Patient-ventilator interactions during volume-support ventilation: asynchrony and tidal volume instability--a report of three cases

Respir Care. 2001 Mar;46(3):255-62.


During pressure-support ventilation, tidal volume (V(T)) can vary according to the level of the patient's respiratory effort and modifications of the thoraco-pulmonary mechanics. To keep V(T) as constant as possible, the Siemens Servo 300 ventilator proposes an original modification of pressure-support ventilation, called volume-support ventilation (VSV). VSV is a pressure-limited mode of ventilation that uses V(T) as a feedback control: the pressure support level is continuously adjusted to deliver a preset V(T). Thus, the ventilator adapts the inspiratory pressure level, breath by breath, to changes in the patient's inspiratory effort and the mechanical thoraco-pulmonary properties. The clinician sets V(T) and respiratory frequency, and the ventilator calculates a preset minute volume. It has been shown that ineffective respiratory efforts can occur during pressure-support ventilation.

Publication types

  • Case Reports

MeSH terms

  • Female
  • Humans
  • Lung Diseases, Obstructive / physiopathology
  • Lung Diseases, Obstructive / therapy
  • Male
  • Positive-Pressure Respiration / adverse effects*
  • Positive-Pressure Respiration / methods*
  • Respiration Disorders / physiopathology
  • Respiration Disorders / therapy*
  • Tidal Volume
  • Ventilators, Mechanical