Abstract | BACKGROUND: Closed system suctioning, CSS, has been advocated to avoid alveolar collapse. However, ventilator manufacturers indicate that extreme negative pressure levels can be obtained during closed system suctioning, impeding the performance of the ventilator. METHODS: Suctioning with a 12 or 14 Fr catheter with a vacuum level of -50 kPa was either performed with an open technology or a CSS, where the catheter is introduced through a tight-fitting connection through the endotracheal tube, EYT. The lung model was ventilated with a Servo 900C or 300 ventilator with an I:E ratio of 1:2, 1:1 and 2:1 and extrinsic positive end-expiratory pressure (PEEP) at 0 or 10 cm H20. Respiratory volumes and alveolar pressure were measured at the lung model alveolus. RESULTS: The initial suctioning flow was >40 l/min with a 14 Fr catheter. When inserting the catheter through a no. 7 ETT, PEEP rose from 11 to 23 cm H2O during volume control ventilation with an I:E ratio 1:1. During suctioning the alveolar pressure fell to 10 cm H2O below the set PEEP level. CSS during pressure control ventilation had fewer effects. Low tidal volumes, inverse I:E ratio and secretions in the tube resulted in pressures down to -92 cm H2O. CONCLUSION:
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Authors | O Stenqvist, S Lindgren, S Kárason, S Söndergaard, S Lundin |
Journal | Acta anaesthesiologica Scandinavica
(Acta Anaesthesiol Scand)
Vol. 45
Issue 2
Pg. 167-72
(Feb 2001)
ISSN: 0001-5172 [Print] England |
PMID | 11167161
(Publication Type: Journal Article)
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Topics |
- Air Pressure
- Humans
- Lung
(physiology)
- Models, Anatomic
- Positive-Pressure Respiration
- Suction
(adverse effects, instrumentation)
- Ventilators, Mechanical
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