Vascular and Pericardial Dx Flashcards
PMI
Perioperative Myocardial Infarction
When does myocardial ischemia occur?
O2 demand > O2 Supply
Which leads do we watch for ischemia?
V2 and V5
ST changes in STEMI
ST elevation possible T wave inversion
ST chnages in NSTEMI
ST depression or T wave inversion
Cardiac Risk for Non-Cardiac Surgeries: High Risk
TAMP
- Thoracotomy
- AAA
- Major Abdominal Procedure
- Peripheral Vascular Procedure
Cardiac Risk for Non-Cardiac Surgeries: Ischemia Heart DX
CHHUP
- Current Angina
- Hx of MI
- Hx of positive exercise test
- Use of Nitrates
- Presence of Q waves
Q wave: a small negative wave immediately before the large QRS complex
Cardiac Risk for Non-Cardiac Surgeries: CHF
HHH-PC
- Hx of CHF
- Hx of Pulmonary Edema
- Hx of paroxysmal noctural dyspnea
- Physcial with rales or S3 gallop
- Chest Xray shopwing pulmonaly vascular redistribution
Cardiac Risk for Non-Cardiac Surgeries: Cerebrovascular Dx
2
- Hx of CVA
- Hx of TIA
Cardiac Risk for Non-Cardiac Surgeries: Renal Function
Pre-op creatine > 2mg/dL
Cardiac Risk for Non-Cardiac Surgeries: DM
Insulin dependance
Why do patinets with DM have silent MI’s?
Nerve damage prevents them from feeling pain from MI
PMI management
- Prevent myocardial ischemia
- Avoid hyperventilation
- HR and BP within 20% of baseline
- Avoid sympathetic responses
PMI Intra-Op Events: Decreased O2 supply
OH-DATCHA
- Oxyhemoglobin shift: Left
- Hypotension
- Decreased coronary blood flow
- Arterial Hypoxemia
- Tachycardia
- Coronary Artery Spasm
- Hypocapnia
- Anemia
PMI Intra-Op Events: Increased O2 demands
SIIITH
- Sympathetic stimulation
- Increased Inotropy
- Increased Preload
- Increased Afterload
- Tachycardia
- Hypertension
PMI IntraOp treatment
1mm change in ST segment
- Nitro to reduce afterload
- Esmolol to reduce HR
- Inotropes to increase BP
PMI: Avoid in PostOp
SPS-HHH
- Shivering
- Pain
- Sepsis
- Hypoxemia
- Hypercarbia
- Hemorrhage
AAA’s are associated with what?
- Marfans
- Ehler-Danlos
- Bicuspid Aoritc Valve
- Family Hx
AAA’s not operated on until what size?
Larger than 5cm
Aortic Dissections are associated with what?
PTW-HABIT
- Pregnancy
- Tetrology of Fallot (TOF)
- Weight Lifting
- HTN
- Atherosclerosis
- Bicuspid Aortic Valve
- IABP/CABG/Aortic Surgery
- Trauma (from ligamentum arteriosum)
AAA Rupture Triad
- Severe Back Pain
- Pulsatile Abdominal Mass
- Hypotension
How are AAA patients stable until surgery?
The abdominal blood tamponades the rupture, once incision is made massive blood loss will happen
Aortic dissection classifications
2 kinds
- DeBakey
- Standford
DeBakey Type I
involves ascending and descending aorta (= Stanford A)
DeBakey Type II
involves ascending aorta only (= Stanford A)
Debakey Type III
involves descending aorta only, commencing after the origin of the left subclavian artery (= Stanford B)
Stanford Type A
type A involves any part of the aorta proximal to the origin of the left subclavian artery (A affects ascending aorta)
Stanford Type B
type B arises distal to the left subclavian artery origin
Medical Management of Ascending Aorta
Surgical Intervention
Medical Management of Aortic Arch
Surgical intervention
Medical Management of Aortic Arch involving the Innominate
AKA Brachiocephalic artery
- Bypass required
- Profound hypertension
- ± Circulatory Arrest
Medical Management of Descending Aorta
Surgical intervention only if about to rupture or growing too fast. Otherwise just medicically managed
What can aortic cross clamping do to the spine?
Anterior Spinal Artery Syndrome
How does Anterior Spinal Artery Syndrome manifest?
- Flaccid Paralysis
- Motor Dysfunction
* Lower Extremities
* Bowel
* Bladder - Acute back pain at the level of clamping/injury
- Autonomic dysfunction
How do we reduce the risk of Anterior Spinal Artery Syndrome?
- Cross clamp less than 30 mins
- Possible bypass if longer than 30 mins to increase blood flow
What happens to SVR distal and proximal to the clamp on the aorta?
Distal: SVR decrease
Proximal: SVR increase
Change in HR after aortic clamp?
None
What is the global venous response to te aortic clamping?
Vasoconstriction
What pressures increase after aortic clamping?
- CVP
- PAP
- PAWP
We need to measure pressures above and below clamp, how do we do that?
two art lines or NIBP cuffs
What MAP do we need to see above and below the clamp?
Above: 100mmHg
Below: 50mmHg
What three things have a habit of not getting perfused after clamping?
- Bowel
- Kidneys
- Splanchnic organs
Evoked Potentials and Aortic cross clamping
Catch 22
Motor: Can’t use, pt paralyzed
Sensory: only monitor dorsal aspect, we need ventral measurements
So what do we do?
- We can only insure we use proper perfusion pressures
- Lumbar Puncture drain (<10cm H2O of CSF)
- Iced Epidural Injection
Aortic Unclamping -vs- Clamping
- Un-clamp
- Peripheral blood pooling
- Central hypovolemia
- Decreased venous return
- Hypotension
Hypoxia mediated vasodilaiton and metabolite washout will ensue
Aortic Unclamping -vs- Clamping
- Clamping
- Vasoconstriction
- Increased venous return
- Increased lung and intracrainia blood volume
- Hypertension
Slow or fast release of the clamp is advised?
