Renal Considerations of Fluids and Electrolytes

Question 1

What is Hypokalemia

Answer 1

a serum potassium concentration of less than 3.5 mEq/L

Question 2

At what point is hypokalemia considered severe

Answer 2

a mEq/L of less than 2.5

Question 3

What typically causes deficits in potassium

Answer 3

poor dietary intake

excessive loss of body fluid (typically these losses are from the GI or renal systems)

Question 4

Often renal loss or potassium occurs from

Answer 4

diuretic treatment

or renal tubular / interstitial disease hyperaldosteronism

Question 5

Clinical features of Hypokalemia

Answer 5

mild- can be asymptomatic

Cardiovascular manifestations are the most important- hypotension, palpation and or ventricular arrhythmias, Cardiac arrest

Neuromuscular manifestations include: Generalized malaise, Skeletal muscle weakness / cramps, Smooth muscle problems with constipation and ileus

Question 6

Muscle cell breakdown known as ___________ is possible with decreased intracellular potassium levels

Answer 6

Rhabdomyolysis

Question 7

when critically low potassium (severe less than 2.5) you might see

Answer 7

Flaccid paralysis

Hypercapnia

severe rhabdomyolysis

Question 8

Diagnostic Findings of Hypokalemia

Answer 8

Serum potassium levels less than 3.5

EKG findings- flattened or inverted T waves, Prominent U waves, ST depression, Premature Ventricular Contractions.

Urine potassium less than 20 mEq/L suggests GI losses, while greater than 40 suggests Diuretic use

Question 9

How to treat emergency situation of hypokalemia

Answer 9

IV potassium chloride

Question 10

How to manage non-emergent situations of hypokalemia

Answer 10

oral Potassium therapy usually Potassium Chloride

Question 11

Important factor in treating hypokalemia

Answer 11

Ensuring to treat the underlying cause of the hypokalemia

Question 12

What level of total body potassium constitutes Hyperkalemia

Answer 12

greater than 5.0 mEq/L

Question 13

Hyperkalemia is most commonly associated with

Answer 13

• Renal Failure
• ACEi therapy (38% of hospital admissions)
• Potassium-sparing diuretic use (spironolactone)
• Hyporenimeic hypoaldosteronism
• Cellular death
• Metabolic Acidosis

Question 14

Clinical Features of Hyperkalemia

Answer 14

mild can be asymptomatic
- Severe- arrhythmias and death
- S/S are that are relatively common:
Numbness / tingling in extremities, muscle weakness, flaccid paralysis, Depressed or absent Deep Tendon Reflexes, Palpations

Question 15

Diagnostic findings of Hyperkalemia

Answer 15

serum pot. > 5.0 mEq/L

• if secondary to renal dysfunction; BUN and Creatinine will be elevated
• ABG’s may reveal metabolic acidosis

Question 16

EKG findings of Hyperkalemia

Answer 16

include: Peaked T waves , Prolonged PR segment, Loss of P wave, Prolonged ORS complex, ST-segment elevation, Ectopic beats and escape rhythms, Progressive widening of QRS complex, Sine wave, Ventricular fibrillation, Asystole, Axis deviations, Bundle branch blocks, Fascicular blocks

Question 17

Management of Hyperkalemia

Answer 17

aggressiveness depends on pot. level and evidence of cardiac toxicity

Life-threatening hyperkalemia should be treated immediately and look for cause.

Severe- Give IV Calcium Gluconate to stabilize cardiac membranes

Administer nebulized Albuterol (beta agonist)

Question 18

Management of Hyperkalemia

Answer 18

if severe… also add IV sodium Bicarbonate to lower potassium level. This draws Hydroen out of the cells

IV Glucose (dextrose 50 ) with IV insulin are also utilized

Question 19

Other treatment options for hyperkalemia

Answer 19

Diuretics that are not potassium sparing

Kayexalate - acts on GI to excrete Potassium

Dialysis - tx option if no other treatment works or if there are other contraindications to other treatments

Question 20

True or False- Sodium concentration is not actually demonstrating sodium serum levels

Answer 20

True- it is important to understand that it is actually reflecting disturbance in water homeostasis

Think of it as ore a representation of the total body amount of sodium

Question 21

Medical term for low sodium levels

Answer 21

Hyponatremia

Question 22

What sodium serum conc. defines hyponatremia

Answer 22

less than 135 mEq/L

Question 23

S/S might not occur in hyponatremia until what mEq/L level

Answer 23

125

Question 24

Many elderly pt’s are in a chronic form of mild hyponatremia (131-134 ish) especially when on BP meds. This is ok as long as it is stable and documented as such

Answer 24

True Statement

Question 25

What is the most common electrolyte disturbance seen in the hospital and is typically due to the fluids introduced Intravenously

Answer 25

Hyponatremia

Question 26

Pathophysiology for hyponatremia

Answer 26

too much water on board.

