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Biomedical subjects

F Ferracci

Publications and source records attributed to F Ferracci.

29 records · Page 2Linked to original sources
PubMed1988

Testing of the Eschweiler 2500-11 blood gas analyser during inflight conditions.

Measurement of blood gas values during air transport of intensive care patients must take into account the extreme inflight variations in pressure. We tested the accuracy and reliability of the Eschweiler 2500-11 apparatus, with its incorporated pressure transducer, on four different gas mixtures equilibrated with fresh blood at two different altitudes simulated in a decompression chamber. Results for the pressure transducer show: 1) concordance of pressure values with those of ground instrumentation; 2) stable response; and 3) absence of hysteresis. Gas measurement electrodes were shown to have linear responses and were accurate for all tested values except very low PCO2 and very high PO2 figures. We conclude that the performance of this device is satisfactory during inflight conditions.

Aerospace Medicine↗
PubMed1986

Ventilatory effects of oxygen-enriched mixtures in the dog under althesin anaesthesia.

In six dogs anaesthetized with Althesin, minute ventilation, respiratory rate, tidal volume, PaO2 and PaCO2 were measured while breathing air (F/O2 = 0.21), and then after correction of hypoxaemia (F/O2 = 0.35), and again while breathing 100% oxygen (F/O2 = 1.00). The administration of 35% oxygen corrected the hypoxaemia (PaO2 = 8.98 +/- 0.76 kPa in air; PaO2 = 16.39 +/- 1.59 kPa with 35% oxygen), but produced a significant and sustained depression of ventilation. The administration of 100% oxygen induced a further significant and sustained decrease in ventilation. It is concluded that hypoxaemia is not necessary for the ventilatory depressant action of oxygen in the anaesthetized dog and that, under Althesin anaesthesia, peripheral arterial chemoreceptors are active up to high PaO2 values.

Alfaxalone Alfadolone Mixture↗
PubMed1984

[The role of metabolic acidosis in alphathesin-induced tachypnea in dogs].

In the dog anaesthetized with Althesin, tachypnea has been observed under light anaesthesia. There was also a metabolic acidosis which might be responsible for the increase of the respiratory rate. The ventilatory effects of the correction of the metabolic acidosis were studied in five dogs anaesthesized with Althesin administered at a constant rate of infusion (6.06 +/- 2.67 microliters X kg-1 X min-1). The ventilatory pattern (duration of inspiration, TI; duration of expiration, TE; duration of the respiratory cycle, Ttot; respiratory rate, f; ratio TI/Ttot, tidal volume (VT), minute ventilation (VE), mean inspiratory flow (VT/TI) and blood gases, pHa, PaCO2, PaO2, were measured before and after administration of 42 p milli sodium bicarbonate (495 mmol X l-1). Arterial pH increased from 7.27 +/- 0.10 to 7.44 +/- 0.20 (p less than 0.05). There was no statistically significant change of other values, particularly for respiratory rate which varied from 41 +/- 10.5 to 43.3 +/- 17.2 per minute. Metabolic acidosis does not explain the tachypnea. Mechanisms of tachypnea, particularly the role of histamine, are discussed.

Acidosis↗
PubMed1984

Hypoxic ventilatory drive in the dog under Althesin anaesthesia.

Althesin was administered i.v. to eight dogs, using two different rates of infusion (6.55 +/- 2.13 microliter kg-1 min and 12.80 +/- 2.00 microliter kg-1 min). Ventilation (TI, TE, RR, TI/Ttot, VT, VE, VT/TI) and arterial blood-gas tensions were measured in air and during a 10-min period of 100% oxygen breathing. For both rates of Althesin infusion the ventilatory response to oxygen was identical: there was significant depression of ventilation (decrease in VE and of the ventilatory drive, VT/TI) from the 1st min of inhalation lasting up to the 10th min. This decrease in ventilation was more marked and persistent than the decrease noticed in the unanaesthetized dog. We conclude that the hypoxic ventilatory drive persists in the dog under Althesin anaesthesia.

Alfaxalone Alfadolone Mixture↗
PubMed1983

Ventilatory effects produced by the i.v. administration of incremental doses of thiopentone in the dog.

