Biomedical subjects

Lucio Barabesi

Publications and source records attributed to Lucio Barabesi.

3 recordsLinked to original sources

PubMed2003

Pulmonary embolism in very old patients.

BACKGROUND AND AIMS: Diagnosis of pulmonary embolism (PE) in the elderly remains difficult and is often late, although its incidence increases steadily with age. Since few studies have reported the clinical picture of this disease in very old patients, the aim of our study was to focus on clinical, instrumental and laboratory aspects in patients 75 years of age and over with suspected PE. METHODS: Symptoms, signs, risk factors for venous thromboembolic diseases, 12-lead electrocardiograms, B-mode echocardiograms, chest X-rays, leg compression venous ultrasonography, latex-assay quantitative D-dimer, and arterial blood gas analyses were collected for 96 elderly patients of 75 years and over (mean age 81.22 +/- 4.81) with suspected PE, admitted to our acute geriatric ward from 1997 to 2000. Patients were divided into two groups: 59 patients with PE (PE+) confirmed by pulmonary angiography, scintigraphic lung scan or necropsy, and 37 patients with normal lung scan or without PE at necropsy (PE-). RESULTS: Dyspnea and chest pain were the most common symptoms in both groups, but significantly more frequent in the PE+ group. Tachycardia, fever, cyanosis, and tachypnea were the most common objective signs in both groups; tachycardia and tachypnea were not significantly different between the two groups. Bed rest, venous insufficiency and leg deep vein thrombosis were the most common venous risk factors in PE+ and significantly different with respect to PE-. Sinus tachycardia, ST-T abnormalities and right bundle branch block were the most common electrocardiographic aspects in PE+; echocardiograms showed significantly more frequent acute involvement of right heart in PE+, whereas chest X-rays were rarely compatible with PE and did not reveal differences between the two groups. D-Dimer was significantly higher in PE+ but was below 500 ng/mL only in 25% of cases in PE-. More severe hypoxemla, oxy-hemoglobin hyposaturation and increased alveolar-arterial oxygen gradients were found at arterial blood gas analysis in PE+. CONCLUSIONS: Although many analyzed clinical, instrumental and laboratory aspects were significantly more frequent in the PE+ group, they were all non-specific and not conclusive for diagnosis of PE. Our retrospective study focus may add information about the picture and diagnostic difficulties of PE in very old patients.

Age Factors↗

PubMed2002

Extrathoracic cannulation of the left common carotid artery in thoracic aorta operations through a left thoracotomy: preliminary experience in 26 patients.

BACKGROUND: In aortic operations performed through a left thoracotomy, which require total bypass and deep hypothermic circulatory arrest, femoral artery cannulation is commonly used for arterial perfusion. This route limits the time of safe circulatory arrest and is associated with the risks of retrograde embolization or, in the case of aortic dissection, malperfusion of the vital organs. To overcome these problems, we have used cannulation of the extrathoracic left common carotid artery to ensure a central a route of arterial perfusion in these operations. The preliminary results are presented. METHODS: Between December 1999 and April 2001, we used left common carotid artery cannulation in 26 operations on the thoracic aorta performed through a posterolateral thoracotomy with an open technique during deep hypothermic circulatory arrest. Institutional review board approval and informed consent were obtained. The indications included perforating atherosclerotic ulcer (n = 5), chronic aortic aneurysm (n = 9), acute type B aortic dissection (n = 3), and chronic dissection of the thoracic aorta (n = 9). Transcranial Doppler ultrasonographic monitoring of both the right and left middle cerebral arteries was used to assess the adequacy of cerebral bihemispheric perfusion and to determine the differences in blood flow velocities throughout the procedure. RESULTS: Left common carotid artery cannulation was successful in all patients. All patients awoke from the operation, and none had cerebrovascular accidents. None died in the hospital, and complications related to carotid artery cannulation were not observed. None of the patients experienced postoperative paraplegia. In all patients transcranial Doppler monitoring indicated the absence of cerebral embolic phenomena throughout the entire procedure. Significant differences in middle cerebral artery flow velocities were observed at different phases of the procedures and between the right and left middle cerebral arteries during carotid cannulation and during selective cerebral perfusion. Nevertheless, the maximal drop of right middle cerebral artery blood velocity during selective perfusion through the left common carotid artery was within 50% of the left middle cerebral artery velocity, indicating adequate bihemispheric perfusion. CONCLUSIONS: In patients undergoing aortic operations through a left thoracotomy, extrathoracic left common carotid artery cannulation was a safe and effective means of providing proximal arterial inflow during cardiopulmonary bypass, which can be used to selectively perfuse the brain, as well as to prevent embolic phenomena in the arch vessels.

Adult↗

PubMed2002

Ranked set sampling for replicated sampling designs.

In practical ecological sampling studies, a certain design (such as plot sampling or line-intercept sampling) is usually replicated more than once. For each replication, the Horvitz-Thompson estimation of the objective parameter is considered. Finally, an overall estimator is achieved by averaging the single Horvitz-Thompson estimators. Because the design replications are drawn independently and under the same conditions, the overall estimator is simply the sample mean of the Horvitz-Thompson estimators under simple random sampling. This procedure may be wisely improved by using ranked set sampling. Hence, we propose the replicated protocol under ranked set sampling, which gives rise to a more accurate estimation than the replicated protocol under simple random sampling.

Animals↗