Okayama University Medical SchoolActa Medica Okayama0386-300X6862014Mean Lung Pressure during Adult High-Frequency Oscillatory Ventilation: An Experimental Study Using a Lung Model323329ENTakahiroHirayamaOsamuNaganoNaokiShibaTetsuyaYumotoKeijiSatoMichihisaTeradoToyomuUgawaShingoIchibaYoshihitoUjikeOriginal Article/10.18926/AMO/53021In adult high-frequency oscillatory ventilation (HFOV), stroke volume (SV) and mean lung pressure (PLung) are important for lung protection. We measured the airway pressure at the Y-piece and the lung pressure during HFOV using a lung model and HFOV ventilators for adults (R100 and 3100B). The lung model was made of a 20-liter, airtight rigid plastic container (adiabatic compliance:
19.3ml/cmH<sub>2</sub>O) with or without a resistor (20cmH<sub>2</sub>O/l/sec). The ventilator settings were as follows:
mean airway pressure (MAP), 30cmH2O;frequency, 5-15Hz (every 1Hz);airway pressure amplitude (AMP), maximum;and % of inspiratory time (IT), 50% for R100, 33% or 50% for 3100B. The measurements were also performed with an AMP of 2/3 or 1/3 maximum at 5, 10 and 15Hz. The PLung and the measured MAP were not consistently identical to the setting MAP in either ventilator, and decreasing IT decreased the PLung in 3100B. In conclusion, we must pay attention to the possible discrepancy between the PLung and the setting MAP during adult HFOV.No potential conflict of interest relevant to this article was reported.Okayama University Medical SchoolActa Medica Okayama0386-300X6852014A New Classification System for Evaluating Patients with Severe Trauma Using B-type Natriuretic Peptide Levels and Estimated Glomerular Filtration Rate285290ENSunaoMorisadaToyomuUgawaNobuyukiNosakaYoshihitoUjikeOriginal Article10.18926/AMO/52897Current systems for the evaluation of trauma severity are tedious and difficult to apply in an actual emergency setting. We aimed to develop and assess the accuracy of a more efficient severity evaluation system, termed the Ugawa classification, using brain-type natriuretic peptide (BNP) measurement and the estimated glomerular filtration rate (eGFR). Two-hundred trauma patients were divided into 2 groups using an eGFR cut-off value of 90ml/min/1.73m2 as an indicator of normal renal function and 2 additional groups according to whether the BNP values were greater or less than the age in years. This resulted in 4 subject groups with different combinations of eGFR and BNP. The mean SOFA score, injury severity scores (ISS), trauma and injury severity scores (TRISS), and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores of the groups were compared by Kruskal-Wallis test, and the mortality rate after 90 days was calculated. Significant intergroup differences were found in SOFA scores, ISS scores, and APACHE II-predicted mortality rates. Although no significant differences were found in the mortality rate after 90 days or TRISS-predicted mortality rate among the 4 groups, there was a trend toward increasing trauma severity from group 1 to 4. Thus, the Ugawa classification is as accurate as existing systems, has greater efficiency, and is user-friendly.No potential conflict of interest relevant to this article was reported.Okayama University Medical SchoolActa Medica Okayama0386-300X6662012Evaluating the Need for and Effect of Percutaneous Transluminal Angioplasty on Arteriovenous Fistulas by Using Total Recirculation Rate per Dialysis Session (gClearance Gaph)443447ENToyomuUgawaKazufumiSakuramaTakashiYorifujiMunenoriTakaokaYasuhiroFujiwaraNarutoshiKabashimaDaisukeAzumaTakahiroHirayamaKoheiTsukaharaSunaoMorisadaAtsuyoshiIidaKeitaroTadaNaokiShibaNobuoSatoShingoIchibaKoichiKinoMasakiFukushimaYoshihitoUjikeOriginal Article/10.18926/AMO/49040The functioning of an arteriovenous fistula (AVF) used for vascular access during hemodialysis has been assessed mainly by dilution methods. Although these techniques indicate the immediate recirculation rate, the results obtained may not correlate with Kt/V. In contrast, the clearance gap (CL-Gap) method provides the total recirculation rate per dialysis session and correlates well with Kt/V. We assessed the correlation between Kt/V and CL-Gap as well as the change in radial artery (RA) blood flow speed in the fistula before percutaneous transluminal angioplasty (PTA) in 45 patients undergoing continuous hemodialysis. The dialysis dose during the determination of CL-Gap was 1.2 to 1.4 Kt/V. Patients with a 10% elevation or more than a 10% relative increase in CL-Gap underwent PTA (n45), and the values