Shinsaku Matsumoto

Hemodynamic effects of nifedipine in congestive heart failure

Nifedipine, a potent coronary vasodilator, was administered in a single sublingual dose of 20 mg to eight patients with mild to moderate congestive heart failure. Nifedipine produced a slight increase in heart rate (mean +/- standard error of the mean 73.3 +/- 3.2 versus 80.9 +/- 2.1 beats/min, p < 0.025) and an increase in cardiac index (from a control value of 3.51 +/- 0.22 to 4.06 +/- 0.31 liters/min per m2, p < 0.01). Arterial blood pressure decreased from 112.9 +/- 6.2/67.7 +/- 4.2 (mean 84.9 +/- 4.0) to 100.8 +/- 4.4/56.4 +/- 11.0 (mean 76.1 +/- 4.3) mm Hg (p < 0.01) and total systemic vascular resistance also decreased from a control value of 15.6 +/- 1.0 to 12.4 +/- 0.8 units (p < 0.01) after administration of nifedipine. These data suggest that nifedipine may be useful for vasodilation in congestive heart failure.

The rate of cardiac structural protein synthesis in perfused heart.

Synthesis of cardiac structural protein was studied in perfused rabbit hearts using [3H]lysine and perfluorochemical blood substitute. Relative synthesis rate was estimated in adult rabbit heart when both ventricles worked against zero pressure. The decreasing order was troponin complex, actinin complex, myosin, tropomyosin, and actin and was almost the same as that found in an in vivo study. The synthesis rates of myosin B in left and right ventricles were almost equal in hearts without left and right ventricular pressure load. In young rabbit heart with a right ventricular pressure load, an increase in the synthesis rate of right ventricular myosin B was observed along with the concomitant increase in that of left ventricle. As those increases were blocked by neither propranolol nor verapamil, it was suggested that these increases were not mediated by Ca2+ influx or beta-adrenergic receptors.

Oxygen management in mechanically ventilated patients: A multicenter prospective observational study

Purpose: To observe arterial oxygen in relation to fraction of inspired oxygen (FIO2) during mechanical ventilation (MV). Materials and methods: In this multicenter prospective observational study, we included adult patients required MV for >48 h during the period from March to May 2015. We obtained FIO2, PaO2 and SaO2 from commencement of MV until the 7th day of MV in the ICU. Results: We included 454 patients from 28 ICUs in this study. The median APACHE II score was 22. Median values of FIO2, PaO2 and SaO2 were 0.40, 96 mm Hg and 98%. After day two, patients spent most of their time with a FIO2 between 0.3 and 0.49 with median PaO2 of approximately 90 mm Hg and SaO2 of 97%. PaO2 was ≥100 mm Hg during 47.2% of the study period and was ≥130 mm Hg during 18.4% of the study period. FIO2 was more likely decreased when PaO2 was ≥130 mm Hg or SaO2 was ≥99% with a FIO2 of 0.5 or greater. When FIO2 was <0.5, however, FIO2 was less likely decreased regardless of the value of PaO2 and SaO2. Conclusions: In our multicenter prospective study, we found that hyperoxemia was common and that hyperoxemia was not corrected. HIGHLIGHTSThis is multicentre prospective study to observe the oxygen management in ventilated patients.Hyperoxemia was common as PaO2 was ≥100 mm Hg during 47.2% of the study period.Hyperoxemia was not corrected as FIO2 was less likely decreased when FIO2 was <0.5.