PubMed Health⌕ Search

Biomedical subjects

L Gattinoni

Publications and source records attributed to L Gattinoni.

At least 19 recordsLinked to original sources
PubMed1991

Body position changes redistribute lung computed-tomographic density in patients with acute respiratory failure.

Ten patients with parenchymal acute respiratory failure (ARF) underwent computed tomography (CT) scans while in the supine and prone positions. At equal levels of positive end-expiratory pressure, the authors measured the changes of CT density in dorsal and ventral basilar lung regions induced by the change of position as well as alterations of gas exchange. The level of venous admixture did not change with body position. The CT scan image of each lung was fractionated into ten levels from dorsal to ventral, each constituting 10% of the lung height. After measuring each lung fraction, the volume, the average CT number, its frequency distribution, and the expected normal value, we computed the lung tissue mass, the excess tissue mass, and the fraction of normally inflated tissue (excess tissue mass = amount of "tissue," which includes edema, cells, and blood in excess of the expected normal value). We also estimated the superimposed hydrostatic pressure on each lung region. We found that the excess lung tissue mass is independent of position. However, in patients in the supine position, lung CT density increased and regional inflation decreased from ventral to dorsal, suggesting progressive deflation of gas-containing alveoli along the gravity gradient. A similar ventral-dorsal deflation pattern occurred within 10 min in patients in the prone position. We conclude that the lung in patients with ARF behaves like an elastic body with a diffusely increased mass; dependent lung regions are compressed by the pressure of overlying structures.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1991

The value of portable chest roentgenography in adult respiratory distress syndrome. Comparison with computed tomography.

In 17 patients with adult respiratory distress syndrome, we used data derived from computed tomographic (CT) scan densitometric analysis to validate the value of portable chest roentgenograms in objectively estimating the amount of pulmonary edema. Chest roentgenograms and CT scans were taken in the same ventilatory conditions (apnea at 10 cm H2O of positive end-expiratory pressure [PEEP]); blood gas samples and hemodynamic parameters were collected at the same time. Roentgenographic analysis was undertaken by independent observers using two standardized scoring systems proposed in the literature. CT scan analysis was performed using the CT number frequency distribution and the gas lung volume (measured by helium dilution technique) to estimate quantitatively the lung density, the lung weight, and the percentage of normally aerated and nonaerated tissue. Knowing the mean CT number of the pulmonary parenchyma in a group of normal subjects, we also inferred the ideal lung weight expected in the study population and computed the excess tissue mass as the difference between actual and ideal lung weight. Both the roentgenographic scoring systems showed direct correlation with the pulmonary impairment as detected by CT scan densitometric analysis (CT number, percentage of nonaerated tissue, lung weight, and excess tissue mass; p less than 0.01) and inverse relation with the percentage of normally aerated tissue (p less than 0.01). We also found a relationship between roentgenographic scores and the impairment in gas exchange as detected by shunt fraction (p less than 0.05). We conclude that standardized reading of portable chest roentgenograms by means of scoring tables is a valuable tool in estimating the amount of pulmonary edema in a patient with adult respiratory distress syndrome.

Absorptiometry, Photon↗
PubMed1990

Physiopathology and management of coagulation during long-term extracorporeal respiratory assistance.

Thrombohemorrhagic risk is one of the main limiting factors in extracorporeal circulation. We describe here our experience in managing some life-threatening hematological complications in 58 patients with acute respiratory failure treated with long-term extracorporeal assistance. These patients were studied by clinical and laboratory means to assess questions related to heparin monitoring, coagulation complications and bleeding incidence. We found that two clotting tests, activated partial thromboplastin time (APTT) and activated clotting time (ACT) can be easily used to assess the safety of anticoagulant treatment (therapeutic ranges: APTT from 55 to 95 sec and ACT from 170 to 220 sec). A certain degree of coagulation activation, despite heparin, was indicated by the constant finding of thrombin-antithrombin complexes, while fibrinolytic activation, measured as plasminogen activator activity, was confined to the time of bypass connection and was of no clinical consequence. Platelet function was always impaired without relation to the platelet loss. Disseminated intravascular coagulation (DIC) (13 episodes) and severe bleeding (11 episodes) were major complications. DIC was corrected with a good outcome for 8 of 13 patients, while severe bleeding was correlated with a poor outcome in 8 of the 11 patients, probably because of the severity of the underlying disease.

