22Guidelines for Hypernatremia Rx Determine and treat likely cause(s)Most common error is “underguesstimation” of water deficit:TBW x ([Na+(measured)] – [Na+(desired) ])/[Na+ (desired)]Replace H20 enterally if possibleFrequent monitoring
23Sodium Content of IVF’s (mEq/L) 3% saline: 5130.9% (normal) saline: 154Ringer’s Lactate: 130Half Normal (0.45%) saline: 775% Dextrose (D5W): 0
24Hypernatremia: Key Points [Na+] >145 mEq/LNet water lossCalculate the water deficit[Na+] >145 mEq/LUsually inadequate water intake in an obtunded/ill personIncreased [Na+] in ECF Water shift from ICF Cerebral shrinkage lethargy, coma, ICH from tearing of bridging veins
25Case 3 29 y/o man with severe muscle weakness. No vomiting or diarrhea.Normal physical exam.
31Hypokalemia Rx Recognize likely total body depletion 1 mEq/L decrease = mEq total deficiencyGradual oral replacementI.V. replacement if serum level less than 3 mEq/LCheck & Replace magnesiumConsider telemetry
32Hypokalemia: Key Points [K+] < 3.5: review medications, review health status[K+] < 3: interventionRecognize Mg+ is cofactorRenal/CV monitoring
33Case 459 y/o man with 3-days malaise, decreased mental acuity and responsiveness, slurred speech.ESRD on hemodialysis; HTN, DM, Hypothyroidism
34Disoriented and lethargic BP (supine) 148/79mmHg, HR 101/min (supine) RR 26/min, T 37.7oC.Mucous membranes are moist, neck veins are distended. Bilateral crackles and wheezes. Loud S peripheral edema.
37Begin I.V. infusion of normal saline for volume repletion What is the next most appropriate step in managing this patient?Begin I.V. infusion of normal saline for volume repletionAdminister 1 ampule dextrose and 10 units insulin I.V. for hyperkalemiaTransfer to the ICU and perform emergent peritoneal dialysisTransfer to the ICU and perform emergent hemodialysis
43Hyperkalemia: Key Points K>4.5: caution with medications, & monitorK>5.5: interveneCalcium (not kayexalate) is 1st lineCheck ECG
44SUMMARY Construct your differential Know the complications of therapy Know the implications of lack of therapyCalculate water/electrolyte needs… But repeated and frequent monitoring is most important.Electrolyte disorders may be a diagnostic clue or an expected consequence of therapy