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Because theca cells do not express aromatase nizagara 50mg amex erectile dysfunction filthy frank, they cannot convert testosterone to estradiol generic nizagara 100 mg on line erectile dysfunction 50 years old. Upon taking a medical history discount 100mg nizagara mastercard erectile dysfunction treatment in kolkata, the physician notes that the patient had regular 28- to 30-day cycles during the past year and engaged in unprotected intercourse. Laboratory tests indicate that her preovulatory (late follicular phase) estradiol is 40 pg/mL (normal, 200 to 500 pg/mL) and midluteal phase progesterone is 3 ng/mL (normal, 4 to 20 ng/mL). Based on the clinical signs, what basic physiological principles provide insight into the infertility? There are two laboratory tests that indicate a problem, the low late follicular phase plasma estradiol concentration and the low midluteal phase plasma progesterone concentration. The low estradiol could be due to the development of a small dominant graafian follicle with insufficient numbers of granulosa cells. The reduced number of granulosa cells would not contain sufficient aromatase to synthesize the high levels of estradiol required during the late follicular phase. The low progesterone during the luteal phase might be due to the ovulation of a small follicle or premature ovulation of a follicle that was not fully developed. Theoretical treatment options for the patient include exogenous progesterone during the luteal phase, which would raise the overall circulating progesterone to levels compatible with maintaining pregnancy, allowing implantation of the embryo. Describe the synthesis of human chorionic gonadotropin and its role in the function of the corpus luteum early during pregnancy. Outline the steps required in the development of the placenta and explain the importance of this organ for steroid production during pregnancy. List the major hormones produced by the cooperation between the maternal compartment and fetoplacental unit, and explain the role of each during the course of pregnancy. Describe the cause, and explain the consequences, of maternal insulin resistance during the latter half of pregnancy. Outline the mechanism(s) that result in parturition, including the function of cortisol, oxytocin, estrogen, and prostaglandins. Explain the roles of prolactin, insulin, glucocorticoids, and oxytocin in lactogenesis. Describe the mechanism through which lactation results in anovulation and suppression of menstrual cycles. Explain the processes that activate the hypothalamic–pituitary axis to initiate puberty and the effect of this activation on steroid output by the gonads. Outline examples of chromosomal and hormonal alterations that result in disorders of sexual development in males and females. Fertilization, the successful union of a sperm and an egg, is the start of pregnancy in a female. The fertilized egg, or zygote, begins to divide immediately after fertilization, and a new life begins. Cell division eventually produces a blastocyst, which enters the uterus and implants itself into the uterine endometrium. Implantation can only occur in a uterus that has been primed by gonadal steroids and is receptive to the blastocyst. The placenta, an organ produced by the mother and fetus, exists only during pregnancy to regulate the supply of oxygen and energy, and the removal of wastes, for the fetus. The placenta also produces protein and steroid hormones that are important for fetal development and maintenance of pregnancy. The fetal endocrine glands regulate important functions in utero including sexual differentiation. Parturition, the expulsion of the fully formed fetus from the uterus, is the final stage of gestation. The onset of parturition is triggered by signals from both the fetus and the mother and involves biochemical and mechanical changes in the uterine myometrium and cervix. After delivery, the mammary glands of the mother must be fully developed and secrete milk to provide nutrition to the newborn baby. The act of suckling, through neurohormonal signals, stimulates milk production and prevents new ovulatory cycles. Sexual maturity is attained during puberty, which occurs at approximately 11 to 12 years of age. The onset of puberty requires changes in the sensitivity, activity, and function of several endocrine organs, including those of the hypothalamic– pituitary–gonadal axis (Clinical Focus 38. Follicular growth is monitored by measuring serum estradiol concentration and by ultrasound imaging of the developing follicles. Approximately 34 to 36 hours later, oocytes are retrieved from the larger follicles by aspiration using laparoscopy or a transvaginal approach. Oocyte maturity is judged from the morphology of the granulosa cells and the presence of the germinal vesicle and first polar body. The donor’s sperms are prepared by washing, centrifuging, and collecting those that are most motile. After 24 hours, the eggs are examined for the presence of two pronuclei (male and female). Embryos are grown to the four-cell to eight-cell stage, about 60 to 70 hours after their retrieval from the follicles. Approximately three embryos are often deposited in the uterine lumen to increase the chance for a successful pregnancy. To ensure a receptive endometrium, daily progesterone administrations begin on the day of retrieval. The oviduct facilitates the movement of the gametes toward each other, and after fertilization provides nourishment for the developing embryo while transporting it to the uterus. Cilia and smooth muscle transport the gametes toward each other within the female genital tract. During intercourse, a fertile man will deposit 2 to 6 mL of semen, the ejaculatory fluid containing 20 to 30 million sperms per milliliter, in the vagina of a woman at the time of ejaculation. Only about 50 to 100 sperms will reach the ampulla of the fallopian tube for fertilization. Major losses of sperm occur in the vagina due to the acidic pH, in the uterus due to phagocytosis by leukocytes, and at the uterotubal junction. Sperm motility; muscular contractions of the vagina, cervix, and uterus; ciliary movement; peristaltic activity; and fluid flow in the oviducts assist transport of the sperms to the ampulla. Sperms remain motile for up to 4 days in the female reproductive tract; however, the capacity for fertilization is limited to 1 to 2 days. Sperms undergo final maturation within the oviduct in a process called capacitation. As sperms develop in the epididymis of a male, surface glycoproteins are acquired that act as stabilizing factors, but which prevent the interaction of sperm and egg. During capacitation, surface glycoproteins are removed, membrane cholesterol is depleted increasing plasma membrane fluidity, and sperm motility increases. Capacitation can occur anywhere in the female reproductive tract where pH is elevated, as shown when sperms are deposited in the intraperitoneal cavity near the fimbria during assisted fertilization procedures. Sperms can also undergo capacitation in chemically defined medium during in vitro fertilization. Ciliated fingerlike projections of the oviducts, called fimbria, grasp the ovum and propel it into the oviduct.
Penicillinase-resistant penicillins such as methicillin are useful for penicillinase-producing staphylococci generic nizagara 25 mg online erectile dysfunction guidelines. Broad-spectrum penicillins generic 100 mg nizagara with mastercard impotence tumblr, ampicillin cheap nizagara 100mg with visa erectile dysfunction doctor in jacksonville fl, and amoxicillin, have better gram-negative coverage, and semisynthetic penicillins such as carbenicillin and ticarcillin extend coverage to Pseudomonas, Enterobacter,and Proteus spp. Immediate allergic response to penicillin, such as hives or anaphylaxis, is a strong contraindication for its use, and there is 10% cross-reactivity with cephalosporins. Therefore, for patients with penicillin allergy, cefazolin should be replaced with vancomycin. Vancomycin is a complex glycopeptide that inhibits bacterial cell-wall synthesis with principally gram-positive coverage, including methicillin-resistant S. As mentioned above, an aminoglycoside is synergistic with cell wall-inhibiting antibiotics, and the patient should be started on fortified vancomycin and tobramycin. Give the patient four doses-an alternating dose every 5 minutes-followed by alternation every half hour. Next morning the ulcer looks worse with 4 mm corneal infiltrate and purulent material overlying the ulcer. Next day, the ulcer looks stable, but the patient complains of persistent and perhaps worsening pain. Examination reveals diffuse punctate corneal epithelial defects, inferior conjunctival erythema, and swollen lower eyelids. Toxicity is often less severe with topical administration; indeed, some common topical antibiotics such as neomycin and polymyxin cannot be given intravenously because of systemic toxicity. However, intensive regimens of potent antibiotics often produce surface toxicity with prominent involvement of lower more than upper conjunctiva. Occasionally, only analgesics and cool compresses can be offered if the infection is not under control. Fortified vancomycin may be decreased because tobramycin and ciprofloxacin are more important for Pseudomonas ulcer, and the ulcer appears to be stabilizing. He would like binocular vision for his surgical career and asks you to get rid of his corneal scar. When, how much, and how long to use topical steroids is controversial, but a trial of topical steroids is certainly warranted before considering surgical options. Fluoroquinolones every ½ to 1 hour initially may offer similar efficacy with less toxicity than fortified