By K. Bufford. Washburn University. 2019.
Bridge to recovery refers to the patient who is expected to recover from heart failure and the device is used to sustain life until the time when it can be weaned off and explanted cheap caduet 5mg free shipping. It will be important not to begin administration of plasma and cryoprecipitate until the plan to proceed with the transplant is certain purchase caduet 5 mg without prescription. The local organ-procurement agency will obtain consent for donation from the family and proceed with the donor evaluation and support order caduet 5 mg amex. The donor evaluation consists of taking a general history of any illnesses or risk factors such as heart disease buy generic caduet 5 mg on-line, hypertension, diabetes, or cigarette smoking. Specifics are gathered surrounding the time and mode of death to determine whether there is any potential cardiac injury, down time, cardiopulmonary resuscitation, or cardioversion. This consists of measuring central venous pressures and, potentially, full hemodynamic profiles if pulmonary artery catheter measurement capability exists at the hospital caring for the donor. The initial stabilization phase should include endocrine support with the administration of levothyroxine and corticosteroids, reduction of inotropic support if it is appropriate, and, potentially, diuresis or transfusion when indicated. A surface echocardiogram is then performed to make sure the heart is structurally normal and that function is normal. It is generally accepted that a cardiac catheterization will be necessary in male donors more than 40 years old and female donors more than 45 years old, but catheterization should also be performed in younger donors when the donor has a significant history of hypertension, cigarette smoking, diabetes, or alcohol abuse. Cardiac enzymes need to be carefully evaluated and correlated to any severe hemodynamic instability, the use of cardiopulmonary resuscitation, as well as the time of herniation . A number of studies have demonstrated correlations between elevations of troponin and early graft failure [19,20]. These data should be analyzed closely with the patient’s hemodynamic function and echocardiographic findings. A transplant center may request that a second echocardiogram be performed if the first echocardiogram was performed shortly after herniation. Catecholamine-induced left ventricular dysfunction can improve significantly in a short period of time and not preclude excellent short-and long-term outcomes. One must also take into consideration the ischemic time that will be incurred with procurement and travel time. The majority of transplant centers are willing to accept an ischemic time up to 4 hours for adult donors but no more than 6 hours. The advent of ex vivo perfusion offers the possibility of warm perfused preservation of thoracic organ grafts. Ex vivo perfusion uses warm oxygenated blood and an extracorporeal pump to perfuse organs during transport and preservation. This technology offers the potential for longer extracorporeal periods and possibly altering the paradigm of cold preservation. During this inspection, one should palpate the coronary arteries to discern any calcifications and also palpate the aortic root for calcifications. External evaluation of the heart is not a reliable evaluation of function unless there is something grossly abnormal, such as severe bruising from a myocardial contusion or a dilated right ventricle. Once it is determined that the heart is appropriate for transplantation and all of the other organ teams are ready, the donor is heparinized and cannulated. If the lungs are being harvested, a pulmonary artery cannula will be placed in the main pulmonary artery. The heart is vented via the left atrial appendage, excised, and is then submerged in ice slush saline, packaged sterilely, and placed in a cooler for rapid transport to the center caring for the recipient. Recipient Operation Once the recipient is prepared and draped, the median sternotomy incision is made and the heart is dissected free of any adhesions, and then cardiopulmonary bypass is established. The recipient is placed on total cardiopulmonary bypass, before the cross-clamp is applied to the aorta, and the heart is excised along the atrioventricular groove. The anastomoses are performed in the following order: left atrial, inferior vena caval, pulmonary arterial, aortic, and superior vena caval . Isoproterenol is used to maintain an appropriate heart rate if bradycardia is a problem or the heart is paced. The pulmonary artery catheter should be floated through the new heart so that pulmonary artery pressures can be monitored closely and any signs of right heart failure can be detected early. Postoperative Care the immediate postoperative management of a heart transplant recipient is by and large not unlike that of other cardiac surgery patients. A pulmonary artery catheter is used with continuous mixed venous oximetry and preload is optimized with either volume or diuretic. Usually patients come out of the operating room on Isuprel (isoproterenol) to stimulate the heart rate and/or the temporary pacemaker set to a back-up rate of 90 to 100 bpm or higher. After the first several days, the heart rate is allowed to drift to its baseline as the cardiac index allows. Occasionally, patients exhibit a distributive shock immediately postoperatively characterized by low systemic vascular resistance and vasopressin or neosynephrine is used to treat it. The ideal patient who is hemodynamically stable and has no signs of surgical bleeding can be extubated within a few hours. Sometimes, patients with right ventricular failure owing to pulmonary hypertension need to be treated with inhaled nitric oxide or epoprostenol (Flolan) and thus mechanical ventilation is continued. These patients have a tendency to bleed more postoperatively and one should keep a low threshold to return to the operating room for exploration if bleeding persists. Serious ventricular failure after cardiac transplantation is unusual and can be related to poor donor-organ selection, poor graft preservation, a long ischemia time, or rejection owing to the presence of preformed antibodies. Early rejection is often heralded by atrial fibrillation and the manifestation of arrhythmias should prompt an immediate workup and treatment. Plasmapheresis can be very effective in removing preformed antibodies responsible for humoral rejection. Inotropes and pulmonary vasodilators are also often used to manage the right heart failure that frequently accompanies rejection, with the addition of an intra-aortic balloon pump if necessary. Immunosuppression Balanced triple-drug immunosuppression is still the most commonly used protocol, consisting of calcineurin inhibitors, an antimetabolite, and corticosteroids (Table 60. Cyclosporine is largely recognized as the agent that moved cardiac transplant from a feasible medical option to an acceptable medical treatment. The physicians at Stanford University performed a randomized controlled trial in cardiac transplant patients that demonstrated that cyclosporine immunosuppression improved 1- year survival to 80% from the mid-50% range . Patients receiving either cyclosporine or tacrolimus have similar survival rates in heart transplantation, both long and short term [24–26]. In addition, median serum creatinine and triglyceride levels were lowest in the tacrolimus and mycophenolate group. Cyclosporine is well known to also cause postoperative hypertension, nephrotoxicity, hepatotoxicity, gingival hyperplasia, hypertrichosis, and tremor. Tacrolimus also causes nephrotoxicity and many of the other side effects of cyclosporine but to a lesser extent, in particular, posttransplant hypertension and gingival hyperplasia. A review article from Stanford confirmed improved survival with the use of tacrolimus and improved postoperative infection prophylaxis . There are multiple regimens for early corticosteroid reduction to avoid the serious associated side effects including systemic hypertension, obesity, osteoporosis, and glucose intolerance. In spite of the negative side effects, in 2004, approximately 75% of patients were still taking corticosteroids 1 year following their transplants . Results from the group at Stanford confirm that therapy with tacrolimus and limited corticosteroid are linked to improved recipient and graft survival . They have shown promise in significantly reducing the severity of cardiac allograft vasculopathy, the main threat of long-term graft survival. But they remain only an adjunct to the calcineurin inhibitors that are still more effective in preventing acute rejection. A significant improvement that has occurred during the current era is the 1-year survival for cardiac retransplantation, which is markedly better than that reported in past eras. General Complications of Heart Transplantation Right Heart Failure and Pulmonary Hypertension Frequently acute right heart failure in the postoperative heart transplant patient is secondary to pulmonary hypertension. As mentioned, patient selection is crucial in identifying those recipients with fixed pulmonary hypertension. Despite this, there are still recipients who will have some degree of pulmonary hypertension that will cause right heart strain posttransplantation. Though right heart failure is frequently accompanied by pulmonary hypertension, other causes include donor selection, poor preservation, or prolonged ischemia time. The need for mechanical assistance typically lasts only a few days to a week and a low threshold should be kept for implanting a device.
In 1) the detection rate of fetal anomalies in the first tri reality safe caduet 5mg, most pregnant women do not have a proper pre‐ mester can never reach that of second‐trimester scan cheap caduet 5 mg with mastercard. For further details buy 5 mg caduet free shipping, must be explained clearly to the pregnant women to refer to Chapter 4 caduet 5mg lowest price. An almost complete fetal morphological assessment is usually feasible Conclusion towards the end of 13 weeks of gestation, but is much more technically challenging at 11 weeks of gestation. The technology is may not be feasible after pregnancy termination, rapidly evolving, and is being expanded rapidly to cover especially if a surgical method is used. By the time this book is published, some of the that require further evaluation and assessment when the details stated here might have become outdated. This may result in signifi However, the principle remains that pregnant women cant psychological stress and emotional disturbance. Am J Med performance of first‐trimester nuchal translucency for Genet A 2009;149A:2716–2722. First thickness and normal karyotype: time for parental trimester serum markers stability during sample reassurance. Ultrasound Obstet Gynecol transportation from the obstetrical site to the screening 2007;30:11–18. Non‐invasive First‐trimester screening for trisomy 18, 13, triploidy prenatal testing for fetal chromosomal abnormalities and Turner syndrome by a detailed early anomaly scan. Ultrasound Obstet Gynecol mosaicism in chorionic villi: results of a monocentric 2014;43:254–264. Fetal fraction in maternal plasma 9 Akolekar R, Beta J, Picciarelli G, Ogilvie C, D’Antonio F. Ultrasound Obstet amniocentesis and chorionic villus sampling: a Gynecol 2013;41:26–32. Ultrasound Obstet Gynecol 4‐week‐pregnant women following in vitro fertilization 2015;45:530–538. Scientific endeavours to mates indicate that over 30 000 women die worldwide determine these elusive vasoactive factors have largely each year because of pre‐eclampsia and its complica- been responsible for pre‐eclampsia being known as the tions, with 98% of these occurring in developing coun- ‘disease of theories’. Globally, pre‐eclampsia has been estimated to Several candidates have been considered in the role of cause between 10 and 25% of perinatal loss [2,3]. Whilst all these elements are death, with six cases reported in the latest triennial subject to modification in pre‐eclamptic pregnancies, it report . Up to 5% of women will develop pre‐eclampsia has not been possible to demonstrate that any have an in their first pregnancy and although the overwhelming initiating role in the disease process. Pre‐eclampsia is a majority of these will have successful pregnancy disease of higher primates only and the lack of a clinically outcomes, the condition can give rise to severe multisys- relevant animal model has been a significant research tem complications including cerebral haemorrhage, obstacle. The discovery of soluble fms‐like tyrosine hepatic and renal dysfunction and respiratory compro- kinase (sFlt)‐1 has been particularly exciting because it is mise. The development of strategies to prevent and treat the first candidate that has been demonstrated to cause a the disorder has been challenging due to an incomplete pre‐eclampsia phenotype in an animal model . The disease can occur in the absence of fetal tissue these factors that usually promote angiogenesis and pla- (molar pregnancy) and manifestations of the disease will centation. Women with pre‐eclampsia have increased only resolve following delivery of the placenta. The prevailing theory has been that the subse- and in vivo studies  have shown that the hypoxic pla- quent relative placental ischaemia causes release of vaso- centa produces increased levels of sFlt‐1 and primate active factors into the circulation which then give rise to studies  indicate that this may be sufficient to produce Dewhurst’s Textbook of Obstetrics & Gynaecology, Ninth Edition. Pre‐eclampsia complicates in pre‐eclampsia and has been shown to augment the 3–5% of all pregnancies, and is characterized by placen- effect of sFlt‐1 and is particularly associated with hepatic tal and maternal vascular dysfunction that may lead to endothelial damage . The diagnosis of pre‐eclampsia, and hence the predic- tion of adverse events, is based on traditional but some- what unreliable and non‐specific clinical markers such as Summary box 7. For example, more than 20% of women who have eclamp- ● the pathogenesis of pre‐eclampsia remains elusive sia will fail to meet the common diagnostic criteria of pre‐ but a greater scientific knowledge of the condition is eclampsia prior to their event, making the prediction of this emerging. For this reason consistency is required both for clinical ● Pre‐eclampsia is the second most frequent cause of management and to allow the comparison of outcomes direct maternal death. This is a stress response gene that has a cellular protec- ● Pre‐eclampsia: new hypertension presenting after 20 tive role, particularly against hypoxic injury. It can be primary or pathway has led to the suggestion that pharmacological secondary in aetiology. There has always been considerable debate over the most ● Mild hypertension: diastolic blood pressure appropriate definition of the hypertensive disorders in 90–99 mmHg, systolic blood pressure 140–149 mmHg. It has been recognized that there are benefits ● Moderate hypertension: diastolic blood pressure 100– in having a broader clinical definition whilst retaining a 109 mmHg, systolic blood pressure 150–159 mmHg. Hypertension ● Severe hypertension: diastolic blood pressure 110 mmHg complicates 6–12% of all pregnancies , and includes or greater, systolic blood pressure 160 mmHg or greater. Hypertensive Disorders 75 situations when the blood pressure approaches zero Summary box 7. The reliable detection of proteinuria is essential in dif- ● Pre‐eclampsia is a multisystem disease diagnosed by ferentiating those pregnancies with pre‐eclampsia from the characteristic appearance of gestational hyperten- those with gestational or chronic hypertension and, in sion and gestational proteinuria. The measurement of significant pro- pressure >140/90mmHg occurring after 20/40 gesta- teinuria, traditionally 300mg excretion in a 24‐hour tion in pregnancy. On its own it carries little additional period, is also prone to collection and measurement morbidity. The collection of 24‐hour urine samples is not ● Gestational proteinuria is a protein excretion above practical as a routine test and so urine dipstick screening 300mg per 24 hours (equivalent to a protein/creati- is employed as a first‐line screening test with secondary nine ratio of 30 mg/mmol). This and proteinuria in pregnancy test has been shown in numerous studies to be compara- and pre‐eclampsia ble to the 24‐hour urine protein estimation . The threshold for defining significant proteinuria by this test the errors associated with blood pressure measurement is 30 mg protein/mmol creatinine. Care in taking these measure- ments will reduce false‐positive and false‐negative results and improve clinical care. Machine/device errors Risk assessment and risk reduction have led to strict validation protocols for automated blood pressure devices in specific populations and clini- There have been attempts to screen the antenatal popu- cal settings  and the human errors inherent in man- lation for pre‐eclampsia over the past 60 years, with over ual readings have led to guidelines on the measurement 100 potential biochemical, biophysical or epidemiologi- of blood pressure with both manual and automated cal candidate tests. Digit preference (the versal test to apply, it is still possible to advise women practice of rounding the final digit of blood pressure to regarding their risk of pre‐eclampsia from their clinical zero) occurs in the vast majority of antenatal measure- history and some investigations. Using a standard bladder in a size that a woman’s risk of pre‐eclampsia should be eval- sphygmomanometer cuff will systematically undercuff uated. Several risk factors for pre‐eclampsia are known 25% of an average antenatal population. Keeping the rate of defla- should be identified at booking to identify women at risk tion to 2–3mmHg/s will prevent over‐diagnosis of of pre‐eclampsia. Many of the risk factors listed in this diastolic hypertension, as will using Korotkoff 5, which is table are modifiable and may lead to a reduction in risk now universally recommended for diagnosing diastolic either prior to or between pregnancies. Korotkoff 4 (the muffling of the sound) is Individual risk is not a simple numerical addition. A less reproducible, and randomized controlled trials con- family history of pre‐eclampsia in a first‐degree relative firmed that it is safe to abandon it, except in those rare is significant and two relatives even more so, whilst 76 Maternal Medicine Table 7. Relative Confidence Any single high‐risk factor risk intervals Hypertensive disease during a previous pregnancy Chronic kidney disease Antiphospholipid syndrome 9. Other factors often associated it did recognize its potential and made a research rec- with increasing age, such as obesity, gestational and pre‐ ommendation regarding its use in the management of gestational diabetes, and any disease affecting the cardi- high‐risk women. No other biophysical test other than accurate meas- the relative risk for pre‐eclampsia for some of these risk urement of blood pressure in the first trimester has factors is shown in Table 7. Numerous haematological women who are high risk will still not develop pre‐ and biochemical markers have been used to both predict eclampsia whilst a considerable number of cases will and evaluate pre‐eclampsia. Identifying have chronic hypertension the measurement of uric acid women at risk will allow increase in surveillance and use and platelets can help in determining those who suffer of prophylactic therapies can be considered. If adequate superimposed pre‐eclampsia; again the tests lack sensi- preventive measures become available, then these tivity and specificity . Furthermore, very few of these screening tests will become increasingly important. The reason for this is that the biomarkers assessment of the maternal uterine circulation is consid- previously studied were mostly generic indicators of vas- ered to be a promising test. This test when ‘positive’ cular activation and dysfunction, which arise late in the demonstrates the high resistance in the uterine arteries pre‐eclamptic disease process and which are not specific as well as a ‘notch’ apparent within the Doppler wave- to pre‐eclampsia or even to pregnancy. These two features have been used in isolation As outlined previously, recent advances have identified and combination to screen low‐ and high‐risk popula- a class of pregnancy‐specific angiogenic and anti‐angio- tions. No other intervention can In 2008, the Society of Obstetricians and Gynaecologists be recommended, including magnesium, folic acid, anti- of Canada Genetics Committee, following systematic oxidants (vitamins C and E), fish oils or bed rest. They also stated that multiple maternal serum screening markers at present should not be used Chronic hypertension for population‐based screening as false‐positive rates are high, sensitivities are low and no protocols have shown Women with chronic hypertension should receive pre‐ improved outcome . This should aim to determine the severity Screening is important to focus resources on high‐risk and cause of the hypertension; review potentially terato- women as well as to identify those in whom prophylactic genic medications such as angiotensin‐converting enzyme therapies might have some benefit.
It has been reported to occur in approximately 20% of patients during autologous bone marrow transplantation caduet 5mg cheap, and it has been associated with mortality rates of 64% to 100% [25–27] order caduet 5 mg on-line. Inspection of the skin and mucous membranes may show telangiectasias order caduet 5 mg line, suggesting hereditary hemorrhagic telangiectasia order caduet 5 mg, or ecchymoses and petechiae, suggesting a hematologic abnormality. Pulsations transmitted to a tracheostomy cannula should heighten suspicion, or risk, of a tracheoartery fistula. Inspection of the thorax may show evidence of recent or old chest trauma, and unilateral wheeze or rales may herald localized disease such as bronchial adenoma or carcinoma. Although pulmonary embolism is not definitively diagnosed on physical examination, tachypnea, phlebitis, and pleural friction rub suggest this disorder. Careful cardiovascular examination and echocardiography may identify mitral stenosis, pulmonary artery stenosis, or pulmonary hypertension. The complete blood cell count results may suggest the presence of an infection, hematologic disorder, or chronic blood loss. In addition, sputum should be sent for cytologic evaluation if the patient is a smoker and older than 40 years. Urinalysis may reveal hematuria and suggest the presence of a systemic disease associated with diffuse parenchymal disease (e. Although there is simultaneous evidence of clinical involvement of the lungs and kidneys in 33% of cases of Goodpasture’s syndrome, there can be clinical lung involvement without renal disease and clinical renal involvement without lung disease. Although as many as 30% of patients with hemoptysis have negative chest radiographs , routine posteroanterior and lateral films may be diagnostically valuable. When pulmonary tumor or infection is not readily apparent, there are other radiographic signs that may help to elucidate the cause and source of bleeding. One may note the disappearance of a calcified mediastinal lymph node after it has eroded the bronchial wall and is expectorated as a broncholith. The finding of a mass within a cavitary lesion raises the possibility of a fungus ball (aspergilloma), whereas localized honeycombing may be indicative of bronchiectasis. The presence of a new infiltrate localized to the area subtending a balloon flotation catheter suggests a rupture of the pulmonary artery [9–11]. The appearance of a new air-fluid level in a preexisting cavity or cyst suggests the location of the source of bleeding, as does a nonsegmental alveolar pattern that clears within a few days. Among patients with hemoptysis due to pulmonary embolism, a parenchymal density abutting a pleural surface with evidence of pleural reaction or effusion is usually present. The cardiac silhouette, vascular or parenchymal patterns, and the presence of Kerley B lines may be useful in documenting cardiovascular disease. This progresses to a mixed alveolar–interstitial pattern and then, when bleeding ceases entirely, to an interstitial pattern, as hemosiderin deposition accumulates [25–27]. Bronchoscopy and Computed Tomography Even if the history, physical examination, and chest radiograph are normal, or there is an “obvious” cause of hemoptysis on the chest radiograph, bronchoscopy is invaluable not only for accurate diagnosis but also for precise localization of the pulmonary hemorrhage. It is not uncommon for bronchoscopy to establish sites of bleeding different from those suggested by chest radiography. Bronchoscopy may not be needed in patients with stable chronic bronchitis with one episode of blood streaking (especially those who are younger than 40 years of age with short-lived hemoptysis of less than 1 week duration where the likelihood of occult malignancy is low), particularly if associated with an exacerbation of acute tracheobronchitis, or in patients in whom the site of bleeding was recently documented by bronchoscopic examination. In addition, patients with acute lower respiratory tract infections, and patients with obvious cardiovascular causes of hemoptysis, such as congestive heart failure and pulmonary embolism, may not require bronchoscopic examination. For localizing the bleeding site, the best results are obtained when bronchoscopy is performed during or within 24 hours of active bleeding. The bleeding site can be localized in up to 93% of patients with a flexible bronchoscope and in up to 86% with the rigid instrument [30,31]. When bronchoscopy is done after bleeding has ceased, accurate localization is likely to be reduced even further [30–32]. Although the flexible bronchoscope is usually the instrument of choice for diagnosing lower respiratory tract problems, rigid bronchoscopy is preferred in cases of massive, uncontrolled hemorrhage because patency of the airway is maintained more effectively during the procedure (see Interventional Pulmonary Chapter 182). With the exception of tracheoarterial fistula, the tracheobronchial disorders that can be diagnosed by a bronchoscopic examination are listed in Table 175. In tracheostomized patients with hemoptysis, bronchoscopy should be performed to rule out other causes, such as bleeding from suction ulcers, tracheitis, or lower respiratory tract disorders. If no other cause for hemoptysis can be found and bleeding has stopped, or anterior and downward pressure on the cannula on the stomal site or overinflation of the tracheostomy balloon slows down or stops the bleeding, a surgical consultation (cardiothoracic and vascular) should be sought immediately and the patient brought to the operating room for examination in a more controlled environment. As long as tracheoarterial fistula remains a diagnostic possibility, the tracheostomy balloon should not be deflated, and the tracheostomy tube should not be removed without protecting the airway below the tracheostomy tube [12,33]. Because carbon monoxide–diffusing capacity is increased because of binding of carbon monoxide by intra-alveolar red blood cells for 24 to 48 hours after bleeding stops, this test may be helpful for suggesting intra-alveolar hemorrhage of the stable patient without hemoptysis but is rarely utilized currently. Clearly for these cases, flexible bronchoscopy will be superior and bronchoscopy also provides the ability to additionally provide stabilizing, temporizing therapeutic interventions in some cases. When performed routinely, diagnostic angiography establishes a diagnosis not identified by bronchoscopy in only 4% of patients . Although angiography may not be initially helpful in confirming the rupture of the pulmonary artery caused by balloon flotation catheterization if the rent has sealed, it can be extremely helpful for detecting a pseudoaneurysm that has formed during the healing process [10,11]. Identification of an unstable lesion is important because it should be obliterated to prevent future rupture and death [10,11]. Angiography has not been shown to be routinely useful for diagnosing tracheoarterial fistula and if the suspicion is high, one should proceed to direct inspection in the operating room with surgical consultant backup and involvement available [12,33]. Special Evaluation Depending on the results of the initial evaluation and the possible categories of cause of hemoptysis (Table 175. The diagnosis of Goodpasture’s syndrome, for example, is made by demonstrating linear deposition of immunoglobulin (Ig) G along the basement membrane of the lung or kidney and the presence of high titers of circulating anti–glomerular basement membrane antibody in the blood. Definitive diagnosis of the pulmonary vasculitides depends on histologic examination, including special stains and cultures that rule out tuberculosis and fungal diseases. Pulmonary capillaritis with hemorrhage has been reported in an ever-increasing number of conditions [4,25–27]. The diagnosis can on rare occasion be made on transbronchial biopsy, thus avoiding the need for open or video-assisted thoracoscopic wedge lung biopsy , but care must be taken to exclude infectious etiologies by using special stains. The diagnostic features of polyarteritis nodosa, the hypersensitivity vasculitides, giant cell and Takayasu’s arteritis, and Behçet’s disease are also presented in detail in Chapter 67. Several cases of Henoch– Schönlein syndrome, one of the hypersensitivity vasculitides, have been reported with severe alveolar hemorrhage, including one in which immunofluorescent stains of the lung revealed granular deposits of IgA consistent with an immune complex mediation. Giant cell arteritis involvement of the lung is suggested by upper respiratory tract symptoms of sore throat, cough, and hoarseness . Although high levels of IgG, IgA, and IgM antibody to trimellitic- coupled protein and trimellitic-conjugated erythrocytes have been found among patients with trimellitic anhydride-induced pulmonary disease , the diagnosis can be made clinically by obtaining a history of the exposure and ruling out other diseases (Table 175. It is important to be aware that diseases may be considered and therefore evaluated in more than one category. For instance, a patient with hemoptysis due to overzealous antithrombotic therapy may be evaluated in three categories: (a) a hematologic disorder that may cause, (b) localized, and (c) diffuse parenchymal disease. A patient with chronic bleeding from the tracheobronchial disorder of diffuse bronchial telangiectasis could present with diffuse as well as localized parenchymal disease (aspiration hemosiderosis). A patient with long-standing passive congestion of the lungs, a cardiovascular disorder, might present with diffuse pulmonary hemosiderosis, whereas a patient with acute pulmonary edema usually presents with diffuse pulmonary infiltrates. Features that can help to differentiate the causes of pseudohemoptysis from one another and pseudohemoptysis from true hemoptysis are found in Table 175. In addition to history and routine physical examination, it is important to perform a meticulous examination of the nose and entire pharynx, preferably with a nasopharyngoscope. Unless the cause of pseudohemoptysis is definitively determined, the spitting up of blood must be assumed to be true hemoptysis until proven otherwise. An upper-airway lesion must not be assumed to be the cause of the bleeding unless it is seen bleeding actively at the time of examination. Not infrequently, the evaluation may require a team approach with the interprofessional involvement and input from a gastroenterologist and an otolaryngologist, as well as the primary evaluating pulmonary and/or critical care specialist. When prescribing definitive therapy, it is important to consider the cause, the amount and rate of bleeding, and the patient’s underlying lung function. The assessment and management of the patient is frequently occurring concurrently based on the pace and urgency of the overall presentation. The basic tenets of management include the following: (1) stabilization, (2) localization/lateralization, and (3) isolation and containment with potential definitive therapy. Drugs with antiplatelet effects also should not be used and any underlying bleeding diathesis should be reversed when possible. Depending on the results of pulse oximetry or arterial blood gas analysis, supplemental oxygen should be given.
This lady was taking very little gluten at the time of the test and the results were therefore those of a coeliac patient taking a gluten-free diet discount 5 mg caduet. Taking the sensitivity and specificity of IgA tissue transglutaminase antibody test- ing in adults as 93 and 96 per cent buy caduet 5 mg lowest price, respectively discount caduet 5 mg overnight delivery, the likelihood ratios of a positive test and a negative test for coeliac disease are as follows: a purchase caduet 5 mg fast delivery. Fagan’s nomogram is used and links the pre-test probability of a condition with the probability when a specific test has been undertaken. It emphasizes the need for a pre-test probability if a test result is to be interpreted effectively – even if this is simply a population-based probability. Serum and urine osmolality were requested and on the basis of the results lithium treatment was stopped. Note focus of pathological uptake in the right-sided adenoma (A) and (C) submandibular glands, (B) Normal uptake in right and left thyroid lobes. Lithium increases intrathyroidal iodine content and inhibits the coupling of iodo- tyrosine molecules to form T4 and T3. Overall, the incidence is up to 30 per cent of patients treated with lithium, with women being affected more often than men. Interferon-related thyroid disease includes destructive thyroiditis, Grave’s thyrotoxicosis and hypothyroidism – the prevalence is variable at 1–35 per cent, with an average about 15 per cent and females affected more than males. In addition, there are a number of drugs which inhibit the absorption of thyroxine: antacids, proton pump inhibitors, bile acid sequestrants and phosphate-binding agents used in chronic renal failure. Antipsychotic drugs, such as olanzapine, are the most likely cause of an elevated prolactin other than pituitary adenomas. Dopamine is the major route for inhibition of prolactin secretion and hence the mechanism of action of some of these drugs. The most frequent cause of this pattern due to osmotic effects is, of course, diabetes mellitus, but other osmotic factors such as mannitol infusions are capable of caus- ing similar effects. In this case, the response to stopping lithium therapy indicated the cause as lithium-induced diabetes insipidus, albeit exacerbated by his gastrointestinal condi- tion and hypercalcaemia. There is a wide range of causes of hypercalcaemia: malignancy (bony metastases, solid tumour humoral effects, myeloma), hyperparathyroidism (primary, tertiary and lithium induced), elevated bone turnover (thyrotoxicosis, immobilization with Paget’s disease), elevated vitamin D (vitamin D toxicity, granulomatous conditions, such as sarcoid), drugs (thiazides), milk-alkali syndrome, familial hypocalciuric hypercalcaemia, other endocrine conditions (acromegaly, Addison’s disease) and rare conditions, e. The patient may complain of drowsiness, fever, sweating, headache, ear ache, nausea, vomiting and thirst. Dehydration is likely to be present and is due to her osmotic diuresis secondary to her hyperglycaemia. The difference is explained by the presence of ions such as sulphate, phosphate and charged proteins, such as albumin. Using saline, rather than Hartman’s, as the initial fluid replacement is reasonable in view of the history of vomiting. Treatment with insulin will cause potassium to enter cells and without adequate replacement hypokalaemia will occur. A patient with hypokalaemia will usually require 80 mmol/day of potassium replacement to restore the serum potassium to normal. It is important to check for any history of head injury and to check for neck stiff- ness, photophobia, petechial, purpuric skin rash as an indication of meningitis. Computed tomography confirmed evidence of right-sided mastoiditis with no bone destruction and this was treated with intravenous antibiotics. Intracerebral abscess as a complication of middle ear infection may also be associated with decreased cognitive function, headache and drowsiness without necessarily being associated with focal neurological signs. The most likely cause for the raised alkaline phosphatase is that she is still growing and this is reflected in her alkaline phosphatase which is of bone orgin. One other possibility in a young woman complaining of vomiting is placental alkaline phosphatase in pregnancy (check pregnancy test). He had been taking antacids for dyspepsia for some time, but this week the antacids did not seem to be working. What was the most likely tonicity of his fluid loss – this may be hypertonic (higher electrolyte concentration than plasma), isotonic (same electrolyte concentration as plasma) or hypotonic (lower electrolyte concentration than plasma)? Is there evidence here that the patient is about to develop acute tubular necrosis of the kidneys – acute renal failure? In addition to pulse and blood pressure postural drop, loss of skin elasticity, increased respiratory rate, thirst, low urine volume and high urine concentration are useful markers of excessive fluid loss, especially isotonic fluid loss. The combination of plasma and interstitial volumes gives the extracellular fluid volume and the intracellular and extracellular, the total body water volume. Interstitial volume = 13 L Intracellular 280 mmol/kg volume = 24 L Sodium rich 280 mmol/kg Potassium rich Intravascular volume = 5 L 280 mmol/kg ure 8. Hence the symptoms of shock are present only following a much greater fluid loss if this is hypotonic. A low urine volume and a high urine concentration together with thirst may be seen with all fluid loss; however thirst is noted more with hypotonic fluid loss. The electrolyte content of his fluid loss through vomiting is shown in comparison with other gastrointestinal losses in the table below. Intestinal Sodium Potassium Chloride Bicarbonate secretion (mmol/L) (mmol/L) (mmol/L) (mmol/L) Gastric 20–60 14 140 0–15 Biliary 145 5 105 30 Pancreatic 125–138 8 56 85 Small bowel 140 5 125 30 Large bowel 60 15 40 – In a young person, the gastric fluid will have a low sodium concentration and zero bicarbonate with the ionic difference being filled by hydrogen ions – about 105 mmol/L. The extent of fluid loss may be assessed in previously fit people by the increase in haematocrit, total protein and albumin concentrations. However, where there is a background chronic disease, anaemia and hypoproteinaemia make interpretation more difficult. While it may indicate fluid depletion, an elevation in creatinine is also affected by pre-existing renal function. Although both the urea and creatinine are raised, the plasma and urine osmolalities indicate the kidney tubules are capable of concentrating urine, and the low urine sodium shows that tubular reabsorption of sodium is effective. The loss of hydrogen ions leaves an excess of bicarbonate in serum as normally this fluid would be reabsorbed and the effect on acid/base balance neutral. Although gastric fluid contains 5–20 mmol/L of potassium, this is not the major reason for the hypoka- laemia, although it does contribute. Poor kidney perfusion causes the release of renin, which then activates the angiotensin system and through this the secretion of aldosterone from the adrenal cortex. Aldosterone promotes the retention of sodium through the exchange of sodium for potassium or hydrogen ions (see ure 8. Furthermore, the exchange of sodium for hydrogen ions in the renal tubules generates bicarbonate, which is already in excess in plasma. Hence in this context, the exchange of sodium is mostly for potassium, thus generating the hypokalaemia. Note: As the plasma potassium falls in the extracellular fluid, potassium leaves the intracellular space to compensate. For this reason, the amount of potassium lost to cause a fall in plasma potassium is considerable – usually a fall of plasma potas- sium by 0. Although Hartmann’s solution is used extensively to cover loss from small bowel, the high chloride loss in this case requires the use of saline initially. This should not be replaced immediately as time must be given for equilibration between extracellular and intracellular spaces. However, more than 40 mmol will be required in the first 24 h and in a fit young person 100 mmol in 24 h is reasonable. Case 8: Man with severe vomiting 43 However, it will be important to check the electrolyte levels but more to ensure that potassium replacement is appropriate. When the kidneys are better perfused, the plasma urea and creatinine will fall, but only when the urine volume has increased sufficiently to excrete the high level of urea in the total body water. Blood alcohol concentrations of 2 g/L are associated with confusion, values of 3 g/L with stupor, 4 g/L with coma and 5 g/L may be fatal. This potentially fatal condition may be missed as there may not be a ketotic odour and Ketostix test may be negative. The possibility of this being due to non-alcoholic fatty liver disease, which is associated with diabe- tes, needs consideration. The elevation in lactate is due to poor oxygenation of tissues and is associated with the opiate-induced respiratory depression. Blood lactate is also elevated in paraceta- mol poisoning and if co-codamol has been taken, then both paracetamol concentra- tion in the blood and a positive screening test for opiates will be present. Another possibility is the effect of carbon monoxide which is associated with lactic acidosis, as is diabetic ketosis. Lactic acidosis is a metabolic acidosis and is defined as a blood lactate concentration above 5 mmol/L, while values between the upper limit of normal and 5. The causes of lactic acidosis may be divided into those associated with (1) hypoxic and (2) non-hypoxic causes. Treatment of lactic acidosis is primarily the removal of the underlying cause plus ensuring adequate oxygenation, and that perfusion is adequate.
It must then be meticulously dissected free without damaging the aortic valve to avoid producing valvular insufficiency discount caduet 5 mg without prescription. C: As an extra precaution against inadequate relief of an obstruction buy caduet 5 mg without prescription, a limited myectomy is also carried out discount caduet 5mg amex. Injury to the Mitral Valve Occasionally caduet 5mg overnight delivery, the lesion may extend and become adherent to the anterior leaflet of the mitral valve; in this case, it should be dissected free with the utmost care. Exposure is facilitated by extending the aortotomy obliquely down to the noncoronary annulus and placing plegeted sutures just above the valve commissures. After the initial wedge resection, a small rake retractor can be placed into the septum and pulled upward toward the aortic annulus to allow visualization and resection of the apical portion of the septum. Two longitudinal incisions, one below the commissure between the left and right leaflets and the other below the nadir of the right cusp are made. Surgery on the Mitral Valve When systolic anterior motion of the anterior leaflet of the mitral valve is a significant component of the left ventricular outflow tract obstruction, an adequate septal myectomy usually resolves the abnormal motion of the anterior leaflet and any mitral regurgitation. However, some patients have associated abnormalities of the mitral subvalvular apparatus, which must be recognized and treated at the time of surgery. These include anomalous papillary muscle insertion directly into the anterior leaflet of the mitral valve and abnormal chordae tendineae attaching to the ventricular septum. If present, the abnormal chords are resected, and any areas of fusion of the papillary muscle(s) to the septum or free wall are divided. Occasionally, a valvuloplasty procedure to shift the coaptation level of the valve posteriorly may be required. A simple technique that may be effective is an Alfieri stitch placed 1 cm away from the free edges connecting the central portion of the anterior and posterior leaflets (see Chapter 6). Rarely, the mitral valve must be replaced with a low-profile prosthesis, resecting the entire anterior subvalvular apparatus. Flail Leaflet All anomalous chords attached to the free edge of the anterior leaflet must be preserved to prevent a flail leaflet. Embolism from Muscle Fragments Falling into the Ventricular Cavity During the process of excising the hypertrophied muscle, fragments may fall into the left ventricular cavity, resulting in a subsequent embolism. This can be prevented to some degree by pulling on the desired segment to be excised with a 4-0 or 5-0 Prolene stitch. Extent of resection the myectomy can be considered complete when the mitral chordae and papillary support apparatus is clearly visualized through the left ventricular outflow tract. A left ventricular apical conduit to the ascending or descending aorta is an alternative, but not a favored one. The Rastan-Konno aortoventricular septoplasty, although a somewhat radical procedure, provides satisfactory results. In infants and children, a Ross-Konno procedure (replacing the aortic root with the pulmonary autograft, completing the ventriculoseptoplasty, and reconstructing the right ventricular outflow tract with a pulmonary homograft) is the operation of choice for this diagnosis. Rastan-Konno Aortoventricular Septoplasty Bicaval and aortic cannulations are made in the usual manner. On cardiopulmonary bypass with moderate cooling, the aorta is cross-clamped and cardioplegic arrest of the heart is achieved by the usual techniques (see Chapter 3). Direction of the Aortotomy the direction of the aortotomy should be as far as possible to the left of the right coronary artery ostium, but not reaching the commissure between the right and left sinuses. The anterior surface of the right ventricular outflow tract is then incised obliquely downward from the aortic root for a distance sufficient to provide good exposure of the interventricular septum. Injury to the Pulmonic Valve the right ventricular outflow tract should be opened before cutting across the aortic annulus to ensure that the native pulmonic valve is not injured. Abnormal Distribution of Right Coronary Artery Branches the possibility of abnormal distribution of right coronary artery branches crossing the right ventricular outflow tract to supply the left ventricular mass must be borne in mind when incising the infundibulum to prevent ischemic injury to the heart. The aortotomy is then continued obliquely downward across the aortic annulus onto the massively thickened interventricular septum. An appropriately sized, oval Hemashield patch of generous width is sewn on the right ventricular side of the interventricular septum, up to the level of the annulus of the resected aortic valve. Reinforcing the Sutures on the Interventricular Septum the interventricular septum is thick and friable; a continuous Prolene suture may tear through it, causing suture leaks and a resulting shunt across the septum. The suture line can be reinforced by buttressing the sutures over a strip of Teflon felt or pledgets on the left or right ventricular side (or both) of the septum. Using interrupted sutures buttressed with pledgets results in surface-to-surface coaptation of the patch to the septum, thereby reducing the possibility of leaks. Maximizing the Enlargement To maximize the left ventricular outflow tract enlargement, the Hemashield patch graft is sewn onto the right ventricular side of the septum. Interrupted valve sutures are inserted into the aortic annulus and through the patch at the level of the annulus (see Chapter 5). After the sutures are inserted through the prosthetic sewing ring, the prosthesis is seated satisfactorily into position. Choice of Prosthesis Because of their early calcification in children, stented tissue valves are not used. Low-profile disc or bileaflet mechanical valves are the preferred prostheses if a pulmonary autograft is not available or contraindicated. Suture Line A new continuous suture should be started at the valve sewing ring and should proceed so that the patch is laid onto the aortotomy incision. A triangular, appropriately generous patch of Hemashield, bovine pericardium, or autologous pericardium is sewn to the edges of the incision on the right ventricular outflow tract and across the first patch at the level of the prosthetic valve. Alternatively, a large pericardial patch is sewn onto the right ventricle and is extended over the aortic patch to secure hemostasis. Reinforcing the Suture Line the suture line can be reinforced with Teflon felt if the right ventricular wall appears to be thin and friable. Once the aortotomy closure is completed, the heart is filled and standard deairing maneuvers are carried out (see Chapter 4). Extended Aortic Root Replacement with an Aortic Homograft or Pulmonary Autograft There are many problems associated with mechanical valves in infants and children. An alternative technique is to combine the concept of aortic root replacement with reimplantation of the coronary arteries and the concept of aortoventricular septoplasty. The aortic, right ventricular, and septal incisions are similar to those described earlier for the Rastan-Konno procedure. If an aortic homograft is used, it is oriented so that the attached anterior leaflet of the mitral valve can be used to patch the incision on the ventricular septum. If a pulmonary autograft is used, a triangular piece of the right ventricular wall can be left attached to the pulmonary valve annulus when harvesting the autograft. Aortic root replacement and reimplantation of the coronary ostia are completed as described in Chapter 5. The patch is sutured to the edges of the right ventriculotomy incision and along the annulus of the valve of the homograft or autograft. Orientation of the Aortic Homograft When the anterior mitral leaflet is left attached to the aortic homograft and used to patch the ventricular septal defect, the homograft must be oriented in only one way. Alternatively, the mitral leaflet can be excised and the ventricular septum enlarged with a triangular patch of Hemashield, which is then sewn to the annulus of the aortic homograft. If the anterior leaflet is used to close the ventricular septal defect, sometimes the arc of the aortic homograft is 180 degrees from the natural arc of the ascending aorta. In this situation, it is often helpful to divide the aortic homograft at the mid- ascending aorta and P. Modified Rastan-Konno Procedure When there is diffuse long-segment tunnel stenosis with a competent aortic valve and adequately sized aortic annulus, a modified Rastan-Konno procedure is indicated. A longitudinal incision is made in the ventricular septum extending from just below the aortic annulus at the commissure between the left and right coronary sinuses proximally on the septum past the area of obstruction. An oval patch of Hemashield is then used to close the defect, placing horizontal, pledgeted, interrupted mattress sutures from the left ventricle through the septum and then the patch on the right ventricular side. Aortic Valve Injury Before making the septal incision, a small aortotomy to allow visualization of the aortic valve and annulus may be useful. A right-angled clamp passed through the aortic valve can identify the appropriate location for the septal incision. Alternatively, sometimes it is helpful to place a large needle from the left ventricular side across the septum to the right ventricular side at the base of the aortic valve, which then marks the superior-most extent of the Konno incision. Injury to the Conduction System the incision on the septum should be well to the left of the right coronary ostium to avoid the conduction system. Inadequate Septal Opening the incision on the ventricular septum must be extended far enough proximally to completely relieve the narrowing of the left ventricular outflow tract.