Open heart surgery is any surgery where the chest is opened and surgery is done
on the heart muscle, valves, arteries, or other parts of the heart (such as the
aorta). The term "open" means that the chest is "cut" open.
The definition of open heart surgery has become confusing because new
procedures are being done on the heart through smaller cuts. Some new
procedures are being done with the heart still beating(off pump).
Conditions commonly treated with open heart surgery include
• Heart valve surgery
• Atrial septal defect
• Cardiac transplant
• Coarctation of the aorta
• Congenital heart defect corrective surgery
• Heart bypass surgery (coronary artery bypass graft - CABG)
• Mitral valve surgery
• Tetralogy of Fallot
• Ventricular septal defect (VSD)
• Congenital defect repair,
• Coronary artery bypass graft (CABG), commonly called heart bypass
surgery. CABG provides a new route around diseased coronary arteries with
healthy vessels taken from other places of body. This is the most common
heart surgery in adults.
• Heart transplant to remove a severely damaged heart and replace it with a
• Heart valve repair or replacement when a heart valve does not function
properly. Heart valves control the flow of blood into and out of the heart.
• Implantation of medical devices to help control heartbeat or support
proper heart function
• Transmyocardial laser revascularization when coronary artery bypass is
not an option.
• The surgeon uses lasers to make channels directly in the heart muscle to
supply it with blood.
• Maze procedure, which is the creation of scar tissue to block irregular
electrical signals through the heart.
• The Maze procedure is used to treat atrial fibrillation or an irregular
heartbeat that is not amenable to medications or less invasive methods.
Types of open heart surgery
• The types of open heart surgery procedures include:
• On-pump surgery uses a heart-lung machine (cardiopulmonary bypass). This
machine temporarily takes over the heart’s job of pumping oxygen-rich blood to
the organs and tissues. This is the traditional type of open heart surgery. It allows
surgeon to operate on a heart that is not beating and has no blood travelling
• Beating heart or off-pump surgery does not use a heart-lung machine and surgeon
operates on an actively beating heart. However, surgeon will slow heart rate with
medication or a device. This type of open heart surgery is limited to a few specific
• Robot-assisted surgery allows surgeon to use a special computer to control robotic
arms that perform the surgery. The surgeon sees a three-dimensional view of the
surgery on the computer. This type of surgery is very precise. However, it also is
limited to a few specific procedures.
• Before cardiac surgery, the patient’s history should be taken n carefully
examination for factors that might predispose to complications, such as the
Cardiac Risk Index Criteria :
• History of myocardial infarction
• History of current angina
• Use of sublingual nitroglycerine
• Positive exercise test results Q waves on electrocardiogram
• Patients who have undergone percutaneous transluminal coronary angioplasty
coronary artery bypass graft surgery and who have chest pain presumed to be
of ischemic origin
• History of transient ischemic attack
• History of cerebrovascular accident
• Diabetes mellitus requiring insulin therapy
• Chronic renal insufficiency, defined as a baseline creatinine level of at least 2.0
Routine preoperative investigations
• Full blood count (abnormalities corrected)
• Clotting screen
• Creatinine and electrolytes
• Liver function tests
• Screening for methicillin-resistant Staphylococcus aureus
• Chest radiography
• Echocardiography or ventriculography (to assess LV function)
• Coronary angiography (to define the extent and location of CAD)
In addition to the standard anesthetic monitoring (ECG, pulse oximetry,
nasopharyngeal temperature, urine output, gas analysis),
Specific monitoring requirements for cardiac surgery include the following:
• Invasive blood pressure
• Central venous access
• Transesophageal echocardiography (TEE)
• An arterial line is a fine plastic tube, called a cannula, which is inserted into the
patients’ artery. The cannula is attached to a transducer and infusion line (drip).
There are two main purposes of an arterial line.
• Firstly when patients are very sick an arterial line is inserted to provide constant
monitoring and recording of the patient’s blood pressure.
• Secondly some patients require frequent blood tests and the arterial line provides
easy access to a patient’s blood.
• Thus reducing the number of times a blood vessel will be accessed with a needle
and reducing patient pain.
• Arterial blood gases (ABG) are important blood tests that assist in monitoring the
patient’s oxygen status. An ABG can only be taken from an artery.
