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Biomedical subjects

R Tufano

Publications and source records attributed to R Tufano.

At least 55 records · Page 3Linked to original sources
PubMed1999

Aspiration of dead space allows normocapnic ventilation at low tidal volumes in man.

OBJECTIVE: Aspiration of dead space (ASPIDS) improves carbon dioxide (CO2) elimination by replacing dead space air rich in CO2 with fresh gas during expiration. The hypothesis was that ASPIDS allows normocapnia to be maintained at low tidal volumes (VT). DESIGN: Prospective study. SETTING: Adult intensive care unit in a university hospital. PATIENTS: Seven patients ventilated for neurological reasons were studied. All patients were clinically and haemodynamically stable and monitored according to clinical needs. INTERVENTIONS: ASPIDS implies that, during expiration, gas is aspirated through a catheter inserted in the tracheal tube. Simultaneously, a compensatory flow of fresh gas is injected into the inspiratory line. ASPIDS was achieved with a computer/ventilator system controlling two solenoid valves for aspiration and injection. RESULTS: At the basal respiratory rate of 12.6 breaths min-1, with ASPIDS VT decreased from 602 to 456 ml, as did the airway pressures to a corresponding degree. PaCO2 and PaO2 remained stable. At a frequency of 20 breaths min-1, with ASPIDS VT was further reduced to 305 ml with preserved normocapnia. ASPIDS did not interfere with the positive end-expiratory pressure (PEEP) level. No intrinsic PEEP developed. All patients remained stable. No haemodynamic or other side effects of ASPIDS were noticed. CONCLUSION: The results of this study suggest that ASPIDS may be a useful and safe modality of mechanical ventilation that limits alveolar pressure and minute ventilation requirements while keeping PaCO2 constant.

Adult↗
PubMed1998

Cardiotoxicity of doxorubicin: effects of 21-aminosteroids.

The purposes of this study were to investigate in vivo the effects of two lazaroids,U-74389G (21-[4-(2,6-di-1-pyrrolidinyl-4-pyrimidinyl)-1-piperazinyl]-pregna-1,4,9 (11)-triene-3,20-dione (2)-2-butenenedionate) and U-83836E (-)-2-[[4-(2,6-di-1-pyrrlidinyl-4-pyrimidinyl)-1-piperazinyl]methy l]-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-6-ol, dihydrochloride against the cardiotoxicity induced by doxorubicin in rat and the mechanisms underlying such a toxicity. Doxorubicin (DXR) administered intraperitoneally (5 mg/kg 4 times per week for 1 week) induced significant decrease of body weight, ECG alterations and 100% mortality. The lazaroids used in this study did not protect from DXR-induced cardiotoxicity. Our results showed that the compound U-74389G delayed, but did not reduce DXR-induced mortality, and did not prevent body weight loss and ECG changes. The compound U-83836E was unable to modify any toxic effects induced by DXR. These data indicate that oxygen free radicals and the subsequent increase in intracellular calcium are only steps of DXR progressive general toxicity that leads to cardiac injury. In conclusion, we propose that the 21-aminosteroids, potent inhibitors of membrane lipid peroxidation, alone are not enough to protect from DXR toxic effects.

Animals↗
PubMed1998

Multicenter trial comparing tramadol and morphine for pain after abdominal surgery.

Seventy patients (40 male, 30 female), mean (SD) age 60.8 +/- 13.7 years were treated with parenteral morphine (10 mg/1 ml ampul) or tramadol (100 mg/2 ml ampul) to verify their analgesic effects in pain following abdominal surgery. The multicenter trial followed an open, controlled experimental design between patients, randomized within the centers. The drugs were given by intramuscular injection, as requested by patients, starting in the postoperative period when pain was more than 70 mm, assessed on a visual analog scale. Patients were allowed up to six ampuls of tramadol or morphine in the 24-h trial but in the first 4 h, if they asked for supplementary analgesic, only diclofenac (75 mg in a 3-ml ampul) was allowed. Both test drugs gave rapid and constant pain relief. After the first dose, pain intensity was reduced 36.2% with tramadol, and 51% with morphine; the pain-free interval was similar for both treatments. The quality of sleep and the number of hours of sleep the night after surgery were similar for both groups. Tramadol was tolerated better, giving rise to no untoward reactions; with morphine there was one case of mild respiratory depression. In abdominal surgery, therefore, tramadol given by intramuscular injection has postoperative analgesic activity similar to morphine, but is better tolerated.

