الفهرس 
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Abstract
Over the last 20 years, the field of respiratory care has been inundated with
experimental studies and clinical reports involving the use of low volume, high
frequency ventilation.
This methods of ventilatory support IS characterized by the delivery of
positive pressure breaths at frequencies far in excess of physiological
respiratory rates and with tidal volumes approaching or less than, the estimated
anatomical dead space. of conducting airway. Clearly, high frequency ventilation
stands in marked contrast to conventional forms of mechanical ventilation in
which ventilatory frequencies and tidal volumes approximate those found during
normal spontaneous breathing.
The subject was discussed under the following headings :_
I) Historical review including the devolvement of artificial ventilation and
high frequency ventilation.
II) Physical principles of high frequency ventilation including various systems
used and modification.
III) Physiological consideration which include the following:
- Physiological effects of HFY where we dealt with mechanism of gas
exchange, response of pulmonary vagal mechanoreceptor to HFY, factors
affects CO2 elimination during HFY, its effects on
cardiovascular, cerebral and renal systems.
- Physiological effects of other types of controlled ventilation IPPY, PEEP,
CPAP, IMY, MMY & NEEP.
IV) HFY in anesthesia which include the following
- Intraoperative use :
1- Bronchoscopy and Laryngoscopy.
2- Laser microsurgery of the glottis and subglottis.
3- Tracheal reconstruction.
4- Intrathoracic surgery.
5- Abdominal surgery.
6- Extracorporeal shock wave lithotrepsy
7- Neurosurgery.
- Postoperative ventilatory support.
V) HFV in intensive care unit :
- Bronchopleural fistula.
- Acute respiratory failure.
- Adult respiratory distress syndrome.
- Respiratory distress syndrome in infants.
- Acute lift ventricular failure.
- Broncheal haemorrhage.
- Trachemalacia.
- Cardiac tamponade.
VI) HFV in emergency use.
VII) Hazard and problems of HFV.
VIII) Future of HFV.
HFV is a worthwhile addition to the methods of respiratory support and
should be used in all situation when the patient can benefit from its basic
advantages. Therefore, prevention of barotrauma and circulatory depression are
the tow main indications for HFV.
HFJV offers tow additional advantages. First, it can be administered though
a small bore catheter. Second, uncuffed endotracheal tubes can be used safely.