Cardiac Flashcards
(40 cards)
Concentric vs eccentric hypertrophy
Con-seen with LVH and HTN from pressure overload
Eccentric-seen with volume overload
Diuretics can cause which electrolyte derangements?
Decreased K, Mg, NA.
Increased glucose, Urate, lipid, and possibly increased K
Probs with Calcium channel blockers:
Can cause heart block, myocardial depression, potentiation of NMB, peripheral edema and reflex tachycardia (nifedipine)
Pre-op assessment for HTN: Look for signs of CHF when you see HTN? What else to look for-labs, imaging, ECG?
Yes look for CHF signs.
BUN/Cr for rental involvement, Na/K for diuretic effects, ECG for LVH, CXR for cardiomegaly and pulmonary edema
Pre-medication in a pt with HTN:
BP neds?
Sedation and anxiolytics are often good
Acute control with beta blockers can be helpful
Where from baseline should BP be kept?
Within 20% unless it is markedly elevated
Anesthetic significance of HTN
CV, Renal, Neuro. Causes if HTN:
Hemodynamics profile-HTN-early va late and how it relates to CO and SVR
LVH, diastolic dysfunction, vasopressin sensitivity, increased risk of MI, CHF, Aortic dissection
Rental-overactivity of RASS system and nephropathy
Neuro-potential increase risk of stroke and right shift of auto regulation curve
Causes: essential, followed by renal, endocrine-hyperaldosteronidm, Cushing’s, costctstion, drug side effects (estrogen)
HTN early vs late-early increased CO with normal SVR. Later-increase in SVR without Co
Cancel the case at which BP? A line for everyone?
There is no absolute cutoff. Emergency-would proceed no matter what the BP. It depends on the cause of HTN, chronic ott, symptomatomogy, difficulty with it being controlled, co-existing disease and type of surgery to be performed.
Best induction technique for OT with HTN?
No absolute beat technique, but a good one would include avoiding precipitous drops in BP from a rapid induction, achieve a deep level of anesthesia prior to laryngoscopes and intubation, and avoid vasopressors
HTN with a full stomach?
HTN with full stomach-need to analyze which risk is greater-aspiration or BP lability on induction. Elective-wait, had to proceed and aspiration risk low-proceed with slow induction.
High aspiration risk-a line prior to induction, RSI with etomidate and sux
Difficult airway, full stomach, HTN
Airway first-needs to be spontaneously breathing:
Supplemental O2, sedation!!, a line, topicalize airway with aerosolized 2%lidocaine, topicalize nasal mucosa with lidocaine jelly and phenylephrine. Glossopharyngeal, superior laryngeal, trans trachea blocks
How to do a glossopharyngeal, superior laryngeal, and tramstracheal block:
Hug
Automatically use etomidate?
No. In the normal, euvokemic, or HTN patient, it is not as reliable in preventing HTN with laryngoscopy and intubation
Ketamine in HTN patients-is it contraindicated?
It may cause more tachycardia and HTN, but no contraindicated especially if it currently hypotension or hypovolemic. Catecholamine depletion would unmask the direct myocardial depressant effect of ketamine, but the patient would still be spontaneously breathing
After surgery, your hypertensive patient is HTN in PACU-what to do?
Make sure HTN is real
ABCs-hypoxia and hypercarbia can cause sympathetic stimulation
Limb leads:
Criteria of ischemia on EKG:
Oscillometry concept:
Limb-1,2,3
1 mm ST depression, or 2 mm ST elevation
Oscillometry-cuff inflates to Supra systolic pressures and deflated in increments. Arterial pulsations are measurable oscillations in pressure
How big should a BP cuff be?
Too small va too large
For every 1 cm the cuff is above the heart? Below?
Width of cuff should extend at least 1/2 of extremity’a length, and be 20-50% greater than the extremity’s diameter
Too small-overestimates. Too large-underestimates
Above-subtract 0.7
Below-add 0.7
Dampening coefficient:
What is overdamped?
What is underdamped?
How to stop these deviations?
Coefficient-tendencybfor fluid only the system to extinguish motion.
Over-flattened waveform-lower DBP. Kink, clot, loose connection, large air bubble.
Under-exaggerated waveform, overestimation of BP.
Stiff tubing, small mass if fluid (short length), fee stopcocks
Risks of a line:
Hematoma, thrombosis, infection (femoral), nerve injury
Central venous catheter-what is the point?
Draw CVP wAveform
Explain each
Monitor right heart filling pressures and waveforms
A-atrial contract in, c-ventricular systole (tricuspid calve bulges into atrium), v-venous return, x descent-downward displacement ofnventricle during systole. Y descent-atrial emptying with opening of tricuspid valve.
Cannon a wave-
Tricuspid stenosis, RVH, AV block, LV noncompliance.
Giant CV waves-
tricuspid regurgitation or right papillary muscle ischemia.
6 indications for CVP. Does pressure equal volume?
When is CVP unreliable to measure left sided filling volumes?
CVP is properly placed where-
- Monitoring CVP
- Fluid resuscitation
- Infusion of drugs and hyper alimentation
- Insertion of pacing leads
- Venous access in patients with poor peripheral veins
- Aspiration of air with Air emboli
Pressure doesn’t always equal volume because the 2 are related by compliance. Compliance= volume/pressure
Unreliable with pulmonary hypertension, not just because if pulmonary arterial hypertrophy, but also RV non compliance
Properly placed at junction of SVC and RA
No in left due to thoracic duct and higher apex of lung
PAC-directions and indications
Goes from RA-RV-PA-pulmonary arterial where it wedges
Indications-when it is important to monitor any or All of 4 variables:
1. Filling pressures-pulmonary edema, volume status (large fluid shifts), conditions such as tamponade and primary pulmonary HTN
2. CO-thermodikution
3. Calculated hemodynamics indices-SV, CI, SVR, PVR
4. MVO2
Volume status-things May elevate CVP without elevating PCWP (right sided heart stuff) Distinguishing cardiac (high PCWP) be non cardiac pulmonary edema
