Published papers

© 2018, The Author(s). Short-duration spaceflight induces an approximately 10% reduction in plasma volume, which leads to mild volume depletion. In a previous study, we found that mild volume depletion improved dynamic cerebral autoregulation. However, the effect of mild volume depletion on intracranial pressure (ICP) remains unknown. Therefore, we estimated ICP noninvasively (nICP), and calculated two indices relating to ICP, the cerebral artery compliance and the cerebral blood flow pulsatility index (PI), to examine whether ICP would decrease due to a mild decrement in plasma volume. In our previous experiment, fourteen subjects were administered 0.2 mg/kg of furosemide in a supine position to simulate an approximately 10% reduction in plasma volume induced by short-duration spaceflight. We re-analyzed the cerebral blood flow velocity waveform from the middle cerebral artery obtained by transcranial Doppler and the arterial blood pressure waveform at the radial artery obtained by tonometry to estimate nICP and to calculate cerebral artery compliance and PI using mathematical analysis based on an intracranial hydraulic model. All indices were compared between before and after furosemide administration. There were no significant changes in nICP and cerebral artery compliance. However, PI decreased significantly from before to after furosemide administration (0.78 ± 0.10 to 0.74 ± 0.09, p = 0.009). Decreases in ICP were not observed during the 10% reduction in plasma volume. Although cerebral artery compliance did not change, PI decreased significantly. These findings suggest that the impedance of distal cerebral arteries would be reduced in response to mild decreases in plasma volume induced by short-duration spaceflight.

© 2018 The Author(s). Posterior spinal fusion for adolescent idiopathic scoliosis is one of the most invasive surgical procedures performed in children and adolescents. Because of the extensive surgical incision and massive tissue trauma, posterior spinal fusion causes severe postoperative pain. Intravenous patient-controlled analgesia with opioids has been the mainstay of postoperative pain management in these patients. However, the use of systemic opioids is sometimes limited by opioid-related side effects, resulting in poor analgesia. To improve pain management while reducing opioid consumption and opioid-related complications, concurrent use of analgesics and analgesic modalities with different mechanisms of action seems to be rational. The efficacy of intrathecal opioids and nonsteroidal anti-inflammatory drugs as components of multimodal analgesia in scoliosis surgery has been well established. However, there is either controversy or insufficient evidence regarding the use of other analgesic methods, such as continuous ketamine infusion, perioperative oral gabapentin, acetaminophen, continuous wound infiltration of local anesthetics, a single dose of systemic dexamethasone, and lidocaine infusion in this patient population. Moreover, appropriate combinations of analgesics have not been established. The aim of this literature review is to provide detailed information of each analgesic technique so that clinicians can make appropriate choices regarding pain management in patients with adolescent idiopathic scoliosis undergoing posterior spinal fusion.

© 2018, Springer Nature B.V. Hemodynamic monitoring is mandatory for perioperative management of cardiac surgery. Recently, the estimated continuous cardiac output (esCCO) system, which can monitor cardiac output (CO) non-invasively based on pulse wave transit time, has been developed. Patients who underwent cardiovascular surgeries with hemodynamics monitoring using arterial pressure-based CO (APCO) were eligible for this study. Hemodynamic monitoring using esCCO and APCO was initiated immediately after intensive care unit admission. CO values measured using esCCO and APCO were collected every 6 h, and stroke volume variation (SVV) data were obtained every hour while patients were mechanically ventilated. Correlation and Bland–Altman analyses were used to compare APCO and esCCO. Welch’s analysis of variance, and four-quadrant plot and polar plot analyses were performed to evaluate the effect of time course, and the trending ability. A p-value < 0.05 was considered statistically significant. Twenty-one patients were included in this study, and 143 and 146 datasets for CO and SVV measurement were analyzed. Regarding CO, the correlation analysis showed that APCO and esCCO were significantly correlated (r = 0.62), and the bias ± precision and percentage error were 0.14 ± 1.94 (L/min) and 69%, respectively. The correlation coefficient, bias ± precision, and percentage error for SVV evaluation were 0.4, − 3.79 ± 5.08, and 99%, respectively. The time course had no effects on the biases between CO and SVV. Concordance rates were 80.3 and 75.7% respectively. While CO measurement with esCCO can be a reliable monitor after cardiovascular surgeries, SVV measurement with esCCO may require further improvement.

© by the Aerospace Medical Association, Alexandria, VA. BACKGROUND: Mild hypercapnia combined with a cephalad fluid shift [e.g., that occurring during spaceflight or laparoscopic surgery with head-down tilt (HDT)] might affect cerebral autoregulation. However, no reports have described the effects of the combination on dynamic cerebral autoregulation. Therefore, we tested the hypothesis that the combination of mild hypercapnia and a cephalad fluid shift would attenuate dynamic cerebral autoregulation. METHODS: There were 15 healthy male volunteers who were exposed to 4 10-min protocols in which they received air in the supine position (Placebo/Supine), 3% carbon dioxide (CO2) in the supine position (CO2/Supine), air with 210° HDT (Placebo/ HDT) and 3% CO2 with 210° HDT (CO2/HDT). Dynamic cerebral autoregulation was evaluated using a transfer function analysis of the beat-to-beat variability in mean arterial blood pressure (ABP) and mean cerebral blood flow (CBF) velocity. RESULTS: The phase in the low-frequency range was significantly lower during CO2/HDT than all other protocols, where CO2/HDT was 225% lower than Placebo/Supine (CO2/HDT, 0.49 ± 0.21; Placebo/Supine, 0.65 ± 0.16 radians). The transfer function gain in the low-frequency range was significantly higher during CO2/HDT than all other protocols, where CO2/ HDT was 26% higher than Placebo/Supine (CO2/HDT, 1.08 ± 0.34; Placebo/Supine, 0.86 ± 0.28 cm · s-1 · mmHg-1). However, neither the CO2/Supine nor Placebo/HDT showed significant differences compared with the Placebo/Supine. DISCUSSION: Even short-term exposure to 3% CO2 plus HDT increased synchrony and the magnitude of transmission between ABP and CBF in the low-frequency range. Thus, the combination of mild hypercapnia and a cephalad fluid shift attenuated dynamic cerebral autoregulation.

© 2016 Wolters Kluwer Health, Inc. All rights reserved. Objective: Some patients experience severe chronic pain after intramedullary spinal cord tumor (IMSCT) resection, but the underlying mechanisms have yet to be fully elucidated. We aimed to investigate perioperative factors associated with chronic pain after IMSCT resection. Materials and Methods: We analyzed data from a postal survey and the medical records of patients who had undergone IMSCT resection in our institution between 2000 and 2008. Chronic pain was assessed using the Neuropathic Pain Symptom Inventory score, and its associations with factors related to tumor pathology, patient demographics, neurological findings, surgery, anesthesia, and perioperative management were determined. Results: Seventy-eight consecutive patients (55 men and 23 women; age 17 to 79 y) were included in the statistical analysis of the present study. In univariate analyses, sex, body mass index, preoperative tumor-related pain, preoperative nonsteroidal anti-inflammatory drugs, intraoperative hypotension, postoperative corticosteroids, and decrease in Japanese Orthopaedic Association (JOA) scores were found to be associated with postsurgical chronic central pain. Logistic regression analysis identified 3 significant factors: a decline in JOA scores compared with preoperative values (odds ratio [OR], 3.33; 95% confidence interval [CI], 1.18-9.42; P=0.023), intraoperative hypotension (OR, 3.01; 95% CI, 1.02-8.97; P=0.047), and postoperative corticosteroids (OR, 3.21; 95% CI, 1.02-10.09; P=0.046). Discussion: Decline in JOA score, intraoperative hypotension, and postoperative corticosteroids are independently associated with postsurgical chronic central pain. Intraoperative hypotension and the use of postoperative corticosteroids can be avoided or modified during perioperative management. As results from animal studies have indicated that the administration of corticosteroids may intensify chronic pain, further studies in larger cohorts are required to definitively determine the effect of corticosteroids on postsurgical central pain.

