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Biomedical subjects

M Arborelius

Publications and source records attributed to M Arborelius.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1982

Scintigraphic evaluation of pulmonary embolism after total hip replacement, using a dry 99mTc-microaerosol for regional ventilation.

A new 99mTc-microaerosol was used for ventilation scintigraphy in combination with perfusion scintigraphy for studying the incidence of pulmonary embolism (PE) from 189 consecutive investigations in patients undergoing total hip replacement. Diagnostic criteria are presented. Perfusion defects of triangular shape were significantly more frequent in combination with ventilation mismatch (PE) than with ventilation match (not PE) (P less than 0.001). Reevaluation of the scintigrams more than 2 months later gave identical results in more than 90% of patients and as regards the diagnosis of PE, in 93%. Attacks of sudden chest pain were more frequent in patients with pulmonary embolism (P less than 0.01), but measurement of arterial blood gases did not discriminate between patients with and without PE. The 99mTc-microaerosol provides a high resolution and images that are directly comparable to perfusion studies using the same, easily available isotope. In many aspects this new microaerosol seems to be superior to previously described radioaerosols and to 133Xe for ventilation studies.

Aerosols↗
PubMed1982

Lung function studies in children with allergic rhinitis.

Thirty carefully selected children with seasonal allergic rhinitis but without history or signs of lung involvement were examined clinically and by lung function tests during the pollen season as well as in the pollen-free season. During the pollen-free season the children had - if anything - slightly better lung function than a healthy control material. During the pollen season the only change was a slight increase in FRC and a decrease in lung clearance index, directly proportional to the change in FRC. Sixteen of the children performed an exercise test in the pollen-free season. A small increase in the volume of trapped gas (VTG) was noted, indicating a subclinical spasm in small airways. Salbutamol inhalation after exercise reduced VTG below base-line values, indicating disappearance of subclinical bronchospasm. Hay fever children thus have a tendency towards bronchospasm after, exercise in the pollen-free season, which, however, is of no clinical importance, as their VTG also after the exercise was less (better) than the predicted normal.

Adolescent↗
PubMed1982

Generation of a microaerosol suitable for deposition in the peripheral airways.

A method is described for the production of a dry submicronic aerosol. A wet aerosol is first produced in a common jet aerosol apparatus, modified to retain particles larger than 2 micrometers. The aerosol is then dried by heating to 70 degrees C in an evaporation tube. The dry particles are mainly smaller than 0.5 micrometer. At inhalation the temperature drops below 40 degrees C and the dew point is reached so that water vapour condenses on the particles. About 95% of the particles were deposited past the large bronchi and about 87% were retained in the alveoli. The new technique renders very satisfactory ventilation scintigraphies as proven by experience from more than 200 subjects. It may also prove useful for depositing drug aerosols in the peripheral airways.

Aerosols↗
PubMed1981

Volume of trapped gas in lungs of healthy humans.

The volume of trapped gas (Vtg) that could be mobilized by maximal breaths at the end of a nitrogen washout to 2% N2 was measured in 70 healthy women and 62 healthy men while seated. The average Vtg was found to be 102 +/- 21 (SD) ml in men and 73 +/- 18 ml in women. The Vtg was positively related to total lung capacity (TLC) (r = 0.67; P less than 0.001). An average percent Vtg/TLC of 1.4 +/- 0.31 (DS) % was applicable to both sexes. Vtg/TLC (%) was positively related to age (4 = 0.45; P less than 0.001). The error of a single determination was 8 ml, i.e., the reproducibility was very high. The existence of lung compartments that are unventilated or extremely underventilated may explain part of the physiological alveolararterial O2 difference. An increase in Vt has been found to be a very sensitive sign of subclinical bronchospasm.

Adolescent↗
PubMed1981

Salbutamol inhalation in chronic asthma bronchiale: dose aerosol vs jet nebulizer.

The effect of inhalation of 5 mg of salbutamol by a jet nebulizer and 0.3 mg from a metered aerosol was compared in 20 patients with chronic asthma. Half the patients, randomly selected, received one treatment method on day one and the other on day two. A battery of lung function tests suitable for detecting large and small airways obstruction showed only insignificantly more pronounced bronchodilatation after the use of the jet nebulizer. Neither was a better dilation of small airways with this method obvious. It is concluded that the higher dose by jet-nebulizer is only clinically motivated when the patients cannot perform the deep inhalations and breathholding necessary for efficient use of the dose aerosol.

Adult↗
PubMed1980

Dynamic behaviour of the chest and of the abdomen in anaesthetized piglets during rapid insufflation.

Three piglets were ventilated with a TVM-ventilator, which releases predetermined volumes of compressed gas into the airways. The inspiratory flow depends on the pressure and volume of the compressed gas and compliance, resistance and inertia of the lungs, thorax and abdomen of the subject. The time for half filling of the chest was less than that of the abdomen and the difference increased with high driving pressure (with high acceleration). The difference was thus most probably a result of greater inertia of the abdomen. Inertia also seemed to influence the emptying of the lungs. This was so slow that increase of FRC--air trapping--was seen at a ventilatory frequency of 30 b.p.m. The practical consequences of these findings are that the abdomen (diaphragm) will take less and less part in ventilation and that a phase lag between chest and abdominal breathing should become larger with increasing ventilatory frequency. FRC will increase in regions with expiratory obstruction and lung rupture may follow.

Abdomen↗
PubMed1980

Lung function in cystic fibrosis: acute effect of salbutamol.

Pulmonary function tests including spirometry, N2 washout and volume of trapped gas (VTG) were obtained in 12 children with cystic fibrosis (CF), 6-18 years of age, before and after inhalation of 0.2 mg salbutamol. 11 children had pathologically increased VTG while the lung clearance index (LCI) was abnormal in 9, V'max 25/TLC (maximal flow at 25% of vital capacity/total lung capacity) in 8, residual volume in 6, but FEV1 in only 2 children. VTG/TLC% increased with age while V'max 25/TLC and FEV1 did not change. Neither was clinical score related to age in our subjects. No improvement in lung function occurred after salbutamol inhalation. VTG proved most sensitive for showing abnormality in children with CF.

Adolescent↗
PubMed1980

Crippled lung: variations on a theme by Macleod.

We have studied nine male patients (age 18 to 68 years) with radiographic and physiologic evidence of an abnormally small lung on one side (three right and six left). All had had a childhood pneumonia or bronchiolitis and eight had chronic or recurrent bronchitis and exertional dyspnea. Radiography showed two of the small lungs to be hypolucent while seven were hyperlucent. Bronchography revealed evidence of bilateral chronic bronchitis in all with saccular bronchiectasis in three. Angiography showed strikingly diminished vascularity to the smaller lung. Spirometry revealed airway obstruction in seven of the patients. All had pulmonary arterial hypertension. Radiospirometry showed that the small lung had on the average 30% of the total ventilation but only 15% of the perfusion. Washout of 133 Xe was extremely slow in radiolucent regions. We suggest the name "crippled lung" syndrome for this entity because it is purely descriptive and encompasses several clinical variants. It also avoids the pitfalls of etiologic implication (acquired-congenital). Clinical or subclinical bronchitis seems to be common in these patients and the prime goal in therapy must be to combat the tendency towards airway infection.

Adolescent↗
PubMed1980

Combined radionuclide phlebography and lung scanning in patients operated on for scoliosis with the Harrington procedure.

Iliac vein thrombosis is an uncommon type of deep vein thrombosis (DVT) that occurs in young patients following surgical procedures for scoliosis. The symptomatology is diffuse and this type of DVT carries a risk for fatal pulmonary embolism as well as the development of a postphlebitic syndrome. Combined radionuclide phlebography and lung scanning were performed in 16 patients operated on for scoliosis with the Harrington procedure. In three patients with diffuse pain in the inguinal region, iliac vein thrombosis was easily visualized in the radionuclide phlebogram and confirmed by conventional phlebography in two cases. Six patients without lung symptoms had perfusion defects typical for pulmonary embolism. It is concluded that radionuclide phlebography can be recommended as a diagnostic procedure for iliac vein thrombosis in patients with diffuse symptoms in the inguinal region or the lower abdomen after scoliosis surgery. Advantages include the ease of performance, good patient acceptance and low radiation dose compared with conventional phlebography. Asymptomatic pulmonary embolism as diagnosed by the perfusion lung scan was an unexpected finding which raised clinical considerations that require further investigations.

Adolescent↗
PubMed1979

Preoperative normovolaemic haemodilution with dextran 70 as a thromboembolic prophylaxis in total in hip replacement.

