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Biomedical subjects

A Gasparetto

Publications and source records attributed to A Gasparetto.

At least 73 records · Page 4Linked to original sources
PubMed1990

Effects of the heat-moisture exchangers on dynamic hyperinflation of mechanically ventilated COPD patients.

In recent years the use of devices called Heat and Moisture Exchangers (HME) has become widespread as gas conditioners for ICU patients requiring mechanical ventilation. As an important variation of the resistive properties of the HME, related to flow and duration of use, has recently been pointed out during "in vitro" studies, the use of these devices in COPD patients could increase the levels of auto PEEP and dynamic hyperinflation. In this study we have compared the levels of auto PEEP and difference in functional residual capacity (delta FRC) in a group of COPD patients, requiring controlled mechanical ventilation (CMV), at basal conditions and after the insertion into the circuit of three HMEs (Dar Hygrobac, Pall Ultipor, Engstrom Edith) at random: the results obtained excluded a significant increase of auto PEEP and delta (FRC) both with "new" HMEs and after 12 h of continuous use.

Aged↗
PubMed1990

Auto-PEEP and dynamic hyperinflation in COPD patients during controlled mechanical ventilation and high frequency jet ventilation.

We investigated the levels of auto-PEEP and dynamic hyperinflation during high frequency jet ventilation (HFJV) and controlled mechanical ventilation (CMV) in six patients with chronic obstructive pulmonary disease within the first 36 h of acute exacerbation. The comparative evaluation was performed at similar conditions of gas exchange in HFJV and CMV: PaO2 77.6 +/- 11 mmHg vs 80.8 +/- 12 mmHg; PaCO2 46.8 +/- 2.5 mmHg vs 47 +/- 2.8 mmHg; pH 7.38 vs 7.38. In this situation, the values of auto-PEEP and dynamic hyperinflation, expressed as delta over the apneic functional residual capacity (FRC) did not differ: (auto-PEEPHFJV 8.9 +/- 3.8 cmH2O; auto-PEEPCMV 8.8 +/- 4.7 cmH2O; delta FRCHFJV 0.56 +/- 0.19 l; delta FRCCMV 0.54 +/- 0.2 l). This result suggests that, with a suitable machine setting and similar gas exchanges, HFJV produces the same level of auto-PEEP and dynamic hyperinflation as CMV in patients with chronic obstructive pulmonary disease.

Aged↗
PubMed1990

[Hemodynamic and respiratory aspects in orthotopic liver transplantation].

Intraoperative hemodynamic and respiratory data from one-year experience of orthotopic liver transplantation with veno-venous bypass (10 cases) were collected. Seven different phases of OLT was submitted to one way analysis of variance. Variability is due to degree and duration of liver disease. Basal conditions include high cardiac output with low SVRI, elevated Qs/Qt. and low oxygen consumption. Anhepatic phase shows a lower cardiac index due to reduction in ventricular performance too. The functioning graft raises body oxygen consumption above baseline. Last phases show diminution of MAP and LVSWI and a normal Qs/Qt.

Adult↗
PubMed1989

Differential evaluation of bronchoalveolar lavage cells and leukotrienes in unilateral acute lung injury and ARDS patients.