© 2017, Japanese Society of Anesthesiologists. Purpose: Pain is a global public health problem with implications for both personal and social heath. Fear-avoidance beliefs (FABs) have been demonstrated to negatively impact and prolong pain in many Western countries, but little is known about the association between FABs and chronic pain (CP) in Asian countries, including Japan. We examined the relationship between FABs and CP in Japanese white-collar workers, a growing population with a high prevalence of CP. Methods: Questionnaires and company records were used to gather data from 433 Japanese white-collar workers. Data were related to experience of pain, participant sociodemographic/health/lifestyle characteristics, fear-avoidance beliefs [Tampa Scale for Kinesiophobia (TSK)], work-related psychosocial factors (Brief Job Stress Questionnaire), and depressive illness [Psychological Distress Scale (K6)]. Analysis of covariance and multilevel logistic regression modeling were used to analyze associations between the data while controlling for factors known to influence CP prevalence. Results: Prevalence rate of CP was 11.1% (48 of 433 persons). Adjusted odds ratios for participants with CP significantly increased in participants with high TSK scores, even after adjusting for factors known to influence CP prevalence. Conclusion: We found a significant association between high TSK scores and CP in Japanese white-collar workers when controlling for other known factors that influence CP such as work-related psychosocial characteristics and depressive conditions. This finding suggests that FABs are independently associated with prevalence of CP.

© 2016, Springer International Publishing. Objective: We tested the hypothesis that deep anesthesia with sevoflurane, known as a potent immunomodulator, for 4 h would worsen the 24-h outcomes of rats through modulation of the inflammatory responses. Methods: Forty-nine male Wistar rats, administered low dose of lipopolysaccharide (0.5 mg/kg) intravenously to elicit moderate inflammatory responses mimicked mild surgical stress, underwent one minimum alveolar concentration (MAC) or 2 MAC sevoflurane anesthesia for 4 h. The 24-h survival rate, arterial blood gases, plasma interleukin (IL)-6 and tumor necrosis factor (TNF)-α concentrations, and rate of T lymphocyte apoptosis in spleen were evaluated. We further examined the effects of hypotension and TNF-α discharge on the survival rate. Results: The survival rate in 2 MAC group was significantly lower accompanied with decreased base excess and increased level of cytokines (IL-6, TNF-α) compared to 1 MAC group. The apoptosis rate did not differ between the two groups. Neither norepinephrine infusion to restore hypotension nor administration of anti-TNF-α antibody improved the outcome in the 2 MAC group. Conclusions: Deep anesthesia with sevoflurane even for a short-term period augments the release of inflammatory cytokines evoked by inflammatory insults like surgical stress, impairs the acid–base balance, and subsequently deteriorates the outcomes.

© 2016 Australian College of Critical Care Nurses Ltd Introduction In critically ill patients, excessive bed rest and immobilisation have been shown to cause disuse muscle atrophy, which contributes to prolonged hospitalisation and decreased activity of daily living (ADL) levels. However, the degree and site specificity of acute disuse muscle atrophy in critically ill patients during a relatively short intensive care unit (ICU) stay have not been fully elucidated. Methods Critically ill patients, who required bed rest on ICU admission, were eligible for this study. The degree of skeletal muscle atrophy was evaluated on the day of, and 72 and 144 h after ICU admission by measuring the limb circumference in ADL-dependent or -independent patients separately at five different sites: the midpoint of the upper limb between the acromion and the olecranon, the maximum diameter of the triceps surae in the lower leg, and three different sites in the thigh at 5, 10, and 15 cm above the superior pole of the patella. Value of the limb circumference was presented as a percentage relative to the baseline (median). Results In ADL-dependent patients, limb circumferences at all five sites were decreased significantly at 144 h compared with the baseline (98.9–100% in the upper limbs, 97.1–97.2% in the lower legs, and 96.5–99.1% in the thighs), but not at 72 h. In contrast, the limb circumferences at almost all sites decreased significantly at both 72 and 144 h (100% in the upper limbs, 94.5–94.7% in the lower legs, and 89.7–94.7% in the thighs), compared with the baseline in ADL-independent patients. Muscle atrophy was greater at the four different lower-limb sites compared to the upper limb during 144 h in the ICU in the ADL-independent, but not in the ADL-dependent patients. Conclusions Compared to ADL-dependent patients, ADL-independent patients are prone to develop muscle weakness, especially in the lower limbs.

