Principles of Cardio-Pulmonary Bypass&Myocardial Protection Strategies :Principles of Cardio-Pulmonary Bypass&Myocardial Protection Strategies Dr Ravi Sankar Venuturumilli, MD Chief Cardiac Anaesthetist & Intensivist email: venuturu@yahoo.co.in


Cardiopulmonary Bypass :Cardiopulmonary Bypass Diversion of blood away from both Left & Right sides of the heart and lungs Has become an integral component of Cardiac Surgery In addition, CPB is used in Periods of asystole Inadequate Cardiac Output (VAD) When lungs cannot maintain appropriate physiologic Gas exchange (ECMO)


Cardiopulmonary Bypass :Cardiopulmonary Bypass Types: Total Routine in Cardiac Surgery Partial Blood flows in RA, RV & Pulmonary Circulation where heart continues to beat and pt needs to be ventilated Used in Vascular surgery


Rationale for the Use of Cardiopulmonary bypass :Rationale for the Use of Cardiopulmonary bypass During open heart surgery, CPB provides the surgeon with a clear field for cardiac manipulation and maintenance of pulmonary and hemodynamic stability. The objective of the heart- lung pump is to provide enough flow to maintain a sufficient cardiac index for tissue perfusion. The addition of cardioplegia allows the surgeon to work in a motionless and bloodless field. The addition of hypothermia to CPB has been standard practice since Bigelow demonstrated improved tolerance of the entire organism to ischemia accompanied by hypothermia.


Differences Between Adult and Paediatric Cardiopulmonary Bypass :Differences Between Adult and Paediatric Cardiopulmonary Bypass Major differences exist between adult and pediatric cardiopulmonary bypass (CPB), stemming from anatomic, metabolic, and physiologic differences in these 2 groups of patients.


CPB & Anesthetist :CPB & Anesthetist Although CPB typically constitutes a less busy time for anesthesiologists than the periods before and after it, many routine tasks are greatly facilitated by the presence of a member of the anesthesia care team, and some emergency situations require Anesthetist’s constant presence. Included among the routine tasks are: Monitoring perfusion pressure and systemic perfusion and treating pressure disturbances with vasopressors and vasodilators


CPB & Anesthetist :CPB & Anesthetist routine tasks Monitoring anesthetic depth and administering anesthetic drugs as needed Assuring the presence of adequate neuromuscular blockade and administering additional muscle relaxants as needed Monitoring urine output and determining the possible need for osmotic or loop-acting diuretics or adjustments in systemic blood flow or pressure Monitoring the adequacy of myocardial electrical silence during the aortic cross clamp period


CPB & Anesthetist :CPB & Anesthetist routine tasks Monitoring the adequacy of myocardial decompression Using transesophageal echocardiography to assist the surgeon with air evacuation maneuvers or with venous cannula or coronary sinus catheter positioning Monitoring patient temperature during cooling and rewarming Making blood transfusion decisions Monitoring anticoagulation and administering heparin


Historical Landmarks :Historical Landmarks Gibbon first described and used a mechanical extracorporeal oxygenator, which he termed the heart-lung machine. On May 6, 1953, Gibbon performed the first successful open heart surgery in the world using a heart-lung machine while repairing an atrial septal defect. In 1954, Lillehei first reported the effective use of extracorporeal circulation in repair of CHD using cross circulation with the patient's parent functioning as the oxygenator. Subsequent attempts to use the heart-lung machine to help correct congenital heart defects were met with high morbidity and mortality rates until Barratt-Boyes (1971) and Castaneda (1974) attempted correction using hypothermic circulatory arrest.


Circulation during CPB :Circulation during CPB


Components of CPB circuit :Components of CPB circuit


Components of CPB circuit :Components of CPB circuit Venous Drainage Bicaval – SVC/IVC Two Staged – in RA Reservoir Pumps Pump prime – Made of balance salt solution, colloids, mannitol, Bicarb, Heparin Oxygenators Bubble – now obsolete Membrane


Components of CPB circuit :Components of CPB circuit Heat exchanger Arterial inflow Cardiotomy suction Ventricular venting Micropore filters Ultra filtration


Components of Cardiopulmonary Bypass :Components of Cardiopulmonary Bypass


Preparing for CPB :Preparing for CPB Anticoagulation – Heparin (Unfractionated) Monitoring Anticoagulation Vascular Cannulation Arterial Venous


