Satoshi Ohki

Accuracy and repeatability of blood volume measurement by pulse dye densitometry compared to the conventional method using 51Cr-labeled red blood cells

AbstractObjective: To determine the accuracy and repeatability of pulse dye densitometry (PDD) in measuring blood volume (BV) by comparing it with the conventional method using 51Cr-labeled red blood cells (RI method) and by assessing sequential measurements. Design: Prospective clinical study. Setting: University hospital. Patientsandparticipants: Eleven adult ICU patients who received cardiac surgery (1st ICU day). Interventions: None. Measurementsandresults: After injecting indocyanine green (10 or 20 mg) into the right atrium, its arterial concentration was continuously monitored at the nose and finger by PDD, and BV was calculated by back extrapolating the logarithmic dye concentration on the dye elimination curve between 2.5 and 5.5 min after mean transit time to each mean transit time with the least squares method. These measurements were repeated in eight patients and performed only once in the other three, and the BV was measured concurrently by the RI method one time. The Bland-Altman method was used for evaluating differences between methods and within methods. The (percentage) biases and standard deviations between the PDD and RI methods and between the successive measurements by PDD at the finger and nose were 0.26±0.49 l (8.8±15.3%) and 0.004±0.25 l (0.06±5.9%) with the probe on a nostril, and 0.16±0.56 l (2.5±14.4%) and 0.19±0.31 l (4.7±7.3%) using the finger probe. The bias between methods was less than 10%, and the repeatability of PDD was better. Conclusions: As PDD can measure BV with good repeatability and with a small bias compared to the RI method, serial changes in BV can be evaluated at the bedside of critically ill patients noninvasively and repeatedly.

A highly selective inhibitor of rho-associated coiled-coil forming protein kinase, Y-27632. Prolongs cardiac allograft survival of the BALB/c-to-c3H/He mouse model

BACKGROUND Current studies provide evidence that a small G protein, RhoAp21, and its target protein, Rho-associated coiled-coil forming protein kinase (ROCK), regulate not only cell shape but also cell migration. However, contribution of Rho/ROCK signaling to graft rejection is unknown. The purpose of this study was to evaluate the inhibitory effect of Y-27632, a highly selective ROCK inhibitor, on rejection of heterotopic cardiac transplantation in mice. METHODS BALB/c (H-2(d)) hearts were transplanted into C3H/He (H-2(k)) as allografts that were full histoincompatibility combinations. The recipients received several doses of Y-27632, commencing 1 day before cardiac transplantation until rejection. We used immunohistochemical study to detect the expression of myocardial intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), and we immunoenzymatically measured serum interleukin (IL)-6. Furthermore, we evaluated cardiac allograft vasculopathy treated with either FK506 or Y-27632 at Day 100. RESULTS The Y-27632-treated (2 mg/kg/day) allografts prolonged the mean survival time (49.6 +/- 10.1 days, n = 12) as compared with the untreated allografts (8.1 +/- 0.4 days, n = 7, p < 0.001). Histologic examinations of the Y-27632-treated allografts at Day 7 showed greatly reduced leukocyte infiltration compared with the untreated allografts. The Y-27632-treated allografts revealed faint expression of myocardial ICAM-1 and VCAM-1 at Day 7. The serum IL-6 levels also decreased in the Y-27632-treated mice. In the long-surviving Y-27632-treated allografts at Day 100, we saw neither active rejection nor apparent thickening of vascular intima. CONCLUSION Our results suggest that ROCK plays a major role in cardiac rejection in the BALB/c-to-C3H/He mouse model. Inhibition of this Rho/ROCK signaling may be an alternative therapeutic option for managing acute and chronic rejection.

Changes in diastolic regional stiffness of the left ventricle before and after coronary artery bypass grafting

SummaryTo evaluate the effect of coronary artery bypass grafting (CABG) on regional diastolic function of the left ventricular wall, we applied the concept of the stiffness constant to the diastolic σ-ln (1/H) relation, where σ is the mean wall stress, and H is the wall thickness of the region of concern, and ln (1/H) is the natural logarithm of the reciprocal of wall thickness. We assessed 12 cardiac regions in six patients with coronary artery disease who underwent CABG at the Cardiovascular Hospital of Central Japan between May 1994 and January 1995. Left ventricular pressure and regional wall thickness were measured simultaneously, with a micromanometer-tipped catheter and by twodimensional echocardiography, respectively, before and after CABG. The stiffness constant (K) was obtained by fitting the diastolic σ-ln (1/H) data points to an exponential curve with zero asymptote: σ = Cexp[Kln (1/H)]. Preoperatively, the stiffness constant in the affected region (CABG region) was greater than that in the unaffected region (non-CABG region) (4.79 ± 2.56 vs 2.95 ± 0.72). Postoperatively, the stiffness constant in the CABG region was significantly decreased, to 3.21 ± 1.22. The stiffness constant, which is derived from the σ-ln (1/H) relation, is useful for the assessment of LV regional diastolic function.

Aortic Valve Replacement for Aortic Regurgitation in a Patient With Left Ventricular Noncompaction

We present a case of a 61-year-old man who underwent aortic valve replacement for aortic regurgitation complicated with left ventricular noncompaction. The pathogenesis of this condition remains unknown. In advanced form, left ventricular noncompaction produces marked disability and carries a poor prognosis. We underscore that familiarity with this disease entity will help to stimulate early diagnosis and timely treatment when necessary.

Accuracy of carboxyhe-moglobin dilution method for the measurement of circulating blood volume

Purpose: The management of circulating blood volume (BVc) is crucial in intensive care unit (ICU) patients. The purpose of this study was to verify the accuracy and precision of the carbon monoxide-labeled hemoglobin (CO-Hb) dilution method (CO method) by comparing it with the51Cr-labeled erythrocyte dilution method (51Cr method) for the measurement of BVc.Methods: A prospective study was performed in 18 patients who underwent coronary artery bypass grafting (CABG) under mild hypothermic cardiopulmonary bypass (CPB). The BVc was measured by both the CO method and the51Cr method at 24 hr after ICU admission in order to verify the accuracy and precision of the CO method. Paired data were assessed in absolute terms, and percentage errors were calculated by the degree of agreement.Results: Small mean differences and standard deviations between the CO method and the51Cr method (−70.2±184.8 mL) and small percentage errors (−0.49±1.29%) indicated the accuracy and precision of the CO method, and a close correlation was observed (r=0.97).Conclusion: The CO method can measure BVc with a similar degree of accuracy as the51Cr method. It is simple, repeatable and safe without the risk of exposure to radioactivity in the ICU.RésuméObjectif: La gestion du volume du sang circulant (VSc) est cruciale chez les patients des unités de soins intensifs (USI). Nous avons voulu vérfier, pour la détermination du VSc, la justesse et la précision de la méthode de dilution avec oxyde de carbone et hémoglobine marquée (méthode CO) en la comparant à la méthode avec des hématies marquées par le51Cr (méthode51Cr)Méthode: Une étude prospective a été réalisée auprès de 18 patients qui subissaient un pontage aortocoronarien avec circulation extracorporelle (CEC) légèrement hypothermique. Le VSc a été mesuré selon les deux méthodes 24 h après l’admission à l’USI. Les données appariées ont été évaluées en valeur absolue et le pourcentage d’erreur a été calculé par le degré de concordance.Résultats: De faibles différences moyennes et écarts types entre la méthode CO et la méthode51Cr (−70,2±184,8 mL) et de bas pourcentages d’erreur (−0,49±1,29%) ont indiqué la justesse et la précision de la méthode CO, et une corrélation étroite a été observée (r=0,97).Conclusion: La méthode CO peut servir à mesurer le VSc avec un degré d’exactitude semblable à celui de la méthode51Cr. Elle est simple, répétable et sécuritaire, sans risque d’exposition à la radioactivité dans l’USI.

Screening cost for abdominal aortic aneurysms: Japan-based estimates.

PurposeThe aim of this study was to evaluate the screening procedures in Japan economically focusing on the screening costs and the hospital costs for abdominal aortic aneurysm (AAA) surgery.MethodsA total of 10 057 residents, 60 years of age or older, including 4 247 men and 5 810 women, participated in the screening test for AAA using ultrasound.ResultsAneurysms were detected in 34 participants, including 32 men and 2 women. The detection rate of AAA was 0.8% in men, 0.03% in women, and 0.3% in total. It cost US

PEEP Therapy for Patients With Pleurotomy During Coronary Artery Bypass Grafting

8 to screen each participant, and the cost to detect each aneurysm was thus estimated at

Thoracoscopic Closure of a Congenital Partial Pericardial Defect

1 250 in men,

Arterial embolization as preoperative treatment for pulmonary aspergillosis with hemoptysis

23 240 in women, and

Comparison of the hemodynamic effects of amrinone in patients who required low-to-moderate-dose and high-dose catecholamines after cardiac valve replacement.

2 366 in total. The difference in the mean hospital cost between ruptured and nonruptured AAA was