Volume Contraction means decrease in total body water.  What are the 3 subclassifications based on alterations in ECF?

1. Isotonic contraction

2.  hypotonic contraction

3.  hypertonic contraction

Volume Expansion means increase in total body water.  What are the subclassifications?

1.  Isotonic expansion

2.  Hypotonic expansion

3.  Hypertonic expasion

What are the two abnormal states of hydration?

1.  Volume Contraction

2.  Volume Expansion

What is isotonic contraction?

What causes it?

How do you treat it?

Volume contraction but no change in osmolality.

Causes:  Diarrhea, vomiting, kidney disease, misuse of diuretics.

Treatment:  Isotonic Fluids - 0.9% NSS

What is hypertonic contraction?

What causes it?

Hoiw do you treat it?

Volume contraction - loss of water exceeds loss of Na.  Loss of water AND increase in osmolality.

Causes:  excessive sweating, osmotic diuresis, feeding excessively concentrated foods to infants, extensive burns

Tx:  Hypotonic Fluids - 0.11 NSS or no solutes at all.

What is hypotonic contraction?

What causes it?

How do you treat it?

Loss of Na exceeds loss of water.

Exccessive loss of Na throught he kidneys due to diuretic therapy, chronic renal insufficiency, or lack of aldosterone.

Tx:  If hyponatremia is mild and kidneys functioning, treat with isotonic NaCl IV.

If hyponatremia is severe, a hypertonic 3% solution of NaCl should be infused.

What are thre three types of Volume Expansion?

1.  Isotonic

2.  Hypotonic

3.  Hypertonic

What is the cause of volume expansion? 

Overdose with therapeutic fluids, or associated with disease states such as HF, nephrotic syndrome, or cirrhosis of the liver with ascites

What drugs are used to treat volume expansion?

Diuretics and agents used for HF.

What are the  4 types of acid-base disturbance?

Respiratory acidosis

Respiratory alkalosis

Metabolic acidosis

Metabolic alkalosis

What are the systems that regulate acid-base balance?

1.  bicarbonate-carbonic acid buffer system

2.  respiratory system

3.  the kidneys

What causes respiratory alkalosis?

How do you treat it?

mild hyperventilation may be caused by hypoxia, pulmonary disease and drugs, especially ASA and other salicylates.

Severe hyperventilation can be caused by CNS injury and hysteria

Tx:  dictated by severity of pH elevation

Mild - no specific tx is indicated.

Severe - rebreath into a brown bag and a sedative

What causes respiratory acidosis?

How do you treat it?

Retention of CO2 secondary to hypoventilation caused by depression of medullary respiratory center, pathologic damages in the lungs (asthma, obstruction). 

Tx:  over time, the kidneys secrete less bicarb to accomodate; FIRST, correct respiratory impairment; oxygen and vent assistance.  Infusion of sodium bicarb may be indicated if severe enough.

What is metabolic alkalosis? 

What causes metabolic alkalosis?

How do you treat it?

increases in both the pH and bicarbonate level

causes:  excessive loss of gastric acid (thru vomiting or suctioning). 

Tx:  Body compensates:  hypoventilation - increases CO2; increased renal excretion of bicarb and acdumulation of organic salts. 

Tx withIV NaCl + KCl which facilitates renal excretion of bicarb. 

What is the role of K in the ECF?

Major role in conducting nerve impules and maintaining electrical excitability of muscle.  Also helps regulate acid-base balance

What is the most common cause of hypokalemia?

Treatment with thiazide or loop diuretic.

Also, insufficient K+ intake, alkalosis and insulin which both drive K+ into the cell.

What are the S&S's of Hypokalemia?

How do you treat it?

Impacts skeletal muscle, smooth muscle, bp, and heart.

Muscle weakness, risk of fatal dysrythmias, intestinal dilation and ileus.

KCL supplement, IV if severe

What is the principle cause of digoxin toxicity?

Hypokalemai

What are the casuses of hyperkalemia?

How do you treat it?

Severe tissue trauma, untx'd Addison's Disease, Acute acidosis (draws K+ out of cell), misuse of K+ sparing diuretics, overdose with IV K+.

Tx:  Withhold meds that contain or accumulate K+

Infuse a calcium salt to offsett cardiac effects of K+, infuse glucose and insulin to promote K_ uptake by cells, and infuse Na HCO3 if acidosis is present.

What are the S&S's of hyperkalemia

Disruption with electrical activity of heart, v-tach, v-fib, and cardiac arrest

Also confusion, anxiety, dyspnea, weakenss or heaviness of legs.