Electrolytes

Chloride Major Extracellular anion Maintains hydration, osmotic pressure, ionic balance Changes parallel changes in Na ISE Silver Chloride/silver sulfide sensing element Also colorimetric and coulometric- amperometric Sweat Chloride Cystic Fibrosis

Chloride Clinical Significance Normal Range ( mmol/L) Increased Hyperparathyroidism, renal tubular disease, diarrhea, dehydration Decreased Salt losing renal disease, overhydration, prolonged vomiting, burns

Sweat Chloride 17 th Century Saying “Woe to that child who when kissed on the forehead taste salty. He/She is bewitched and soon must die” Pilocarpine nitrate A stimulant which causes localized sweating so that sweat may be collected and analyzed

Sweat Chloride Cystic Fibrosis

CO 2 Primarily bicarbonate Keep sample capped to prevent loss of CO 2

CO 2 Clinical Significance Normal Range (23-30 mmol/L) Increased Metabolic Alkalosis, Compensated respiratory acidosis, Emphysema Decreased Metabolic Acidosis, Compensated respiratory alkalosis, Hyperventilation

Anion GAP (Na + K) – (Cl+ CO 2) (10 -20) Or Na – (Cl +CO 2) (8-16) Difference between unmeasured anions and unmeasured cations Increased Renal failure, diabetic acidosis, lactic acidosis, drugs or toxins or lab error Decreased QC Check Can’t be a negative number Analytical error, such as false elevated Cl or low Na Lipemia

Critical Value