sodium-pertechnetate-tc-99m and Respiratory-Distress-Syndrome

Topics: Acute Disease; Administration, Inhalation; Adult; Chagas Cardiomyopathy; Diagnosis, Differential; Diagnostic Errors; Female; Humans; Lupus Vulgaris; Pulmonary Embolism; Radionuclide Imaging; Radiopharmaceuticals; Rare Diseases; Respiratory Distress Syndrome; Sodium Pertechnetate Tc 99m; Ventilation-Perfusion Ratio

Aortic surgery results in ischemia/reperfusion of the lower body. This may liberate inflammatory mediators that activate neutrophils, and may result in lung microvascular changes with increased permeability and respiratory failure. We studied circulating inflammatory mediators and the pulmonary leak index (PLI) of 67Ga, a measure of transvascular transferrin transport and permeability, in patients scheduled for elective aortic and peripheral vascular surgery, before and after surgery. Aortic surgery patients in Groups 1 (n = 10) and 2 (n = 7) were studied before and at a median of 2.5 and 21.0 h after surgery, respectively. A control Group 3 (n = 6) was studied before and at a median of 2.9 h after peripheral vascular surgery. The PLI (median) increased from a median of 9.1 (range, 6.6 to 14.7) before to a median of 23.4 (range, 18.7 to 86.4) x 10(-3)/min after surgery in Group 1 but not in the other groups (p < 0.001). The postoperative increase in circulating neutrophils and elastase-alpha 1-antitrypsin, a marker of neutrophil activation, was similar among the groups. Plasma levels of activated complement 3a and tumor necrosis factor (TNF-alpha) did not change in any of the groups. In contrast, plasma levels of interleukin-8 (IL-8) increased in Group 1 from < 3 (range, < 3 to 37) before to 324 (range, 36 to 868) pg/ml after surgery, but did not change in the other groups (p < 0.005). The decrease in plasma levels of angiotensin converting enzyme (ACE) was greater in Group 1 than in the other groups (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aged; Aortic Diseases; Capillary Permeability; Citrates; Citric Acid; Erythrocytes; Female; Gallium Radioisotopes; Humans; Inflammation Mediators; Interleukin-8; Lung; Male; Middle Aged; Neutrophil Activation; Peptidyl-Dipeptidase A; Peripheral Vascular Diseases; Postoperative Complications; Radionuclide Imaging; Reperfusion Injury; Respiratory Distress Syndrome; Sodium Pertechnetate Tc 99m

A commercially available system of caesium iodide crystal mini-detectors (Oakfield Instruments, Oxon, UK) was modified so that it was suitable for dual isotopic measurement of the plasma protein accumulation index (PPA)- a measure of pulmonary endothelial permeability. Using this modified system the mean PPA x 10(-3) min-1 +/- (S.E.M.) recorded in 11 normal subjects (22 lungs) was 0.18 (0.08) and in 6 patients (9 lungs) with the adult respiratory distress syndrome was 2.88 (0.63) (P less than 0.02). These values for PPA concur with those found by other groups using larger sodium iodide detectors. We conclude that with simple modification caesium iodide mini-detectors may be used successfully for the measurement of PPA in the intensive care setting.

Topics: Capillary Permeability; Cesium; Humans; Indium; Iodides; Lung; Radionuclide Imaging; Respiratory Distress Syndrome; Scintillation Counting; Sodium Pertechnetate Tc 99m

1. The accumulation in the lung of the plasma protein transferrin was determined in 44 patients with widespread pulmonary infiltrates of various causes and in 11 healthy volunteers using a double-isotope method based on labelling in vivo of circulating transferrin with indium and erythrocytes with technetium. 2. In 22 patients meeting criteria for the adult respiratory distress syndrome (ARDS) the mean transferrin accumulation rate was threefold greater (P less than 0.005) than in 22 patients not meeting these criteria, although most possessed an appropriate risk factor for ARDS, in addition to extensive radiographic changes. 3. The double-isotope method did not completely separate patients with ARDS from those not meeting the criteria or from control subjects and cannot be considered a diagnostic test for the condition. Statistically significant rates of transferrin accumulation, however, occurred more frequently in patients with ARDS (82%) than in controls (64%) or in those without ARDS (59%).

Topics: Adolescent; Adult; Aged; Female; Humans; Indium Radioisotopes; Lung; Male; Methods; Middle Aged; Respiratory Distress Syndrome; Sodium Pertechnetate Tc 99m; Transferrin

Increased microvascular permeability resulting in increased plasma protein extravasation is the hallmark of acute inflammatory oedema and hence radiolabelled proteins can be used to monitor this process. The adult respiratory distress syndrome (ARDS) is characterized by acute inflammatory oedema and thus provides an ideal model for studying this type of oedema in the human lung. A noninvasive technique applicable to the intensive care unit has been developed for monitoring the pulmonary accumulation of the plasma protein transferrin. Transferrin was radiolabelled in vivo with indium-113m and its accumulation was monitored using a portable probe radiation detector. After correcting for changes in intrathoracic blood distribution, by simultaneously monitoring the accumulation of technetium-99m-labelled red blood cells, an index of plasma protein accumulation was calculated. In all patients with established ARDS (n = 10) the index values were greater than 1.0 X 10(-3) min-1 and these were clearly separate from the values of less than 0.5 X 10(-3) min-1 in all healthy volunteers (n = 5; P less than 0.001). The technique can clearly detect raised plasma protein accumulation indices in the lungs of patients with established inflammatory oedema of ARDS and hence may provide a pharmacological tool for the rapid evaluation in these conditions of the effects of drugs (like corticosteroids) which are known to modulate inflammatory oedema.

Topics: Capillary Permeability; Humans; Indium; Lung; Methods; Microcirculation; Radioisotopes; Radionuclide Imaging; Respiratory Distress Syndrome; Sodium Pertechnetate Tc 99m; Transferrin