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Biomedical subjects

L Martinelli

Publications and source records attributed to L Martinelli.

At least 55 records · Page 3Linked to original sources
PubMed1996

Surveillance transbronchial biopsy in the diagnosis of acute lung rejection in heart and lung and lung transplant recipients.

From March 1991 to December 1993, 30 patients underwent transbronchial biopsy (TBB) after lung transplantation (16 with a heart lung transplant, 7 with a single lung transplant, and 7 with a double lung transplant). The now standard TBB technique was used. Initially, TBB was performed only when clinically indicated, i.e. when there were sound reasons to suspect the existence of acute rejection (AR) or pulmonary infection. From 1992, all the patients were entered into a prospective study, the protocol of which called for serial "surveillance" TBB to be performed, in addition to those for clinical indications, 15 days, 2, 3, 6, 9 and 12 months after the transplant, and then annually. One hundred and twenty nine transbronchial biopsies were performed in 2.5 yrs. Of the 121 successful TBBs, 54 (45%) were positive, i.e. showed signs of acute rejection. Sixty six of 129 (51%) of the TBBs were performed because of clinical indications, 45 of them (68%) within the first 3 months following the transplant. The other 63 were surveillance biopsies. About two thirds of the clinically indicated TBBs and more than a quarter of the surveillance TBBs, yielding adequate samples, were positive for AR > or = A2 (mild rejection). The sensitivity and specificity of the method in detecting AR were 91 and 100%, respectively. The overall incidence of complications was 10.8% (pneumothorax in 9% of cases). There were no deaths correlated to the procedure. Our results confirm the decisive role of TBB in the diagnosis of acute lung rejection. The high incidence of mild acute rejection, and the occasional finding of moderate acute rejection in stable asymptomatic patients, support the use of surveillance TBB in the first 6 months.

Bronchoscopy↗
PubMed1996

Arterial-venous PCO2 gradient in early postoperative hours following myocardial revascularization.

OBJECTIVE: To investigate the utility of the arterial-venous PCO2 gradient (P(a-v)CO2) as a marker of the increased risk of postoperative complications in the early postoperative hours following myocardial revascularization. EXPERIMENTAL DESIGN: Prospective study. SETTING: The Postoperative Intensive Care Unit (ICU) of a University Hospital. PATIENTS: Thirty patients (28 males and 2 females; aged 39-70) that consecutively underwent myocardial revascularization. INTERVENTIONS: None. MEASURES: Thirty minutes following arrival at the ICU the hemodynamic parameters were recorder; the arterial and mixed venous hemogasanalyses were obtained; the mixed venous blood hemoglobin saturation (SvO2) and the O2 consumption (VO2) were calculated; and plasma lactate was determined. The arterial and mixed venous hemogasanalyses were determined again 90 minutes after the admission to the ICU. RESULTS: P(a-v)CO2 at 30 minutes was 8.1+/-2.3 mmHg and was only slightly lower at 90 minutes (7.5+/-2.3 mmHg) so that any significant influence of patient transport to the ICU could be ruled out. P(a-v)CO2 did not significantly relate with cardiac index, mixed venous blood O2 saturation, and blood lactate. Twenty-one patients (70%) showed P(a-v)CO2 values higher than 7 mmHg at 30 minutes: in comparison with the others they were characterized by higher arterial blood PCO2 (PACO2) (37+/-5 vs 32+/-3 mmHg; p<0.05) in spite of similar ventilatory variables, by higher mixed venous blood PCO2 (PVCO2) (47+/-6 vs 37+/-3 mmHg; p<0.01), and by lower cardiac index values (2.0+/-0.3 vs 2.3+/-0.6 1/min/m2; p<0.05). The patients that presented abnormally high P(a-v)CO2 values showed a higher rate of postoperative complications, including inadequate cardiac performance, cardiac arrhythmias, prolonged mechanical ventilation, increased plasma creatinine, and jaundice (11 patients out of 21 vs 1 patient out of 9; p<0.05). Finally P(a-v)CO2 was related with arterial-mixed venous O2 content difference (regarded as an index of O2 consumption), hematocrit, blood temperature and PACO2 by multiple linear regression (R=0.74; p<0.01). The coefficients of all factors but hematocrit were significant; hence, apart from the cardiac index, P(a-v)CO2 was influenced by the metabolic rate, the body temperature (possibly because of CO2 release during rewarming), and the impaired CO2 elimination through the lungs. CONCLUSIONS: P(a-v)CO2 represents a useful even if aspecific parameter to monitor patients during the early postoperative period after myocardial revascularization.

