Fluid And Electrolyte

Question 1

Intracellular and Extracellular Fluid

Answer 1

2/3 is intracellular 1/3 is extracellular
Intracellular = potassium, magnesium (small amounts of sodium, chloride, bicarbonate, phosphate)
Extracellular = sodium and chloride (small amounts of bicarbonate, phosphate, calcium, magnesium, and potassium)
ICF and ECF always have equal amounts of cations and anions

Question 2

Edema: mechanisms of formation

Answer 2

I. Increase in capillary filtration pressure
Increased vascular volume - HF, kidney disease, IV overload
Venous obstruction - thrombophlebitis
Liver disease - portal vein obstruction
Acute pulmonary edema
Dependent edema

2. Decrease in capillary colloidal osmotic pressure
   Increased loss of plasma proteins - burns, kidney disease
   Decreased production of plasma proteins - liver disease, malnutrition
   General edema
3. Increase in capillary permeability
   Inflammation, allergic reactions, malignancy, ascites, pleural effusion, tissue injury, burns
   Localized non pitting
4. Produce an obstruction of lymph flow
   Malignant obstruction, surgery
   Localized to area of impaired drainage

Question 3

Edema: manifestations

Answer 3

Edema to brain, larynx, lungs, pericardial, pleural, peritoneum = life threatening

Joint spaces, coccyx, ankles, feet = discomfort, impaired rom

Tourniquet - blood vessel compression
Pressure ulcers - further for nutrients to diffuse
Psychological self concept

Non pitting edema = proteins accumulated in tissues and coagulated

Question 4

Edema: Treatment

Answer 4

elevation - counter gravity
Diuretic therapy - decrease fluid volume
Massage - promote lymphatic and vascular return
ROM - lymphatic and venous return
Serum albumin - given to IV to raise colloid plasma oncotic
Elastic support stockings - oppose fluid movement

Question 5

Third Space Accumulations

Answer 5

Loss or movement and trapping of ECF in trans compartment all spaces (serous, pericardial, peritoneal, pleural)
Cavities are often closely linked with lymphatic drainage

Milking action of moving structures (lungs) moves fluid and proteins back into lymphatic channels

Gain in body weight doesn’t contribute to fluid reserve or function

Hydrothorax - edema in the pleural cavity
Ascites - fluid in peritoneal cavity due to liver failure
Effusion - transmutation of fluid into serous cavities

Question 6

Water gain and water loss

Answer 6

Positive water balance = decreased osmolality and sodium
Negative water balance = increased osmolality and sodium

Gain - intake, metabolic processes
Loss - kidney, skin (insensible loss), lungs (insensible loss), GI

Question 7

Water Regulation

Answer 7

Aldosterone - increased sodium reabsorption and potassium excretion = increased blood volume
Renin, stress, trauma,
ADH - increases sodium reabsorption, aquaporins = increased blood volume
ECF volume and osmolality
Renin - angiotensin II = increased aldosterone, and sodium reabsorption = increased blood volume
Blood pressure low

Thirst and ADH regulate water intake and output

Question 8

Sodium Regulation

Answer 8

Sympathetic Nervous System: changes in arterial blood pressure = adjust in GFR and sodium reabsorption

RAAS - increase sodium reabsorption and vasoconstriction

Question 9

Thirst control

Answer 9

High osmolality = thirst and ADH release
Low osmolality = lack of thirst and decreased ADH release

Cellular dehydration (osmolality) and decrease in circulating volume (stretch receptors) stimulates hypothalamus to thirst and production of angiotensin II (nonosmotic thirst; back up)

Question 10

Hypodipsia and Polydipsia

Answer 10

Decreased ability to sense thirst
Commonly associated with lesions in the area of the hypothalamus (trauma, hemorrhage, meningiomas)

Excessive thirst
Inappropriate or false thirst - despite normal body water; CHF, chronic kidney disease
Compulsive water drinking - schizophrenia, smoking