Complications of Vascular Cannulation :Complications of Vascular Cannulation Aortic dissection Arterial cannula malposition Cannula reversal Massive gas embolization Venous air-lock


Management of CPB :Management of CPB Initiation Pump flow Acid base balance Temperature Cardioplegia


How to initiate CPB? :How to initiate CPB? Cannula is inserted into right atrium to drain venous return Venous blood passes into venous reservoir under gravity Oxygenated and CO2 removed usually by membrane oxygenator Heat exchanger controls blood temperature A 40 micron filter removes air bubbles Pump returns blood into aorta distal to a cross clamp Suction used to remove blood from operative field Returned to patient via cardiotomy reservoir


Cardiopulmonary bypass :Cardiopulmonary bypass


Membrane Oxygenator :Membrane Oxygenator


Arterial Filter :Arterial Filter


Cardio-pulmonary Bypass Prime :Cardio-pulmonary Bypass Prime Aim: to have enough fluid volume to prime the circuit, whilst not over diluting the total hemoglobin pool.


Cardio-pulmonary Bypass Prime :Cardio-pulmonary Bypass Prime Tailored individually Aim for a final, combined Hb (i.e. Patient + pump) of 8-9 gm/dL (Hct: ~25) 3 Basic Types of Prime: 1. Using no blood (Preferable) 2. Using fresh heparinised blood. 3. Using fresh citrated blood or packed cells.


CPB Pump Flow :CPB Pump Flow Must be adequate to meet the oxygen consumption Varies with temperature Nomograms for perfusion flow based on temperature Blood pressure depends on pump flow and SVR MAP 40-50 mm hg in unaltered cerebral auto regulation >60 mm hg - if impaired organ flow e.g. Carotid artery stenosis Nonpulsatile / Pulsatile Flow


Acid Base Balance maintenance :Acid Base Balance maintenance ABG checked periodically to correct the Acid Base balance a stat pH stat No significant difference in the management


CPB – Temperature :CPB – Temperature Thermoregulation is impaired during anesthesia for cardiac surgery Hypothermia Cerebral metabolism and blood flow ? Brain protected from hypoxic injury Side effects: Coagulopathies Poor wound healing ? Metabolism – delayed awakening Mild hypothermia (~34°) is optimal


Use of Hypothermia :Use of Hypothermia Effect on Metabolic Rate In a patient undergoing CPB, hypothermia helps protect against injury caused by the compromised substrate supply to tissues resulting from reduced flow. This protection occurs because of a reduction in metabolic rate and decreased oxygen consumption. The metabolic rate is determined by enzymatic activity, which in turn depends on temperature. The decrease in metabolic rate is not the only factor involved in hypothermic protection. The actual safe period of hypothermic CPB is longer than the period predicted by a sole reduction in metabolic activity.


Use of Hypothermia :Use of Hypothermia Effect on pH The effect of hypothermia on pH is mediated by its effect on the ionization constant of water and, therefore, its effect on the ionized-to-nonionized ratio of metabolic substrates. In ischemia, the intracellular pH decreases because of the accumulation of hydrogen ions. Hypothermia affects this by decreasing the metabolic rate, then by increasing the ionized-to-nonionized ratio. In addition, the transformation of a semiliquid cellular membrane to a semisolid membrane is postulated to decrease calcium influx.


Use of Hypothermia :Use of Hypothermia Effect on Central Nervous System Multifactorial. Decreasing the metabolic rate Decrease the release of glutamate, which is involved in CNS injury during CPB. A negative effect of hypothermia on brain function is the loss of autoregulation at extreme temperatures, which makes the blood flow highly dependent on extracorporal perfusion.


Techniques of Hypothermia :Techniques of Hypothermia Currently, two surgical techniques are used in congenital heart surgery, namely, Deep hypothermic circulatory arrest (DHCA) Hypothermic low-flow bypass (HLFB)


Deep Hypothermic Circulatory Arrest :Deep Hypothermic Circulatory Arrest DHCA provides excellent surgical exposure by eliminating the need for multiple cannulas within the surgical field and by providing a motionless and bloodless field. Surgical technique Initiate the cooling phase prior to institution of CPB by simple cooling of the operating room environment. After systemic heparinization and cannulation, initiate CPB. Monitor body temperature via esophageal, tympanic, and rectal routes.