Pulmonary Artery Catheter
• Invented in 1970 by Swan, Ganz
and colleagues for hemodynamic
assessment of patients with acute
• Standard PAC is 7.0, 7.5 or 8.0
French in circumference and 110
cm in length divided in 10 cm
Pulmonary Artery Catheter
• PAC has 4-5 lumens:
– Temperature thermistor located
proximal to balloon to measure
pulmonary artery blood temperature
– Proximal port located 30 cm from tip
for CVP monitoring, fluid and drug
– Distal port at catheter tip for PAP
– +/- Variable infusion port (VIP) for fluid
and drug administration
– Balloon at catheter tip
• Diagnostic assessment of shock states (cardiogenic, distributive, hypovolemic) and assessment
of response to treatment
Using cardiac output, stroke volume, systemic vascular resistance
• LV preload and LV performance, pulmonary vasomotor tone, intravascular volume status,
especially in the context of acute lung injury
• Right heart pressures
Using right atrial pressure, pulmonary artery pressure
• Intracardiac shunt
• Assess volume status
• Assess RV or LV failure
• Assess Pulmonary Hypertension
• Assess Valvular disease
• Cardiac Surgery
• IJV, subclavian, femoral also possible
• The aims of premedication are to minimize myocardial oxygen demands by reducing heart
rate and systemic arterial pressure and to improve myocardial blood flow with vasodilators.
Drugs that should be continued up to the time of surgery are as follows:
• Beta-blockers, calcium channel blockers, and nitrates
• Agents given are as follows:
• Temazepam immediately preoperatively
• Midazolam, a small IV dose in the operating room before arterial line insertion
• Each patient should be cross-matched with blood , fresh frozen plasma, and platelets .
Tranexamic acid (bolus 1 g before surgical incision followed by an infusion of 400 mg/hr
during surgery) may be considered to reduce postoperative mediastinal bleeding and blood
product (ie, red blood cell and fresh frozen plasma) use
• Monitoring equipment is attached and peripheral venous access achieved but before
the arterial line is inserted, the midazolam dose is administered. Before placement of
the arterial line, it should be ensured that a radial artery graft will not be used for
• Cardiac surgery makes use 2 forms of neuraxial blockade:
• Intrathecal opioid infusion
• Thoracic epidural anesthesia (generally a low-dose local anesthetic/opioid infusion)
• During induction and tracheal intubation, it is important to maintain a steady heart rate
and blood pressure.
• Patients should be preoxygenated.
• Induction of anesthesia is accomplished by using high doses of opioid (usually fentanyl
20-40 microgrm/kg or remifentanil) to minimize the dose of propofol,
etomidate0.3mg/kg, or thiopental 2.5-4.5mg/kg and thereby maximize cardiovascular
• Although etomidate usually minimal myocardial depression then propofol and
A number of agents may be used for muscle relaxation
Intubating dose of muscle relaxant:
• Succinylcholine 1mg/kg duration 5-10min.
• Pancuronium 0.08-0.12mg/kg duration 60-120min.
• Vecuronium 0.15-0.2mg/kg/ duration 45-90min.
• Rocuronium 0.6-1mg/kg duration 35-75min.
• Atracurium0.5-0.6mg/kg duration 30-45min
• However, they each have their own associated complications, as follows:
Succinylcholine is depolariser and lead to cardiac arrhythmias and bradycardia.
Increases myocardial oxygen demand by increasing HR, CO and BP.
Vagal effect produse by anaesthesia and surgical stimuli that concealed by
vagolytic effect of Pancuronium
• Vecuronium may cause bradycardia in association with opioids
• Rocuronium can cause tachycardia, and also decrease PAP.
• Atracurium (which is not considered suitable for operations of long duration) can
cause hypotension secondary to histamine release.
• Votatile anaesthetic agent
• Halothane decrease BP due to decrease SV and CO.
• It sensitises the myocradium to catecholamines n lead to development of arrhythmias.
• It causes dose dependent decrease in BP, by decreasing SVR
• It dose not destablise the heart rhythm even in presence of Adr.
• It also sensitises the myocradium to catecholamines
• It produse coronary vasodilatation lead to decrease coronary perfusion pressure.
• It produse fluoride ions which may toxic to kidney.
• Most common use in cardiac surgery due to favorable haemodynamic effect and
• It decrease SVR arterial BP and CO in dose dependent fashion with tendency to lower HR.
• The trachea should be intubated orally because nasal intubation may
cause significant bleeding once heparin is administered.
• A double-lumen endotracheal tube is required if CABG is being performed
via a left thoracotomy.•
• Central venous access should be obtained. It is not uncommon for the
patient to become hypotensive. To ensure that there is sufficient diastolic
pressure to maintain coronary perfusion, hypotension should be treated
with IV fluids or with an alpha agonist if LV function is depressed.