Question 11

Diabetes Insipidus: Causes

Answer 11

Deficiency in ADH or a decreased renal response to ADH
Expelling large amounts of urine and excessive thirst
Danger arises when pt is unable to communicate need for water or unable to secure water

Neurogenic DI - deficit in synthesis or release of ADH
Inflammatory, autoimmune, vascular disease
Many have an incomplete form

Nephrotic DI - kidneys do not response to ADH
Congenital, pyelonephritis, lithium toxicity, electrolyte disorders

Question 12

Diabetes Insipidus: Manifestations

Answer 12

Intense thirst
Craving ice water
Polyuria
Reduced fluid volume
Polydipsia
Hypernatremia
Dehydration

Question 13

Syndrome of Inappropriate Antidiuretic Hormone: Causes

Answer 13

Failure of negative feedback system regulating ADH leading to water retention
Dilutional hyponatremia

Surgery, pain, stress, temperature changes, drugs, lung tumours, chest lesions, CNS disorders,
Tumors
Intrathoracic conditions - TB, pneumonia, positive pressure breathing

Question 14

SIADH: manifestations

Answer 14

Dilutional hyponatremia
Decreased urine output
Urine osmolality high
Hematocrit, serum sodium, BUN, decreased

Question 15

Isotonic Fluid Volume Deficit: Causes

Answer 15

Water and electrolytes lost in isotonic proportions

Severe vomiting
Diarrhea
GI suction
Excess urinary loss
Excess sweating
Endocrine disorders - adrenal insufficiency
3rd space losses

Question 16

Isotonic Fluid Volume Deficit: Manifestations

Answer 16

Decreased body weight
Thirst
Oliguria
Urine gravity increases 
Eyes look sunken
Tissue turgor decreases
BP decrease, HR increase, weak pulses
Postural hypotension

Hypovolemic shock
Vascular collapse

Question 17

Isotonic Fluid Volume Deficit: Treatment

Answer 17

Fluid replacement and measures to correct underlying cause

Question 18

Isotonic Fluid Volume Excess: Causes

Answer 18

Isotonic expansion of ECF - increase in total body sodium and body water

Excess intake of sodium
Heart failure - compensatory increase
Liver failure - impaired aldosterone metabolism
Corticosteroid hormone excess - increased reabsorption of sodium
Circulatory overload

Question 19

Isotonic Fluid Volume Excess: Manifestations

Answer 19

Weight gain
Dependent edema
Distended neck veins
Slow emptying peripheral veins
Full bounding pulse
Increased central venous pressures
Fluid accumulation in lungs - SOB, dyspnea, crackles, productive cough

Ascites
Pleural effusion

Question 20

Isotonic Fluid Volume Excess: Treatment

Answer 20

Sodium restricted diet

Diuretics

Question 21

Hyponatremia: Causes

Answer 21

Serum sodium below 135
Most common disorder

Hypertonic hyponatremia - hyperglycemia
Hypovolemic hypotonic hyponatremia - excessive sweating, GI fluid loss, adrenal insufficiency
Euvolemic hypotonic hyponatremia - SIADH
Hypervolemic hypotonic hyponatremia - HF, liver disease, renal failure, MDMA abuse

Question 22

Hyponatremia: Manifestations

Answer 22

Muscle cramps
Weakness
Fatigue
Nausea and vomiting
Abdominal cramps
Diarrhea
Apathy
Lethargy
Headache
Disorientation
Confusion
Depression of deep tendon reflexes
Seizure and coma 
Weakness

Question 23

Hyponatremia: treatment

Answer 23

Discontinue SIADH medication
IV or oral saline solution (hypertonic)
Loop diuretics
Vasopressin receptor antagonist