Deep Hypothermic Circulatory Arrest :Deep Hypothermic Circulatory Arrest Inflammatory response Activation of the inflammatory pathway leads to serious complications, morbidity, and mortality. Several strategies have been used to modify the inflammatory response. These include: Use of heparin-coated CPB circuit to reduce the inflammatory response Modifying the blood cardioplegia solution has been investigated as a means of reducing inflammatory-mediated myocardial injury after intracardiac repair. Since neutrophils may mediate the local inflammatory response in the heart, a leukocyte-depleted blood cardioplegia (LDBC) has been postulated as a means for improving myocardial protection during CPB. Modified ultrafiltration.


Hypothermic Low-Flow Cardiopulmonary Bypass :Hypothermic Low-Flow Cardiopulmonary Bypass The finding that DHCA was associated with neurologic morbidity has led researchers to investigate the use of HLFB. This technique allows continuous low-flow perfusion to the organs during the operation, which may lead to an increase in oxygen supply, better nutrient supply, and better achievement of homogeneous hypothermia during bypass. Recent trials comparing the 2 methods have reported lower rates of neural dysfunction in the group of patients undergoing HLFB.


Pathobiology of CPB :Pathobiology of CPB Cardiopulmonary Bypass Initiating factors Contact activation Ischemia reperfusion endotoxemia Immune system activation Complement Cytokines Coagulation / Fibrinolysis Endothelium Cellular immune system SIRS


Routine Monitoring during CPB – from patient :Routine Monitoring during CPB – from patient Electrocardiograph (ECG) Systemic arterial pressure (Invasive) Central venous pressure Core body temperature Urine output should be monitored using a freely draining urinary catheter. Local protocols should dictate the frequency of measurement.


Monitoring associated with the cardiopulmonary bypass circuit :Monitoring associated with the cardiopulmonary bypass circuit The following should be monitored continuously: Venous oxygen saturation of the blood in the venous return line of the cardiopulmonary bypass circuit Arterial oxygen tension or saturation of the blood in the arterial line of the cardiopulmonary bypass circuit Continuity of the fresh gas flow to the oxygenator using an in-line flow meter or rotameter Oxygen concentration of the fresh gas flow to the oxygenator using an oxygen analyser with alarms and sited after the oxygen blender and vaporiser if used


Monitoring associated with the cardiopulmonary bypass circuit :Monitoring associated with the cardiopulmonary bypass circuit Continuous Monitoring Blood flow rate generated by the arterial pump of the cardiopulmonary bypass circuit Arterial line pressure of the cardiopulmonary bypass circuit Cardioplegia delivery line pressure when cardioplegia is delivered using the heart lung machine Temperature of the blood in the cardiopulmonary bypass circuit Temperature of water in the heater/cooler system


Monitoring associated with the cardiopulmonary bypass circuit :Monitoring associated with the cardiopulmonary bypass circuit Continuous Monitoring Activated clotting time (ACT) to confirm anticoagulation should be measured after heparinisation and before cardiopulmonary bypass. During cardiopulmonary bypass the ACT should be measured at regular intervals. Filtrate volume should be measured when a haemofilter/concentrator is being used.


Monitoring associated with the cardiopulmonary bypass circuit :Monitoring associated with the cardiopulmonary bypass circuit The following measurements should be available at a near patient facility. Local protocols should dictate the frequency of measurements: Blood gases. Red cell concentration (hemoglobin or haematocrit). Serum potassium Blood sugar


Monitoring associated with the cardiopulmonary bypass circuit :Monitoring associated with the cardiopulmonary bypass circuit The following measurements should be available at an on site facility: Clotting studies Serum calcium Serum lactate Serum magnesium


Myocardial Protection Strategies :Myocardial Protection Strategies Myocardial Protection The term "myocardial protection" refers to strategies and methodologies used either to attenuate or to prevent post ischemic myocardial dysfunction that occurs during and after heart surgery.


Myocardial Protection Strategies :Myocardial Protection Strategies Principles of Myocardial Protection The main principles of myocardial protection are the reduction of metabolic activity by hypothermia the therapeutic arrest of the contractile apparatus and all electrical activity of the myocytes by administering cardioplegic solution (e.g. depolarizing of the membrane potential by high potassium blood cardioplegia)


Therapeutic innovations for myocardial protection :Therapeutic innovations for myocardial protection 1950 Bigelow WG studied the application of hypothermia to cardiac surgery in canines 1953 Swan H showed that hypothermic arrest (26°C) in humans provided a bloodless field for operating 1955 Melrose DG & Bentall HH introduced the concept of reversible chemical cardiac arrest in canines 1956 Lillehei CW detailed a method for delivering hypothermic crystalloid cardioplegia by cannulating coronary arteries 1957 Lam CR one of the earliest known uses of the term "cardioplegia“


Therapeutic innovations for myocardial protection :Therapeutic innovations for myocardial protection 1958 Gerbode F& Melrose DG used potassium citrate to induce cardiac arrest in humans 1960 McFarland JA challenged the safety of the Melrose technique; changed from potassium arrest to intermittent aortic occlusion or coronary artery perfusion for myocardial protection 1964 Bretschneider HJ developed a sodium-poor, calcium-free, procaine-containing solution to arrest the heart 1964 Sondergaard KT adopted Bretschneider's cardioplegic solution and was one of the first to routinely use it for myocardial protection in clinical practice 1973 Gay WA, Ebert PA credited with revival of potassium-induced cardioplegia; demonstrated that potassium solution could arrest a canine heart for 60 minutes without cellular damage


Therapeutic innovations for myocardial protection :Therapeutic innovations for myocardial protection 1973 Roe BB demonstrated that "the modalities of cardioplegia, hypothermia, and capillary washout" provided effective myocardial protection 1974 Tyers WA demonstrated that an infusion of cold blood to keep the myocardial tissue below 4° provided 90 minutes of ischemia in animals 1975 Hearse DJ emphasized preischemic infusions to negate ischemic injuries in rats; this formula became known as St. Thomas solution no. 1 1975 Braimbridge MV one of the first to use St. Thomas solution no. 1 clinically 1976 Effler DB recommended simple aortic clamping at operating room temperatures


Therapeutic innovations for myocardial protection :Therapeutic innovations for myocardial protection 1979 Buckberg GD introduced the use of blood as the vehicle for infusing potassium into coronary arteries 1984 Akins CW utilized technique of hypothermic fibrillatory arrest for coronary revascularization without cardioplegia 1986 Murray CE noted that brief periods of ischemia and reperfusion enable the heart to withstand longer periods of ischemia 1991 Lichtenstein SV & Salerno TA reported clinically beneficial results using continuous, warm blood cardioplegia


Elective Cardiac Arrest & Cardioplegia :Elective Cardiac Arrest & Cardioplegia Myocardial Protection: K+ induced arrest and asystole using cardioplegia solution (CPS) Hypothermia induced by CPS and cold Ringers solution applied topically Maintained by regular application and use of Ringers slush around the myocardium.


Cardioplegia Solution :Cardioplegia Solution Cardioplegia solution generally contains: K+ HCO3¯ Ca2+ Glucose CPS can be crystalloid, colloid or blood based. They can be delivered at a variety of temperatures and pressures dependent upon the patient and procedure.


Cardioplegia Solution :Cardioplegia Solution Blood Cardioplegia Base Solution (500 ml) Sodium – 77 mmol Potassium – 40 mmol Magnesium – 15 mmol Chloride – 149 mmol Glucose – 11 mmol To this is added 25 ml of 8.4% Sodium Bicarbonate and 28 mmol of Monosodium L-Aspartate. The induction dose is mixed in a ratio of 1:4, Base solution: blood. The maintenance dose is delivered at 1:6, Base solution: blood.


Cardioplegia Circuit :Cardioplegia Circuit


CARDIOPLEGIC TECHNIQUES :CARDIOPLEGIC TECHNIQUES Cardioplegia has become the gold standard of myocardial protection for practically every type of heart surgery during which the ascending aorta must be clamped. By reducing energy consumption and thus oxygen demand, ischemia tolerance of the heart can be significantly prolonged. Without such measures, irreversible ischemic damage begins to occur in the human heart after only 20 min, whereas when current techniques of myocardial protection are used, arrest times of more than 4 or 5 hours may be tolerated without irreversible damage.


CARDIOPLEGIC TECHNIQUES :CARDIOPLEGIC TECHNIQUES Cardioplegic solutions contain a variety of chemical agents that are designed to arrest the heart rapidly in diastole, create a quiescent operating field, and provide reliable protection against ischemia/reperfusion injury. There are two types of cardioplegic solutions: crystalloid cardioplegia blood cardioplegia. These solutions are administered most frequently under hypothermic conditions.


Cold Blood Cardioplegia :Cold Blood Cardioplegia Cold blood cardioplegia, widely employed throughout the world, is the cardioplegic technique most commonly used. It is usually prepared by combining autologous blood obtained from the extracorporeal circuit while the patient is on cardiopulmonary bypass with a crystalloid solution bicarbonate (buffers), and potassium chloride. The Citrate-Phosphate-Dextrose (CPD) is used to lower the ionic calcium, the buffer is used to maintain an alkaline pH of approximately 7.8, and the final concentration of potassium is used to arrest the heart (approximately 30 mmol/L).


Cold Blood Cardioplegia :Cold Blood Cardioplegia Prior to administering blood cardioplegia, the temperature of the solution is usually lowered with a heat exchanging coil to between 12°C and 4°C. The ratio of blood to crystalloid varies among centers, with the most common ratios being 8:1, 4:1, and 2:1. This in turn affects the final hematocrit of the blood cardioplegia infused. For example, if the hematocrit of the autologous blood obtained from the extracorporeal circuit is 30, these ratios would result in a blood cardioplegia with a hematocrit of approximately 27, 24, and 20, respectively.


Cold Blood Cardioplegia :Cold Blood Cardioplegia The rationales for using blood as a vehicle for hypothermic potassium-induced cardiac arrest include: It can provide an oxygenated environment. It can provide a method for intermittent reoxygenation of the heart during arrest. It can limit hemodilution when large volumes of cardioplegia are used. It has an excellent buffering capacity. It has excellent osmotic properties. The electrolyte composition and pH are physiologic. It contains a number of endogenous antioxidants and free radical scavengers. It can be less complex than other solutions to prepare.


Methods and delivery of cardioplegic solutions. :Methods and delivery of cardioplegic solutions.


Separation from CPB :Separation from CPB Preparation Re-warming Spontaneous myocardial activity Ventricular fibrillation – Defib Heart block – Pacing ABG, Electrolytes, Hct to be optimized Ventilation Started Trendlenburg position to remove intra cardiac air


Strategies for weaning :Strategies for weaning Beating heart examined Visually TEE Poor contractions – inotropes ? SVR - Vasopressors LV volume status optimized


Termination of CPB :Termination of CPB As the pt meets the criteria for separation from CPB Perfusionist gradually clamps the venous tubing ? blood flow to the reservoir ? venous return to the heart Arterial pump head is slowed, gradually filling the heart Appropriate preload is established Pulsatile arterial wave achieved CPB terminated


Weaning from Bypass :Weaning from Bypass While on full support via venous occlusion start volume loading Ra > 5 mmHg LA > 4 mmHg PA < 1/2 systemic pressure Ventilating


Volume Requirements after CPB :Volume Requirements after CPB Maintain adequate pressures Maintain or improve haematocrit Control bleeding using appropriate fluids/drug combinations


Management following CPB :Management following CPB Reversal of anticoagulation Protamine Management of post CPB ventricular dysfunction


Anticoagulation for Cardiopulmonary Bypass :Anticoagulation for Cardiopulmonary Bypass Anticoagulation and heparin reversal Pediatric and neonatal patients undergoing CPB for cardiac surgery are more prone to coagulopathy in the early postoperative period. Contributing factors include hemodilution, immaturity of the coagulation system, depletion of platelets and other hemostatic proteins, and the complex nature of the operations performed, which often include multiple suture sites and, therefore, an increased number of potential bleeding sites.


Anticoagulation for Cardiopulmonary Bypass :Anticoagulation for Cardiopulmonary Bypass Anticoagulation To avoid forming thrombi in the CPB machine, heparin is administered prior to cannulation. Heparin is chosen because it is a fast-acting anticoagulant and its action can be inhibited rapidly by protamine. Heparin activates antithrombin III, which inhibits thrombin activity. Heparin is stored in the vascular endothelium and smooth muscle, contributing to heparin rebound, which is observed after discontinuation of CPB and heparin reversal. Clearance of heparin also is determined by hepatic and renal function.


Anticoagulation for Cardiopulmonary Bypass :Anticoagulation for Cardiopulmonary Bypass Anticoagulation Typically, a loading dose of 200-300 U/kg of heparin is given and then heparin activity is monitored by measuring activated clotting time (ACT) and heparin levels. Physicians at some centers administer 300 U/kg, check to see if this leads to an ACT of 450-480 seconds, then administer supplemental heparin based on subsequent ACT levels. The use of only one of these monitoring methods may not reflect the full degree of anticoagulation. ACT levels can be affected by factors unrelated to heparin concentration, including the patient's hematocrit and temperature.


Anticoagulation for Cardiopulmonary Bypass :Anticoagulation for Cardiopulmonary Bypass Heparin reversal Protamine binds to heparin and releases antithrombin III. One method of administering protamine is to administer 1-1.3 mg for each 100 U of heparin administered. This method does not take into account the half-life of heparin or its clearance from circulation. Other methods include ACT-heparin dose-response curves, direct measurement of heparin levels, and use of the heparin-protamine titration.


Anticoagulation for Cardiopulmonary Bypass :Anticoagulation for Cardiopulmonary Bypass Adverse effects of protamine Release of histamine, which can lead to a decrease in systemic vascular resistance True anaphylaxis, which is mediated by antiprotamine immunoglobulin E (IgE) and observed primarily in patients with prior exposure to protamine (e.g. neutral protamine Hagedorn [NPH] insulin) and in patients with fish allergy Thromboxane release, which leads to pulmonary vasoconstriction and bronchoconstriction


Anticoagulation for Cardiopulmonary Bypass :Anticoagulation for Cardiopulmonary Bypass Strategy to counteract post-CPB bleeding Bleeding after CPB is not unusual. Identify any sources of obvious surgical bleeding since this is the most common cause of post-CPB bleeding. Assess the adequacy of the protamine dose. If the dose appears to be sufficient, the next most common cause of bleeding is platelet dysfunction, and platelet infusion is warranted, even if the platelet count is within reference range. Administration of aprotinin can decrease blood transfusion requirements in patients undergoing repeat surgeries and in patients who are cyanotic. Desmopressin has antifibrinolytic activity and acts as a kallikrein inhibitor.


Post CPB Ventricular dysfunction – Etiology :Post CPB Ventricular dysfunction – Etiology Exacerbation of preexisting dysfunction & relative intolerance to asystolic arrest Inadequate myocard. Protection Ischemia / Infarction Reperfusion injury Unmasked ventricular dysfuncion Uncorrected lesions


Management of post CPB LV-Dysfunction :Management of post CPB LV-Dysfunction Identify Treatment course (if possible) Optimize forward flow Heart rate - ? or ? Rhythm - ± Pacing Manipulate loading conditions & inotropic or lucitropic conditions Treat acidosis If RV failure – optimize specific afterload determinants, i.e. PO2, PCO2, pH, airway/intrathoracic pressure, N2O, GTN Mechanical Circulatory support systems


Therapeutic Strategy for managing Heart Failure :Therapeutic Strategy for managing Heart Failure


Donor or Pump Blood Post-Op :Donor or Pump Blood Post-Op


“Undesirable” Features of CPB :“Undesirable” Features of CPB Hematology / Haemostasis Use of suction Blood contact with CPB circuit Perfusion imbalances Haemodilution Prolonged cross-clamp times Use of relatively large amounts of donor blood and blood products Emboli


Complications of CPB :Complications of CPB Potential for exposure to communicable diseases Pale skin Sleep deprivation Moderate levels of stress, sometimes very high levels Post operative Neuropsychiatric symptoms


Modified Ultra filtration (MUF) :Modified Ultra filtration (MUF) The increase in extra vascular fluid which tends to accompany CPB, is in part due to increased capillary permeability, as a result of the inflammatory response initiated by CPB Perioperative ultra filtration and more specifically post CPB modified ultra filtration (MUF), can be used to decrease total body water thereby minimizing these deleterious effects Our aim is to remove 100ml/kg of filtrate and this usually requires a period of 12 to 20 minutes in the neonatal population. Time taken and amount of filtrate removed will vary in larger children.


Modified Ultra filtration (MUF) :Modified Ultra filtration (MUF)


Newer Methods to Overcome complications :Newer Methods to Overcome complications NIRS can be used to monitor cerebral oxygenation to protect cerebral tissue during CPB


Newer Methods to Overcome complications :Newer Methods to Overcome complications The Cardiopulmonary Bypass Monitor The Problem Emboli are small bubbles or particles in flowing blood Emboli can cause mental deficits & stroke (particles are thought to do more damage) Emboli occur in heart-lung (CPB) machines during open heart surgery The Solution Device can detect micro emboli in CPB Particulate micro emboli can be treated with anti-coagulants and brain protecting medications


Slide 80:The Beat Goes On