Week 3 Clinical Medicine: Shock, PAD, Pediatric Cardiology Flashcards
What are the 3 determinants of Stroke Volume (SV)?
Preload, Myocardial Contractility, Afterload
What is Shock and what is it caused by?
- inadequate tissue perfusion to meet metabolic demand and tissue oxygenation
causes: inadequate supply or increased demand (or both!)
What is the difference between Compensated, Decompensated, and Irreversible Shock?
Comp: reflex compensatory mechanisms activated to maintain perfusion to vital organs
- blood shunts CENTRAL; HR/contractility INC
- Sympathetic tone, catecholamines, RAAS INC
Decomp: tissue hypoperfusion and circulatory/metabolic derangement
- hypotension and lactic acidosis
Irreversible: organ/tissue injury SEVERE, correction CANNOT fix (survival impossible)
What is the difference between:
Cardiogenic Shock
Hypovolemic Shock
Distributive Shock
Obstructive Shock
What are they caused by?
C: BAD PUMP
- cardiomyopathy, Arrhythmias, Mechanical (ex: valves)
H: dec. intravascular volume
- hemorrhage or dehydration (non-hemorrhagic)
D: dec. SVR
- drugs or sepsis
O: mechanical obstruction of circulatory system
- ex: tension pneumothorax, pulmonary embolism
What is Cardiogenic Shock and what are its 3 subtypes?
What physiological changes are associated with it? (CO/SVR/CVP)
- “pump failure” = HEART is the PROBLEM
- CO dec. and SVR/CVP inc.
Subtypes:
- Cardiomyopathies (MC; ischemic, infect., drugs)
- Rhythm Problems (bradycardia/tachycardia)
- Valvular/Congenital (stenosis/VSD/etc)
Heart Muscle Problems (Cardiomyopathies) MOST COMMON CAUSE
What is Hypovolemic Shock and what are its 2 subtypes?
What physiological changes are associated with it? (CO/SVR/CVP)
- loss or lack of INTRAVASCULAR VOLUME
- CO/CVP dec. and SVP inc.
Subtypes:
- Hemorrhagic (blood loss)
- Non-hemorrhagic (fluid loss)
- dehydration (vomit, diarrhea, dec. intake)
- 3rd spacing (cirrhosis)
- through the skin (BURNS)
What is Distributive Shock and what are its 2 subtypes?
What physiological changes are associated with it? (CO/SVR/CVP)
- vasodilation of vascular beds causes dec. Systemic Vascular Resistance (SVR)
- SVP/CVP dec. and CO inc. (Neuro? = ALL decreased)
Subtypes:
- Septic (septic shock)
- Non-septic (neuro, anaphylactic, toxin/meds)
What is Obstructive Shock?
What physiological changes are associated with it? (CO/SVR/CVP)
What are 3 examples of this type of shock?
- mechanical obstruction within the cardiopulmonary system causing restriction of blood flowing into/out of heart
- dec. CO, inc. SVR, variable CVP
ex: tension pneumothroax, pericardial tamponade, pulmonary embolism
What is the goal of Shock treatment and what are 4 things that should be given to pts. suffering from shock? (F/V/US/A)
Goal: initial/rapid restoration of tissue hypo-perfusion and identifying the underlying cause
Tx: IV fluids, vasopressors, US evaluation (RUSH protocol to determine type), and broad spectrum antibiotics if infection thought to be cause (SEPSIS)
What are considerations when treating children and the elderly patients for possible shock?
Kids: hypotension not seen till too late
- will present with tachycardia and NORMAL BP
- work FAST to correct underlying tachycardia
Elderly: usually on cardiac medication
- may not see tachycardia (masked by meds)
- WORK UP
What are the screening guidelines for patients with Carotid Artery Stenosis?
- asymptomatic pts. should NOT be screened
- screening for pts with known atherosclerotic disease OR pts with carotid BRUITS using Carotid Duplex Ultrasound (tells us if stenosis is there, but not grade)
What are the screening procedures for patients suspected of Abdominal Aortic Aneurysm?
What pathology is seen on screening?
- abdominal ultrasonography as initial screen
- useful for 65-75 yo men (NOT women) who have a history of smoking
- see curvilinear calcifications outlining portions of aneurysm wall in 75% of pts.
What are the two treatment options for pts. with Aortic Aneurysm?
- Emergency Repair: endovascular repair has some improvement over open surgery
- bleeding hopefully confined to retroperitoneum
- open surgery: graft above and below aneurysm
- Elective Repair: indicated for aneurysms > 5.5 cm or those with rapid expansion (> 0.5 cm in 6 months)
What imaging is used to visualize an Abdominal Aortic Aneurysm?
CT scans or CT scans /contrast (can see vasculature)
- can also use US which is less risky (no contrast)
- can estimate size and see presence of aneurysm
Lower Extremity Arterial Disease
What is the most commonly affected artery due to atherosclerosis?
What testing can be done on these patients?
MC: superficial femoral artery
- common femoral and popliteal arteries also involved
- result in short-distance claudication (CALF PAIN)
Testing: Ankle-Brachial Indices
- no recommended for ASYMPTOMATIC pts.
