Evaluating Complications and Applications in Newell Hospital

Introduction

Ultrasound screening and examination of the conditions of the blood vessels and arteries is crucial in detecting the various complications associated with inhibition of the performance of the blood vessel and the flow blood throughout the body vessels. Two commonly used ultrasound devices have equally been evaluate various complications affecting the flow of blood. This study examines how ultrasound works, the potential benefits and weaknesses associated with the ultrasound operations. The Newell hospital is equipped with ultrasound equipment used in a wide application of the sonography functions as will be discussed in this paper.

Role of the vascular lab

Vascular laboratory is a crucial tool in the examination and diagnosis of various vascular-related conditions. The use of the machines allows for precise images on the internal arteries and veins to examine the affected area and helps to understand the magnitude of the condition. Integrated in the hospital and part of the diagnostic process, a vascular lab specializes in a variety of tasks that help in the understanding of the vascular conditions that patients may be grappling with (Chou et al 2019). To begin with, the vascular lab provides diagnostic scanning of the conditions of the patients. Different machines adopts different orientations in the scanning and the image as well as performance qualities vary from one equipment to the other, however, diagnostic scanning adopts two main approaches. Arterial scanning is a type of diagnostic scanning that is focused on various diseases affecting the arteries including the artery disease and aneurism (Chou et al 2019). On the other hand, venous diagnostic scanning is focused on the veins of the affected areas and diagnoses venous conditions such as varicose veins, and chronic venous insufficiency (Chou et al 2019).

The tests performed at the vascular laboratory are either direct or indirect. Direct testing also known as duplex imaging involves procedures such as carotid duplex, lower extremity duplex, venous duplex, AAA stent graft assessment and renal parenchyma. Indirect testing involves procedures such as arterial ankle brachial index, arterial segmental pressures as well as arterial TOS assessment (AGNIR 2010). At the Ninewells hospital, the services offered by the vascular laboratory of the hospital include diagnostic scanning, both arterial and vascular, surveillance such as post-procedural assessments and intra-operative scanning. This laboratory also prides itself as a one-stop clinic since it also incorporates services such as triaging services, research and training.

Use of ultrasound in the laboratory

Vascular ultrasound is an integral part of the diagnosis and testing performed at the vascular laboratory. At the core of the vascular examination as well as the machine performance is the use of ultrasound. A vascular ultrasound is a non-invasive ultrasound method that is integrated in the vascular examination equipment and aids in the examination of the circulation in the blood vessels of the body (Shan 2015). In this regard, vascular ultrasound examines the human body parts by using the sound waves to evaluate the body's circulatory system and helps u]to unearth blockages in the arteries and veins and detect blood clots. This is mainly achieved using the Doppler ultrasound study which examines the blood flow through a blood vessel. Ultrasound does not use ionizing radiation and is therefore considered a relatively user friendly examination technique with minimum effects on the patients examined using the ultrasound equipment (Wells and Liang 2011).

Vascular ultrasound can be used to evaluate arteries or veins in nearly any part of the body, including your blood vessels in the neck, abdomen, arms and legs (Shan 2015). Non- invasive means the procedure doesn’t require the use of needles or anaesthesia. Unlike other imaging tests, ultrasound does not require radiation or contrast dye.

During a vascular ultrasound study, sound waves are transmitted through the tissues of the area being examined. These sound waves reflect off of blood cells moving within the blood vessels, and return to the ultrasound machine (Jensen 2007). The sound waves are recorded and displayed on a computer screen to make an image of the blood vessel. The speed of the sound waves returning to the ultrasound machine allow for calculation of the speed of blood flow in the vessel (Wells and Liang 2011). When the speed of blood flow in a blood vessel is too fast, this indicates a narrowing (blocked)

How the equipment works

Ultrasound vascular examination machine plays a significant role in the diagnostic screening of the patients in the identification of arterial and vascular infections that may be difficult to detect by use of the naked eye (Chou et al 2019). Ultrasound is characterized by sound waves which are transmitted through the equipment during the examination of the body parts suspected to be affected. The sound waves that make up the ultrasound are classified to be greater than 20,000Hz which is integrated with the frequency of 2-20 MHz to produce ultrasound images of the examined parts (Hoskins et al 2010). Being a non-invasive procedure, the patient experiences no pain associated with incisions during the examination.