obtained for Kt/V and CL-Gap before PTA were compared with those obtained immediately afterward. The mean RA blood flow speed improved significantly (from 52.9 to 97.5cm/sec) after PTA, as did Kt/V (1.07 to 1.30) and CL-Gap (14.1% to |0.2%). A significant correlation between these differences was apparent (r|0.436 and p0.003). These findings suggest that calculating CL-Gap may be useful for determining when PTA is required and for assessing the effectiveness of PTA, toward obtaining better dialysis.No potential conflict of interest relevant to this article was reported.Okayama University Medical SchoolActa Medica Okayama0386-300X6642012Humidification of Base Flow Gas during Adult High-Frequency Oscillatory Ventilation:An Experimental Study Using a Lung Model335341ENNaokiShibaOsamuNaganoTakahiroHirayamaShingoIchibaYoshihitoUjikeOriginal Article10.18926/AMO/48688In adult high-frequency oscillatory ventilation (HFOV) with an R100 artificial ventilator, exhaled gas from patientʼs lung may warm the temperature probe and thereby disturb the humidification of base flow (BF) gas. We measured the humidity of BF gas during HFOV with frequencies of 6, 8 and 10Hz, maximum stroke volumes (SV) of 285, 205, and 160ml at the respective frequencies, and, BFs of 20, 30, 40l/min using an original lung model. The R100 device was equipped with a heated humidifier, HummaxU, consisting of a porous hollow fiber in circuit. A 50-cm length of circuit was added between temperature probe (located at 50cm proximal from Y-piece) and the hollow fiber. The lung model was made of a plastic container and a circuit equipped with another HummaxU. The lung model temperature was controlled at 37. The HummaxU of the R100 was inactivated in study-1 and was set at 35 or 37 in study-2. The humidity was measured at the distal end of the added circuit in study-1 and at the proximal end in study-2. In study-1, humidity was detected at 6Hz (SV 285ml) and BF 20l/min, indicating the direct reach of the exhaled gas from the lung model to the temperature probe. In study-2 the absolute humidity of the BF gas decreased by increasing SV and by increasing BF and it was low with setting of 35. In this study setting, increasing the SV induced significant reduction of humidification of the BF gas during HFOV with R100.No potential conflict of interest relevant to this article was reported.Okayama University Medical SchoolActa Medica Okayama0386-300X6562011Successful Extracorporeal Life Support for Life-threatening Hypercapnia with Bronchiolitis Obliterans after Allogeneic Hematopoietic Stem Cell Transplantation403406ENKoichiWasedaYasushiTanimotoShingoIchibaNobuakiMiyaharaToshiMurakamiNobuakiOchiMichihisaTeradoOsamuNaganoYoshinobuMaedaArihikoKanehiroYoshihitoUjikeMitsuneTanimotoCase Report/10.18926/AMO/47266Bronchiolitis obliterans (BO) is a disease with a poor prognosis, and a key factor that limits long-term survival after allogeneic hematopoietic stem cell transplantation (HSCT). We here report a case of a 31-year woman with acute lymphatic leukemia, which was treated by chemotherapy and HSCT, and consequently developed BO 2 years after HSCT. A non-tuberculous mycobacterial infection occurred and showed gradual exacerbation. She started taking anti-mycobacterial drugs, but lost appetite, felt tired and finally lost consciousness one month after beginning medication. Arterial blood gas revealed marked hypercapnia. Using extracorporeal life support (ECLS), the carbon dioxide concentration was reduced and her consciousness recovered. To our knowledge, this is the first case in which ECLS was successfully used for hypercapnia in a patient with BO.No potential conflict of interest relevant to this article was reported.ͺRγwοActa Medica Okayama0030-155812332011V^CtGUECXiA/H1N1j΄υγΙARDS𽡽1α221225ENAkihikoTaniguchiNobuakiMiyaharaAtsushiNakaharaSaburoTakataRyoSakugawaOsamuNaganoYasushiTanimotoArihikoKanehiroKatsuyukiKiuraYoshitoUjikeMitsuneTanimotoA 28-year-old man with a history of mental retardation was admitted to our hospital because of dyspnea, cough and high fever. His SpO(2) level at room-environmental conditions was in the eighties, and his chest radiograph showed diffuse infiltrates in both lungs. He was diagnosed as suffering from influenza A by a rapid influenza virus antigen test. The echocardiogram showed no evidence of left cardiac failure; therefore, his symptoms were consistent with acute respiratory distress syndrome (ARDS). Oseltamivir was started, and antibiotics were also given because of the possibility of