Snapshot A 48-year-old female presents to the emergency room with mental status changes. Laboratory analysis of the patient's serum shows: Na+ 122 mEq/L, K+ 3.9 mEq/L, HCO3- 24 mEq/L, BUN 21 mg/dL, Creatinine 0.9 mg/dL, Ca2+ 8.5 mg/dL, Glucose 105 mg/dL. Urinalysis shows: Osmolality 334 mOsm/kg, Na+ 45 mEq/L, Glucose 0 mg/dL. Sputum cytology is shown. Introduction SIADH is a syndrome characterized by an increased ADH production an increased sensitivity to ADH Pathogenesis causes paraneoplastic syndromes small cell carcinoma of the lung cancer cells produce ADH ectopically CNS disturbances infection, stoke, tumor, trauma, hydrocephalus may also be cause by drugs NSAIDS, antidepressants, chemotherapy, clofibrate, narcotics, carbamazepine Presentation Symptoms mental status changes caused by cerebral edema Evaluation Labs hyponatremia secondary to dilutional effects of increase water resorption ADH increases aquaporin insertion in the collecting duct of the renal tubule urine osmolality > 100 mOsm/kg urine is always concentrated despite decreasing serum osmolarity serum osmolality < 275 mOsm/kg random urine sodium > 40 mEq/L Treatment Moderat symptoms - Lifestyle fluid restriction (not salt restriction) Moderate - severe symptoms - Pharmacologic demeclocycline induces ADH insensitivity specifically works at the vasopression type-2 receptor (V2R) can be used in patients with small cell carcinoma not routinely used conivaptan, tolvaptan ADH antagonist consider hypertonic saline (use cautiously) normal saline + diuretic (furosemide) Complications Central pontine myelinolysis (CPM) result of too rapid correction of hyponatremia
QUESTIONS 1 of 3 1 2 3 Previous Next Lab Values Blood Hematologic Cerebrospinal Sweat, Urine, and BMI Blood, Plasma, Serum Reference Range ALT 8-20 U/L Amylase, serum 25-125 U/L AST 8-20 U/L Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL Calcium, serum (Ca2+) 8.4-10.2 mg/dL Cholesterol, serum Rec: < 200 mg/dL Cortisol, serum 0800 h: 5-23 μg/dL //1600 h: 3-15 μg/dL 2000 h: ≤ 50% of 0800 h Creatine kinase, serum Male: 25-90 U/LFemale: 10-70 U/L Creatinine, serum 0.6-1.2 mg/dL Electrolytes, serum Sodium (Na+) 136-145 mEq/L Chloride (Cl-) 95-105 mEq/L Potassium (K+) 3.5-5.0 mEq/L Bicarbonate (HCO3-) 22-28 mEq/L Magnesium (Mg2+) 1.5-2.0 mEq/L Estriol, total, serum (in pregnancy) 24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL 28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL Ferritin, serum Male: 15-200 ng/mLFemale: 12-150 ng/mL Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL Female: premenopause: 4-30 mIU/mL midcycle peak: 10-90 mIU/mL postmenopause: 40-250 pH 7.35-7.45 PCO2 33-45 mmHg PO2 75-105 mmHg Glucose, serum Fasting: 70-110 mg/dL2-h postprandial:<120 mg/dL Growth hormone - arginine stimulation Fasting: <5 ng/mLProvocative stimuli: > 7ng/mL Immunoglobulins, serum IgA 76-390 mg/dL IgE 0-380 IU/mL IgG 650-1500 mg/dL IgM 40-345 mg/dL Iron 50-170 μg/dL Lactate dehydrogenase, serum 45-90 U/L Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL Female: follicular phase: 5-30 mIU/mL midcycle: 75-150 mIU/mL postmenopause 30-200 mIU/mL Osmolality, serum 275-295 mOsmol/kd H2O Parathyroid hormone, serume, N-terminal 230-630 pg/mL Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L Phosphorus (inorganic), serum 3.0-4.5 mg/dL Prolactin, serum (hPRL) < 20 ng/mL Proteins, serum Total (recumbent) 6.0-7.8 g/dL Albumin 3.5-5.5 g/dL Globulin 2.3-3.5 g/dL Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h Thyroxine (T4), serum 5-12 μg/dL Triglycerides, serum 35-160 mg/dL Triiodothyronine (T3), serum (RIA) 115-190 ng/dL Triiodothyronine (T3) resin uptake 25%-35% Urea nitrogen, serum 7-18 mg/dL Uric acid, serum 3.0-8.2 mg/dL Hematologic Reference Range Bleeding time 2-7 minutes Erythrocyte count Male: 4.3-5.9 million/mm3Female: 3.5-5.5 million mm3 Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/hFemale: 0-20 mm/h Hematocrit Male: 41%-53%Female: 36%-46% Hemoglobin A1c ≤ 6 % Hemoglobin, blood Male: 13.5-17.5 g/dLFemale: 12.0-16.0 g/dL Hemoglobin, plasma 1-4 mg/dL Leukocyte count and differential Leukocyte count 4,500-11,000/mm3 Segmented neutrophils 54%-62% Bands 3%-5% Eosinophils 1%-3% Basophils 0%-0.75% Lymphocytes 25%-33% Monocytes 3%-7% Mean corpuscular hemoglobin 25.4-34.6 pg/cell Mean corpuscular hemoglobin concentration 31%-36% Hb/cell Mean corpuscular volume 80-100 μm3 Partial thromboplastin time (activated) 25-40 seconds Platelet count 150,000-400,000/mm3 Prothrombin time 11-15 seconds Reticulocyte count 0.5%-1.5% of red cells Thrombin time < 2 seconds deviation from control Volume Plasma Male: 25-43 mL/kgFemale: 28-45 mL/kg Red cell Male: 20-36 mL/kgFemale: 19-31 mL/kg Cerebrospinal Fluid Reference Range Cell count 0-5/mm3 Chloride 118-132 mEq/L Gamma globulin 3%-12% total proteins Glucose 40-70 mg/dL Pressure 70-180 mm H2O Proteins, total < 40 mg/dL Sweat Reference Range Chloride 0-35 mmol/L Urine Calcium 100-300 mg/24 h Chloride Varies with intake Creatinine clearance Male: 97-137 mL/minFemale: 88-128 mL/min Estriol, total (in pregnancy) 30 wks 6-18 mg/24 h 35 wks 9-28 mg/24 h 40 wks 13-42 mg/24 h 17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 hFemale: 2.0-8.0 mg/24 h 17-Ketosteroids, total Male: 8-20 mg/24 hFemale: 6-15 mg/24 h Osmolality 50-1400 mOsmol/kg H2O Oxalate 8-40 μg/mL Potassium Varies with diet Proteins, total < 150 mg/24 h Sodium Varies with diet Uric acid Varies with diet Body Mass Index (BMI) Adult: 19-25 kg/m2 Calculator ( ) xy AC 7 8 9 ÷ 4 5 6 × 1 2 3 - 0 . = + (M1.EC.75) A 57-year-old female presents to the emergency department with complaints of nausea, muscle aches, and confusion that presented and worsened over the past several days. On further probing, she also reports a nagging cough with shortness of breath and a 10-lb. weight loss over the last 3 months. She does not have a primary care doctor and denies having regular check ups. She reports smoking 1 pack of cigarettes per day and denies any alcohol consumption. Her medical history is significant for hypertension, a 30 pack year smoking history, and anxiety. Vital signs are as follows: T 37.2 C, HR 86, BP 137/86, RR 14, and SpO2 96%. Physical examination shows normal skin turgor, moist mucus membranes, and no peripheral edema. A CT scan is performed to investigate the patient's cough in Figure A. Lab work is performed in the ED and the findings are below.Na: 128 mEq/LPlasma osmolality: 260 mOsm/kgUrine osmolality: 250 mOsm/kgUrine Na: 47 mEq/LWhich of the following is most likely also found in this patient? Review Topic QID: 106822 FIGURES: A 1 History of increased consumption of fluids 12% (2/16) 2 Increased urine glucose 0% (0/16) 3 Kidney unresponsive to antidiuretic hormone 6% (1/16) 4 Increased antidiuretic hormone 75% (12/16) 5 Decreased antidiuretic hormone 6% (1/16) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 4 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.EC.79) A 48-year-old female presents to the emergency room with mental status changes. Laboratory analysis of the patient's serum shows:Na 122 mEq/LK 3.9 mEq/LHCO3 24 mEq/LBUN 21 mg/dLCr 0.9 mg/dLCa 8.5 mg/dLGlu 105 mg/dLUrinalysis shows:Osmolality 334 mOsm/kgNa 45 mEq/LGlu 0 mg/dL Which of the following is the most likely diagnosis? Review Topic QID: 100380 1 Aspirin overdose 13% (11/84) 2 Diarrhea 5% (4/84) 3 Diabetes insipidus 40% (34/84) 4 Primary polydipsia 14% (12/84) 5 Lung cancer 20% (17/84) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 5