Cardiac Surgery PDF

Cardiac Surgery Presented by Omar AL-Rawajfah, RN, PhD  Lecture Outlines Coronary Artery Bypass Graft Surgery Minimally invasive cardiac surgery Transmyocardial Laser Revascularization Cardiac valve surgeries – Cardiac valve replacement – Cardiac valve r...

Cardiac Surgery Presented by Omar AL-Rawajfah, RN, PhD  Lecture Outlines Coronary Artery Bypass Graft Surgery Minimally invasive cardiac surgery Transmyocardial Laser Revascularization Cardiac valve surgeries – Cardiac valve replacement – Cardiac valve repair Assessment for patient undergoing cardiac surgery Educational perpetration Nursing diagnoses Collaborative management – Intraoperative phase – Postoperative phase – ICU – Intermediate cardiac care unit Multidisciplinary outcomes 2  History 1967 the first CABAG surgery in the USA First open-heart surgery procedure in Jordan in 1970 First heart-valve replacement in the country in 1972 First coronary artery bypass in Jordan in 1973 3  History Dr. Daoud Hanania performed the first open- heart surgery procedure in Jordan in 1970 The first heart-valve replacement in the country in 1972 as well as the first kidney transplant in the Arab world in the same year The first coronary artery bypass in Jordan in 1973. In 1985 he performed the first ever successful cardiac transplant in the Middle East and the Arab world at the King Hussein Medical Center in Amman, Jordan 4  Indication The ACC/ AHA CABG guidelines state CABG is the preferred treatment for: – Disease of the Left Main Coronary Artery Disease of all three coronary vessels (LAD, LCX, & RCA). – Diffuse disease not amendable to treatment with a PTCA. Factors associated with bypass surgery – Age, previous heart surgery, LtV EF, percentage of stenosis, number of coronary blood vessels that need grafting 5 Coronary Artery Bypass Graft Surgery Saphenous vein was used to bypass diseased coronary artery Arteries has become more popular for bypassing blocked coronary arteries Internal thoracic artery (internal mammary artery) is the most common used artery Other arteries that have been used are gastroepiploic artery, inferior epigastric artery, less commonly radial artery Suphenous vein is associated with lower 5-year patency rate than arteries 85%-95% of internal thoracic artery graft are patent 10 years after the surgery Gastroepiploic artery is commonly used to by pass blockages in the RCA or posterior descending artery 6 Proximal LAD Stenosis 7 8 9 SPY Intra-operative Imaging System 10  Minimally invasive cardiac surgery Involves using small incisions between the ribs instead of using the traditional median sternotomy approach Usually done with the assistance of microscopic technology Usually done for patient with single vessel disease of the LAD that is not amenable to PTCA or stent During this procedure, the heart not stopped but the HR is reduced using B-blockers or Ca-channel blocker Special stabilization equipment is used to allow the surgeon to do the graft appropriately Usually, patient experience less surgical complications, less incisional pain, less hospitalization, and recovery more quickly 11 Off-pump Coronary Artery Bypass Surgery Beating heart surgery Usually, used minimal invasive direct coronary artery bypass grafting technique Used to reduce the neurological complication associated with the bypass machine Used for patient with low EF of the LtV 12 Median Sternotomy Approach 13 Transmyocardial Laser Revascularization Newly invented approach that include creating small channels through ischemic areas of the heart It is believed that these channels provide a means for blood to flow from the ventricle through the endocardium, the myocardium, and toward the epicardial surface of the heart It is also believed that these channels improve oxygenation of the myocardium through the angiogenesis Eligible patient – Unstable angina pain that refractory to intervention – Prior cardiac CABAG – Multiple cardiac intervention – Maximum medication treatment The outcomes of the procedure looks good and improvement of pain and activity was reported 14 15 Transmyocardial laser revascularization 16  Valvular Disease Valvular stenosis – Narrowed orifice that creates a partial obstruction of blood flow Valvular insufficiency or regurgitation – Valve is incompetent or leaky blood flow backward Diagnosis – Health history – Murmur – Physical examination – Echocardiogram – Cardiac catheterization 17 Mitral Stenosis Caused by rheumatic heart disease Because of narrowing of the valve → ↓blood flow from Lt atrium to Lt ventricle →↓cardiac output →↓ systemic perfusion →back flow to pulmonary circulation → pulmonary hypertension → pulmonary edema → dyspnea, orthopnea Lt atrial dilation cause atrial fibrillation in 40% - 50% of affected patient 18 Mitral Insufficiency Caused by rheumatic heart disease, degenerative changes Because of stretching of the leaflets of the valve → blood flow from LtV to Lt atrium → LtV hypertrophy → LtV overload →back flow to pulmonary circulation → pulmonary hypertension → pulmonary edema → dyspnea, orthopnea 19 Aortic Stenosis Caused by rheumatic heart disease, bicuspid valve, or calcification degeneration Because of narrowing of the valve → ↓blood flow from LtV systemic circulation → angina and syncope Sever stenosis will lead to LtV hypertrophy and increased Intraventricular pressure Late stage they complain of dyspnea, orthopnea 20 Aortic Insufficiency Caused by rheumatic heart disease, aneurysm of the ascending aorta Because of incomplete colure of the valve → blood flow from the aorta into the LtV during the diastole →↓forward output and ↑ LtV pressure and volume →back flow to pulmonary circulation → pulmonary hypertension → pulmonary edema → dyspnea, orthopnea Patient usually have ↓diastolic pressure and wide pulse pressure Angina may occure 21 Balloon Valvuloplasty  Valve Reconstruction Most valve reconstruction procedures are performed on the mitral valve. Advantages – Eliminates need for long-term Anticoagulation – Decreases risk of thromboembolism & endocarditis – Decreases need for reoperation – Increases survival rates – Not successful in aortic valve disorders (insufficiency & restenosis) Reconstruction procedures are more likely to be successful if performed early in the course of the disease, before left ventricular function deteriorates. Valve Reconstruction  Cardiac Valve Repair Repair can be done for valve insufficiency or stenotic valves Mostly done for valve insufficiency Insufficient valve can be repaired by inserting an annuloplasty ring; the ring is sewn to the valve annulus this procedure → called valve annuloplasty Tears in valve leaflets can be patched with pericardial tissue Ruptured papillary muscle can be reattached to the ednocardium 80% of Mitral valve dysfunction can be repaired compared to small percentage for aortic valve 25  Surgical Treatment for Valvular Disease  Mitral Stenosis o By reconstruction (Commissurotomy) the fused commissures are surgically divided, calcified tissue is debrided.  Mitral Insufficiency o By reconstruction the valve leaflets are repaired. o Anticoagulation is not usually needed after valve repair unless an annuloplasty ring is used, In such cases, Anticoagulants are given for only 3 months. o If reconstruction cannot be accomplished, valves are replaced Annuloplasty 27 A ring annuloplasty 28  Cardiac Valve Surgery Cardiac valve diseases are mainly caused by rheumatic heart disease, degenerative disease, or endocarditis Lt heart valves are diseased more (aortic valve & mitral valve) than the Rt side This is because of greater pressure on the Lt side of the heart Surgery is indicated when symptoms of ventricular dysfunction start to appear 29  Surgical Treatment for Valvular Disease Done through a median sternotomy incision with the use of cardiopulmonary bypass. Two major types of prosthetic valves are available; mechanical & biological.  Surgical Treatment for Valvular Disease Patients with a long life expectancy may receive mechanical valves because they are particularly durable. Older patients may receive biological valves because less calcification & deterioration occur in older people, long-term durability is less important, & the risk of anticoagulation may increase with advancing age. Biological valves are indicated for patients who are unable to comply with an anticoagulation regimen, for those in whom a long-term anticoagulation regimen is contraindicated, & for women who plan to become pregnant (the anticoagulant Warfarin crosses the placental barrier). Patients in chronic atrial fibrillation undergoing mitral valve replacement frequently receive long-term anticoagulation therapy even with a biological prosthesis.  