Adolescent↗
PubMed1989

[Quantitative analysis of the lung CT in normal subjects and in patients with noncardiac pulmonary edema].

A quantitative analysis was performed of the CT images relative to 7 normal human subjects and to 22 patients affected with ARF (Acute Respiratory Failure). The CT scanner image quality was investigated, and the unit was checked with quality control procedures, in order to assure reliability and reproducibility. In every patient the lung was scanned at 3 different levels--basis, hilum and apex. The frequency distribution of CT numbers was studied. The lung areas were calculated for the different conditions, and the data correlated with functional lung data. A method was then tested to evaluate lung weight; the data obtained did not differ from literature data. All the patients were treated with different positive and expiratory pressure (PEEP). For different PEEP values, the quantitative data from CT analysis were correlated with morphofunctional indices.

Adult↗
PubMed1988

Relationships between lung computed tomographic density, gas exchange, and PEEP in acute respiratory failure.

Twenty-two patients with acute respiratory failure underwent lung computed tomography (CT) and physiological measurements at 5, 10, and 15 cm H2O positive end-expiratory pressure (PEEP) to investigate the relationship between morphology and function. Lung densities were primarily concentrated in the dependent regions. From the frequency distribution of CT numbers (difference in x-ray attenuation between water and lung) and lung gas volume measurements the authors obtained a quantitative estimate of normally inflated, poorly inflated, and non-inflated lung tissue weight. This estimated average lung weight was increased twofold above normal and excess lung weight correlated with the mean pulmonary artery pressure (P less than 0.01). Venous admixture correlated with the non-inflated tissue mass (P less than 0.01). Increasing PEEP caused progressive clearing of radiographic densities and increased the mass of normally inflated tissue (anatomic recruitment), while reducing venous admixture. The cardiac index decreased after increasing PEEP while oxygen delivery was unchanged. The authors conclude that CT scan lung density and oxygen exchange efficiency are correlated; the main effect of augmenting PEEP is to recruit perfused alveolar units that were previously collapsed.

Acute Disease↗
PubMed1988

Pulmonary microthrombosis in severe adult respiratory distress syndrome.

Pulmonary microvascular occlusive disease has been investigated using balloon occlusive pulmonary angiography in 31 patients with severe adult respiratory distress syndrome (ARDS) of different origins (14 patients with pneumonia, nine with multiple injury, eight with sepsis). Multiple pulmonary artery filling defects (PAFD) were detected in 13 (42%) patients, with a seven (78%) in nine incidence among those with posttraumatic ARDS. The presence of PAFD did not correlate with the severity of the respiratory failure, with the pulmonary hemodynamic alterations (pulmonary hypertension and increased vascular resistance), or with the final outcome (mortality rate was 54% among patients with PAFD and 61% among those with normal angiograms). These findings suggest that widespread pulmonary microthrombosis is a common event in patients with polytrauma and respiratory failure, with an important pathophysiologic role in the onset of posttraumatic ARDS.

Adolescent↗
PubMed1988

Inflammatory pulmonary edema and positive end-expiratory pressure: correlations between imaging and physiologic studies.

The anatomic and physiologic response to positive end-expiratory pressure (PEEP) was investigated using computed tomography (CT) in patients with adult respiratory distress syndrome (ARDS). The lesions (densities) in ARDS are distributed inhomogeneously but tend to concentrate in the dependent regions. The estimated lung weight (by CT scan, quantitative analysis, and lung gas volume measured with helium dilution) is, on the average, 200% higher than expected. Changing the body position from supine to prone causes a change in the density distribution in response to gravitational forces. The main effect of PEEP is to clear the densities through alveolar anatomic recruitment. Anatomic recruitment changes the mechanical characteristics of the lung and parallels the improvement in gas exchange. The effects of PEEP on pulmonary arterial pressure appear to be related to anatomic recruitment.

Humans↗