A simple, lightweight CPAP-delivery device, composed of a three-way stopcock, for the nondependent lung.
OBJECTIVE
We aimed to introduce a simple, lightweight continuous positive airway pressure (CPAP)-delivery device for the nondependent lung during one-lung ventilation, to investigate how the type of three-way stopcocks, and the compliance and resistance of a test lung affect the relationship between the oxygen flow rate and CPAP level produced, and to examine how the device works in a clinical setting.


METHODS
In the test lung study, the bronchial blocker of a Univent tube was connected to a test lung. The effects of oxygen-flow rate, types of three-way stopcocks, and compliance and resistance of the test lung on the CPAP levels were studied. In the clinical study, the lightweight device was used to treat hypoxia in seven patients during one-lung ventilation with the bronchial blocker.


RESULTS
In the test lung study, the CPAP level produced by the device was proportional to the oxygen-flow rate, dependent on the type of three-way stopcock used, and independent of the compliance or resistance of the test lung. There was no discrepancy between the plateau pressures of the test lung and the monitoring port of an additional stopcock at any degree of compliance or resistance of the test lung at any oxygen-flow rate. Therefore, the relationship between the oxygen-flow rate and CPAP level can be ensured in advance before application to the lung, with an additional three-way stopcock of which the distal end is occluded. In the clinical study, peripheral oxygen sataration Sp(O2) improved while the CPAP level ranged from 2.8 to 5.4 cmH2O.


CONCLUSIONS
The lightweight CPAP delivery-device can provide variable CPAP levels by adjusting the oxygen-flow rate without real-time monitoring of the pressure.
Sasano
Hiroshi
H
Department of Anesthesiology and Medical Crisis Management, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, 467-8622, Japan.
Sasano
Nobuko
N
Ito
Shoji
S
Azami
Takafumi
T
Morita
Masato
M
Takeuchi
Akinori
A
Sobue
Kazuya
K
D000399:Air Pressure; D000403:Airway Resistance / Q000502:physiology; D045422:Continuous Positive Airway Pressure / Q000295:instrumentation*; D006801:Humans; D008168:Lung / Q000502:physiology*; D008170:Lung Compliance / Q000502:physiology; D010100:Oxygen / Q000008:administration & dosage / Q000097:blood; D012121:Respiration, Artificial / Q000295:instrumentation*
D010100:Oxygen