Carlos A. Guanche, MD

A history of weight loss underscores the severity of the problem and a history of pneumonia indicates the occurrence of intolerable aspiration pregnancy yoga classes buy alendronate with mastercard. Meal duration may be prolonged for these patients and they may avoid certain types of food they know to worsen their symptoms (Castell & Donner women's health clinic in ottawa alendronate 70 mg on-line, 1987) breast cancer pictorial order alendronate 70 mg on-line. A sudden onset of dysphagia is more likely to occur with trauma or ingestion of a foreign body menopause weight gain on abdomen alendronate 70 mg low cost. Careful questioning of the patient may be required to elicit a history of chicken or fish in the recent diet menopause test order alendronate 70 mg online, indicating the possibility of a bone lodged in the aerodigestive tract. Past Medical History A history of heartburn, indigestion, or known gastroesophageal reflux is significant in that chronic irritation of the pharyngeal mucosa can enhance a foreign-body sensation. A long exposure of the esophageal mucosa to stomach acid may lead to poor relaxation of the upper esophageal sphincter and subsequent solid food dysphagia. Over time, failure of upper esophageal sphincter relaxation can lead to the development of pharyngeal diverticuli. Gastroesophageal reflux can also lead to aspiration of an extremely caustic nature that is not necessarily associated with swallowing (Leonard & Kendall, 1999; Shaker, 1995). A history of neuromuscular disease is important, as this may be the primary etiology of the swallowing abnormality and gives an indication of the prognosis for improvement. Past surgical procedures involving structures of the oral cavity and pharynx may be responsible for altered swallowing function. Head and neck radiation therapy can lead to fibrosis of structures whose mobility is required for adequate swallowing and will cause xerostomia (Kendall, McKenzie, & Leonard, 1998). Many medications cause decreased salivary production and contribute to poor bolus lubrication and clearing. These medications act primarily through their effects on the parasympathetic nervous system, responsible for the stimulation of salivation. Drugs may be "parasympathomimetic," meaning that they stimulate or simulate the parasympathetic nervous system. Drugs that are "parasympatholytic" block or decrease parasympathetic stimulation, causing a decrease in salivary output and a dry mouth. Antihistamines and antinausea medications commonly have anticholinergic side effects. The use of multiple drugs, a common finding in older patients, may result in drug interactions that potentiate the anticholinergic effects of those drugs. Drugs that increase brain dopamine levels by stimulating the release of dopamine may cause a dry mouth. Antipsychotic medications that act by blocking dopamine receptors also cause a dry mouth. Some patients taking this type of medication experience dry mouth, as these drugs produce a significant reduction in salivary flow. Newer antidepressants that block serotonin reuptake are also known to cause dry mouth. Dry mouth is a side effect of many of these compounds (Hunter & Wilson, 1995; Vogel & Carter, 1995). In the case of diabetes, oral dryness is not associated with a malfunction of the parasympathetic nervous system but appears to be due to disturbances in glycemic control (Sreebny, Yu, Green, & Valdini, 1992). A bright light source is required to illuminate the oral cavity, pharynx, and hypopharynx. The patient should be seated at a level 30 Dysphagia assessment anD treatment planning: a team approach so that he or she is slightly higher than the examiner. The legs should be uncrossed and the patient should be sitting up straight, leaning slightly forward at the hip. The face of the patient should be examined for any obvious asymmetries or outward signs of trauma. Abnormalities of cranial nerve function and facial sensation may be clues to the diagnosis of central or neuromuscular disease. A nasal exam should rule out any masses that could impinge upon the hard palate or the soft palate and therefore preclude complete closure of the velum. Effective swallowing requires that the alimentary tract structures move in order to generate pressure to propel the bolus from the oral cavity to the stomach. To accomplish pressure generation, the structures of the oral cavity and pharynx act like a series of chambers that expand to accept the bolus and then contract to expel the bolus. The valves close in front of the bolus and prevent premature movement or spillage of the bolus as well as escape of pressure ahead of the bolus. The valves close behind the bolus and allow the development of pressures that will effectively and efficiently move the bolus into the next chamber. The valves of the upper aerodigestive tract include the lips, the soft palate, the vocal folds, and the upper esophageal sphincter. The head and neck physical examination in a patient with dysphagia must focus on the competency of the valves and the ability of the chambers to effectively expand and contract, resulting in bolus movement. Examination of the alimentary tract should begin with the lips, the first valve in the swallowing mechanism. Lip inspection should include an evaluation of sensation and, especially, competency. Oral competence, or complete closure, is required to generate pressures used to move the bolus from the oral cavity into the oropharynx, and any evidence of oral incompetence indicates the patient likely has difficulty with the oropharyngeal transition of bolus material. Two tongue blades aid in the examination of the oral cavity, the first chamber of the swallowing mechanism. The patient is asked to open the mouth, and the tongue blades are employed to move structures allowing complete inspection of all the mucosal surfaces. Trismus can be a sign of temporomandibular joint disease or pterygoid muscle abnormalities. Carious, broken, and missing teeth may also lead to difficulty with bolus preparation. The mucosal surfaces should be inspected for irregularities, lesions, and moisture. Lack of saliva will preclude adequate bolus lubrication, making dry foods especially difficult to swallow. During bolus preparation, the base of the tongue contacts the soft palate and prevents premature movement of the bolus from the oral cavity into the pharynx, acting as the second valve in the swallowing system. The tongue base/soft palate valve posteriorly and the closed lips anteriorly contain the bolus in the oral cavity for bolus preparation. Once the bolus is adequately masticated and lubricated for swallowing, the anterior tongue contacts the hard palate sequentially from front to back, moving the bolus into the pharynx as the soft palate elevates and the tongue base depresses. The tongue examination also includes a notation of any surface irregularities, fasciculations, or atrophy. The patient should be asked to protrude the tongue and to move it from side to side in order to judge mobility. Tongue strength can be further tested by asking the patient to push with the tongue on a tongue blade. Palpation of the tongue allows detection of any masses that are not evident on visual inspection alone. Although tongue mobility is critical for effective