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F J Belda Nácher

Publications and source records attributed to F J Belda Nácher.

5 recordsLinked to original sources
PubMedDate not supplied

[Preoxygenation for anesthesia].

Oxygenation, or rather denitrogenation, prior to apnea during anesthetic induction attempts to replace alveolar nitrogen with oxygen to achieve an intrapulmonary oxygen reserve that will allow apnea to be as prolonged as possible with the least possible desaturation. During apnea, the rate of arterial desaturation depends mainly on the volume of oxygen stored in the lung, on mixed venous oxygen saturation, and on the presence of intrapulmonary shunt. Together, these factors account for the higher rate of desaturation during apnea in children, obese individuals, postoperative patients, and pregnant women. Two approaches to preoxygenation have proven effective to date: ventilation with 100% oxygen at tidal volume for 3 minutes using a well-sealed face mask and the performance of 8 vital capacity maneuvers in 1 minute. The efficacy of preoxygenation can be assessed by expired oxygen fraction or by pulse oximetry. In a healthy adult, both methods described ensure sufficient oxygenation (pulse oximetry 90% to 95%) after a period of apnea lasting between 6 and 10 minutes.

Anesthesia↗
PubMedDate not supplied

[Monitoring of mechanical ventilation during IPPV: implications due to the intrapulmonary entrapment of gas. Study on a physical model of the lung].

This work was undertaken to determine the possible influence of gas trapping on the values of total respiratory system compliance and on the air flow resistance at the air ways obtained by conventional effects of positive telespiratory alveolar pressure (auto-PEEP) typical of gas trapping on ventilatory dynamics. This study has been carried out in a physical model of the lung. The results support the contention that in the above situation: 1) the total compliance of the respiratory system measured as the quotient between the current volume and the plateau pressure (C.DIN) shows lower values than those of the static compliance (C.EST), and 2) flow resistance at the air ways must be measured as the quotient between the time constant and the plateau pressure. It should not be measured as the quotient between the time constant and the static compliance since in that case the values would be lower than the real ones.

Airway Resistance↗