Biomedical subjects

E Evander

Publications and source records attributed to E Evander.

26 records · Page 2Linked to original sources

PubMed1990

Pulmonary clearance of inhaled [99Tcm]DTPA: effects of ventilation pattern.

While a rise in lung volume is known to increase the pulmonary clearance of technetium-99m-labelled dietylene triamine pentaacetate ([99Tcm]DTPA), little interest has been focused on the effects of changes in ventilation frequency, tidal volume and airway pressure. We studied adult, anaesthetized and intubated rabbits during three ventilation patterns (VP) using pressure controlled ventilation (ServoVentilator 900C). VP was either deep slow (f = 20 min-1, tidal volume (VT) = 30 +/- 4 ml kg-1 and positive end-expiratory pressure (PEEP) = 0.2 kPa [VP 20/0.2, n = 8]) or rapid shallow (f = 80 min-1, VT = 11 +/- 2 ml kg-1 and PEEP = 0.2 or 0.4 kPa [VP 80/0.2, n = 6 and VP 80/0.4, n = 6]). The mean airway pressure was similar at VP 20/0.2 and VP 80/0.4. During administration of [99Tcm]DTPA aerosol all animals were ventilated under the same conditions (f = 40 min-1 and PEEP = 0.2 kPa). The pulmonary clearance rate expressed as the half-life time (T1/2) of [99Tcm]DTPA was at VP 80/0.2 = 113 +/- 31 min, at VP 80/0.4 = 70 +/- 24 min (P less than 0.01 compared to VP 80/0.2) and at VP 20/0.2 = 36 +/- 18 min (P less than 0.001 compared to VP 80/0.2 and P less than 0.01 compared to VP 80/0.4). We conclude that the pulmonary clearance of [99Tcm]DTPA increases (1) during rapid shallow ventilation when PEEP is increased from 0.2 to 0.4 kPa; (2) during deep slow ventilation relative to rapid shallow ventilation even when the mean airway pressure is similar.

Animals↗

PubMed1990

Distribution of renal parenchymal damage on 99m-Tc DMSA scintigraphy in vesico-ureteric reflux.

During a 2 year period renal scintigraphy was performed in 64 children prior to surgery for vesico-ureteric reflux (VUR). In total 126 kidneys were examined. Renal scintigraphy was performed 3 hours after intravenous injection of 99m-technetium labelled dimercaptosuccinic acid (DMSA). The renal parenchyma was assessed as normal in 64 kidneys and abnormal in 62. Renal parenchymal damage was revealed in the upper pole in 42 cases, the middle lateral part in 27, the lower pole in 47 and the middle medial part in 25. The whole kidney was affected in 21 cases. Damage within one or two poles was present in 59 of the 62 kidneys with parenchymal damage. Renal scintigraphy is regarded a sensitive technique for detection of renal parenchymal damage. The DMSA scintigraphy can reveal even minor scars. It can be recommended as a routine investigation in evaluating children with VUR.

Child↗

PubMed1989

Renal parenchymal damage on DMSA-scintigraphy in pelviureteric obstruction.

During a 1.5 year period 21 children were investigated with 99-m-technetium dimercaptosuccinic acid (DMSA) before operation for hydronephrosis due to pelviureteric obstruction. The age at investigation was 0.2-11.5 years. Fourty-two kidneys were examined. Hydronephrosis existed on the right side in 8 cases, left side in 9 and bilateral in 4 cases. Seventeen kidneys had no obstruction. The scintigraphy was interpreted as normal in 19 kidneys. Decreased isotope uptake was found in 23 kidneys and localized to the upper pole area in 19 kidneys, middle-lateral part in 7, lower pole area in 15 and the middle-medial part in 12 kidneys. There were no predominance for any part of the kidney to be affected by parenchymal damage. In 8 children investigated before the age of 1 year, 4 of 10 hydronephrotic kidneys revealed normal DMSA scintigram. DMSA scintigraphy delineates functioning renal parenchyma. DMSA scintigraphy delineates functioning renal parenchyma. It can be recommended as a routine method for evaluation of the renal parenchyma before surgery and for follow up studies in all ages of childhood.

Child↗

PubMed1988

Pulmonary clearance of inhaled 99mTc-DTPA: effect of the detergent dioctyl sodium sulfosuccinate in aerosol.

The influence of the detergent dioctyl sodium sulfosuccinate on clearance from the lungs of inhaled technetium-99m-labelled dietylenetriamine pentaacetate (99mTc-DTPA) was studied in twelve rabbits. An aerosol of dioctyl sodium sulfosuccinate or its vehicle alone was administered for 5 min prior to aerosolized 99mTc-DTPA via a bag-in-bottle system. Time-activity curves were obtained from the right lung with a gamma camera. In rabbits given detergent, clearance of 99mTc-DTPA was significantly faster than in rabbits given vehicle alone. No changes were seen in arterial PO2 and compliance. Our data indicates that the transfer of 99mTc-DTPA from alveoli to blood can be accelerated by administration of the detergent dioctyl sodium sulfosuccinate without any dramatic change in surface tension. Clearance of 99mTc-DTPA may be a very sensitive indicator of altered surfactant function.

Administration, Inhalation↗

PubMed1987

Pulmonary clearance of inhaled 99mTc-DTPA: effects of surfactant depletion by lung lavage.

The influence of surfactant depletion on clearance from the lungs of inhaled technetium-99m-labeled diethylenetriamine pentaacetate (99mTc-DTPA) was studied in rabbits. Surfactant was removed by repeated lung lavage with isotone saline. To minimize structural damage to the lungs, pressure generated insufflation with short expiration was utilized. Aerosolized 99mTc-DTPA was administered via a bag-in-bottle system. Radioactivity was measured with a gamma camera and time-activity curves were obtained over the base of the right lung. Six nonlavaged rabbits served as controls. In six lavaged rabbits clearance of 99mTc-DTPA was significantly faster than in controls. In three rabbits given natural surfactant into the trachea after lung lavage, 99mTc-DTPA was eliminated faster than in controls but slower than in surfactant-depleted animals. The results indicate a role of surfactant on clearance rate of 99mTc-DTPA from rabbit lungs. Measurements of 99mTc-DTPA clearance may be useful in studying the function of the surfactant system in different lung disorders.

Aerosols↗

PubMed1987

Pericardial effusion causes interstitial pulmonary edema in dogs.

The pulmonary effects of pericardial effusion were studied in eight anesthetized dogs, with emphasis on lung mechanics, O2 exchange, and extravascular thermal lung volume (ETV) accumulation, while warm saline was instilled into the pericardium to elevate pericardial pressure. The results were compared with those from four time-controlled and sham-operated dogs. ETV, as measured by a double-indicator technique, increased from 8.1 +/- 0.8 ml/kg at a pericardial pressure of 0 mm Hg to 12.9 +/- 2.1 ml/kg at 11.0 mm Hg (p less than .01). In the control group, ETV increased from 6.5 +/- 0.7 to 8.2 +/- 0.5 ml/kg over an equal time span. This increase in ETV in the experimental dogs was inversely related to pulmonary compliance, which decreased by 29% as ETV increased (p less than .05), whereas in the time-controlled group of animals it decreased by 8.8%. Arterial PO2 did not deteriorate during the protocol in either group. Histologic examination showed increased interstitial fluid, but neither alveolar fluid nor septal edema, and gravimetric measurements of lung liquid were also consistent with interstitial fluid accumulation in experimental but not control animals. These findings are concordant with the clinical observation that alveolar edema is rarely seen in the presence of pericardial tamponade. Conceivably, progression from interstitial to alveolar edema did not occur both because of the low pulmonary blood flow that occurs as part of pericardial tamponade physiology and/or because the hydrostatic pressures were not elevated enough to produce higher rates of fluid transudation.

Animals↗

PubMed1986

Pulmonary clearance of inhaled 99mTc-DTPA: effect of surfactant depletion in rabbits.

We examined the effect of surfactant depletion on the rate of pulmonary clearance of inhaled 99mTc-diethyl-triamino-penta-acetate (DTPA). 99mTc-DTPA was administered as a fine aerosol to four control animals and to four animals after wash-out of pulmonary surfactant. Care was taken to minimize structural damage to the lavaged lungs. Clearance of 99mTc-DTPA was measured over the right lung by external counting. The clearance rate was substantially increased in the lavaged animals compared to the control animals. We conclude that the pulmonary surfactant system is a rate-limiting factor for the absorption of inhaled 99mTc-DTPA. Measurement of the pulmonary clearance of 99mTc-DTPA may provide a new means for studying the pathogenetic role of the surfactant system in a variety of lung diseases.

Absorption↗

PubMed1983

Lung function and bronchial reactivity in six patients with immotile cilia syndrome.

Previous studies of immotile cilia syndrome have shown airway obstruction. The aim of this study was to analyse lung function in such patients before severe chronic obstruction had occurred. Spirometry, lung volumes, pulmonary resistance and static pressure volume diagram were studied in six patients (ages 21-43 years). Closing capacity, the volume of trapped gas and the slope of the alveolar plateau were determined with N2 wash-out tests. Regional ventilation was studied with a gamma camera after inhalation of 99Tcm-tagged dry aerosol. Arterial blood gases were determined at rest and during exercise. Bronchial reactivity was studied with FEV1 before and after inhalation of methacholine aerosol. Five of six patients showed a rather uniform pattern, dominated by signs of "small airway disease" seen in e.g. volumes of trapped gas and closing capacity. Those five patients had uneven ventilation scintiscans and bronchial hyperreactivity. Spirometric findings and lung mechanics were influenced by lung resection, scoliosis and by the lability of bronchial tone. Five patients had normal arterial blood gases at maximum work load. Working capacity was essentially normal in all but one patient, who had a high degree of obstruction. Immotile cilia syndrome is thus compatible with a comparatively well preserved lung function and a normal working capacity far into adult life.

Adult↗