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Biomedical subjects

A Kari

Publications and source records attributed to A Kari.

At least 73 records · Page 4Linked to original sources

Comparison of acceptance and performance of automated and manual data management systems in intensive care.

A computerized data management system for intensive care was compared to conventional manual record keeping. The criteria for the comparison were the nurses' acceptance, the reliability in recording haemodynamic trends and the ability of the physicians' to recall patient data after being on duty for 24 hours. At the time of the study the data management system had been in routine clinical use for 18 months. During the study the data management system was replaced by manual record keeping for three weeks. The majority of the nurses preferred the data management system to the manual record keeping. It was also more reliable in collecting data for trend graphs from the patient monitors. The physicians made significantly less mistakes in recalling patient data when the data management system was in use than during manual record keeping. According to the criteria of the study, the data management system was superior to the conventional manual system.

Computer Systems↗

Urinary excretion of polyamines: importance of circadian rhythm, age, sex, menstrual cycle, weight, and creatinine excretion.

The urinary excretion of putrescine, spermidine, spermine, and N1- and N8-acetylspermidines was measured in 95 volunteers. The 24-h excretion, split in four consecutive periods, was analyzed for circadian rhythm in eight volunteers. Circadian rhythm was observed in total polyamine and in N1- and N8-acetylspermidine excretions. The excretion rates of these polyamines were highest in the morning. The normal values for 24-h urinary excretion of polyamines were determined in 87 volunteers. Men excreted significantly more spermidine (P less than 0.001), N8-acetylspermidine (P less than 0.05), and spermine (P less than 0.001) than did women; putrescine excretion was higher in women (P less than 0.001). This variation was only partially explained by differences between sexes in body or muscle mass because most differences remained significant even after normalization for creatinine excretion and body weight. No correlation between the polyamine excretions and age or menstrual cycle was found.

Adult↗

Measurement of gas exchange in intensive care: laboratory and clinical validation of a new device.

The performance of a new gas exchange monitor was assessed both in laboratory simulation and in ICU patients. Laboratory simulation using N2 and CO2 injections resulted in a mean error of 2 +/- 2% in CO2 production (VCO2) and 4 +/- 4% in oxygen consumption (VO2) in respirator measurements (n = 55) and in a mean error of 3 +/- 2% in VCO2 and 4 +/- 2% in VO2 in canopy measurements (n = 25). The mean error in RQ during ethanol burning was 2 +/- 2% in respirator measurements (n = 45) and 1 +/- 1% in canopy measurements. FIO2 had little effect on the accuracy of VCO2, whereas the accuracy on high rates of VO2 (VO2 = 400 ml/min) was reduced, when FIO2 increased: the error ranged from 1 +/- 1% to 6 +/- 1%, except at VO2 400 ml/min during FIO2 0.8, where the error was 16 +/- 3%. Neither peak airway pressure (+13 to +63 cm H2O) nor PEEP (0 to +20 cm H2O) had an effect on the accuracy. The highest level of minute ventilation studied (22.5 L/min) reduced the accuracy slightly (mean error of VCO2 4 +/- 1% and VO2 7 +/- 2%). In patients during controlled mechanical ventilation, increasing FIO2 from 0.4 to 0.6 had no effect on the results. VO2 was consistently higher by gas exchange than by the Fick principle: 16 +/- 9% during controlled ventilation (n = 20), 21 +/- 8% on synchronized intermittent mandatory ventilation (n = 10) and 25 +/- 8% during spontaneous breathing. We conclude that the device proved to be accurate for gas exchange measurements in the ICU.

Analysis of Variance↗

Development of an expert system for haemodynamic monitoring: computerized symbolization of on-line monitoring data.

The development of intelligent alarm systems for intensive care benefits from the transformation of data from a quantitative to a qualitative mode. We constructed a computerized algorithm for the symbolization of on-line monitoring data of heart rate, systemic arterial, pulmonary arterial and central venous pressures, as well as central and peripheral temperatures. We tested the ability of the algorithm to symbolize the levels of the parameters and to detect significant long-term trends in ten adult patients admitted to the intensive care unit after cardiac surgery. The estimations of an experienced clinician were taken as the 'gold standard'. The symbolization of the levels of the monitored parameters was in agreement with the clinician in 99.4% of the estimations. The algorithm detected 93.0% of the trends correctly and also estimated their reliability. The clinician considered its estimations to be accurate in 96.2% of cases. On the other hand, the clinician considered unreliable 2.4% of all the trends detected and classified as reliable by the algorithm. The computerized algorithm for the symbolization of real-time monitoring data performed efficiently enough for its further use in expert systems for intelligent monitoring.

Algorithms↗

The median filter as a preprocessor for a patient monitor limit alarm system in intensive care.

We studied the effects of removing brief variations in the monitoring data on the quality of limit alarms during the postoperative haemodynamic monitoring of cardiac patients. The variations were removed by median filtering. The false alarm frequency was reduced by more than two-thirds compared with a typical patient monitor. We designed and clinically tested a novel dual-limit alarm system with two median filters. The proportion of true alarms increased from 12% to 49% as compared to a typical patient monitor. The average false alarm frequency was 4.5 alarms per monitored hour. No correct alarms were missed.

Cardiac Surgical Procedures↗