Coronary Artery Bypass
By: Brittney Mathis RN, BSN
Saphenous vein -> Right Coronary Artery and Circumflex
Internal Mammary Artery-> Left Anterior Descending Coronary Artery
Patency over 90% after 10 years
If more are needed, upper extremity veins can be used but patency is less than 40% after 5 years
Veins Used for Bypass
Explain the lines that will be in place after surgery-ET tube, ART, Cortis, chest tubes, Foley
Explain use of IS following surgery and its importance. Go ahead and practice
Educate on proper body mechanics and sternal precautions that will be used for 6-8 weeks. Go ahead and practice.
Chest and both legs are to be shaved completely The night before and morning of surgery, patient
is to take a chlorohexadine bath and swish/swallow
Preoperative
Connect patient to proper monitors STAT CBC, PT, PTT, BMP, MG, ABG, and glucose STAT EKG, CXR Connect chest tubes to suction and MONITOR
CHEST TUBES: q15mins for 1 hour and then hourly. Call physician if output >150 mL first hour or >100 mL/hr thereafter ◦ If it is greater, draw STAT PT/PTT, CBC, and Fibrinogen
and call surgeon Vitals signs every 15 minutes, including CVP, PA,
CO/CI, and SVO2. Record an SVR every 4 hours or so, you may need to look up how to calculate it.
Immediate Postoperative
See Handout
Calibrating Vigilence
Patient CVP needs to 7-12 mm Hg for hearts.
CI >2.2 If these are low=patient needs volume This allows a proper amount of volume to
keep the new grafts open and patent Standing orders for volume: 1Liter NS, 1
Liter Albumin (start with this), and sometimes 1 Liter of Hesban (don’t give if actively bleeding)
Can give one unit of PRBC if Hgb<8
Volume
MAP is usually to be kept between 65-75 A MAP greater than 75 puts the patient at risk
for rupturing a bypass suture and increases bleeding (chest tube output) from the suture line.
There will always be either Cardene, Nitroglycerin gtt, or sometimes Nipride ordered
If the patient systolic blood pressure is less than 90 and not responding to volume, call physician.
Blood Pressure Control
Potassium is to be kept >4.0 mmol/L Magnesium is to be kept >1.8 Calcium is to be kept >8.5
If at any time a CV surgeon rounds and these are not correctly, I can guarantee him to get angry.
Electrolyte Replacement
Tamponade is the filling of the pericardium with fluid, pus, or blood.
This can happen if bypass was not stitched well and the chest tubes cannot drain fast enough or the chest tubes are not
patent Signs: increased CVP above PA pressures, decreased BP, increasedHR, muffled heart sounds, pulsusparadoxus, and decreased CO/CI
Sign of Tamponade
There is a Cardiac Weaning Protocol for Fast track. Best Practice: extubated in 6 hrs, OOB in 2 hours Criteria-no acute ischemia, hemodynamically
stable, absence of new arrhythmia, blood loss <2 mL/kg.hr, awakening from anesthesia (following commands and lifting head off pillow), core temp >97.0 F
1. Pt placed on CPAP2. ABG in 30 mins3. NIF and VC 4. Call anesthesiologist for orders
Extubation
These are to be followed for 6-8 weeks to allow proper healing of the sternum.
Do not lift more than 5-8 pounds. (Roughly a half gallon of milk)
No pushing or pulling with your arms. Do not reach behind your back or reach both arms out to
the side. Do not reach both arms overhead. Brace sternum with pillow while getting up, sitting down,
coughing, and sneezing.
Failure to follow these directions can result in sternal wires breaking and a surgical procedure to fix them will be needed.
Sternal Precautions
Incentive Spirometer is to be done a minimum of 10 times every hour
Coughing and deep breathing (use sternal precautions)
Proper analgesics (promote deep breathing) Early ambulation
All of these decrease the risk for postoperative pulmonary complications that include: pneumonia and atelectasis.
Post Extubation Respiratory Care
Pharmacology
Propofol
Antifibrinolytic Agent-minimizes bleeding and decrease need for transfusion
Dose: Monitor: incision sites for bleeding and
chest tubes for clots
Aminocaproic acid (Amicar)
Mechanism of Action: calcium channel blocker than inhibits calcium ions from entering cardiac and vascular smooth muscle cells. causes arteries to dilate and blood pressure to decrease
Use: decrease BP, Increase CO, decrease SVR
Dosage: premixed bag of 40 mg in 200 mL. recommended starting dose at 5 mg/hr for max dose of 15mg/hr
Can be mixed in pharmacy for higher concentration on CRRT patients
nicardipine hydrochloride (Cardene)
(Cardene I.V., 2013)
Dosage: 5 - 200 mcg/min Must be mixed in glass bottle &
administered is special tubing
Nitroglycerin
Mechanism of Action: Relaxes vascular smooth muscle to reduce afterload & preload
Use: decrease blood pressure
Dosage: 0.5 - 8 mcg/kg/min
Precautions: Protect from light and monitor serum Thiocyanate levels. Nipride metabolizes to cyanide. Cyanide toxicity can develop within 1 hr with infusions >10 mcg/kg/min
Sodium Nitroprusside (Nipride)
Phosphodiesterase inhibitor; positive inotrope with little chronotropic effect; direct vasodilator (decreases both preload & afterload) activity
Uses: heart failure Dosage: Load: 50 mcg/kg IVP over 10
minutes. Then 0.375-0.75 mcg/kg/min IV infusion
Milrinone (Primacor)
("Medscape Reference," 2013)
Levophed
Dopamine
Phenylephrine (Neosynphrine)
Mechanism of Action: Strong alpha effects resulting in increased peripheral vascular resistance and blood pressure; decreases cardiac output and renal perfusion
Use: Severe hypotension or shock
Dosage:20mg/250ml D5W at 100-180 mcg increments IV bolus, THEN 40-60 mcg/min continuous IV infusion
Side effects: pulmonary edema, V-tach, metabolic acidosis
Mechanism of Action: inotropic agent whose primary activity results from stimulation of the b-receptors of the heart
Use: Increase contractility and CO in heart failure
Dosage:2.5 -10 mcg/kg/min
Warnings: may precipitate or exacerbate ventricular ectopic activity
Weaning: 1mL/hr, weaning too quickly can cause arrhythmias
Dobutamine HCl (Dobutrex)
Albumin
Hesban
Beta Blocker
Aspirin
Milrinone. (2013). Retrieved June 11, 2013, from http://reference.medscape.com/drug/milrinone-342433#0
Cardene I.V. (2013). http://www.cardeneiv.com/c1_cardeneiv_ov.shtml
References
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