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C L Cousins

Publications and source records attributed to C L Cousins.

12 recordsLinked to original sources
PubMed1988

Comparison of serum sodium and chloride results for Flame IV-Auto Analyzer II, SMAC, Ektachem 400, and Nova 4 clinical analyzer systems.

We determined serum Na+ and Cl- results using Technicon's Flame IV-Auto Analyzer II (FLIV/AAII) system and Kodak's Ektachem 400 clinical analyzer. Our objective was to determine whether Na+ and Cl- results from these analyzers were sufficiently similar to report to clinicians without reference to the system used for the determination. Method precision of the two systems for Na+ results was comparable; whereas Ektachem 400 Cl- results were more imprecise than those determined using the FLIV/AAII, Ektachem Na+ results showed lower correlation with the FLIV/AAII (r = 0.890) and Cl- results were more highly correlated (r = 0.960). When Kodak's newly developed equi-transferant electrolyte reference fluid (ETRF) was used with generation 4 Na+ slides and generation 1 Cl- slides the largest difference observed was 7.0 mmol/L for both Na+ and Cl- results. Using Kodak calibrators and the manufacturer's operational conditions for the Ektachem 400, we observed that a considerable number of sample results for both Na+ and Cl- did not agree within 3.0 mmol/L of the FLIV/AAII values. To corroborate our finding, we also analyzed serum Na+ and Cl- using a Technicon Sequential Multiple Analyzer + Computer (SMAC) system and a Nova 4 + 4 Clinical Analyzer (Nova). We conclude that flame emission systems and direct ion specific electrode systems do not yield comparable Na+ and Cl- results even when total protein and triglyceride concentrations of the samples are within reference ranges.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoanalysis↗
PubMed1985

Comparison of precision for the Kodak Ektachem 400 and Technicon AutoAnalyzer II creatinine methods.

We have evaluated the precision of the Ektachem 400 thin film enzymic creatinine method and compared it to that obtained for an AutoAnalyzer II (AAII) picric acid procedure. The results of the study show that the Ektachem method yields imprecise creatinine values over the low concentration range (40-240 mumol/L). Run-to-run precision estimates at a creatinine concentration of 225 mumol/L (by AAII) yielded CV's of 9.3 and 2.6% for the Ektachem 400 and AutoAnalyzer II methods respectively. The Ektachem 400 yielded imprecise creatinine determinations even when sample ammonia concentrations were less than 150 mumol/L. Patient samples analyzed by the AAII and Ektachem 400 over the creatinine range 40-900 mumol/L were highly correlated (r = 0.994). The correlation (r = 0.779) was low for patient data over the creatinine range 40-160 mumol/L. Creatinine results determined by the Ektachem 400 showed improved precision when samples were evaluated in triplicate using Kodak's latest (No. 8.5) software revision.

Ammonia↗
PubMed1985

Continuous-flow enzymic determination of serum total and high density lipoprotein cholesterol using microlitre sample volumes.

We determine serum total cholesterol and high-density lipoprotein cholesterol (HDL-C) using a modified Technicon Auto Analyzer II-BMC enzymic system. The method uses 25 microL of sample (serum or supernate) for cholesterol determinations. Pooled serum which was calibrated indirectly against CDC's Abell-Kendall method was used for standardization. Accuracy and precision for total cholesterol determinations are comparable to those obtained using a modified Technicon AAII method. Coefficients of variation for the determination of HDL-C prepared by heparin/Mn++ precipitation are 6.4% and 4.6% at concentration levels of 0.70 mmol/L and 0.94 mmol/L respectively. The interchangeable use of deionized-distilled water and 0.15 mol/L NaCl solution for dilution of samples analyzed by the micro method is shown to produce significantly different cholesterol estimates. The reduced reagent volumes significantly lower the cost of cholesterol determinations. The system is simple, inexpensive and yields reliable cholesterol and HDL-C results.

Autoanalysis↗
PubMed1985

Indirect measurement of infarct size. Correlative variability of enzyme, radionuclear angiographic, and body-surface-map variables in 34 patients during the acute phase of first myocardial infarction.

To gain a correlative perspective of indirect indications of the size of a myocardial infarct, we measured several body-surface electrocardiographic variables and several enzyme and radionuclear angiographic indicators of an infarct's size in 34 patients during the acute phase of first infarction. We found that bivariate correlations ranged widely, from an r value of 0.05 to an r value of 0.92, but were significantly (p less than 0.001) higher when variables from the same technique were correlated (mean r, 0.60 +/- 0.27), as opposed to correlations of variables from different techniques (mean r, 0.27 +/- 0.18). Trivariate comparisons among techniques produced significantly (p less than 0.001) higher r values, but the highest, an r value of 0.76 (total wall motion abnormality score; peak lactic dehydrogenase level; ST-segment integral maximum), indicated that even in this best case, only about 60 percent of the variation of one variable was dependent on or due to the two other variables. These data demonstrate that multiple indirect quantitative indicators of myocardial injury can vary widely in their correlations within the same population of infarcts, and much remains unknown in their relationships during the acute phase. Caution should be exercised, therefore, in their clinical application to predict an infarct's size in individual patients with acute myocardial infarction.

