• Journal of Chest Surgery
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• v.10 no.2
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• pp.195-204
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• 1977

Dynamic lung compliance was measured in healthy ten young[mean age, 26 years] male and five young[mean age, 25 years] female. Lung volume was integrated of the rate of flow signal which was obtained by using pneumotachograph and differential pressure transducer[PM 5, Statham]. Intrapleural pressure was measured as that of intraesophagel pressure. Esophageal ballon, 15. 5cm in length, 4ml of luminal capacity and made of thin latex, was connected to the polyethylene tube that had 12-14 side holes and was of 1.5mm of ID. Transpulmonary pressure was traced by means of differential pressure transducer[PM 131, Statham] to which connected the esophageal balloon catheter and connection tube from mouth piece. Lung volume and transpulmonary pressure were photographed by cathode ray oscilloscope camera while the subjects were breathing spontaneously. Dynamic lung compliance loop was displayed on single trace monitor and subtraction was performed for the quasi-static hysteresis. Dynamic lung compliance was measured, 1. by plotting the pressure-volume relationship 2. from the subtracted pressure-volume loop. Results were as follows. 1. Dynamic lung compliances measured by plotting of healthy young male and female were $0.202{\pm}0.06$ and $0.190{\pm}0.023L/cm$ $H_2O$ respectively. 2. When measured from subtraction loop, dynamic lung compliance for male and female were $0.327{\pm}0.107$, and $0.27{\pm}0.06L/cm$ $H_2O$ respectively. 3. Dynamic chest wall and total respiratory system compliance were also measured. 4. Dynamic lung compliance by plotting appeared to be essentially same when compared to that of static compliance reported previously from our laboratory, however, that obtained from subtraction loop revealed higher values than the compliances obtained by plotting and that of static compliance.

• Journal of Korean Academy of Nursing
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• v.44 no.2
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• pp.149-158
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• 2014

Purpose: This study was conducted to compare effects of open and closed suctioning methods on lung dynamics (dynamic compliance, tidal volume, and airway resistance) and hypoxemia (oxygen saturation and heart rate) in mechanically ventilated patients. Methods: This study was a cross-over repeated design. Participants were 21 adult patients being treated with endotracheal intubation using a pressure-controlled ventilator below Fraction of Inspired Oxygen ($FiO_2$) 60% and PEEP $8cmH_2O$. Data were collected at baseline and 1, 2, 3, 4, 5, and 10 minutes after suctioning. Data were analyzed using two-factor ANOVA with repeated measures on time and suctioning type. Results: Effects of the interaction between suction type and time were significant for oxygen saturation and heart rate but not significant for dynamic compliance, tidal volume, or airway resistance. Prior to performance of suctioning, tidal volume and oxygen saturation were significantly lower, but airway pressure and heart rate were significantly higher using the closed suctioning method as compared with the open suctioning method. Conclusion: For patients on ventilator therapy below $FiO_2$ 60% and PEEP $8cmH_2O$, open suctioning performed after delivery of 100% $FiO_2$ using a mechanical ventilator may not have as much negative impact on lung dynamics and hypoxemia as closed suctioning.