Flid and Electrolyte/Acid-Base Imbalances

Fluid Volume Deficit

Fluid Volume Deficit

• ECF water loss

• Intake < Output

Fluid Volume Deficit Causes

• Severely decreased oral intake of water and salt.

• Increased GI output: vomit, laxative overuse, etc.

• Loss of blood or plasma.

Fluid Volume Deficit Signs and Symptoms

• Sudden weight loss

• Thirst

• Restlessness

• Confusion

• Hypotension

• Oliguria

• Hypovolemic shock

Fluid Volume Deficit Lab Values

• Hematocrit Increases

• BUN Increases

• Specific Gravity Increases

Fluid Volume Excess

• ECF water gain

• Intake > Output

Fluid Volume Excess Causes

• Excessive administration of IV fluids or water and salt.

• Renal retention of Na+ and water:

  • Heart failure

  • Cirrhosis

  • Renal disease

  • Aldosterone or glucocorticoid excess

Fluid Volume Excess Signs and Symptoms

• Sudden weight gain (overnight)

• Confusion

• Edema

• Crackles in the lungs

• Pulmonary edema

Fluid Volume Excess Lab Values

• Hematocrit decreases

• BUN decreases

• Specific Gravity decreases

Hyponatremia

Diluted body fluid

Hyponatremia Causes

• Excessive ADH

• Polydipsia or forced excessive water intake

• Tap-water enemas

• Excessive IV administration of D5W

• Replacement of a large body fluid output with water but no Na+

Hyponatremia and Hypernatremia Signs and Symptoms

• Decreased LOC

• Confusion

• Coma

• Thirst

• Seizures

• Lethargy

Hyponatremia Lab Values

• Na+ < 136 mEa

• Serum osmolality <285 mOsm/kg

Hypernatremia

Concentrated body fluids

Hypernatremia Causes

• Diabetes insipidus

• Osmotic diuresis

• Lack of access to water

• Large insensible perspiration

Hypernatremia Lab Values

• Na+ >145 mEq/L

• Serum osmolality: >295 mOsm/kg

Clinical Dehydration

Fluid volume deficit + Hypernatremia

Clinical Dehydration Causes

• All causes of ECV deficit along with poor or no water intake often with a fever causing increased insensible water output.

Clinical Dehydration Signs and Symptoms

• Combination of ECV deficit and hypernatremia findings

K Normal Value

3.5-5.0 mEq/L

K Function

• Maintains resting membrane potential skeletal, smooth, and cardiac muscle allowing for normal muscle function

K Food Sources

• Fruits

• Potatoes

• Instant coffee

• Molasses

• Brazil nuts

Hyperkalemia Causes

• Increased K intake and absorption

• Oliguria

Hyperkalemia Signs and Symptoms

• Muscle weakness

• Cardiac dysrhythmias

• Cardiac arrest

Hypokalemia Causes

• Diarrhea

• Vomiting

• K wasting diuretics

Hypokalemia Signs and Symptoms

• Muscle weakness

• Cardiac dysrhythmias

• Paralysis

Ca Normal Value

9.0-10.5 mg/dL

Ca Function

• Influences excitability of nerve and muscle cells

• Necessary for muscle contraction

Ca Food Sources

• Dairy products

• Canned fish with bones

• Broccoli

• Oranges

• Requires vitamin D for best absorption

Hypercalcemia Causes

• Increased Ca intake/absorption

• Some cancers draw Ca out of the bones

• Bone injuries

Hypercalcemia Signs and Symptoms

• Decreased neuromuscular excitability

• Increased lethargy

Hypocalcemia Causes

• Low Ca concentration in the blood

• Commonly seen in pancreatitis patients

Hypocalcemia Signs and Symptoms

• Hyperactive reflexes

• Numbness/tingling of fingers

• Tetany

• Chvostek’s sign

Mg Normal Value

1.3-2.1 mEq/L

Mg Function

• Influences function of neuromuscular junctions

• Cofactor for numerous enzymes

Mg Food Sources

• Dark leafy greens

• Whole grains

• Some laxatives and antacids

• Undigested fat proteins prevents absorption

Hypermagnesemia Causes

• End-stage renal disease

Hypermagnesemia and Hypomagnesemia Signs and Symptoms

• Lethargy

• Decreased neuromuscular excitability

• Decreased tendon reflexes

Hypomagnesemia Causes

• A shift to Mg’s inactive bound form

Phosphate Normal Value

3.0-4.5 mEq/L

Phosphate Function

• Produces ATP

Phosphate Food Sources

• Milk

• Processed foods

• Beans

• Dark leafy greens

Metabolic Acidosis Causes

• Ketoacidosis:

  • Diabetes

  • Starvation

  • Alcoholism

• Hypermetabolic state (burns)

• Oliguric renal disease

• Ingestion of acid or acid precursors

• Diarrhea

• Pancreatic fistula

• Renal tubular acidosis

Metabolic Alkalosis Causes

• Excessive sodium bicarbonate administration

• Massive blood transfusion

• Mild or moderate ECV deficit

• Excessive vomiting or gastric suctioning

• Hypokalemia

• Excessive aldosterone

True

True or False: The entire GI tract is lined with K and the bowels are lined with bicarb.

Respiratory Acidosis Causes

• Type B COPD

• Airway obstruction

• Bacterial pneumonia

• Excessive atelectasis

• Severe acute asthma episode

• Respiratory muscle weakness/fatigue

• Chest wall injury or painful surgery

• Drug overdose

• Some types of head injuries

Respiratory Alkalosis Causes

• Hypoxemia

• Acute pain

• Anxiety, psychological distress, sobbing

• Inappropriate mechanical ventilator settings

• Simulation of respiratory control in the brainstem (Ex. Sepsis, meningitis, head injury, aspirin overdose)

Respiratory Acidosis Lab Values

• pH: Below 7.35

• PaCO2: Above 45 mmHg

• HCO3: 21-28 mEq/L

• Retention of CO2

Respiratory Acidosis Signs and Symptoms

• Headaches

• Light-headedness

• Decreased LOC

• Dysrthymias

Respiratory Alkalosis Lab Values

• pH: Above 7.45

• PaCO2: Below 35 mmHg

• HCO3: 21-28 mEq/L

• Blowing off CO2

Respiratory Alkalosis Signs and Symptoms

• Lightheadedness

• Numbness

• Increased rate and depth of respirations

• Excitement/confusion followed by a decreased level of consciousness

• Dysrhythmias

Metabolic Acidosis Lab Values

• pH: Below 7.35

• PaCO2: 80-100 mmHg

• HCO3: Below 21 mEq/L

Metabolic Acidosis Signs and Symptoms

• Decreased LOC

• Abdominal pain

• Dysrhythmias

• Increased rate and depth of respirations

Metabolic Alkalosis Lab Values

• pH: Above 7.45

• PaCO2: 80-100 mmHg

• HCO3: Below 21 mEq/L

Metabolic Alkalosis Signs and Symptoms

• Light-headedness

• Numbness

• Muscle cramps

• Possible excitement and confusion followed by decreased LOC

• Dysthymias

pH Normal Value

7.35-7.45

PaCO2 Normal Value

35-45 mmHg

HCO3 Normal Value

21-28 mEq/L