During the examination, ultrasound is generated following the piezoelectric effect. Piezoelectric effect is based on the principle of converting energy through the application of pressure on the crystal (Wells and Liang 2011). In this case, elements mechanically vibrate following the application of the voltage and thus creating a sound wave into the body. The application of the varying voltages results in the amplification of frequencies concomitant to the voltage applied and results in the variations in the images produced. Following the application of the energy, a reversal procedure of withdrawing the voltage returns the energy back to the original form.

Piezoelectric effect results in two main manifestations of the ultrasound during its application in the diagnostic screening. These manifestations are echo and pulse. The pulse-echo principle underlying the ultrasound performance results in the conversion of the electricity into sound (pulse) and the conversion of sound into electricity (Echo) (Hoskins et al 2010). Thus, the ultrasound operates in the pulse-echo balance to enhance its performance.

Ultrasound is manifested in two main types as; continuous wave and pulse wave. In the continuous wave, ultrasound is characterized by the transmission and reception of the ultrasound along a particular path (AGNIR 2010). On the other hand, pulsed wave is characterized by pulse in the transmission of the ultrasound and allows for detection of the distance of the reflected structure when the time between the transmission of the pulse and the reception of the echo can be identified (Shan 2015).

The interaction of the beam with the tissues determines the images generated by the ultrasound examination. During the ultrasound examination, the beams cast from the machines react with the interface surface which is the human skin (Jensen 2007). During this interaction, some of the beam is transmitted while some is reflected and the magnitude of the reflected beam is dependent upon the acoustic impedance, also known as the result of the compatibility and density and the greater the impedance, the greater the proportion of the reflected beam (Jensen 2007).

Imaging is another aspect that determines the operation of the ultrasound. The ultrasound picture is generated as B mode, colour Doppler or spectral display. The B mode images are characterized by the varying amplitude of the returning signal. This 2 dimensional ultrasound image is composed of the bright dots representing the ultrasound echoes.

The Doppler image is based on the Doppler Effect in the measuring and visualizing the blood flow. Three types of Doppler images are the colour Doppler, continuous wave Doppler and pulsed wave Doppler (Deane 2015). In the colour Doppler image, the velocity information is presented in the form of colour-coded overlay on top of the B-mode image. The continuous wave Doppler image is generated when the Doppler information is sampled along a line through the body (Deane 2015). During this sampling, the velocities detected at each point of sampling are presented. In the pulsed wave Doppler image, the Doppler information is captured only from a small sample volume and presented on the timeline.

The limitation of equipment

Ultrasound equipment use has accompanying limitations that hamper effective functioning. These limitations are drawn from the capacity and performance of the machine to external aspects such as expertise needed to operate the machine. There are a number of limitations associated with ultrasound equipment. To begin with, ultrasound devices have difficulties when used in examining the vessels that are in the interior part of the bone or concealed with the bone structure since the machine has limited capacity of penetrating the bone (Fan and Sekins 2015). This limits the application of the ultrasound machines in the examination of blood vessels in the human brain due to the skull’s obstruction. Secondly, ultrasound machines performance is limited in the presence of gas between the transducer and the organ of interest, due to the extreme differences in acoustic impedance (Abou-Elkacem et al 2015). For instance, the ultrasound screening for the pancreas is limited due to the presence of the gas in the gastrointestinal tract. However, the lungs can be imaged using the ultrasound and will be useful in detecting heart failures and pneumonia, as well as demarcating pleural effusions. Third, the ultrasound imaging is dependent on the frequency of imaging. Therefore, low frequencies may

be limiting to the machine’s ability to penetrate through the body vessels and get clear images of the affected blood arteries and veins and this may be particularly difficult in those structured deep in the body as in obese patients (Hoskins et al 2010). This also points to the fact that physique of the body imaged determines the effectiveness of the ultrasound machines in the screening of the body vessels and arteries. Thus, the accuracy of diagnosis is limited in blood vessels covered by overlying subcutaneous fat which attenuates the sound of the beam. The other weakness associated with the ultrasound equipment is the fact that the ultrasound method is operator-dependent. To produce good-quality images of the structure under examination, a high level of skill, expertise and experience is required. This is equally the case for examining the hard- to view structures such as the brain and the areas covered by subcutaneous fat.