Slow
What does Mannitol do for the kidneys?
- Increase renal blood flow
- Increase GFR
Chilled LR, mannitol, and methylprednisilone is what?
Renal artery injection
Do we put a lower bair hugger on these patients?
No they will get a burn, body can not regulate heat during clamping
Endovascular aortic repair: Where is it more difficult?
Thoracic at the arch
Endovascular aortic repair: Management and precautions
- Spinal cord ischemia still possible
- Monitor BP with art line
- Monitor urine output
- Possible lumbar puncture
- Be ready to open
- maintain volume and BP
Know Circle of Wilis anatomy
- Ant, Middle, Post arteries
- Internal Carotid
- Vertebral arteries form Basilar Artery
Two types of strokes?
- Ischemic
- Hemorrhagic
Carotid Stenosis: Diagnosis
- Auscultation
- Angiography
- CT
- MRI
- Doppler
What are we listening for with the bell of the stethescope on the caroid?
Carotid bruit
“brewie”: sound made by stenotic vessel
When is surgery indicated for a stenotic carotid?
70-99% blockage, then pt gets a Carotid Endarterectomy
CEA
Carotid endarterectomy
CEA patients also have a high chance of what other diesases?
- CAD
- HTN
CEA: Regional Blocks
- This gives us a real time assesment of stroke as pt is awake and responsive
- We do a cervical plexus block and sedation
- Rarely used
CEA: General Anesthesia
We need to maintaine
* HR
* BP
* Pain
* Stress
CEA: Why do we get wild swings in hemodynamics?
Carotis sinus body: chemoreceptors and baroreceptors
manipulations give off signals to alter BP
CEA: Hemodynamic swing management
- Vasodilators
- Phyenylephrine / ephedrine
- Surgeon can inject local into the carotid body to help smooth out patient
CEA: perfusion / collateral flow concerns
- may or may not shunt to give adequate perfusion
- we need to monitor blood flow if we suspect cerebral ischemia
CEA: How do we monitor for cerebral ischemia?
- EEG
- SEP
- Doppler
- Cerebral Oximetry
- Stump Pressure
CEA: What is stump pressure?
non-compliant tubing attahced to a cannula is inserted into the cephelad aspect of the clamped carotid in order to determine if aquetuate collateral flow is present
CEA: What is cerebral oximitry?
measures tissue oxygen saturation
In the cerebral cortex what are the hemoglobin distrobution percentages?
- Venous: 70%
- Arterial: 30%
CEA: Post OP Complications
Cardiac
- HTN or Hypotension due to sinus body manipulations
- MI
CEA: Post OP Complications
Airway
- Tissue Edema
- Hematoma in neck
CEA: Post OP Complications
Neurologic
- Stroke
- thrombosis formation
- Hypoglossal dysfunction (motor tongue)
- RLN dysfunction (one sided vocal chord paralysis, hoarsness)
- Superior laryngeal dusfunciton (phonation chnages)
Which cranial nerve is the Hypoglossal?
12 (XII)
What is the pericardial sac
fibrous sac that produces fluid to help lubricate the movement of the heart
Anatomy
* Fibrous
* Serous
* Visceral
* Parietal
How much fluid is usually in the paericardial sac?
10-50mL
Small effusion streches what in the fibrous layer?
elastin
Large effusion streches what in the fibrous layer?
collagen
Drainage of pericardial sac, what lymnph nodes
BTM
Bronchial
Trachial
Mediastinal
Pericarditis
Most common pericardial disorder
- Friction rub
- Recurrent
- Mimincs MI but does not improve with Nitro
- Longer duration with slower onset
Pericardial effusion common causes
MIC-DRST
excess fluid in the pericardial sac
- MI
- Infection
- Cancer
- Drugs
- Radiaiton
- Systemic disease
- Trauma
MIC are the big three
Cardiac Tamponade
Fluid in the pericardial sac that causes severe cardiac compression
How do we diagnose tamponade
- Chest X ray
- CT
- TTE/TEE
Signs and symptoms of Cardiac Tamponade
AP-HIDE
- Activation of sympathetic system
- Pulsus Paradoxus
- Hypotension
- Increased ICP
- Decreased voltage on EKG
- Equalization of cardiac filling pressures
What adjacent structures can this tamponade compress?
- Esophagus
- Trachea
- Lungs
What is Kassmaul’s sign
Jugular vein distentsion on inspiration
What is Beck’s Triad
- Hypotension
- Jugular vein distention / increased pressure
- Muffled heart sounds
What is pulsus paradoxus
ventricular interdependence seen on EKG
decrease of >10mmHg in systolic pressure during spontaneous respiration
Cardiac Tamponade: EKG
- Lower QRS volatge (smaller QRS complex)
- Can see alternans
Cardiac Tamponade: Echo
- Small <10mm
- Medium 10-20mm
*Large >20mm - Chamber compression
- Swinging motion
- Collapse on inspiration
What two treats are available for cardiac tamponade
- pericardiocentesis
- pericardial window
What induction drug do we use for tamponade?
Ketamine
1-2.5mg/kg
Tamponade mangement
Preload dependant
Maintain CO
Maintain Inotopy
Maintain Chronotropy
Maintain SV
Tamponade: avoid what
- Myocardial depression
- Hypovolemia
- Hypervolemia
- Arterial Vasodilation
- Bradycardia
- PPV
Watch out for what two things after post decompression cardiac tamponade?
Hypertension induced
* Aortic dissection
* Aortic Aneurysm