Cardiac Valve Replacement 2 types of valves are used: 1. Mechanical valves – They need lifelong anticoagulant therapy Caged ball design Tilting disc design – Single disc design – Bileaflet valve design 32 Caged ball design 33 Single disc design 34 Bileaflet valve design 35  Cardiac Valve Replacement 2. Bioprosthetic valves – Usually used for elderly – Durable for 7 – 14 years Porcine: pig aortic valve Bovine: constructed from pericaridal tissue of calves Homografts: valves retrieved from human heart within 24hrs of cardiac arrest The patient, cardiologist, & the surgeon determine the type of the valve based on location of the valve, age, lifestyle, past medical history Mechanical valves are selected if a long life expectancy is likely (e.g., > 15 years) 36 Porcine: pig aortic valve 37 Bovine aortic valve 38 Allograft, a human aortic valve 39 Valve Replacement and Repair 40  Preoperative Phase Patient and family need special preparation to decrease level of anxiety Educational preparations – Tour of the ICU waiting room, intermediate care unit – Have the patient talk and communicate with other patients recovering from the same surgery – Expectation before the surgery: Diagnostic test Skin preparation NPO at least 8 hrs Deep breath & coughing exercise, leg exercises – Expectation during the surgery Expected time of the surgery Type of the procedure Family waiting room 41  Preoperative Phase – Expectation after the surgery: Name and location of the ICU External devices such as ventilator, NGT, ECG electrodes, central lines, chest tubes, & foley catheter Expected procedures such as endotracheal suctioning, blood administration, activity progression Expected ICU noise & family involvement Additional preparations include – Results of preoperative laboratory test should be within normal range (e.g., blood chemistry, CBC, PT, PTT, ECG, chest x-ray, blood type) – Shower with antibacterial soap – Essential medication may be given early morning 42  Nursing Diagnoses Preoperative phase: – Anxiety – Knowledge deficit Intensive Care Phase – Pain – Decreased cardiac output – Fluid volume deficit – Alter breathing pattern – Infective family coping Intermediate care phase – Ineffective airway clearness – Pain – Decrease cardiac output – Activity intolerance – Knowledge deficit 43  Collaborative Management Intraoparative phase: – Several large IV access is established – ECG electrodes are placed – Central line & arterial line, foley catheter, endotracheal tube are inserted – Skin cleansed with povidone-iodine – Patient’s sternum is opened at the same time saphenous vein is exposed – Cannulation of the Rt atrium & Aorta and attached to the cardiopulmonary bypass machine – Cardiopulmonary bypass machine oxygenates the blood and return it to the body – Machine is usually primed with balanced electrolyte solution 44  Collaborative Management Intraoperative phase: – Heparin is administered throughout the bypass machine – Core body temperature is reduced to 28°C to 32°C – Each 1Cº decreases 7% of the metabolic demands – The heart is arrested with cooled cardioplegic solution – Heart temperature reached 4Cº and stopped by injection of high concentrated K solution at the root of aorta – Cardioplegia solution is injected either continuously to aortic root or 15-30min or whenever the cardiac activity is resumed Post-operative cardiac depression Arrhythmia Decrease cerebral perfusion Irreversible platelets dysfunction 45  Collaborative Management Intraoparative phase: – New techniques used normothermic blood cardioplegia with or without core body temperature reduction Less post operative bleeding Better post operative LFV function More frequent spontaneous return of normal sinus rhythm – Surgeon starts the operation while the heart is arrested – Heprinzation is reversed by protamin sulfate – Chest tube is placed mediastinum and pericardial – When the surgery is completed machine is removed and heart activity 46 is resumed Cardiopulmonary bypass machine 47 Cardiopulmonary bypass machine 48 49  Effects of Cardiopulmonary Bypass The interface between blood & bypass circuit (nonphysiological surfaces) leads to: – Increased capillary permeability, thus the patient becomes edematous. – Hemodilution, thus Hb, HCT & coagulation factors are decreased. – Altered coagulation. – Increased risk of microemboli. – Increased systemic vascular