© 2015, The Japanese Association for Thoracic Surgery. A 60-year-old man received mitral valve repair via right mini-thoracotomy, which was followed by unilateral re-expansion pulmonary edema on the right side and severe hemoptysis just after the surgery. Despite differential lung ventilation with unilateral high positive end expiratory pressure was initiated for the affected right lung, respiratory function did not improved and hemodynamics was collapsed in the next day. Veno-venous extracorporeal membrane oxygenation was initiated by cannulation of the right jugular and the left femoral vein. After pulmonary function recovered gradually, veno-venous extracorporeal membrane oxygenation was terminated on the fifth postoperative day. He was discharged in ambulatory condition on postoperative day 52.

© 2019, The Author(s). Dexamethasone is widely used for postoperative nausea and vomiting (PONV) prophylaxis, but its effect on PONV prevention in paediatric patients is validated only in short minor surgical procedures. In this study, we aimed to determine whether a single dose of dexamethasone reduces PONV in highly invasive surgeries that require opioid-based postoperative analgesia. One hundred adolescents undergoing scoliosis correction surgery were randomized to receive intravenous dexamethasone 0.15 mg/kg (dexamethasone group) or saline (control group) at induction of anaesthesia. The primary outcome was the incidence of PONV in the 72 h postoperatively. Data for 98 patients were available for analysis. The 72-h incidence of PONV was significantly lower in the dexamethasone group than in the control group (62.5% vs 84.0%; RR 0.74, 95% CI 0.58–0.96, P = 0.02). During the first and second 24-h postoperative intervals, fewer patients in the dexamethasone group received rescue antiemetics. Visual analogue scale scores for nausea and pain were lower in the dexamethasone group than in the control group during the first 24 h postoperatively. Dexamethasone did not increase the number of adverse events. The results of this study showed that a single dose of dexamethasone was effective for reducing PONV after paediatric scoliosis correction surgery.

© 2018, Japanese Society of Anesthesiologists. Background: Both anesthetic-induced and ischemic preconditioning are protective against hepatic ischemia–reperfusion injury. However, the effects of these preventive methods on the metabolic function remain to be elucidated. We investigated the anesthetic conditioning and ischemic preconditioning on the metabolic function of the rabbit model of hepatic ischemia–reperfusion. Methods: After approval by the institutional animal care and use committee, 36 Japanese White rabbits underwent partial hepatic ischemia for 90 min either under sevoflurane or propofol anesthesia. All the rabbits underwent 90 min of hepatic ischemia, and half of the rabbits in each group underwent additional 10-min ischemia and 10-min reperfusion before index ischemia. Hepatic microvascular blood flow was intermittently measured during reperfusion period, and galactose clearance, serum aminotransferase activities, and lactate concentrations were determined 180 min after reperfusion. Results: Neither anesthetic conditioning with sevoflurane nor ischemic preconditioning altered hepatic microvascular blood flow during reperfusion and serum transaminase activities after reperfusion. However, galactose clearance of reperfused liver was significantly higher under sevoflurane anesthesia than propofol (0.016 ± 0.005/min vs. 0.011 ± 0.004/min). Statistically significant interaction between anesthetic choice and application of ischemic preconditioning suggests that the ischemic preconditioning is selectively protective under propofol anesthesia. Increase of blood lactate concentration was significantly suppressed under sevoflurane anesthesia compared to propofol (1.5 ± 0.8 vs. 3.9 ± 1.4 mmol/l) without any statistically significant interaction with the application of ischemic preconditioning. Conclusion: Sevoflurane attenuated the decrease of galactose clearance and increase of the blood lactate after reperfusion compared to propofol. Application of ischemic preconditioning was significantly protective under propofol anesthesia.

