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The other electric lytes…. Jeffrey P Schaefer, MD April 23, 2007. Case. 58 year old female post-op hour 6 neck surgery twitchy and trouble breathing Calcium = 1.7 mMol (2.15 – 2.30 mMol). Differential diagnosis?. DDx - hypocalcemia. In hospital injured parathyroid glands
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The other electric lytes… Jeffrey P Schaefer, MD April 23, 2007
Case • 58 year old female • post-op hour 6 neck surgery • twitchy and trouble breathing • Calcium = 1.7 mMol (2.15 – 2.30 mMol)
DDx - hypocalcemia • In hospital • injured parathyroid glands • acute pancreatitis • uncorrected calcium for albumin
Albumin Correction • Corrected Ca = measured Ca + [(40 – alb) x 0.02] e.g. albumin is 20 g/l measured Ca = 1.90 mmol correction is 20 x 0.02 = 0.4 1.9 + 0.4 = 2.30 mMol
Clinical Findings • Neuromuscular (< 1.9 mmol/l) • tetany • mild (circumoral numbness, paresthesias of the hands and feet, muscle cramps) • severe (carpopedal spasm, laryngospasm, and focal or generalized seizures, which must be distinguished from the generalized tonic muscle contractions that occur in severe tetany). • non-specific symptoms • fatigue, hyperirritability • anxiety & depression • psychosis
Trousseau's sign • Inflate BP cuff to supra-systolic pressure x 3 minutes carpal spasm
Chvostek's sign • Contraction of the ipsilateral facial muscles (mouth, nose, eye) by percussing the facial nerve 1 cm anterior to the ear. • Present in 25% of normals.
Other Clinical • Papilledema • Myopathy • Derm • dry, puffy, coarse skin, dermatitis, britle nails. • Eye • cataracts • Dental defects • Cardiovascular • hypotension, heart failure, prolonged QT • GI • steatorrhea • Skeletal • rickets or osteomalacia • Endocrine • insulin release impairment, ovarian failure • Renal • renallithiasis
Case • 58 year old female • post-op hour 6 neck surgery • twitchy and trouble breathing • Calcium = 1.7 mMol (2.15 – 2.30 mMol)
Workup? • Calcium • Phosphate • Albumin • ECG – for interest • ABG? • I generally discourage • Use your judgment
Calcium Replacement • Oral Preferred • Calcium carbonate (500 mg elemental) • dose according to situation • 1,000 mg elemental qid is reasonable start • vit D3 0.25 to 0.5 ug od • IV if emergency • 10% ca-gluconate 90 mg / 10 ml x 1 to 2 ampules each over 3 – 5 minutes or longer • 10% ca-chloride 270 mg / 10 ml (AVOID)
IV Calcium for EMERGENCY • 10% Ca-gluconate x 6 amps into 500 ml of D5W = 540 mg / 560 ml = ~ 1 mg/ml • 0.25 – 0.50 mg / kg / hour infusion • BE CAREFUL – GOOD IV NEEDED • MONITOR FREQUENTLY • CO-ADMINISTER ORAL AND VIT D so as to GET OFF IV ASAP
Post-Surgical PT-ectomy • talk to the surgeon • stimulation of translocated glands may be important • i.e. do not ‘normalize’
Case • 59 year old female with breast cancer • obtunded • Ca = 4.5 mMol
Calcium • Hypercalcemia • constipation • abdominal pain and pancreatitis • myalgia • muscle weakness • gout & pseudogout • depressed mood • decreased LOC • coma • band keratopathy • shortening of QT interval
DDx Hypercalcemia • Malignancy • solid tumor • myeloma • Hyperparathyroidism • Excess Calcium / Vit D • Fracture • Bed rest
Case • 59 year old female with breast cancer • obtunded • Ca = 4.5 mMol • What’s your work-up & management?
Work-up • Clinical evaluation to differential dx. • Calcium • Phosphate • PTH • Protein electrophoresis • (electrolytes, renal function, CBC) • the rest can wait
Calcium Case • Calciuresis • Saline load • Furosemide • Calcitonin 4 IU/kg sq q12h 6-8 IU/kg q6h • Treat Underlying Disease • sarcoidosis • neoplasm • excess vitamin D / calcium intake • Bisphosphonate • Zoledronic acid 4 mg over 15 – 30 minutes • Pamidronate, Clodronate
Other Therapies • Dialysis • > 4.5 mmol/l (range) • Future • Inhibitors of PTH release • 22-oxacalcitriol • Induce Ab to paraneoplastic PTH • Calcimimetic • cinacalcet (Sensipar, AMG 703)
Case • 34 yr old homeless man presents to ED • poor nutrition • dehydration • recently assaulted • Admit for medical and social management • Day 2 PO4 = 0.20 mMol (0.8 – 1.5 mMol)
Common in IM-land • Refeeding: • medical diabetic ketoacidosis • surgery feeding NPO / bowel patient • psychiatry feeding anorexia nervosa • community nutritionally deprived patients
Hypophosphatemia No severe effects until < 0.3 mmol/l • Renal • increased urinary calcium loss stones • CNS • metabolic encephalopathy • irritability and paresthesias • confusion, seizures, delirium, and coma • CVS • heart failure (reduces inotropy) • respiratory failure due to weakness of the diaphragm • Muscle • proximal myopathy • dysphagia • ileus • rhabdomyolysis * ETOH supplement without PO4 • Blood • hemolysis • wbc dyfunction • defective clot retraction and thrombocytopenia
Case • 34 year old homeless man presents • Feels poorly • Day 2 PO4 = 0.20 mMol (0.8 – 1.5 mMol)
Phosphate • Sandoz Phosphate • 16 mmol / tablet • Milk and Food • glass of milk 25 mmol • Daily dose 80 – 115 mmol / day (divided)
IV Potassium-Phosphate • Avoid!!! • If needed: • no more than 0.08 mmol/kg over 6 hours • start oral replacement • Not Shown to be Beneficial in DKA
Hyperphosphatemia • Chronic • renal failure • Acute • very rare • oral load • tumor lysis hypocalcemia management • acromegaly never diagnose • familial tumoral calcinosis what’s that?
Case • 55 yr old alcoholic • blood tests done • Mg = 0.8 mMol (1.2 – 2.2 mMol)
Hypo-Mg • Renal Loss • Diuretics (loop and thiazide) • Alcohol • Hypercalcemia • Nephrotoxins • aminoglycosides • amphotericin • cisplatin / carboplatin • pentamidine • cyclosporine • Primary renal magnesium wasting • Gitelman's syndrome and Barrter’s Syndrome • renal mutations • GI Loss • acute or chronic diarrhea • steatorrhea • small bowel bypass surgery
Similar to hypocalcemia! • neuromuscular features • Hypokalemia • Hypocalcemia (PTH effect) • Widening of QRS and peaking of T
Treatment • Oral Preferred for very mild • 30 ml bid – qid Mg-rougier • IV Preferred for: • moderate or symptomatic • ongoing GI losses • 2 – 5 gram IV 1 gram / hour is generally safe • watch blood pressure!
Hypermagnesemia • Renal Failure • don’t give large doses of magnesium