contraction of the oral cavity "chamber" resulting in bolus move- ment, the cheeks, floor of mouth, and hard palate also participate in maintaining adequate pressures during contraction of the oral cavity "chamber. Any defect of the hard palate will allow pressure and bolus material to escape into the nasal cavity. The lingual sulci should be examined to rule out tethering of the tongue to the inner surface of the mandible. Examination of the oropharynx also should begin with a visual inspection of the mucosal surfaces to rule out any obvious abnormalities such as masses or ulceration. The soft palate should elevate symmetrically when the patient is asked to say "ah. Perhaps more importantly, the soft palate also works as a valve during the pharyngeal phase of swallowing by closing off the nasopharynx through contact with the posterior and lateral nasopharyngeal walls (velopharyngeal valve). Weakness or defects of the soft palate allow pressure and bolus material to escape into the nasopharynx rather than being directed into the hypopharynx during the pharyngeal phase of swallowing. These techniques enable the visual inspection 32 Dysphagia assessment anD treatment planning: a team approach of the tongue base as well as the larynx and region of the upper esophageal inlet. Indirect laryngoscopy is no longer routinely performed because it can be technically challenging and uncomfortable for the patient. The indirect laryngeal examination also is limited in that the evaluation of the nasopharynx and hypopharyngeal sensation cannot be performed adequately. On the other hand, flexible laryngoscopes provide excellent optics, are more comfortable for patients, allow recording of the exam for playback and review with patient education, include examination of the nasopharynx, and can be used to test hypopharyngeal sensation. In order to perform indirect laryngoscopy, the patient must be positioned to carry out the examination in such a manner as to provide the best visualization with the least discomfort. The patient should be asked to extend the neck anteriorly so that the mandible is forward. The examiner holds the tongue with a thin gauze sponge and stabilizes the position of the patient with the same hand. A warmed mirror is introduced into the oral pharynx with the other hand, using care not to touch the tongue base with the mirror. As we have previously mentioned, the tongue base is extremely sensitive and a region involved in the swallowing reflex initiation. The soft palate, however, is not as sensitive and the mirror can be placed against it as it is positioned posteriorly in the oral pharynx for viewing of the hypopharynx. The mirror can be pivoted back and forth to allow full examination of the hypopharyngeal structures. In order to perform flexible laryngoscopy with minimal discomfort to the patient, the nostrils can be sprayed with topical phenylephrine (Neo-Synephrine, 1/4%) and/or topical anesthetic such as lidocaine (4%). Patient positioning is similar to that for indirect laryngoscopy with the patient sitting up straight with slight anterior flexion at the hips and chin protruding forward. Palatal mobility is evaluated along with velopharyngeal closure (valve of the soft palate against the nasopharyngeal walls) by asking the patient to perform a forceful "sss" sound. Leakage of air and secretions during the "sss" sound indicates incompetence of the velopharyngeal valve. Once the nasopharyngeal portion of the examination is complete, the patient is asked to breathe through his nose and thus open the nasopharyngeal passage by relaxing the soft palate for further advancement of the flexible scope and evaluation of oro- and hypopharyngeal structures. During the initial part of pharyngeal swallowing, the tongue base depresses and the hyoid and larynx move anteriorly, effectively expanding the pharyngeal chamber to 2. This structural displacement of the tongue base and larynx also protects the airway. Meanwhile, at the top of the pharyngeal "chamber," the soft palate acts as a valve with the nasopharynx, preventing bolus and pressure escape into the nose. At the bottom of the chamber, the upper esophageal sphincter and the vocal folds act as valves, closing off the airway and the esophagus respectively. The "chamber" of the pharynx constricts by sequential contraction of the tongue base against the contraction of the pharyngeal constrictor muscles. Opening of the upper esophageal sphincter along with contraction of the pharyngeal chamber propels the bolus into the esophagus. Physical examination of the pharynx starts with evaluation of the base of the tongue, the vallecula, and the epiglottis. The presence or absence of saliva pooling in the vallecula, piriform fossae, or glottic opening suggests significant dysfunction of the swallowing mechanism and identifies patients with significant risk for aspiration. The piriform fossae are also evaluated in terms of asymmetries, mucosal lesions, or masses. The patient is asked to say "ee," which closes the vocal folds and further elevates the larynx for inspection. The patient may be asked to perform a rapid "ee-ee-ee" sequence to assess fine control of vocal fold movement and closure. The vocal folds should be evaluated during inspiration as well, to allow visualization of the vocal fold medial surfaces that are obscured during phonation. The interarytenoid region should be evaluated for color and character of tissues, as erythema of this region may indicate irritation. Once hypopharyngeal inspection has been carried out, a test of sensation in the pharynx can be performed. By touching the tongue base and posterior pharyngeal wall with the tip of the flexible scope, a gag reflex should be elicited. The tip of the flexible scope is also used to touch the piriform fossae, lateral pharyngeal walls, aryepiglottic folds, laryngeal surface of the epiglottis, and the vocal folds themselves. Abnormal sensation can contribute significantly to difficulties with initiating a swallow and control of the bolus. The final part of the physical examination involves palpation of the neck for anatomic abnormalities, especially masses. Adenopathy may be indicative of metastasis from an upper aerodigestive tract mucosal malignancy or a lymphoma. Malignancies tend to be firm and fixed to surrounding structures, while reactive adenopathy has a more rubbery character and is usually mobile. Palpation of the laryngeal cartilages confirms normal laryngeal structural integrity, and gentle displacement of the larynx side to side confirms a lack of tethering. The following is a list reviewing the information that may be gained during the physical examination. What important information is learned from the past medical history with respect to complaints of dysphagia Describe the limitations of the physical examination and what testing can be done to complement the physical examination. Yet, these sensory deficits may be responsible for delayed swallow reflex triggering and poor bolus control. The same problems exist in the evaluation of subtle motor deficits that may not be detected on the physical examination. The complex coordination of swallowing may be abnormal in patients with central control deficits who present with normal anatomy, sensation, and apparent muscular function.

