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86 Cards in this Set
- Front
- Back
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Total Body Fluid Varies According to...
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1. Muscle Mass
2. Electrolytes 3. Body Fat 4. Age 5. Gender |
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How much of our body does fluid comprise?
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60% male
50% female 77-80% infants and pediatrics |
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Body Fat & Fluid
As fat increases, what happens to water? |
As fat increases, water decreases.
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Gender & Fluid
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Women have more fat and lees fluid because of that than men.
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***Distribution of fluids can be...***
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* Intracellular Fluid Compartments
* Extracellular Fluid Compartments --------Interstitial --------Intravascular |
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***Intracellular***
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Inside the cell
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***Extracellular***
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Can be interstitial or intravascular.
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***Intravascular***
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In the veins and arteries but outside the cell.
Extracellular |
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***Interstitial***
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In between the tissue cells, not inside them.
Extracelluar |
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Total Body Water
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Intracellular - 66% of TBW
Extracellular - 34% of TBW ---------Interstitial - 75% ---------Intravascular - 25% |
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Edema
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The abnormal retention of fluid in the interstitial spaces of the extracellular fluid compartment or in serous cavities.
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Third spacing
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Aka Anasarca
third space fluid shift - Water, electrolytes & protein shift from the intravascular to the transcellular spaces |
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Transcellular Space
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The pericardial sac
The peritoneal sac The pleural cavity |
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Electroytes
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substances that dissociate in solution to form ions
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Ions
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positive or negatively charged particles-ideally equal in body
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Cation-positive ion (+)
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Sodium
Potassium Calcium Magnesium |
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Anion-negative ion (-)
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Chloride
Bicarbonate Phosphate Sulfate |
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***Na+
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135 to 145 mEq/L
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***K+
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3.5 to 5.0 mEq/L
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***Cl-
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95 to 105 mEq/L
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***Ca++
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8.5 to 10.5 mg/dl
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***Mg++
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1.8 to 3.0 mg/dl
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***Phosphorus
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2.4 to 4.1 mg/dl
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***Serum Osmolality***
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280 to 300 mOsm/Kg H20
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Diffusion
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Movement of PARTICLES (electrolytes) across a concentration gradient.
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Osmosis
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Movement of WATER across a semipermeable membrane from area of high concentration to low.
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Oncotic/Osmotic Pressure
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The pulling power of the solution to draw water across a semipermeable membrane.
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Isotonic solution
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same osmolality as body fluids
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Hydrostatic Pressure
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Pressure exerted by a fluid within a closed system on the walls of a container in which it is contained.
E.g the force exerted by blood against the vascular walls. |
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Oncotic pressure vs hydrostatic pressure
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ontcotic - the pulling pressure that keeps the pressure within the vascular space. It puts pressure on the outside walls of the vasculars.
Hydrostatic - Puts pressure on the inside walls of the vasculars from the intravascular fluids. There must be a balance between the two. |
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****Albumin****
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Albumin is the colloid (large molecule) plasma protein that maintains your colloid oncotic pressure
Maintains the fluid within the vascular space. Low albumin causes seepy capillaries and fluid is going to diffuse into the tissues. Colloid cause its a large molecule and it exerts a pulling pressure |
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Filtration
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Process where by fluid and solutes move together across a membrane from one compartment to another. The movement is from an area of higher pressure to one of lower pressure.
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Water Balance
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Goal is to have enough “effective circulating volume” to perfuse tissues
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Mechanisms to increase volume
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Thirst
ADH RAAS Atrial NatriureticPeptide |
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Normal Water Regulation
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Osmoreceptors in hypothalamus sense an increase in osmolality (more solutes).
Dehydrated Hypothalamus secretes hypothalamic-releasing hormones Stimulates the posterior pituitary to release ADH ADH increases renal water retention (raises BP) Osmolality returns to normal |
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*****Renin-Angiotensin Aldosterone System*****
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Main goal is to increase blood volume.
The juxtaglomerular cells (specialized nephrons) of the kidney sense a decrease in BP In response, kidney secretes renin (an enzyme). The renin stimulates angiotensinogin (a vasoconstrictor) to convert to angiotensin I. Angiotensin converting enzyme (in the lungs) then converts angiotensin I to Angiotensin II (Angiotensin II is a potent vasoconstrictor). The vasoconstrictor is now activated. Blood pressure increases due to vasoconstriction. Angiotensin II also stimulates the adrenal cortex/glands of the kidney to secrete aldosterone. Aldosterone signals the tubule of the kidney to hold on to (retain) sodium (and water). Therefore, there are 2 mecahnisms at work. One increases BP by vasconstricting the arteries while the other causes sodium retention (which increases water retention) to raise BP. |
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Angiotensin II
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Potent vasoconstrictor
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Normal urine pH
& Range |
6.0
4.6 to 8.0 |
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Normal urine specific gravity
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1.005 to 1.030
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Atrial Natriuretic Peptide
vs B-Type Natriuretic Peptide |
Both oppose renin.
Specific to heart muscle. When the heart is distended from too much fluid overload, ANP and BNP are released. Since they oppose renin, they will vasodilate the vessels and cause excretion of fluids. If a patient comes into the ER with fluid overload, BNP levels are checked. If BNP levels are elevated, we know they're in congestive heart failure (CHF). |
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Atrial Natriuretic Peptide
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Stored in cells of atria and ventricles
Opposes renin-angiotensin system Decreases blood pressure and volume |
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B-Type Natriuretic Peptide
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Stored mainly in ventricles
Levels correspond with heart failure Increases Glomerular Filtration Rate (GFR) due to vasodilation |
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Hypodipsia
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Decreased ability to sense thirst.
Elderly and stroke patients |
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Polydipsia
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Excess thirst.
Secondary to CHF or kidney disorder. May also be psychogenic |
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Diabetes insipidus
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Decreased ADH
NEUROGENIC Could be because the hypothalamus and pituitary are damaged (head trauma) OR NEPHROGENIC It could be that the kidneys are not responding to the ADH. |
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SIADH
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failure of the negative feedback system.
Chronic Acute |
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Hypovolemia (fluid volume defecit)
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Body loses both water and electrolytes from the extracellular fluid (ECF) in similar proportions
Loss of Water and Electrolytes from: 1. Vomiting 2. Excessive sweating 3. Polyuria (excessive urine production) 4. Fever 5. Nasogastric suction/Abnormal drainage/ wound losses Insufficient intake due to: 1. Anorexia 2. Nausea 3. Impaired swallowing, confusion, depression |
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2 Types of Fluid Imbalances
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1. Isotonic
2. Osmolar |
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Isotonic Fluid Imbalance
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water and electrolytes are lost or gained in equal proportions
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Osmolar Fluid Imbalance
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loss or gain of only water, thus osmolality of the serum is altered
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*****Clinical Manifestations of fluid volume deficit (FVD)*****
hypovolemia |
* Complaints of weakness and thirst
* Weight loss ------2% loss=mild FVD ------5% loss=moderate ------8% loss=severe * Decrease tissue turgor * Dry mucous membranes, sunken eyeballs, decrease tearing * Postural hypotension |
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Postural hypotension
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same as orthostatic hypotension
a fall in blood pressure associated with an upright position, usually occurring as a result of standing still for a long time or rising from a prolonged stay in bed and often causing faintness, dizziness, and vision disturbances. |
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Fluid Volume Excess (hypervolemia)
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The body retains both water and sodium in similar proportions to normal ECF.
Referred as hypervolemia. Due to: 1. Excess intake of sodium-containing intravenous fluids 2. Excess ingestion of sodium in diet or medications (antacids such as Alka-Seltzer) 3. Impaired fluid balance regulation related to: -----CHF -----renal failure -----cirrhosis of the liver |
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****Clinical Manifestations-FVE****
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* Weight Gain - over 24-48 hours
* Edema * Hypertension * Adventitious Breathe Sounds Crackles * Jugular Venous Distension (JVD) - with the bed at 30 degrees, you should not be able to see the patients jugular vein. |
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Serum Osmolality
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* A measure of the solute concentration of the blood.
* Normal value 280 to 300 mOsm/Kg * Increased serum osmolality indicates FVD * Decreased serum osmolality indicates FVE |
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Sodium (Na)
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* Most abundant cation in ECF
* Normal ranges 135-145 mEq/L * Major contributor to serum osmolality * Control and regulates water balance, acid-base balance, & nerve function (its a current carrying ion, carries nervous impulses) * Cl and water are reabsorbed with Na from the kidney tubules * Coupled with Cl and HC03 |
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Hyponatremia
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* Can be hypertonic or hypotonic
* Causes H20 to move out of the vascular space into the intersitital space and then into the intracellular space * Labs: Plasma sodium below 135 mEq/L Osmolality below 285 mOsm/kg Specific Gravity below 1.010 |
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Causes of Hyponatremia
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Excessive sweating and loss of sodium
GI suction Extreme Intake of salt free fluids Adrenal Insufficiency Head injury, stroke Diuretic therapy |
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****Clinical Manifestations Hyponatremia*****
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***FIRST SIGN IS AN ALTERED MENTAL STATUS (need Na for membrane potential in brain)***
Malaise, Muscle cramps Apprehension Abdominal cramps Nausea and Vomiting, Diarrhea Headache Confusion and Lethargy < 120 Convulsions and Coma |
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Hypernatremia
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* Excess Na+ in the blood plasma
* Increased extracellular osmotic pressure causes fluid to move out of the cells into the ECF * Cell become dehydrated * Water loss * Plasma Sodium exceed 145 mEq/L * Greatest in elderly and infants who can’t express thirst * Two Mechanisms: 1. Water Loss ------Metabolic-fever, exercise, diarrhea, tube feedings 2. Sodium Gain |
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******Clinical Manifestations of Hypernatremia******
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* Thirst
* Dry mucus membranes * Rapid, thready pulse * Hypotension * Oliguria * Confusion and Lethargy * Muscle weakness Twitching * Convulsions & Coma * Plasma Sodium exceed 145 mEq/L * Specific gravity of urine about 1.030 |
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***Potassium***
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* Major cation of intracellular fluid (ICF)
* Normal range 3.5-5.0 mEq/L * Dietary source (#1 bananas, peaches) * Regulated by kidneys -----Glomerular filtration (filtered by the kidneys at the entry port to the nephron) -----Aldosterone (regulates potassium elimination in the distal tubules of the kidney) -----Potassium/hydrogen ion exchange * Regulated by EC/IC shifts -----Insulin (Insulin also carries potassium into the cell. If patient is hyperkalemic, you give them insulin to drive the potassium into the cells). -----Acid-Base balance -----Exercise (muscle contraction increases potassium release) |
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What effect does exercise have on potassium?
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Muscle contraction increases potassium release
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What effect does insulin have on potassium?
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Drives potassium back into the cells.
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Potassium is responsible for...
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1. Osmotic integrity of cells
2. Acid-base balance 3. Conduction of nerve impulses 4. Controls excitability of skeletal, cardiac & smooth muscle ----Action potentials in the muscles (cardiac contraction is the most important) |
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Causes of Hypokalemia
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# 1 reason is inadequate intake because we do not store K+ very well.
Excess loss --Sweat --GI losses --Diuretics --Renal losses Transcellular losses --Insulin |
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****Hypokalemia Clinical Manifestations****
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* Muscle weakness + leg cramps
* Fatigue * Anorexia and Nausea & Vomitting * Decrease bowel sounds * Cardiac arrythmias (severe hypokalemia) * ECG: Prolonged PR Interval, flattened T, U wave, increased risk of ventricular arrhythmias ----- Effects conduction of the heart because the cardiac muscle is not able to repolarize. |
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Causes of Hyperkalemia
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* Renal Insufficiency
----Chronic Kidney Disease (CKD) ----Autoimmune nephropathy ----Acidosis ----Adrenal insufficiency ----ACEI/ARB’s (Ace Inhibitors & Angiotensin receptor blocking agents) - control BP (antihypertensive meds) and decrease aldosterone levels ----Potassium-sparing diuretics * ICF to ECF movement ----Potassium/Hydrogen Ion (as potassium levels go up, hydrogen ions increase too [acidosis]) * Excessive administration * RBC destruction - due to trauma or muscle damage. This increases potassium levels because it is released from the disrupted cells. |
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Hyperkalemia Clinical Manifestations
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* Generalized muscle weakness
* Respiratory muscle weakness * Paresthesis * EKG Changes: Peaked T Waves, Prolongation of PR Interval with Widening QRS, * V-fib & Cardiac arrest |
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Calcium
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* Normal Range: 8.5-10.5mg/dl (free active ionized calcium)
* Stored in bone, excreted by kidneys Functions: 1. Cation found in ICF 2. regulated by parathyroid hormone (PTH), vitamin D (helps make calcium more absorbable) and calcitonin (opposes it and uptakes calcium into the bone) 3. Transmission of nerve impulses 4. Contraction of cardiac muscle 5. Formation of bones & teeth 6. Coagulation process Calcium is found in largest quantity in body. 99% in bones (inactive form). Mobilized by parathyroid gland. Remaining 1 % in blood either bound to protein (albumin) or in active, ionized form Ca++ Very important in coagulation process…should always check albumin/Calcium |