resistance (SVR) related to Catecholamine secretion during bypass surgery. Postoperative Care  Collaborative Management Postoperative ICU phase: – Usually need 2 nurse for the first 30 – 45 min – Initial VS, cardiac rhythm, hemodynamic parameters, chest tubes outputs are recorded – Neurologic status: Pupils reaction Consciousness Orientation – Ventilation and oxygenation Patients usually intubated and mechanically ventilated Usually FiO2 at 50%, TV at 10 – 15 mL/Kg, RR at 10-12, PEEP can be added at low level PSO2, ABGs are monitored Endotracheal suction is done when necessary with hyperoxygenation and hyperventilation before the suction Usually patient is extubated within 2-4 hrs After extubation patient is paced on face mask 50% with semifowler position, then weaned to nasal cannula 6L Incentive spirometry is encouraged at least 10 times per hr Encourage deep breathing & cough exercise with pillow support over the incision 52  Collaborative Management Postoperative ICU phase: – Hemodynamic Monitoring Fluid replacement is necessary to optimize preload Intropes may be infused to enhance contractility It is recommended to keep the mean arterial pressure between 65-75 mmHg for the first 12 hrs Hypertension may be managed with nitorglycerin infusion Right atrial pressure is maintained by fluid replacement – Mechanical Support Intra-aortic balloon pump is usually inserted through the femoral artery Usually timed by the ECG waveform to inflate during diastole & deflate during systole It improve oxygenation and blood flow to sensitive organs such as brain, kidneys and heart It acts by decreasing both the afterload and preload 53  Postoperative Phase Prevention of Hypothermia: a common side effect o Core temperature decline as warmed blood begins to circulate to the periphery & heat transfer to the surrounding tissues. Prevent Shivering: o Shivering often occurs between 90 & 180 minutes after ICU admission. o Shivering increases metabolic rate, oxygen consumption, CO2 production, & myocardial workload – Increasing the room temperature & using radiant heat, blankets, or a warming blanket. – Rewarming should occur slowly to prevent hemodynamic instability due to rapid vasodilation.  Postoperative Phase Monitoring for Systemic Inflammatory Response Syndrome (SIRS) SIRS is a natural defense mechanism that is initiated when tissue or vessels are injured. An entire “body” inflammatory response may occur after CABG surgery. As a result of the endothelial damage, increased capillary permeability & alteration in coagulation. Symptoms & Signs include fever, tachycardia, tachypnea, & an increased white blood cell count. Nursing responsibilities focus on early detection of embolic events in any system, especially the cardiovascular, pulmonary, & renal system.  Postoperative Phase Preventing Pulmonary Complications – Effective oxygenation is monitored using pulse oximetry with intermittent ABG sampling. – Positive end-expiratory pressure (PEEP) help keeping the alveoli open & improve oxygenation. – Prepare for weaning from mechanical ventilation – Use of incentive spirometry, encourage physical mobility. – Auscultation of breath sounds at frequent intervals, diminished breath sounds may indicate atelectasis. – Observation work of breathing, tachypnea, use of accessory muscles, bronchodilator therapy may indicated  Postoperative Phase  Controlling Pain Pain results from the chest or leg incision, the chest tubes, rib spreading during surgery & care activities. The ICU environment may accentuate the pain physiologically because of light & noise, & psychologically because of separation & fear. Pain often stimulates the sympathetic nervous system, increasing heart rate & blood pressure, decrease chest expansion, increase atelectasis & retention of secretions. Angina after CABG may indicate graft failure. Nursing Management: assessment of the patient’s pain using a pain scale; administration of analgesics based on the reported pain intensity; provision of adequate pain relief as reported by the patient; & alleviation of factors that enhance pain perception, such as anxiety & fear.  