results sixty patients were involved in this study. in asv mode, values including peak airway pressure (p-peak), end-tidal carbon dioxide (etco2), tidal volume and respiratory dead space were significantly lower than simv mode. although the mean value for dynamic compliance had no significant difference in the two types of ventilation, it was better in asv mode. methods in a crossover study, pa...

When physiological dead space (Vd(p)) is calculated for a patient who has alveolar dead space, e.g., after pulmonary vascular occlusion, less than the full volume of attached mechanical dead space (Vd(m)) appears in the measured dead space (Vd(n)). Under these conditions the traditional subtraction of Vd(m) from Vd(n) leads to underestimation of Vd(p) and can give a falsely small ratio of Vd(p)...

As the quality of rehabilitation has improved (e.g., through the increased use of wheelchairs), ischial sores have become one of the top 3 most common types of sores in terms of location, with an annually increasing number of patients [1]. Even after musculocutaneous or perforator flaps are performed to treat pressure sores, complications such as ulcer recurrence and wound dehiscence still rema...

Background. Respiratory dead-space is often increased in lung disease. This study evaluates the effects of increased alveolar dead-space (VDalv), pulmonary shunt, and abnormal ventilation perfusion ratio ( _ V= _ Q) distributions on dead-space and alveolar partial pressure of carbon dioxide (PACO2) calculated by various methods, assesses a recently published non-invasive method (Koulouris metho...

Anatomical dead space was measured in 72 normal children aged from 5 to 16 years, using the single breath method. There was a linear increase in this measurement with height, weight, and end-inspiratory lung volume. Physiological dead space was measured in 52 normal children using the Bohr equation and substituting a rebreathing PCO2 for alveolar PCO2. There was a parallel increase in this meas...

Wound debridement refers to the removal of necrotic, devitalized, or contaminated tissue and/or foreign material to promote wound healing. Surgical debridement uses sharp instruments to cut dead tissue from a wound and it is the quickest and most efficient method of debridement. A wound debridement simulator can ensure that a medical trainee is competent prior to performing a procedure on a gen...

Fowler ( 1 ) estimated the respiratory dead space in man by recording simultaneously and continuously the nitrogen concentration and the volume flow at the mouth during a single expiration, following a breath of oxygen. Such an expiration may be divided into three phases. In the first part of expiration there is virtually no nitrogen. This is followed by an S-shaped rise in nitrogen concentrati...

Since around 1950, physiological dead space - the difference between arterial and mixed expired pCO2 (partial pressure of carbon dioxide) divided by the arterial pCO2 - has been a useful clinical parameter of pulmonary gas exchange. In the previous issue of Critical Care, Niklason and colleagues remind us that physiological dead space, while easily measured, consolidates potentially very comple...

BACKGROUND Anatomical dead space is usually measured using the Fowler equal area method. Alternative methods include the Hatch, Cumming, and Bowes methods, in which first, second, and third order polynomials, respectively, fitted to an expired CO2 volume vs expired volume curve, intercept the x-axis at the anatomical dead space. This study assessed systematic errors and susceptibility to noise ...