Abdominal Pain↗
PubMed1998

[Evaluation of continuous measurement of cardiac output with thermodilution in critical patients].

BACKGROUND: A new pulmonary artery catheter and monitor for continuous cardiac output measurement (CCO), based on thermodilution principle, has been recently developed. Aim of our study was to evaluate the new system by comparing data obtained with the CCO with the standard bolus thermodilution method (TD). METHODS: Nineteen patients admitted in a medical intensive care unit were studied. In each patient 6 daily measurements of cardiac output (CO) were recorded using both the CCO and the TD. The parallel monitoring was continued for 48 h; 12 pair determinations were obtained in each patient with a total of 228. RESULTS: Total CO ranged from 2.6 L/min to 10.6 L/min. The regression coefficient was 0.94. The bias of all measurements was 0.03 (SD: +1.22-1.16). The mean relative error was 1.52% +/- 29.9. Modifications in temperature or variations in heart rate did not change the agreement between the two techniques. CONCLUSIONS: Our results confirm that CCO, although does not have all the characteristics of an ideal monitoring system, can be considered extremely useful and safe.

Adult↗
PubMed1997

Effects of ventilation in ventral decubitus position on respiratory mechanics in adult respiratory distress syndrome.

OBJECTIVE: To assess the potential benefits of a period of ventilation in ventral decubitus (VD) on oxygenation and respiratory mechanics in the adult respiratory distress syndrome (ARDS). DESIGN: In a stable condition during baseline ventilation in dorsal decubitus (DD), after 15 min of ventilation in VD and after 10 min of restored DD, the following parameters were studied: arterial blood gas tension, haemodynamics and static respiratory compliance (Crs), evaluated with the rapid airway occlusion technique. SETTING: The study was completed in the intensive care units of university hospitals as part of the management of the patients studied. PATIENTS: Twelve patients (7 males, 5 females, mean age 51.8 +/- 16.6 years) suffering from ARDS of different aetiologies. INTERVENTIONS: Before and during each evaluation, the patients were kept under stable haemodynamic and metabolic conditions. The ventilatory setting was kept constant. All the patients were sedated, paralysed and mechanically ventilated. RESULTS: A statistically significant increase in the ratio between the arterial partial pressure of oxygen and fractional inspired oxygen (p < 0.01) was observed between the baseline conditions (mean 123.9 +/- 22.6) and VD (mean 153.0 +/- 16.9), while no statistical significant was noted between baseline conditions and after 10 min of restored DD (mean 141.1 +/- 19.7). A significant increase in Crs (p < 0.001) was observed between baseline conditions (mean 42 +/- 10.1) and VD (mean 48.8 +/- 9.6) and between baseline conditions and restored DD (mean 44.7 +/- 10.6). Two patients were considered nonresponders. All the patients were haemodynamically stable. No side effects were noted. CONCLUSIONS: We observed an increase in oxygenation and Crs when the patients were turned from the supine to the prone position with the upper thorax and pelvis supported.

Adult↗
PubMed1995

Survival to lipopolysaccharide, cytokine release and phagocyte functions in mice treated with different total parenteral nutrition regimens.

Effects on host defenses of Total Parenteral Nutrition (TPN) with long- (LCT) and medium-chain triglycerides (MCT) were studied. Survival to lipopolysaccharide (LPS) challenge, blood clearance of Escherichia coli, in vivo and in vitro production of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were investigated. In BALB/c mice, LCTs produced a 25% reduction in mortality, compared with controls. TPN performed with a LCT plus MCT mixture reduced mortality by 50%. Spasms appeared after 18 h and 12 h respectively in mice treated with LCT-MCT mixture or LCTs alone, respect to controls (8 h). The LCT-MCT mixture produced a 67% blood clearance of E. coli after 1 h, while the treatment with LCTs alone had no significant effects compared to controls (about 40%). The LCT-MCT mixture induced a 50% increase in chemiluminescence respect to controls. A 33% increase was observed in rats treated with LCTs alone. TNF-alpha serum levels after challenge with LPS were not modified by any of the triglycerides or their combinations. IL-6 increased by 43% with LCT-MCT mixture and by 39% with LCTs alone versus controls. After a 3 h in vitro treatment with LCTs, human monocytes were stimulated to release TNF-alpha at levels higher than those stimulated with the LCT-MCT mixture, and respect to controls. In contrast after 3 h the stimulation with LCT-MCT mixture induced a higher IL-6 release than controls and cells stimulated with LCTs alone, or with LPS.