Question 27

DDx of hyponatremia should include:

Answer 27

``` Hypertonic fluid shift SIADH Acute renal failure Chronic Kidney Disease Cerebral salt wasting Diuretic therapy ```

Question 28

S/S of hyponatremia

Answer 28

- Nausea with or without emesis - malaise and or HA - Decreased level of consciousness - seizures - coma

Question 29

Diagnostic findings of hyponatremia

Answer 29

serum sodium concentration less than 135 mEq/L Now find a cause.. to do this utilize serum osmolality check urine osmolality check urine sodium conc.

Question 30

what is the purpose of serum osmolality in the diagnosis of hyponatremia

Answer 30

helps to differentiate between isotonic, hypertonic, and hypotonic hyponatremia If between 280-295 (isotonic) if greater than 295 (hypertonic) if less than 280 (hypotonic)

Question 31

Urine osmolality utilized for hyponatremia

Answer 31

if greater than 100 mOsm/kg then suggests that the kidneys are lakcing ability to dilute urine (not diuresing)

Question 32

How is urine sodium concentration utilized in hyponatremia examination

Answer 32

depending on the cause, urine sodium will either be increased or decreased if decreased- think CHF or Cirrhosis if increased- consider renal failure and diuretics

Question 33

Management of Hyponatremia

Answer 33

complex- depends on volume status, as well as severity and cause of hyponatremia if hypervolemic hyponat. such as CHF or Cirrhosis then - the underlying cause should be the focus of treatment, fluid restrictions salt restriction loop diuretics

Question 34

If SIADH is cause of hyponatremia (one of the most common) what is the management

Answer 34

First line treatment- free water restriction second line treatment- PO sodium tablets

Question 35

what should be used for pts that are hyponatremic and hypovolemic

Answer 35

extracellular volume should be replaced with isotonic fluid (0.9% NaCl)

Question 36

for severe symptomatic hyponatremia (neurologic symptoms) first line treatment should be prompt IV of?

Answer 36

Hypertonic Saline (3% NaCl) This can be dangerous and needs to be done in ICU...

Question 37

Repercussions of correcting hyponatremia too quickly | more than 4-8 mmol/L per day

Answer 37

can cause Osmotic Demyelination Syndrome | historically called Central Pontine Myelinolysis

Question 38

Key to successful treatment of hyponatremia

Answer 38

treating the underlying cause

Question 39

Pt should be sent to ICU for treatment of Hyponatremia if sodium conc. is less than what

Answer 39

125 mEq/L

Question 40

Hypernatremia is a common problem of

Answer 40

Sodium conc. exceeding 145 mEq/L

Question 41

what is the general causes of hypernatremia

Answer 41

impaired thirst and/or restricted access to water.

Question 42

common causes of hypernatremia

Answer 42

diarrhea, diuretic therapy, hyperglycemia, or DI

Question 43

pathophysiology of hypernatremia

Answer 43

extracellular fluid is hyperosmolar tis leads to neuronal cell shrinkage as water content is pulled out of cytoplasim This leads to temporary or permanent brain injury

Question 44

Mortality rates of ____ - ____ are seen in ICU pt's with serum sodium over 150 mmol/L

Answer 44

30-48%

Question 45

Risk factors for hypernatremia

Answer 45

- Advanced age - mental or physical impairment - Uncontrolled diabetes - Diuretic therapy - Hospitalization - Nursing home resident with inadequate nursing care

Question 46

Clinical features of hypernatremia

Answer 46

- Decreased level of consciousness - Restlessness/Irritability - Convulsions/Coma - Dry mouth and dry mucous membranes - lack of tears and decreased saliva production - Tachycardia / hypotension - Oliguria or anuria - Hyperventilation

Question 47

Diagnostic findings of hypernatremia

Answer 47

serum greater than 145 mEq/L serum osmolality greater than 290 mOsm/kg urine sodium concentration may be elevated or decreased dependent on the cause low urine sodium suggests DI

Question 48

Management of Hypernatremia

Answer 48

treat the underlying condition

Question 49

True or False- Hyovolemia should be treated last (with normal saline in a pt suffering from hypernatremia

Answer 49

False- this should be treated first

Question 50

when replacing volume in pts with hypernatremia it is very important to remember and consider

Answer 50

Rapid water replacement can cause cerebral edema

Question 51

what is Hypervolemia

Answer 51

state of decreased blood plasma volume

Question 52

possible etiologies of Hypovolemia

Answer 52

loss of blood loss of plasma loss of body sodium and intravascular fluid

Question 53

Clinical features of hypovolemia

Answer 53

``` extreme thirst nausea tachycardia hypotensive cyanosis / delayed CR Dizziness ```

Question 54

Hypovolemic shock treatment

Answer 54

Emergency oxygen to increase efficiency of remaining blood supply Administration of IV fluids (volume) inotrope therapy- dopamine, noradrenaline Fresh froxen plasma or whole blood

Question 55

Define hypervolemia

Answer 55

too much fluid in the blood increase in total sodium content which leads to increase in extracellular water.

Question 56

Etiologies of Hypervolemia

Answer 56

inability to regulate sodium (CHF, renal failure, Liver faiure etc) Exogenous sodium - IV solutions, medications such as mannitol Fluid mobilization after Burn injury

Question 57

Clinical features of Hypervolemia

Answer 57

``` Wt gain edema of LE and possibly UE Ascites Pulmonary Edema Nocturnal dyspnea JVD ```

Question 58

Diagnostic Findings of Hypervolemia

Answer 58

O2 sats low CXR showing pulm. cong. CBC levels -falsely low CMP- sodium BUN, potassium low , urine osmolality low

Question 59

Treatment of Hypervolemia

Answer 59

Treat the underlying cause - Sodium / H20 restrictions - Diuretics- loop recommended - NTG and morphine to vasodilate and reduce pulm cong. - Hydralazine/Captopril- reduce afterload - O2 suplementation - Hemodialysis