Of particular concern in examination of the pharynx and upper esophagus is radiation exposure to the thyroid womens health 33511 buy alendronate 70 mg with mastercard. Radiation exposure of the lens of the eye is also an important issue when the head and neck are exposed to radiation menstruation 1700s buy alendronate with a mastercard. A comparison of radiation exposure for the techniques used for radiographic swallowing studies is seen in Table 5­1 women's health clinic elko nv buy alendronate with mastercard. Most modern fluoroscopic machines incorporate safety features to minimize radiation such as beam coning women's health new zealand discount alendronate 35 mg amex, last frame hold menstrual uterine lining cheap alendronate 35 mg buy, automatic kVp adjustment, grid removal, and adjustable frame rates. Operators should employ appropriate shielding, reduce screening time to the minimum needed to achieve the required information, and avoid backscatter by removing objects within the beam path. The patient should always be positioned closest to the detector, and staff should stand a minimum of 5 feet from the beam emitter whenever possible. During a normal year, we are exposed to approximately 3 mSv of background radiation. Most fluoroscopic swallowing studies are estimated to deliver doses in the range of 0. Despite care being needed to optimize fluoroscopic swallows, it is imperative to get all the information needed from the study. Therefore, reducing frame rates to minimize radiation dose may not be helpful given that important swallow information may be lost or go undetected. There must be a balance between an effective study and minimizing long-term radiation risk. There is far greater risk to health in missing aspiration or swallow impairment in this age-group, and the clinician should be aware of all factors involved. Indications History and clinical examination provide invaluable information in assessing the dysphagic patient; however, they are unable to detect silent aspiration, one of the leading causes of disability and death in patients with neurological conditions, head and neck cancer, or head and neck trauma or following surgery (Garon, Sierzant, & Ormiston, 2009; Ramsey, Smithard, & Kalra, 2003, 2005). An instrumental examination is required to fully assess the pharyngeal and esophageal phases of swallowing. This examination is indicated in patients presenting with persistent dysphagia, odynophagia, aspiration, pulmonary pathology, chronic cough, regurgitation, weight loss, or, in some cases, symptoms of reflux or esophageal pathology (chest pain or pressure), or in patients after surgery or radiotherapy to the head and neck. Because radiation exposure is involved, careful consideration must be given to performing the optimal study in the shortest possible time. Specific maneuvers or strategies can be tested during the study to enable safe treatment recommendations. Contraindications to esophageal examination with standard barium swallow and esophagram include inability of the patient to swallow, obstruction of the pharynx or esophagus, and a strong likelihood of aspiration. The patient takes a bolus of barium (about 60% weight/volume) into the mouth and is instructed to swallow while a recording is made from the oral cavity to the cervical esophagus. In the normal person, the passage of a bolus of barium from the mouth to the cervical esophagus takes approximately one second. The valleculae and piriform sinuses are usually better seen in this projection, whereas the epiglottis and cricopharyngeus muscle are less Examination Technique Because of its general availability and ability to demonstrate motion, videofluoroscopy is the method most often used for swallowing studies and other examinations of the pharynx. The examination is performed in the standing or sitting position using a standard fluoroscopy table in the upright position. Asymmetries reflecting unilateral weakness, for example, of the pharynx, are also likely to be better appreciated in the frontal view. In both projections, recordings are made while the patient swallows several different quantities and consistencies of barium, and in some cases, swallowing is evaluated with a bolus of food mixed with barium. This is termed silent aspiration and is common in patients with neurological deficits or disorders and sensory impairments (such as after radiotherapy or surgery to the head and neck). Silent aspiration can have significant clinical consequences, including pneumonia, lung abscess, and death (Garon, Sierzant, & Ormiston, 2009; Ramsey, Smithard, & Kalra, 2003, 2005). Because there is no obvious response from the patient, silent aspiration cannot be detected during clinical examination. A change in voice quality after a swallow may indicate presence of bolus material on the vocal folds, but as noted, silent aspiration may happen with no clues. These are often small (1­2 mm) and non-obstructive but can become larger, circumferential, and then narrow the esophageal inlet. This is mobile with the larynx, non­obstructive, and caused by mucosa overlying prominent muscle strips and veins beneath the pharyngoesophageal mucosa (Allen et al. Because it is possible for an abnormality in the esophagus to cause pharyngeal symptoms, in most cases this organ should be evaluated along with the pharynx (Smith, Ott, Gelfand, & Chen, 1998). As part of the esophageal screen, the patient is administered a 13-mm barium tablet to swallow, and this is again followed from oral cavity to the stomach. During the esophageal screen, particular note is made of the transit time to the stomach (normal 10 s for liquid boli, but up to 30 s for paste or solid textures), completeness of bolus transfer. The esophageal screen has a sensitivity and specificity of greater than 70% for common esophageal pathologies and may allow the clinician to direct further investigations more appropriately (Allen et al. For example, if a constriction is noted, 80 Dysphagia assessment anD treatment planning: a team approach the patient may be sent for endoscopy to delineate the nature of the mechanical obstruction, or if there is significant intraesophageal stasis or reflux, manometry may be warranted. The esophageal screen does not replace a formal esophagram but may give valuable information regarding the cause of patient symptoms and direct further appropriate investigations. Formal esophageal evaluation (esophagram/barium swallow) is generally examined by fluoroscopy and spot films, which can be obtained either by standard films or digital recording of individual frames. This examination is also done by observing a bolus of barium as it passes through the esophagus from the level of the cricopharyngeus to the stomach (Carucci & Turner, 2015; Levine & Rubesin, 2017). The examination is performed in the frontal, lateral, and oblique projections, and observations are made both in the upright and recumbent positions. The esophagus is a tubular structure that measures approximately 23 to 25 cm in length and 1 to 2 cm in diameter. The upper limit of the esophagus is at the upper esophageal sphincter at the level of the cricopharyngeus muscle and the lower border is the cardiac orifice where the esophagus joins the stomach. The anatomy of the distal esophagus is somewhat complex but important to understand when evaluating clinical problems. The increased pressure in this area can be measured by intraluminal manometry, and an area of intermittent narrowing is often seen during barium studies. In addition to evaluation of the esophageal anatomy, peristalsis is observed in the prone position. The types of peristalsis that are seen include the primary wave (initiated by swallowing), sec- ondary peristalsis (initiated by retained barium in the esophagus), and tertiary contractions (nonpropulsive contractions