High-frequency ventilation

High-Frequency Ventilation in Intensive Care and During Surgery, edited by G. Carlon and W. S. Howland... 

Positive-pressure ventilation (PPV) provides vital support to maintain adequate ventilation and oxygenation during the acute phase of RDS. Effective PPV is accomplished by generating a pressure that exceeds the closing pressure of the lung. Ventilation modes delivering this positive pressure are conventional mechanical ventilation (CV), high-frequency ventilation (HFV), patient proportional... 

Herridge MS, Slutsky AS, Colditz GA. Has high-frequency ventilation been inappropriately discarded in adult acute respiratory distress syn-dome Crit Care Med 1998 26 2073-2077. 

Kinsella, J. P., and Abman, S. H. (1993). Methemoglobin during nitric oxide therapy with high-frequency ventilation. Lancet 342, 615. 

Usually this type of anemometer does not provide information on the flow direction. Vice versa, the. sensors are made as independent of the flow direction as possible—omnidirectional. This is an advantage for free-space ventilation measurements, as the flow direction varies constantly and a direction-sensitive anemometer would be difficult to use. Naturally, no sensor is fully omnidirectional, but satisfactory constructions are available. Due to the high sensor thermal inertia, this type of anemometer is unsuitable for high-frequency flow fluctuation measurement. They can be used to monitor low-frequency turbulence up to a given cut-off frequency, which depends on the dynamic properties of the instrument. 

Several devices are also available to promote airway clearance. Flutter valve devices employ oscillating positive expiratory pressure (OPEP) to cause vibratory air flow obstruction and an internal percussive effect to mobilize secretions. Intrapulmonary percussive ventilation (IPV) provides continuous oscillating pressures during inhalation and exhalation. Finally the most commonly used technique is high-frequency chest compression (HFCC) with an inflatable vest that provides external oscillation. Vest therapy is often preferred by patients because they can independently perform the therapy even from an early age.5,14... 

HFOV High-frequency oscillatory ventilation a mechanical diphragm produces oscillations superimposed on a constant gas flow. Can provide from 180 to 900 breaths per minute. Both inspiration and expiration are actively promoted. 

HFJV High-frequency jet ventilation small volumes of air are released in a pulsating fashion through a jet nozzle, and directed down the airway in a patient simultaneously receiving conventional ventilation. Can provide from 240 to 660 breaths per minute. Inspiration is active, but expiration is passive, predisposing to air trapping. 

HFPPV High-frequency positive-pressure ventilation conventional mechanical ventilation at faster-than-usual rates. 

Derdak S. High-frequency oscillatory ventilation for acute respiratory distress syndrome in adult patients. Crit Care Med 2003 3 l(suppl) S317-323. 

Mehta S, MacDonald R, Hallett DC, et al. Acute oxygenation response to inhaled nitric oxide when combined with high-frequency oscillatory ventilation in adults with acute respiratory distress syndrome. Crit Care Med 2003 31 383-389. 

One of the potential advantages of metal stents over the plastic tube stents is the possibility of placement under conscious sedation by flexible endoscopy or fluoroscopy only. However, for a safe and durable access to the tracheobronchial system, the possibility for fine adjustments of the inserted stents, additional therapeutic measures, and permanent control of ventilation, most interventionists prefer to carry out stent implantations under general anesthesia and with the use of a rigid ventilating bronchoscope. Such a setting enables high frequency Venturi jet ventilation. 

Brian JK, Lippmann M. Particle transport through a hollow canine airway cast by high-frequency oscillatory ventilation. Exp Lung Res 1992 18(3) 385 t07. 

Langenderfer B. Alternatives to percussion and postural drainage. A review of mucus clearance therapies percussion and postural drainage, autogenic drainage, positive expiratory pressure, flutter valve, intrapulmonary percussive ventilation, and high-frequency chest compression with the ThAIRapy Vest J Cardiopulm Rehabil 1998 18(4) 283-289. 

The HIFI Study Group. High-frequency oscillatory ventilation compared with conventional mechanical ventilation in the treatment of respiratory failure in preterm infants. N Engl J Med 1989 320 88-93. 

Gonzalez F, Harris T, Black P, Richardson P. Decreased gas flow through pneumothoraces in neonates receiving high-frequency jet versus conventional ventilation. J Pediatr 1987 110 464-466. 

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