Patients with unilateral acute lung injury (UALI; n = 6) and ARDS (n = 4) were evaluated by bronchoalveolar lavage, as controls we used 5 patients suffering from cerebral hemorrhage and without pulmonary, cardiac or infectious disease who were mechanically ventilated. For each group of patients two independent bronchoalveolar lavages (BAL) were performed. The BAL fluid recovered from the two lungs was immediately analyzed for leukotrienes (LTS) by means of RP-HPLC and stained for cell counts. The BAL from the control group did not show any LTS and the percentage of neutrophils was within the normal range: 1 +/- 0.2% right lung and 1.2 +/- 0.4% left lung. The BAL fluid from UALI patients showed two different patterns, the injured lung showed high levels of LTS (39.1 +/- 8 ng ml-1 LTB4; 25 +/- 6 ng ml-1 LTD4 and 27.8 +/- 8.2 ng ml-1 11-trans LTC4) and an increased percentage of neutrophils (74.2 +/- 7%) compared to controls. Only 2 out of the 6 patients from the UALI group showed small amounts of LTB4 (4 ng ml-1) and LTD4 (3.2 ng ml-1). The BAL obtained from the "healthy lung" in both cases showed values of LTS almost eight fold lower than those present in the injured lung. The percentage of neutrophils from the unaffected lungs (4.3 +/- 7%) was not significantly different from controls. Lavage fluid from ARDS patients showed a similar picture to that of the affected lung from UALI patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Pressure support ventilation (PSV) reverses hyperinflation induced isorhythmic A-V dissociation.

We report a case of hyperinflation induced isorythmic atrio-ventricular dissociation with circulatory failure in a patient with chronic obstructive pulmonary disease. The arrythmia was successfully treated by applying "pressure support ventilation" (PSV: 20 cmH2O) which, by decreasing the respiratory rate and increasing the expiratory time reduced the level of auto-PEEP. In order to explain this result the Authors recorded, in the same patient, the level of auto-PEEP and delta FRC obtained with Intermittent Positive Pressure Ventilation (IPPV), Intermittent Mandatory Ventilation (IMV) and PSV at the same gas exchange values. PSV showed a dramatic reduction of both these parameters. (Auto-PEEP: IPPV 12 cmH2O, IMV 17 cmH2O, PSV 7 cmH2O).

Aged↗
PubMed1988

High frequency jet ventilation (HFJV) has no better haemodynamic tolerance than controlled mechanical ventilation (CMV) in cardiogenic shock.

Six patients with acute myocardial infarction (AMI) complicated by cardiogenic shock were studied in order to compare the haemodynamic tolerance of controlled mechanical ventilation (CMV) and high frequency jet ventilation (HFJV). The comparative analysis of the two techniques was performed with the same levels of PaO2 (CMV: 101 +/- 13 mmHg; HFJV: 104.2 +/- 14 p = ns); and PaCO2 (CMV: 37 +/- 1.7; HFJV: 35.7 +/- 1.4 p = ns). In this situation the values of mean airway pressure (Paw) did not differ significantly (CMV: 13 +/- 3 cm H2O; HFJV: 12.6 +/- 3.8 cm H2O) and no statistically significant difference in haemodynamic values was observed. These results demonstrate that in patients with cardiogenic shock, there is no difference between HFJV and CMV in terms of haemodynamic tolerance. Because of the more difficult clinical management of HFJV, this technique does not seem indicated as ventilatory support in patients with cardiogenic shock states.

Aged↗
PubMed1988

Neostigmine and edrophonium as antagonists of atracurium and pancuronium.

Edrophonium 0.5 mg/kg or neostigmine 0.04 mg/kg were administered to two groups of 30 patients each for antagonism of atracurium- or pancuronium-induced neuromuscular block at 25% single twitch recovery. Neuromuscular block was studied using both single twitch and train-of-four (TOF) nerve stimulation. The times to 100% single twitch recovery were significantly more rapid for patients receiving edrophonium (P less than 0.01) in both groups (atracurium and pancuronium); the TOF ratios were similar for atracurium, but for pancuronium they were greater after neostigmine than after edrophonium, and only at 25 min were these ratios similar. It is concluded that edrophonium in a dose of 0.5 mg/kg antagonizes neuromuscular blockade induced by atracurium, as does neostigmine in a dose of 0.04 mg/kg, but the former does not consistently antagonize neuromuscular blockade induced by pancuronium even at 25% of single twitch recovery.

Adult↗
PubMed1987

Clinical use of differential continuous positive airway pressure in the treatment of unilateral acute lung injury.