Adult↗
PubMed1984

Myocardial metabolism and haemodynamic responses with enflurane anaesthesia for coronary artery surgery.

Ten patients were studied before, during and after enflurane anaesthesia for coronary vein grafting. All had good ventricular function and nine were receiving effective beta blockade. Cardiac output and vascular pressures were measured, plus coronary sinus blood flow (CBF), myocardial oxygen consumption (MVO2) and lactate extraction (MLE). Enflurane induction (10 minutes, mean 1.72 per cent end tidal) reduced blood pressure (MAP), due to decreased cardiac index (CI), with no change in heart rate or systemic resistance. Intubation returned MAP and CI to control level but the heart rate increased. Subsequently, enflurane kept MAP, CI and stroke work below the awake level. CBF decreased on induction, rose again on intubation and remained normal before bypass. MVO2 fell on induction from an increase in CS oxygen content, which remained elevated. Normal MLE continued in every patient. There was no evidence of myocardial ischaemia in patients on beta blockade, when haemodynamics were maintained at or below those of the sedated, awake state.

Adult↗
PubMed1984

Myocardial metabolism and haemodynamic responses during high-dose fentanyl anaesthesia for coronary patients.

Fentanyl (mean dose 109 micrograms X kg-1) and oxygen were given to ten patients having coronary vein grafts. Serial studies were done before, during and after operation, of central and mean arterial pressures (MAP), cardiac index (CI) and coronary sinus flow (CBF) by thermodilution, myocardial oxygen consumption (MVO2) and lactate extraction (MLE). On induction CI and stroke work index decreased, but heart rate and MAP were unchanged as systemic resistance increased. Mean MAP and heart rate remained at the awake levels. Mean CBF remained unchanged along with stable MAP and coronary resistance. Oxygen content of CS blood increased on induction and remained elevated until the incision; it was above the awake level early postoperatively. MVO2 was low normal when the patients were awake and remained so. Normal MLE continued with a few exceptions. High-dose fentanyl did not uniformly abolish autonomic reflexes. Heavy premedication, complete beta adrenergic blockade and a high initial doses of fentanyl plus its continued infusion, aided in retaining a hypodynamic circulation and myocardial oxygenation.

Anesthesia, Inhalation↗
PubMed1984

The effects of nitrous oxide on myocardial metabolism and hemodynamics during fentanyl or enflurane anesthesia in patients with coronary disease.

Twenty patients about to have coronary artery bypass grafts were studied before and after 15 min of 50% nitrous oxide added to either fentanyl (75 micrograms/kg) or enflurane (0.5%) anesthesia. Arterial and central pressures and cardiac output were measured, plus coronary sinus blood flow and arterio-coronary sinus differences in oxygen, hemoglobin, and lactate contents. Fentanyl-N2O and enflurane-N2O both decreased systemic resistance, heart rate, cardiac output, and hence arterial pressure. Stroke work decreased significantly with little or no change in wedge pressure: ventricular function was impaired. Coronary flow and myocardial O2 consumption decreased with fentanyl-N2O. Oxygen extraction increased with enflurane-N2O, as did lactate contents of coronary sinus blood. Hemodynamic depression occurred from the combined effects of nitrous oxide and fentanyl or enflurane. The beta-blocked myocardia of nonstimulated coronary patients were becoming ischemic globally on 50% oxygen, after significant hypotension. From this and other evidence, we conclude that nitrous oxide may not be benign in patients with coronary arterial disease.

Adult↗
PubMed1980

Susceptibility of the bovine udder to bacterial infection in the dry period.

The teats of 18 cows were externally exposed to infection with mastitis organisms by dipping them daily for 1 or 2 weeks in a mixed suspension of Streptococcus dysgalactiae and Str. uberis at the start, the middle or the end of the dry period. The teat sinuses of quarters which remained uninfected after external exposure at the beginning or the middle of the dry period were then infused with the same strains of streptococci. Of the 9 quarters infected following external exposure 8 occurred in animals exposed at the start and one in the middle of the dry period. Thirty-six new infections occurred after infusion of bacteria into the teat sinuses of 38 quarters. In a further trial with 10 cows, Staphylococcus aureus and Str. zooepidemicus were inoculated into the distal 3 mm of the streak canals of 5 cows immediately after drying-off and into those of 5 cows which had been dry for 28 weeks. Animals were slaughtered 48 h later and infection determined by teat puncture. Five infections occurred in cows which were at the start of the dry period and only one in the cows dry for 28 weeks. It is suggested that these differences in the rates of new infection between the early dry period and a very extended dry period are due to differences in the ease with which bacteria can penetrate the teat canal. At the later stage bacterial growth through the teat canal appeared to be inhibited.

Animals↗