topical antibiotics. The use of topical steroids after the infection is controlled can decrease the size of the scar. At a molecular level, inhibition of arachidonic acid release from phospholipids may be the most important effect. Arachidonic acid is converted to prostaglandins and related compounds that are potent mediators of inflammation. At a cellular level, steroids must be carried to the cytoplasm, where they bind to soluble receptors and then enter the nucleus to alter transcription of various proteins involved in immune regulation and inflammation. At the tissue level, steroids suppress the cardinal signs of inflammation such as edema, heat, pain, and redness through a variety of mechanisms. They cause vasoconstriction and decrease vascular permeability to inflammatory cells. Cellular and intracellular membranes are stabilized to inhibit release of inflammatory mediators such as histamine. Neutrophilic leucocytosis is inhibited, and macrophage recruitment and migration are also decreased. Overall, steroids are potent anti-inflammatory and immunosuppressive agents with wide-ranging ophthalmic applications, but their adverse effects as well as their benefits should be understood before use. Since steroids are not cures, what general categories of disorders warrant ophthalmic use of topical steroids? Abelson and Butrus identify three broad categories of disorders that warrant steroid use: postsurgical, immune hyperreactivity, and combined immune and infectious processes. Remarkably, postoperative use of steroids has not been evaluated in a well-controlled, double- blinded study. Although their use in this setting is almost universal, some ophthalmologists report adequate control of postoperative inflammation with topical nonsteroidals for various ophthalmic procedures (controversial). The second category includes various uveitides, allergic and vernal conjunctivitis, corneal graft rejections, and other processes in which the immune system activity is harmful to the host tissue. The last category includes viral and bacterial corneal ulcers, especially herpes simplex and herpes zoster, in which control of infectious processes must be balanced with control of inflammation that may scar delicate ocular tissue. The physician with the residual corneal scar wants to minimize his corneal scar but is concerned about potential side effects of topical steroids. Exacerbation of the existing infection with reactivation of dormant organisms or inhibition of wound healing is the most immediate concern. Other well-known adverse effects include glaucoma and cataracts, but numerous other side effects have been observed, including blepharoptosis, eyelid skin or scleral atrophy, and mydriasis. Systemic absorption may be significant, and punctal occlusion should be encouraged. Of course, all of these effects are more frequent with intensive and chronic use of steroids. However, given his interest in pharmacology, he requests a brief discussion of the pharmacokinetics of a few of the available topical steroids. Nevertheless, 1% prednisolone phosphate achieves a significant corneal level of 10 mg/gm within 30 minutes after instillation, which improves to 235 mg/gm when the corneal epithelium is removed. Dexamethasone phosphate enters the cornea and anterior chamber within 10 minutes, reaches a maximum in 30–60 minutes, and slowly disappears over the next few to 24 hours. The patient also requests that the most potent steroid be used with rapid taper so that the overall course may be shortened. Anti-inflammatory effects of topical steroids differ depending on the clinical setting and method of measurement. However, certain generalizations can be made: & Higher concentrations and more frequent instillations, up to every 5 minutes, increase concentrations of steroids in the cornea and aqueous. His scar is beginning to recede, but he returns 2 days later with complaints of a white precipitate that forms in his conjunctiva and insists on a change of medication to prevent this annoying buildup. In addition, despite shaking the bottles before instillation, a variable amount of the suspension may be delivered if particles are not evenly distributed. Therefore, some ophthalmologists prefer phosphate solutions despite lower potency with intact epithelium. A change to 1% prednisolone phosphate is reasonable if patient compliance is improved. On day 10 of steroid therapy, the corneal scar is receding rapidly, but the patient complains of foreign-body sensation. Steroids do not cause herpetic keratitis but may promote herpetic keratitis when viral shedding is timed with the presence of steroids on the ocular surface. Often the dendrites are large and numerous in the presence of steroids, and steroids should be stopped or rapidly tapered.
Recall that the whole purpose of arterial pressure is to cause blood tofw through tsues buy nizagara on line erectile dysfunction treatment in bangladesh. Thus buy generic nizagara line impotence fonctionnelle, it makes little long-term sense to increase arterial pressure by throttling blood fow with refex arteriolar constriction purchase 100 mg nizagara fast delivery erectile dysfunction treatment at gnc. Because blood volume is one of the components of the total body fluid, blood volume alterations accompany changes in total body fluid volume. The mechanisms are such that an increae in arterialpressure causes an increase in uri nary output rate and thus a decreae in blood volume. But, as outlined in the pre ceding sequence, decreased blood volume tends to lower arterial pressure. Tus, the complete sequence of events that are initiated by an increase in arterial pres sure can be listed as follows: i Arterial pressure (disturbance) J i Urinary output rate J J Fluid volume J J Bloodvolume J J Cardiac output J J Arterial pressure (compensation) Note the negative feedback nature of this sequence of events: increased arterial pressure leads to fluid volume depletion, which tends to lower arterial pressure. Conversely, an initial disturbance of decreased arterial pressure would lead to fuid volume expansion, which would tend to increase arterial pressure. Because of negative feedback, these events constitute afuid volume mechanism for regulat ing arterial pressure. As indicated in Figure 9-5, both the arterial baroreceptor refex and this fluid volume mechanism are negative feedback loops that regulate arterial pres sure. Although the arterial baroreceptor reflex is very quick to counteract distur bances in arterial pressure, hours or even days may be required before a change in urinary output rate produces a signifcant accumulation or loss of total body fluid volume. Whatever this fluid volume mechanism lacks in speed, however, it more than makes up for that in persistence. As long as there is any inequal ity between the fluid intake rate and the urinary output rate, fluid volume is changing and this fuid volume mechanism has not completed its adjustment of arterial pressure. The fuid volume mechanism is in equilibrium only when the urinary output rate exactly equals the fuid intake rate. The processes that regulate voluntary fluid intake (thirst) are not well understood but seem to involve many of the same factors that infuence urinary output (eg, blood volume and osmolality). Preventive and Social Medicine is comparatively a improvement in economic condition or education and newcomer among the academic disciplines of medicine. Previously it was taught to medical students as hygiene Among the developing countries, India gave a lead and public health. This name was later changed to for bringing about the total well being of rural people preventive and social medicine when it was realized that by instituting the remarkable Community Development the subject encompassed much more than merely the Program (1951). For intensive all-round development, principles of hygiene and sanitation and public health the country was divided into Community Development engineering. The name preventive and social medicine Blocks in which ill-health was to be fought through the emphasizes the role of: (a) disease prevention in general agency of primary health centers as recommended by through immunization, adequate nutrition, etc. It may be mentioned that the addition to the routine hygiene measures, and (b) social concept of public health was fairly well developed in factors in health and disease. Adequate proof of community health The name preventive and social medicine has gained measures adopted during Harappa Civilization as far as wide acceptance in the past twenty-five years or so 5000 years ago has been found in the old excavations because of its broader and more comprehensive at Mohenjo-Daro and at Lothal near Ahmedabad in the outlook on medicine, integrating both prevention and form of soakpits, cesspools and underground drainage. Today, it implies a system of total health care delivery to individuals, families and communities at the Public Health, Preventive clinic, in the hospital and in the community itself. Medicine, Social Medicine and Community Medicine Historical Background Traditionally, a young man planning to enter the medical During last 150 years, there have been two important college has in mind the picture of a patient in agony, “revolutions”. The industrial revolution in 1830 was in relieving whose suffering by medicines he considers associated with the discovery of steam power and led himself to be amply rewarded. He always thinks of to rapid industrializations, resulting in concentration of alleviating the suffering of a patient but rarely about the wealth in the cities and, consequently, migration from prevention of such suffering at the level of the individual rural to urban areas. No doubt he has hand the villages were