- has excellent accuracy compared to angiography
Lower Extremity Arterial Disease
What findings on ABI are diagnostic for PAD?
What imaging can be done on pts. with PAD?
Diagnostic: ABI < 0.9
- < 0.4 = chronic limb-threatening ischemia
- toe-brachial index < 0.7 diag. (DM/CKD pts)
- vessels above are calcified; ABI can be misleading
Imaging: duplex US, CT angiography, MR angiography
- show anatomic location of lesions
- done ONLY if revascularization is planned
Lower Extremity Arterial Disease
What are the two treatment options available to pts. with PAD?
- Medical/Exercise Therapy
- dec. risk factors, high-dose statin, exercise
- Surgical intervention - claudication incapacitating
- bypass/endovascular surgery
- thromboendarterectomy
Lower Extremity Arterial Disease
What are the 4 drugs used to medical treat this disease?
Antiplatelet drugs: aspirin/clopidogrel
- prevent clotting in region of the plaques
PDE3 inhibitor: Cilostazol (selective antiplatelet/vasodil.)
- shows inc. exercise tolerance in severe claudication
Pentoxifylline: NOT RECOMMENDED
What are major risk factors of PAD, especially below and above age 50?
age < 50 w/Diabetes and an additional risk factor
- smoking, hypertension, homocysteinemia, lipidemia
age 50-69 yrs with smoking AND diabetes
- abnormal LE pulses, leg symptoms w/exertion or rest, known atherosclerotic disease
What is the screening process for pts. with suspected PAD?
- if patient has risk factors for PAD or symptoms of claudication, screen with ABI
- if ABI is negative but are still suspicious of PAD, perform an Exercise Stress Test and then recheck ABI
What does the leg of a patient with Chronic Venous Insufficiency (CVI) look like?
- discolored skin from stasis dermatitis; yellow color from lipodermosclerosis
- large ulcerations seen at or above medial ankle (venous ulcers)
- darker brown areas from hemosiderin deposition as fluid leaks into tissue (heme pigment)
NOT CELLULITIS
What are the clinical findings of patients with Chronic Venous Insufficiency?
- progressive pitting edema is presenting symptom
- usually itching, dull discomfort with standing, pain if ulcer present (above ankle)
- varicosities may be present
What imaging is done on a patient with Chronic Venous Insufficiency and what is the classical scenario of presentation?
Image: duplex US to determine superficial reflux and degree of deep reflux/obstruction
CS: elderly female with CVI, given compression stockings and rest w/leg elevation = no help
- now do duplex US to look for venous reflux
What are the two treatment options available to a patient suffering from Chronic Venous Insufficiency?
- fitted, graduated compression stockings from foot to just below knee during day/evening
- avoid long times of sitting/standing, elevate leg
- Vein Treatment
- superficial vein reflux (varicose) surgery can dec. venous ulcer rate
- do NOT remove varicose if femoral/popliteal vein obstruction
What congenital heart defects are associated with Trisomy 21?
What sounds does an Atrial Septal Defect make?
Midline Septal Defects (ASD and VSD/AVSD/PDA)
- ASD causes as FIXED SPLIT S2 on auscultation
What congenital heart defect is associated with a Holosystolic murmur?
Are diastolic murmurs ever normal?
VSD
- obscures normal S1 and S2 sounds
- diastolic murmurs are NEVER NORMAL (usually low pitched with a “rumbling” characteristic)
What is the only Diastolic Murmur that does NOT warrant referral to cardiology?
Venous Hum
- caused by flow of venous blood from the head and neck into the thorax (can be heard continuously while child is sitting)
What pathologic murmur increases in intensity as the pt stands or during Valsalva maneuver?
What does it sound like and where?
HYPERTROPHIC CARDIOMYOPATHY (idiopathic hypertropic subaortic stenosis)
- harsh crescendo-decrescendo systolic murmur best heard at apex and LSB
- causes a left ventricular outflow tract obstruction
What is a Still’s Murmur?
- innocent murmur heard best at the apex and LLSB using the BELL of the stethoscope
- dec. intensity with inspiration, sitting up, standing
What are the 5 cyanotic lesions of the heart?
How are ductal dependent lesions screened for in children?
Truncus Arteriosus (1 big trunk)
Transposition of Great Vessels (2 interchanged vessels)
Tricuspid Atresia (3)
Tetralogy of Fallot (4)
Total Anomalous Pulmonary Venous Return (5)
- do O2 saturation checks both pre-ductally and post-ductally
What is the screening procedure for checking of CHD in children?
- check children > 24 hrs old or shortly before discharge if < 24 hrs old
- if < 90% O2 in right hand/foot = failed screen
- if 90-95% in right hand/foot OR > 3% difference between –> screen in 1 hr, then screen 1 more hour if needed
- if failed 3 screenings = failed screen
- if > 95% in right hand/foot AND < 3% difference between right hand/foot = PASSED SCREEN
Pediatric Hypertension
Which children should be checked and how does using too small/too large of cuff change the readings?
- check pediatric BP in all children > 3 yrs old
Cuff too small = artificial ELEVATED BP
Cuff too large = artificial LOWERED BP