In some instances of unilateral acute lung injury (ALI) refractory to conventional ventilatory support, the intact lung is still able to ensure an efficient CO2 washout, the concomitant hypoxaemia being due to the loss of volume of the injured parenchyma. In these cases, the administration of a sufficient selective continuous distending pressure by means of differential continuous positive airway pressure may restore to normal the resting volume and thus the ventilatory performance of the affected lung, contemporarily avoiding the occurrence of pulmonary and systemic barotrauma.

Adult↗
PubMed1987

Some aspects of the mitochondrial oxidative metabolism in human atrial tissue during cardiopulmonary by-pass.

Following previous research on the hypoxic cell in human circulatory shock, the present work has investigated some mitochondrial oxidative aspects in atrial biopsies taken during cardiopulmonary by-pass. Cardioplegic solution and hypothermia were administered to 10 patients and the atrial samples were collected before and after aortic clamping. The results show a cellular protective effect of cardioplegia and hypothermia on the electron-transport chain, even if the enzymes with high KmO2 appear to be more sensitive to ischaemia. The results suggest a metabolic injury rather than an oxidative damage due to the induced ischaemia, alterations to fatty-acid beta-oxidation being especially notable. Because of the unchanged oxidative capacities, the oxyradical generation and the peroxidative damage appear to be irrelevant in the ischaemic period and during the course of reperfusion. Further studies are needed to elucidate the metabolic damage and the therapeutic implications due to the induced ischaemia in the myocardial cell during the aortic clamping.

Adult↗
PubMed1987

Occurrence of a circadian rhythmicity for blood pressure in patients with circulatory shock.

Ten patients hemodynamically in shock were monitored for blood pressure along the 24-hr span while under antishock therapy. Time-qualified data were analyzed by means of the cosinor procedure. The fit of a 24-hr cosine function was able to reject the null hypothesis of amplitude = O in the majority of patients under intensive care. The blood pressure circadian rhythm was found to be independent of whether the patient was responsive or refractory to therapy. This phenomenon demonstrates that the maintenance of a blood pressure circadian rhythm is a characteristic intrinsic to hemodynamic shock even if blood pressure falls to very low values along the time scale.

Adult↗
PubMed1986

Clinical applications of independent lung ventilation with unilateral high-frequency jet ventilation (ILV-UHFJV).

Six patients with unilateral acute lung injury (ALI) were treated with a new form of ventilatory support: independent lung ventilation with unilateral high-frequency jet ventilation (ILV-UHFJV). The first three patients suffered from unilateral ALI complicated by a bronchopleural fistula (BPF); they were at first ventilated with HFJV, but remained unresponsive to treatment, showing a progressive impairment of the ventilation/perfusion ratio with a deterioration in clinical condition. After selective bronchial intubation, ILV-UHFJV was started, ventilating the healthy lung with CPPV and the contralateral with HFJV. ILV-UHFJV caused a significant improvement in alveolar gas exchange leading to a rapid fall in Qs/Qt; it was also associated with a stable haemodynamic condition throughout the duration of the treatment. Subsequently, three more patients were treated; their respiratory failure was due to a unilateral ALI without BPF, unresponsive to either HFJV or CPPV. Once again, ILV-UHFJV was followed by a dramatic improvement in respiratory function; the haemodynamics remained unchanged and it was also possible to demonstrate a rapid improvement in individual and overall lung function.

Adult↗
PubMed1986

Effects of vecuronium bromide on intracranial pressure and cerebral perfusion pressure. A preliminary report.

The effects of vecuronium 0.1 mg kg-1 on intracranial pressure, heart rate and arterial pressure were evaluated in 20 anaesthetized patients with intracranial tumours undergoing neurosurgery. Apart from a slight decrease in intracranial pressure (-4.9%; ns) which was most probably the result of a concomitant decrease (-14.9%) in central venous pressure, vecuronium 0.1 mg kg-1 was without effect on either cerebral or systemic haemodynamics.