of the distal third of the esophagus) (Laufer, 1994; Megibow, 1994). An important part of this examination is the evaluation for possible reflux of barium from the stomach into the esophagus. Reflux of stomach contents into the esophagus is a very common condition that usually causes pain in the epigastric or substernal regions, but occasionally produces dysphagia 82 Dysphagia assessment anD treatment planning: a team approach is highly non-physiologic and no one would be likely to eat or drink in this position. Abnormalities that may be seen during the examination of the esophagus include hiatal hernia, with or without reflux; webs, rings, or strictures; benign or malignant tumors (suggested by irregular narrowing) and motility disorders of the distal esophagus including achalasia. These patients are often referred for further evaluation (including endoscopy) and treatment. What structures, and pathologies, may be better viewed from a frontal (A/P) projection than a lateral projection What is the difference between primary and secondary peristalsis in the esophagus In addition, reflux into the hypopharynx may result in aspiration, hoarseness, and cough. The examination is done in the supine position after the patient has consumed about 300 to 400 mL of barium solution. While the examiner observes the gastroesophageal junction fluoroscopically, the patient is asked to cough, do a Valsalva maneuver, and raise both legs above the x-ray table. All of these techniques increase intraabdominal pressure and thus may produce reflux. Some radiologists advocate using the "water siphon test," which consists of observation for reflux with the patient in the Trendelenburg position while drinking water. Although this test is more likely to induce reflux, the argument against its use is that it 5. Comparison of esophageal screen findings on videofluoroscopy with full esophagram. Projected cancer risks from computed tomographic scans performed in the United States in 2007. Patient dose during videofluoroscopy swallowing studies in a Hong Kong public hospital. Cine magnetic resonance imaging with single-shot fast spin echo for evaluation of dysphagia and aspiration. History and evolution of the barium swallow for evaluation of the pharynx and esophagus. Computed tomography of the gastrointestinal tract: Techniques and principles of interpretation. Esophageal visualisation as an adjunct to the videofluoroscopic study of swallowing. Videofluoroscopy and oropharyngeal manometry for evaluation of swallowing in elderly patients. Lower esophageal mucosal ring: Correlation of referred symptoms with radiologic findings using a marshmallow bolus. The use of highspeed, continuous, T2-weighted magnetic resonance sequences and saline for the evaluation of swallowing. Recording and imaging technologies have advanced significantly, with improvements both in image quality and ease of analysis. In this text, three chapters are devoted to various aspects of the fluoroscopic swallow study. When we began 85 doing studies and attempting to get as much information from them as possible, both subjectively and from objective measures of swallow mechanics, we found that our understanding of swallow function, and dysphagia, was significantly enhanced. Fluoroscopy also continues to be the tool that provides the most information about mechanical characteristics of swallowing; consequently, its use and the results that are possible with its careful analysis are emphasized here. Ideally, all will have undergone evaluation, at least by their primary physician, and perhaps treatment for underlying diseases, most frequently directed by a gastroenterologist, neurologist, or otolaryngologist. In our practice, which includes both outpatients and inpatients, the dysphagia may be acute or chronic, obvious or subtle, severe or mild. In our facility, fluoroscopy time is generally limited to <3 minutes, and rarely exceeds 4 minutes. Prior review of patient history, and a thorough clinical evaluation, will optimize time spent in the fluoro suite. Frequency of repetition of the study should also be carefully considered due to the risks of radiation exposure. Another limitation of fluoroscopy is its dependence on the quality of images obtained. If critical structures or events are not visible at all, or are too dark or too light, valuable information may be lost. The onset of bolus transit, and any potential difficulties associated with oral or oralpharyngeal transit, should be clear. In some cases, the difficulty with image quality is patient related, that is, positioning of the patient in a manner that permits good image resolu- 6. In other instances, it may be a lack of attention to , or experience with, the fluoroscopic swallow study that creates difficulty. It is the responsibility of the clinician conducting the study, however, to try to ensure the best quality possible. The patient illustrated in the clip has a tracheostomy tube solely because of his severe dysphagia. However, the cause of this difficulty is not clear until, late in the study, contrast on the fluoro unit is markedly reduced, creating a "whiteout" effect. Another limitation of fluoroscopy is that even with excellent image quality, some features of swallow, such as pressures generated by the mechanical events observed, are not directly assessed, although some may be accurately inferred (Leonard, Rees, & Belafsky, 2006). And, as noted, secretions and residue that adhere to tissues may not be readily visible on fluoroscopy. Finally, the conditions of a fluoroscopic swallow study, including the setting, the use of bolus material, and time and positioning constraints, can have an effect on swallow performance, rendering the study only faintly similar to real-life eating or drinking. Additionally, young children and others who require and are used to being held or otherwise supported physically during feeding are usually denied this because of radiation exposure concerns. These dissimilarities reduce the power of generalizations to eating/drinking in other settings. As stated throughout this text, because fluoroscopy is an invasive tool, the obligation to extract information fully is greater. Yet, the need for complete assessment must be balanced with the risks to respiratory health associated with aspiration. Each step of the dysphagia exam is a way of collecting information that defines aspiration risk for an individual patient. Dynamic Fluoroscopic sWalloW stuDy n performance on clinical evalua- 89 tion of oral, pharyngeal, laryngeal tasks; n effects of diseases and/or their interventions on swallow; and n cognitive/behavioral conditions that interfere with instruction or self-control. If the swallow is not fully assessed because historical or clinical information is unknown beforehand, if all the above factors are not taken into account, if feeding decisions are based only on presence or absence of aspiration during fluoroscopy, then risks to respiratory and nutrition/hydration health can be over- or understated, with obvious consequences for the patient. Other variables that may influence performance include: Position Position of the torso, the head and neck, and the oral, pharyngeal, and laryngeal structures within the head and neck influence swallow performance by altering the effects of gravity on the bolus, the relationships of structures, and shapes of the oral, pharyngeal, and laryngeal chambers. For example, oral transit in a patient with kyphosis can be against gravity and bolus flow through the pharynx biased toward the larynx. Position of the head/neck affects the shape of the pharyngeal chamber and structural relationships. Well-recognized examples include rotation of the head to increase or decrease the size of the piriform sinus spaces or neck flexion aimed at changing the shape of the vallecular space.