Question 24

Hypernatremia: Causes

Answer 24

Sodium above 145

Water loss through GI, urine, lungs, skin
Ingestion
IV sodium
Hypodipsia

Question 25

Hypernatremia: Manifestations

Answer 25

``` Thirst Tachycardia Decreased urine output Fever Flush warm skin Dry skin and mucous membranes Decreased salivation and lacrimation Decreased reflexes Agitation Headache Restlessness Seizure Coma ```

Question 26

Hypernatremia: treatment

Answer 26

Limit intake | Replace fluid oral or IV D5W

Question 27

Values of Co2, Bicarbonate, and pH

Answer 27

CO2 >50 = acidosis CO2 <35 = alkalosis PH <7.35 = acidosis PH >7.45 = alkalosis Bicarbonate <22 = acidosis Bicarbonate >36 = alkalosis Ph serum levels are not directly proportionate to CO2 levels Arterial blood gases - indicate respiratory and metabolic function

Question 28

Potassium Regulation

Answer 28

Intake oral urine output (aldosterone eliminates and hydrogen reabsorption eliminates) transcompartmental shifts in ICF and ECF Serum osmolality - water moves out of cell into ECF = increase in potassium concentration Acid base balance - cation shift for buffering pH = (alkalosis = hydrogen excreted; hypokalemia and acidosis = hydrogen reabsorbed; hyperkalemia) Insulin - temporary shift into cells; hypokalemia Sympathetic NS - epinephrine = increase in uptake; hypokalemia

Question 29

Hypokalemia: Causes

Answer 29

Serum potassium below 3.5 Inadequate intake - low potassium diet or inability to obtain or ingest food Burns and capillary injury Excessive renal losses - diuretic, alkalosis, magnesium depletion, increased aldosterone Insulin Beta adrenergic agonist drugs

Question 30

Hypokalemia: manifestations

Answer 30

``` Increased urine output - polyuria Nocturia Thirst Anorexia Nausea and vomiting Constipation Weakness Fatigue Muscle cramps ECG changes Arrhythmias and digitalis toxicity Alkalosis and renal chloride wasting ```

Question 31

Hypokalemia: treatment

Answer 31

Increasing intake Oral supplement IV potassium and magnesium replacement

Question 32

Hyperkalemia: causes

Answer 32

Potassium above 5 Decreased renal elimination - chronic kidney disease, nephropathy, aldosterone deficiency, potassium sparing diuretics, ace inhibitors Shift from ICF to ECF - acidosis, tissue injury, decreased insulin, beta blockers Increased intake

Question 33

Hyperkalemia: manifestations

Answer 33

``` Bradycardia Cardiac arrests ECG changes Weakness Paralysis Paresthesia Cramps Diarrhea Nausea and vomiting ```

Question 34

Hyperkalemia: treatment

Answer 34

``` Calcium Sodium bicarbonate Beta agonists Insulin Hemodialysis or peritoneal dialysis Restrict intake ```

Question 35

Hypocalcemia: causes

Answer 35

Below 8.5 ``` Decreased intake Renal failure Hypoparathyroidism Vitamin D deficiency Respiratory alkalosis Loop diuretic PPI H2 blockers Citrate ```

Question 36

Hypocalcemia: manifestations

Answer 36

``` Tetany Bone pain Carpopedal spasm Trousseau sign Chvoskek sign Twitching facial muscle Parestheisa Confusion Lethargy Anxiety Cardiac arrhythmia Resistance to digitalis Hypotension ```

Question 37

Hypercalcemia: Causes

Answer 37

Above 10.5 ``` Neoplasms of the parathyroid gland Hyperparathyroidism Immobilization Increased absorption in intestine Excess vitamin D Lithium Thiazide drugs ```

Question 38

Hypercalcemia: manifestations

Answer 38

``` Muscle weakness Lethargy Ataxia Personality changes Stupor Coma HTN ECG changes Anorexia Nausea and vomiting Constipation Thirst and dilute urine ```