Adult↗
PubMed1996

[Lung transplantation in Pavia. Clinical experience].

Single and bilateral lung transplantation represents the most recent success in the field of organ replacement. The procedure underwent a very long period of laboratory and clinical experimentation and it is still a high-risk procedure to be performed by a few highly specialized centers. At our Department of Cardiac Surgery, the preliminary experience in lung replacement was obtained by clinically applying heart-lung transplantation in patients with both vascular and parenchymal lung disease during 1991. In the following years, the indications for isolated lung transplantation were enlarged by some centers with good results; this consideration, together with the scarce availability of integral heart-lung blocks, led us to use single and bilateral lung transplantation initially for parenchymal disease and subsequently also for vascular disease. Since February 1992, 12 single lung transplantations and 12 bilateral lung transplantations have been performed at our Center. In this report the selection criteria, the preoperative characteristics and the perioperative variables of donors and recipients are discussed. Particular emphasis is given to immunosuppression treatment, diagnosis of rejection and airways suture complications. The conclusions summarize the present indications for the different types of lung transplantations according to the different preoperative diagnosis.

Adolescent↗
PubMed1995

Successful treatment of aortic dissection after heterotopic heart transplantation.

Heterotopic heart transplantation is a valid option when there is a large donor-recipient size mismatch. However, the presence of the diseased native heart can jeopardize the medium-term and long-term outcome. The problems stemming from this most commonly described in the literature are thromboembolism, angina, and arrhythmias. In this report, we describe the case of a type A aortic dissection in the native aorta that occurred 30 months after heterotopic heart transplantation and the surgical technique successfully applied for its repair. We also discuss some of the alternative techniques.

Aortic Dissection↗
PubMed1995

Haemodynamic and metabolic effects of surface rewarming after coronary revascularization.

Cardiac surgery is often associated with a postoperative increase in the patient's metabolic rate; surface rewarming has been suggested to decrease the energy expenditure by preventing hypothermia. Thirty patients, undergoing coronary revascularization, were randomly divided into two groups; after surgery group A was rewarmed by a new device that acts by both conduction and convection, while group B was just covered with cotton blankets. Blood, oesophagus and skin (thigh and foot) temperatures were recorded on admission to the intensive care unit (ICU) and 30, 60, 90, 180, 270, and 450 min later. Haemodynamic parameters, oxygen delivery, calculated oxygen consumption, and plasma lactate concentration were assessed as well. Group A warmed up quicker than group B as far as the skin was concerned while the core temperature was unaffected. Group A was also characterized by lower cardiac indices and oxygen consumption. As the occurrence of a dependence of oxygen consumption on delivery could be reasonably ruled out in warmed patients because blood lactate levels were lower than in the controls, we conclude that surface rewarming might have some positive effect in decreasing metabolic demand after cardiac surgery even if the patient's core temperature is little affected. The inhibition of skin temperature receptors could possibly explain this finding.

Bedding and Linens↗
PubMed1995

Different results of cardiac transplantation in patients with ischemic and dilated cardiomyopathy.

We retrospectively analyzed 275 consecutive transplanted patients, dividing them into group A (128 patients) affected by ischemic cardiomyopathy and group B (147 patients) affected by dilated cardiomyopathy. The difference in demographic, clinical and hemodynamic preoperative and postoperative data between the groups was studied; group A patients presented at transplantation with a less compromised hemodynamic picture, requiring inotrope infusion and mechanical assistance less frequently. The influence of etiology on early postoperative complications was also analyzed: group A patients needed postoperative mechanical assistance, inotrope, infusion and prolonged mechanical ventilation more often, therefore requiring a longer stay in the intensive care unit (ICU). Hospital mortality was twice as high in group A. The older age of group A patients per se did not influence these results significantly. The long-term follow-up was then studied with particular attention to parenchymal functions, hemodynamics, coronary artery disease, metabolic and surgical complications, and survival. The complication rate was higher in group A, with more severe hypertension and higher cholesterol levels at 1 year, a higher prevalence of accelerated coronary artery disease (CAD) and a more frequent onset of insulin-dependent diabetes. Surgical and vascular complications were also more frequent. The final result was a better 5-year actuarial survival rate for group B patients. Donor and recipient ages at the time of transplant did not influence this result. We conclude that ischemic patients, even if they are transplanted in better condition and operated more electively, have a more critical early and long-term postoperative course and a worse survival rate. These findings are not explained by advanced age, but could be due to the impact of atherosclerosis and metabolic impairments associated with ischemic disease.

