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C. Aila. Mississippi State University.

Studies in human lactation: Milk volumes in lactating women during the onset of lactation and full lactation 100 mg zenegra overnight delivery erectile dysfunction over 75. A semiparametric transfor- mation approach to estimating usual daily intake distributions purchase zenegra with paypal erectile dysfunction vasectomy. Inaccuracies in self-reported intake identified by comparison with the doubly labelled water method discount zenegra 100mg amex erectile dysfunction treatment operation. Food and nutrient exposures: What to con- sider when evaluating epidemiologic evidence. Reproducibility and validity of a semiquantitative food fre- quency questionnaire. The fact that diets are usually composed of a variety of foods that include varying amounts of carbohydrate, protein, and various fats imposes some limits on the type of research that can be conducted to ascertain causal relationships. The avail- able data regarding the relationships among major chronic diseases that have been linked with consumption of dietary energy and macronutrients (fats, carbohydrates, fiber, and protein), as well as physical inactivity, are discussed below and are reviewed in greater detail in the specific nutrient chapters (Chapters 5 through 11) and the chapter on physical activity (Chapter 12). Early studies in animals showed that diet could influence carcinogenesis (Tannenbaum, 1942; Tannenbaum and Silverstone, 1957). Cross-cultural studies that com- pare incidence rates of specific cancers across populations have found great differences in cancer incidence, and dietary factors, at least in part, have been implicated as causes of these differences (Armstrong and Doll, 1975; Gray et al. In addition, observational studies have found strong correlations among dietary components and incidence and mortality rates of cancer (Armstrong and Doll, 1975). Many of these associations, however, have not been supported by clinical and interventional studies in humans. Increased intakes of energy, total fat, n-6 polyunsaturated fatty acids, cholesterol, sugars, protein, and some amino acids have been thought to increase the risk of various cancers, whereas intakes of n-3 fatty acids, dietary fiber, and physical activity are thought to be protective. The major findings and potential mechanisms for these relationships are discussed below. Energy Animal studies suggest that restriction of energy intake may inhibit cell proliferation (Zhu et al. A risk of mortality from cancer has been associated with increased energy intakes during childhood (Frankel et al. Excess energy intake is a contributing factor to obesity, which is thought to increase the risk of certain cancers (Carroll, 1998). To support this con- cept, a number of studies have observed a positive association between energy intake during adulthood and risk of cancer (Andersson et al. Dietary Fat High intakes of dietary fat have been implicated in the development of certain cancers. Early cross-cultural and case-control studies reported strong associations between total fat intake and breast cancer (Howe et al. Evidence from epidemiological studies on the relationship between fat intake and colon cancer has been mixed as well (De Stefani et al. Howe and colleagues (1997) reported no asso- ciation between fat intake and risk of colorectal cancer from the com- bined analysis of 13 case-control studies. Epidemiological studies tend to suggest that dietary fat intake is not associated with prostate cancer (Ramon et al. Giovannucci and coworkers (1993), however, reported a positive association between total fat consumption, primarily animal fat, and risk of advanced prostate cancer. Findings on the association between fat intake and lung cancer have been mixed (De Stefani et al. Numerous mechanisms for the carcinogenic effect of dietary fat have been proposed, including eiconasanoid metabolism, cellular prolifera- tion, and alteration of gene expression (Birt et al. Experimental evidence suggests several mechanisms in which n-3 fatty acids may protect against cancer. Epidemiological studies have shown an inverse relationship between fish consumption and the risk of breast and colorectal cancer (Caygill and Hill, 1995; Caygill et al. Monounsaturated fatty acids have been reported as being protective against breast, colon, and possibly prostate cancer (Bartsch et al. However, there is also some epidemiological evidence for a positive asso- ciation between these fatty acids and breast cancer risk in women with no history of benign breast disease (Velie et al. There may be protective effects associated with olive oil (Rose, 1997; Trichopoulou et al. Dietary Carbohydrate While the data on sugar intake and cancer are limited and insufficient, several case-control studies have shown an increased risk of colorectal cancer among individuals with high intakes of sugar-rich foods (Benito et al. Additionally, high vegetable and fruit consumption and avoidance of foods containing highly refined sugars were shown to be negatively correlated to the risk of colon cancer (Giovannucci and Willett, 1994). Dietary Fiber There is some evidence based on observational and case-control studies that fiber-rich diets are protective against colorectal cancer (Lanza, 1990; Trock et al. There is also some epidemiological evidence of a pro- tective effect of cereals and cereal fiber against colon carcinogenesis (Hill, 1997). Despite these and other positive findings, a number of important studies (Fuchs et al. High-fiber diets may also be protective against the development of colonic adenomas (Giovannucci et al. However, not all studies have found a significant association between the dietary intake of total, cereal, or vegetable fiber and colorectal adenomas, although a slight reduction in risk was observed with increasing intake of fruit fiber (Platz et al. There are numerous hypotheses as to how fiber might protect against the development of colon cancer. These include the dilution of carcino- gens, procarcinogens, and tumor promoters in a bulky stool; a more rapid rate of transit through the colon with high-fiber diets; a reduction in the ratio of secondary bile acids to primary bile acids by acidifying colonic contents; the production of butyrate from the fermentation of dietary fiber by the colonic microflora; and the reduction of ammonia, which is known to be toxic to cells (Harris and Ferguson, 1993; Jacobs, 1986; Klurfeld, 1992; Van Munster and Nagengast, 1993; Visek, 1978). Recent studies have shown a decreased risk of endome- trial cancer (Barbone et al. Although fiber has the ability to decrease blood estrogen concentra- tions by a variety of different mechanisms (Rose et al. Half of the epidemiological studies attempting to link low dietary fiber intake to breast cancer have failed to show this relationship (Gerber, 1998). The data on cereal intake and breast cancer risk are considerably stronger than overall fiber intake (Rohan et al. Physical Activity Regular exercise, as recommended in this report, has been shown to be negatively correlated with the risk of colon cancer (Colbert et al. This is, in part, due to the reduction in obesity, which is positively related to cancer (Carroll, 1998). In men and women who are physically active, the risk of colon cancer is reduced by 30 to 40 percent compared with those who are sedentary. However, relatively few studies found a consistent association between physical activity and decreased incidence of endome- trial cancer. For prostate cancer, results of about 20 studies were less consistent, with only moderately strong relationships. With regard to the possible effect of exercise on other forms of cancer, such as pancreatic cancer (Michaud et al.

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Bulletin of the World Health Organization cheap zenegra 100 mg line erectile dysfunction hernia, 2002 cheap zenegra generic erectile dysfunction drugs in bangladesh, of Continuing Education in the Health Professions buy generic zenegra from india erectile dysfunction 50, 2004, 79:954–962. Effectiveness and costs of interventions Implementation and quantitative evaluation of chronic disease to lower systolic blood pressure and cholesterol: a global and self-management programme in Shanghai, China: randomized regional analysis on reduction of cardiovascular-disease risk. Hypertension management in a community-based rehabilitation in Punjab, Pakistan: I: Russian polyclinic. Therapy-based rehabilitation services for stroke patients at chronically ill seniors. Review: exercise-based cardiac rehabilitation reduces all- cause and cardiac mortality in coronary heart disease. The impact of different models of specialist palliative care on patients’ quality of life: a systematic literature review. Patient and carer preference for, and satisfaction with, specialist models of palliative care: a systematic literature review. Uganda: initiating a government public health approach to pain relief and palliative care. The opportunity exists to make a major contribution to the prevention and control of chronic diseases, and to achieve the global goal for chronic disease prevention and control by 2015. Each country has its own set of health functions at national and sub-national levels. While there cannot be a single prescription for implementation, there are core policy functions that should be undertaken at the national level. A national unifying framework will ensure that actions at all levels are linked and mutually supportive. Other government departments, the private sector, civil society and international organizations all have crucial roles to play. The a combination of interventions for the whole population and for individuals guidance and recommen- » Most countries will not have the resources dations provided in this immediately to do everything that would ideally be done. Those activities which are most chapter may be used by feasible given the existing context should be implemented first: this is the approach national as well as sub- » Because major determinants of the chronic national level policy- disease burden lie outside the health sector, action is necessary at all stages of makers and planners. Implementation step 3 Evidence-based interventions which are beyond the reach of existing resources. The first planning step is to assess the current risk factor profile of the population. The third planning step is to identify the most effective means of implementing this policy. The chosen combination of interventions can be considered as levers for putting policy into practice with maximum effect. Planning is followed by a series of implementation steps: core, expanded and desirable. The chosen combination of interventions for core implementation forms the starting point and the foundation for further action. These are not prescriptive, because each country must consider a range of factors in deciding the package of interventions that constitute the first, core implementation step, including the capacity for implementation, acceptability and political support. The reality is that public health action is incremental and opportunistic, reversing and changing directions constantly. The different planning and implementation steps