Radiology in the diagnosis of adult respiratory distress syndrome with special reference to pulmonary oedema--its distribution and detection.
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Humans↗
Biomedical subjects
G Wegenius
Publications and source records attributed to G Wegenius.
Pulmonary function, extravascular lung water and chest radiography in a porcine model of adult respiratory distress syndrome.
To study the pathophysiology and the value of chest radiography in the diagnosis of early adult respiratory distress syndrome spontaneously air-breathing pigs under ketamine anaesthesia were investigated. Five control animals received physiological saline and showed no notable changes in physiological or radiological data. Eleven animals were infused i.v. with E. coli endotoxin over 6 h. The pulmonary dysfunction in the endotoxin animals was characterized by an early increase in venous admixture with hypoxaemia and a peak increase in pulmonary vascular resistance at 0.5 h after start of endotoxin infusion. Subsequently there was a tendency towards a restitution to baseline physiology, but from 3 h onwards a "second wave" of pulmonary dysfunction developed in addition to an increase in extravascular lung water. No significant correlation (r = 0.44) existed between the increase in extravascular lung water and venous admixture. The increase in calculated pulmonary microvascular pressure correlated significantly (r = 0.77) with the increase in extravascular lung water. Radiographic signs of pulmonary oedema were sparse. Thus, only three of 11 animals displayed increased density on chest radiography indicative of pulmonary oedema.
Animals↗
Adult respiratory distress syndrome after renal transplantation. A case report.
A potentially lethal case of "air-borne" adult respiratory distress syndrome, most likely consequent to cytomegalovirus (CMV) pneumonitis, is described in a kidney transplant patient. It was characterized by confluent densities on both lung fields with peripheral zones of normal radiographic pattern and with one of the highest values of extravascular lung water reported in the literature, in the presence of a normal pulmonary capillary wedge pressure. When specific conservative therapy for curing a potentially lethal CMV pneumonitis after kidney transplantation fails, we suggest that transplantectomy should be considered.
Adult↗
Determinants of early adult respiratory distress syndrome. A retrospective study of 220 patients with major fractures.
The records of 220 consecutive trauma patients admitted to intensive care in the period 1974 through 1982 were reviewed in an attempt to find determinants of early adult respiratory distress syndrome (ARDS). All the patients were considered to be at risk of ARDS and had major fractures without concomitant severe injuries to brain, chest or abdomen. No patient died. ARDS developed in 27 patients (12.3%), on average in the second day post-trauma. The clinical determinants of post-traumatic ARDS were high fracture index, implying severe tissue trauma, and shock on admission. Fluid overload was not found to cause ARDS. Conventional signs of disseminated intravascular coagulation (DIC) were not predictive or diagnostic of ARDS, but were related to the transfused amount of stored blood. Chest radiography was indicative of ARDS in 21 cases, but in six it was normal despite hypoxaemia. In the cases with radiographic signs of ARDS there was generally good chronologic correspondence with hypoxaemia. Ventilation with positive end-expiratory pressure may prevent the classic radiographic picture of ARDS with alveolar densities.
Adolescent↗
Value of chest radiography in adult respiratory distress syndrome.
In a prospective investigation of 19 patients with traumatic (n = 11) and septic (n = 8) shock at risk of developing the adult respiratory distress syndrome (ARDS), serial chest films were monitored. Eight patients developed ARDS, 2 following traumatic shock and 6 following septic shock. Only 2 of these 8 patients exhibited radiographic abnormalities consisting in bilateral widespread infiltrates of the alveolar type. In the 2 patients ARDS had already developed before artificial ventilation with positive end expiratory pressure (PEEP) was instituted. In the other 6 patients, in whom ventilator treatment with PEEP was initiated prophylactically or early in the disease, the chest films remained virtually normal despite development of a marked pulmonary insufficiency. It is concluded that early ventilator treatment with PEEP counteracts the classical radiographic abnormalities of ARDS, probably by reducing alveolar oedema and atelectasis. Thus, presently, with use of early or prophylactic ventilator treatment with PEEP as a therapeutic measure against ARDS chest radiography may be of limited value in the diagnosis. However, it should be essential for early recognition of therapy requiring complications.