Question 39

Carbon Dioxide Transport

Answer 39

Bicarbonate - plasma RBC, CA converts CO2 and H20 into H2CO3 that dissociates into H and HCO3 (bicarbonate) where HC03 is exchanged for Cl- Hemoglobin - combination of C02 and Hgb loose reversible for exchange in lungs Plasma - dissolved in plasma that forms carbonic acid from hydration of dissolved CO2

Question 40

Mechanisms of pH regulation

Answer 40

Chemical buffer - bicarbonate (weak acid H2C03 and weak base NaHC03) AND potassium hydrogen exchange AND body proteins Bone buffering - leading to demineralization Respiratory - ventilation to increase CO2 exchange; monitored by chemoreceptors in brain, carotid, and aortic bodies Renal - reabsorption of HCO3 and Regulation of H+ secretion and generation of new bicarbonate; phosphate buffer system

Question 41

Primary and Secondary in Mixed acid base disorders

Answer 41

Value furthest from norm is primary | If values of predicted compensatory values fall outside range it is mixed

Question 42

Metabolic Acidosis: causes

Answer 42

Increasing respiratory rate HCO3 <22 and pH <7.35 Lactic acid buildup and production of ketoacids Inadequate o2 deliver - shock, cardiac arrest, intense exercise, cancers, liver failure Poorly controlled diabetes Kidney disease Diarrhea

Question 43

Metabolic Acidosis: manifestations

Answer 43

``` Lethargy Stupor Fatigue and malaise Kussmauls respirations Hyperventilation Hypotension Arrhythmia Tachycardia Anorexia Nausea and vomiting Abdominal pain ```

Question 44

Metabolic Acidosis: treatment

Answer 44

Correcting underlying cause Restoring lost fluid and electrolytes Insulin and fluid replacement in diabetic ketosis

Question 45

Metabolic Alkalosis: causes

Answer 45

Hypoventilation HCO3 >26 ph >7.45 ``` Vomiting Gastric suctioning Ingestion of alkali - calcium carbonate, antacids IV bicarbonate Hyperaldosteronism Diuretics Abrupt acidosis correction ```

Question 46

Metabolic Alkalosis: manifestations

Answer 46

``` Hyperactive reflexes Tetany Confusion Seizures Carpopedal spasm Trosseau signs Bradypnea Shallow respirations Hypoxemia Respiratory acidosis Hypotension Arrhythmia Nausea and vomiting ```

Question 47

Metabolic Alkalosis: treatment

Answer 47

Correcting underlying cause | Chloride Deficit requires correction (potassium chloride)

Question 48

Respiratory Acidosis: causes

Answer 48

Renal adaptation PaCO2 >45 pH <7.35 ``` Acute respiratory failure Narcotic overdose Lung disease Chest injury or obstruction Pneumothorax Enervation COPD Timor Exercise Fever - Hyperthermia Sepsis Burns Carbohydrate rich diet Accidental inspiration of CO2 ```

Question 49

Respiratory acidosis: manifestations

Answer 49

``` Restlessness Confusion Depressed reflexes Somnolence Coma Blurred vision Psychological disturbances Dyspnea Tachypnea Hypoxemia Tachycardia Arrhythmia HTN or Hypotension Warm flush skin and weakness ```

Question 50

Respiratory acidosis: treatment

Answer 50

Improve ventilation | Mechanical ventilation

Question 51

Respiratory alkalosis: causes

Answer 51

Hydrogen pulled from cells to produce carbonic acid PaCO2 <35 and pH >7.45 Hyperventilation Medullary stimulation Mechanical ventilation Disease processes

Question 52

Respiratory alkalosis: manifestations

Answer 52

``` Dizzzy, Agitated Circumoral and peripheral paresthsia Tetany Twitching Muscle weakness Light headed Deep rapid respirations Dyspnea Palpitations Tachycardia ```

Question 53

Respiratory alkalosis: treatment

Answer 53

Correct underlying cause Rebreathe into a paper bag Supplemental o2 and changing ventilator settings