Actuarial Analysis↗
PubMed1995

The relationship between systemic oxygen uptake and delivery during moderate hypothermic cardiopulmonary bypass: critical values and effects of vasodilation by hydralazine.

The relationship between oxygen delivery (DO2) and uptake (VO2) has been studied during moderately hypothermic cardiopulmonary bypass (CPB) in 15 patients undergoing myocardial revascularization. As soon as nasopharyngeal temperature was lowered to 32 degrees C, blood flow was decreased from 2.4 to 2.0 l/min/m2. Arterial and mixed venous blood gas analyses were performed five and eight minutes later and DO2 and VO2 were calculated; VO2 stabilized in five minutes after changing blood flow and neither DO2 nor VO2 values changed three minutes later (DO2: 217 +/- 19 versus 215 +/- 17 ml/min/m2; VO2: 63 +/- 12 versus 66 +/- 14 ml/min/m2). Blood flow then was increased to 2.3 l/min/m2 and DO2 and VO2 were determined again, five minutes later; they both increased significantly, to 243 +/- 20 and 74 +/- 13 ml/min/m2, respectively. However, a further blood flow increase to 2.6 l/min/m2 which caused DO2 to increase to 277 +/- 24 ml/min/m2, did not affect VO2 which was unchanged five minutes later (76 +/- 13 ml/min/m2); VO2 dependence on DO2 values higher than 243 +/- 20 ml/min/m2 was consequently ruled out. Ten patients, having a mean arterial pressure higher than 80 mmHg, were eventually vasodilated with hydralazine, 0.1 mg/kg intravenously, and DO2 and VO2 were determined after five and ten minutes. As blood flow did not change, DO2 was unaffected while a slight increase in VO2 mean values was observed which was not statistically significant (prior to hydralazine: 78 +/- 15 ml/min/m2; five minutes later: 82 +/- 17 ml/min/m2; 10 minutes later: 76 +/- 18 ml/min/m2). In conclusion, during hypothermic CPB at 32 degrees C, VO2 plateau ranges between 48 and 102 ml/min/m2 (mean +/- 2 SD) in 95% of patients, corresponding to 66 and 141 ml/min/m2 at 37 degrees C; this finding closely matches other literature reports. Consequently, lower VO2 values suggest inadequate oxygen supply to tissues. Critical DO2 at 32 degrees C is lower than 283 ml/min/m2 in 97.5% of patients. Finally, arterial vasoconstriction does not seem to play a significant role in tissue hypoperfusion.

Adult↗
PubMed1995

Cryopreserved small-diameter arterial allografts for arterial by-pass procedures: an experimental study.

The search of small-caliber vascular prosthesis for myocardial revascularization and arterial reconstruction has led to an investigation of cryopreserved arterial allografts in a sheep model. Carotid arteries with an internal diameter of 4 mm and length of 10 cm were harvested from donor sheep and soaked immediately in a cold saline solution. Nine arteries were cryopreserved in a nutrient media containing 10% DMSO as cryoprotectant and then were stored in a liquid nitrogen vapor at -150 degrees C to -170 degrees C. In recipient sheep from different species, arterial substitution of a 10 cm segment of carotid artery was realised by implantation of fresh (n = 9) or cryopreserved (n = 9) carotid artery allografts. After 3 months, the allografts were harvested. In both groups: 7/9 were patent at the time of explantation. Components of arterial allograft rejection were observed in most fresh and cryopreserved arteries: intimal thickening with cell proliferation was seen in fresh (3/7) and cryopreserved (4/8) arteries; Loss of smooth muscle medial cells was constant; Adventitia was involved by a marked inflammatory reaction. A non cellular fibrous intimal thickening and presence of large medial calcifications were essentially observed in cryopreserved arteries. In conclusion, these results show that at three months post implantation, there is little difference in the outcome of fresh and cryopreserved arterial allografts. Cryopreservation does not reduce the apparent antigenicity of small diameter arterial allografts.

Animals↗
PubMed1995

Retained intraaortic balloon. Case report and review of the literature.

We report a case of intraaortic balloon entrapment in a 70-year-old man who underwent emergency triple coronary bypass. Intraaortic balloon rupture caused the formation of a clot inside the balloon that eventually was responsible for the balloon's entrapment at the aortic bifurcation. The patient had severe atherosclerosis of the aorta and iliac arteries. Balloon removal required aorto-iliac exposure and aorto-bifemoral bypass. After 16 months, he is symptom free and at home.

Aged↗