Ultrasound examinations require being in a static position of the machines in order to get good quality images. Therefore, the user should ensure that the machine is kept in the same position throughout the ultrasound probe (Shan 2015). However, users performing the ultrasound screening might have challenges with keeping the ultrasound probe on the same position during an examination and this may impact the quality of the image produced. The other weakness of the ultrasound examination machine is the difficulty to detect the area of the body that was imaged. With the ultrasound machine, there is no scout image as there is with CT and MRI and once an image has been acquired there is no exact way to tell which part of the body was imaged (Hoskins et al 2010). With the continued use of the ultrasound machines, sonographers may suffer from Work-Related Musculoskeletal Disorders (WMSD) or the Repetitive Strain Injuries (RSI) because of the bad ergonomic positions during the examination exercises (Fan and Sekins 2015).

Benefits of ultrasound equipment

The ultrasound equipment is applied in a variety of body imaging examinations based on the benefits associated with the equipment. First, the machine is useful and helps to monitor the flow of blood to the organs and tissues throughout the body. The blood is crucial in the body functioning and proper blood circulates benefits the body by maintaining the optimal performance of the body organs and tissues as well as supplying vital nutrients throughout the body (Fan and Sekins 2015). During the examination of the blood vessels and the blood flow throughout the body, ultrasound equipment can be used to locate and identify blockages (stenosis) and abnormalities like plaque or emboli that may be present in the body. This allows the health practitioners to plan and deliver effective treatment to the conditions.

The ultrasound machines are also crucial and can help to detect blood clots such as deep venous thrombosis in the major veins of the legs or arms and these too can receive treatment accordingly. Blood clots such as deep vein thrombosis inhibit the flow of the blood throughout the body parts thus inhibiting the functioning of organs and the tissues as well as the heart and may result in conditions such as cardiac arrest. This emphasizes the vital role played by the ultrasound equipment by detecting the blood clots.

Ultrasound screening is useful in determining the procedures for restoring the health of the patients (Shan 2015). Procedures such as angioplasty, graft or bypass of the blood vessels greatly benefit from ultrasound examinations. Angioplasty for instance is a procedure for fixing the blood vessels of the patients and thus ultrasound screening helps in preserving the health of the patients. Other aspects that benefit from ultrasound includes examination of aneurysm, and evaluating the varicose veins.

Ultrasound can also be used in children patients and has been identified to aid in the placement of a needle or catheter into a vein or artery to mitigate complications such as bleeding and nerve injury (Imbault et Al 2017). Additionally, conditions such as pseudo-aneurysm are likely to occur among children and thus ultrasound equipment can help to detect such conditions for early mitigating to avoid the rupturing of the out pouched artery.

Ultrasound screening is also beneficial in evaluating a connection between an artery and a vein which is crucial in the cases of congenital vascular malformations. With the identification of the connection between arteries and veins, the ultrasound screening can then help in the diagnosis of fistula cases.

The arms and legs are often characterized by the presence of small blood vessels and due to the nature of these blood vessels, blood clotting is highly likely to be formed thus inhibiting the complete flow of blood through the legs and arms. This impedes the functioning of the affected body parts. Children are at higher risk of being affected by the blood clotting in the arms and legs due to the small vessels in their arms and legs. The formation of plaque is not frequent in children though the occurrences of compression at the inlet of the chests are also likely. In this case. Ultrasound screening through Doppler and duplex Doppler devices can be quite useful in determining the presence of blood clot in the veins of the arms and legs as well as cases of compression of the chest (Aaslid et al 2019).

