Quality ControlIntroductionThe main aims and objectives of this assignment are to explore different types of artefacts of ECG and Spirometry. I will also explain why it is important to ensure that high quality control should be in place while performing ECG or spirometry on patients to reduce future artefacts. An artefact is something measured that is not naturally present but occurs as a result of the physiological procedure. The common sources of artefacts include; electrical noise, motion and inefficient image optimisation from the operator.
Quality control is a procedure or set of procedures intended to ensure that performed medical service sticks to a defined set of quality criteria and meets the requirements of patient’s safety, comfort and satisfaction (Rouse 2015). Quality control in healthcare is important to the healthcare industry and patient. This ensures that patient-oriented care is provided and helps the operators to gain an accurate result of the patient’s health. ElectrocardiographyElectrocardiograms (ECGs) are frequently recorded in the clinic as a non-invasive method to collect diagnostic information about the heart’s rhythm and electrical activity.
(Dekie, 2017) Artefact on the electrocardiogram can result from a variety of internal and external causes from muscle tremors to dry electrode gel (Bouthillet, 2015). The factors that can affect ECG quality are operator error/poor optimisation, environmental noise and patient.Below is an ECG of a patient that we tried to get the best quality recording possible. From this recording, I can see that this patient has pacemaker fitted. The main artefact caused by the patient is the muscle tremor which is a type of motion artefact. This happens when a patient is not relaxed or is shivering while the ECG is taking place. This is maybe because the patient is really nervous about the procedure and it is probably their first time having it done so they don’t know what to expect. The muscle tremor artefacts are frequently known to cause ECG abnormalities that may mimic cardiac disease. This is what the ECG looks like when the patient is tensed. Figure 2. ECG result of a patient showing muscle tremor artefact. An irregular spiky interference is shown within the limb leads. From this result, it is obvious that tremor is present in lead I and II. Lead I indicate tension in the right and/or left arms then Lead II shows tension in the left leg and/or right arm. Therefore, as a result, this can be misinterpreted on the computer and provide a false report of the patient’s heart condition including ventricular tachycardia or supraventricular tachyarrhythmia which are abnormally fast heart rhythm (Matthias and Indrakumar 2014). In order to reduce the interference in the recording in future, it is important to check that patient’s arms and shoulders are relaxed and not clenched, also that patient is not talking and that they are not tensed or shivering. Another factor that can affect the ECG quality is the operator error. An example of operator error is a misplacement of limb electrodes. The operator places limb electrodes on the patient’s shoulder rather than their wrists. Figure 3. ECG result showing inverted limb leads and baseline wander. A negative deflection of the QRS wave is shown in Lead I, II, III in this recording which means that the positions of the limb electrodes are incorrect. The waves in the limb leads are inverted. It also shows a baseline wander, this can be caused by patient movement and heavy breathing. The QRS wave must be always positive in all leads because each lead should view the heart from the angle of its positive electrode.The operator is the main source for this artefact as it is their lack of knowledge and practice that has led them to place the limb electrodes further away from the wrist.The adverse effect of this artefact is that this can simulate dextrocardia when the heart is situated on the right side of the body. This interference can be eliminated in future by always placing the limb electrodes on the patient’s wrist and ankles. Moving the electrodes furthest away from the limb can cause a variation on the appearance of ECG. Therefore, it is best to avoid it unless the patient’s limb is amputated. To reduce baseline wander, the patient’s breathing should be steady and ensure that all tabs are in good contact with the skin. Technical artefact means physical properties are used which are unique to the procedure. It is the result of purposeful human action in order to produce an artefact. It is not naturally occurring. Therefore, to produce a technical artefact, the patient was given a mobile phone to hold while the ECG was taking place. Small regular peaks and a wide, fuzzy baseline is shown in the limb and chest leads of this recording. This is known as AC Interference. This comes from an external source and it has picked up other electrical signals in the surroundings. This result shows that there is a presence of other electrical devices nearby. It shows a frequency of 50Hz interference. The adverse effect of this recording is that ventricular fibrillation which means no cardiac output and it is the most important shockable cardiac arrest rhythm. (Burns, 2018)This interference can be reduced by keeping away or turning off all the non-essential electrical devices near the ECG machine for the duration of the test. It is important to repeat the ECG if this artefact occurs to get an accurate result as possible. However, if the artefact cannot be fully removed then it is best to annotate the recording as Best Possible Trace’ to show that attempts have been made to improve quality. At all times, it is important to review the ECG on the screen first