venturi injector

Laser surgery offers several advantages to the surgeon and patient: microscopic precision, a bloodless operative field, and complete sterility. While the majority of procedures pose few problems beyond protection of the eyes of operating room personnel and patients, microlaryngeal surgery with the CO2 laser requires very careful anesthetic management. A preoperative visit to determine the degree of existing airway obstruction is mandatory in deciding the safest anesthetic technique. Continued communication and cooperation between the surgeon and anesthesiologist throughout the procedure will help minimize the conflicting needs for airway access and ventilation...

The use of the Sanders venturi system during bronchoscopy in adults has been studied extensively. Its use in paediatric bronchoscopy has been limited because small changes in the characteristics of the system may produce large changes in the patient. With jet ventilation, peak inflation pressures and flow rates are influenced by the driving pressure, diameter and shape of the bronchoscope, the diameter of the injector and its length and angle from the axial line of the bronchoscope. Storz 3 mm, 4 mm and 5 mm rigid fibreoptic bronchoscopes were evaluated in a test lung with an injector of 1...

The Venturi is a flow-accelerating injector, activated by fresh gas inflow from the anaesthetic machine. The Venturi entrains exhaled gas from the patient through a soda-lime canister, and carries it to the patient together with fresh gas. The Venturi circuit is a Mapleson D system and the fresh gas requirements are roughly 30 ml kg-1 min-1 for anaesthetized, relaxed, adult patients under controlled ventilation.

Results of experimental and methodical investigations of so-called "Injector-Ventilation" or jet ventilation verify procedures' safety regarding ventilation and anaesthesia management. Classification of jet ventilation permits delimitation to IPPV and different methods of HFV. Resulting from considerations, especially based on reported insignificancy of "Venturi-Effect" under clinical conditions, authors suggest use of unitary term "Normo-Frequent Jet Ventilation" (NFJV).

Including a venturi injector in a Magill breathing attachment reduces the requirement of compressed gases to 40% of that normally used: 100-120 ml x kg-1 x min-1. The entrainment of ambient air through the venturi injector enables the supply of an adequate flow of gas mixture to the patient. In 10 awake volunteers and 12 patients under N2O/halothane anaesthesia, it was demonstrated that a fresh gas flow from the anesthetic machine of 40 ml x kg-1 x min-1 is sufficient to prevent rebreathing during spontaneous respiration, when the venturi injector is included in the Magill attachment...

Basing on Sander's inject-ventilation and Venturi's principle problems of the jet-ventilation with free-jet and injector-ventilation with jet-pump-effect are discussed, and theoretical aspects of the own method are presented.

The relation between three-dimensional geometry of the inflow tract to the orifice and the area, shape, and velocity of regurgitant jets was studied in a pulsatile in vitro color Doppler flow model. A 2.5 MHz transducer connected to a diagnostic ultrasound machine was placed in a water tank facing pulsatile jets (duration, 0.5 second) obtained by a calibrated injector. Flow rate from 6 to 52 ml/sec were tested through a 5 mm diameter circular orifice. Four different three-dimensional inflow tract geometries were compared: (A) sharp-edged, (B) Venturi (funnel), (C) converging conical, and (D) diverging conical...

Reported is a system of apparatures to control characteristic changes of cardiorespiratory function during different methods of endoscopic ventilation. The aim of the study is to measure and record simultaneously and continuously ECG, thoracic movement, tracheal pressure, pulmonary artery pressure and arterial oxygen pressure using transcutaneous technique. Measurements of arterial blood pressure and blood gas analysis (PaO2, PaCO2, BE, HCO3-, pH) are carried out in intervals. Four different methods of injector-ventilation are compared with the conventional laryngoscopic ventilation on the basis of a test program...

The size of inhalation equipment deadspace in infant anaesthesia is of critical importance. While endotracheal intubation reduces anatomical deadspace, the added deadspace of the tube connector tends to increase the overall deadspace by 6 to 10 ml. In order to ensure optimal gas exchange at minimal respiratory effort a new tube was designed which separates inspiratory gas down to the level of the vocal cords and maintains rapid gas flow by a Venturi injector. In controlled air ventilation this tube improves arterial pO2 by 15% and reduces tidal-volume 35% compared to Magill tubes of equal size...

A simple modification of a B.O.C. slide valve is presented, for controlling the injector flow in venturi ventilation.

A technique of anaesthesia for microlaryngeal surgery is described utilizing a new catheter and the venturi jet injector. Access and exposure for the surgeon are excellent and the laser can be used without special precautions. The central position and lack of movement of the distal end of the tube in the trachea prevent the potential complication of rupture of the trachea or of a bronchus.