Altered diaphragmatic contractile properties after high airway pressure controlled mechanical ventilation

Acute respiratory failure is the most frequent indication for the application of mechanical ventilation. As commonly used in clinical settings, lung protective strategies and recruitment manoeuvres are applications of higher than normal airway pressure to open the collapsed alveoli and prevent lung atelectasis caused by minimal vital ventilation. Under those conditions, we pay more attention to the lung injury and circulatory failure,

The Effects of Ground and Treadmill Running on Energy Metabolism and Muscle Contractile Properties:A Randomized Cross-Over Study

Purpose This study aimed to compare the effects of ground and treadmill running on energy metabolism and muscle con-tractile properties,providing a basis for the general public to choose running venues.Methods Ten male college students(age,20.10±1.53 years;height,176.20±5.49 cm;weight,72.14±8.25 kg;body fat percent,12.41%±4.65%)were recruited in this study.Energy expenditure(EE)was measured using the accelerometer(GT9X)combined with specific estimation equations.Average heart rate(HR)was measured using a heart rate band(Polar).Muscle contractile properties were assessed by measuring muscle displacement(Dm)and contraction velocity(Vc)using tensiomyography(TMG-S1).Blood glucose(Glu)and lactate(Lac)were measured by portable devices(eB-G and Lactate Scout).The running speed was 9 km/h and the duration was 25 min.Two-way ANOVA(protocol×time)was used to analyze the effect of running protocols on energy metabolism and muscle contractile properties.Results EE of treadmill running was significantly higher than EE of ground running(protocol main effect,P<0.001),and HR of treadmill running was significantly higher than that of ground running in the first testing time(protocol simple effect,P=0.026;protocol×time interaction P=0.043).The decrease in Dm of the rectus femoris after treadmill running was significantly higher than that of ground running(protocol main effect,P=0.009).The interaction of different running protocols and testing times on Lac was significant(P=0.025),but all results of the simple effects analysis were not statisti-cally significant(P>0.05).Conclusion Our study found a difference in energy expenditure between treadmill and ground running at 9 km/h with duration of 25 min.In addition,treadmills are more likely to cause a decrease in muscle displacement distance of the rectus femoris measured after exercise than ground running.Future studies are needed to further investigate whether the differences are induced by internal metabolism or the environmental conditions of running.