Lowest work of breathing and lowest force of breathing in ASV® and ASV 1.1

While both work of breathing and force of breathing focus on the respiratory time constant (RCexp) – resistance and compliance – as well as MinVol and Vd, there are small variations in the calculations.  ASV 1.1 results in higher respiratory rates for normal and restrictive patients.

For any given combination of resistance, compliance, alveolar ventilation per minute and dead space, there is a respiratory rate which uses the lowest possible energy.

ASV 1.1 uses algorithms based on the least work of breathing and the lowest force of breathing to calculate this target frequency and thus lead the patient to the most favorable breathing pattern.

ASV 1.1 is a further development of the original ASV mode, launched by Hamilton Medical in 1998, and is based on official recommendations subsequently released with respect to tidal volumes and prevention of VILI.  The main differences are increased target rates and reduced tidal volumes for the majority of patients, as well as a tidal volume limitation of 15 ml/kg IBW.

• ASV selects VT/IBW equal to current clinical practice
• ASV 1.1 selects lower VT/IBW according to the latest recommendations for ARDS and normal lung patients
• ASV 1.1 helps users to apply recommendations

ASV 1.1 is the default setting for:

• HAMILTON-G5:  SW v2.60 and above
• HAMILTON-C6:  SW v1.0.x and above
• HAMILTON-C1/T1/MR1: SW v2.2.0 and above
• HAMILTON-C3: SW v2.0.x and above
• HAMILTON-C2: not available