© by the Aerospace Medical Association, Alexandria, VA. BACKGROUND: Exposure to carbon dioxide (CO2) and cephalad fluid shift are considered factors that affect intracranial pressure (ICP) during spaceflight. Increases in ICP were reported during cephalad fluid shift induced by head-down tilt (HDT), while little is known regarding the effect of additional CO2during HDT on ICP. Therefore, we tested the hypothesis that this combination increases ICP more than HDT alone. METHODS: There were 15 healthy male volunteers who underwent 4 types of 10-min interventions consisting of Placebo/Supine (air and supine), CO2/Supine (3% CO2and supine, CO2alone), Placebo/HDT (air and 210° HDT, HDT alone), and CO2/HDT (3% CO2and 210° HDT, combination). Using arterial blood pressure (ABP) and cerebral blood flow velocity waveforms, ICP was estimated noninvasively before and during the four interventions. Two calculation methods were employed. One is based on the signal transformation from ABP to ICP with the intracranial component as a "black box" system (nICP_BB), and the other is based on the equation ICP = ABP 2 cerebral perfusion pressure, reflecting critical closing pressure (nICP_CrCP). RESULTS: Both nICP_BB and nICP_CrCP significantly increased during Placebo/HDT and CO2/HDT, although there was no statistically significant difference between the nICP indexes of these two interventions. DISCUSSION: Increases in ICP were observed during both Placebo/HDT and CO2/HDT. Contrary to our hypothesis, the combination of 3% CO2and 210° HDT did not increase ICP remarkably compared to 210° HDT alone. Therefore, the addition of 3% CO2is considered to have little effect on increasing ICP during cephalad fluid shift.

© 2019 The Author(s). Background: In the Berlin definition, acute respiratory distress syndrome (ARDS) is stratified into three stages according to oxygenation severity at the onset. The relevance between ARDS severity and prognosis varies among published reports and has not been verified, especially in Asian patients. Methods: In this study, we examined the associations between the Berlin definition criteria and prognosis and clinical parameters, including high-resolution computed tomography (HRCT) scores of fibroproliferative changes of the lungs. One hundred fifty-three patients (45 females; mean age, 67 y/o), who met the Berlin definition and received treatment in our intensive care unit between January 2012 and December 2015, were enrolled. Results: The severity of ARDS was mild in 42 patients, moderate in 71, and severe in 40. The underlying diseases included pneumonia in 56 patients and aspiration in 43. Forty-two (27.5%) patients were deceased within 30 days, and the 30-day mortality was 10% in mild ARDS, 23% in moderate, and 55% in severe, which were significantly different (P < 0.05). In the non-survivors, APACHE II, SOFA, and SAPS II scores were higher than in the survivors (P < 0.001). Multivariate analyses revealed that elevated blood lactate level (≥ 2.0 mmol/L) and increased HRCT scores were significantly associated with weaning failure and 30-day mortality of the patients with ARDS. Conclusions: These results suggested that the severity criteria in the Berlin definition might be associated with the prognosis of the patients. Blood lactate levels and HRCT score might be predictive of the outcome of patients with ARDS.

A 50-year-old man with type 2 diabetes mellitus was scheduled for laparoscopic partial liver resection. Six months prior to the surgery, he developed frequent hypoglycemic attacks and was diagnosed as anti-insulin antibody positive. The operation was performed under general anesthesia with epidural anesthesia Intermittent and continuous insulin administration was required during liver resection due to persistent hyperglycemia After termination of the liver resection, the patient exhibited uncontrolled hypo- and hyperglycemia and recovery from anesthesia was delayed due to severe hypoglycemia He recovered immediately after 40% glucose administration. However, frequent glucose administration was required for two hours after transfer to the ICU due to hypoglycemia It should be born in mind that preoperative poor glucose control might be caused by anti-insulin antibodies and lead to difficult perioperative glucose management.