Adolescent↗
The value of variables of disseminated intravascular coagulation in the diagnosis of adult respiratory distress syndrome.
UNLABELLED: In an investigation on 19 patients with traumatic (n = 11) and septic (n = 8) shock, at risk of developing adult respiratory distress syndrome (ARDS), various coagulation and fibrinolysis variables and also blood gases and chest x-ray were monitored. Eight patients developed ARDS - two after traumatic shock and six following septic shock. LABORATORY FINDINGS: the conventional disseminated intravascular coagulation variables (fibrinogen, platelet counts, activated partial thromboplastin time, ethanol gelation test, thrombotest, normotest and fibrin degradation products) could not discriminate between ARDS and non-ARDS patients, but showed an essentially similar reaction pattern in these two groups. Antithrombin-III and plasminogen levels were significantly lower in patients with ARDS, while factor VIII-related antigen levels were significantly higher in ARDS than in non-ARDS patients. CLINICAL DATA: patients with septic shock run a significantly greater risk of developing ARDS (6 of 8) than those with traumatic shock (2 of 11; P less than 0.02). Furthermore, the onset of ARDS after septic shock seems to occur in a more rapid way, while ARDS following traumatic shock develops more gradually. Early ventilator treatment with positive end expiratory pressure counteracts the classical radiographic picture of ARDS with bilateral alveolar densities.
Adolescent↗
Serial pulmonary angiography in rats with pulmonary damage due to intravascular coagulation.
Serial pulmonary angiography was performed in 30 rats with pulmonary damage caused by injection of a fibrinolysis inhibitor, tranexamic acid (200 mg/kg body weight injected intraperitoneally) and bovine thrombin (500 NIH/kg body weight injected into the right atrium or ventricle). The degree of inhomogeneity of the capillary phase was graded and compared with that in a group of normal rats. Changes in the capillary phase were well correlated to other signs of lung trauma, namely increase in lung weight and microscopic occurrence of interstitial and alveolar oedema and of intravascular fibrin deposits. Increased lung weight similarly was found to be well correlated to increased interstitial oedema. It had also a distinct relationship to increased inhomogeneity of the capillary phase. The disturbance of the capillary phase may have been caused by mechanical blockage due to intravascular coagulation with microembolism, and interstitial oedema, vasospasm of precapillary arteries, or by arteriovenous shunting. Inhomogeneity of the capillary phase is consistent with a gross change in the ventilation/perfusion ratio, which could explain arterial hypoxaemia observed in other investigations.
Angiography↗
Heart volume determination. A methodologic analysis.
A method, already in clinical use, of determining the total volume of the heart in patients in the supine position was evaluated. The reproducibility in the measurement of individual diameters and distances was good. A minor difference was noted between the results of 2 different examiners. A discrepancy in the total heart volume of 30 ml or more between 2 determinations was statistically significant, which may be a guide in the assessment of volume determinations in clinical practice.
Adolescent↗
Determinants of early adult respiratory distress syndrome with special reference to chest radiography. A retrospective analysis of 220 patients with major skeletal injuries.
The medical records of 220 consecutive patients with traumatic injuries admitted to the intensive care unit in the years 1974-1982 were scrutinised in an attempt to find radiographic signs and clinical determinants of early adult respiratory distress syndrome (ARDS). All patients included in this study were considered to run a risk of developing ARDS and had 'pure' major fractures in the sense that there were no accompanying severe brain, chest or abdominal injuries. There were no deaths in this series of patients. ARDS developed in 27 patients (12.3%), on an average on the second day of trauma. Chest radiographs of 21 of these patients showed features indicative of ARDS, whereas those of the other 6 patients were normal despite hypoxaemia. In most of the 27 patients the only radiographic manifestation of ARDS was interstitial oedema; only a minority presented with alveolar oedema in addition. In 6 patients no radiographic changes ever occurred. Ventilator treatment with positive end expiratory pressure may have prevented the pulmonary insufficiency from becoming radiographically manifest. The clinical determinants of post-traumatic ARDS were a high fracture index, based on the number and severity of fractures, implying severe trauma, and shock on admission. Fluid overload was not found to be the cause of ARDS.
