ISSN:0090-3493    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Computer-based patient monitoring is a science in transition. Its purposes are vague, its technology variable, and there is no clear evaluation of its utility. Monitoring originally developed because of an intuitive feeling that if we knew more, we would be able to take better care of patients. Physiologic monitoring, statistical monitoring, and integrative monitoring will eventually combine to make a coherent patient care system. However, the subcomponents must be made to work before we reach this stage. It is still unclear what ICU measurements should be monitored and what to compute from those measurements. Once agreed upon, these measurements must be presented in human terms and, ultimately, used to make computer-based diagnosis. The day will come when the computer will be viewed as a tool to extend our medical power to let us take better care of the patient.

ISSN:0090-3493    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

A computerized ICU patient monitoring system is described. The bedside module is a general-purpose unit designed to replace the entire range of traditional monitoring devices. All user-interaction, signal processing, and data presentation in this unit are under the direct control of a microcomputer. The nurse-station module, also containing a microcomputer, is responsible for information routing, controlling nurse-desk equipment as well as data and signal presentation. The system has been in use since 1978 in our 8-bed surgical ICU and since 1980 in an 8-bed coronary care unit. The application programs for ECG, blood pressures, temperature, thermodilution cardiac output, and fluid balance are discussed. The programs for monitoring controlled ventilation are presented in detail. The possibility for feedback control of mechanical ventilation is reviewed. Examples of clinical advantages from automation are given.

ISSN:0090-3493    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

The critically ill patient places tremendous mental challenges and crucial time demands on intensive care nurses and physicians. Computers can ease these demands by automatically acquiring, storing, and displaying patient data. However, the computer can more effectively serve the staff if medical-decision protocols are implemented. This paper describes the use of a computer system designed to optimize medical care for the acutely ill patient.

ISSN:0090-3493    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

The need for closed-loop control of blood pressure in acute hypertension after cardiac surgery was evaluated by estimating the amount of nurse-time required to adjust the infusion rate of sodium nitroprusside. The evaluation consisted of a nationwide telephone survey of head nurses in postsurgical ICUs at 9 institutions performing cardiac surgery. By nurse estimate, the average time spent adjusting the nitroprusside infusion rate was 26% of the time the patients were being infused. When calculated from a hierarchical list of questions, the average nitroprusside adjustment time was 16%. Assuming that a closed-loop controller would be accepted in these ICUs, they would be used 40% of the time that the nurse and patient are on a 1-to-1 basis. It was concluded that a technically acceptable control design exists for clinical use, that at the present time there is a need for such a controller, and that the controller would be accepted by the clinical staff.

ISSN:0090-3493    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Computer techniques have been developed to image, noninvasively, anatomical structure, vessel blood flow, and physiological and biochemical functions, utilizing a number of physical principles. These devices, though costly, appear to provide sufficient diagnostic benefits to warrant their use in some critical care units. The emergence of x-ray, digital subtraction angiography, ultrasound, emission and nuclear magnetic resonance imaging techniques and their medical applications are described. It is shown that the physical variables measured by these techniques are sensitive to disease conditions and, thus, their incorporation in critical care procedures are likely in the future.

ISSN:0090-3493    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Indwelling chemical sensors have been designed and built which operate on similar principles to field effect transistors, the fundamental structural unit of the computer. By appropriate use of ion-filtering membranes with these devices, it is possible to measure, continuously, serum electrolytes, including hydrogen ion, and CO2tension. Semiconductor processing techniques allow incorporation of multiple ion sensors on a single miniaturized chip. Chip-based signal processing can also allow compensation for temperature effects and other sources of instability. Because these devices can be produced inexpensively, they seem to be promising for patient monitoring in the critical care environment. Problems with stability, blood compatibility, and reference electrode design are addressed and potential solution methods are proposed. The performance of preliminary devices in vitro and in vivo is discussed.

