Example Of Pulmonary Embolism Essay

Pulmonary embolism

Pulmonary embolism is a life threatening condition that occurs when a mobile thrombus occludes the pulmonary artery or a branch of the pulmonary artery. The origin could be air, fat, amniotic fluid, bacterial invasion or a migrated deep venous thrombus (Tapson, 2008). There are several primary methods of diagnosing pulmonary embolism though not all of them are feasible, cost effective or even available depending on the clinical setting of the patient. Timely and correct diagnosis can mean the difference between saving a life and losing it.

Current Primary means of Diagnosing Pulmonary Embolism

History taking is the first step in diagnosing a case of pulmonary embolism. It needs to capture any incidences that are considered high risk for the condition such as trauma, surgery, pregnancy, heart failure, prolonged immobility or any condition that predisposes to hypercoagulable states. The conditions presentation needs to be elicited and this include tachypnea, rales, tachycardia and cyanosis. Other conditions that present with similar symptoms need to be excluded. A properly done history is going to provide a high index of suspicion that will ensure more sensitive diagnostic measures are taken (Doyle, Ramirez, Mastrobattista, Monga, Wagner & Gardner, 2004).
Together with history a physical exam is done. The area of focus during this physical exam will be to rule out deep venous thrombosis that may be a precursor to pulmonary embolism. Auscultation of the heart and lungs is done during the physical examination. The patients’ blood pressure and saturation of oxygen done through pulmonary oximetry are also important supportive tests (Doyle et al., 2004).
Another diagnostic approach is by use of chest X-ray. Even though it is not confirmatory for pulmonary embolism the test is important because it helps to rule out other conditions with similar presentation given that there is little room for misdiagnosis. The X-ray may be normal or may demonstrate infiltrates. X-ray cannot be used as a stand-alone test. In an acute care setting the ECG can come in handy during assessment. Patient with pulmonary embolism usually demonstrates characteristic changes to their QRST complex. To begin with the patient usually presents with increased heart rate. Secondly this patient also demonstrates the depression of PR interval. The patient may also have changes on his T wave though these changes are unspecific. ECG may be used to rule out myocardial infarction (Doyle et al., 2004).
Arterial blood gas analysis is also one of the primary diagnostic tools for the condition. A sudden drop in the partial pressure of oxygen in blood results from the blockage of the pulmonary artery by the emboli. The patient may also present with low partial pressure of oxygen as a result of tachypnea. The patient washes out his carbon dioxide through hyperventilation. However 1 in 5 patients with pulmonary embolism will show no changes in their arterial blood gas analysis. This makes it a poor tool for confirmatory diagnosis but useful one as a supportive tool (Doyle et al., 2004).

New Diagnostic Technique used to diagnose pulmonary embolism

There has been new development in the effort to diagnose pulmonary embolism. This has led to development of new and definitive diagnostic technique. One of such new and definitive diagnostic test for pulmonary embolism is pulmonary angiography. Pulmonary artery can be visualized by X-ray post injection of a contrast media into the artery. In this test a catheter is passed into the pulmonary artery via femoral and through it a contrast agent is injected into the artery. Any occlusions to or defects the flow of blood within the artery can be visualized when an x-ray is taken. The contrast media will not permeate to the occluded areas. Despite its specificity this method may be expensive and cannot be easily performed on critically ill patients and require the expertise of special teams who might not be readily available when needed (Clemens & Leeper, 2007).
Magnetic resonance imaging is also one of the new techniques being used in diagnosis of pulmonary embolism especially in pregnant women or in people who are sensitive to the contrast agent. It provides a better image of the internal structures of organs than the normal X-ray film without the exposure to radiation. Through this areas of occlusion can be clearly seen even though this is an expensive option. The catheter may in turn be used to deliver clot dissolving medication or manual for manual removal of the clot (Clemens & Leeper, 2007).
A ventilation-perfusion scan can also be used. The perfusion scan will show areas with reduced blood flow or total obstruction of blood flow depending on the extent of occlusion. On the other hand the ventilation scan will indicate whether a ventilation abnormality is present. It’s used especially in instances in which the CT scan is not available or is contraindicated. A lab analysis for a hypercoagulable state can be done if no obvious cause for pulmonary embolism is present. The patient is analyzed for; antithrombin deficiency, homocystinuria, other connective tissue disorders or an occult neoplasm. This is helpful especially in management of the condition (Clemens & Leeper, 2007).
We have also another new approach to diagnosis of pulmonary embolism which is the use of a spiral computed tomography as opposed to the traditional Computed tomography. This method eliminates gaps between images. The outcome is a more accurate image of the pulmonary emboli. A contrast agent administered intravenously is necessary before visualization can take place. A lab test can be done to confirm the presence of clots. The D-dimer test is a measurement a clot break down product. Elevated levels of D-dimer point to a pulmonary embolism diagnosis (Clemens & Leeper, 2007).
Doppler ultrasound is used to diagnose deep venous thrombosis. It will demonstrate clots in the deep veins in the calf muscles by use of sound waves. Thrombi may migrate from this area to cause pulmonary embolism. The down side to this test is that by the time the test is carried out the thrombi could have completely migrated to the lungs and thus a negative test does not rule pulmonary embolism that is caused by deep venous thrombosis (Clemens & Leeper, 2007).

My preferred Diagnostic Technique

My preferred diagnostic test for pulmonary embolism is pulmonary angiography. It is an approach that can be used both for diagnosis and carrying out an intervention. The method allows for direct observation of the occluded area with the aid of fluoroscopy. It can also help in the assessment of perfusion deficit. The catheter may also be used either as a delivery channel for medications that will dissolve the clot or to manual remove the occlusion. This will ensure prompt intervention once the diagnosis has been made. It is this duality of use for both diagnosis and intervention that gives it an upper hand.
Another evidence for the above choice is that outcomes from diagnoses made through pulmonary angiography were half as lethal when compared to those done through ventilation perfusion scan. Pulmonary angiography was able to capture more of the non-lethal pulmonary embolism than ventilation-perfusion scan. This proves that the test more specific and less likely to miss a case of pulmonary embolism no matter the severity of the condition (Sheh, Bellin, Freeman, & Haramati, 2012).

References

Clemens, S., & Leeper, K. V. (2007). Newer Modalities for Detection of Pulmonary Emboli. American Journal of Medicine, 120. doi:10.1016/j.amjmed.2007.07.014
Doyle, N. M., Ramirez, M. M., Mastrobattista, J. M., Monga, M., Wagner, L. K., & Gardner, M. O. (2004). Diagnosis of pulmonary embolism: A cost-effectiveness analysis. In American Journal of Obstetrics and Gynecology (Vol. 191, pp. 1019–1023). doi:10.1016/j.ajog.2004.06.048
Sheh, S. H., Bellin, E., Freeman, K. D., & Haramati, L. B. (2012). Pulmonary embolism diagnosis and mortality with pulmonary CT angiography versus ventilation-perfusion scintigraphy: Evidence of overdiagnosis with CT? American Journal of Roentgenology, 198, 1340–1345. doi:10.2214/AJR.11.6426
Tapson, V. (2008). Acute pulmonary embolism. New England Journal of Medicine, 358, 1037–1052. doi:10.1056/NEJMra072753