INTRODUCTION The ventilator and the endotracheal tube impose additional workload in mechanically ventilated patients breathing spontaneously. The total work of breathing (WOB) includes elastic and resistive work. In a bench test we assessed the imposed WOB using 3100 A/3100 B SensorMedics high-frequency oscillatory ventilators. METHODS A computer-controlled piston-driven test lung was used to...

Previous research has suggested a relationship between low-frequency power of heart rate variability (HRV; LF in normalized units, LFnu) and muscle sympathetic nerve activity (MSNA). However, investigations have not systematically controlled for breathing, which can modulate both HRV and MSNA. Accordingly, the aims of this experiment were to investigate the possibility of parallel responses in ...

Spontaneous breathing effort of a mechanically ventilated patient can seriously deteriorate the treatment outcome if it is not taken into account when choosing appropriate settings. This paper presents an improved spontaneous model that be used to develop mechanical ventilation algorithms. Through indicative experimental study shown this accurately describes healthy human test subject. In compa...

INTRODUCTION With the 3100B high-frequency oscillatory ventilator (SensorMedics, Yorba Linda, CA, USA), patients' spontaneous breathing efforts result in a high level of imposed work of breathing (WOB). Therefore, spontaneous breathing often has to be suppressed during high-frequency oscillatory ventilation (HFOV). A demand-flow system was designed to reduce imposed WOB. METHODS An external g...

OBJECTIVES Intermittent periods of hypoxemia such as during periodic breathing are associated with hypertension and increased sympathetic activity. In patients with sleep apnea syndrome, hypertension is common. Treating apnea improves hypertension and reduces sympathetic outflow. The aim of the present study was to investigate the phenomenon and mechanisms of spontaneous periodic breathing in p...

Introduction Respiratory distress syndrome (RDS) is a current cause of morbidity in premature infants resulted from surfactant deficiency. The primary aim of this randomized study was to describe the feasibility of early administration of surfactant via a thin catheter during spontaneous breathing (TEC) and compare its outcomes with the InSurE (Intubate, Surfactant, Extubate) procedure Material...

purpose: patterned breathing allows standardized serial measurements of heart rate variability and baroreflex indices. the slow breathing augments these parameters, and regular exercises, including yoga breathing practices with even respiratory rates have long-term beneficial effects in cardiovascular diseases. the role of temporization of breathing phases, i.e. the ratio of expiration to inspi...

INTRODUCTION Long-term confinement and microgravity may entail alteration in the regulation of the cardiovascular system. A 105-d pilot study of a Mars mission simulation was conducted to test the cardiovascular response to slow-paced breathing and mental stress. METHODS Finger blood pressure and beat-to-beat heart rate were monitored in six male volunteers taking part in a 105-d Mars mission...