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Word count:2186An assignment to Review and Evaluate the use of Contrast including pharmacology and safety.Introduction The use of iodinated contrast agents (ICA’s) began around the 1920s starting of in clinical practice with the use of sodium iodide being present (Bottinor, Polkampally and Jovin, 2013). Furthermore, due to the exponential rise for using diagnostic imaging in recent decades, ICA’s are more fundamental and have significantly increased (Beckett, Moriarity and Langer, 2015). Therefore, this has greatly aided in their continued production which caused a result of their critical changes towards the structure, providing us with much safer and more effective compounds (Tuffrey-Wijne et al., 2013). ICA’s are now recognised as the most popular and successful. They are most commonly used today, with estimates from the year 2012 indicating that around 76 million were issued per year around the world (Pasternak and Williamson, 2012). There can also be many threats that are associated with the use of ICA’s that have not yet been eliminated, this may lead to many reactions continuing to occur (Tuffrey-Wijne et al., 2013). According to Tuffrey-Wijne et al, those interested with the handling of ICA’s must be familiar with the signs and characteristics, and any side effects that may occur. They must also be able to recognise any serious reactions quite quickly and be able to treat them safely (2013). This piece of work looks into the clinical and pharmacology effects associated with ICA’s as well as looking into the management and any hazards. It will also highlight the safety of contrast agents in current clinical practice and aim to show what ICA’s are and how they are used efficiently.Iodinated contrast agents (ICA’s) in radiography are one of the more commonly used forms of media, they are also used in almost any area in the body so that is becomes easier when analysing natural or pathological circumstances (Singh and Daftary, 2015). Typically, ICA’s are safe with mild effects occurring now and then. However, at times it could lead to life threatening reactions to occur which is quite extreme (Ibid). ICAs may be administered in a variety of ways, including through the use of an orifice, intramuscularly, intravenous or through ingestion (Pasternak and Williamson, 2012). A few popular imaging modalities where ICA’s are used are in magnetic resonance imaging (MRI), fluoroscopy and computed tomography (CT); additionally, the use of ICA’s in these modalities are present in a variety of different procedures. For example, GI tract investigations, cholangiography, sialo grams, intravenous urography, venography and angiography (Nouh and El-Shazly, 2017). It was suggested by Pasternak and Williamson that the ability of an ICA to be able to attenuate an X-ray it must depend on the iodine molecules which are located within the tissue that is being imaged, and it is inversely related towards the X-rays energy that was used in the imaging (2012). Therefore, the form and the amount of an ICA that is needed for inspection will have to be determined by the characteristics of the imaging that is required; additionally, an ICA with a higher concentration is able to increase the attenuation of the X-ray beam, providing a better image of the structures and the organs that are being examined (Ibid). it is proposed that the higher concentrations include higher osmolality and viscosity leading them to be more toxic (Yeh et al., 2017). One good example of an ICA is Niopam as it is available in a number of strengths and it is used to explore kidneys, joints, blood vessels, bladder, urinary tract, spine and brain (.uk, 2016).Iodine was selected because it is relatively stable, and on its k-shell electron the binding edge is 32keV.this is quite similar to the normal energy of x-rays (Carver and Carver, 2012). The atomic number of iodine is 53 and 127 is the mass number which means it is considered as a heavy metal and is able to absorb radiation more effectively than soft tissues or blood (Chen, Rogalski and Anker, 2018). This allows iodinated contrast agent-containing organs or blood vessels to stand out by being white or even lighter than the underlying tissues (Bae, 2010). The dosage of iodine is an important factor of adequate opacification. An example of this is for patients who are larger it would be quite beneficial if an ICA with a higher concentration was used (Pasternak and Williamson, 2012). Furthermore, a higher concentration is needed so that the aorta can be examined. However, a lower concentration would suffice so that the smaller arteries and veins can be examined (Scholtz and Ghoshhajra, 