Postoperative Phase Monitoring for Arrhythmias – Sinus Tachycardia is very common & may result from Sympathomimetic drugs, SIRS, hypovolemia, fever, & pain. – Sinus Bradycardia may occur, In many cases, preoperative Beta blocker may be the cause. – Premature atrial contractions PACs are usually Rt electrolyte disturbances, ischemia or infarction, or hypoperfusion, treated by replacement of Potassium & Magnesium. – Atrial Fibrillation, Heart Block & , VT arrhythmias are also possible. – Refers to ACLS guidelines for management  Postoperative Phase Preventing Neurological Complications  Neurologic Assessment – Assesses the level of consciousness, motor and sensory ability, & CN injury. – The family of the patient may be helpful in detecting any subtle changes. – Confirmation of a stroke can be performed with CT scan or MRI of the head. – Thrombolytic therapy cannot be used after surgery in the patient who has just had CABG surgery because of bleeding concerns.  Postoperative Management Monitoring Postoperative Bleeding – It is recommended that if the patient is receiving Clopidogrel, it should be stopped 5 to 7 days before surgery. – Monitor chest tube output. – Rewarm the patient. – Administer blood products.  Postoperative Management  Monitoring Postoperative Bleeding  If the chest tube output continues to be greater than 200 mL/hour, Protamine sulfate is the first level of intervention & given at 1 mg for every 100 units of Heparin to reverse the effects of heparin.  Monitor PT & PTT  Rewarming is important as coagulation cascade cannot function properly at hypothermic temperatures  Infusion of platelet, fresh frozen plasma (usually 4 to 6 units/infusion), coagulation factors such as cryoprecipitate (factors I & VIII) & factor VII  Surgical reexploration with chest tube bleeding > 500 mL/hour.  Bleeding Complication: Cardiac Tamponade Cardiac tamponade: Excessive accumulation of fluid or blood in pericardial space resulting in increasing pressure on the right atrium & ventricle Warning signs: – Decreased chest tube output – Decreased cardiac output & BP – A-line demonstrates pulsus paradoxus. Increase & equalization of pressures Definitive diagnosis: Echocardiogram  Postoperative Phase Preventing Renal Complications – Autodiurese with depletion electrolytes – Slight metabolic acidosis may be present – Decreasing urine output The focus of interventions is to remove excess fluid while protecting metabolic & cardiac function. Fluid or Loop diuretics (eg, Furosemide) are the usual first-line drugs Preventing Endocrine Complications – Strict glycemic control – Adrenal insufficiency may occur in patients receiving Steroids at regular intervals before surgery  Postoperative Care Preventing Gastrointestinal Complications - (NPO) for up to the first 8 hours, with a nasogastric tube & small amounts of ice or water decrease the possibility of nausea, vomiting, & aspiration. Controlling BP – Maintain between 120 & 170 mm Hg Wound Care Assessment of operative site Monitoring for Infection o SIRS or overshoot rewarming o If the fever more than 38°C persists for more than 48 to 72 hours, infection should be considered. o Use of prophylactic Antibiotics  Patient Teaching and Discharge Hospitalization after CABG usually 4 to 7 days. Discharge planning begins on admission. Discharge medications typically include – Aspirin, -Blocker, ACE inhibitor, & Statin Smoking cessation interventions Risk factor reduction Incision care Neurologic changes Medication education Follow-up physician appointments Intra-aortic balloon pump 66  Intra-Aortic Balloon Pump Counterpulsation  IABP is designed to increase coronary artery perfusion pressure (aortic root pressure) & blood flow during the diastolic phase of the cardiac cycle by inflation of a balloon in the thoracic aorta:  The desired results are: Increases coronary artery perfusion pressure Increases oxygen supply to myocardium Decreases afterload & LV work Decreases myocardial oxygen consumption Decreases excessive preload Improves cardiac output (contractility).  Indications & Contraindications of IABP  Indications for IABP therapy:  Cardiogenic shock after MI  Left ventricular failure after cardiac surgery  Severe Unstable Angina  Mitral regurgitation/postinfarction ventricular septal defect  Short-term bridge to cardiac transplantation  Contraindications Aortic valve insufficiency Severe peripheral vascular occlusive disease Any previous aortofemoral or aortoiliac bypass graft Aortic Aneurysm  Cardiogenic Shock Cycle Figure 18-17 Cycle leading to Cardiogenic shock  Goals of IABP  Increasing Oxygen supply to the Myocardium – The inflation of a balloon during the diastole in the thoracic aorta increases the retrograde blood flow (toward aortic root) in the thoracic aorta which increases coronary artery blood flow & oxygen delivery to the myocardium.  