The effect of preoperative normovolaemic haemodilution with dextran 70 in 57 patients undergoing total hip replacement for osteoarthritis, was evaluated with respect to the production of thrombosis and pulmonary embolism. The patients were randomly allocated to one group undergoing preoperative haemodilution and one control group receiving 500 ml dextran 70 during operation and again on the second postoperative day. Before operation blood was replaced by dextran 70 to lower the hematocrit to between 25 and 30. The blood drained from the patients was used to replace blood lost at operation. Between 10 and 14 days after operation the patients were examined by perfusion lung scan, chest radiography and bilateral phlebography. Twelve patients also had 133Xe ventilation scans. The incidence of deep vein thrombosis in the two groups did not differ significantly. Pulmonary embolism was significantly decreased in the preoperative haemodilution group. One patient in the control group had clinical symptoms of, and died from, pulmonary embolism.

Aged↗
PubMed1979

Effects of nitroglycerin and dipyridamole on acute myocardial infarction: a thermographic study in the dog.

The effects on an acute myocardial infarction of equipotent hypotensive doses of nitroglycerin and dipyridamole were studied using the thermographic technique in open-chest dogs. Nitroglycerin did not reduce the cool ischaemic area in any of the nine dogs studied. In six of the dogs, in which the ischaemic region could be properly measured, the cool area slightly grew in size. Dipyridamole reduced the size of the ischaemic area in all the 20 dogs used. In the 19 in which the size could be adequately digitalised, the decrease in infarction size was statistically significant.

Acute Disease↗
PubMed1979

Influence of ventilatory frequencies and ventilator volume/pressure quotients on pulmonary ventilation using a tidal volume ventilator.

The influence of ventilatory frequency and the ventilator's "internal state of gas compression" (Cvent) on mechanics of ventilation, pulmonary ventilation, gas distribution, gas exchange and lung perfusion was studied with free airway and experimental regional airway obstruction in 10 piglets (7-12 kg b. w. ), using a tidal volume ventilator. The VDphy/VTexp ratio was greater at f = 30 than at f = 10.3 cycles/min. This could be related to a significant increase in the VDanat/VTexp ratio at f = 30, while VDc/VTexp and VDlav/VTexp were unchanged at both frequencies. With regional ventilation and perfusion within the obstructed pulmonary field were reduced, compared to the values at f = 10.3 cycles/min. With Cvent 20 ml/kPa, the tidal volumes were insufflated in a shorter time and with a higher initial tracheal peak pressure than with Cvent 80 ml/kPa. Following bronchial obstruction, VA, RQ and Pao2 were greater with Cvent 20 than with Cvent 80 ml/kPa. With Cvent 20, the ventilation of the lung bases was reduced, which was compensated for by a large increase in ventilation within the apical areas of the lungs, while gas distribution within the unobstructed areas was more evenly distributed with Cvent 80. Ventilation at Cvent 20 showed no essential advantage over Cvent 80. Only in lungs extremely difficult to ventilate and with ventilatory frequencies over 50 cycles/min could possible indications for Cvent 20 be seen.

Animals↗
PubMed1978

The volume of trapped gas: a new and sensitive test for the detection of exercise-induced bronchospasm in children.

The volume of trapped gas (VTG) was measured at the end of a nitrogen multiple breath wash out procedure in 16 asthmatic and 10 healthy children before and after exercise. When compared to conventional spirometric variables VTG was the most sensitive test for detection of exercise-induced asthma (EIA). The VTG was significantly higher before exercise in the asthmatic children and increased significantly after exercise, while it did not change in the healthy controls. The significance of changes caused by EIA increased if VTG/TLC % or VTG/VC % wer used. Salbutamol inhalation normalized the VTG in all the asthmatic children.

Adolescent↗
PubMed1978

Changes in volume of trapped gas in the lungs during provoked asthma followed by beta-2 receptor stimulation.

The volume of trapped gas (VTG) that could be mobilized by maximal breaths at the end of a nitrogen washout to 2% N2 was measured in 11 subjects with a history of asthma before and after provocation with specific allergens. The change after salbutamol was also measured. VTG was found to be more specific and sensitive for demonstrating early bronchospasm than changes in FEV1, VC or nitrogen washout. Salbutamol relieved all symptoms of bronchospasm.

Adult↗