363 research outputs found
Factors Affecting Surfactant Responsiveness: Influence of mode of administration and ventilation, disease stage and type of surfactant
Historically, Kurt von Neergaard was the first to suggest that surface tension plays
an important role in lung elasticity. He showed, in 1929, that the pressure necessary
for fIlling the lung with liquid was less than half the pressure necessary for filling the
lung WiOl air, and concluded that two-thirds to three-fourths of the elasticity of the lung
was derived from interfacial forces. The problem with his discovery was that this
paper was published in Gemlan and that, for 25 years, no scientists in the evolving fIeld
really took note of this pnblication. In 1954, Macklin described the presence of a
thin aqueous mucoid microfIlm, formed from secretion of the granular pneumocytes,
on the pnlmonary alveolar walls and which is in constant slow movement toward the
phagocytic pneumocytes and bronchioles. One year later, Pattie noticed the
remarkable stability of foam and bubbles from lung edema and healthy lung cut. He
assumed that the walls of these bubbles consists of surface-active material which must
lower the surface tension to nearly zero. In 1957, Clements [was the fIrst to prove
the direct evidence of surface active material in the lungs. He measured surface tension
of a surface fIlm derived from the lung by using a Wilhelmy balance and demonstrated
that the surface tension was not a constant value; when the surface was stretched the
tension was relatively high (40 dynes/cm), but when the surface area was decreased the
tension fell to 10 dynes/cm. He pointed out that such a reduction in surface tension
during deflation in the lung would tend to stabilize the air spaces by permitting them
to remain open at low lung volumes. Two years later, Avery and Mead
demonstrated that lung extracts of very small premature infants and infants dying with
hyaline membrane disease had much higher surface tension than normal lung extracts,
due to
Gram-negative antibiotic resistance: there is a price to pay
Resistance rates are increasing among several problematic Gram-negative pathogens that are often responsible for serious nosocomial infections, including Acinetobacter spp., Pseudomonas aeruginosa, and (because of their production of extended-spectrum β-lactamase) Enterobacteriaceae. The presence of multiresistant strains of these organisms has been associated with prolonged hospital stays, higher health care costs, and increased mortality, particularly when initial antibiotic therapy does not provide coverage of the causative pathogen. Conversely, with high rates of appropriate initial antibiotic therapy, infections caused by multiresistant Gram-negative pathogens do not negatively influence patient outcomes or costs. Taken together, these observations underscore the importance of a 'hit hard and hit fast' approach to treating serious nosocomial infections, particularly when it is suspected that multiresistant pathogens are responsible. They also point to the need for a multidisciplinary effort to combat resistance, which should include improved antimicrobial stewardship, increased resources for infection control, and development of new antimicrobial agents with activity against multiresistant Gram-negative pathogens
Electrical impedance tomography and trans-pulmonary pressure measurements in a patient with extreme respiratory drive
Preserving spontaneous breathing during mechanical ventilation prevents muscle atrophy of the diaphragm, but may lead to ventilator induced lung injury (VILI). We present a case in which monitoring of trans-pulmonary pressure and ventilation distribution using Electrical Impedance Tomography (EIT) provided essential information for preventing VILI
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