Electrolytes and other equally exciting topics

Transcription

1 Electrolytes and other equally exciting topics Rebecca A. Snyder Summer School 2010

2 Why do we care?

3 Why do we care?

4 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.

5 Hypokalemia Causes GI losses Diuretic use Signs/symptoms: Ileus Weakness, paralysis EKG changes: U waves, ST segments flattened, ventricular ectopy

6 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

7 Hypokalemia Treatment Give 1 gm IV Mg if K especially low (< 3.4) Availability equivalent (po = IV) Recheck K depending on situation, level

8 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

9 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

10 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)

11 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

12 Hypomagnesemia Causes Diarrhea Loop diuretics Signs/symptoms (same as hypocalcemia) Hyperactive DTR Tremors, tetany Chvostek s sign

13 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

14 Hypocalcemia Causes Hypoparathyroidism (after thyroidectomy) Renal failure Sepsis Rhabdomyolysis Pancreatitis **Massive transfusions**

15 Hypocalcemia Signs/symptoms Perioral numbness/tingling Paresthesias hands/feet Chvostek s sign Trousseau s sign (carpopedal spasm) EKG changes: long QT, VF

16 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

17 Hypercalcemia Causes: CHIMPANZEES Iatrogenic- thiazide diuretics Excess supplementation Malignancy/metastasis Signs/symptoms Fatigue, confusion, N/V Bradycardia heart block

18 Hypercalcemia Treatment: Hydration with isotonic fluid (NS) Loop diuretics (excretes Ca in urine) Bisphosphonates, calcitonin Dialysis

19 Hypophosphatemia Causes GI or renal losses Inadequate replacement in TPN Signs/symptoms Respiratory insufficiency, difficulty weaning from vent Weakness Cardiomyopathy

20 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

21 Hyponatremia Hypotonic Hypovolemic Euvolemic- SIADH, adrenal insufficiency, renal failure Hypervolemic- CHF, cirrhosis, nephrotic syn Isotonic Hypertonic- due to hyperglycemia, mannitol

22 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)

23 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

24 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

25 Arrhythmias Runs SVT, VT etc Send BMP Check EKG Give 2 gm IV Mg, 1 gm calcium

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