Responses to Pathological Situations Flashcards
(37 cards)
systemic hypoxemia is
Subnormal partial pressure of O2 in the arterial blood
Causes of hypoxemia
1) high altitude
2) asphyxiation
3) lung pathology (chronic emphysema, pulmonary edema)
4) right-to-left shunts cong. heart defects
Humans respond to arterial hypoxemia w/ 3 primary compensatory changes
1) resting hyperventilation
2) increased cardiac output
3) peripheral vasodilation
Clinical shock (definition)
potentially fatal, pathophysiological disorder characterized by acute failure of the cardiovascular system to perfuse the tissues of the body adequately.
Clinical signs of Shock
1) pale, cold, sweaty skin; venoconstricted
2) weak & rapid pulse
3) reduced pulse pressure
4) rapid & shallow breathing
5) reduced urine output
6) reduced mental awareness/confusion, muscle weakness, collapse
4 Categories of clinical shock
1) hypovolemic shock
2) cardiogenic shock
3) septic shock
4) anaphylactic shock
Causes of hypovolemic shock
fall in circulating blood or plasma volume.
- hemorrhage
- diarrhea
- vomiting
- dehydration
- extensive burns
- crush injuries
- pancreatitis
Signs of hypovolemic shock
- increases systemic vascular resistance
- poor skin turgor
- thirst
- oliguria
- low systemic & pulmonary preloads
- rapid heart rate
Cardiogenic shock
acute impairment of cardiac function by myocardial infarction, myocarditis, or arrhythmia
signs of cardiogenic shock
- ekg changes
- cool,clammy skin
- hypotension
- decrease in urinary output
- need for O2 supplementation
Septic shock
cardiovascular toxins, such as endotoxin from bacterial infection.
signs & symptoms of septic shock
- warm and cold phase
- altered mental status
- high fever
- tachycardia
- increased respiration
- elevated WBC
- hypotension
- decreased urinary output
anaphylactic shock
intense allergic reaction to antigens to which the patient has become sensitized, such as foodstuffs, insect bites, antibiotics.
Fainting (syncope)
sudden, transient loss of consciousness. Abrupt fall in arterial blood pressure.
Fainting can be caused by:
1) hemodynamic stress such as hypovolemia
2) postural hypotension
3) paroxysmal coughing
4) exercise w/ aortic valve stenosis
5) emotional stress such as fear or horror
clinical hypertension
most common chronic disease; progressive, raised arterial blood pressure.
essential hypertension
hypertension without an obvious predisposing organic cause
benign essential hypertension
almost symptomless, found during routine check-ups, predisposing factors: dietary salt intake, obesity, excessive alcohol consumption, stress, lack of exercise
malignant hypertension
rapid increase in blood pressure leading to cardiac failure, peripheral edema, renal damage w/ proteinuria, hypertensive encephalopathy, retinopathy
secondary hypertension
has an identifiable pathological cause and is uncommon
Treatment for hypertension
1) ACE inhibitors/angiotensin receptor blockers
2) Calcium-channel blockers
3) Diuretics
4) Beta-adrenoceptor blockers
Congestive heart failure
chronic inability of the heart to maintain adequate tissue perfusion at a normal filling pressure.
Causes of Left Heart Failure
1) diffuse coronary artery disease
2) reduce myocardial mass due to infarct
3) excessive work (afterload) due to clinical hypertension
4) cardiomyopathy
5) cardiac failure in elderly, idiopathic myopathy arising from myocytes
signs/symptoms of Left Heart Failure
1) shortness of breath
2) orthopnea (dyspnea on lying down)
3) paroxysmal nocturnal dyspnea
4) pulmonary congestion and edema (crackles)
5) exercise intolerance