Adolescent↗
Videodensitometry in rats with pulmonary damage due to microembolism.
Serial pulmonary angiography with videodensitometry was performed in 18 rats with pulmonary damage caused by administration of a fibrinolysis inhibitor, tranexamic acid (200 mg/kg body weight injected intraperitoneally) and bovine thrombin (500 NIH/kg body weight injected into the right femoral vein). The mean transit time (MTT) was calculated from videodensitometry, the observed area of interest consisting of approximately one-third of the right lung, including both central and peripheral parts. The impact of the pulmonary damage was analysed by morphologic methods and correlated to MTT. Although a pressure rise presumably occurred in the pulmonary circulation, no change in MTT was found after induction of pulmonary damage, indicating opening of actual and potential anastomoses between pulmonary arterioles and venules to serve as by-pass portions and as a safety-valve mechanism for the capillary bed and the right heart, respectively. Another explanation to unchanged MTT may be opening of resting capillary beds. Two rats with very severe pulmonary damage showed prolonged MTT. These rats may have suffered from cardiac failure.
Absorptiometry, Photon↗
Videodensitometry and chest radiography in the evaluation of pulmonary blood flow and pulmonary oedema in a porcine model of early adult respiratory distress syndrome.
The adult respiratory distress syndrome was induced in pigs (n = 11) by a continuous infusion of E. coli endotoxin in order to evaluate the use of radiographic videodensitometry and chest radiography for assessment of pulmonary circulation and pulmonary oedema. A further aim was to determine the effect of an ionic contrast medium, Urografin 60%, on extravascular lung water (EVLW). The infusion resulted in a decline in arterial oxygen tension. Mean pulmonary arterial pressure increased, and cardiac output decreased, resulting in a marked rise in pulmonary vascular resistance. EVLW increased moderately. The corresponding variables in control animals (saline infusion; n = 5) changed very little. Good correlations were found (r = 0.87-1.0) between absolute flows as measured by the thermodilution technique and relative flows as determined by videodensitometry in animals with pulmonary damage. In the endotoxin group there was a significant correlation (r = 0.75) between the change in EVLW from baseline to the final measurement (at 6 hours) and the corresponding change in radiographic density. Radiographic signs of pulmonary damage were sparse. Only 3 of 11 animals displayed increased radiographic density of the lung parenchyma indicative of pulmonary oedema. Pleural effusion developed in 4 animals. Injection of Urografin 60%, 1 ml X kg-1, caused a slight but significant decrease in EVLW. We propose that at this concentration and dosage the contrast medium acts mainly as an osmotic diuretic.
Absorptiometry, Photon↗
Computed chest tomography in rats with pulmonary damage due to microembolism.
Computed chest tomography was performed in 13 rats with pulmonary damage due to microembolism, caused by injection of thrombin (500 NIH/kg body weight) and tranexamic acid, a fibrinolytic inhibitor (200 mg/kg body weight), and in 9 control rats. The purpose of the investigation was to perform attenuation measurements at two levels of the right lung, each with three regions of interest (anterior, mid and posterior). Alterations in attenuation, compared with controls, were correlated with lung weight. Compared with controls, the attenuation was significantly increased in the anterior and posterior regions at both levels in animals with pulmonary damage, but not in the mid regions. There was a statistically significant correlation between increasing attenuation and increasing lung weight. A significant difference was found between damaged and control lungs regarding the microscopic grade of interstitial oedema, alveolar oedema and fibrin. Histograms of attenuation values in computed tomograms might be of value in detecting alveolar oedema. It is concluded that computed chest tomography is a good method for detecting pulmonary oedema at an early stage of experimental microembolism in the rat.
Animals↗