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Biomedical subjects

L Bonetti

Publications and source records attributed to L Bonetti.

13 recordsLinked to original sources
PubMed1995

Closed circuit anesthesia: preservation of the environment.

Closed circuit anesthesia must be considered as a primary contributor enabling to reduce the damaging effect of anesthetic agents on the environment. Halogenated vapors and nitrous oxide damage both the macro-environment, i.e. the earth's atmosphere layer and the micro-environment, i.e. the operating room ambience. As nitrous oxide is one of the most toxic agents, and as pure oxygen is harmful to the lungs, a technique of closed circuit anesthesia has been developed which employs oxygen/air (0.35:0.35 l/min) as a carrier of isoflurane. The safety of this oxygen-air technique of closed circuit anesthesia has been demonstrated by the greater stability of oxygen concentrations in the circuit in comparison to the more extensively used oxygen-nitrous oxide technique.

Air Pollutants, Occupational↗
PubMed1995

[Variations of esophageal temperature during general anesthesia with a low-flow circuit].

BACKGROUND: Anaesthesia drugs cause the cutaneous vasodilatation that produces core temperature lowering at the beginning of general anaesthesia; when the thermal threshold for vasoconstriction is reached the cutaneous heat losses are decreased. Furthermore, the soda lime begins to produce water and heat after 40 minutes of closed circuit ventilation. WORK HYPOTHESIS: The technique of inhalatory anaesthesia affects the thermal loss of patients after some hours of ventilation. DESIGN: Prospective randomized clinical trial. SETTING: Surgical Clinical operating theatre of the University of Florence. PATIENTS: 50 patients submited to abdominal non vascular surgery, for longer than 2 hours, with xifo-pubic cut, subdivided into two groups with the same anthropometric characters and age; the first ventilated with open system, the second with low flow circuit (fresh gas flow 700 ml/min). STATISTIC: "t" Student test; MEASURES: Lower one third oesophageal and inspiratory jaw of the circuit temperatures recorded for three hours. MAIN RESULTS: The savings of low flow anaesthesia begin to be significant in the third hour of anaesthesia. CONCLUSIONS: The thermal saving of closed circuit anaesthesia is, very probably, related to the humidifying and the warming of inspired air by soda lime reaction; the effect is more evident if cutaneous losses are reduced.

Anesthesia, General↗
PubMed1995

[Unexpected accumulation of nitrogen in a circuit during low-flow anesthesia. Presentation of two clinical cases].

The authors report two cases of unexpected nitrogen accumulation in the circuit during low flow anaesthesia with a fresh gas flow of 600 ml/min (O2:N2O = 1.1). Though the presence in the anaesthesia circuit of nitrogen eliminated by the patient is a common feature of closed circuit and low flow techniques, the magnitude and the speed of increase of inert gas concentration (compared with data from previous experiences) were highly suspicious for an external source. This was readily identified as a "mini" leak (30 ml/min of N2) from the air flowmeter, although his valve was in fully closed position. The report depicts an uncommon cause of air entry in the anaesthesia circuit and confirms the need for monitoring gases and vapours when closed circuit and low flow techniques are employed.

Anesthesia↗
PubMed1993

[Respiratory mechanics and gas exchange in anesthesia for laparoscopic cholecystectomy].

OBJECTIVE: To evaluate the influence of endoabdominal CO2 insufflation during anaesthesia for laparoscopic cholecystectomy on airway pressure, gas exchange and their relationships. DESIGN: Perspective; clinical investigation. SETTING: Operating room at a central general hospital. PATIENTS: 14 patients (3 males and 11 females) ASA 1-2, non smokers, without lung disease, scheduled for elective laparoscopic cholecystectomy. INTERVENTIONS: During balanced anaesthesia (N2O/O2, Fentanyl, Isoflurane), with fixed minute ventilation, endoperitoneal insufflation of CO2 held at constant pressure (21 cm H2O). MEASUREMENTS: Serial measurements of: Airway pressure, near-static compliance, ETCO2, CO2 minute production, blood gas analysis and derived data: P(a-A)O2, P(a-ET)CO2, Vd/Vt. MAIN RESULTS: During insufflation peak and pause pressures increased by 6 cm H2O and mean pressure; by 3 cm H2O; Compliance was reduced by 48%; PaO2 decreased evenly with time (p > 0.05) irrespective of the airway pressure. PaCO2, PECO2, VCO2 and Vd/Vt after a sharp increase stabilized at 30% (mean value) over the baseline. P(a-ET)CO2 and Vd/Vt fluctuate in the physiological range except for two short but significant changes (p > 0.05) at insufflation and desufflation time. CONCLUSIONS: Laparoscopic technique for cholecystectomy, at least in healthy patients, produces relevant changes in airway pressures but only minor modifications of gas exchange, similar to those seen during general anaesthesia. This technique can be safely used for routine operation with standard monitoring equipment.

Adult↗
PubMed1993

Low incidence of GvHD and rejection after pharmacological ex vivo modulation of bone marrow in 2-3 antigens mismatched BMT.

2-3 antigens mismatched BMT were performed on 32 children without a matched sibling donor. In the light of previous in vitro studies, which suggested a role of Vincristine and Methilprednisolone ex vivo treatment in modulating alloreactivity of T cells, bone marrow was treated with such a pharmacological cocktail before being infused. Acute GVHD 2 degrees to 4 degrees degree occurred in 46% of cases, chronic GVHD in 28%, graft failure in 13%. There was no significant difference between 2- and 3-antigens mismatched BMT as far as GVHD and graft failure are concerned.

Bone Marrow↗
PubMed1992

[Inhalation anesthesia in low-flow systems. Clinical evaluation of the kinetics of isoflurane in induction phase].

Closed circuit and low flow anaesthesia offer numerous advantages such as reduction of gas consumption, low cost, and less pollution in both the operating theatre and the environment. These procedures also offer increases in inspired gas humidity and temperature. However the time needed to attain the alveolar concentration MAC 95, is too long. Prefilling the whole circuit, the bellow and the bag with anaesthetic vapours shortens that time without overdosage.

Anesthesia, Closed-Circuit↗
PubMedDate not supplied

[The nurse educator: an experience among immigrants from developing countries].

Immigration from developing countries to Italy is a recent fact; however, it is causing different problems, even to health. Among these, tuberculosis holds a position of prominence; it is usually endemic in its original countries, but it finds good condition to become acute again in the discomfort and poverty of home countries. The purpose of the work is to test and confirm the promoting and defensive function of health in nursing profession, thanks to a health education project for immigrants which aims at reducing tuberculosis presence. The instrument used is a lesson about tuberculosis characteristics which the proposal to make the tubercular test, right instrument for a precocious diagnosis. The positive results achieved, show us the right evidence that the nurse is an educator: immigrants have also been offered the possibility to defend their health.

Developing Countries↗
PubMedDate not supplied

[Closed circuit inhalation anesthesia. Consumption and cost].

Closed circuit anaesthesia (CCA) and minimal flow anaesthesia diminish inhalatory anaesthetic consumption. Consumption of inhalatory anaesthesia was calculated using two different techniques: CCA and "non rebreathing" system. Costs were compared on the basis of the official list price. The CCA allowed for reduced consumption at lower costs. The resulting annual savings are equal to one third of the total price of the whole apparatus with its complementary monitoring and control systems.

Anesthesia, Closed-Circuit↗