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How is Calcium affected by
1. Acidosis 2. Alkylosis |
1. In acidosis - Ca++ is freed from albumin and therefore increased.
2. In alkalosis - Ca++ is decreased due to increased binding of Ca & albumin |
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Hypocalcemia Etiology
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Poor absorption
---GI ---Pancreatitis ---Vitamin D Hypoparathyroidism Hyperphosphatemia |
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***Hypocalcemia Clinical Presentation***
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Tetany -
-----Hyperreflexia (overactive neurological reflexes) -----Carpopedal spasm (spasms of the hands and feet), -----Cramps -----Laryngospasm (spasm of the larynx, the voice box). ***Trousseau Sign - when a BP cuff is inflated, the patient's hand spasms (carpul spasms), hand muscles contract. ***Chvostek Sign - when you tap the facial nerve, there is a transient paralysis of the jaw (facial muscle). Prolonged ST and QT Laryngeal stridor – patient with an obstructed airway, when u auscultate you hear a high pitched sound from a narrowed airway. Impaired Clotting Hypotension arrest |
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Hypercalcemia Etiology
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Increased bone release
----Immobility ----Fractures Hypophosphatemia Malignances - Malignant tumors release chemicals that cause CA release from bones Hyperparathyroidism Increased GI Absorption |
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Hypercalcemia Clinical Presentation
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Decreased LOC
EKG Changes (Calcium is a positive inotrope- increases strength of muscular contractions) Shortened ST segments Atrialventricular (AV) blocks Renal Calculi Bone Pain Fractures Calcification Band keratopathy - calcium deposits on the eye. |
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Magnesium
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We don't store it well
Normal Range:1.7-2.2mg/dl Functions: * Second most abundant Intracellular cation * Contracts the myocardium * Influences transport of Na/K across cells * Role in metabolism of carbs/proteins |
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Potassium and Magnesium relationship
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Low potassium = Low magnesium
Should supplement both |
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Hypomagnesemia Etiology
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Malabsorption
Alcoholism Diuretics |
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Hypomagnesemia Clinical Presentation
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Decreaded LOC
EKG changes Flat or inverted T waves Prolonged QT intervals Hyperreflexia Dysrythmias Similar to hypocalcemia |
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Hypermagnesemia Etiology
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Renal Failure
Excessive intake ---PO ---IV ---Laxatives |
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Hypermagnesemia Clinical Presentation
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#1 Cause is renal failure
EKG changes Peaked T waves Bradycardia Decreased LOC Decreased respirations Hyporreflexia - depresses CNS Basically slows everything down. Given to pregnant women for uterine contractions. |
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Phosphate
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* Normal Range: 2.5-4.5mg/dl
* 85% found in bones & teeth * Regulated by parathyroid * Needed for ATP! * Absorption takes place in GI, Jejunum * Influences absorption of glucose and needed for metabolism of carbs, protein, and fat. Functions: * Anion found highest in ICF * Bone & teeth formation * Nerve & muscle activity * Acid Base * Stores metabolic energy |
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Hyperphosphatemia Etiology
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Renal Failure
Excess intake -----Overadministration (IV, PO, Laxatives) Hypoparathyroidism Hypocalcemia |
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Hyperphosphatemia Clinical Presentation
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Hyperreflexia
S/S of hypocalcemia Phosphate deposits in joints |
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Hypophosphatemia Etiology
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Similar to hypomagnesemia...
Inadequate Intake ----Starvation ----Alcoholism Malabsorption Syndrome Hyperparathyroidism Renal Phosphate wasting - due to heavy metal poisoning |
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Hypophosphatemia
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Dyspnea - shortness of breath (SOB)
Muscle Weakness Confusion Decreased cardiac contractility |
