Electrolytes and other equally exciting topics ♦♦♦
Rebecca A. Snyder Summer School 2010
VANDERBILT SURGERY Why do we care?
VANDERBILT SURGERY Why do we care?
VANDERBILT SURGERY 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.
VANDERBILT SURGERY Hypokalemia
Causes
¾ GI losses
¾ Diuretic use Signs/symptoms:
¾ Ileus
¾ Weakness, paralysis
¾ EKG changes: U waves, ST segments flattened, ventricular ectopy
VANDERBILT SURGERY Hypokalemia
Treatment: goal K > 4.0 KCl:
¾ Oral tablet (KCl SR)
¾ Oral liquid: give per tube only
¾ IV
10 meq/hr peripheral IV
20 meq/hr central line
VANDERBILT SURGERY Hypokalemia
Treatment
¾ Give 1 gm IV Mg if K especially low (< 3.4)
¾ Availability equivalent (po = IV)
¾ Recheck K depending on situation, level
VANDERBILT SURGERY Hypokalemia
Special situations:
¾ Renal failure:
DO NOT PUT K in MIVF
Rarely need replacement
If replace, give small doses and recheck
¾ Repeatedly low, pt on lasix
Schedule daily replacement po
Supplement as needed
¾ Pediatric patient
Replace ½ meq per kg as bolus
VANDERBILT SURGERY Hyperkalemia
Causes
¾ Renal failure
¾ Reperfusion ischemic limb
¾ Rhabdomyolysis
¾ Succinylcholine Signs/symptoms
¾ EKG changes: peaked T waves, prolonged QRS, depressed ST segments
¾ Heart block, cardiac arrest
VANDERBILT SURGERY 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)
VANDERBILT SURGERY Hyperkalemia
Treatment:
¾ 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
¾ Longer lasting
Kayexalate 50 g in water or sorbitol, po or pr
Lasix
Dialysis
VANDERBILT SURGERY Hypomagnesemia
Causes
¾ Diarrhea
¾ Loop diuretics Signs/symptoms (same as hypocalcemia)
¾ Hyperactive DTR
¾ Tremors, tetany
¾ Chvostek’s sign
VANDERBILT SURGERY Hypomagnesemia
Treatment
¾ Expensive to check, often treat empirically
¾ Give 2 gm IV Mg (magnesium sulfate)
¾ Can give 4 gm IV at once for concerning arrhythmia
¾ First line treatment of torsades
VANDERBILT SURGERY Hypocalcemia
Causes
¾ Hypoparathyroidism (after thyroidectomy)
¾ Renal failure
¾ Sepsis
¾ Rhabdomyolysis
¾ Pancreatitis
¾ **Massive transfusions**
VANDERBILT SURGERY Hypocalcemia
Signs/symptoms
¾ Perioral numbness/tingling
¾ Paresthesias hands/feet
¾ Chvostek’s sign
¾ Trousseau’s sign (carpopedal spasm)
¾ EKG changes: long QT, VF
VANDERBILT SURGERY Hypocalcemia
Calcium gluconate (PIV) Calcium chloride (CVL)
¾ Greater amt elemental Ca per volume Post op thyroids:
¾ Calcium carbonate
¾ Rocaltrol (vit D) – dose 0.25 mcg/day
VANDERBILT SURGERY Hypercalcemia
Causes: CHIMPANZEES
¾ Iatrogenic- thiazide diuretics
¾ Excess supplementation
¾ Malignancy/metastasis Signs/symptoms
¾ Fatigue, confusion, N/V
¾ Bradycardia Æ heart block
VANDERBILT SURGERY Hypercalcemia
Treatment:
¾ Hydration with isotonic fluid (NS)
¾ Loop diuretics (excretes Ca in urine)
¾ Bisphosphonates, calcitonin
¾ Dialysis
VANDERBILT SURGERY Hypophosphatemia
Causes
¾ GI or renal losses
¾ Inadequate replacement in TPN Signs/symptoms
¾ Respiratory insufficiency, difficulty weaning from vent
¾ Weakness
¾ Cardiomyopathy
VANDERBILT SURGERY Hypophosphatemia
Important to check/replace for patients on vent, s/p liver resection, on TPN Treatment:
¾ Give K-Phos if pt needs K
¾ Give Na-Phos if K adequate
¾ Usual dose 20 mmol
VANDERBILT SURGERY Hyponatremia
Hypotonic
¾ Hypovolemic
¾ Euvolemic- SIADH, adrenal insufficiency, renal failure
¾ Hypervolemic- CHF, cirrhosis, nephrotic syn Isotonic Hypertonic- due to hyperglycemia, mannitol
VANDERBILT SURGERY Hyponatremia
Treatment
¾ Beware central pontine myelinolysis
Correct 1-2 meq per hr (max in one day 12 meq)
¾ Correct underlying cause
¾ Free water restriction (1-2L/day)
VANDERBILT SURGERY Hypernatremia
Hypovolemic: burns, resp loss, RF
¾ Replace volume with ½or ¼NS
¾ Calculate FW deficit Euvolemic: DI, tube feeds
¾ Calculate FW deficit, can give per tube (240 q8h) or D5W
¾ If central DI: dDAVP Hypervolemic: iatrogenic (Na bicarb)
¾ Loop diuretics (dialysis if RF)
¾ May need to give D5W with diuretic
VANDERBILT SURGERY 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
VANDERBILT SURGERY Arrhythmias
Runs SVT, VT etc Send BMP Check EKG Give 2 gm IV Mg, 1 gm calcium
VANDERBILT SURGERY VANDERBILT SURGERY