2017). Both ICA’s share a function group known to be a tri-iodinated benzene ring; Additionally, iodine plays an important role in x-ray attenuation (Pasternak and Williamson, 2012). The majority of ICA’s are known to be aqueous meaning that the primary solvent is water for the iodine compound (Carver and Carver, 2012). As a result, ICA’s are ideal for intravascular injections as they are able to blend well with other body fluids and blood (Widmark, 2007). According to Widmark, although some ICAs are sanctioned for a particular purpose, the majority have broader responsibilities (2007). Paefgen, Doleschel and Kiessling, propose that ICAs should be provided intra-arterially for an angiogram and intravenously for a urogram. They also suggest it be visualised by specifically being inserted into the anatomy, such as the traditional joint capsule for arthrography and the bile duct for cholangiography (2015).ICA’s come in 2 forms: non-ionic and ionic. The atomic structure influences how these ICA’s behave inside the body, especially when they approach the cardiovascular system (Singh and Daftary, 2015). As indicated by Singh and Daftary the chemical structure of an ionic ICA allows the solute to be charged until it is absorbed by it. An example of this is when dissolved in blood, it causes the blood to be electrically charged (2015). Furthermore, the ICA's structure results in more molecules per kilogramme of water, enhancing its osmolality. Non-ionic ICAs, on the other hand, have a lower osmolality due to their molecular structure, which prevents them from electrically charging a solute (Singh and Daftary, 2015). Higher osmolality ICAs alter the haemodynamic of red blood cells as well as the capillary lining and may have a negative impact on pulmonary artery stiffness, blood flow, and cardiac performance (Ibid). A lower osmolality is resulted when ICA’s within a chemical structure contain more molecules per iodine atoms and then they produce lower molecules with the right contrast (Lusic and Grinstaff, 2012). The calculation of a fluids resistance to flow is known as the viscosity and this is calculated by the size of the particles, any attractions occurring between the particles and the number of particles that are present in the solution (Paefgen, Doleschel and Kiessling, 2015). If the concentration of the iodine was higher then the more viscous the ICA’s are. Additionally, viscosity is a critical feature and is considered when determining the needle size, injection time and the flowrate (Pasternak and Williamson, 2012). In order to be administered, solutions that are high in viscosity would necessitate in injection pressures being higher (Zhang et al., 2019). Warming up ICAs can reduce their viscosity to some degree (Behzadi, Zhao, Farooq and Prince, 2018).When using ionic media, it must be kept in mind that ionisation influences toxicity (Paefgen, Doleschel and Kiessling, 2015). Moreover, due to the central nervous system being vulnerable, and in the blood the ion levels were to increase this may interact with electrical activity within the body. This could potentially lead to seizures and cardiac dysfunction (Ibid). According to Paefgen, Doleschel and Kiessling, some of the common side effects of ionic media include light-headedness, a sense of warmth spreading around the body and vomiting (2015). Histamine induced in light of an ICA infusion triggers an anaphylactic or allergic reaction, however this may not necessarily attribute towards the antigens present in the blood although this is the main issue in the number of other reactions. According to Paefgen, Doleschel and Kiessling, these responses to ICAs are the outcome of a central nervous system response (2015).ICA’s delivered intravenously are circulated around in the blood before the kidneys are able to excrete. Any ICA’s that were inserted in other organs/structures will eventually get absorbed into the blood and will also be excreted by the kidneys (Paefgen, Doleschel and Kiessling, 2015). A patient who experiences renal problems may have trouble discharging ICA’s, which may result towards a bad reaction that is also called contrast-induced nephropathy (CIN) (Mohammed et al., 2013). This is a significant confusion in angiographic treatments that are mainly caused by ICA’s, and it is known to be the leading cause of acute kidney injury in UK hospitals (Rear, Bell and Hausenloy, 2014). As a result, it is important that the radiographer performs the necessary tests which ensures that the blood chemistry of the patient is within reasonable limits, and also reviewing the records of patients to note down any illnesses such as diabetes or kidney disease. These problems should then be reported