• Typically, maintenance of anesthesia is accomplished with an opioid
infusion (fentanyl, alfentanil, sufentanil, or remifentanil) combined with
either a propofol infusion (total IV anesthesia) or a volatile agent. Volatile
agents are generally carried in an air-oxygen mixture because the use of
nitrous oxide as a carrier is controversial. Isoflurane may have a
myocardial protective effect and therefore is especially useful in off-pump
Cardiopulmonary bypass machines
• The CPB machine has five basic components:
Venous reservoir, an oxygenator, a heat exchanger, a main pump, and an arterial filter.
• Venous reservoir
• The reservoir of the CPB machine receives blood from the patient via one or two
venous cannulas in the right atrium or the superior and inferior vena cava.
• Blood flows to the reservoir by gravity drainage. Because venous pressure is
• Blood is drained by gravity from the bottom of the venous reservoir into the
oxygenator, which contains a blood–gas interface that allows blood to equilibrate
with the gas mixture (primarily oxygen).
• Heat Exchanger
• Blood from the oxygenator enters the heat exchanger.
• The blood is then either cooled or warmed, depending on the temperature of the
water flowing through the exchanger (4–42°C); heat transfer occurs by conduction.
• Main Pump
• Modern CPB machines use either an electrically driven double-arm roller (positive
displacement) or a centrifugal pump to propel blood through the CPB circuit.
• Arterial Filter
• Particulate matter (eg, thrombi, fat globules, calcium, tissue debris) enters the CPB
circuit with alarming regularity.
• Although filters are often used at other locations, a final, in-line, arterial filter is
mandatory to prevent systemic embolism. .
• The filter is also designed to trap air,
Management of CPB machine
Priming - Hemodilution
Hypothermia - Aortic Clamping - Myocardial protection → Total CPB
Rewarming - Weaning from CPB
Priming - Hemodilution
filling the CPB circuit with blood or blood substitutes
result in hemodilution
• Isotonic Saline, Ringer’s solution, Lactated Ringer’s, Dextrose solutions
• Albumin 5~25%, , 5% plasma protein fraction, 6% hydroxyethyl starch, FFP
Blood components: pRBC, (autologus) Whole blood
• Mannitol, Heparin, Corticosteroids, Calcium
• Reduce transfusion and transfusion complications
• Lower blood viscosity, improve organ perfusion
• Decrease the mechanical destruction of blood cells at extracoporeal circuit
• Lower immune and Inflammatory response
• Coagulability ↓, reduce emboli formation
• Typically a loading dose of 200-300 u/kg of heparin is given and then heparin
activity is monitored by measuring ACT ,( binds with antithrombin III )
• Check to see if ACT is 450-480 sec. then administer supplemental heparin based on
subsequent ACT levels :
• Method: give directly into a central vein or right atrium, verification ACT in 3~5
• Target: Activated Coagulation Time (ACT) > 480 secs, don’t begain CPB if ACT is less
This protection occour because of a decrease metabolic rate and oxygen
The metabolic rate is determined by enzymatic activity which is depend on
This also decrease rate of degradative reactions, increase tolerance to
necessary for cardiac arrest
It also inhibits intracellular Ca2+ accumulation
nasopharyngeal or tympanic membrane probes reflect brain temperature
rectal probe or skeletal muscle needle sensor
Mild to moderate (24~28℃) systemic hypothermia is preferred for its
control cooling speed, evenly .
After adequate cooling, reduce perfusion speed and cross-clamp the ascending aorta
establish total CPB
The term myocardial protection refer to strategies and mathadologies used either to
attenuate or to prevent post ischemic myocardial disfunction that occours during and
after heart surgery.
Reduction of metabolic activity by hypothermia.
Therapeutic arrest of contractile appearatus and all electrical activity of myocite by
administating cardioplagic solution(eg. Depolarizing of membrane potential by high
potassium blood cardioplagia
Maintenance of normal cellular integrity and function during CPB depends on reducing
energy expenditure and preserving the availability of high-energy phosphate.