Anesthesia, General↗
PubMed1986

Changes in the levels of coenzyme Q homologues, alpha-tocopherol and malondialdehyde in human tissue during the course of circulatory shock.

Following our previous findings on mitochondrial oxidative damage during the course of circulatory shock in human muscular tissue, in the present work we examined the pathogenic connections between the electron-transport-chain enzymic activity and the ubiquinone metabolism. The effects of the oxidative damage on the alpha-tocopherol content and malondialdehyde (MDA) levels were also studied. The results reveal an involvement of cytochrome oxidase and coenzyme Q10 in the oxidative damage due to shock; alpha-tocopherol seems to show a particularly increased antioxidant activity contemporary with the marked increase in MDA levels. These findings suggest that the significant fall in the mitochondrial oxidative capacity could generate an oxygen free-radical production with subsequent peroxidative damage of the mitochondrial inner-membrane bilayer.

Blood Pressure↗
PubMed1986

The effects of atracurium besylate (Tracrium) on intracranial pressure and cerebral perfusion pressure.

Twenty-five patients with expansive pathologic brain lesions, who were anesthetized with thiopental, nitrous oxide in oxygen, and fentanyl, and who were mechanically ventilated to ensure normocarbia, received atracurium besylate 0.6 mg/kg, intravenously. Intracranial pressure, mean arterial pressure, central venous pressure, heart rate, and end-tidal CO2 were simultaneously recorded for 5 min before and for 10 min after administration of the muscle relaxant. No statistically significant changes were observed after administration of atracurium besylate. These results suggest that atracurium besylate may be used for muscle relaxation during neurosurgical operations, despite its potential for histamine release and excitement of the central nervous system.

Adult↗
PubMed1985

Shock-induced damage to mitochondrial function and some cellular antioxidant mechanisms in humans.

The effects of circulatory shock on skeletal muscle mitochondrial oxidative activity in various substrates and cytochrome oxidase activity have been investigated using samples of muscle obtained by the needle biopsy technique from human subjects. The effect of shock on superoxide dismutase activity and glutathione content of skeletal muscle was also examined. The results show that there is a large decrease in cytochrome oxidase activity during shock and also in the capacity of the mitochondria to oxidize either succinate, or pyruvate, or palmitoyl carnitine. There is a fall in the tissue content of superoxide dismutase and in the total glutathione present. Furthermore, an increased oxidized glutathione content causes a decrease in the molar ratio of reduced to oxidized glutathione present in the muscle. These findings suggest that mitochondrial electron transport chain (ETC) oxidative damage can play a relevant role in the pathogenesis of circulatory shock and support the hypothesis of oxygen-free radical involvement in the cellular injury.

Biopsy, Needle↗
PubMed1985

Effects of L-carnitine administration on mitochondrial electron transport activity present in human muscle during circulatory shock.

Carnitine was administered to a group of patients in shock, and the activities of cytochrome oxidase and succinate cytochrome c reductase in muscle needle biopsies from these patients were compared to those activities present in a non-carnitine treated control group of patients. Carnitine seemingly exerted a significant protective action on cytochrome oxidase activity during the initial phases of shock, but not to such an extent on succinate cytochrome c reductase activities.

Carnitine↗
PubMed1984

[Midazolam as an induction agent for surgery of the anterior segment of the eye].

A new water-soluble benzodiazepine, midazolam maleate, was used at a dosage of 0.15 mg X kg-1 to induce general anaesthesia for eye surgery in 30 patients. The following parameters were measured at times C (control), t1, t2 and t3 (2, 5 and 10 min after induction): systemic arterial blood pressure, heart rate, respiratory rate, arterial blood gases and eye tone. Results showed very significant changes in acid-base balance, with an increase in PaCO2 and a significant fall in eye tone; changes in haemodynamic parameters were not significant. Midazolam therefore appeared to be a good drug to use for inducing anaesthesia in eye surgery, particularly in the elderly.

Aged↗