on before the treatment is performed (Andreucci, Solomon and Tasanarong, 2014). Before performing the procedure, it critical that the radiographer is able to assure the request is well justified, obtains informed consent from the patient and also reviews a safety questionnaire with the patient (Vom and Williams, 2017).Endoscopic retrograde cholangio-pancreatography (ERCP) is an effective medical technique used to investigate the pancreatic duct, liver, ampulla and bile duct abnormalities (M and M, 2018). Additionally, this procedure aids in the treatment and diagnosis of pancreatic cancer, gallbladder and biliary (Ibid). From its inception, ERCP has evolved from a solely diagnostic technique to a mostly therapeutic procedure (Dasari et al., 2013). According to Stacul et al, ERCP is usually and preferably better done with IV sedation or under anaesthesia. Additionally, the complications risk is low (2011). It is vital to remember that anaesthesia and sedation play an important role in ERCP procedures, due to them assisting in the reduction of pain, anxiety and agitation in patients who are undertaking ERCP procedures. It also manages to help in the compliance and responsiveness in patients (Stacul et al., 2011). This procedure involves a local anaesthetic being sprayed into the mouth and throat to numb it to avoid regurgitation or asphyxia before the treatment begins. Additionally, the patient is administered medicine intravenously to calm them down during the procedure (Motiaa et al., 2016).Endoscopy and fluoroscopy are used in the process, in which a camera attached to a long flexible tube also known as an upper endoscope. This is then directed through the upper part of the duodenum and is able to provide the doctor with a view on the inner gastrointestinal tract on the display device but magnified (M and M, 2018). According to M and M, this enables an investigation by the doctor to be carried out on the pancreatic and bile ducts for signs of infection/inflammation, it also looks out for gallstones or any tumours present. It also allows other instruments to be moved across the main duodenal papilla towards the pancreatic and biliary ducts in order to insert a stent so that it is further dilated, removal of stones and biopsies (2018). The normal contrast medium for ERCP is an iodine-based contrast agent that is water soluble and with blood it is either isotonic or hypotonic (Lawrence and Cotton, 2013). Cotton and Leung propose that they are well tolerated when delivered intravenously and improve the relaxation during intervention (2015). ERCP is performed only after imaging procedures have determined that a condition necessitating endoscopic treatment has been identified (Cotton and Leung, 2015). Although ERCP has multiple recorded advantages, many complications can occur such as diseases or even haemorrhage, even in the possession of experts (Szary and Al-Kawas, 2013). Acute pancreatitis is a more common complication that occurs in around 12% of anonymised samples of patients and as high as 42% in patients with a higher risk (Thaker, Mosko and Berzin, 2014). A chronic condition many individuals experience is post -ERCP pancreatitis and are seen by severe stomach pains which causes them to be rushed to a hospital for care (Cotton and Leung, 2015). It is advocated by cotton and Leung to avoid this condition; the treatment should be avoided altogether and argue it should still be considered when complications are high (2015).Conclusion In conclusion the advantages of utilizing ICA’s in clinical imaging are multiple and critical. However, they can help save individuals’ lives. That being said, the risks are similarly severe and in extreme cases may lead to death. As a result, the utilization of ICA’s should be managed firmly and any individuals involved with procedures should be well informed and understand how to detect signs of danger. They should also be well equipped to know how to handle the procedure if it was to go wrong. Furthermore, appropriate medical screening will help aid in sufficient preventative steps, which will help reduce the risk of any adverse reactions. As a result, previous research has produced useful information that has aided in the appropriate and productive use of ICAs. Furthermore, this has aided in the reduction of complications, and the rate of hazards related to ICA’s tends to decrease as a result of this useful knowledge.References Andreucci, M., Solomon, R. and Tasanarong, A., 2014.?Side Effects of Radiographic Contrast Media: Pathogenesis, Risk Factors, and Prevention. [online] core. Available at: <; [Accessed 10 April 2021].Bae, K., 2010.?Bae, K.T. 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