Animals↗
PubMed1994

Nutritional support for the patient with chronic obstructive pulmonary disease.

Malnutrition is reported in a significant percentage of COPD patients, and it may contribute to the onset of acute respiratory failure. Weight loss is due to the decrease of caloric support caused by breathlessness, digestive alterations due to hypoxemia and to the increase of energy expenditures caused by increased baseline requirements and diet induced thermogenesis (DIT). Malnutrition limits the ability to produce surfactant, leads to reduced protein synthesis, reduces cell mediated immune responses raising the patient's susceptibility to lung infection and affects the functioning of peripheral and respiratory muscles. The combination of malnutrition and COPD has devastating effects. Nutritional support is, therefore, an important part of therapy for the stable COPD outpatients, for hospital COPD patients and for ICU COPD patients. The nutritional program should follow an assessment of the nutritional status. With a correct number of calories and a correct composition of nutrients, it is possible to help these patients in the different clinical stages of the disease.

Humans↗
PubMed1992

Anesthetic agents induce human mononuclear leucocytes to release cytokines.

Studies were carried out on the ability of some anesthetic agents (Propofol, Dormicum, Ketalar and Penthotal) to induce the release of cytokines by human monocytes and lymphocytes in vitro. All anesthetic agents tested at hematic concentrations reached during anesthetic administration cause an increase in the production of Tumor necrosis factor (TNF) from human monocytes; the increase is 4-5 times greater than controls. The greatest Interleukin -1 alpha (IL-1 alpha) production increase was induced by Propofol. The release of Interleukin -6 (IL-6) is notably increased by Ketalar (about 10 times greater than controls). In the presence of different anesthetic agents, human lymphocytes release Interleukin -4 (IL-4) and Interferon gamma- (IFN-gamma). Penthotal and Ketalar increase IL-4 production which appears quite high compared to that obtained with Con A used as standard challenge. Propofol induce IL-4 release which is about the same as that seen with Con A. IFN-gamma is released in high quantities by lymphocytes treated with Propofol. Dormicum, Ketalar and Penthotal induce non-significant increase of IFN-gamma release. The results concern the choice of anesthetic, in relation to its action on host immune response. This aspect is particularly interesting in immunocompromised host.

Anesthetics↗
PubMed1992

[Usefulness of the prevention of oxygen radical damage in the critical patient using the parenteral administration of reduced glutathione in high doses].

A hyperproduction of Oxygen Free Radicals (FRO) is frequently observed during stress, anoxia, hyperbarism and may worsen the clinical conditions of intensive care patients. The hyperproduction of FRO may be reduced by antioxidants. The glutathione (GSH) is frequently associated with organic antioxidant protective systems. Forty patients receiving a continuous infusion of 70 mg/Kg/die of GSH were compared with forty patients not receiving GSH; the patients in both groups were randomized for age, sex, and pathology. Some parameters which are indirect indexes of FRO hyperproduction were chosen: ethane in the expired air, plasma malondialdehyde, fibrinopeptide A and C5 activated complement fraction, also the erythrocyte membrane deformability was investigated. The results obtained in the group receiving GSH were compared with the control group and a significative difference was found indicating a reduced FRO production. These interesting results need more trials in order to confirm a real GSH involvement in the antioxidant organic protection. In any case the supplementation with antioxidants in the therapy of intensive care patients can be regarded as an interesting means to improve their clinical conditions.

Adolescent↗
PubMed1992

[The physiopathology of oxygen venous saturation].

The paper underlines the importance of continuous SvO2 monitoring by means of the insertion of a modified Swan-Ganz optic fibre catheter into the pulmonary artery. Following an analysis of the factors which regulate O2 transport and ATP formation, together with metabolism self-regulating mechanisms which intervene in periods of stress to guarantee cellular metabolic activity, the Authors underline the importance of SvO2 as an indicator of the balance between O2 demand and supply. Real-time SvO2 monitoring is therefore considered a valuable and early marker of rapidly degenerating biological processes in critical patients.

Catheterization, Swan-Ganz↗
PubMed1990

[Anesthesia, awareness and wakefulness].

Drugs used in anesthesia do not always produce the expected neurophysiological results. By studying those cases in which the reappearance of intraoperative awareness is most common, an attempt was made to estimate how many and which levels of cerebral function could be identified. Four levels were recognised: awareness with or without memory, and wakefulness with or without dreams. These conditions are related to greater or lesser cortical activity. They can be identified using Tunstall's technique and by carefully interviewing the patient immediately after the operation.

Adult↗