Clinical biochemistry
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Clinical biochemistry · Jun 2005
Osmolality revisited--deriving and validating the best formula for calculated osmolality.
To derive a formula that can be used (i) to calculate osmolality in normal patients as well as those that are hyperglycemic and intoxicated, and (ii) to predict the presence of unexplained compounds with the osmol gap calculation in the presence and absence of ethanol. DESIGN AND EXPERIMENTS: We performed in vitro experiments to determine the relationship of serum osmolality with sodium, potassium, urea, glucose, ethanol, methanol, and ethylene glycol. Several formulas were then tested for their validity in predicting osmolality in normal individuals. Finally, we assessed whether these formulas would allow us to calculate the osmolality gap (OG) that may be indicative of the presence of other osmotically active compounds. The OG calculation was done both in the presence and absence of ethanol. In this way, the OG should be able to detect compounds like methanol and ethylene glycol even in the presence of ethanol which is easily measured and is very often present in the above-named poisonings. ⋯ This study shows that factors of 1.20 and 1.15 have to be applied to ethanol and glucose to allow for accurate calculation of osmolality and osmolality gap. There were insufficient patient data to verify the factors for methanol and ethylene glycol.
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Clinical biochemistry · Jun 2005
Comparative StudyComparison of three strategies for myocardial protection during coronary artery bypass graft surgery based on markers of cardiac damage.
To evaluate myocardial damage during coronary artery bypass grafting using three different intermittent cardioplegia and then measuring cTnI and CKMBm release. ⋯ A strategy of normothermic cardioplegia seems to preserve myocardium better than hypothermic cardioplegia.