This is accomplished by systemic and topical cardiac hypothermia(Ice flushing, about
4℃) and the use of potassium cardiplegia
Avoid ventricular fibrillation and distention(LV venting)
Following initiation of CPB, induction of hypothermia, and aortic clamping,
The coronary circulation is infused intermittently with cold cardioplegia
extracellular K+↑ → transmembrane potential↓ → inactivate Na+ channel
→ cardiac arrest
Repeated about every 30 minutes
Intra CBP Monitoring
• Flow rate
• Blood pressure(MAP,CVP, PAP)
• SaO2, SvO2
• Blood gas
• Urine output
MAP: in mild to moderate hypothermia
• normal adult: > 50mmHg
• adult with HTN, CAD, DM, and old age: > 60mmHg
• infants: > 30mmHg
• maintain adequate blood volume, α-receptor agonist, ephedrine,
• maintain between 0.6~1.0 mmol/L, to avoid rapid accumulation of
intracellular calcium during reperfusion
• excessive cardioplegia, severe hemolysis, and acidosis lead to
• Management: Ca2+ supplement, bicarbonate, ultrafiltration, glucose &
Off CPB: (Weaning)
Target: Core Temperature > 37℃, Shell Temperature > 34℃
Rewarming Evenly!!: use vasodilator
Hypothermia induce ventricullar fibrillation
• Spontaneous myocardial activity
• ABG, electrolyte , Hct, to be optimized
• Ventilation started
• Trendlenburg position to remove intra cardiac air.
• Beating heart examined by
• Poor contraction- give inotrops
• Decrease SVR give vasopressore
• As pt.meets criteria for sepration from CPB
• Perfusionist gradually clamps venous tubing so decrease blood flow to
reservoir and increase venouse return to heart.
• Arterial pump head is slowed cause gradually filling the heart.
• Appropriate preload is established
• Pulsatile arterial wave achieved and CBP terminated.
Morbidity Associated With open heart Surgery
• Neurological impairment after open heart surgery may be attributable to hypoxia,
emboli, hemorrhage, and/or metabolic abnormalities.
• Postoperative neurological deficits have been divided into 2 types:
• Type 1, associated with major, focal neurological deficits, stupor, or coma;
• Type 2, in which deterioration in intellectual function is evident.
• Deep sternal wound infection occurs in 1% to 4% of patients after bypass surgery
and carries a mortality of ≈25%.
• Predictors of this complication include obesity, reoperation, use of both internal
mammary arteries at surgery, duration and complexity of surgery, and diabetes.
• Postoperative renal dysfunction occurs in as many as 8% of patients.
• Among patients who develop postoperative renal dysfunction (defined as a postoperative
serum creatinine level >2.0 mg/dL ), 18% require dialysis.
• Overall mortality among patients who develop postoperative renal dysfunction is 19% and
approaches two thirds among patients requiring dialysis.
• Predictors of renal dysfunction include advanced age, a history of moderate or severe
congestive heart failure, prior bypass surgery, type 1 diabetes, and prior renal disease.
• Patients with advanced preoperative renal dysfunction who undergo CABG surgery have an
extraordinarily high rate of requiring postoperative dialysis.
• Among patients with a preoperative creatinine level >2.5 mg/dL, 40% to 50% require
• Predictors of poor long-term survival after bypass surgery include advanced age,
poor LVEF, diabetes, number of diseased vessels, and female sex.
• In some studies, additional predictors include angina , hypertension, prior MI, renal
dysfunction, and clinical congestive heart failure.
• Predictors of the recurrence of angina, late MI, or any cardiac event also include
obesity , as well as those factors identified above. Of these events, the return of
angina is the most common and is primarily related to late vein-graft
atherosclerosis and occlusion.
• Venous thromboembolism (VTE), which includes deep venous thrombosis (DVT)
and pulmonary embolism (PE), are quite common causes of morbidity and
mortality that are largely preventable in the postoperative patient.
• Surgical patients in particular have significantly increased risks for VTE due to
advanced age, multiple medical comorbidities, and prolonged procedure times, in
addition to the hypercoagulable state of surgery and immobility. Thus, clinicians
must consider VTE risk and risk-reduction strategies in all patients undergoing
• Patient-related risk factors for VTE include age older than 40 years, malignancy,
immobilization, varicose veins, severe cardiopulmonary disease (prior MI,
congestive heart failure, chronic obstructive pulmonary disease), prior stroke,
paralysis or spinal cord injury, prior VTE events, hyperviscosity syndromes
(polycythemia vera or malignancy related), and major vascular injury.
• prevent VTE events are categorized into nonpharmacologic and pharmacologic
• Nonpharmacologic methods include:
• early ambulation,
• graduated compression stockings,
• intermittent pneumatic compression devices.
• Pharmacologic methods routinely evaluated include:
• low-dose unfractionated heparin (LDUH)
• low-molecular-weight heparin (LMWH)
• warfarin, and
• factor Xa inhibitors such as fondaparinux.