NURS 115 TEST FOUR STUDY GUIDE:
RENAL FUNCTION:
Terms to Know:
1. Enuresis: condition of urine – bed wetting
2. Glomerular Filtration Rate (GFR): measure how well the kidneys are functioning
3. Loop of Henle: long U-shaped portion of the tubule that conducts urine within each
nephron of the kidney
4. Renal Clearance: volume of plasma completely cleared of a substance by the kidneys
per unit time. A higher renal clearance suggests the substance may be cleared
almost completely in one pass through the kidneys while a low value describes a
substance that may not be eliminated by the kidneys at all.
5. Turbidity: the quality of being cloudy, opaque, or thick with suspended matter.
FUNCTION OF GLOMERULUS, LOOP OF HENLE
-Glomerulus:
High pressure capillary filtration system – between two arterioles (2-3 times high
than other capillaries)
Afferent arteriole – from the renal artery
Efferent arteriole – to the peritubular capillary vessels
Surrounded by thin-walled Bowman’s capsule
-Glomerular Filtrate Rate (GFR)
Capillary filtration pressure – how much pressure can push out into the beds;
effect GFR
Osmotic Pressure – effects concentration; how stuff is in there
Capillary Permeability – how holy are your capillaries – a lot of pressure = holier
Filtrate is similar to plasma – no large proteins
Approximately 125 ml/minute – variable
Creatine:
Produce of creatine metabolism in the muscle
Filtered by the kidneys BUT NOT reabsorbed
Best way to measure kidney function
Creatinine clearance used to measure GFR
24-hr urine collection
Two 1 hour urine specimens are collected with blood drawn in between
-Glomerulus produces an “ultrafiltrate of urine”
-Tubules:
Reabsorb electrolytes, water, nutrients to maintain homeostasis, Na, K, Ca
Eliminates waste materials, excess
COMMON LAB & DIAGNOSTIC TEST FOR RENAL FUNCTION
-UA: urinary analysis
Clear, amber-colored fluid
Approximately 95% water and 5% dissolved solids
The kidneys normally produce approximately 1.5 L of urine each day
Contains metabolic wastes and few or no plasma proteins, blood cells, or glucose
molecules
A minimum of 30 mL per hr of urine then you have some issue; either you are
not hydrated, or the kidneys are not making urine like they should
-GFR: urine test:
A blood test measure how much blood your kidneys filter each minute (GFR)
RENIN RELEASE & RAAS
-The Renin-Angiotensin-Aldosterone Mechanism RAAS:
Plays important part in regulation of blood pressure
is the release of the enzyme renin. Renin released from granular cells of
the renal juxtaglomerular apparatus (JGA) in response to one of three
factors: Reduced sodium delivery to the distal convoluted tubule detected
by macula densa cells
ERYTHROPOIETIN
-Regulates the differentiation of red blood cells in bone marrow
DIURETICS, CLASSES, TYPES, USE:
- LOOP: WORK IN LOOP OF HENLE; K WASTING DIURETIC
Exert their effect in the thick ascending loop of Henle
Most effective diuretics agents
Reduces reabsorption of Na, K, Cl and increases elimination of Ca and Mg
Difficult to concentrate urine (looks like water)
- THIAZIDE: DIURETICS
Prevent the reabsorption of NaCl in the distal convoluted tubule; K wasting
diuretics
Less effective because of site of action
Potassium wasting causes peripheral vascular resistance – first line drug for HTN
- ALDOSTERONE AGONIST – work against aldosterone – retain Na in the water so it will be
antagonized – it will get dump (na) you are now holding a lot of K. it is a K sparing
diuretic
(potassium-sparing diuretics – spironolactone
Less effective than others
Metabolic acidosis sometimes seen
Reduce sodium reabsorption and increases potassium secretion in the late distal
tubule and cortical collection tubule site regulated by aldosterone
SPECIFIC GRAVITY OF URINE, OLIGURIA:
-Specific gravity high – dehydration
-Specific gravity low – dec renal function (can’t concentrate the urine) – kidney that does
work
-Presence of RBCs, WBCs, bacteria, casts, crystals protein molecules, glucose, ketones,
etc.
