1.
Unaffected contractility of diaphragm muscle fibers in humans on mechanical ventilation.
Hooijman, PE, Paul, MA, Stienen, GJ, Beishuizen, A, Van Hees, HW, Singhal, S, Bashir, M, Budak, MT, Morgen, J, Barsotti, RJ, et al
American journal of physiology. Lung cellular and molecular physiology. 2014;(6):L460-70
Abstract
Several studies have indicated that diaphragm dysfunction develops in patients on mechanical ventilation (MV). Here, we tested the hypothesis that the contractility of sarcomeres, i.e., the smallest contractile unit in muscle, is affected in humans on MV. To this end, we compared diaphragm muscle fibers of nine brain-dead organ donors (cases) that had been on MV for 26 ± 5 h with diaphragm muscle fibers from nine patients (controls) undergoing surgery for lung cancer that had been on MV for less than 2 h. In each diaphragm specimen we determined 1) muscle fiber cross-sectional area in cryosections by immunohistochemical methods and 2) the contractile performance of permeabilized single muscle fibers by means of maximum specific force, kinetics of cross-bridge cycling by rate of tension redevelopment, myosin heavy chain content and concentration, and calcium sensitivity of force of slow-twitch and fast-twitch muscle fibers. In case subjects, we noted no statistically significant decrease in outcomes compared with controls in slow-twitch or fast-twitch muscle fibers. These observations indicate that 26 h of MV of humans is not invariably associated with changes in the contractile performance of sarcomeres in the diaphragm.
2.
[Effect of shenmai injection on diaphragmatic fatigue in children with respiratory failure].
Yan, CX, Yang, YG, Zhang, ZX
Zhongguo Zhong xi yi jie he za zhi Zhongguo Zhongxiyi jiehe zazhi = Chinese journal of integrated traditional and Western medicine. 2002;(6):426-8
Abstract
OBJECTIVE To study the effect of Shenmai injection (SMI) on diaphragmatic fatigue in children with respiratory failure. METHODS Thirty-five cases of children respiratory failure with diaphragmatic fatigue were divided into two groups. The control group was treated with comprehensive therapy including anti-infection, oxygen inhalation and parenteral nutrition, etc. The SMI group was treated with SMI intravenously, besides the comprehensive therapy as in the control group. Taking electrical impedance respirogram (IRG) as criterion of therapeutic effect, the effective cases after 30 min medication, time for diaphragmatic fatigue disappearance, as well as arterial blood gas analysis before and after treatment were analyzed. RESULTS (1) In 30 min after medication, the effective cases in the SMI group (15/18) were more than that in the control group (4/17, P < 0.01); (2) Blood pH increased and PaCO2 decreased in both groups after treatment, but the decrease of PaCO2 was more significant in the SMI group (P < 0.05); (3) Time of diaphragmatic fatigue disappearance in the SMI group was shorter than that in the control group (P < 0.01). CONCLUSION SMI is an effective drug for treatment of diaphragmatic fatigue in children with less adverse effect, and worthwhile for spreading in clinical practice.