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O Keinänen

Publications and source records attributed to O Keinänen.

5 recordsLinked to original sources
PubMed2005

Protein metabolism and strength performance after bovine colostrum supplementation.

This study was designed to determine the responses of muscle protein, serum amino acids, and strength performance to bovine colostrum supplementation in physically active men. The rest (R) group (n = 6) and the exercise (E) group (n = 6) carried out twice a 2-week experiment randomly assigned in a double-blind fashion with either placebo (PLA; consuming daily 20 g maltodextrin) or bovine colostrum (COL; consuming daily 20 g colostrum supplement) treatment with one month between. On the test day after the treatment period the measurements were carried out in fasting conditions and E carried out a strength training session (STS). The methods involved the infusion of ring-(2)H(5)-phenylalanine, femoral arterial and venous blood sampling, and biopsies from the vastus lateralis muscle. Serum concentration of essential amino acids during recovery was greater (p < 0.05) in the COL groups compared with the PLA groups. Both muscle protein synthesis and breakdown increased (p < 0.05) with COL. There were no differences in phenylalanine net balance or strength performance between the PLA and COL groups. It was concluded that a 2-week supplementation with bovine colostrum in physically active men increases serum concentration of essential amino acids but has no effect either on strength performance or protein net balance in fasting conditions during recovery after STS.

Adult↗
PubMed1997

Calculated versus measured oxygen consumption during and after cardiac surgery. Is it possible to estimate lung oxygen consumption?

BACKGROUND: Lung tissue is metabolically active and consumes oxygen. The oxygen content difference between arterial and mixed venous blood does not include the effect of pulmonary tissue oxygen uptake. Thus, oxygen consumption (VO2) of the lung should be reflected as a difference between VO2 measured by gas exchange and VO2 derived by the Fick principle. The purpose of this study was to measure in clinical conditions this difference (taken to represent the VO2 of the lung), and to evaluate the sources of error in lung VO2 estimation. METHODS: Nine patients undergoing coronary artery bypass grafting were studied. VO2 was measured by indirect calorimetry (VO2gasex) and compared to Fick-derived VO2 (VO2Fick) after induction of anaesthesia, after closure of the chest, at admission to intensive care, after stabilization of haemodynamics and during weaning from mechanical ventilation. The Fick-derived VO2 was calculated from blood samples taken at the beginning and at the end of each 20 min measurement period, and the mean of 12 consecutive thermodilution cardiac output measurements taken during each 20 min measurement period. RESULTS: VO2gasex was higher than VO2Fick (P < 0.01; in all except 4 of 45 measurements). The difference between the measured and the calculated VO2 was 33 +/- 25 ml/min (mean +/- SD, range -16-100 ml/min). This difference represented 14 +/- 3% (range 11-18%) of the whole body VO2. The VO2-difference was highest after the induction of anaesthesia (50 +/- 19 ml/min; range 20-41 ml/min, P < 0.03) and lowest on arrival at the intensive care unit (10 +/- 16 ml/min; range -16-39 ml/min). Core temperature did not correlate with the oxygen consumption difference. CONCLUSIONS: A constant difference between measured and calculated VO2 can be detected in carefully controlled clinical conditions. The difference between the two methods is due to both lung oxygen consumption and errors in the measurement of VO2 thermodilution cardiac output, haemoglobin and blood oxygen contents. We suggest that the perioperative changes of the VO2-difference are due not only to variation of the measurements but also to changes in lung metabolic activity.

Adult↗
PubMed1992

Continuous measurement of cardiac output by the Fick principle: clinical validation in intensive care.

OBJECTIVE: To compare continuous measurement of cardiac output by the Fick principle with the thermodilution cardiac output technique in hemodynamically unstable patients. DESIGN: An open comparison of two methods. SETTING: Multidisciplinary ICU in a university hospital. PATIENTS: Eight patients after coronary bypass surgery and 13 patients with hyperdynamic septic shock. All patients were mechanically ventilated. MEASUREMENTS AND MAIN RESULTS: The continuous Fick cardiac output technique was compared with the thermodilution cardiac output using both warm and cold injection in the coronary artery bypass surgery patients and using warm injection only in the patients with hyperdynamic septic shock. The mean difference between the continuous cardiac output technique and all thermodilution measurements (n = 201) was 0.6 +/- 19%. There was a good correlation between the continuous cardiac output and the warm thermodilution technique (n = 125, r2 = .79; p less than .001). When consecutive measurements with warm and cold thermodilution were compared with the respective Fick-derived values (n = 76), the mean differences between the Fick-derived and the warm and cold thermodilution cardiac output values were 0.2 +/- 1.0 L/min and 0.3 +/- 1.0 L/min, respectively. The relationship between Fick-derived and both methods of thermodilution-derived cardiac output was relatively constant during different modes of ventilatory support. The correlation between the thermodilution measurements with cold and room temperature injectate was weak (r2 = .36; p less than .001), whereas a good correlation was observed between the respective Fick-derived values (r2 = .73; p less than .001). The mean difference between the warm and cold thermodilution cardiac output measurements was 0.1 +/- 1.1 L/min and between the corresponding Fick-derived measurements was 0.01 +/- 0.7 L/min. CONCLUSIONS: Continuous measurement of cardiac output by the Fick principle offers a convenient, reproducible method for hemodynamic monitoring of unstable patients. The variation between the two tested thermodilution techniques is likely to reflect relatively rapid dynamic variation of cardiac output, which is filtered in the 1-min average of cardiac output obtained by the continuous Fick technique.

Adult↗
PubMed1989

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↗