摘要:

This study examined the effect of several different high-frequency jet ventilation (HFJV) humidification techniques on tracheobronchial mucosa. Six groups (2 in each group) of mongrel dogs, chronically instrumented, were cared for in an intensive care-like setting for data acquisition. Four groups received HFJV with different humidification systems during 72 h of continuous ventilation. Two groups served as controls (conventional ventilation with and without humidity). Although there was significant damage to tracheal mucosa during ventilation without humidification, there were no significant pathologic differences in bronchial mucosa between humidified and nonhumidified groups. Several techniques of HFJV humidification produced no pathologic evidence of mucosal damage and could be clinically useful.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

The suction-biopsy channel (SBC) of a flexible bronchofiberscope was used to deliver gas into the trachea during high-frequency jet ventilation (HFJV) at a rate of 95 cycle/min and a tidal volume (Vt) of 95 ml. A Portex epidural catheter inserted into the SBC was used to entrain water for humidification by the injector principle. Inspired humidity (IH) was regulated by adjusting the distance (D) between the injector and jet portals. Airway pressures, pulmonary gas exchange and IH levels were measured in 11 dogs. In addition, tracheal cytology scores (TCS, a sensitive index of tracheal epithelial damage caused by breathing dry gases) were assessed in 12 patients. The system maintained adequate pulmonary gas exchange in both dogs and humans. In dogs the mean tracheal pressure was 2.8 ± 0.5 (SD) torr with a peak pressure of 3.8 ± 0.5 torr. The upper-airway pressure was subatmospheric (-2 ± 0.2 torr) during the first half of jet inspiration, but peaked synchronously with tracheal pressures during the second half. Both the upper airway and the trachea had a positive end-expiratory pressure (PEEP) of 1.8 ± 0.2 torr. When D was 0.3 cm, the system delivered gas with an IH of 44 mg H2O/L (almost saturated at 37°C). Human TCS did not change significantly after 2 h of humidified HFJV, suggesting efficient humidification.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

With the addition of appropriate logic circuitry and a single-board microcomputer, a thermistor flowmeter becomes a clinically useful ventilation monitor. The microcomputer calculates upper and lower reference (voltage) levels from the baseline (normal) flow signal generated by the thermistor bridge. If the flow signal fails to pass repetitively through one or both of these reference levels, visual and audio alarms are generated. Tests performed with both high-frequency (3 Hz) and low-frequency (0.2 Hz) ventilator systems show the usefulness of this system in sensing a variety of malfunctions, including endotracheal tube occlusions, leaks, changes in flow or tidal volume, and hose disconnects.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

We compared the tracheobronchial histopathology seen after conventional mechanical ventilation (CMV) and high-frequency jet ventilation (HFJV) in 44 adult cats. Two different HFJV humidity systems were examined: one used entrained mist alone, and the other infused 3 ml/kgh of 0.45% NaCl directly into the jet stream. HFJV produced more tracheal damage than CMV. This damage occurred at the endotracheal tube tip. The pattern of injury was acute inflammation, with erosion, necrosis, and infiltration of polymorphonuclear (PMN) leukocytes. The HFJV humidity system using entrained mist alone produced more damage than the HFJV infusion-pump humidity system. HFJV also produced more luminal mucus at all airway levels. Lower airways had different injury patterns. After 16 h, CMV produced more histopathology in the carina and main-stem bronchi. Here, the injuries were losses of surface cilia, losses of epithelial goblet cells, and inflammation. The dissimilar histologic injury patterns seen with 2 different forms of mechanical ventilation suggest different mechanisms of injury.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

High-frequency jet ventilation (HFJV) markedly improved the ventilatory status of 2 neonates with severe respiratory failure refractory to conventional mechanical ventilatory support. However, after approximately 1 wk of HFJV, both patients expired from causes not directly related to ventilatory compromise. Autopsy showed no gross alterations in tracheal or bronchial mucosa but did reveal microscopic lesions which could be attributable to HFJV.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

A simple volumetric system can be used to measure leakage from bronchopleural fistulas even when inspiratory volumes are unknown or when constant suction is required.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

A 26-yr-old woman with bilateral staphylococcal pneumonia developed respiratory failure. Conventional ventilation failed and high-frequency jet ventilation (HFJV) was successfully instituted. Bronchopleural fistulas required prolonged (73 days) support with HFJV. A bronchoscopy performed after 37 days of mechanical support showed no abnormalities. Computed tomography (CT) of the chest demonstrated severe cystic abnormalities. Pulmonary function tests performed 1 and 6 months after recovery showed small-airway dysfunction. HFJV proved safe for prolonged use.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

High-frequency jet ventilation using a jet injector located at the right mainstem bronchus was superimposed on standard mechanical ventilation to ventilate the injured lung of a patient with unilateral massive atelectasis secondary to pulmonary hemorrhage. This technique of differential ventilation markedly improved arterial oxygenation in this patient and may prove to be a simpler modality of respiratory support in patients who have respiratory failure from unilateral lung disease.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID