1. Generic Case Review Robert Zaid 2/24/06

2. Chief Complaint 59 year old caucasion female brought in after falling down 13 stairs that morning

3. Consultation for medical management was ordered for our service

4. CC HPI PMHx MEDS Allergies SocHx FMHx ROS Physical Exam Differential LABS Radiological Differential Diagnosis Treatment History of Present Illness Pt is a 59 y/o c female who was found at bottom of stairs by her husband who noticed that she was having trouble breathing. Pt is unresponsive and unable to provide history and her husband does not know her history as well. This was her first admission to the hospital. She has consumed alcohol in the past day.

5. CC HPI PMHx MEDS Allergies SocHx FMHx ROS Physical Exam Differential LABS Radiological Differential Diagnosis Treatment Past Medical History Unable to obtain

6. CC HPI PMHx MEDS Allergies SocHx FMHx ROS Physical Exam Differential LABS Radiological Differential Diagnosis Treatment Medications Unable to obtain

7. CC HPI PMHx MEDS Allergies SocHx FMHx ROS Physical Exam Differential LABS Radiological Differential Diagnosis Treatment Allergies Unable to obtain

8. CC HPI PMHx MEDS Allergies SocHx FMHx ROS Physical Exam Differential LABS Radiological Differential Diagnosis Treatment Social History She is a smoker and drinks alchohol

9. CC HPI PMHx MEDS Allergies SocHx FMHx ROS Physical Exam Differential LABS Radiological Differential Diagnosis Treatment Family Medical History Unable to obtain

10. CC HPI PMHx MEDS Allergies SocHx FMHx ROS Physical Exam Differential LABS Radiological Differential Diagnosis Treatment Review of systems General: weight change, fever, chills, weak Head: headache, nasuea, vomitting Respiratory: SOB, wheeze, cough Cardiac: HTN, murmurs, angina, palpitations GI: appetite, n/v, incont., const/diarrhea GU: frequency, hesitancy, urgency, dysuria hematuria, incont., stones, no dyspareunia, no discharge MSK: muscle weakness, flank pain Neuro: parasthesias, loss of sensation Psychiatric- Pt is not depressed

11. CC HPI PMHx MEDS Allergies SocHx FMHx ROS Physical Exam Differential LABS Radiological Differential Diagnosis Treatment Physical Exam VS- BP- 113/65 HR 92 11 R 97 General- Pt is well nourished and not alert Heent- EOMI, PERRLA, no vision changes CV- RRR w/o murmurs or rubs, clicks or gallops RESP- Clear to auscultation bilaterally, no wheezes Abdomen- Soft, NT, ND, no masses, BS, no bruits GU- No discharge, bleeding, nodules or masses MSK- No weakness, EXT- No edema, negative moses, pulses b/l Skin- No rashes Ost- Neuro-

12. CC HPI PMHx MEDS Allergies SocHx FMHx ROS Physical Exam Differential LABS Radiological Differential Diagnosis Treatment Differential Need to rule out any foul play

13. CC HPI PMHx MEDS Allergies SocHx FMHx ROS Physical Exam Differential LABS Radiological Differential Diagnosis Treatment What do we want to order?

14. CC HPI PMHx MEDS Allergies SocHx FMHx ROS Physical Exam Differential LABS Radiological Differential Diagnosis Treatment Labs Chemistry CBC

15. CC HPI PMHx MEDS Allergies SocHx FMHx ROS Physical Exam Differential LABS Radiological Differential Diagnosis Treatment CBC 10.4 13.6 40.5 218 Chemistry 120 3.3 85 22 2 0.6 98 Pregnancy Test Negative

16. CC HPI PMHx MEDS Allergies SocHx FMHx ROS Physical Exam Differential LABS Radiological Differential Diagnosis Treatment

17. CC HPI PMHx MEDS Allergies SocHx FMHx ROS Physical Exam Differential LABS Radiological Differential Diagnosis Treatment Diagnosis 1.Medical management of hypokalemia with hyponatremia

18. Hyponatremia Background Maintenance –Homeostatic mechanisms Thirst Antidiuretic hormone (ADH) Renal handling of filtered sodium Clinically significant hyponatremia –Relatively uncommon –Nonspecific in its presentation Correction –Irreparable harm If corrected too quickly or too slowly

19. Hyponatremia Background Hypovolemic hyponatremia –Total body water (TBW) decreases –Total body sodium (Na+) decreases more –Extracellular fluid (ECF) volume is decreased. Euvolemic hyponatremia –TBW increases –Total sodium remains normal –ECF volume is increased minimally to moderately –No edema Hypervolemic hyponatremia –Total body sodium increase –TBW increases to a greater extent –ECF is increased markedly –Edema is present. Redistributive hyponatremia –Water shifts from the intracellular to the extracellular compartment –Resultant dilution of sodium –TBW and total body sodium are unchanged –Occurs with hyperglycemia. Pseudohyponatremia –Diluted by excessive proteins or lipids –TBW and total body sodium are unchanged –Hypertriglyceridemia and multiple myeloma

20. Hyponatremia Pathophysiology Regulation –Thirst –ADH –Renin-angiotensin-aldosterone system –Renal handling of filtered sodium Stimulation –Increases in serum osmolarity above the normal range (280-300 mOsm/kg) –Stimulate hypothalamic osmoreceptors –Cause an increase in thirst and in circulating levels of ADH Mechanism of ADH –Increases free water reabsorption from urine Low urine volumes Relatively high urine osmolarity Returning serum osmolarity toward normal ADH also is secreted in response to: –Hypovolemia –Pain –Fear –Nausea –Hypoxia

21. Hyponatremia Pathophysiology Regulation –Thirst –ADH –Renin-angiotensin-aldosterone system –Renal handling of filtered sodium Aldosterone –Synthesized by the adrenal cortex –Regulated primarily by serum potassium –Released in response to hypovolemia Renin-angiotensin-aldosterone axis –Effect: Causes absorption of sodium –Distal renal tubule Sodium retention obligates free water retention Aides the hypovolemic state.

22. Hyponatremia Pathophysiology Disorders of sodium balance –Disturbance Thirst Water acquisition ADH Aldosterone Rrenal sodium transport. Significant hyponatremia –State of extracellular hypo-osmolarity –Tendency for free water to shift from the vascular space to the intracellular space –Cellular edema is well tolerated by most tissues Not tolerated by calvarium –Cerebral edema. Rate –Slowly Several days or weeks –Brain is capable of compensating –Extrusion of solutes and fluid to the extracellular space –Fast 24-48 hours Compensatory mechanism is overwhelmed Severe cerebral edema may ensue Resulting in brainstem herniation and death.

23. Hyponatremia History Symptoms –May be limited Mild anorexia Headache Muscle cramps –Severe Obtundation Coma Status epilepticus Look for causes in history –Seen with chronic disease Pulmonary/mediastinal disease CNS disorders –Medications –Poor diet –Intake of large amounts of beer –Ectasy

24. Hyponatremia History Hypoosmolor hyponatremia –Hypothyroidism –Adrenal insufficiency Clinically significant hyponatremia –Anorexia –Nausea and vomiting –Difficulty concentrating –Confusion –Lethargy –Agitation –Headache –Seizures

25. Hyponatremia Physical Neurological –Level of alertness –Variable degrees of cognitive impairment (eg, difficulty with short-term recall; loss of orientation to person, place, or time; frank confusion or depression) –Focal or generalized seizure activity –Signs of brainstem herniation Severe hyponatremia –Coma; –Fixed, unilateral, dilated pupil –Decorticate or decerebrate posturing –Respiratory arrest Hydration status –Low volume Dry mucous membranes Tachycardia Diminished skin turgor Orthostasis –Excess free water (hypervolemic) Pulmonary rales S3 gallop Peripheral edema Ascites –Euvolemic Hypothyroidism Cortisol deficiency Syndrome of inappropriate antidiuretic hormone (SIADH)

26. Hyponatremia Causes Hypovolemic Euvolemic Hypervolemic

27. Hyponatremia Causes Hypovolemic hyponatremia –Sodium and free water are lost –Replaced by inappropriately hypotonic fluids –Mechanism Renal –Acute or chronic renal insufficiency »Unable to excrete free water –Salt-wasting nephropathy Nonrenal route –GI losses –Excessive sweating –Third spacing of fluids (eg, peritonitis, pancreatitis, burns) –Prolonged exercise in a hot environment

28. Hyponatremia Causes Euvolemic hyponatremia –Normal body sodium Total body excess of free water Patients who take in excess fluids. Psychogenic polydipsia Administration of hypotonic intravenous Infants who may have been given inappropriate amounts of free water

29. Hyponatremia Causes Hypervolemic hyponatremia –Sodium stores increase inappropriately –Acute or chronic renal failure Dysfunctional kidneys are unable to excrete the ingested sodium load –Cirrhosis –CHF –Nephrotic syndrome –Uncorrected hypothyroidism or cortisol deficiency –SIADH –Consumption of large quantities of beer or use of the recreational drug MDMA (ecstasy)

30. Hyponatremia Labs Questions about lab error –Was the patient's blood sample properly labeled? –Was it obtained from a venous site proximal to an infusion of hypotonic saline or dextrose in water? –Is laboratory measurement or reporting in error? –If an error is suspected, a second sample should be submitted for testing before therapeutic measures are initiated. Physiological states that show hyponatremia –The most common example is serum hyperglycemia. Extracellular glucose induces shift of free water from the intracellular space to the extracellular space. Serum sodium is diluted by a factor of 1.6 mEq/L for each 100 mg/dL increase in serum glucose.

31. Hyponatremia Labs –A similar phenomenon is observed in patients treated with glycerol or mannitol in an effort to control acute glaucoma or intracranial hypertension. This phenomenon is also seen in patients with advanced renal disease who receive radiocontrast agents for diagnostic testing. –Hyponatremia may be noted in patients whose serum contains unusually large quantities of protein or lipid. In these patients, an expanded plasma protein or lipid fraction leads to a decrease in the plasma water fraction in which sodium is dissolved. Laboratory techniques that measure absolute sodium content per unit of plasma water report low sodium levels despite the fact that the concentration of sodium in serum water remains within the normal range. This phenomenon, known as pseudohyponatremia, occurs when flame emission spectrophotometry or indirect potentiometry is used to assay serum sodium levels rather than direct potentiometry techniques. This occurs in approximately 60% of US laboratories. Serum osmolarity remains undisturbed, and attempts at correcting serum sodium are not indicated. Hyperlipidemia that is severe enough to produce pseudohyponatremia almost always is accompanied by a lipemic appearance of the serum sample. Hyperproteinemia of sufficient magnitude to induce pseudohyponatremia commonly is due to coexisting multiple myeloma.

32. Hyponatremia Labs Serum osmolarity –Low in hypo-osmolar hyponatremia –Normal in patients with pseudohyponatremia due to hyperlipidemia or hyperproteinemia –Normal or elevated in patients with hyperglycemia. Urine sodium levels –Helpful in distinguishing renal causes of hyponatremia from nonrenal causes. –<20 Hypovolemic hyponatremia Due to nonrenal causes –Vomiting –Diarrhea –Fistulas –GI drainage –Third spacing of fluids) –Avid renal absorption of tubular sodium –>20 Hypovolemic hyponatremia Due to renal causes Diuretics Salt-losing nephropathy Aldosterone deficiency

33. Hyponatremia Labs Urine osmolarity may be helpful in establishing the diagnosis of SIADH. –Typically, patients with SIADH have inappropriately concentrated urine with urine osmolarities in excess of 100 mOsm/L. –Patients with other forms of hyponatremia and appropriately depressed levels of ADH have urine osmolarities below 100 mOsm/L. TSH Adrenal function –Random serum cortisol levels or –Adrenocorticotropic hormone (ACTH) stimulation test –In patients who have taken oral steroids –or in any patient suspected of having cortisol deficiency

34. Thank you Questions, comments or concerns