In terms of fluid dynamics pregnancy yoga moves order alendronate with a visa, optimal energy transfer is achieved when the area ratio is close to one menstrual nausea vomiting purchase alendronate with a visa, as found here womens health big book of yoga purchase alendronate 70 mg. The relationship of local reflection coefficient pregnancy symptoms purchase alendronate without a prescription, area ratio and junction vessel characteristic impedances can be easily appreciated from the following analysis menstruation quotes tumblr alendronate 70 mg buy low price. We first relate the characteristic impedance of the blood vessel to its geometric and elastic properties. From the waterhammer formula above for the characteristic impedance, we have Zo c r 2 (5. This latter leads to a junction reflection of l If we let 1 nZ m / Z 1 1 nZ m / Z 1 (5. Since reflection is energetically wasteful, this means little energy is lost due to pulse transmission through vascular branching junctions. Also geometric effect rather than elastic effect dominants pulse propagation through vascular branching junctions (Li, 1986). Experimental results showed that minimum reflection is obtained when area ratio equals 1. In small muscular vessels, viscous damping is appreciably more important than in large vessels. The importance of topological geometry and elastic properties at vascular branching junctions can be easily appreciated from the measurement of local reflection coefficients involving characteristic impedances of junction vessels. This indicates that junction geometry is more dominant in determining pulse transmission through vascular branching than elastic factors. Sharply increased reflection coefficient is associated with narrowing branching vessel lumen radius. Reflection is increased with increased branching vessel stiffness, but the increase is less pronounced as compared with corresponding percentage reduction in lumen radius. However, a greater volume of blood is required for perfusion through a vessel with a larger radius, hence a greater demand on metabolic energy: V r 2l (5. The amount of volume flow, Q, is proportional to the square of the lumen radius, r2, assuming the vessel is cylindrical: Q r 2 v (5. The optimal radius is therefore the one that can minimize the resistance to blood flow, as well as the power of expenditure. This can be formulated as: 162 Dynamics of the Vascular System (2nd Edition) Po k1 1 k2r 2 4 r (5. Differentiate Po with respect to r, we have: dPo 4k1 5 2k 2 r 0 dr r Substituting equations (5. It states that in order to achieve a minimum amount of the rate of energy, the blood flow required to perfuse a blood vessel must be proportional to the cubic power of the radius. This stems from the fact that most of the resistance to blood flow are presented by small peripheral vessels (equation (5. They both considered the use of a "cost function" which is commonly used in control systems engineering. The cost function considered is the sum of the rate of work done on the perfusing blood and the rate at which energy is utilized. This results in a cost function in terms of power associated with the flow-vessel interaction: Po Qp k (r 2 l) (5. Minimum rate of work is obtained, by differentiating Pv with respect to r, dPv 32l 5 Q 2 2krl dr r (5. Vascular Branching 165 We have for the cost function that assumes optimum rate of energy usage given by equation (5. Defining an area ratio as the sum of the daughter vessel lumen areas over the mother vessel lumen area, we have: Ar r12 r2 2 r0 2 (5. A modified cost function is one that includes a metabolic constant km and takes into consideration the wall thickness of the vessel, h: Pv (8l 2)Q k (r 2l) km (2rhl) 4 r (5. Blood from capillaries are returned through collecting venules to small veins and to large veins. Hemodynamically speaking, this is because of the large compliance, due to a large incremental volume (dV) and small change in pulsatile distending pressure (dP), viz. Under such condition, venous blood volume, not arterial blood volume, decreases in order to maintain sufficient arterial perfusion pressure. This is accomplished by the 167 168 Dynamics of the Vascular System (2nd Edition) innervation of sympathetic fibers lining the venous walls, stimulation of which causes vasoconstriction, and the narrowing of lumen diameters, hence a reduction in volume of the venous reservoir. Thus, the interplay of reflex action and the volume adjustment, allow venous pressure also to be maintained. Fluid replenishment during hemorrhage is a topic of considerable clinical importance, particularly in reference to hemodilution. Venous pressures are generally low, seldom exceed 12 mm Hg, or 10% of the normal systolic pressure in arteries (120 mmHg). Veins have considerably smaller wall thickness-to-radius ratio (h/r) than corresponding arteries. This gives rise to the reservoir properties of the veins because of their distensibility. In comparison, the walls of veins are much thinner, with less smooth muscle cells, and are less stiff than arterial walls. The large diameter and low pressure of veins permits the venous system to function as a storage reservoir for blood. But the relatively weak wall also makes veins more easily torn under greater shear stress or pressure. Veins acting as a storage reservoir of blood, also exhibit the function of blood distribution. For instance, in muscular parts of the body, such as upper and lower limbs, venous return is aided by the increase in venous tone so that the skeletal muscle pump increases venous pressure to ensure returning of blood to the heart. This is in addition to the peristaltic action of the veins and the one-way flow valves within the veins. The failure of the skeletal muscle contraction can lead to the common phenomenon of "venous pooling" of blood in the venous system of these limbs. Veins also play a major role in body organ temperature control through countercurrent exchanger mechanism. The relatively thin wall of the veins, also contributes greatly to the large the Venous System 169 observed compliance. The collapsibility of the vein is due to several factors including: thin-walled vessel, large compliance, low transmural pressure. The latter is the principal controlling factor, as we shall see in the next section. Despite the differences in structural and mechanical properties between arteries and veins, saphenous vein continues to be the most commonly utilized vessel in coronary artery bypass surgery. The difference in elastic properties between arteries and veins is well