. INTERPRETATION: The capacity of force generation from diaphragm was modulated by PEEP and body position during mechanical ventilation in ARDS. Higher PEEP or prone position per se or both was effective to decrease the force generation from diaphragm.

Effects of standing and walking training using a laser pointer based on stimulus-driven attention for behavioural outcome in spatial neglect: A single-case study.

The therapy for unilateral spatial neglect (USN) is unclear. This case report investigated the effect of standing and walking training using a laser pointer based on stimulus-driven attention for USN. The patient was a right-handed 79-year-old man with cardiogenic cerebral embolism in the right middle and posterior cerebral arteries. Initially, we evaluated the absence of hemiparalysis in the lower limb and sensory disorder; almost all daily activities were performed independently. Intervention effects were verified using the BABA method. The course of the four phases (B1, A1, B2, A2) was conducted for 5 days. In the B1 and B2 phases, standing and walking training using a laser pointer was performed additionally to conventional physical therapy. Outcomes were measured using the Behavioural Inattention Test conventional subtest (BIT-c), Catherine Bergego Scale (CBS), and modified Posner task (MPT). The BIT-c remained unchanged in each phase. CBS scores improved after B1 and B2. In the MPT, the reaction time in the left space reduced after B1 and B2 compared with those in the A1 and A2 control phases. In this case, training may have contributed to the improvement in the response to the neglected space and behavioural assessment of USN.

Anesthesia and surgery induce a functional decrease in excitatory synaptic transmission in prefrontal cortex neurons, and intraoperative administration of dexmedetomidine does not elicit the synaptic dysfunction.

Postoperative delirium (POD), a syndrome of confusion and inattention, frequently occurs after anesthesia and surgery. The prefrontal cortex (PFC) plays key roles in executive functions and cognitive controls. However, the neuropathogenesis of POD in the PFC remains largely unknown. We investigated whether anesthesia and surgery induced neurofunctional changes in the mouse PFC. After laparotomy was performed under isoflurane anesthesia, PFC neuronal activities were compared at the synaptic level using whole-cell patch-clamp recordings. A battery of behavioral tests measuring natural and learned behaviors, and effects of intraoperative dexmedetomidine were also examined. In the anesthesia/surgery group showing changes in natural and learned behaviors, the frequency of excitatory synaptic responses in PFC pyramidal neurons was decreased after the surgery without any changes in the response kinetics. On the other hand, neuronal intrinsic properties and inhibitory synaptic responses were not changed. In the anesthesia/surgery group administered intraoperative dexmedetomidine, the excitatory synaptic transmission and the behaviors were not altered. These results suggest that anesthesia and surgery induce a functional reduction selectively in the PFC excitatory synaptic transmission, and intraoperative dexmedetomidine inhibits the plastic change in the PFC excitatory synaptic input.

Monitoring the patient for a safe-assisted ventilation.

PURPOSE OF REVIEW: A growing evidence shows that injurious spontaneous breathing, either too weak or too strong, may injure lung and diaphragm. The purpose of review is to understand why we need monitoring for safe spontaneous breathing, and to know the target value of each monitoring to preserve safe spontaneous breathing during assisted ventilation. RECENT FINDINGS: Lung protection sometimes goes counter to diaphragm protection. For instance, silence of respiratory muscle activity is necessary to minimize lung injury from vigorous spontaneous effort in acute respiratory distress syndrome, but it may also have a risk of diaphragm atrophy. Thus, our current goal is to preserve spontaneous breathing activity at modest level during assisted ventilation. To achieve this goal, several monitoring/techniques are now available at the bedside (e.g., plateau pressure measurement, airway occlusion pressure, end-expiratory airway occlusion, esophageal balloon manometry, electrical impedance tomography). The target value of each monitoring is vigorously being investigated, facilitating 'safe' spontaneous breathing effort from the perspective of lung and diaphragm protection. SUMMARY: We summarize why we need monitoring for safe spontaneous breathing during assisted ventilation and what the target value of each monitoring is to facilitate 'safe' spontaneous breathing during assisted ventilation.

Examination of Rehabilitation Intensity According to Severity of Acute Stroke: A Retrospective Study.

OBJECTIVES: To investigate the intensity and effectiveness of rehabilitation in acute stroke patients according to the severity of functional impairments in them. MATERIALS AND METHODS: This retrospective cohort study included 294 patients with acute hemispheric stroke admitted to three acute-care hospitals who subsequently underwent an inpatient rehabilitation program. Stroke severity was classified according to neurological deficits and trunk dysfunction. The following data were obtained from medical records: age, sex, stroke type, lesion side, hospitalization duration, initial functional status determined using the National Institutes of Health Stroke Scale, rehabilitation start date, first day out of bed after admission, total treatment duration, total number of treatment sessions, rehabilitation implementation rate between start of rehabilitation and discharge, trunk control test and Barthel Index score on the first day out of bed after admission and discharge, and post-discharge outcomes. Hierarchical cluster analysis was performed with clusters categorized using the National Institutes of Health Stroke Scale and trunk control test scores. Variables were compared using the Kruskal-Wallis test, and Dunn's nonparametric comparison test was performed for post-hoc analysis to determine differences between clusters. RESULTS: The National Institutes of Health Stroke Scale and trunk control test showed a significant correlation (r = -0.816, p < 0.01) using which cluster analysis identified three clusters. Rehabilitation showed a ceiling effect in patients with mild stroke and a floor effect in patients with severe stroke. CONCLUSION: These results may guide the determination of rehabilitation intensity with reference to the severity of neurological deficits and trunk dysfunction.

Factors Influencing Sitting Ability During the Acute Post-Stroke Phase: A Multicenter Prospective Cohort Study in Japan.

OBJECTIVES: Sitting ability during the acute phase after stroke is a useful indicator of functional outcomes; however, factors that affect this ability have not been evaluated. Therefore, this study aimed to identify and evaluate factors that affect sitting ability in the acute phase after stroke. MATERIALS AND METHODS: This multicenter prospective cohort study included hemispheric stroke patients who underwent an inpatient rehabilitation program after acute stroke from five acute care hospitals. The effect of age, sex, lesion side, etiology, consciousness disorder, stroke and dementia history, stroke-related complications, National Institutes of Health Stroke Scale score, hemiparalysis, turn-over movement from the supine position and sit-up movement, and Scale for Contraversive Pushing on the "remain sitting" item in the revised version of the Ability of Basic Movement Scale at the time of acute hospital discharge were investigated. Factors affecting sitting ability were identified using binomial logistic regression analysis. RESULTS: We included 293 stroke patients. Age (odds ratio: 0.943, 95% confidence interval: 0.910-0.977, p=0.001), National Institutes of Health Stroke Scale score (odds ratio: 0.862, 95% confidence interval: 0.811-0.916, p<0.001), and Scale for Contraversive Pushing score (odds ratio: 0.543, 95% confidence interval: 0.419-0.705, p<0.001) were identified as independent predictors of sitting ability at the time of hospital discharge (median; 23.0 days). CONCLUSIONS: Older patients and those with high Scale for Contraversive Pushing and National Institutes of Health Stroke Scale scores experienced difficulties in regaining sitting ability. These results may guide physical therapy for patients with impaired sitting ability due to hemispheric stroke.