In what respect does high frequency positive pressure ventilation differ from conventional ventilation?
The original rationale for HFPPV was that under certain conditions adequate alveolar ventilation could be achieved with high ventilatory frequencies and small tidal volumes. It was theorized further that increased ventilatory frequencies and low tidal volumes would decrease the airway pressures, barotrauma, and cardiovascular and other systemic consequences seen with conventional mechanical ventilation. The first clinical applications of HFPPV were in bronchoscopy and laryngoscopy for diagnostic and/or therapeutic purposes. Apart from these endoscopic applications, volume-controlled HFPPV has been compared with conventional ventilation in upper abdominal surgery and coronary artery bypass grafting. The possible advantages of HFPPV over conventional volume-controlled ventilation in the intensive care setting are still unclear. Provided that the mean lung volumes are similar, oxygenation in acute respiratory failure is similar with both ventilation methods. Although the role of HFPPV in the management of pulmonary diseases still remains to be clarified, it does provide effective ventilation in selected types of patients needing ventilatory support. New modes of pressure-controlled ventilation have not resolved all clinical problems in severe ARDS and/or acute respiratory failure. The search for means of optimal ventilatory support with minimal complications must continue, as conventional ventilation does not always offer the best treatment.
Sjöstrand
U H
UH
Department of Anesthesiology, University Hospital, Uppsala, Sweden.
D000818:Animals; D001999:Bronchoscopy; D006612:High-Frequency Ventilation; D006801:Humans; D007828:Laryngoscopy; D011659:Pulmonary Gas Exchange; D012120:Respiration Disorders / Q000628:therapy; D012121:Respiration, Artificial; D013552:Swine; D013903:Thoracic Surgery