Can an anesthesia machine flush valve provide for effective jet ventilation?
Transtracheal jet ventilation (TTJV) using a percutaneously inserted intravenous (IV) catheter for the patient who cannot be ventilated or tracheally intubated or, using a jet stylet for changing endotracheal tubes (ETT) in patients for whom subsequent ventilation and/or tracheal reintubation may be difficult, are extremely valuable therapeutic options. The jet ventilation system must have a sufficiently high pressure-oxygen source to drive oxygen through noncompliant tubing and through relatively small IV catheters and/or jet stylets in order to achieve adequate ventilation and oxygenation. There is no evidence that using the common gas outlet of an anesthesia machine by activating the flush valve can provide enough flow (V) and tidal volume (VT) for effective jet ventilation. This in vitro study utilized a mechanical lung model that had a varying lung compliance [Cset (10-100 mL/cm H2O)] to determine the VT (measured by integrating a pneumotachograph flow signal) and corresponding minute ventilation (VE) through 14-, 16-, and 18-gauge IV catheters and small, medium, and large jet stylets. The flow of O2 was generated by activating the flush valve of Dräger Narkomed 2 and 2A and Ohmeda Modulus II and II Plus anesthesia machines at an inspiratory:expiratory (I:E) ratio = 1:1 (unit of time = 1 s). We found that the largest VT and resultant VE were consistently obtained by activating the flush valve of the Ohmeda Modulus II and Dräger Narkomed 2 anesthesia machines. The smallest VT and VE were produced using the Ohmeda Modulus II Plus anesthesia machine.(ABSTRACT TRUNCATED AT 250 WORDS)
Gaughan
S D
SD
School of Medicine, Department of Anesthesiology, University of California at San Diego.
Benumof
J L
JL
Ozaki
G T
GT
D000758:Anesthesia / Q000379:methods; D000776:Anesthesiology / Q000295:instrumentation*; D002404:Catheterization; D006611:High-Frequency Jet Ventilation; D006801:Humans; D008168:Lung / Q000502:physiology; D008176:Lung Volume Measurements; D008954:Models, Biological