Goals of IABP  Decreasing Left Ventricular Work The deflation of the balloon, at end of diastole (just before systolic ejection), acutely decreases aortic pressure by causing sudden evacuation of blood (increase antegrade blood flow; away from aortic root, encourages empting of the Lt ventricle). The deflation decreases the impedance to ejection (afterload) & left ventricular work, & myocardial oxygen consumption.  Improving Cardiac Output  Equipment Features/ Procedure  Insertion methods of the IAPB catheter:  Percutaneous insertion (most common)  Alternative is direct insertion into the thoracic aorta through median sternotomy incision (restricted to previous cardiac surgical patients). Once in place (in thoracic aorta), the catheter is attached to a machine that has three basic components: a monitoring system, an electronic trigger mechanism, & a drive system that moves gas in & out of the balloon. o The monitoring system can display patient’s ECG & arterial pressure waveform. o The standard trigger mechanism for the balloon pump is the R wave that is sensed from the patient’s ECG. This trigger signals the beginning of each cardiac cycle for the drive system.  Equipment Features/ Procedure Other possible triggers include systolic arterial pressure or pacemaker spikes on the ECG. The drive system is the actual mechanism that drives a pressurized gas (Helium) through a catheter into & out of the balloon by alternating pressure & vacuum.  Timing (Conventional & Real timing) – Conventional: uses the arterial waveform as the triggering mechanism to determine both inflation & deflation of the balloon. – Real timing: uses the same point of reference (the dicrotic notch on the arterial waveform) for balloon inflation but uses the ECG signal as the trigger for balloon deflation.  Equipment Features/ Procedure  Timing (Conventional & Real timing) Real timing: uses the ECG as the trigger signal for balloon deflation. The QRS complex is recognized as the onset of ventricular systole, & balloon deflation occurs at this time. Triggering off the R wave allows for balloon deflation to occur at the time of systolic ejection & not before (as with conventional timing). This timing mechanism is more effective in patients with irregular heart rhythms because balloon deflation occurs on recognition of the R wave (systolic ejection). The main difference between the two timing methods is balloon deflation & the triggering mechanism used.  Intra-Arterial Waveforms & Timing Point A indicates the beginning of systole. Point B (dicrotic notch) represents aortic valve closure indicating the beginning of diastole. The balloon should be inflated with the beginning of diastole (at point B) & not before it as systole is not completed. Balloon should be deflated just before systole at the end of diastole (point A) Figure 18-20 Figure 18-19 Arterial waveform, with A representing the point of Cardiac cycle of the left heart with aortic, left ventricular balloon deflation before the systolic upstroke, and B (LV), and left atrial pressure waveforms. AC, aortic valve representing balloon inflation at the dicrotic notch, at closure; AO, aortic valve opening; D, diastole; MC, mitral diastole valve closure; MO, mitral valve opening; S, systole.  Assessment and Management  Cardiovascular System: vital signs, cardiac output, heart rhythm & regularity, urine output, color, & mentation. Early recognition & treatment of dysrhythmias are crucial for effective IABP support. The left radial pulse should be frequently assessed. – A decrease, absence, or change in character of the left radial pulse may indicate that the balloon has advanced up the aorta & may be partially obstructing or has advanced into the left subclavian artery.  