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

Video of Bypass

Intraoperative Care

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