摘要:

The authors have used calcium ion (Ca++) sensitive field effect transistor (ISFET) probes to monitor in vivo changes in Ca++activity in the venous blood of dogs in response to infusions of sodium citrate or calcium chloride. During eight experiments, Ca++activity changes were monitored in response to sodium citrate infusions simulating infusion of 1, 2, or 4 units of citrate preserved blood per 6 min. The ISFET probe recorded decreases in Ca++activity during all infusions. Periodic serum samples were analyzed off-line using an in vitro ion selective electrode instrument. Analysis of variance showed no statistically significant differences between off-line sample and ISFET Ca++activities (p> 0.05).A second experiment tested the use of the Ca++ISFET as a control sensor for maintaining a desired Ca++level. These studies provided a range of Ca++activity values for comparison of off-line and ISFET values. Infusion rates of sodium citrate or calcium chloride needed to maintain venous Ca++activity at 1.0 mEq/L or 3.0 mEq/L for periods of 30 min ranged from 440 to less than 1 mg/min during maintenance periods. Observation of hemodynamics during the calcium ion control maneuvers suggests that calcium ion may be used to improve cardiovascular performance during critical care situations that involve cardiovascular instability.

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

A computer program for renal function in critically ill patients is described. The program was developed for use in a pocket computer allowing bedside evaluation of kidney function and hydration.

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

The use of continuous positive airway pressure (CPAP) and intermittent mandatory ventilation (IMV) in spontaneously breathing, intubated patients has prompted the development of new procedures for measuring functional residual capacity (FRC), The authors have developed a system for measuring FRC by the multiple breath nitrogen washout technique, which is suitable for use on intubated patients breathing with CPAP, IMV, or intermittent positive pressure ventilation (CONTROL) and on nonintubated patients. This system uses a pair of synchronized volume ventilators to permit a step change in inspired N2fraction while providing therapeutic ventilatory support. A rapid-response nitrogen analyzer and a modified bellows spirometer are used for continuous measurement of airway nitrogen concentration and expired gas flow rate. FRC is calculated on-line by a digital computer. The system accuracy was tested on a mechanical lung simulator in the CPAP and CONTROL modes. The measured volume was found to agree within 58 ± 52 ml of the actual volume in the CONTROL mode and within 104 ± 22 ml in the CPAP mode. The system was also tested for repeatability by making duplicate FRC determinations in patients with respiratory insufficiency. In the 18 patients studied, the correlation coefficient of these duplicate measurements wasr= 0.987 and the mean difference between measurements was 49 ± 24 ml. This noninvasive system also provides data used to calculate anatomical deadspace by Fowler's method (VSDS) and uniformity of ventilation (V/V) for multicompartment lung models.

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Popularity of the Seldinger technique of vascular cannulation has resulted in widespread use of spring guide wires. Though employed to make vascular cannulation easier and safer, guide wires are not without potential hazard. The review of guide wire design presented gives the operator an awareness of the potential problems inherent in their use. Three observed complications are described and suggestions are given for enhancement of utility and safety.

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID