Cardiovascular system Flashcards Preview

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Flashcards in Cardiovascular system Deck (124)
1

heart tissues

Pericardium:
-fibrous protective sac enclosing the heart

Epicardium:
-inner ayer of pericardium

Myocardium:
-heart muscle, major portion of the heart

Endocardium:
-smooth lining of the inner surface and cavities of the heart

2

heart chambers

RA: receives blood from vena cava

Tricuspid valve

RV: receives blood from RA and pumps blood via pulmonary artery to lungs for O2
"low pressure pulmonary pump"

LA: receives oxygenated blood from lungs and 4 pulmonary veins

Bicuspid valve

LV: receives blood from LA and pumps via aorta t/o systemic circulation
"high pressure systemic pump"

3

Heart valves

Atrioventricular valces: prevent back flow during ventricular systole
-R tricuspid
-L bicuspid

Semilunar valves: prevent backflow from aorta and pulmonary A into ventricle during diastole
-Pulmonary valve: prevents R backflow
-Aortic valve: prevents L backflow

4

systole=

ventricular contraction

end systolic ventricle volume ~50 mL

5

diastole=

ventricular relaxation and filling

end diastolic ventricle volume ~ 120 mL

6

atrial contraction

"atrial kick"

occurs during the last 1/3 of diastole and completes ventricular filling

comprising last 20-30% of end diastolic volume

7

coronary circulation

arteries: arise directly from aorta near aortic valve; blood circulates to myocardium during diastole
-R coronary A
-L coronary A
----L anterior descending
----Circumflex

Veins: parallel arterial system; coronary sinus receives venous blood from the heart and empties into the RA

8

Conduction:

specialized conduction tissue: allows rapid transmissionof electrical impulses throughout the myocardium (NSR)

Normal sinus rhythm:
-Origin in SA node- impulse spreads t/o both atria, which contract together
-impulse stimulates AV node, is transmitted down bundle of His Purkinje fibers
-impulse spreads t/o the ventricles which contract together (atrial kick)

9

SA node

-located at junction of vena cava and RA
-**main pacemaker of the heart; initiates impulse rate of 60-100 bpm
-has sympathetic and parasympathetic innervation affecting both HR and strength of contraction

10

AV node

-located at junction of RA and RV
-has sympathetic and parasympathetic innervation
-merges with bundle of His
-intrinsic firing rate of 40-60 bpm

11

Purkinje tissue

-R and L bundle braces of the AV node are located on either side of intraventricular septum
-terminate in Purkinje fibers, specialized conducting tissue spread t/o ventricles
-intrinsic firing rate of 20-40 bpm

12

Stroke volume=

the amount of blood ejected with each myocardial contraction

normal range= 55-100 mL/beat

Influenced by:
1- L ventricular end diastolic volume: the amount of blood left in the ventricle at the end of diastole (AKA preload). The greater the preload, the greater the quantity of blood pumped-- Frank starling law
2-contractility: ability of the ventricle to contract
3- Afterload: the force the LV must generate during systole to overcome aortic pressure to open the aortic valve

13

Cardiac output

the amount of blood discharged from the L or R ventricle per minute

average adult at rest= 4-5 L/min

determined by HR x SV

14

Left ventricular end diastolic pressure

pressure in the LV during diastole

normal range 5-12mm Hg

15

Ejection fraction

percentage of blood emptied from the ventricle during systole

clinically useful measure of LV function

EF= SV/LVEDV

SV= blood ejected with contraction
LVEDV= blood left in ventricle at end of diastole (preload)

normal EF averages >55%
-lower EF= more impaired LV

16

atrial filling pressure

the difference between the venous and atrial pressures

R atrial filling pressure is decreased during strong ventricular contraction and atrial filling is enhanced

R atrial filling pressure is affected by changes in intrathoracic pressure; decreases during inspiration and increases during coughing or forced expiration

venous return increases when blood volume expands and decreases during hypovolemic shock

17

diastolic filling time decreases with:

increased HR and with heart disease

18

myocardial oxygen demand (MVO2)

represents the energy cost to the myocardium

clinically measured by the product of HR and SBP
AKA Rate pressure product (RPP)

MCO2 increases with activity and with HR and/or BP

19

R coronary artery supplies:

RA
most of RV
and in most individuals the inferior wall of LV, AV node and bundle of His

Supplies SA node 60% of the time

20

L coronary artery supplies:

most of the LV

2 divisions:

1- L anterior descending: supplies LV and the inter ventricular septum
-in most individuals the inferior areas of the apex
-may also give off branches to RV

2- Circumflex: supplies blood to the lateral and inferior walls of the LV and portions of the LA
-supplies SA node 40% of the time

21

arteries

transport oxygenated blood from areas of high pressure to lower pressures in the body tissues

only exceptions:
-umbilican vein (in utero)
-pulmonary veins

arterial circulation is maintained by heart pump

influenced by elasticity and extensibility of vessel walls, and by peripheral resistance, amount of blood in the body

22

arterioles

terminal braces of arteries that attach to capillaries

primary site of vascular resistance

23

capillaries

include small blood vessels that connect the ends of arteries (arterioles) with the beginning of veins (venues)

form an anastomosing network

function for exchange of nutrients and fluids between blood and tissues

capillary walls are thin and permeable

24

veins

transport dark, unoxygenated blood from tissues back to the heart

larger capacity, thinner walls than arteries, greater number

1 way valves to prevent back flow

venous system includes both superficial and deep veins (deep veins accompany arteries while superficial ones don't)

venous circulation is influenced by muscle contraction, gravity, respiration (increased return with inspiration), compliancy of R heart

25

lymphatic system

includes:
-lymphatics (superficial, intermediate, and deep)
-lymph fluid
-lymph tissues and organs (lymph nodes, tonsils, spleen, thymus, thoracic duct)

drains lymph from bodily tissues and returns it to venous circulation


major lymph nodes:
-submaxillary
-cervical
-axillary
-mesenteric
-iliac
-inguinal
-popliteal
-cubital

26

what order does lymph travel ?

lymph travels to lymphatic capillaries to lymphatic vessels to ducts to L subclavian vein

27

lymphatic contraction occurs by?

lymphatic contraction occurs by:
-parasympathetic, sympathetic and sensory nerve stimulation
-contraction of adjacent muscles
-abdominal and thoracic cavity pressure changes during normal breathing
-mechanical stimulation of dermal tissues
-volume changes within each lymphatic vessel

28

how does lymphatic system contribute to immune system function?


-lymph nodes collect cellular debris and bacteria
-remove excess fluid, blood waste and protein molecules
-produce antibodies

29

neurohumeral influences of cardiovascular system:

1- parasympathetic stimulation (cholinergic)

2- sympathetic stimulation (adrenergic)

3-additional control mechanisms
-baroreceptors (pressoreceptors) - control HR
-chemoreceptors -sensitive to changes in blood chemicals: O2, CO2, lactic acid
-body temperature
-ion concentration

4-peripheral resistance

30

parasympathetic stimulation

cholinergic

control located in medulla oblongata, cardioinhibitory center

via vagus nerve (CN X), cardiac plexus; innervates all myocardium; releases acetylcholine

slows rate and force of myocardial contraction; decreases myocardial metabolism

causes coronary artery vasoconstriction

31

sympathetic stimulation

adrenergic

control located in medulla oblongata, cardioacceleratory center

via cord segments T1-4, upper thoracic to superior cervical chain ganglia
-innervates all but ventricular myocardium
-releases epinephrine and norepinephrine

causes an increase in the rate and force of myocardial contraction and myocardial metabolism

causes coronary artery vasodilation

the skin and peripheral vasculature receive only postganglionic sympathetic innervation
-causes vasoconstriction of cutaneous arteries; -sympathetic inhibition must occur for vasodilation

drugs that increase sympathetic functioning= sympathomimetics

drugs that decrease sympathetic functioning= sympatholytics

32

baroreceptors

(pressoreceptors)

main mechanisms controlling HR

located in walls of aortic arch and carotid sinus; via vasomotor center

Circulatory reflex: respond to changes in BP
-increased BP results in parasympathetic stimulation, decreased rate and force of cardiac contraction; sympathetic inhibition, decreased peripheral resistance
-decreased BP results in sympathetic stimulation, increased HR and BP and vasoconstriction of peripheral blood vessels
-increased RA pressure causes reflex acceleration of HR

33

chemoreceptors

located in carotid body

sensitive to changes in blood chemicals: O2, CO2, lactic acid

increased CO2 or decreased O2, or decreased pH (elevated lactic acid) results in an increase in HR

increased O2 levels result in a decreased HR

34

neurohumoral influences: ion concentrations

hyper/hypo kalemia

hypo/hyper calcemia

hypo/hyper magnesemia

35

Hyperkalemia

increased concentration of potassium ions:
-decreases the rate and force of contraction
-produces ECG changes -- widened PR interval and QRS, tall T wave

36

Hypokalemia

decreased concentration of potassium ions:

-produces ECG changes -- flattened T waves, prolonged PR and QT intervals
-arrhythmias may progress to ventricular fibrillation

37

Hypercalcemia

increased calcium concentration

increases heart actions

38

Hypocalcemia

decreased calcium concentration

depresses heart actions

39

Hypermagnesemia

increased magnesium is a calcium blocker which can lead to arrhythmias or cardiac arrest

40

Hypomagnesemia

decreased magnesium causes ventricular arrhythmias, coronary artery vasospasm and sudden death

41

peripheral resistance

increased peripheral resistance increases arterial blood volume and pressure

decreased peripheral resistance decreases arterial blood volume and pressure

influenced by arterial blood volume: viscocity of blood and diameter or arterioles and capillaries

42

patient interview

Presenting symptoms:
-chest pain, palpitations, SOB
-fatigue
-dizziness, syncope
-edema

Positive risk factors

Negative risk factors
-high serum
-HDL >60 mg/dL

PMH:
-other diagnoses, surgeries
-meds

social history:

quality of life issues
-functional mobility
-ADLs, sleep

observation and inspection of skin color for possible signs of decreased CO and low O2 saturation
-cyanosis
-pallor
-diaphoresis

43

cyanosis

bluish color of the skin, nail beds, lips and tongue

related to decreased CO

44

pallor

washed out, absence of pink, rosy color

associated with decreased peripheral blood flow, PAD

45

diaphoresis

excess sweating and cool, clammy skin

46

non-modifiable risk factors for cardiovascular disease

Age:
-men >45
-women >55

Family history:
-cardiac event in 1st degree male relative pre-menopausal women

47

Modifiable risk factors for cardiovascular disease (goals to reduce risk)

Cholesterol:
-total: 40 mg/dL (men); >50 (women)
-Triglycerides:

48

physical exam for cardiovascular system

pulse

heart sounds

heart rhythm

blood pressure

respiration

oxygen saturation

pain

49

grading scale for peripheral pulses

0= absent pulse, not palpable

1+= pulse diminished, barely perceptible

2+= easily palpable, normal

3+= full pulse, increased strength

4+= bounding pulse

50

HR norms

adult and teens: 60-100 bpm
-40-60 in aerobically trained

children: 60-140 bpm

newborn: 90-164 bpm

51

tachycardia

HR >100 bpm

compensatory tachycardia can be seen with volume loss (surgery, dehydration)

positional tachycardia syndrome:
-sustained HR increase >30 bpm per minute within 10 minutes of standing (>40 bpm in teens)

52

bradycardia

HR

53

pulse abnormalities

irregular pulse: variations in force and frequency; may be due to arrhythmias, myocarditis

weak, thready pulse: may be due to low SV, cardiogenic shock

bounding, full pulse: may be due to shortened ventricular systole and decreased peripheral pressure; aortic insufficiency

54

auscultation landmarks

aortic valve:
2nd R intercostal space at sternal border

pulmonic valve:
2nd L intercostal space at sternal border

tricuspid valve:
4th L intercostal space at sternal border

bicuspid valve:
5th L intercostal space at midclavicular area

55

Normal heart sounds

S1 "lub"
-normal closure of mitral and tricuspid valves
-marks beginning of systole
-decreased in 1st degree heart block

S2 "dub"
-normal closure of aortic and pulmonary valves
-marks end of systole
-decreased in aortic stenosis

56

murmurs

extra sounds

systolic: falls between S1 and S2
-may indicate valvular disease (mitral valve prolapse) or may be normal

diastolic: falls between S2 and S1
-usually indicates valvular disease

grades of heart murmurs:
1- softest audible murmur
6- audible with stethoscope off the chest

thrill: an abnormal tremor accompanying a vascular or cardiac murmur
-felt on palpation

57

bruit

an adventitious sound or murmur (blowing sound) or arterial or venous origin

common in carotid or femoral arteries

indicative of atherosclerosis

58

gallop rhythm

an abnormal heart rhythm with 3 sounds in each cycle; resembles the gallop of a horse

S3:
-associated with ventricular filling
-occurs soon after S2
-in older individuals may indicate CHF (LV)

S4:
-associated with ventricular filling and atrial contraction
-occurs just before S1
indicative of pathology (CAD, MI, aortic stenosis, or chronic HTN)

59

P wave

atrial depolarization

60

PR interval

time required for impulse to travel from atria through conduction system to Purkinje fibers

normal 0.12-0.20 seconds

61

QRS wave

ventricular depolarization

62

ST segment

beginning of ventricular repolarization

ST segment changes:
-with impaired coronary perfusion (ischemia or injury), the ST segment becomes depressed
-depression can be upsweeping, horizontal or downsloping
-ST depression or elevation >1mm measured at the J point in 2 consecutive leads is considered abnormal

63

T wave

ventricular repolarization

64

QT interval

time for electrical systole

65

ventricular arrhythmias

originate from an ectopic focus in the ventricles (outside normal conduction system)

significant in adversely affecting CO

1-premature ventricular contractions (PVCs)

2- Ventricular tachycardia

3- Ventricular fibrillation

66

Premature ventricular contractions

a premature beat arising from the ventricle

occurs occasionally in the majority of the normal population

on ECG:
-no P wave
-bizarre and wide premature QRS
-followed by a long compensatory pause

serious PVCs: >6/min, paired or in sequential runs, multifocal, very early PVC

67

Ventricular tachycardia

a run of 3 or more consistent PVCs

very rapid rate (150-200 bpm)

may occur paroxysmally (abrupt onset)

usually the result of an ischemic ventricle

ECG:
-wide, bizarre QRS waves
-no P wave

Seriously compromised CO

Non-sustained ventricular tachycardia (NSVT): 3 or more consecutive beats in duration, terminating spontaneously in 30 seconds in duration and/or requiring termination due to hemodynamic compromise in

68

Ventricular fibrillation

a pulseless, emergency situation requiring emergency medical services; cardiopulmonary resuscitation (CPR), defibrillation, meds.

characterized by chaotic activity of ventricle originating from multiple foci; unable to determine rate

ECG:
-bizarre, erratic activity without QRS complex

no effective CO

clinical death within 4-6 min

69

Atrial arrhythmias

(supraventricular)
rapid and repetitive firing of one or more ectopic foci in the atria (outside the sinus node)

on ECG: P waves are abnormal (variable in shape) or not identifiable (Afib)

rhythm may be irregular: chronic or occurring paroxysmally

Rate:
-rapid with atrial tachycardia (140-250 bpm)
-atrial flutter (250-350 bpm)
-atrial fibrillation (>300 bpm)

CO is usually maintained if rate is controlled; may precipitate ventricular failure in an abnormal heart

70

Atrioventricular blocks

abnormal delays or failure to conduct through normal conducting system

1st, 2nd or 3rd (complete) degree AV blocks; bundle branch blocks

if ventricular rate is slowed, CO decreased

3rd degree, complete heart block is life threatening; requires meds (atropine), surgical implantation of pacemaker

71

Potassium level influence on ECG

hyperkalemia: decreases rate and force of contraction
-widens QRS
-flattens P wave
-T wave peaks

Hypokalemia:
-flattens T wave (or inverts)
-produces U wave

72

Calcium level influence on ECG

Hypercalcemia: increases heart actions
-widens QRS
-shortens QT interval

Hypocalcemia:
-prolongs QT interval

73

Hypothermia influence on ECG

elevates ST segment
slows rhythm

decreased body temp causes HR to decrease

74

Digitalis influence on ECG

depresses ST segment
flattens T wave (or inverts)
QT shortens

75

Quinidine influence on ECG

antiarrhythmia

QT lengthens
T wave flattens (or inverts)
QRS lengthens

76

beta blockers influence on ECG

(propanolol, inderal)

decreases HR, blunts HR response to exercise

77

nitrates influence on ECG

nitroglycerin

increases HR

78

holter monitoring

continuous ambulatory ECG monitoring via tape recording of cardiac rhythm for up to 24 hours
-used to evaluate cardiac rhythm, transient symptoms, pacemaker function, effect of meds

allows correlation of symptoms with activities

79

Normal BP

Adult:
-SBP

80

orthostatic hypotension

drop in BP that accompanies change from supine to standing position

initial BP and HR with patient in supine, at rest for >5 min

repeat measures at immediate standing and again at 3 minutes

orthostaic= SBP drops >20, DBP >10

common symptoms: lightheadedness, dizzy, LOB and leg weakness

81

mean arterial pressure (MAP)

the arterial pressure within the large arteries over time; dependent upon mean blood flow and arterial compliance

MAP= (SBP + DBPx2) / 3

important clinical measure in critical care

normal MAP 70-110 mmHg

82

respiratory rate

normal adult= 12-20 bpm
normal child= 20-30 bpm
normal newborn= 30-40 bpm

tachypnea= RR>22 bpm

bradypnea = RR

83

dyspnea

=SOB

dyspnea on exertion (DOE)

borg dyspnea scale:
0= nothing
10=maximal

84

orthopnea

inability breathe when in a reclining or supine position

85

paroxysmal nocturnal dyspnea

sudden inability to breathe occurring during sleep

86

Blood pressure levels

Normal/optimal
180 / >110

87

adventitious lung sounds

crackles (rales): rattling, bubbling sounds; may be due to decorations in the lungs

wheezes (rhonchi): whistling sounds

88

Anginal scale

1+ = light, barely noticeable

2+ = moderate, bothersome

3+ = severe, very uncomfortable

4+ = most severe pain ever experienced

89

pulse oximetry

an electronic device that measures the degree of saturation of hemoglobin with oxygen (SaO2)

normal 95-100% oxygen

provides an estimate of PaO2 (partial pressure of oxygen) based on oxyhemoglobin desaturation curve

90

hypoxemia

abnormally low amount of oxygen in the blood (SaO2

91

hypoxia

low oxygen level in the tissues

92

anoxia

complete lack of oxygen

93

ischemic cardiac pain

(angina or myocardial infarction)

diffuse, retrosternal pain; or a sensation of tightness, ashiness, in the chest

associated with dyspnea, sweating, indigestion, dizziness, syncope, anxiety

94

referred cardiac pain

cardiac pain can refer to shoulders, back, arms, neck or jaw

pain referred to the back can occur from dissecting AAA

95

examining the peripheral vascular system

Condition of extremities
-diaphoresis: associated with decreased CO
-arterial pulses: decreased/absent pulses associated with PAD; examine bilaterally distal>proximal
-skin color: cyanosis, pallor, rubor
-skin temperature
-skin changes
-pain: intermittent claudication
-edema:

tests for peripheral venous and arterial circulation

examine lymphatic system

96

rubor

dependent redness with PAD

97

skin changes

clubbing:
-curvature of the fingernails with soft tissue enlargement at base of nail
-associated with chronic oxygen deficiency, chronic pulmonary disease or heart failure

trophic changes
-pale, shiny, dry skin, with loss of hair is associated with PAD

fibrosis
-tissues are tick, firm and unyielding
-Stemmer's sign: dorsal skin folds of the toes and fingers are resistant to lifting
-indicative of fibrotic changes and lymphedema

abnormal pigmentation, ulceration, dermatitis, gangrene: all associated with PAD

temperature: decrease in superficial skin temp is associated with poor arterial perfusion

98

Intermittent claudication

pain, cramping and LE fatigue occurring during exercise and relieved by rest
-associated with PAD

typically in calf; may also be in thigh, hips or buttocks

patient may experience pain at rest with severe decrease in arterial blood supply; typically in forefoot, worse at night

99

peripheral causes of edema:

chronic venous insufficiency and lymphedema

bilateral edema is associated with CHF

100

grading scale for pitting edema

1+ mild, barely perceptible indentation
30 seconds or more
>1 in pitting

101

tests for peripheral venous circulation

examine venous circulation before arterial (venous insufficiency can invalidate some arterial tests)

1- Percussion test- greater saphenous vein

2-Trendelenburg test (retrograde filling test) - communicating veins and saphenous system

3- Venous filing time

4- doppler US

5- air plethysmography (APG)

102

tests of peripheral arterial circulation

1- ankle brachial index (ABI)

2- rubor of dependency

3- intermittent claudication
-have patient walk on level grade, stop with pain
-note time, subjective rating of pain
-examine for coldness, numbness or pallor, loss of hair over anterior tib
-leg cramps may also result from diuretic use with hypokalemia

103

ABI

the ratio of LE pressure divided by UE pressure

pt in supine and at rest for 5 min

BP at brachial artery and at posterior tibial or doornails media arteries

ABI assists in risk stratification for cardiovascular disease

>1.40 indicates non-compliant arteries

1 - 1.4 = normal

0.91 -0.99 = borderline

104

rubor of dependency

examine color changes in skin during elevation of foot followed by dependency (seated, hanging position)

with insufficiency, pallor develops in elevated position; reactive hyperemia (rubber of dependency) develops in dependent position

changes that take >30 seconds are also indicative of arterial insuffienciency

105

examining the lymphatic system

palpate superficial lymph nodes: cervical, axillary, epitrochlear, superficial inguinal

examine for edema

examine skin
-changes in texture, fibrotic tissue changes
-presence of papules, leakage, wounds

changes in function

paresthesias might be present

lymphangiography and lymphoscintigraphy using radioactive agents (X-ray of lymph vessels)

106

subjective rating of pain with intermittent claudication

I: min discomfort or pain

II: moderate discomfort/pain; patient's attention can be diverted

III: intense pain; patient's attention can't be diverted

IV: excruciating and unbearable pain

107

chest xray

will reveal abnormalities of lung fluids, overall cardiac shape and size (cardiomegaly), aneurysm

108

myocardial perfusion imaging

used to diagnose and evaluate ischemic heart disease, myocardial infarction

Thallium-radioisotope injected into blood

used to identify myocardial blood flow, areas of stress induced ischemia (exercise test), old infarcts

positron emission tomography (PET)- radioactive marker

109

echocardiogram

non-invasive

US to assess internal structures: size of chambers, wall thickness, EF, movement of valves, septum, abnormal wall movement

110

cardiac catheterization

passage of a tiny tube from brachial or femoral artery through aorta into blood vessels with introduction of a contrast medium into coronary arteries and subsequent x-ray

provides info about anatomy of heart and great vessels, ventricular and valve function, abnormal wall movements

allows determination of EF

111

central line (swan ganz catheter)

catheter inserted through vessels into R side of heart

measures central venous pressure, pulmonary artery pressure, pulmonary capillary wedge pressures

112

cardiac MRI

creates 3D images of the heart to investigate coronary arteries, aorta, pericardium and myocardium

113

arterial blood gases

SpO2:

PaO2:

PaCO2:

pH:

114

SpO2

normal: 98-100%

115

PaO2

90-100 mmHg
partial pressure of oxygen

116

PaCO2

35-45 mmHg

increased in COPD, hypoventilation

decreased in hyperventilation, pregnancy, PE and anxiety

117

pH

7.35 - 7.45

7.45 = alkalosis
-respiratory alkalosis: hyperventilation, sepsis, liver disease, fever
-metabolic alkalosis: vomiting, potassium depletion, diuretics, volume depletion

118

hemostasis (clotting/bleeding times)

prothrombin time (PT): 11-15 seconds

partial thromboplastin time (PTT): 25-40 seconds

international normalized ratio (INR): ratio of one's PT to reference range: 0.9-1.1
-patients with DVT, PE100 mg/L associated with inflammation and infection

119

White blood cells

4300-10,800 cells/mm3
indicative of status of immune system

increased in infection: bacterial, viral; inflammation, hematologic malignancy, leukemia, lymphoma, drugs (corticosteroids)

decreased in aplastic anemia, B12 or folate deficiency

with immunosuppression: increased risk of infection

PT considerations:
-consider metabolic demands in presence of fever and use mask when WBCs

120

Red blood cell

"erythrocyte" - transports O2 and CO2 to and from tissues

male: 4.6-6.2
female 4.2-5.9

increased in polycythemia

decreased in anemia

121

Erytherocyte sedimentation rate

ESR

the speed at which the RBCs settle after an anticoagulant has been added to a blood sample
-the rate increases with infection or inflammation (RA, pelvic inflammatory disease)
-osteomyelitis- used to monitor effects of treatment

male:

122

hematocrit (Hct)

% of RBC in whole blood

males: 45-52%
females: 37-48%
*age dependent

increased in erythrocytosis, dehydration, shock

decreased in severe anemias, acute hemorrhage

PT considerations: can cause decreased exercise tolerance, increased fatigue and tachycardia

123

hemoglobin (Hgb)

male: 13-18 g/dL
female: 12-16 g/dL
age dependent

increased in polycythemia, dehydration, shock

decreased ni anemias, prolonged hemorrhage, RBC destruction (cancer, sickle cell)

PT considerations: can cause decreased exercise tolerance, increased fatigue and tachycardia

124

platelet count

150,00 - 450,000 cells/mm3

increased in chronic leukemia, hemoconcentration

decreased in thrombocytopenia, acute leukemia, aplastic anemia, cancer chemotherapy

PT considerations:
-increased risk of bleeding with low levels so monitor for hematuria, petechiae, and other signs of active bleeding