摘要:

In four series of patients, the efficiency of ventilation of a sine wave without an end-inspiratory pause was compared to a square wave without a pause, a sine wave with a pause to a square wave with a pause, a sine wave to a sine wave with a pause, and a sine wave with a long pause to one with a short pause. The primary mode of evaluation was through simultaneous airway and arterial argon washout curves. Additional cardiopulmonary measurements were made. Results indicate: (1) a statistically significant improvement in ventilation with a sine wave with a pause; (2) a statistically significant improvement with the longer pause as compared to the short pause.

ISSN:0090-3493    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

To establish the possible advantages of ultrashort acting barbiturates administered in continuous infusion as the only sedative agent for mechanically ventilated patients, sodium thiopental was given to 30 subjects for periods ranging from 2–14 days. Plasma levels were maintained at approximately 15 μg/ml, using both laboratory determinations and clinical judgment. This technique proved effective for patients requiring either controlled ventilation or intermittent mandatory ventilation. None of the hemodynamic and respiratory variables studied was significantly altered during the infusion, with the exception of decreased heart rates. In view of these results, the technique is considered both expedient and safe for prolonged sedation of patients requiring ventilatory support.

ISSN:0090-3493    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

Considerable controversy exists over the use of furosemide for the prevention or treatment of posttraumatic respiratory insufficiency. The conflict revolves around the use of a diuretic in a patient with this condition. There is some evidence that a nondiuretic effect of furosemide may be responsible for the reported improvement in lung function. We studied the response to furosemide of the pulmonary microvascular fluid filtration rate reflected in lung lymph flow (Qlym) in the normal lung. Using the unanesthetized sheep lung lymph preparation of Staub, we found a 30% decrease in Qlymafter 80 mg furosemide. However, the majority of the decrease occurred within 15 min after injection when diuresis was just beginning. This response appeared to be due to a large decrease in pulmonary venous resistance, decreasing hydrostatic pressure. Protein flow (QlymX lymph protein content) remained constant. Pulmonary artery pressure remained constant with left atrial pressure decreasing slightly. We have demonstrated that in the normal lung, furosemide significantly decreases the fluid filtration rate by a nondiuretic effect. Further studies of this response should help resolve the controversy over the indications for diuresis and center more attention on the actual mechanism of action of furosemide.

ISSN:0090-3493    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

Functional residual capacity (FRC) was determined by constant volume, whole body plethysmography in seven normal subjects under resting conditions and following the addition of increasing levels of expiratory positive airway pressure (EPAP). There was a significant increase in FRC in six of the seven subjects studied. Grouped data showed a progressive increase in FRC with increasing EPAP (p< 0.01). The highest level of EPAP (15 cm H2O) was associated with a 20% increase in FRC. We have been able to confirm that EPAP provides a simple and effective method of increasing FRC which could be applied to the treatment of conditions characterized by temporary and reversible reduction in lung volume.

ISSN:0090-3493    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

The term, optimal PEEP, requires redefinition in the light of new clinical data. With the onset of acute respiratory failure heralded by blood gas evidence of decreased oxygenation, PEEP is supplied in quantities sufficient to restore intrapulmonary shunt (Qsp/Qt) to a preselected goal of 15%. This is compatible with published criteria defining adequate blood gas exchange. Now rather than permitting reduction of cardiac output to be the end point of PEEP application, selective cardiovascular interventions to support preload, contractility, or afterload are made as appropriate so that cardiac function may be maintained until the preselected endpoint of shunt reduction to 15% can be made.

ISSN:0090-3493    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

Relative distribution of lactate, pyruvate, and glucose in cerebrospinal fluid, arterial blood, and jugular blood has been determined in patients in status of coma following cerebrovascular accidents and compared with values obtained in patients without CNS disorders. Ratios of lactate/pyruvate and arteriovenous differences were calculated. In the cerebrospinal fluid of these patients a significant increase of lactate concentration and of the lactate/pyruvate ratio was observed.

ISSN:0090-3493    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

To determine the relationship between brain energy metabolites and neurologic status after ischemia-hypoxia, we measured cortical tissue levels of adenosine triphosphate (ATP), phosphocreatine, and lactate. Rats with permanent unilateral carotid occlusion were exposed to 5, 10, and 15 min of hypoxic atmosphere (FIO20.048) and, to examine metabolic restitution, 60 min after recovery in rats exposed to the same hypoxic mixture for 15 min. At 5 and 10 min of hypoxia, there were significant reductions in phosphocreatinine and elevations in tissue lactate, but only after 15 min of hypoxia, did ATP levels significantly decrease. By 60 min after recovery, phosphocreatinine values returned to the normal range, ATP values to 15% less than normal, and tissue lactate toward normal. In parallel survival studies, neurological status was examined following hypoxic exposure (Pao218 to 19 torr) for 5 and 10 min. Evidence for neurological injury in the form of posthypoxic seizures occurred at a point in time preceding significant changes in brain tissue ATP level. Since injury occurs prior to ATP reduction, changes in brain tissue ATP level may not be an appropriate endpoint for determining brain tissue in jury in hypoxia.

ISSN:0090-3493    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

A difference between potassium concentrations in arterial plasma and venous serum was evaluated. The difference was 0.5 mM/liter, with a range of 0.1 to 1.1 mM/liter. Multiple factors operating primarily upon the venous sample are responsible for this difference. The value for arterial plasma potassium is stable and preferable, but a revised normal for arterial plasma K+is necessary.

ISSN:0090-3493    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

An unusual placement of a “central” venous catheter in the porto-hemiazygous system of a cirrhotic patient in septic shock is described. The catheter was misinterpreted as being located in a central vein and served initially as a guide for volume replacement. The high central venous pressure recorded (22 cm H2O) in spite of signs of hypovolemia led to the introduction of a Swan-Ganz catheter which confirmed the presence of hypovolemia. The proper position of the central venous catheter, especially in cirrhotic patients, should not only be confirmed by plain chest x-ray but also by injection of contrast medium.

ISSN:0090-3493    

出版商:OVID    

年代:1978

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1978

数据来源: OVID