We measured the tidal volume achieved during intermittent positive pressure ventilation using various inspiratory times with a minimum of 0.2 seconds. Results indicate that tidal volume shows no reduction with inspiratory times down to 0.4 seconds. An inspiratory time of 0.3 seconds, however, is likely to reduce tidal volume by 8%, and at 0.2 seconds a 22% fall may be anticipated.

Introduction Dynamic arterial elastance (Eadyn), the relationship between pulse pressure variation (PPV) and stroke volume variation (SVV), has been suggested as a functional assessment of arterial load for predicting the arterial pressure response after volume expansion (VE). Although changes in Eadyn have been related with variations in arterial load, the effect of acute arterial tone changes...

Aim: The aim of this study was to emphasize two different points in our work: 1) The well known importance of (subclinical) postural hypotension and reduced heart rate variability as (early) markers of autonomic neuropathy; 2) and the more controversial influence of diabetic control in their worsening. Methods: Two standard cardiovascular response tests (heart rate variability by respiration an...

The use of intermittent positive-pressure ventilation via nasal mask with a rocking bed provided the necessary ventilatory support for a person with quadriplegia living at home. This option was required to maintain an independent life-style of choice. The combination of techniques and the linkage of devices demonstrated an effective use of simple available technology for respiratory care at hom...

1. Are arterial blood pressure fluctuations buffered or reinforced by respiratory sinus arrhythmia (RSA)? There is still considerable debate about this simple question. Different results have been obtained, triggering a discussion as to whether or not the baroreflexes are responsible for RSA. We suspected that the measurements of different aspects of arterial pressure (mean arterial pressure (M...

Recent experimental studies suggest that there is evidence for a synchronization between human heartbeat and respiration. We develop a physiologically plausible model for this cardiorespiratory synchronization, and numerically show that the model can exhibit stable synchronization against given perturbations. In our model, in addition to the well-known influence of respiration on heartbeat, the...

Alveolar partial pressure of carbon dioxide (PACO2) and alveolar partial pressure of oxygen (PAO2) oscillate at the frequency of respiration and the oscillations persist into the arterial blood as oscillations of arterial partial pressure of carbon dioxide (PaCO2) and arterial partial pressure of oxygen (PaO2). Arterial chemoreceptors respond quickly enough to changes in PaCO2 and PaO2 for the ...

To investigate the nature of variations in the large intestine potential differences, a continuous perfusion of isotonic saline was carried out in the colon of 14 rats. Intraluminal pressure and potential differences between the lumen and the peritoneal cavity were continuously and simultaneously recorded, while impedance of the system and respiration were also constantly monitored. To obtain a...

background changes in vital signs may affect the myocardial oxygen demand. massage therapy has been used in intensive care units to relive patients’ physical and psychological problems. in all of the studies massaging has been done by a nurse and the patients’ family did not have any role. objectives the present study aimed to examine the effects of massage therapy by patient’s relative on vita...

We describe a model predicting the effects of low environmental oxygen on vital rates (egg production, somatic growth, and mortality) of the coastal planktonic copepod Acartia tonsa. Hypoxic conditions can result in respiration rate being directly limited by oxygen availability. We hypothesized that A. tonsa egg production, somatic growth, and ingestion rates would all respond in a similar mann...