Waveform of the Week: “Golden Moment”

Image 1: Screen of the FLOWi anesthesia delivery system, showing the "Golden Moment" highlighted with blue circle.

It has been over a year since writing a waveform of the week post; however I have incorporated ventilator waveform pictures in recent posts. The waveform for this week is termed the “Golden Moment”

Decreasing Dyspnea during Mechanical Ventilation

Flow Mismatch Associated with VC-CMV

Utilizing Volume Control-Continuous Mandatory Ventilation (VC-CMV) may lead to patient ventilator asynchrony [1] and dyspnea. The main reason for these issues is the fixed (constant) flow rate associated with VC-CMV.

Automatic Setting of T-Low during Airway Pressure Release Ventilation: Is it Beneficial?

http://www.draeger.com/UK/en/products/medical_ventilation/adult_icu_ventilation/rsp_evita_infinity_v500_sw2.jsp

Setting T-Low during APRV (a.k.a. Bi-Level, Bi-Vent) can be confusing and time consuming, to make it even more complicated there are three published techniques on how to set T-Low [1].

One method is setting T-Low based on the measured peak expiratory flow rate [2, 3]. The new Draeger Evita Infinity V500 ventilator allows the operator to set an “Auto-release” based on zero (0)-to- 80% of the Peak expiratory flow. This feature is nice since the operator does not have to continually assess the waveform &titrate the T-Low setting.

Conversely, this may be the least effective way to set T-Low in regards to lung protective goals, due to the inconsistent exhaled tidal volumes & auto-PEEP created with this technique [4].

Reference

[1]. Siddiqul,M. et.al.(2010). Comparison of Three Methods to Set T-Low on Airway Pressure Release Ventilation: A Model Study. Respiratory Care. 2010

[2]. Richey, S. (2009). Optimal T-Low Settings.

http://kscottrichey.blogspot.com/2009/03/optimal-t-low-settings.html

[3]. Richey, S. (2010). A Quick & Easy Way to Set T-Low During Airway Pressure Ventilation. http://kscottrichey.blogspot.com/2010/12/quick-precise-way-to-set-t-low-during.html

[4]. Richey, S. (2011). Setting T-Low During Airway Pressure Release Ventilation to Achieve Lung Protective Goals. http://kscottrichey.blogspot.com/2011/08/setting-t-low-during-airway-pressure.html