appreciated from their differences in distending pressure and wall structure. As mentioned above, venous walls are much thinner than those of correspondingly sized arteries, and are truly thin-walled vessels, i. Because of the collagen elastin composition, they exhibit less elastic recoil, but are easily stretched. Short-term venous blood redistribution can be accomplished by smooth muscle tone, or activation of sympathetic nerve fibers imbedded in the venous walls. Its collapsibility has been debated as to its inefficiency in metabolite transportation and blood flow. It has been shown that for an efficient fluid flow, the vessel ideally needs to be cylindrical. With an eccentricity ratio of 2 (major axis diameter/minor axis diameter), the power required to deliver the same amount of blood is almost twice (125/64) that for a circular vessel lumen. In other words, for a given amount of power, the blood flow through an elliptical vessel lumen is about half (64/125) that of a circular lumen. However, this inefficiency is well made up by the presence of venous valves which arteries lack. These valves serve as auxiliary one-way facilitators that reduce backflow which are energetically wasteful. Thus, the amount of venous return and filling pressure are both important governing factors of 170 Dynamics of the Vascular System (2nd Edition) adequate filling and subsequent ejection. Superior and inferior vena cava are the principal large veins that return blood to the heart. Being in the thorax, the intrathoracic pressure is also an importance consideration. A positive filling pressure must be maintained in these veins to facilitate venous return. This is necessarily so independent of body position, magnitude and distribution of blood volume. Since the vena cavae return blood to the right atrium, it is important that the venous pressure is slightly above the right atrial pressure. This is also necessary to prevent collapse when the difference of intravascular pressure (pi) and extravascular pressure (pe) becomes essentially zero or negative p pi p e (6. In coronary heart diseased subjects, it is not unusual to find filling pressure that exceeds 30 mmHg. During exercise, the increased cardiac output depends also on an increased amount of venous return to the heart. It is recognized that increased sympathetic smooth muscle activation in the venous walls or venous tone in conjunction with compression of veins by surrounding skeletal muscles are important, together with the unidirectional venous valves, in returning blood towards the heart. This view has been deemed important particularly when considering large veins, such as the jugular vein, the main pulmonary vein and the vena cava. The relatively lower elastic modulus and greater compliance are reflected in the mechanical properties of the veins when stress-strain relations are examined. Since veins and arteries are normally structured in parallel and in close proximity to each other, there is usually cross-talk in pulsations, particularly the influence of arterial pressure oscillations on venous pulse waveform. This is seen in the jugular venous pulse, which is often compounded with the high pressure carotid artery pulse. The second major influence of the pulse waveform comes from cardiac chamber pressures, particularly that of the right and left atria. Unlike arterial pressure and flow waveforms, those of veins can vary considerably, subjecting to its collapsibility and external factors. Several 172 Dynamics of the Vascular System (2nd Edition) features can be identified, however, from a typical venous pulse. The c wave is attributed to the carotid artery cross-talk or the systolic bulging of the tricuspid valve during the onset of ventricular systole. These acxvy landmarks in jugular venous pressure waveform can be easily altered with small perturbations, and significantly so in diseased conditions. The jugular venous waveform reflects events occurring in the right atrium and right ventricle. Frequently, landmarks on the recording of the phasic waveform of the jugular venous pulse are often similar to the pressure waveforms of the jugular vein, superior vena cava, and the right atrium. The relation of atrial function and venous flow has been studied by some investigators. A considerable phase difference between arterial inflow and venous outflow was found and attributed to intravascular compliance properties. Moreno (1978) provided recordings of venous pressure and flow waveforms subjecting to such respiratory effects. In an awake, instrumented dog, the respiratory effect is well demonstrated when simultaneous measurements of pulmonary vein pressure and flow, vena caval flow, aortic and pulmonary aortic flows are recorded (Morgan et al. This group of investigators found that vena cava flow reverses during atrial contraction. Benchimol (1981) showed that there can be a prominent h wave, preceding the atrial contraction, associated with abnormal filling beyond the normally identifiable acxvy landmarks. Abnormal filling is particularly relevant in the analysis of venous pressure and flow waveforms. Recordings of jugular pressure pulse often utilize tonometer, while the recording of jugular venous flow uses ultrasound Doppler velocity probe. The placement and angling of this transducer and the applied pressure are critical to the accuracy of the recorded signals. The collapsibility is easily demonstrated by applying even a slight pressure over superficial veins, one can observe both venous pooling (bulging vein) and flow cessation due to occlusion. Transmural pressure is the difference between intravascular and extravascular or ambient pressure: pt pi pe (6. The collapsible tube with flow is connected by rigid connections to two reservoirs. The tube is enclosed in a chamber, containing, say water with an adjustable external pressure pe. Such a resistor is first used by Starling in his heart-lung machine a century ago (Knowlton and Starling, 1912). The amount of flow is dependent on the cross-section of the tube, and hence the transmural pressure. But with this, the cross-sectional area decreases, hence the volume flow which is the product of velocity and cross-sectional area first increases, then becomes limited. The volume flow rate is obtained as the product of the cross-sectional area and the average velocity, i. Conservation of mass states that Q remains constant along the tube, despite that p varies with distance down the tube. Phase velocity of propagation in terms of pressure-crosssectional area relation can be written as c or A dp dA (6.