ISSN:0090-3493    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Hypocalcemia is an important metabolic problem in critical care medicine. To determine the frequency of this problem and the patient subsets at risk, a retrospective study of a large series of ICU patients was performed. During the study period, 259 patients were admitted to the ICU, of whom 210 (81%) had a serum calcium (Ca++) measured. Of these 210 patients, 135 (64%) were hypocalcemic (serum Ca++< 8.5 mg/dl) and 75 (36%) were normocalcemic. Serum albumin concentration was++concentration may have been normal in many of these patients. On the other hand, 32% of the hypocalcemic patients were alkalotic (pH ≥7.45) which indicates that ionized Ca++levels may have been low because Ca++binding to protein increases with alkalosis. Gastrointestinal bleeders and postabdominal surgery patients were more likely to have low total serum Ca++whereas cardiac and neurosurgical patients were more likely to have a normal total serum Ca++(p< 0.05). Ionized Ca++was calculated in 36 of the normocalcemic and 80 of the hypocalcemic patients. The hypocalcemic group had significantly lower ionized Ca++levels when compared to those of the normocalcemic group (p< 0.001). Patients with low serum Ca++values spent a longer time in the ICU (p< 0.01), had an increased incidence of renal failure and sepsis (p< 0.01), had an increased mortality rate (p< 0.002), and received a greater number of blood transfusions (p< 0.001) than patients in the normocalcemic group. It is concluded that: (1) hypocalcemia is a frequent finding in critically ill patients; (2) determining ionized Ca++levels is useful because many ICU patients have alterations in both arterial pH and serum albumin levels; (3) hypoalbuminemia, sepsis, red cell transfusions, and renal failure are predisposing factors for hypocalcemia; and (4) hypocalcemic patients do less well clinically than normocalcemic patients.

ISSN:0090-3493    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Hemodynamic and renal function response to low-dose (100 and 200 μg/min) dopamine infusion was studied in 15 adult cardiac surgical patients who manifested combined oliguria and left ventricular dysfunction postoperatively. Patients were studied an average of 6.6 h after ICU admission, at normothermia and after 2 consecutive hourly urine output determinations of less than 0.5 ml/kg h in the presence of a left atrial or pulmonary artery occlusion pressure over 12 mm Hg. Dopamine infusion at 100 μg/min produced improvement in creatinine, osmolar and free water clearances (70 ± 10 to 115 ± 13, 37 ± 4 to 93 ± 16 and –15 ± 2 to –37 ± 10 ml/min, respectively), and urinary sodium concentration (15 ± 5 to 29 ± 10 mEq/L). Urine flow improved overall from 22 ± 2 to 54 ± 9 ml/h; however, in 9 of 15 patients, flow was less than 0.5 ml/kg h (33 ± 5 to 50 ± 6 ml/h). In each of these 9 patients, dopamine infusion at 200 μg/min further improved urine flow as well as measured renal function. Plasma renin activity measured in 9 of the 15 patients before and during the 100 μg/min dopamine infusion was decreased from 1.95 ± 0.57 to 0.73 ± 0.39 mg/ml h. The hemodynamic effect of both dopamine doses was increased cardiac output coupled with decreased systemic (SVRI) and pulmonary vascular resistance index (PVRI). In these 15 patients, low-dose dopamine infusion produced significant improvement in renal function, with resolution of oliguria in every case, and with no deleterious hemodynamic effect.

ISSN:0090-3493    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

The effect of PEEP on oxygen consumption (Vo2) was observed in 3 groups of dogs. In addition to intermittent and indirect measurements using the expired gas collection and Fick methods, Vo2was measured continuously and directly using the “oxiconsumeter”, a device utilizing a relatively simple feedback controlled gas replenishment technique which adapts to standard ventilator circuits. One group of dogs served as controls, while the other 2 groups developed acute respiratory failure (ARF) subsequent to an acute pulmonary injury (API) induced by iv administration of oleic acid.In animals without API, there were no PEEP-induced changes in gas exchange variables; whereas the 2 API groups showed graded improvement in arterial oxygen tension (Pao2), shunt fraction (Qsp/Qt), and alveolararterial oxygen tension gradient [P(A-a)O2] during mechanical ventilation with PEEP. In the absence of vascular volume loading, increasing PEEP was associated with decreased cardiac output in dogs with or without API. In contrast, when concurrently fluid resuscitated, the dogs receiving the most severe API showed all of the classic signs of progressive ARF but did not evidence decreased cardiac output with increasing PEEP. Vo2decreased at high PEEP when oxygen transport decreased.The following conclusions were reached: The oxiconsumeter provides a safe cost-effective means for Vo2monitoring, whose convenience and rapidity exceed those of expired gas collections and whose accuracy and reliability far exceeds those of Fick determinations. In general, PEEP has little effect on Vo2provided cardiac output is adequate; in particular, Vo2cannot be used to optimize PEEP via correlation with lung compliance or intrapulmonary shunt fraction. Decreased Vo2during PEEP therapy reflects a significant decrease in cardiac output, and is indication to support cardiac output, or reduce PEEP, or both.

ISSN:0090-3493    

出版商:OVID    

年代:1982

数据来源: OVID