Know Labs such as Creatinine, BUN as Related to Renal Function
- CREATININE:
Reflects GFR
Formation and release is relatively constant
Freely filtered in the glomeruli
Not absorbed back into the blood
Not much secreted back into the tubules
Normal range: creatinine -0.6 to 1.2 mg/dL
May need to be adjusted for age
Related to loss of muscle mass and renal function
Strong relationship between renal function and creatinine level
If creatinine is 2X normal = loss of ½ renal function
3X normal = loss of ¾ of renal function
Levels at 10 mg/dL or more = loss of 90% of renal function
- BUN: BLOOD UREA NITROGEN
By-product of protein metabolism
Eliminated entirely by the kidneys
Levels may be affected by: protein intake, GI bleed, dehydration
2/3rds of renal function MUST be lost before you see an increase in BUN
Normal range – 8.0 to 20.0 mg/dL
Creatinine – 0.8 to
- BUN-CREATININE RATIO:
BUN not very specific for renal problems
But when compared with creatinine – BUN-Creatinine ratio
>15:1 = pre renal cause of failure – CHF, upper GI bleed
<10:1 = liver disease, dialysis , low protein diet
FLUIDS AND ELECTROLYTES:
Know all electrolytes – what they do – functions, levels, where they primarily lives; know all
fluid compartments: ICF, ECF, etc.:
-Cations (+): sodium, potassium, calcium, magnesium
-Anions (-): chloride, bicarbonate, phosphate/phosphorus
-Intracellular Fluid Electrolytes: potassium, phosphorus, magnesium
-Extracellular Fluid Electrolytes: sodium, chloride, calcium, and bicarbonate
-ECF – _EXTRAcellular_ Fluid
-fluid outside of the cell,
-Either _interstitial_ (in between tissues)
-or __intravascular__ (within the vessel)
-ICF – _INTRAcellular_ Fluid
-Fluid “within” or inside the cell
-ECF and ICF are separated by capillaries and membranes
- SODIUM: 135-145 mEq/L:
Controls body water distribution and governs osmolarity (solute to water ratio)
Controls water distribution by osmosis
Facilitates transmission of nerve and muscle impulses through Na-K pump
Regulation of Acid-Base balance Na + Cl and bicarbonate (HCO3) changes pH
Ingested n most foods and liquids
IV fluids
Thirst controls water intake (Na follows water)
- POTASSIUM: 3.5-5 mEq/L:
Regulates cell excitability (skeletal muscle contraction)
Permeates cell membranes, affecting the cell’s electrical status (heartbeat and
nerve conduction) by maintaining neutrality
Helps control ICF osmolality (concentration of a solution = to the solute to water
ratio)
Intake in the diet, need 40 mEq daily – bananas, oranges, strawberries, potato
skin
If a patient is already taking an aldosterone antagonist, they are already holding
potassium
- SODIUM, POTASSIUM AND WATER BALANCE
Think “Sodium” – think “water”
A sodium level reflects the relationship between sodium and water
Regulation of water balance – gains and losses
Mechanisms of water regulation ADH
Decreased Na+ (water gain)
↓
Serum osmolality falls
↓
Thirst diminishes, decrease in water intake
↓
ADH is suppressed
↓
Renal excretion increases
Serum osmolality normalizes
Increased Na+ (water loss)
↓
Rise in serum osmolality
↓
Thirst increases, drink more water
↓
ADH release increases
↓
Renal excretion decreases
Serum osmolality normalizes
RELATIONSHIP BETWEEN CALCIUM & POTASSIUM:
-Intracellular fluid – K major electrolyte – fluid within billions of cells in the body (2.3 of
fluid)
-Extracellular Fluid – Na major electrolyte – fluid in interstitial, tissue spaces and blood
vessels includes plasma
- CALCIUM: 8.5 – 10.5 mg/dL
Major cation in teeth and bones (99%)
Found in cell membranes – help them keep their shape
Functions:
1. Helps muscles contract
2. Aids in coagulation
3. Increases skeletal muscle contraction
4. Increases cardiac muscle contraction – slows down repolarization
5. Regulates nerve impulse transmissions
6. Assist in blood clotting
7. Provides bone strength and density
Balance: role of vitamin D and parathyroid hormone
1. Hypoparathyroidism =
2. Hyperparathyroidism =
Intake: dietary
1. Milk and dairy products – 800-1000 mg/day
Phosphorus inversely follows calcium
- MAGNESIUM: 1.8 – 3.0 mg/dL
In ICF, after K
1. Stimulates and skeletal muscle contractions
2. Participates in carbohydrate and protein metabolism
3. Activates B complex vitamins and ATP
Enhances protein and DNA synthesis
Facilitates transportation of Na and K across cell membranes
Influences intracellular Ca through effect on PTH: low Mg impairs action of PTH
- CHLORIDE: 98 -106 mEq/L “the tag along electrolyte”
Negatively charged (anion)
Assists in the conduction of nerve and muscle transmissions
Binds with hydrogen in the stomach to make hydrochloric acid
Maintains fluid in blood vessels
- PHOSPHORUS: 2.5 – 4.5 mg/dL
Largely an ICF anion
Incorporated into nucleic acids and ATP
Phosphate excess occurs with renal failure and PTH deficit
Associated with decrease calcium levels
Essential in bone formation
1. Ingested in diet: milk and meats
Metabolic processes – metabolism of fat, glucose, protein
Incorporated in cells: DNA, RNA, and phospholipids layer of cell membranes
Serves as acid base buffer in the ECF and in renal excretion of hydrogen ion
Needed for normal RBC, WBC and platelet function
Know about sensible/insensible water loss:
- SENSIBLE FLUID LOSSES: refer to typical routes of excretion such as urination and
defecation.
- INSENSIBLE FLUID LOSS: refer to other routes of fluid loss such as in sweat and from
respiratory tract
SYMPTOMS OF FLUID OVERLOAD
1. Rapid weight gain
2. Edema in arms, legs, and face
3. Swelling in abdomen
4. Cramping, headache, and stomach bloating
5. Shortness of breath
6. High blood pressure
7. Heart problems – including congestive heart failure
DIFFERENCE OF WATER IN THE BODY OF MALES AND FEMALES:
-Women, obese persons typically have lower water content
-Decreases as we get older – after age 60, your water content drops to about 45%
HYPOVOLEMIA/HYPERVOLEMIA:
-Abnormal decrease in the volume of blood plasma. Hypovolemia occurs with
dehydration or bleeding.
-also known as fluid overload, is the medical condition where there is too much
fluid in the blood. The opposite condition is hypovolemia, which is too little fluid
volume in the blood.
Condition Problem Causes
Hypovolemic Water loss to lesser amount and Na loss diarrhea, vomiting,
diuretic use, sweating
Euvolemic Retention of water /dilution of Na-
Normal ECF volume
SIADH or
Thirst disorder
Hypervolemic ↑ECF volume Edema forming
– CHF, cirrhosis,
kidney disease
- HYPONATREMIA:
Cause: due to gain of water or loss of Na; Sodium less than <135 mEq/L
Manifestation: sodium dilation
Treatment: limit water intake, and discontinue the medication that contribute to
SIADH; administer saline solution orally or IV
Hypertonic Hyponatremia:
Osmotic shift from ICF to ECF
Hyperglycemia: osmotic effect of glucose on the cells
Na becomes dilute as water moves out of the cells into the ECF – diluting
the concentration of Na
Hypotonic (Dilutional) Hyponatremia:
Water retention – decrease in serum osmolality
Decrease in Na concentration and tonicity of ECF
- HYPERNATREMIA: >145 MEQ/L
Cause: excessive water loss, decrease water intake, excessive sodium intake
Manifestations: laboratory values, thirst and signs of increased ADH levels,
intracellular dehydration
Treatment: physical examination finding indicative of dehydration, and results of
laboratory tests. Measuring the underlying cause to treat the accompanying
dehydration
- HYPOKALEMIA:
Cause: inadequate intake, excessive renal loss, excessive GI loss,
transcompartmental shift
Manifestations: laboratory value: serum K level below 3.5 mEq/L, impaired
ability to concentrate urine, GI manifestation (constipation, abdominal
distention), neuromuscular manifestations, cardiovascular manifestations, CNS
manifestations, acid-base disorders
Treatment: intake of high K foods, oral K supplements, through IV, be careful if
one has low K they most likely have low Mg
- HYPERKALEMIA:
Cause: excessive intake, release from intracellular compartment, inadequate
elimination by kidneys
Manifestation: laboratory values: K lvel above 5.0 mEq/L, GI manifestations,
neuromuscular manifestations, cardiovascular manifestations.
Treatment: varies with degree of increase in plasma K whether there are ECG
and neuromuscular manifestations
- HYPOCALCEMIA:
Cause: impaired ability to mobilize, decrease intake or absorption, abnormal
renal loss, increased protein binding, and increased sequestrant
Manifestation: laboratory values: Ca level below 8.5 mg/dL, neuromuscular
manifestations, cardio manifestations (hypotension, failure), skeletal
manifestations (osteomalacia, bone pain, fractures)
Treatment: IV containg Ca, or oral intake
- HYPERCALCEMIA:
Cause: increased intestinal absorption, increased bone resorption, decreased
elimination
Manifestation: laboratory values: 10.5 mg/dL, impaired ability to concentrate
urine and exposure of Kidney to increased concentration of calcium (polyuria,
polydipsia), anorexia, nausea, muscle weakness, loss of muscle tone, osteopenia,
osteoporosis, lethargy, hypertension
Treatment: rehydration and use of measure to increase urinary excretion of
calcium. Fluid replacement is needed sometimes
- HYPOMAGNESEMIA:
Cause: impaired intake or absorption, increased losses
Manifestation: lab values: below 1.8 mg/dL, personality change, nystagmus,
tetany, tachycardia, hypertension, cardiac arrhythmias
Treatment: treated with Mg replacement
- HYPERMAGNESEMIA:
Cause: excessive intake, decreased excretion
Manifestation: lab values: above 3.0 mg/dL, lethargy, hyperlexia, coma,
confusion, hypotension, cardiac arrest, cardiac arrhymias
Treatment: cessation of Mg administration. Ca is used as an antagonist
- HYPOPHOSPHATEMIA:
Cause: decreased intestinal absorption, increased renal elimination, malnutrition
and intracellular shifts
Manifestations: lab values: below 2.5 mg/dL in adults 4.0 in children, intention
tremor, seizures, muscles weakness, joint pain, hemolytic anemia, impaired WBC
function
Treatment: directed towards prophylaxis, dietary sources, oral or IV
- HYPERPHOSPHATEMIA:
Cause: acute phosphate overload, intracellular-to-extracellular shift, impaired
elimination
Manifestations: lab value: above 4.5 mg/dL in adults 5.4 mg/dL in children,
parathesis, tetany, hypotension, cardiac arrhythmias
Treatment: directed at the cause of the disorder, dietary restriction of foods of
high phosphorus
-TROUSSEAU’S SIGN: DECREASE IN CA, MG
-Ischemia-induced carpal spasm
-Hypocalcemia
-Hypomagnesemia
-Neuromuscular irritability
-Occurs during taking BP
-Flexion contractor
Low levels of Ca and Mg
-CHVOSTEK’S SIGN: DECREASE CA
-Facial irritability
-Low calcium
-Unilateral spasm induced by tap over the facial nerve CN 7
-Associated with hypocalcemia
Know about third spacing/edema:
- THIRD SPACING:
when fluid moves out of the intravascular (part of the ECF), but NOT into the
intracellular space
results from an increase in permeability of the capillary membrane or a decrease
in plasma colloid osmotic pressure
fluid re-locates in areas of the body such as:
peritoneal cavity – ascites
pericardiac sac, pleural cavity – effusions
fluid attributes to weight
does not attribute to fulfilling need for fluid or function
- EDEMA:
Increased capillary pressure
Decreased colloidal osmotic pressure
Increased capillary permeability
Obstruction of Lymphatic Flow
Manifestations of Edema:
May be life threatening – brain, lung, larynx
May limit movement
May limit movement
May impede blood flow to muscle or viable tissue – surgical correction if needed
Pitting edema
Assessment and Treatment of Edema:
Assessments:
Daily weights
Measure girth of effected limb – same location – same time of day each day
Visual inspection
Finger pressure to determine if pitting edema – graded 1+ to 4+
Treatment – correct the cause: compression socks, elevation, diuretics
IV fluid types and capillary pressures:
CAPILLARY INTERSTITIAL FLUID EXCHANGE:
- CAPILLARY FILTRATION PRESSURE: IN CAPILLARIES DEALS WITH FILTRATION
Results from blood pushing against the walls of the capillary
- INTERSTITIAL HYDROSTATIC PRESSURE: IN THE INTERSTITIAL FLUID
Fluid that is stuck and is not moving; if you have lots of capillary filtration
pressure
When the pressure inside a capillary is greater than the pressure in the
surrounding interstitial space, fluids and solutes inside the capillary are
forced in the interstitial space and vice versa
- CAPILLARY COLLOIDAL OSMOTIC PRESSURE: IT’S A PULL PRESSURE
You have to have a stuff (solutes) in the vessels
This process, known as reabsorption, prevents too much fluid from
leaving the capillaries.
_Albumin acts as a magnet to attract water and hold it inside of the blood
vessel
Excess fluid shifts are picked up by the lymphatics and returned to the
heart for circulation
-You never do a blood pressure on the affected side of the women who has had surgery
for breast cancer
NEURO FUNCTION & DISORDERS:
CVA – ISCHEMIC VS HEMORRHAGIC, RISK FACTORS, TREATMENTS
•Sudden impairment of cerebral circulation
•Affects one or more of the blood vessels that supply the brain
•interrupts or diminishes O2 supply, causing serious damage or necrosis in the brain
tissues.
Cause:
•thrombosis__ : obstruction in the extracellular vessels
•____embolism____ : occlusion by clot, tumor, plaque, fat
•____hemorrhage______ : from chronic HTN or aneurysms
Risk Factors:
•History of TIA
•Atherosclerosis
•HTN
•Arrhythmias, especially AF
•Rheumatic heart disease
•Elevated triglyceride levels
•Lack of exercise
•Hormonal contraceptive use
•Drug abuse
•Smoking
•Family Hx of CVA
Diagnosis:
•Careful history taking & evaluation of coexisting diseases
•Neurological examination
•CT, MRI, MRA, Doppler studies
Treatment:
•Anticoagulation therapy – Immediate and long term
•Surgical intervention if necessary
•Drugs that limit calcium cascade
•Long term pharmacological therapy with ACE inhibitors for protection of endothelial
lining
•Rehabilitation
•Decrease controllable risk factors
ICP – CAUSE, ASSESSMENT, TREATMENT/MANAGEMENT
•The brain is enclosed by the rigid nonexpanding skull.
•Contents:
•_blood (10%),
•_brain tissue (80%),
•_cerebral spinal fluid (10%)
•Increase ICP Decomposition
Cause:
•Injury (internal or external)
•Disease factors
•Chemical
Assessment:
•Monitor LOC*****
•Arousal and wakefulness
•Content and cognition
Treatment:
•Identify and correct precipitating factor (poisoning, CVA, head trauma)
•Limit pt’s actions and ADLs that cause valsalver maneuvers (coughing, baring down)
•Internal ICP monitoring in ICU
Pain – types and treatments
n_CUTANEOUS PAIN
–sharp, burning
–origin in the skin or subcutaneous tissue
n_DEEP SOMATIC PAIN
–diffuse, throbbing
–origin in muscle, bone and radiating to surrounding tissue
n__VISCERAL _PAIN
–Diffuse, poorly defined
–origin from stretching, distention, or ischemia of body organ
nREFERRED_PAIN
–originate at a visceral site
–perceived as originating in part of the body wall that is innervated by neurons
entering the same segment of the nervous system
–Hypothesized that the same dorsal horn neurons are shared
–The sites of referred pain are developed embryologically during the same
developmental periods
n_PSYCHOGENIC_PAIN
–originating in the mind, not in the body however exhibiting physical symptoms
AUTONOMIC DYSREFLEXIA – SYMPTOMS, CAUSES, TREATMENTS
•An acute episode of exaggerated sympathetic responses
•Occur in persons with injury at T6 and above, CNS control of spinal reflexes is lost.
•Usually occurs 6 months after injury
Symptoms:
•Vasospasms – Pallor initially
•Mild to server hyptension. Gooseflesh associated with piloerector response
•Bradycardia produced by baroreflex-mediated vagal response
•Baroreflex-mediated vasodilatation with flushed moist skin
Cause:
Stimuli initiating the response
•Visceral distention: full bladder or bowel
•Pain receptors: ingrown toe nail, dressing change
•Visceral contractions: ejaculation, bladder spasms, uterine contractions
Treatment:
•Remove/Correct the initiating cause
•Monitor VS – Especially BP
•Place in upright position
•Remove peripheral support hose
•Promote venous pooling, decreasing BP
•Drugs to block the autonomic response may be needed
RESPIRATORY FUNCTION & DISORDERS:
STRUCTURES & FUNCTION:
- Conducting Airways: warms, filters, and humidifies the air
- Nasopharyngeal Airways: nose, mouth, oropharynx
- Laryngotracheal Airways: larynx connects the oropharynx with the trachea
- Tracheobronchial Tree: trachea, bronchi, and bronchioles – “branching tubes”
- Respiratory Bronchiole: the first bronchiole upon which alveoli appear
-Alveolar Sacs and Alveolus
REGULATION:
-Involuntary: controlled by the Medulla Oblongata in the Brain
-Drive to Breath – Carbon Dioxide and Hydrogen ions (blood acidity – pH)
-Sensory neurons in carotid arteries and aorta
-The more CO2 you hold the more acidic your body becomes
ASSESSING:
-Rate 12-20 breaths per minute
-More than 20 breaths per minute: tachypnea
-Less than 12 per minute: bradypnea
-Depth is hyperpnea and hypopnea
-Character: does it look they have to work to breath
-Lung Sounds
-O2 Saturation – greater than or equal 9
LUNG VOLUMES & PATTERNS:
- Inspiration: active process – you can choose when you want to inhale
- Expiration: passive process – you can’t choose when you exhale
*When you inhale: intrathoracic pressure it goes up; the diaphragm goes down; the pressure in
the space goes down
- Ventilation: two types:
1. Pulmonary: gas exchange between atmosphere and lungs
2. Alveolar: exchange of gases in the lungs
- Perfusion: supplying blood to the alveoli to facilitate gas exchange
1. Pulmonary artery (deoxygenated blood) to lungs to pulmonary vein
(oxygenated blood)
LUNG VOLUMES:
- Tidal Volume (TV): amount of gas you inhale and exhale with normal breath – about
500 mL – inhale and exhale of normal volume
- Inspired Reserve Volume (IRV): all of the air you can suck in
- Expiratory Reserve Volume (ERV): all the air you can force out
- Residual Volume (RV): volume of air never leaves
LUNG CAPACITIES:
- Total Lung Capacity (TLC): all 4 volumes measured when lung is completely inflated
- Vital Capacity (VC): maximum of expired; inspiratory and expiratory
- Functional Residual Capacity (FRC): expiratory and residual volume; all gases remain
in lung after a passive expiration
- Inspiratory Capacity (IC): amount of gas that inspired after a passive expiration; tidal
and inspiratory volume
PNEUMOTHORAX:
- Spontaneous Pneumothorax: is the sudden onset of a collapsed lung without any
apparent cause, such as a traumatic injury to the chest or a known lung disease
- Open Pneumothorax: occurs when air accumulates between the chest wall and the
lung as the result of an open chest wound or another physical defect
- Tension Pneumothorax: is a life-threatening condition that develops when air is
trapped in the pleural cavity under positive pressure, displacing mediastinal
structures and compromising cardiopulmonary function
ASTHMA:
- Signs and Symptoms:
1. Wheezing
2. Decrease breath sounds
3. Nonproductive cough
4. Increased respiratory rate
-Problem: bronchoconstriction – Fixed: a medication for bronchodilation
- Chronic Inflammatory Disorders of the Airways:
Early Phase:
1. IgE, histamine release
2. Mucus – increased goblet cell production
3. Bronchospasm
Late Phase:
1. Inflammatory Mediators
2. Epithelial Cell Injury
3. Edema
4. Accumulation of Mucus
Treatment:
1. Nebulized Treatments (bronchodilators) – help break down mucus to have the
patient cough it up
2. Oxygen – because they are lacking it
3. Steroids – help break down inflammation
4. Epinephrine – bronchodilator
5. 2-3 L water per day – to thin mucus/secretion
COPD: CHRONIC OBSTRUCTIVE PULMONARY DISEASE
- Includes:
1. Chronic bronchitis
2. Emphysema
3. Chronic Asthma (sometimes)
- Mechanisms of Airflow Obstruction:
1. Normal bronchial airway
2. Hypertrophy
3. Inflammation and hypersecretion of mucus
4. Loss of elastic fibers – smoking
- Airway Obstruction with COPD:
1. Effects of Smoking:
Alpha one anti-trypsin enzyme deficiency
Inflammation
Fibrosis
- Patient Teaching:
1. The best way to treat COPD are to catch it early and to stop smoking
- Signs & Symptoms:
1. Shortness of breath
2. Barrel chest (increased in anterior/posterior chest, diameter)
3. Alveolar wall destruction
4. Destruction of elastin (loss of elastic recoil)
5. Enlarged mucous glands
6. Over inflated lungs
- Respiratory Drive:
1. COPD patients retain CO2
2. Their drive to breathe is NOT high CO2
3. It is low O2
- Treatment:
1. Smoking cessation
2. Home O2
3. Bronchodilators
4. Steroids
5. Fluids
MINUTE VENTILATION: TIDAL VOLUME X THE NUMBER OF TIMES YOU BREATH PER MINUTE
NORMAL VENTILATION AND PERFUSION:
-Ventilation = 4L inspired air
-Perfusion = 5L circulating blood
-VQ ratio = 4:5 or 0.8
INADEQUATE PERFUSION – DEAD SPACE:
-Ventilation = 4L air
-Perfusion is Reduced or Absent – 3L blood
-VQ ratio 4:3 or 1.333
INADEQUATE VENTILATION – SHUNT:
-Ventilation is LOW = 2L air
-Perfusion is normal 5L blood
-VQ ratio 2:5 or 0.4
PARTIAL PRESSURE & DIFFUSION:
Partial Pressures of O2 & CO2
-A = alveolar pressure – goes down
-a = arterial pressure – relatively low
-V = venous pressure – relatively high
-PAO2 partial pressure of O2 in the alveoli
-PaO2 partial pressure of O2 in the arteries
-PvO2 partial pressure of O2 in the venous system
FACTORS INFLUENCING DIFFUSION OF GAS:
-Thickness of the membranes
-Amount of surface area
-Solubility of gas
-Pressure difference of gases
-Diffusion moves from high concentration to low concentration
-Concentration gradient is required for gas exchange
GAS TRANSPORT:
-Oxygen transport
-Carbon dioxide transport
-Oxyhemoglobin dissociation curve – how well it move across
VQ RATIO:
-VQ Ration: ration of ventilation to perfusion – expresses the effectiveness of gas
exchange