neglected and, on the other, the to play a very important role in meeting the curative towns and cities witnessed rapid haphazard expansion, needs of society but that is not all. But now brought in their wake and more complex health the developing society, in India and elsewhere, expects problems in rural as well as urban areas which ultimately much more from the doctor, and the people are led to development of the concept of public health. The gradually becoming more and more conscious of their social revolution occurred around 1940, during the health needs. The social revolution brought into in the fact that the subject has been practised in the past force the concept of ‘Welfare State’. It was aimed at Public Health fighting the three enemies of man-poverty, ignorance and ill-health on a common platform. This followed the It was defined by Winslow (1851) as the science and realization that health was not possible without art of preventing disease, prolonging life and promoting health and efficiency through organized community With the advent of the specialty of preventive medicine, measures such as control of infection, sanitation, health emphasis was also given to prevention of diseases. Public These included not only infective diseases but also others Health developed in England around the middle of the such as nutritional deficiency diseases. Edwin Chadwick, a pleader, the then Secretary of Poor Law Board (constituted under Social Medicine Poor Law Act passed in 1834) championed and cause of community health and the first Public Health Act was It is defined as the study of the man as a social being passed in 1848. It is concerned with the health Public Health in India followed the English pattern of groups of individuals as well as individuals within but the progress was extremely slow during the British groups. The of social medicine is based upon realization of the Public Health Departments started as vaccination following facts: departments and later as Sanitation Departments at the • Suffering of man is not due to pathogens alone. There can be partly considered to be due to social causes was a long tussle whether the Sanitation or Public Health (social etiology). Department should be responsible directly to the • The consequences of disease are not only physical Government or to the Surgeon General-in-Charge of (pathological alterations due to pathogens) but also Hospitals and Medical Education. Sanitary Commissioner were changed to those of • Social services are often needed along with medical Director and Assistant Director of Public Health. The Royal Commission nued in India even after independence for some time, on Medical Education substituted in 1968 the term though the idea of integration started at the beginning social medicine by community medicine in its report of the Second World War. Preventive and Social Medicine Preventive Medicine As clarified above, preventive medicine and social medi- Preventive medicine developed as a specialty only after cine cover different areas, though both are concerned Louis Pasteur propagated in 1873 the germ theory of with health of the people. This is why the combined disease followed by discovery of causative agents of name Preventive and Social Medicine was suggested to typhoid, pneumonia, tuberculosis, cholera and provide a holistic approach to health of the people. It gained further name was preferred to the earlier name public health impetus during subsequent years from the following because the former had come to be visualized as a developments: discipline dealing mainly with sanitation, hygiene and • Development of several specific disease preventive vaccination. However, the term public health has now measures before the turn of the century (antirabies once again become fashionable in England. It has been defined as “The field concerned with the • Discovery of modes of transmission of diseases study of health and disease in the population of a caused by germs. Its goal is to identify the fever and sleeping sickness had been elucidated health problems and needs of defined populations before the turn of the century. The modern • First vaccine developed: Smallpox day message is that the discipline variously labelled in • Term vaccination: Edward Jenner the past as public health or preventive and social • Term vaccine: Louis Pasteur medicine cannot be divorced from health care, including • Citrus fruits in prevention of scurvy: James Lind clinical care of the community. It is in recognition of this • John Snow: Cholera • William Budd: Typhoid wider role that the Medical Council of India has recently • Robert Koch: Anthrax decided to label the discipline as Community Medicine • Germ theory of disease: Louis Pasteur in place of Preventive and Social Medicine. In a recent • Multi-factorial causation of disease: Pattenkoffer case decided by the Supreme Court of India the issue • Social medicine: Virchow was whether the Department of Preventive and Social • Growth chart: First designed by David Morley • First country to socialize medicine completely: Russia Medicine in a Medical College is a Clinical or Paraclinical • First country to introduce compulsory sickness insurance: Department. Germany Som e m ilestones and history of public health: • Father of Medicine: Hippocrates (Greatest physician in Greek medicine) References • Father of Indian Medicine: Charak 1.
The identifica- tion of multiple small echoes in pleural fluid that move with cardiac and respiratory excursions is known as the “echogenic swirling” sign (Figure 5 order discount nizagara on line erectile dysfunction reddit. In contrast order nizagara 25 mg on line erectile dysfunction caused by ptsd, a nonechogenic fluid collection may be due to either transudate or exudate generic 100mg nizagara with amex erectile dysfunction female doctor, and there- fore this sign should be used for positive identification of exudates only where echogenic swirling is observed. Heavily echogenic fluid, observed as increased echo signals within pleural fluid in a homogenous manner with no particular structure, has been associ- ated with causes of effusion resulting in dense pleural fluid collections, including thick pus and hemothorax9 (Figure 5. Empyema associated with thick pus may demonstrate multiple and brightly reflecting areas within the fluid, characteristic of air bubbles within an infected collection (Figure 5. Air may also be present within an effusion c in the case of bronchopleural fistula or subsequent to U Figure 5. The floating and swirling echoes within the fluid are suggestive of an exudative cause of the effusion. Causes of dense pleural fluid collections like this include thick pus and hemothorax. There is easily deformed as a result of pleural fluid movement some early evidence that the presence of sonographic (Figure 5. Any effusion that is present for a prolonged these findings have not as yet been confirmed in a pro- period may become septated (including transudates), spective study. Adjacent to ening may demonstrate a vascular pattern more the fluid is the air that produces reflection artifact similar to a vascularized tissue than the chaotic color and through which distal structures cannot be appre- sign observed with pleural fluid. Although the appearance of the pneumo- The appearance of pneumothorax at thoracic ultra- thorax may be mistaken for lung, the pneumothorax sound is described in detail in Chapter 7, but the lacks the normal pleural sliding sign (see Chapter presence of both free fluid and air (hydropneumo- 4) and, importantly, will move in a chaotic manner thorax) produces a particular appearance. In this case, in line with the cardiac and respiratory excursions fluid is seen (usually basally according to gravity) as (Figure 5. Pleural effusion is seen basally (with the intermittent appearance of lung in this case), and free air in the pleural space above the effusion is distin- guished from normal lung by the absence of normal lung sliding and movement in a chaotic manner. Quantification of pleural Echogenic swirling pattern as a predictor of malignant effusions: sonography versus radiography. Ultrasound estimation of volume of pleural fluid in Transthoracic ultrasonography in predicting the outcome mechanically ventilated patients. Intensive Care Med 2006; of small-bore catheter drainage in empyemas or com- 32(2):318–321. Thoracic ultra- a useful indicator for discrimination between pleural sound in the diagnosis of malignant pleural effusion. Safety and yield of ultra- pleural lesions: new observations regarding the probability sound-assisted transthoracic biopsy performed by of obtaining free fluid. Value of sonography in determining the nature of pleural effusion: analysis of 320 cases. Lung abnormalities affect the lungs (atelectasis, consolida becomes sonographically visible when pathological tion, abscess, and tumor), heart (pericardial effusion), processes replace air within the subpleural parenchyma. This produces a unexpected pericardial effusion when imaging characteristic “hockey stick” appearance, and improves pleural effusions). Review of any preexisting imaging, particularly cross sectional, prior to ultrasound is essential in predicting likely findings and can aid image interpretation. This is particularly important for the trainee sonographer, who may otherwise fail to detect a lesion or misinter pret abnormalities. If the proximal volume loss and is often triangular or hockey cause is sufficiently large (pulmonary tumor- stickshaped and is usually surrounded by pleural usually larger than 3 cm, or large volume lympha fluid. When this consolidation abuts the pleura, it is visible at ultrasound and appear ●● Hypo or hyperechoic nonaerated lung without ances may mimic the liver. Ultrasound often underestimates the extent of pneu monia, as it fails to detect consolidation not in conti nuity with the pleura. Differentiation is possible with color mally invasive adenocarcinoma and invasive adeno Doppler (Figure 6. U Lung abscesses Tumors These are usually seen associated with pneumonia and Subpleural lung tumors may be visualized (and vary in size and number. Parietal pleural infiltration small abscesses using ultrasound that would otherwise (indicating a T3 tumor) may be suggested by a loss fail to be detected on chest xray, or suspected clini of pleural sliding and confirmed when there is visible cally. Importantly, the demonstration for microbiological culture when the abscess is sono of sliding confirms a T2 tumor, but only the demon graphically visible (i. Tethering Previous or ongoing pleural insults (such as pleural ●● Subsequently, consolidation becomes increas infection, chemical pleurodesis, and malignancy) can ingly heterogeneous with a visible central hyper- cause adherence between parts of the visceral and echoic bronchus. Signs include a disproportionately large Some physicians advocate the use of thoracic ultra right ventricle (compared to the left), a poorly sound in detecting pulmonary emboli,10 but this has contracting right ventricle, and intraventricular not gained widespread acceptance due to the high septal bowing to the left. Large central emboli may not cause While ultrasound features may suggest pulmonary any detectable abnormalities. These are seen as multiple equally spaced erbation during acute respiratory failure. On imaging, these are seen as costophrenic recesses, although partial views may be nearvertical lines radiating out from the pleural obtained by angling the probe upward and scanning stripe and extending to the bottom of the image. In the presence of pleural fluid, good views are possible and five alternating hyper- Pathology of the alveoli and interstitium (e. An artifactual “diaphragmatic increases the number of comet tails, which also become gap” is occasionally seen, appearing as an apparent visible in nondependent locations (see Chapter 10). This is due to ultrasound wave These changes are considered significant when more refraction (causing poor return of the ultrasound beam than three comet tails are seen in two different ultra to the transducer); repositioning the probe will confirm sound fields obtained from the same hemithorax. While being nonspecific, increased comet tails may 78 Pleural ultrasound for CliniCians P n U Figure 6. View nodularity (visceral nodularity not demonstrated on this e-book for ultrasound clip or watch it at http://goo. The diaphragmatic pleural surface is a common site of Large pleural effusions may cause flattening or metastases, which appear as nodules or larger masses inversion of the diaphragmatic dome (Figures 6. Muscular dia associated with significant dyspnea; removal of fluid phragmatic contraction can cause wavelike ridges in the sufficient to restore diaphragmatic configuration diaphragm that may be misinterpreted as nodules, and usually causes significant symptomatic benefit. Ultrasound is well suited to the assessment of possible be assisted by asking the patient to sniff. Diaphragmatic diaphragmatic paralysis, allowing realtime visualization paralysis is associated with a raised hemidiaphragm, of diaphragmatic motion. Other diaphragmatic pathology, such as herniae, Physiologically, during inspiration the peripheral may be also be encountered at ultrasound. A large muscular part of the diaphragm contracts and becomes hiatus hernia may mimic an echogenic pleural space, shorter and thicker, pulling the diaphragmatic dome risking inappropriate chest tube insertion (Figure 6. Nevertheless, it is right parasternal, apical, and subxiphoid or subcostal important for a physician to be competent in: views. However, the easiest way to visualize the heart in the setting of a pleural effusion is with the patient sat ●● Locating the heart. While the standard curvilinear ultrasound probe is not The heart’s dense hyperechoic musculature sur used for detailed echocardiography, it provides reason rounding anechoic chambers undergoing rhythmic able images of the heart, particularly in the presence of contraction is usually easily visible; however, color a leftsided pleural effusion that provides an “acoustic Doppler may provide further confirmation where window” through which the heart may be visual pleural anatomy is very complex. Where available, avoiding the pleural space, may be helpful in this setting a phasedarray echocardiography probe (which has a and is helpful when looking for pericardial effusions smaller footprint) may provide better views through and right heart pathology. A large chronic pericardial effusion may be the triad of low blood pressure, distended neck veins, associated with remarkably few symptoms (e.