Assessment and Management  Extremities should be checked hourly for Pulses, Color, & Sensation The presence of the balloon catheter in the femoral or iliac artery predisposes the patient to impaired circulation of the involved extremity. o Any deterioration in the affected extremity should be reported to the physician. Severe arterial insufficiency (loss of pulses in the distal extremity, pain & pallor) necessitates removal of the catheter. The affected extremity needs to be kept relatively immobile or use a knee immobilizer to remind the patient to avoid hip flexion; – Flexion of the hip of affected extremity may kink the catheter & impair balloon pumping – The head of the bed also should not be elevated more than 30 degrees.  Assessment and Management  Monitoring the Pulmonary System Many patients on IABP therapy require intubation & ventilatory assistance. Some of these patients may have respiratory insufficiency secondary to fluid overload associated with HF. The immobile, intubated patient is always at risk for respiratory infections & the development of atelectasis. Turning the patient is appropriate provided modifications are implemented to keep the extremity cannulated by the balloon catheter straight. Daily chest radiographs are needed to follow pulmonary status & to inspect IV catheter placement. The position of the balloon catheter also can be deter-mined in this manner.  Assessment and Management  Monitoring the Renal System – Patients in cardiogenic shock or severe LV failure are at risk for the development of acute renal failure. – In the shock state, the kidneys suffer the consequences of hypoperfusion; therefore, urine output & quality should be monitored closely. – Serum BUN, creatinine, & creatinine clearance are monitored daily to assess renal function. – Any acute, dramatic drop in urine output may be an indication that the catheter has slipped down the aorta & is obstructing the renal arteries.  Assessment and Management  Use Heparin Therapy – To prevent possible thrombus formation around the catheter Use a gradual Weaning (gradual decrease in the assist ratio from 1:1 to 1:2 & so on until the minimum assist ratio is achieved). o The minimum amount of time should be 30 minutes. o During this time, the patient must be assessed for any change in hemodynamic status. o An increase in heart rate, a decrease in blood pressure, & a decrease in cardiac output indicate a deterioration in hemodynamic status. In this case, weaning should be discontinued temporarily & therapy should be adjusted before another weaning attempt.  Indications for Weaning Patient From IABP To ensure patient safety when weaning him or her from IABP, the nurse should be alert for the following: – Hemodynamic stability – Cardiac index (CI) greater than 2 L/min. The normal range for CI is 2.5 to 4 L/min/m2 – Pulmonary artery occlusion pressure less than 20 mm Hg – Systolic blood pressure greater than 100 mm Hg – Minimal requirements for vasopressor support – Evidence of adequate cardiac function – Good peripheral pulses  Indications for Weaning Patient From IABP To ensure patient safety when weaning him or her from IABP, the nurse should be alert for the following: – Adequate urine output – Absence of pulmonary edema – Improved mentation – Evidence of good coronary perfusion – Absence of ventricular ectopy – Absence of ischemia on the ECG – Severe vascular insufficiency – Deteriorating, irreversible condition  Complications  Neuropathy in the catheterized extremity  Arterial insufficiency (most common)  Arterial perforation or occlusion.  Balloon leakage & rupture: o Presence of bright red blood or dried blood in the catheter or helium delivery line o Gas alarm sounds & Signs of embolic event o Managed by: Immediate removal of the catheter by the appropriate personnel, Before removal: Turn pump off, Clamp the line, Place the patient on left side in Trendelenburg position.  Collaborative Management Postoperative ICU phase: – Ventricular assist devices Placed at the end of operation when the CO is severely altered and the intra-aortic balloon pump was not effective in maintaining adequate CO Patient may receive Rt ventricular, or Lt ventricular, or biventricular assist devices For Rt ventricular assist device, one port is placed in the Rt atrium and the other port in the pulmonary artery Rt ventricular assist device assists the heart by divert the blood from the Rt ventricle to the pulmonary artery For Lt ventricular assist device, one port is placed in the Lt atrium and the other port in the Aorta Lt ventricular assist device assists the heart by divert the blood from the Lt ventricle to the Aorta Biventricular assist device 84 combines both Ventricular assist device (VAD) 85 86  Collaborative Management Postoperative ICU phase: – Cardiac Rhythm Potential causes of disturbances include electrolytes disturbances, hypothermia, edema of the conduction pathway or damage of the conductive pathway Usually pacing wires are placed on the heart at the end of the procedure Pacing wires can be used for temporary pacing in case of emergencies Usually temporary pacing is set on demand mode Because the wires are contacted with the epicardium, precautions should be taken to avoid microshocks In case of cardiac arrest temporary pacing is usually enough to establish a cardiac rhythm, if not CPR is started CPR is done by reopening the chest quickly and do direct 87 cardiac massage  Collaborative Management Postoperative ICU phase: – Fluid Status Patients are commonly fluid depleted because of: 1. Vasodilatation caused by releasing bradykinin & serotinin 2. Fluid leaks into the interstitial tissue 3. Blood loss 4. Chest tubes drainage 5. Post operative diuresis result from mild hyperglycemia Hypovolemia is treated by infusion of Normal Saline or Ringer’s lactate, or Hetastarch (Hespan) Fluid amount is determined by the hemodynamic status of the patient Chest tube drainage more than 200mL per hr should be reported directly to the surgeon Consider blood transfusion 88 if Hb less than 8mg/dL  Collaborative Management Postoperative ICU phase: – Restoring of Temperature Patient are cooled by the heat exchanger to mild hypothermia to minimize metabolism cellular O2 requirements Sever hypothermia can cause ventricular dysrhythmias, myocardial depression, ↑blood viscosity and systemic vascular resistance Rewarming is started at the end of the procedure by covering the patient’s head, thermal blankets, infrared lamps If the patient developed sever shivering Morphine sulfate is given to reduce the side effect of shivering Shivering increases the body’s metabolic needs by 300 to 800% , CO2 production, HR, & systemic vascular resistance 89  Collaborative Management Postoperative ICU phase: – Renal Status I & O is recorded Urine output should be at least 0.5mL/Kg per hr K level should be closely monitored K replacement should be considered when K level less then 4.0 mEq/L – Pain In side the OR Propofol (Diprivan) is given infusion at rate of 10 – 50 µg/Kg per min titrated gradually to allow the patient to wake up Morphine sulfate is given for the first 24hr Oral pain killer is usually prescribed – Activity Turning position every 2 hrs Setting the first day Ambulation begins as soon as patient is free from hemodynamic monitoring lines 90  Collaborative Management Postoperative Intermediate Cardiac Care Phase: – Neurologic Status Neurologic assessment every 8 hr – Cardiovascular ECG monitoring for 3 – 5 days postoperatively Atrial dysrhythmias are common (20 – 40%) – Pulmonary Status Aggressive pulmonary care is needed to clear out the secretion Incentive spirometry is encouraged ever hr Medastinal or pleural chest tube can be removed in the ICU or in the intermediate unit when the output is less than 100mL/8hr 91  Collaborative Management Postoperative Intermediate Cardiac Care Phase: – GI Status NGT is usually discontinued next day of the operation If the gastroepiploic artery is used NGT is kept for 2 days H2 blocker may be used Liquids are allowed after extubation Low-fat, cardiac diet is given when tolerated Assess for constipation – Renal Status I & O monitoring Diuretics may be prescribed to mobilize interstitial fluids K level should be monitored – Skin Incisions should be assessed daily Chest tube incision is covered by sterile dressing Leg incision is kept until oozing is stopped It is NOT recommended to clean the incision with NS if there is no need for that 92  Collaborative Management Postoperative Intermediate Cardiac Care Phase: – Infection S & S of infection should be monitored Antibiotics are given as needed – Activity Patient is encouraged to gradually increase his daily activity Stair climbing is initiated before discharge Shoulder and arm exercises are started 93  Multidisciplinary Outcomes Maintaining adequate oxygenation Maintenance of hemodynamic stability Restoration of fluid and electrolyte balance Achievement of optimal activity level Maintenance of nutritional status Prevention of complication Self-management of therapeutic regimen 94 Questions and answers 95