Ventilation, ventilatory pattern and ventilatory drive were studied in five dogs during the administration of increasing blood concentrations of thiopentone. Ventilation (VE, RR, VT) and blood-gas tensions (pHa, PaCO2, PaO2,) were measured. Ventilatory pattern (VT, TI, TE, Ttot) and ventilatory drive (VT/TI) and occlusion pressure) were analysed. Occlusions of the airway were performed at end-inspiration and at end-expiration. Thiopentone produced a biphasic action on respiratory rate, ranging from tachypnoea during light anaesthesia to a progressive slowing of respiration with deepening anaesthesia. The Hering-Breuer reflex did not seem to be modified by the level of anaesthesia, whereas the central mechanisms which modulate the duration of inspiration and of expiration, were perturbed.

Anesthesia, Intravenous↗
PubMed1982

[Respiratory effects of increasing doses of alfathesin in the dog].

In 10 dogs the authors studied the effect of increasing doses of alfathesin on ventilation (VE, frequency, VT, blood gases), on the ventilatory pattern (TI, TE, TI/Ttot), on the neurological initiation of ventilation (VT/TI, occlusion pressure at 0.5 seconds), and on the Hering-Beurer reflex (duration of apnoea after occlusion of the airway at the end of inspiration). The results were compared with normal values taken from the literature. The correlation between the dose of alfathesin and the measured or calculated parameters was examined. Ventilation was stimulated by low doses of alfathesin, a stimulation, characterized by tachypnoea without change in tidal volume. Deepening of anaesthesia was accompanied by progressively increasing depression of respiration (diminution of VE, of frequency, of VT/TI and increase of PaCO2 and of the duration of apnoea). The mechanisms of the initial stimulation of ventilation and of respiratory depression are discussed. The authors conclude that the action of alfathesin on the central nervous system is biphasic, with stimulation during light anaesthesia followed by depression with associated depression of ventilation, despite increasing hypoxia and hypercapnia.

Alfaxalone Alfadolone Mixture↗
PubMed1981

[Comparison of the effects of acute respiratory acidosis and acute metabolic acidosis on the jaw-opening reflex in the anesthetized dog].

A few effects of carbon dioxide on pain threshold and acid-base balance are known. The purpose of this study was to investigate specifically the variations of analgesia in relation to hypercapnia during general anaesthesia and the respective roles played by carbon dioxide and [H+]. The nociceptive jaw opening reflex was studied on five beagle dogs anaesthetized with alfathesin administered at constant rate under acute hypercapnic conditions and acute metabolic acidosis. Acute hypercapnia did not decrease the jaw opening reflex significantly until a level was reached where PaCO2 values modified blood [H+] (pH) significantly (10 +/- 1.04 kPa corresponding to [H+] 91.5 +/- 13.24 nmol/l (pH 7.04 +/- 0.06) p less than 0.05)). At [H+] 176.2 +/- 42.77 nmol/l (pH 6.7 +/- 0.13) (p less than 0.01) the reflex was only 9.3 +/- 3.9 per cent (p less than 0.001) of its initial value. The infusion of decinormal solution of HCl during constant capnia caused an abrupt drop of the reflex. There was a correlation between reflex and metabolic acidosis (p less than 0.05). The authors conclude that modification of the jaw opening reflex occurs with extreme values of arterial [H+] incompatible with safe anaesthesia and they discuss the mechanisms involved.

Acidosis, Respiratory↗
PubMedDate not supplied

[Quadriplegia and prolonged respiratory insufficiency due to tick-borne encephalomyelitis. Case report].

Tick-borne encephalitis (TBE) is an uncommon and potentially severe illness. TBE virus is transmitted to the humans by an infected tick and it spreads to the central nervous system determining various clinical pictures. A case in which TBE virus caused an encephalomyelitis with quadriplegia and respiratory insufficiency that persist one year after the diagnosis, is reported. Such a clinical manifestation of TBE has never been described in Italy till now.

Adult↗
PubMedDate not supplied

Comparison of event related potentials (ERPs) distributions obtained with three reference systems: linked binaural, mean reference, extracephalic.

Event related potentials (ERPs) to auditory and visual oddball paradigms were recorded from 19 scalp derivations in 10 controls. Three different reference systems were used: the linked earlobes (LE), the computer calculated mean reference (MR), and a calibrated sterno-vertebral extracephalic reference (EC). The distribution of ERPs was represented on single plane maps (quadratic interpolation, 4-NN method). With LE reference N2, P3a-P3b had no polarity reverted counterparts on the scalp. With EC reference a negativity was recorded on T3-T4 (and partly T5-T5) derivations with the same latency as P3a-P3b vertex component. With MR the N2, P3a-P3b components at vertex were paralleled by polarity reverted counterparts on anterior frontal, temporal and occipital derivations.

Acoustic Stimulation↗