Safety considerations

Debates around the safety of ultrasound devices have prompted studies that have sought to examine the availability and extent of the safety effects of the equipment. For instance, studies by Wells and Liang (2011) identified no statistically noteworthy detrimental effects from the equipment, but stated that unavailability of data hampered the estimation of the long term effects of the ultrasound equipment on aspects such as neurodevelopment. Imbault et al (2017) established a link between the long term use of the ultrasound equipment and safety health effects such as abnormal neuronal migration in mice. It becomes questionable however, whether these results can be applicable to human beings. Furthermore, Fan and Sekins (2015) identified that elusive effects of the neurological damage were associated with the ultrasound screening.

Therefore, while there is no substantial data from the above three studies comparatively on the safety concerns associated with the exposure to ultrasound machines, it is crucial to adhere to safety and precautionary measures when handling and using ultrasound equipment.

Management of the equipment

Effective management of the ultrasound equipment can be achieved through a number of measures. It should be emphasized that just like other equipment using electricity, adherence to all procedures of safe use of electrical equipment such as consideration of voltage, avoiding overloading sockets, switching off the equipment when not in use are the premier management initiatives that will enhance long term performance of the equipment.

Secondly, the use of ultrasound machines is specified in the manufacturer’s manual on the optimal performance of the equipment. One of such recommendations is keeping the machine still during the imaging process. Adherence to this and other recommended measures will help in effectively manage the optimal operation of the equipment.

Third, there are professional guidelines with the use of ultrasound screening equipment. For instance, the ultrasound equipment in the vascular lab are designed and should only be operated by trained and skilled practitioners among other set operational procedures are meant to enhance the optimal functioning and durability of the ultrasound equipment.

An examination of two used equipment at Ninewells hospital

Doppler ultrasound

A Doppler ultrasound equipment is used in conducting a non-invasive test which is aimed at depicting the flow of blood by bouncing high-frequency sound waves off the red blood cells to create images of blood vessels, tissues, and organs (Aaslid et al 2019). During this examination the obstruction of the blood flow is indicated by the faintness or the absence of the sound. When the equipment is in operation, the size of the blood vessel’s opening is dependent on the amount of blood pumped with each beat. Additionally, the Doppler ultrasound has the potential of detecting the abnormal flow of blood within the vessel and helps to identify indications of blockage caused by plaque, blood clot and inflammation (Aaslid et al 2019). The equipment can also be useful in the identification pf tumours and congenital vascular malformations and increased blood flow that may be an indication of an infection.

Duplex Doppler device

Duplex ultrasound device is an equipment that involves using high frequency sound waves to examine the speed of blood flow and the structure of the leg veins. Duplex Doppler is premises on the fact that the equipment relies on two modes of ultrasound which are, Doppler and B-mode in its operations (Deane 2015). Ideally, the machine relies on the B-mode to obtain the image of the blood vessel being examined while the Doppler probe in the transducer allows for the evaluation of the velocity and the direction of the flow of blood within the same blood vessel examined (Deane 2015). There are several operations that can be evaluated based on the duplex dropper. For instance, duplex Doppler examination involving a carotid duplex scan may be conducted to evaluate the obstruction or stenosis of the carotid arteries of the neck of the branches of the carotid artery of the heart. The duplex 2-dimensional image produced by the duplex Doppler equipment is crucial in understanding the structure of the arteries and the location of the occlusion and the blood flow degree.

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References

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Fan, L. and Sekins, K., Siemens Medical Solutions USA Inc, 2015. Feedback in medical ultrasound imaging for high intensity focused ultrasound. U.S. Patent 8,992,426

Shung, K.K., 2015. Diagnostic ultrasound: Imaging and blood flow measurements. CRC press. Abou-Elkacem, L., Bachawal, S.V. and Willmann, J.K., 2015. Ultrasound molecular imaging: Moving toward clinical translation. European journal of radiology, 84(9), pp.1685-1693.

Imbault, M., Chauvet, D., Gennisson, J.L., Capelle, L. and Tanter, M., 2017. Intraoperative functional ultrasound imaging of human brain activity. Scientific reports, 7(1), p.7304.

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Chou, D., Go, M.R., Starr, J.E. and Satiani, B., 2019. A Roadmap for Noninvasive Vascular Laboratory Education. Journal for Vascular Ultrasound, p.1544316719886759.