 In dit lectie gaan we de patiën met die kardieke conditieën bespuren. Wat ek ga ek te prusent, is een managment algoritme voor die patiën. Je gaat het vervalieerd wat en maak het beslut en move lang het tree. Before we gete het algoritme, gaan we het met die patiën bespuren. In dit lectie gaan we het vervalieerd wat die patiën bespuren, maar die is ons met wat van die kardieke kardieke. In dit lectie gaan we het verlinkt dat hier met die kardieke kardieke conditieën ondekend jas met die kardieke kardieke. Er gebeurt ondekende patiën en die zijn met die kardieke... en die met die kardieke disease. En het is de salie van die hetgel die ons bemanen die kardieke... wether die beden wit enorme mediek en asydek Wilson serde is... die de kardieke kardieke status van die kardieke kardieke conditieën volkende. The reasons for this are three-fold. We want a good outcome. We want to streamline the process because we don't want to waste time and resources. And then lastly we have to consider some regulatory issues. Let's start with our desire to have a good outcome for our patients. Perioperative morbidity and mortality should be minimized. It's obviously deleterious to the patient, but also in the case of protracted morbidity very costly and resource intensive. My second point speaks to the need for a structured approach so as to streamline the process and avoid unnecessary delays and costs. Useless tests will only delay the surgery and do not lead to any change in the patient's current treatment plan. Not to mention the psychological stress these patients might be put through. And lastly those regulatory considerations. In most surgical units protocols are in place that befit the local structures and resources and these are often used to overall any generic guidelines in publications and in lectures such as these. Always please be familiar with your local requirements and follow these. Regulatory considerations also include patient consent. The patient must be fully aware of the risks and dangers involved in her or his surgery. And it's only by fully considering and comprehending preoperative cardiac evaluation that you as a clinician can inform the patient about these. With all this in mind let's get back to the business at hand. Perhaps a good way to remember the challenges facing the management of these patients to always consider the fact that the heart is a pump. A pump of some reserve capacity. At rest it just patterns along but if strained either by exertion, by disease or by surgery it has to delve into that reserve capacity. If the needs outstrip that reserve capacity morbidity and mortality are sure to follow. It is important to know what the size of that reserve capacity is and by how much our intended surgery will dig into that reserve. If the sums don't turn out well we need to increase those reserves or lessen even cancel the intended demand namely the surgery. Let's take a look at how we'll go about this lecture. The main section of this discussion will centre on a slightly modified management algorithm suggested by the American College of Cardiology and American Heart Association which you may consider employing in your own setting. In order to follow along with this algorithm though some prerequisite knowledge is required. More specifically the algorithm makes mention in order of the following. Critical cardiac conditions, the risk of different types of surgery, the functional or exercise capacity of the patient and finally clinical risk factors. We'll take a look at all of these before embarking on the algorithm itself and after a look at this algorithm I'll briefly discuss how to manage the patient that has prior coronary artery balloon angioplasty or the placement of coronary stents. Before all of this and perhaps starting off the main discussion I will remind you of the American Society of Anesthesiologists or ASA class system of general patient health. It is not part of the algorithm per se but is a good starting point in the preoperative evaluation of all patients. I will end off by looking at the use of ECGs, statins and beta blockers, antihypertensive medication en also the consultation with the physician or the cardiologist. The ASA classification considers all underlying disease and not simply cardiac status. The ASA refers to classes 1 through 6. An ASA class 1 patient is completely healthy except for the disorder requiring surgery. The class 2 patient has mild systemic disease that is well controlled. The class 3 patient suffers from a systemic disease that is poorly controlled or that has resulted in some form of organ dysfunction. The class 4 patient has a disease that is a constant threat to life. The class 5 patient is moribund and not expected to survive without the surgery and finally we have the class 6 patient who is brain dead and needs to be considered for organ donation. I reiterate this class system is important to consider in all patients going to theatre but is not specific to the cardiac patient. In step 2 of the algorithm we consider active cardiac conditions. Now this is our long list and they include unstable coronary syndromes such as unstable or severe angina, stable angina in the sedentary patient and myocardial infarctions in the last 