			Home About us Contact

Test Lung (test + lung)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Tubeless combined high-frequency jet ventilation for laryngotracheal laser surgery in paediatric anaesthesia

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2000
G. Ihra
Background: High-frequency jet ventilation (HFJV) is an alternative ventilatory approach in airway surgery and for facilitating gas exchange in patients with pulmonary insufficiency. We have developed a new technique of combined HFJV utilising two superimposed jet streams. In this study we describe the application of tubeless supralaryngeal HFJV during laryngotracheal laser surgery in infants and children. Methods: Tubeless combined HFJV characterised by the simultaneous supralaryngeal application of a low-frequency (LF) and a high-frequency (HF) jet stream was evaluated in a clinical study in 10 children undergoing elective laryngotracheal CO2 laser surgery. Additionally, pressure and flow characteristics were determined with the use of a paediatric test lung. HFJV was applied by means of a modified Kleinsasser laryngoscope with integrated metal injectors. In addition to pulse oximetry, monitoring of ECG, heart rate and blood pressure, supraglottic airway pressure was measured and arterial blood gases were analysed. Results: Tubeless combined HFJV was used in 10 infants and children (mean age 4.6 yr, range 2 months,10 years) undergoing 17 consecutive endoscopic procedures with CO2 laser microsurgery of the larynx or the trachea under general anaesthesia. The mean duration of supralaryngeal HFJV was 46 min (range 15,75 min). Mean driving pressures of the HF and the LF jet streams were 0.75 bar and 0.95 bar, respectively. Inspiratory oxygen ratios were in the range 0.4,1.0. HFJV resulted in mean PaO2 and PaCO2 values of 19.7 kPa and 6.1 kPa, respectively. No complications during HFJV were observed. In the test lung, combined HFJV applied with driving pressures of 0.7,1.0 bar and 0.9,1.2 bar for HF and LF jet ventilation, respectively, resulted in maximum peak and baseline distal airway pressures of 17.6 cm H2O and 5.4 cm H2O, respectively. Conclusion: The application of the combined double frequency HFJV was effective in maintaining gas exchange in the presence of laryngeal or tracheal stenoses. It provided good visibility of anatomical structures and offered space for surgical manipulation, avoiding the use of combustible material inside the larynx or trachea. [source]

Feedback withdrawal and changing compliance during manual hyperinflation

PHYSIOTHERAPY RESEARCH INTERNATIONAL, Issue 2 2002
Julie Hila
Abstract Background and Purpose The performance of manual hyperinflation by physiotherapists can be improved by the availability of a pressure manometer. The present study aimed to test whether these benefits could be maintained when the manometer is withdrawn and whether the availability of a manometer affects the pressures delivered under changing respiratory compliances. Method Manual hyperinflation breaths were delivered to a test lung by student physiotherapists, with a target peak airway pressure of 30 cm H2O under control, feedback and feedback-withdrawal conditions. The breaths were delivered for three trials under each testing condition at each of three respiratory compliance settings. Results The availability of augmented feedback increased the accuracy and reduced the variability of performance; however, these improvements were not maintained when feedback was withdrawn. Changing respiratory compliance significantly affected the accuracy and variability during the control and withdrawal conditions, but the availability of a manometer negated these differences. Conclusions The availability of a pressure manometer negates the influence of respiratory compliance on the achievement of target peak airway pressures during manual hyperinflation in the laboratory environment, however these benefits are not retained when feedback is withdrawn. Therefore, it is recommended that a pressure manometer should be routinely available during manual hyperinflation in clinical practice to optimize treatment safety and effectiveness. Copyright © 2002 Whurr Publishers Ltd. [source]

Comparison of breathing tube connectors during invasive bronchial procedures,

ANAESTHESIA, Issue 6 2009
N. Rahe-Meyer
Summary Bronchoscopy and bronchial suctioning during intra-operative artificial ventilation often causes leakage from the ventilation circuit with a decrease in ventilatory parameters and possible workplace contamination with anaesthetic gases. Different connectors have been developed to reduce gas leakage. We evaluated the following connectors : VBM 2 mm, 3 mm and 5 mm, Bodai Suction-Safe, Bodai Bronch-Safe and Bodai Trach-Safe, as well as the BE 105-7, BE 105-8 and SH 7-45. Invasive bronchial instruments (catheters, bronchoscopes and bronchial blockers) with 1.67,7.33 mm diameter were used. Pressure-controlled ventilation was performed on a test lung using a ventilator. Sevoflurane concentration in the room was measured 0.2 and 1.5 m from the connector using a photo-acoustic infrared-spectroscope. The VBM connectors caused the least gas leak and ensured stability of ventilation parameters even at peak pressures when combined with smaller instruments. With instruments > 6 mm, BE 105-7, BE 105-8 and SH 7-45 connectors performed best. The Bodai connectors showed a reduced ability to prevent leakage and to keep ventilatory parameters stable. All connectors, excluding the Bodai Trach-Safe, prevented exposure to anaesthetic gases beyond the current safety recommendations when combined with the fitting instruments. The connectors showed different ranges of tightness, equivalent to different ranges of compatibility with the instruments used. [source]