Electrolytes and other equally exciting topics Rebecca A. Snyder Summer School 2010
Why do we care?
Why do we care?
Why do we care? Torsades is bad. Because medical records cares even more. Because apparently saying that a patient is on the electrolyte repletion protocol is not enough.
Hypokalemia Causes GI losses Diuretic use Signs/symptoms: Ileus Weakness, paralysis EKG changes: U waves, ST segments flattened, ventricular ectopy
Hypokalemia Treatment: goal K > 4.0 KCl: Oral tablet (KCl SR) Oral liquid: give per tube only IV 10 meq/hr peripheral IV 20 meq/hr central line
Hypokalemia Treatment Give 1 gm IV Mg if K especially low (< 3.4) Availability equivalent (po = IV) Recheck K depending on situation, level
Special situations: Renal failure: Hypokalemia DO NOT PUT K in MIVF Rarely need replacement If replace, give small doses and recheck Repeatedly low, pt on lasix Schedule daily replacement po Supplement as needed Pediatric patient Replace ½ meq per kg as bolus
Causes Renal failure Hyperkalemia Reperfusion ischemic limb Rhabdomyolysis Succinylcholine Signs/symptoms EKG changes: peaked T waves, prolonged QRS, depressed ST segments Heart block, cardiac arrest
Hyperkalemia Clinically relevant when K > 5.5 Look at rest of labs, RECHECK- may be hemolysis Take K out of patient s IVF Order 12 lead EKG Treat, then recheck level Notify senior if needed (PREOP)
Treatment: Hyperkalemia Immediate/temporary 10 units IV insulin (NOT SQ) with 1 amp D50 1 gm IV calcium gluconate or calcium chloride Amp bicarb (Na bicarbonate, 1 amp= 50 meq) Albuterol nebs Longer lasting Kayexalate 50 g in water or sorbitol, po or pr Lasix Dialysis
Hypomagnesemia Causes Diarrhea Loop diuretics Signs/symptoms (same as hypocalcemia) Hyperactive DTR Tremors, tetany Chvostek s sign
Hypomagnesemia Treatment Expensive to check, often treat empirically Give 2 gm IV Mg (magnesium sulfate) Can give 4 gm IV at once for concerning arrhythmia First line treatment of torsades
Hypocalcemia Causes Hypoparathyroidism (after thyroidectomy) Renal failure Sepsis Rhabdomyolysis Pancreatitis **Massive transfusions**
Hypocalcemia Signs/symptoms Perioral numbness/tingling Paresthesias hands/feet Chvostek s sign Trousseau s sign (carpopedal spasm) EKG changes: long QT, VF
Hypocalcemia Calcium gluconate (PIV) Calcium chloride (CVL) Greater amt elemental Ca per volume Post op thyroids: Calcium carbonate Rocaltrol (vit D) dose 0.25 mcg/day
Hypercalcemia Causes: CHIMPANZEES Iatrogenic- thiazide diuretics Excess supplementation Malignancy/metastasis Signs/symptoms Fatigue, confusion, N/V Bradycardia heart block
Hypercalcemia Treatment: Hydration with isotonic fluid (NS) Loop diuretics (excretes Ca in urine) Bisphosphonates, calcitonin Dialysis
Hypophosphatemia Causes GI or renal losses Inadequate replacement in TPN Signs/symptoms Respiratory insufficiency, difficulty weaning from vent Weakness Cardiomyopathy
Hypophosphatemia Important to check/replace for patients on vent, s/p liver resection, on TPN Treatment: Give K-Phos if pt needs K Give Na-Phos if K adequate Usual dose 20 mmol
Hyponatremia Hypotonic Hypovolemic Euvolemic- SIADH, adrenal insufficiency, renal failure Hypervolemic- CHF, cirrhosis, nephrotic syn Isotonic Hypertonic- due to hyperglycemia, mannitol
Hyponatremia Treatment Beware central pontine myelinolysis Correct 1-2 meq per hr (max in one day 12 meq) Correct underlying cause Free water restriction (1-2L/day)
Hypernatremia Hypovolemic: burns, resp loss, RF Replace volume with ½or ¼NS Calculate FW deficit Euvolemic: DI, tube feeds Calculate FW deficit, can give per tube (240 q8h) or D5W If central DI: ddavp Hypervolemic: iatrogenic (Na bicarb) Loop diuretics (dialysis if RF) May need to give D5W with diuretic
Free Water Deficit FW deficit = 0.6 x wt (kg) x [(current Na/140)-1] Replace over 2 days, no more than 8 meq per day or 0.5 meq/l/hr http://www.medcalc.com/freewater.html
Arrhythmias Runs SVT, VT etc Send BMP Check EKG Give 2 gm IV Mg, 1 gm calcium