30 days prior to the planned surgery. It also includes worsening or new onset heart failure at the time of the procedural evaluation, significant arrhythmias such as high grade AV block, mobits type 2 AV block, third degree AV block, symptomatic ventricular arrhythmias, supraventricular arrhythmias with an uncontrolled rate, symptomatic bradycardia and newly recognized ventricular tachycardia. Finally it also includes those with severe stenotic valvular disease such as severe aortic stenosis and symptomatic mitral stenosis. It is therefore important to examine your patients and listen to their heart sounds when you consider them for surgery. Now I mentioned in the section above that surgery will dig into the reserve capacity of the heart. There are classification systems that divide different surgeries into their risk for cardiac complications. The basic premise is to consider the hemodynamic effect or fluid shift that the surgery is likely to cause. These are just guidelines and it's important for you to take a minute and consider the intended surgery in each and every case. Think about what fluid shifts including blood will occur. The reserve capacity is very sensitive to both falls and rises in blood pressure. Many factors influence this, blood loss, volume resuscitation, the inflammatory effect of any surgery and the drugs used. Here is the table sorting the surgery into lower, intermediate and high risk. Low risk surgeries have an incidence of less than 1% cardiac complications. Typically we'll consider things such as breast, dental, endocrine eye, simple gynecological, reconstructive and minor orthopedic, minor urological procedures in this group. The intermediate risk group of procedures carries a 1-5% risk of cardiac complication. As the list indicates these include abdominal and carotter procedures, peripheral arterial angioplasty, endovascular aneurysm repair, head and neck surgery, major neurological and orthopedic surgery, pulmonary, renal and liver transplants and major urological procedures. The high risk group of surgeries carries an excess of 5% risk and include all aortic and major vascular surgeries as well as peripheral vascular surgery. Not only are massive demands placed on the heart during these procedures but patients requiring these usually have concomitant cardiac disease. Further down the algorithm we need to find out the functional capacity of the patient and it is crucial in the decision making process. It is important to remember though that the functional capacity refers to the patient as a whole and cardiac disease is not the sole determinant of how active a patient can be. Consider for instance the patient with musculoskeletal disorders such as advanced arthritis or those with lung capacity problems who may have a perfectly healthy heart. With this in mind functional capacity is measured in metabolic equivalents, METs, with one metabolic equivalent equal to the basal metabolic rate. This occurs when lying down or sitting at your desk doing some work. This increases to four metabolic equivalents when climbing two flights of stairs and strenuous jogging or swimming which is up to ten metabolic equivalents. A patient that can reach four metabolic equivalents and higher is in good shape to withstand surgery. They have a reserve to dig into. Too many factors influence those with low metabolic equivalent scores though. With a weak association between score and outcome be vigilant and thoughtful when a patient has a low score. Before we take a look at the management algorithm itself we also need to consider clinical risk factors. Many predictive indices exist such as the predictive cardiac risk index of Lee. Just as many individual risk factors exist but not all have been shown in research to correlate with a worse outcome. The Lee index then lists five risk factors. They are a history of ischemic heart disease, a history of compensated or prior heart failure, insulin dependent diabetes, renal insufficiency with a creatinine of more than 180 millimoles per liter or 2 millimgrams per deciliter and cerebrovascular disease. Factors that are important and need attention but have not been shown to be predictive of cardiac complications are things like obesity, high cholesterol and a family history of cardiac disease. And finally we get to the management algorithm. Your first step is to decide whether the surgery is by nature that of an emergency. If so go ahead and manage the cardiac status both intra and postoperatively. This type of surgery is life saving and includes those procedures with severe morbidity and even mortality should a delay occur. In step 2 that is if the surgery can be delayed the question at hand is whether the patient has any of the above listed cardiac conditions. Remember those, the unstable cognitive syndromes, the cardiac failure, the significant arrhythmias or the severe sternotic disease. So if they have the one of these they need to be evaluated by physician or if available a cardiologist. Considering those that do not have a condition on this list the next step is to decide what category of surgery they are planned to undergo. If the surgery is low risk it can go forward as planned. With the low risk surgery out of the way in other words if the plan surgery is intermediate or high risk the next step is to consider the functional capacity of the patient. Remembering that a low score might not solely be due to cardiac problems. If the patient can reach four or more metabolic equivalents the surgery can go forward. If the patient can reach less than four metabolic equivalents or their functional status is unknown we need to consider the clinical risk factors as described above. If three or more are present consider consultation. If one or two risk factors are present the surgery can proceed unless it is felt that consultation might lead to a change in management. If no clinical risk factors are present it is safe to proceed and there you have it a simple management algorithm. Now the number of patients with prior coronary artery balloon angioplasty and those with connery stents are increasing in number and care should be taken in these patients before embarking on non cardiac surgery. In most all of these cases dual antiplated drugs have been prescribed. The current recommendation is that all patients with bare metal stents should receive clopidogrel for at least a month after placement together with aspirin and in those with drug eluting stents the recommendations are for one year. The possible need for non cardiac surgery within a year is an actual contraindication for the placement of drug eluting stents. We wil take a closer look at aspirin and clopidogrel in a later lecture but I do want to take the time here and discuss a proposed algorithm for these patients and it also comes from the ACC AHA. They divide patients with prior percutaneous interventions into those who've had balloon angioplasty only, those with bare metal stents and those with drug eluting stents. For those who had balloon angioplasty only and it has been less than two weeks since the procedure the suggestion is to delay surgery. For those beyond two weeks the patient can proceed to theatre on aspirin. For those with bare metal stents the cut off is 30 to 45 days. Sooner than this would require delay in surgery and those beyond the cut off time can proceed to theatre again only on aspirin. In the case of drug eluting stents the waiting period is one year. Those beyond a year since replacement can proceed to theatre on aspirin. If the time period is less than a year it is best to delay surgery if at all possible. The prognostic value of routine pre-operative ECGs are unclear. They are of great value if a severe arrhythmia is diagnosed but the literature is vague on who requires this test. Most units rely on ages sole determinant for routine testing based on the fact that the incidence of cardiac disease increases with age. Many units include all patients with a history of cardiac disease or those with any symptom or sign suggestive of cardiac disease as well as those who are to undergo high risk surgery. Most certainly the group of abnormalities to be on the watch out for include major key wave changes, ST segment changes, major T wave changes, mobits type 2 or higher block, left bundle branch block and a fib. These should be referred to a physician or cardiologist. The optimal dosage and timing of perioperative statin use is unknown. But the American College of Cardiology and American Heart Association do listed as good practice to continue the use of statins during the perioperative period. Beta blockade now mentioned has to be made of this sensitive issue. Many publications and recommendations still list the protective effect of the use of beta blockers in the at risk patient. Dosages and titrations to certain heart rates as well as mention of time intervals for treatment were well described. Unfortunately it has recently come to light that there were major irregularities with some of the research projects and the recent literature has suggested that it increases the risk of mortality by about 27%. Be aware of these new findings and question the routine use of beta blockers. In general cardiovascular medication should be continued through the perioperative period. Let's have a look at some of these. Abrupt discontinuation of centrally acting alpha 2 agonists may lead to severe rebound hypertension and stopping ACE inhibitors in patients with congestive cardiac failure can lead to recurrence. Be careful with patients on diuretic therapy which may cause hypervolemia and hyperkalemia. These should be corrected before the surgery. In fact patients with hypertension can have a contracted intravascular space and even a small amount of blood fluid loss during surgery requires monitoring and replacement. The aim of a consultation with a physician or cardiologist is not merely to clear the patient for surgery. Following the algorithm that we have discussed referral for consultation must end with a change in cardiac management so as to improve the reserve capacity of the patient and lessen the risk of surgical morbidity or mortality. The algorithm really aims to identify those patients in whom further investigation be that non-invasive or invasive will lead to a change in management. The cardiologist or physician needs to decide on stress ECGs, echocardiograms or even angiograms. In de next lecture we'll discuss pulmonic conditions.