Effect of inspiratory resistance and PEEP on /sup 99m/Tc-DTPA clearance

Journal Article · Thu May 01 04:00:00 EDT 1986 · J. Appl. Physiol.; (United States)

OSTI ID:5204406

O'Brodovich, H; Coates, G; Marrin, M

Experiments were performed to determine the effect of markedly negative pleural pressure (Ppl) or positive end-expiratory pressure (PEEP) on the pulmonary clearance (k) of technetium-99m-labeled diethylenetriaminepentaacetic acid (/sup 99m/Tc-DTPA). A submicronic aerosol containing /sup 99m/Tc-DTPA was insufflated into the lungs of anesthetized intubated sheep. In six experiments k was 0.44 +/- 0.46% (SD)/min during the initial 30 min and was unchanged during the subsequent 30-min interval (k = 0.21 +/- 12%/min) when there was markedly increased inspiratory resistance. A 3-mm-diam orifice in the inspiratory tubing created the resistance. It resulted on average in a 13-cmH2O decrease in inspiratory Ppl. In eight additional experiments sheep were exposed to 2, 10, and 15 cmH2O PEEP (20 min at each level). During 2 cmH2O PEEP k = 0.47 +/- 0.15%/min, and clearance increased slightly at 10 cmH2O PEEP (0.76 +/- 0.28%/min, P less than 0.01). When PEEP was increased to 15 cmH2O a marked increase in clearance occurred (k = 1.95 +/- 1.08%/min, P less than 0.001). The experiments demonstrate that markedly negative inspiratory pressures do not accelerate the clearance of /sup 99m/Tc-DTPA from normal lungs. The effect of PEEP on k is nonlinear, with large effects being seen only with very large increases in PEEP.

• Research Organization: McMaster Univ. Health Sciences Centre, Hamilton, Ontario
• OSTI ID: 5204406
• Journal Information: J. Appl. Physiol.; (United States), Journal Name: J. Appl. Physiol.; (United States) Vol. 5; ISSN JAPYA
• Country of Publication: United States
• Language: English

Related Subjects

550601 -- Medicine-- Unsealed Radionuclides in Diagnostics
551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
AEROSOLS
AMINO ACIDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MODELS
CARBOXYLIC ACIDS
CHELATING AGENTS
CLEARANCE
COLLOIDS
DISPERSIONS
DOMESTIC ANIMALS
DRUGS
DTPA
DYNAMIC FUNCTION STUDIES
EXCRETION
HOURS LIVING RADIOISOTOPES
INHALATION
INTAKE
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
LUNG CLEARANCE
MAMMALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
RADIOISOTOPES
RADIOPROTECTIVE SUBSTANCES
RUMINANTS
SHEEP
SOLS
TECHNETIUM 99
TECHNETIUM ISOTOPES
VERTEBRATES
YEARS LIVING RADIOISOTOPES