secondary bacterial infection. Due to respiratory failure and low blood pressure, which suggested septic shock, intensive treatments including mechanical ventilation were performed. Corticosteroid therapy was started for ARDS and sepsis, and these therapies improved his respiratory condition. Polymerase chain reaction of his pharyngeal swab revealed that he had influenza A (H1N1). This is the first case of ARDS following infection by influenza A (H1N1) virus in Japan.No potential conflict of interest relevant to this article was reported.Okayama University Medical SchoolActa Medica Okayama0386-300X5922005Out-of hospital cardiac arrest in Okayama city (Japan): outcome report according to the "Utstein Style".4954ENHoeiHayashiYoshihitoUjikeArticle/10.18926/AMO/31965<p>The purpose of this study was to evaluate the outcomes for out-of-hospital cardiac arrest (OHCA) and cardiopulmonary resuscitation (CPR) in the city of Okayama, Japan, during a 1-year period after the reorganization of defibrillation by Emergency Life-Saving Technicians (ELSTs) with standing orders of CPR. The data were collected prospectively according to an Utstein style between June 1, 2003 and May 31, 2004; OHCA was confirmed in 363 patients. Cardiac arrest of presumed cardiac etiology (179) was witnessed by a bystander in 62 (34.6%) cases. Of this group, ventricular fibrillation (VF) was documented in 20 cases (32.3%), and 1 patient (5%) was discharged alive without severe neurological disability. This outcome is average in Japan, but it is quite low level compared with Western countries because there is less VF in Japan. The Utstein style revealed that we must try to detect VF before the rhythm changes and to provide defibrillation as soon as possible in order to improve outcomes. Further research will be required to accurately evaluate OHCA in Okayama city.</p>
No potential conflict of interest relevant to this article was reported.Okayama University Medical SchoolActa Medica Okayama0386-300X6222008Effect of pentoxifylline on diaphragmatic contractility in septic rats.101107ENWataruDanjoNaoyukiFujimuraYoshihitoUjikeOriginal Article/10.18926/AMO/30964<p>We investigated the effects of pentoxifylline (PTX) on endotoxin-induced diaphragmatic dysfunction in vitro. Seventy-two rats were divided into 3 groups: a group in which endotoxin (20 mg/kg) was injected intraperitoneally (endotoxin-group), a group in which PTX (100 mg/kg) was injected intraperitoneally 30 min before injection of endotoxin (endotoxin-PTX group), and a group in which only saline was given (sham group). Left hemidiaphragms were removed 4 h after injection of endotoxin. We evaluated the diaphragmatic contractility by twitch characteristics and force-frequency curves in vitro. We measured serum TNF-alpha concentrations, diaphragm malondialdehyde (MDA) levels (an index of oxygen-derived free radical-mediated lipid peroxidation), and diaphragm cAMP concentrations. Diaphragmatic force generation capacity was signifi cantly reduced after injection of endotoxin. Serum TNF-alpha concentrations and diaphragmatic MDA levels were significantly elevated after injection of endotoxin. PTX administration significantly improved diaphragmatic contractility and prevented the elevation in TNF-alpha concentrations and MDA levels after injection of endotoxin. There were no significant changes in the diaphragm cAMP concentrations among the 3 groups. These results demonstrated that PTX administration prevented endotoxin-induced diaphragmatic dysfunction without changing diaphragm muscle cAMP concentrations. The protective effects of PTX against endotoxininduced diaphragmatic contractile deterioration might be caused by attenuating TNF-alpha-mediated oxygen-derived free radical production.</p>No potential conflict of interest relevant to this article was reported.Okayama University Medical SchoolActa Medica Okayama0386-300X6222008Evaluation of pressure support ventilation with seven different ventilators using Active Servo Lung 5000127133ENMichihisaTeradoShingoIchibaOsamuNaganoYoshihitoUjikeOriginal Article/10.18926/AMO/30963<p>In modern emergency and critical care, physicians tend to choose the mode of mechanical ventilation based on spontaneous breathing for the purpose of promoting discharge of pulmonary secretion and preventing atelectasis in patients with acute respiratory insufficiency. However, we often observe "differences in recovery" among patients treated using the same PSV settings beyond "differences in individual characteristics." We evaluated