before printing the actual ECG for completeness and good quality. If it is hard to view on the screen, then review the recorded ECG on paper to decide if it is a high-quality ECG. SpirometrySpirometry is the most common pulmonary function test. It is a test used to help diagnose and assess certain lung conditions by measuring the various lung volumes that the patient can expel from the lungs. It is performed using a device called a spirometer, which is a small machine attached by a cable to a mouthpiece (NHS, 2018). Spirometry can be used to measure lung function to help make a definitive diagnosis. Certain lung conditions such as asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis and pulmonary fibrosis can be picked up and monitored using spirometry. Spirometry can keep a track of the lung disease progression.The common factors which affect the quality of spirometry are incomplete inhalation or exhalation, slow start to maximal effort, lack of forced effort during exhalation, extra breath during the blow, coughing during the blow and poor posture while performing spirometry test.Abnormal spirometry is divided into restrictive and obstructive ventilatory patterns.The restrictive disease is where all lung volume is reduced. The FVC (Forced Vital Capacity) and FEV1 (Forced expiratory volume in one second) are reduced and FVC is reduced more than FEV1, so the ratio is normal to high. The obstructive disease is when the airways are blocked due to airways narrowing. The FVC and FEV1 are reduced so FEV1/FVC ratio under 80% is always obstructive disease. What quality controls can be made: Patients must be observed and encouraged throughout the procedure. Record at least three acceptable and valid results which are repeatable. There should be three maximal effort curves with the same size and shape. This spirogram shows variable expiratory effort. The poor effort is seen as a dip in this recording during the first 1.5-3 seconds of the test. This result can be misinterpreted as obstructive impairment due to falsely reduced FEV1 and FEV1/FVC ratio. This recording can be optimised to reduce the interference by encouraging the patient to blow as hard and fast as they can and to keep blowing out, so the result will level out smoothly at the end rather than dipping. This artefact is caused by the patient therefore, patients must always be observed and encouraged throughout the procedure. Figure 6. Spriogram showing sub-maximal blastThis spirogram shows a poor start in blowing out, which has resulted in spirometry measurements being made early in the test leading to the incorrect recording of the patient. In this recording, the peak on the curve is reduced every time the person has repeated the test. This shows that weaker the blast, the lower the peak of the curve. The adverse effect of this artefact is that it can simulate as obstructive impairment. Therefore, to eliminate this interference in future, it is best to train and tell the patient to blow the air out harder and much faster from the lungs. However, the values can also be affected by age, height, sex and ethnic origin of the patient. It is important to take these into consideration before analysing the result. Figure 7. This spriogram shows that this person has tried multiple times to try their best to get a quality result. From this recording, it is obvious that during the first couple of tries, this person wasn’t fully exhaling. They also stopped before the volume of air in the lungs were fully emptied. Therefore, there is no peak flow of the curve and shows a reduced FVC and FEV1. It is also evident that this person has lacked a forced effort during exhalation because the curve has decreased too soon. There also seems to be having a disruption in the middle of the curve, this is because the person might have coughed or laughed in between the spirometry test. Therefore, it doesn’t show a smooth transition from the start of the blow to the end. There is a slight increase after the dip on the last curve which means the person must have taken an extra breath during the blow so the FEV1/FVC ratio will be incorrect. Therefore, this isn’t a high-quality spirometry result at all so the patient must repeat the procedure to get the accurate result.This result can be optimised to eliminate the interference by explaining the complete procedure to patients and encourage them to fully exhale and don’t stop early as early termination can give an incorrect result. They should blow until they are told to stop. They should take the deepest breath possible because otherwise this can be misinterpreted as restrictive impairment and therefore, it won’t be a valid result. Figure 8. Spriogram showing an accurate result according to the age and height.This recording shows a much better result compared to previous examples because it has three acceptable traces and both FVC and FEV are repeatable. It starts from the baseline and it increases sharply to one second and then gradually decreases showing the end of exhalation. ConclusionIn conclusion, artefacts can occur if electrocardiograms and spirometry are not performed properly and can have an effect on the patient’s treatment. When performing ECG, it is important that lead placement and patient preparation are done in a correct way to avoid getting inaccurate results. It is also important to check that the patient is confident with spirometry and they fully exhale to gain a quality result. Good quality control should be in place as it can have an impact on the improved result. The artefacts can occur due to the patient, operator or technical fault so it is vital to be aware of all the possible situations and be able to prevent them easily.