© 2018 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved. Objectives: To compare physicians' perceptions and practice of end-of-life care in the ICU in three East Asian countries cultures similarly rooted in Confucianism. Design: A structured and scenario-based survey of physicians who managed ICU patients from May 2012 to December 2012. Setting: ICUs in China, Korea, and Japan. Subjects: Specialists who are either intensivists or nonintensivist primary attending physicians in charge of patients (195 in China, 186 in Korea, 224 in Japan). Interventions: None. Measurements and Main Results: Country was independently associated with differences in the practice of limiting multiple forms of life-sustaining treatments on multivariable generalized linear model analysis. Chinese respondents were least likely to apply do-not-resuscitate orders, even if they existed (p < 0.001). Japanese respondents were most likely to practice do not resuscitate for terminally ill patients during cardiac arrest, even when no such prior order existed (p < 0.001). Korean respondents' attitudes were in between those of Chinese and Japanese respondents as far as withdrawing total parenteral nutrition, antibiotics, dialysis, and suctioning was concerned. Chinese respondents were most uncomfortable discussing end-of-life care issues with patients, while Japanese respondents were least uncomfortable (p < 0.001). Chinese respondents were more likely to consider financial burden when deciding on limiting life-sustaining treatment (p < 0.001). Japanese respondents felt least exposed to personal legal risks when limiting life-sustaining treatment (p < 0.001), and the Korean respondents most wanted legislation to guide this issue (p < 0.001). The respondents' gender, religion, clinical experience, and primary specialty were also independently associated with the different perceptions of end-of-life care. Conclusions: Despite similarities in cultures and a common emphasis on the role of family, differences exist in physician perceptions and practices of end-of-life ICU care in China, Korea, and Japan. These findings may be due to differences in the degree of Westernization, national healthcare systems, economic status, and legal climate.

© 2019 Yuta Suzuki et al. Background. Tracheostomy is a necessary procedure for patients who require long-term mechanical ventilation support. There are two methods for tracheostomy in current use: surgical tracheostomy (ST) and percutaneous dilational tracheostomy (PDT). In the current study, we retrospectively compared the safety of both procedures performed in our intensive care unit (ICU). Methods. In this study, we enrolled subjects who underwent tracheostomy in our ICU between January 2012 and March 2016. We excluded subjects who were <20 years old and underwent tracheostomy in the operating room. As a primary outcome, we evaluated the rate of complications between ST and PDT groups. The length of ICU stay, time to tracheostomy from intubation, and the rate of mechanical ventilation and mortality at 28 postoperative days were also examined as secondary outcomes. Results. Compared with the ST group, the rate of all complications was lower in the PDT group (13.4% vs. 38.8%, p=0.007). Although the rate of intraoperative complications did not differ between the two groups (3.8% vs. 8.1%, p=0.62), relative to the ST procedure, the PDT procedure was associated with fewer postoperative complications (34.6% vs. 9.6%, p=0.003). Among postoperative complications, accidental removal of the tracheostomy tube and an air leak from the tracheostomy fistula were less frequent in the PDT group than the ST group. Between the two groups, there were no significant differences in their secondary outcomes. Conclusion. This retrospective study indicates that relative to ST, PDT is a safer procedure to be performed in the ICU. Fewer postoperative complications following PDT might be attributed to the small skin incision made during this procedure.

© 2016, Japanese Circulation Society. All Rights Reserved. Background: Hydrogen gas inhalation (HI) ameliorates cerebral and cardiac dysfunction in animal models of postcardiac arrest syndrome (PCAS). HI for human patients with PCAS has never been studied. Methods and Results: Between January 2014 and January 2015, 21 of 107 patients with out-of-hospital cardiac arrest achieved spontaneous return of circulation. After excluding 16 patients with specific criteria, 5 patients underwent HI together with target temperature management (TTM). No undesirable effects attributable to HI were observed and 4 patients survived 90 days with a favorable neurological outcome. Conclusions: HI in combination with TTM is a feasible therapy for patients with PCAS.

© 2019 The Author(s). Lipocalin-2 (Lcn2), an innate immune protein, has come to be recognized for its roles in iron homeostasis, infection, and inflammation. In this narrative review, we provide a comprehensive description based on currently available evidence of the clinical implications of Lcn2 and its therapeutic potency in gut-origin sepsis. Lcn2 appears to mitigate gut barrier injury via maintaining homeostasis of the microbiota and exerting antioxidant strategy, as well as by deactivating macrophages and inducing immune cell apoptosis to terminate systemic hyper-inflammation. We propose that development of a therapeutic strategy targeting lipocalin-2 could be highly promising in the management of gut-origin sepsis.