Although they are a small patient group women's health clinic orange park fl purchase alendronate 70 mg online, treatment of the underlying disorder may improve muscle function and assist in resolution of dysphagic symptoms menopause sleep purchase alendronate 70 mg without prescription, and therefore this diagnosis should be considered in all patients with unexplained oropharyngeal dysphagia women's health tipsy basil lemonade purchase alendronate now. Around half of myositis patients with outlet obstruction will respond to directed treatment such as cricopharyngeal dilation or myotomy (Williams et al pregnancy risk categories 35 mg alendronate order fast delivery. They also show decreased tongue pressures impairing oral control (Hamanaka-Kondoh et al pregnancy 8 months discount alendronate 35 mg buy on line. Choking may become more common with age, and dietary modifications are often implemented to make swallowing easier. Patients may compensate for ptosis by neck extension, which can compound swallowing difficulty. Patients experience prolonged mealtimes and solid and dry food dysphagia followed by liquid dysphagia as the disease progresses (Manjaly et al. Cricopharyngeal dysfunction is common (>75%) and aspiration occurs late in disease. The cricopharyngeus muscle is often affected and may be targeted through behavioral therapy, balloon dilation, and cricopharyngeal myotomy. Videofluoroscopic examination plays an important role in assessment and surveillance in this disorder. All patients reported subjective improvement in swallow disability (as measured by the Sydney Swallowing Questionnaire) and there were no adverse reactions to dilatation. All patients remain on oral diet and the Authors suggest that dilatation be considered instead of surgery in some patients. This may assist in treatment planning, particularly in determining timing of cricopharyngeal intervention, as early intervention may prevent pharyngeal dilatation and failure, formation of hypopharyngeal pseudodiverticuli, or respiratory complications. It is characterized by myotonia, or prolonged muscle contractions, as well as progressive muscle 322 Dysphagia assessment anD treatment planning: a team approach wasting and weakness. Delayed swallowing gestures increase transit time, which is associated with increased risk of aspiration (Leonard et al. Which is more likely to be affected by stroke: oropharynx or hypopharynx function for swallowing Have significant features of swallowing difficulty been identified for patients with muscular dystrophy Do patients with neurological causes of oropharyngeal dysphagia respond to swallowing therapy Do patients with neurological causes of oropharyngeal dysphagia respond to surgical therapy Are there differences in the onset time of swallowing disorders in patients with polymyositis/dermatomyositis compared with patients with limb girdle syndrome Are the effects of postpolio syndrome thought to be solely related to aging that renders compensatory mechanisms previously developed by a patient less effective A prospective assessment of the characteristics of dysphagia in myasthenia gravis. Clinical assessment of orofacial manifestations in 500 patients with multiple sclerosis. Tongue pressure during swallowing is decreased in patients with Duchenne muscular dystrophy. Usefulness of videofluoroscopic swallow study with mixed consistency food for patients with stroke and other brain injuries. Pharyngeal dysphagia in inflammatory muscle diseases resulting from impaired suprahyoid musculature. Measurement of oxygen desaturation is not useful for the detection of aspiration in dysphagic stroke patients. Alpha-synuclein pathology and axonal degeneration of the peripheral motor nerves innervating pharyngeal muscles in Parkinson disease. Current Physical 326 Dysphagia assessment anD treatment planning: a team approach Medicine and Rehabilitation Reports, 4, 287­294. Dysphagia in Duchenne muscular dystrophy: Practical recommendations to guide management. Cough reflex attenuation and swallowing dysfunction in sub-acute post-stroke patients: Prevalence, risk factors, and clinical outcome. Swallowing dysfunction in myotonic dystrophy: A retrospective study of symptomatology and radiographic findings. Biomechanics, diagnosis and treatment outcome in inflammatory myopathy presenting as oropharyngeal dysphagia. Kendall Successful deglutition depends on sensory input from the muscles and the mucosal surfaces of the oropharynx to regulate and fine-tune the sequence of muscular contractions that results in a swallow. It makes sense that disruption of the sensory, muscular, or structural integrity of the oral cavity, pharynx, and larynx causes dysphagia. In patients with head and neck cancer, tumor growth, changes in tissue characteristics secondary to radiation with or without chemotherapy, and any surgical procedure involving the head and neck region, therefore, have the potential to cause dysphagia. This article will focus on the swallowing difficulty experienced by head and neck cancer patients. Surgery to excise the tumor with a margin of normal tissue typically results in a defect with loss of structures needed for normal deglutition. The method chosen for reconstruction of the defect will subsequently influence the restoration of normal anatomic contours and function. Thus, the reconstruction affects the character and the severity of the resultant dysphagia. When postoperative radiation therapy is added to the regimen, dysphagia may worsen secondary to xerostomia and fibrosis of soft tissues in the field of radiation exposure. In recent years, tumors of the oropharynx have been treated with a combination of chemotherapy given concurrently with radiation. Chemoradiation therapy, now used in many cases rather than surgery, avoids removal of the 327 328 Dysphagia assessment anD treatment planning: a team approach tissues involved in the tumor. Administration of intravenous chemotherapeutic agents as radiation sensitizers, combined with concurrent radiation therapy, achieves oncologic outcomes that are similar or better than those outcomes achieved with surgery followed by radiation therapy alone. The rationale behind chemoradiation therapy as primary treatment, rather than surgery followed by radiation, is that "organ sparing" treatment instead of removal of cancerous tissues by surgery should improve functional outcomes. Although tissues are not removed with chemoradiation therapy, intense inflammation of the treated tissues occurs, and ultimately results in tissue fibrosis and weakness of those tissues. Swallowing problems are likely caused by radiation-induced edema and muscular fibrosis. Some patients experience permanent lymphedema resulting in long-term swelling of supraglottic structures. Clinical factors that increase the risk for permanent dysphagia after chemoradiation therapy include increasing patient age, location of the tumor in the larynx or hypopharynx, and increasing size of the tumor (Caudell et al. Pretreatment evaluation All patients diagnosed with head and neck cancer involving the oral cavity, pharynx, and larynx should be considered to be at risk for dysphagia. Prior to treatment, dysphagia can result from either tissue invasion by the tumor or from the tumor obstructing bolus flow. In both cases, the tumor prevents the normal structural displacements needed for bolus propulsion and airway protection. Tumor involvement of sensory nerves also has the potential to impair feedback mechanisms needed for swallowing coordination and may lead to silent aspiration. Several authors have reported that the best predictor of long-term swallowing function in head and neck cancer patients is pretreatment swallowing function (Frowen et al. The location of the tumor in the upper aerodigestive tract also influences the likelihood of pretreatment dysphagia. These authors identified a greater degree of "pharyngeal impairment" on swallowing studies in patients with laryngeal and hypopharyngeal tumors, leading to aspiration (Stenson et al. In addition to tumor location, the size of the tumor further affects the degree of dysphagia, with larger tumors causing a greater degree of swallowing difficulty (Frowen et al. Dysphagia in heaD anD neck cancer patients 329 of the larynx and hypopharynx are at the most risk of developing aspiration, patients with tumors of the oral cavity and pharynx are more likely to report other symptoms such as pain, dysgeusia (distortion of taste), and anorexia that lead to a decrease in dietary intake before treatment (Kubrak et al. Determining aspiration risk in head and neck cancer patients prior to treatment is critical in order to optimize nutrition during treatment and to prevent possible aspiration pneumonia. Swallowing therapy directed toward correcting specific deficits can also be initiated during treatment in an attempt to minimize the long-term effects of the tumor and treatment on swallowing function. Based on these results, successful individualized therapy protocols during head and neck cancer treatment could be designed to address physiologic abnormalities identified on pretreatment swallowing studies. Head and neck cancer patients, therefore, must have a swallowing function evaluation before, during, and after treatment. Chemoradiation therapy causes severe mucositis resulting in odynophagia along with anorexia, loss of taste, and xerostomia that contribute to a decrease in oral intake. During treatment, many patients are not able to maintain their nutritional requirements orally and must have a feeding tube placed. Feeding tubes have been shown definitively to decrease weight loss and the need for parenteral hydration during treatment (Chen et al. As treatment may last as long as eight weeks, a percutaneous gastrostomy, when possible, is preferred over a nasogastric tube for patient comfort. Many centers place feeding tubes in patients prior to the initiation of therapy, regardless of pretreatment weight loss or complaints of dysphagia, in order to minimize the chance that treatment may be interrupted for the placement of a feeding tube (Nguyen et al. However, other centers have identified longer G-tube dependence and a higher incidence of permanent G-tube use in those patients whose G-tubes were placed prophylactically, rather than when clinically indicated by weight loss. There may also be no significant long-term benefits of G-tube placement with respect to weight loss, as patients tend to regain lost weight after therapy. Nonetheless, prevention of weight loss during treatment is critical, as it is associated with an increased risk of cardiac events, pneumonia, renal failure, sepsis, pulmonary complications, wound breakdown, increased urgent hospital admissions, increased length of hospital stay, and overall treatment costs (Gourin, Couch, & Johnson, 330 Dysphagia assessment anD treatment planning: a team approach 2014). Furthermore, weight loss during treatment has been shown to correlate with poor post treatment quality of life scores and swallowing function (Gourin et al. Langmore, Crisciunas, Miloro, Evans, and Cheng (2012) found that those patients who maintained some sort of oral feeding during treatment had better long-term swallowing function than those patients who relied on a feeding tube. Presumably, the continued movement of upper aerodigestive tract structures by swallowing during treatment decreases subsequent fibrosis and movement limitations. Further studies are needed to evaluate the impact of specific swallowing exercises during treatment in preventing long-term dysphagia, even if a patient becomes G-tube dependent during therapy. Clearly, if patients are encouraged to maintain some sort of oral intake during treatment, a pretreatment assessment is imperative to maximize airway safety. Healing from surgery, local edema, other medical conditions, the development of oroor pharyngo-cutaneous fistulae, and the psychological condition of the patient must be factored into the decision. Several studies have found little improvement of swallowing function when the immediate postoperative swallowing is compared with swallowing function as long as one year later (Baker, Fraser, & Baker, 1991; Pauloski, Logemann, & Rademaker, 1994; Pauloski, Rademaker, & McConnel, 1993). However, Pauloski and colleagues were able to demonstrate some functional adaptation and the development of secondary coping strategies in patients after anterior tongue and floor of mouth resections (Pauloski, Logemann, Fox, & Colangelo, 1995). Up to one-half of the lower lip can be excised and closed primarily without serious cosmetic and functional consequences. If greater than one-half of the lip requires removal, local flaps are usually needed for reconstruction. When microstomia results from extensive resection of the lips, the patient will experience difficulty with bolus introduction into the oral cavity. If the resection involves the mental nerve on one or both sides, the subsequent loss of sensation of the lower lip results in surgery Although chemoradiation therapy is now the preferred initial treatment for cancer of the oropharynx, hypopharynx, and larynx, surgery is still considered the mainstay of treatment for small cancers, cancers of the oral cavity, oral tongue, and some early laryngeal cancers. Dysphagia in heaD anD neck cancer patients 331 difficulty in maintaining oral competence, even if the sphincter mechanism remains intact. Lip sensory deficits also cause difficulty in bolus manipulation, and the patient may experience drooling or loss of the bolus during bolus preparation for swallowing. Oral incompetence creates difficulty with the development of intra-oral pressures required to move the bolus from the oral cavity into the pharynx. A lack of hyoid elevation, due to resection or dysfunction of the suprahyoid muscles in the floor of the mouth, results in an inability to open the pharyngoesophageal sphincter. Tongue mobility in the anterior and posterior directions depends upon the pliability of the floor of the mouth region and the attachments of the tongue musculature to the anterior mandible. When tissue is lost from this area, difficulty in bolus preparation and propulsion from the oral cavity into the pharynx results from a loss of tongue maneuverability (Pauloski, Logemann, Fox, et al. Furthermore, lack of contact of the tongue with the pharyngeal constrictors due to anterior tongue tethering will lead to pharyn- geal residue after the pharyngeal phase of swallowing that is often aspirated. If the lingual nerve and the hypoglossal nerve (located in the anterior floor of mouth) are involved in the resection, problems with tongue sensation, taste, and tongue mobility will result. Any closure that results in tethering of the tongue or further loss of tongue bulk - for example, when local tongue flaps are used - will amplify the disability. Surgeons must avoid closing the defect in such a way that the tongue is pulled anteriorly because this will limit posterior tongue mobility, in particular the ability of the tongue to contact the posterior pharyngeal wall. Failure of the tongue to contact the posterior pharyngeal wall during the pharyngeal phase of swallowing will result in poor pharyngeal constriction and residue in the pharynx at risk for aspiration during subsequent respiration. Similarly, if a large or bulky regional flap is inset into the defect, it may displace the tongue too far posteriorly and prevent normal oral manipulation of the bolus. In order to transfer the bolus into the pharynx, the tongue must be able to contact the palate sequentially from anterior to posterior. Skin grafting, local nasolabial flaps, and free tissue transfer (such as the radial forearm or jejeunal flaps) are options for closure of floor of mouth defects. Surgeons performing this type of surgery may consider the addition of a hyoid suspension procedure to open the pharyngoesophageal sphincter permanently, if the suprahyoid musculature has been removed. The degree of impairment is influenced by the location and the extent of the resection (McConnel, Logemann, & Rademaker, 1994). Anterior defects are likely to lead to problems with oral bolus manipulation and difficulty in propelling the bolus into the pharynx, especially if the tongue cannot contact the palate.

Order 70 mg alendronate visa. Dr. Ashton answers viewer health questions.

References