The volume of a tracheal system influences breath-holding capacity and provides an index of an insect's investment in its respiratory system. Here, we describe a new, generally applicable method to measure tracheal volume that enables repeatable determinations on live animals. Animals are isolated in a closed chamber of a known volume and equilibrated with a helium:oxygen gas mixture. The chamb...

INTRODUCTION Atelectasis is a common finding in acute lung injury, leading to increased shunt and hypoxemia. Current treatment strategies aim to recruit alveoli for gas exchange. Improvement in oxygenation is commonly used to detect recruitment, although the assumption that gas exchange parameters adequately represent the mechanical process of alveolar opening has not been proven so far. The ai...

This paper presents a new interactive method for analyzing 4D Computed Tomography (4DCT) datasets for patient care and research. Deformable registration algorithms are commonly used to observe the trajectories of individual voxels from one respiratory phase to another. Our system provides users with the capability to visualize these trajectories while simultaneously rendering anatomical volumes...

Dynamic-Contrast Enhanced MRI (DCE-MRI) is a method to analyze the perfusion dynamics in the tissues. The contrast agent concentration along the time, after the bolus injection, depends on the type of tissue observed, namely on its vascularization density and metabolic activity. The number of acquired volumes in this type of exam is usually very small, typically < 10, and the volumes are misali...

We have examined the effect of varying end-expiratory lung volume on carbon dioxide elimination in 10 mongrel dogs undergoing conventional mechanical ventilation at 12 b.p.m. and forced diffusion ventilation (FDV) at 6 Hz and 50 Hz and continuous flow. End-expiratory volumes were altered by changing the pressure in a plethysmographic box in which the dogs underwent ventilation. The pressures st...

A patient with acute respiratory failure secondary to leptospirosis was treated with 40 and 90 volumes per million inhaled nitric oxide. His serum nitrogen oxide concentration (nitrates and nitrites combined) increased 13-fold. The mechanisms for the formation and elimination of nitrates are discussed.

The Mechanics of Breathing and Stabilization of Ventilation in Patients With Unilateral Cerebral Infarction • The mechanics of breathing and responses of the respiratory system to CO2 during resistance breathing were studied in 12 patients with clinical evidence of unilateral cerebral infarction and compared with the findings in normal subjects. The respiratory abnormalities in patients with ce...

The initiation of ventilation in the delivery room is one of the most important but least controlled interventions a preterm infant will face. Tidal volumes (V T) used in the neonatal intensive care unit are carefully measured and adjusted. However, the V Ts that an infant receives during resuscitation are usually unmonitored and highly variable. Inappropriate V Ts delivered to preterm infants ...

Acute respiratory failure is commonly encountered in the emergency department (ED), and early treatment can have effects on long-term outcome. Noninvasive ventilation is commonly used for patients with respiratory failure and has been demonstrated to improve outcomes in acute exacerbations of chronic obstructive lung disease and congestive heart failure, but should be used carefully, if at all,...

Methods have been developed to isolate mitochondria from small amounts of normal and leukemic human lymphocytes obtained from small volumes of circulating blood. Mitochondrial respiratory functions were measured by polarographic techniques, and active calcium uptake was measured by a spectrophotometric procedure utilizing the calcium-sensitive dye murexide. The results indicate that the rates o...