摘要:

We developed a method to measure accurately pressures at the airway opening (Pao) and in the trachea (Ptr) in neonates during high frequency oscillatory ventilation (HFOV) from 15–30 Hz. All component parts of the pressure-measuring system were tested as a unit against a reference transducer in a closed chamber in which sinusoidal pressure waves could be generated. The resulting waveforms were displayed on an oscilloscope ahd measured. Ptr was measured through the intramural lumen of a Hi-Lo jet tracheal tube (National Catheter Co., Argyle, NY) opening 1 cm above the distal tip. Pressure readings from uncorrected waveforms indicated a discrepancy between measured and actual pressures, as high as 100% at frequencies of 100 Hz. When the resonance of the system was damped with a CorrecTORR (Norton Health Care Products, Akron, OH), the ratio of test to reference transducer output was flat ±5% from 0–160 Hz for the Pao system and flat ±4% from 0–100 Hz for the Ptr system. Ptr system accuracy was verified in an excised rabbit lung and the systems were used clinically in neonatal HFOV. We conclude that Pao and Ptr can be measured accurately during HFOV by this method.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Inexpensive 5-Fr, single-lumen polyvinyl catheters are light and flexible enough to be floated into the root of the pulmonary artery. True mixed venous blood samples can be obtained rapidly from these catheters, and pressure waves are insignificantly damped. In 36 (84%) of 43 dogs, after the catheter had been surgically introduced via the external jugular vein, its tip was positioned in the root of the pulmonary artery. Twenty hours later, the overall success rate rose to 91%. In 11 (92%) of 12 critically ill human patients the catheter's tip was rapidly placed in the root of the pulmonary artery after the catheter had been introduced percutaneously via the subclavian vein. Only 2 patients and 2 dogs exhibited ventricular extrasystoles.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Nonradioactive xenon is sufficiently radiodense to increase the density of gas-containing lung as seen in a computed tomography (CT) scan. Subtraction of a baseline CT scan from the xenon-enhanced CT scan can accentuate gas space differences by subtracting fixed tissue densities. The baseline scan and the scan obtained during wash-in of xenon (before equilibration) allow circulation of local ventilation. The xenon CT scan, thus, provides more precise information about distribution of ventilation than planar radiogas techniques. The technical aspects of application to a critically ill patient and the mathematical basis of the technique are presented.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

This study examines the effects of a patient's level of consciousness and the degree of nasogastric (NG) tube flexibility on the ease of NG tube insertion in patients who already have an endotracheal tube in place. The sample consisted of 121 patients who were admitted to the respiratory ICU of a large teaching hospital, where they underwent endotracheal intubation and subsequent placement of an NG tube. The number of attempts required for successful placement of each tube was recorded over a 4-month period and the data analyzed using a 2 × 3 factorial design. The 2 independent variables were degree of NG tube flexibility (flexible or rigid) and degree of patient consciousness (conscious, obtunded, or unconscious). The dependent variable was the number of attempted insertions per patient.The degree of NG tube flexibility significantly affected the ease with which the NG tube was inserted; the rigid tube required fewer insertion attempts than the flexible tube. The differences among levels of patient consciousness were not statistically significant, but there was a relatively strong, statistically significant interaction between the degree of tube flexibility and level of patient consciousness.

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

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:

Prolonged therapeutic paralysis with pancuronium is commonly used in ICUs to facilitate mechanical ventilation of patients with respiratory failure. Sedation is usually given concomitantly to reduce patient discomfort, but assessment of its adequacy is made difficult by the paralysis. We recently cared for a former ICU nurse who required prolonged mechanical ventilation and paralysis and received morphine as a sedative. When she recovered, she was able to relate her experiences. She stressed the need for very frequent reorientation to time and her desire for constant explanation and re-explanation of all procedures being done by the nursing and physician staff. Her experiences provide insights that allow all ICU staff to provide better care for patients requiring therapeutic paralysis.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

The effects of Paco2changes on intracranial pressure (ICP) often remain even after prolonged hyperventilation. Two representative cases are described where Paco2rises were directly related to serious rises in ICP after 4, 6, and 14 days of hyperventilation. This is common in head injuries and suggests that where hyperventilation is used to reduce ICP in the presence of brain swelling, withdrawal of the technique should be cautious.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

A patient with severe arterial hypoxemia in adult respiratory distress syndrome (ARDS) secondary to a fractured femur is reported. A marked discrepancy between the clinical condition and laboratory findings was observed. At one point, Pao2was below 4 kPa (30 mm Hg) on FIO20.21 without signs of tissue hypoxia. This patient illustrates beneficial effects of a leftward shift of the oxyhemoglobin dissociation curve.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID