Cardiac surgery and the general practitioner:
A practical guide of postoperative problems
Taking a history of a patient post cardiac surgery
Examining a patient post cardiac surgery
Auscultation of the heart post cardiac surgery
Medications post cardiac surgery
Driving, flying and foreign holidays
Beating heart surgery and the GP
Coronary artery bypass surgery (CABG) is the most common operation performed in the world today. Even thought the operation is very much routine today it still constitutes major surgery with not insignificant mortality and morbidity. In this review we try to cover the most common postoperative problems that can occur in this patient group after discharge home, ie what the average GP will be consulted with, even if only initially.
Just as in any other medical speciality, history, and a well conducted directed examination are key to accurate diagnosis post cardiac surgery.
Taking a history of a patient post cardiac surgery - The 10 point history
1. What operation has the patient undergone?
2. How long ago was the operation?
3. Was the operation an emergency?
4. How long was the total and postoperative hospital stay? (Usually 5 to 10 days)
5. What cardiorespiratory state was the patient preoperatively?
6. How well was the patient on hospital discharge?
7. Was the patient specifically warned about any symptoms or signs?
8. What medications was the patient given upon discharge?
9. What is the specific complaint of the patient?
10.Ask specifically about sweats, temperature, shortness of breath, cough, pain, weeping wounds and ankle swelling.
Examining a patient post cardiac surgery - The 10 point examination
1. Does the patient look well?
2. Is the patient short of breath?
3. Cold hands and feet indicate poor cardiac output.
4. Warm hands and a bounding pulse indicate sepsis.
5. Examine wounds sternal, leg, arm, and neck
6. Is ankle oedema present?
7. Is jugular venous pressure (JVP) raised
8. Listen to heart sinus, fast atrial fibrillation (AF), and murmurs. Don't rely on radial artery for heart rate.
9. Listen to lungs wheeze, infection, effusion, atelectasis
10.Is epigastrium tender? Gastritis
Auscultation of the heart post cardiac surgery
In patients who have had a CABG the heart sounds are commonly normal, however a 3rd heart sound may be heard with left ventricular failure. Mitral regurgitation may be heard secondary to anular dilation. It is always important to elucidate whether this was present preoperatively. The presence of a valvular murmur preoperatively does not necessarily mean that a valve repair / replacement will have been carried out.
In patients with tissue valves auscultation will rarely detect an abnormality. The presence of a flow murmur should prompt an echocardiogram to evaluate outflow tract obstruction, or valvular degeneration, which occurs 5 - 10 years postoperatively. The presence of a regurgitant murmur should always raise the suspicion of endocarditis in the appropriate clinical scenario or valvular dehiscence. Again echocardiography and possible cardiological evaluation should be undertaken. An apyrexial patient who is well with a normal CRP, ESR and WCC is unlikely to have endocarditis.
In patients with prosthetic valves mechanical valves auscultation can help to determine valvular failure. As with tissue valves the presence of a regurgitant murmur should always raise the suspicion of endocarditis in the appropriate clinical scenario, or valvular dehiscence. Flow murmurs are common on mechanical valves, however echo evaluation is needed to quantify. Mechanical valves that fall silent herald valvar failure (usually valve thrombosis) and should prompt urgent referral to an on call cardiologist, however these patients are usually seriously ill, aiding diagnosis.
Any arrhythmia is possible after cardiac surgery; by far the most common cause is atrial fibrillation. Fast atrial fibrillation (HR greater than 100) is commonly missed as the radial pulse is taken and in the presence of an apical radial deficit, which commonly occurs in fast AF the diagnosis can be missed, hence auscultation of the heart is necessary. The cause of this is multifactorial, and poorly understood, however two important points need addressing. Firstly that the patient doesn’t have hypokalemia, and secondly that the patient is not hypoxic. In GP surgeries obviously chemical pathology and blood gas analysis is not usually available. In practical terms if the patient is eating and drinking normally, and they are not on potassium losing diuretics (eg frusemide alone), and they are not short of breath, and they have a clinically clear chest then these two causes can be eliminated.
Opinion is divided between digoxin and amiodarone. In patients who took beta blockers pre operatively that have been stopped post operatively some reintroduce the beta blockers, albeit at half the previous dose. Sotalol is the preferred beta blocker of choice in most cardiac surgical units.
If atrial fibrillation was not present preoperatively then after 6 weeks treatment, if the patient is in sinus rhythm then they can be stopped. If the patient is still in atrial fibrillation then referral to a cardiologist is warranted, as cardioversion may be an option.
Anticoagulation with warfarin is variably carried out in the UK for postoperative atrial fibrillation. This is because all patients will be on aspirin, which although is not as effective as warfarin with respect to embolic prophylaxis, eliminates the risk of dual therapy and the worry over gastrointestinal bleeds.
Minor leg wound infections are relatively common, 1-10 % of cases, with severe infections of the leg and sternum being relatively uncommon <1%. Excessive wound inflammation, in the absence of infection needs to be recognised to avoid unnecessary antibiotics. Staph aureus remains the most common organism involved, hence the usage of flucloxacillin, or erythromycin in penicillin allergy patients. It is important to ensure that no puss is situated deep in the wound. Any suspicion of deep seated pus needs drainage as antibiotics are unsuccessful in this situation. In assessing sternal wounds sternal stability needs to be assessed. Any evidence of instability may herald mediastinitis and is a reason for referral back to the cardiac surgical unit.
Pleural effusions, are very common post cardiac surgery, especially left sided, secondary to opening the left pleura when harvesting the left internal mammary artery (LIMA). Small effusions should be left to self resolve, larger ones should be either aspirated or have a chest drain inserted. The decision to drain an effusion depends on the respiratory state of the patient, the more short of breath the lower the threshold to intervene.
Respiratory infections are frequent postoperatively, especially left sided. Oral antibiotics usually amoxicillin, or erythromycin in penicillin allergic patients are the most frequently prescribed.. In patients who had prolonged hospital stays pseudomonal infections become more common necessitating the use of ciprofloxacin. Sputum cultures can be very helpful in treating failed courses of antibiotic therapy. Signs of systemic unwell should prompt referral back to hospital for intravenous antibiotic therapy and/or oxygen therapy.
Shortness of breath post cardiac surgery is a common presentation to GPs. The causes can be broken down into haematological, respiratory and cardiac. It should not be forgotten that CABG does not improve dyspnoea, and therefore a comparison with preoperative status is needed.
Anaemia is common postoperatively, and care should be utilised to diagnose the patient who has developed gastrointestinal haemorrhage secondary to the aspirin they are on.
Respiratory causes of shortness of breath that are common postoperatively include pre-existing COAD, chest infection, pleural effusions, and basal atelectasis in the first 10 days postoperatively. Obviously clinical examination will help in elucidating the cause, however a CXR can be invaluable. The left base is the most common site of respiratory complications.
Left ventricular failure, is the most common cause of cardiac induced shortness of breath, as valvular pathology is most likely to have been corrected. ACE inhibition and diuretics remain the main stay of therapy here. Prosthetic valvular dysfunction should always be suspected, although this is rare. Occasionally fast atrial fibrillation will present as breathlessness, with the patient having no sensation of their tachycardia.
Medications post cardiac surgery
This remains one of the most confusing areas for GPs post cardiac surgery, unfortunately usually due to poor communication from the cardiac surgical unit.
Maintaining graft patency
Aspirin is given to all patients who undergo CABG, unless they are aspirin intolerant, in which case dipyridamole, clopidogrel, or warfarin are utilised. Warfarin is frequently given to patients who have undergone endarterectomies, or who are in atrial fibrillation. Aspirin, disopyramide, and clopidogrel are not contraindicated in the presence of warfarin, however a higher bleeding risk will be present. The risk benefit of the combination should be evaluated by the surgeon who undertook the CABG. Increasingly aspirin is being co-prescribed with clopidogrel, due to the perceived reduction in cardiovascular events that will result. Antacids either H2 blockers or proton pump inhibitors (eg omeprazole/lansoprazole - care should be taken with omeprazole as there is a drug drug interaction with warfarin) are given occasionally as gastric prophylaxis.
It is usual to stop all antiplatelet medication 5-7 days pre cardiac surgery, unless severe vascular disease is present. Consultation with the cardiac surgeon performing the case is wise in this situation.
Statin therapy
All patients who were on a preoperative statin, or who are hyperlipidemic should go back on a statin postoperatively, possibly life long. At present there is no evidence that patients with high normal cholesterol who undergo CABG will benefit form statin therapy, however in young patients it is sometimes administered for this. Statin therapy need not be withdrawn preoperatively as the perceived risk of rhabdomyolysis seems to have been overestimated. Common side effects of statin therapy include nausea and abnormal liver function tests. The latter may mean the statin needs to be withdrawn. Obviously cholesterol need to be measured when on statin therapy to ensure that the statin dose is correct, and that combination therapy is not necessary.
Warfarin
Warfarin is always administered to patients with mechanical heart valves, and sometimes to patients who have tissue valves, atrial fibrillation, or have undergone endarterectomies. In patients who have tissue valves, atrial fibrillation, or have undergone endarterectomies an INR above 2.0, preferably above 2.5 is necessary. With respect to mechanical valves the surgeon will recommend a range for the INR to be in. However mechanical valves in the aortic position should not have an INR below 2.0, and in rhe mitral position the INR should be above 2.5.
Patients on warfarin pre cardiac surgery should have it stopped 3 to 5 days before the operation. If the patient has a mechanical valve hospital admission will be necessary for heparinisation, however in the presence of lone atrial fibrillation no therapy is usually instigated in the 3 to 5 days before the operation.
The role of screening for Helicobacter pylori, and its eradication is uncertain at present. Hospitalisation secondary to gastrointestinal hemorrhage in patients on warfarin post cardiac surgery is known to be associated with Helicobacter pylori.
Antianginal medications
These are all stopped postoperatively. Some surgeons utilise a nitrate for a short period postoperatively. Calcium channel blockers, usually diltiazem or amlodepine are frequently given postoperatively to counter radial artery spasm, and not for its anti-anginal effects.
Anti-hypertensive medications
It is common for patients blood pressure to be low for the first few weeks postoperatively, hence the stopping of preoperative anti-hypertensives upon hospital discharge. These invariably will need to be reintroduced at some point postoperatively. ACE inhibitors are becoming first line therapy especially in patients with poor left ventricular function.
Diuretic therapy
Diuretic therapy is commonly given to patients post cardiac surgery. Preoperative diuretic therapy usually predicts the need for long term use, however in patients post valve surgery the dose can frequently be reduced. Patients who undergo CABG are frequently put on frumil and or frusemide. This is usually in patients with poor left ventricular function or those who have been on cardiopulmonary bypass – as opposed to being done off pump. The majority of patients who were not on preoperative diuretics can have them stopped at 6 weeks postoperatively (usually in their outpatients appointment).
Management of patients with tissue valves can be divided up into anticoagulation and follow-up. Different cardiac surgeons manage tissue valves differently with respect to anticoagulation. Some employ no anticoagulation, some just aspirin, and others warfarin. Patients are usually anticoagulated for a period of between two and six months.
The use of the radial artery, has recently become more common secondary to the perceived benefit of arterial revascularisation. Wound infections of the non dominant forearm are uncommon, however sensory changes in the forearm and hand are relatively common. Forearm claudication is unusual. Patients are usually treated with three months of calcium channel blockers usually diltiazem or amlodipine.
Skin is usually closed with an absorbable sutures, meaning no sutures need to be removed. A few surgeons utilise clips. The removal of the clips requires the dedicated clip remover to reduce any discomfort felt by the patient.
Neuropsychological dysfunction and fine movements
Raynolds phenomenon post operative
Neuropsychological dysfunction and fine movements
The use of cardiopulmonary bypass (heart lung machine) is known to affect all aspects of cerebral and cerebellar function. This usually manifests itself as loss of concentration, reduced mental agility, memory impairment, and uncoordinated fine movements of the hands. Symptoms usually recover over the ensuing months, however recovery may be incomplete. With the introduction of off pump CABG, with no touch of the aorta, these complications may be dramatically reduced in future.
Pericarditis post cardiac surgery, is well described but infrequent. Severe cases resulting in Dresslers syndrome (pleural effusions and pericarditis) may require steroid treatment, however usually a short course of a non steroidal is sufficient.
(Localised pericarditis is a common term what probably implies a myocardial infarction, which should always be ruled out before a diagnosis of pericarditis is made).
Postoperative urinary tract problems remain surprisingly uncommon. UTIs are most commonly secondary to urinary catheterisation, which all patients undergo. Long term, urethral stricture can result from traumatic catheterisation, and the profound hypotension that can occur during cardiac surgery.
Over 95% of patients undergoing CABG have the left internal mammary artery (LIMA) mobilised, to anastomose to the left anterior descending (LAD) coronary artery. This can result in an area of numbness, and or hypersensitivity of variable size over the left anterior hemithorax. This may not recover normal sensation, and patients should merely be reassured.
Spreading the chest via a median sternotomy can result in traction injuries to the brachial plexus. This manifests itself in the form of ulnar nerve / T1 neurology. This is usually tingling/numbness along the medial border of the hand, which usually spontaneously recovers.
Raynolds phenomenon post operative
Raynolds phenomenon can occur postoperatively. This may be due to either the ulnar /T1 nerve injury described above or the withdrawal of the preoperative calcium channel blockers and other vasodilators.
All patients who have implanted valves should have endocarditis prophylaxis as detailed in the current UK guidelines. It should not be forgotten that patients who have had patch closure of an ASD or VSD, or prosthetic replacement of part of the aorta should also have antibiotic prophylaxis.
Recurrent angina occurs in 1-5 % of patients in the 1st year and up to 30 % of patients by 10 years. Patients should be reinvestigated in a standard manner, usually by a cardiologist.
Driving, flying and foreign holidays
These should all be avoided for at least 8 weeks assuming a smooth postoperative course. This allows the sternum to heal and the neuropsychological sequelae to improve. Medical insurance should be recommended for all foreign travel.
Does the fact that the patient had beating heart surgery make any difference to the GP
It should make no difference to their management after discharge.