the Pressure Support Ventilation (PSV) mode aiming to certify the difference among 7 representative mechanical ventilators using the Active Servo Lung 5000 (ASL5000) respiratory simulation system. The following parameters were measured: The time delay that resulted in the lowest inspiratory pressure from the point at which the ventilator recognized spontaneous breathing (TD), the lowest inspiratory airway pressure (cmH2O) generated prior to the initiation of PSV (DeltaPaw), the work of breathing while triggering required to achieve the lowest inspiratory negative pressure from the beginning of inspiratory support (WOBtrig), and the inspiratory work of breathing (WOBi). The mean TD of the Puritan-Bennett type 840 (PB840) was signifi cantly shorter than those of other ventilators (p0.01). The WOBtrig of the PB840 was significantly lower than those of others (p0.01). However, the WOBi values of the Servo-I and T-Bird were greater than the others, with the Evita series showing the smallest WOBi of the 7 ventilators tested. According to this simulation study using ASL 5000, we concluded that PB840 was the most rapid response ventilator, but the Evita series was the gentlest mechanical ventilator among 7 ventilators from the standpoint of the total work of breathing during the inspiration phase in the setting of PSV.</p>No potential conflict of interest relevant to this article was reported.Okayama University Medical SchoolActa Medica Okayama0386-300X6242008Experimental Study of a Novel Method of Cardiopulmonary Resuscitation Using a Combination of Percutaneous Cardiopulmonary Support and Liposome-encapsulated Hemoglobin (TRM645)235239ENKeiOtaToshihideMizunoEisukeTatsumiNobumasaKatagiriYoshiyukiTaenakaTakanobuIshizukaYoshitakaOgataYoshihitoUjikeOriginal Article/10.18926/AMO/30941<p>Percutaneous cardiopulmonary support (PCPS) has been applied for cardiopulmonary arrest (CPA). We have developed a novel method of cardiopulmonary resuscitation using PCPS combined with liposome-encapsulated hemoglobin (TRM645) to improve oxygen delivery to vital organs. Ventricular fibrillation was electrically induced to an adult goat for 10 min. Next, PCPS (30 ml/kg/min, V/Q: 1) was performed for 20 min. Then, external defibrillation was attempted and observed for 120 min. The TRM group (n5) was filled with 300 mL of TRM645 for the PCPS circuit. The control group (n5) was filled with the same volume of saline. The delivery of oxygen (DO2) and oxygen consumption (VO2) decreased markedly by PCPS after CPA, compared to the preoperative values. DO2 was kept at a constant level during PCPS in both groups, but VO2 slowly decreased at 5, 10, and 15 min of PCPS in the control groups, demonstrating that systemic oxygen metabolism decreased with time. In contrast, the decreases in VO2 were small in the TRM group at 5, 10, and 15 min of PCPS, demonstrating that TRM645 continuously maintained systemic oxygen consumption even at a low flow rate. AST and LDH in the TRM group were lower than the control. There were significant differences at 120 min after the restoration of spontaneous circulation (p<0.05).</p>No potential conflict of interest relevant to this article was reported.ͺRγwοActa Medica Okayama0030-155811412002 ηΚΔzΗΖARDSΜ‘ΓνͺγΜΣ`518ENNo potential conflict of interest relevant to this article was reported.ͺRγwοActa Medica Okayama0030-155811712005dΗΉOγx^αΙΞ΅xtΨpπ{s΅~½Ε«½Pα4750ENMichioInukaiShingoIchibaMikakoTsudaNaoyukiFujimuraYoshihitoUjikeSyujiIchiharaMotoiAoiYoshifumiSanoHiroshiDateNobuyoshiShimizuThoracic trauma is rarely managed by major thoracotomy. We report a 61-year-old male patient with pulmonaryabscess after severe thoracic trauma, who was managed successfully by major thoracotomy. The patient was injured after a fall from a height of 6 meters.He developed multiple rib fractures with right flail chest, pulmonary contusion,right hemo-pneumothorax, and subcutaneous emphysema.He was intubated and ventilated, and his chest was drainaged. He had been managed with conservative treatment initially. However he developed a pulmonary
abscess in the right lung that was unresponsive to CT-guided drainage therapy. The right lower lobectomy was performed on the 23rd day after his injury. His general condition greatly recovered and all the chest drains were removed on the 45th post trauma day. He was discharged from the hospital on the 86th post operative day. He was
considered now fully recovered at 7 months after the accident.No potential conflict of interest relevant to this article was reported.