might in fact overlap with one another depending on the unique situation. The priority accorded to different health programmes is partly a result of the broader political climate. It is important to identify, and ideally predict, the national or sub-national political climate and to capitalize on opportunities. The priorities of individual political leaders can be dramatically shaped by private experiences. There are many examples of leaders who, after being personally touched by disease, have subsequently made that disease a new national priority for action. This information predicts the future burden of disease; it must then be synthesized and disseminated in a way that successfully argues the case for the adoption of relevant policies. Although most countries have the resources for collecting data in the first two stages, the third is resource-intensive and not suited for all settings or sites. More than 300 key stake- media features, which influence the views of the holders from ministries of health, nongovernmental general public (including, where relevant, voters) organizations, medical and professional associations, as well as policy-makers directly; and international agencies participated. The workshops were structured to help build alliances identification and engagement of community between national governments and other stakeholders leaders and other influential members of society and to create a forum for the exchange of technical who can spread the message in different forums; information. Through meetings with ministers of health, joint planning and technical cooperation agendas have been established, and in the Caribbean Caucus of Ministers of Health a strategic plan was presented and adopted for a sub- regional approach to screening and treatment. It is accom- For many years the scale of the chronic disease problem in panied by plans and programmes that provide Indonesia had been concealed by a lack of reliable infor- the means for implementing the policy. Prevention and control activities were scattered, fragmented and lacked coordination. Periodic household The main goals of a public health policy for chronic disease prevention and control are similar to those of surveys later revealed that the proportion of deaths from any health policy: chronic diseases doubled between 1980 and 2001 (from 25% to 49%). The economic implications and the press- improve the health of the population, especially the most disadvantaged; ing need to establish an integrated prevention platform at respond to needs and expectations of people who national, district and community levels became clear. Indonesia’s Ministry of Health initiated a broad con- sultative process that resulted in a national consensus In all countries, a national policy and planning frame- work is essential to give chronic diseases appropriate on chronic disease policy and strategy. The document recom- action; mends targeting major diseases that share common risk intersectoral action; factors through surveillance, health promotion, prevention a life course perspective; and reform of health services. The need for integrated, stepwise implementation based on local considerations and needs. It is expected to be applicable to both the medium and it is both impossible and unnecessary to have specific programmes long term, and include an action plan for different chronic diseases; without a national organizing framework, there is a risk that for 3–5 years. This follows an earlier initiatives may be developed or implemented independently of each Programme of Cancer Prevention and other, and opportunities for synergies may not be realized. These include poverty, lack of education provide accessible and affordable health and unhealthy environmental conditions. It includes the development of risks, such as unhealthy diets and physical inactivity, are also influenced a national system of prevention and con- by sectors outside health, such as transport, agriculture and trade. At the financing, multisectoral cooperation and national level, it should be convened by the ministry of health, but with the establishment of expert committees representation from other relevant ministries and organizations. It will Different sectors may have different and sometimes even conflicting also involve capacity building and the priorities. In such situations, the health sector needs the capacity to establishment of a national surveillance provide leadership, to provide arguments for a win-win situation and to system, as well as periodic surveys of adapt to the agendas and priorities of other sectors. Adoles- health inequalities and increasing magnitude of chronic cents who have already adopted risk behaviours diseases in Chile. Based on this information, the Govern- such as tobacco use, or who have intermediate ment of Chile made a commitment to improving the health risks such as obesity, should be targeted for spe- of the population and to improving health among the most cialized interventions.

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It is very easy to obtain (and delete) images with digital fluoroscopy systems buy zenegra 100mg erectile dysfunction joliet, and there may be a tendency to obtain more images than necessary buy zenegra with paypal erectile dysfunction pump for sale. In digital radiology 100mg zenegra drinking causes erectile dysfunction, higher patient dose usually means improved image quality, so a tendency to use higher patient doses than necessary could occur. Different medical imaging tasks require different levels of image quality, and doses that have no additional benefit for the clinical purpose should be avoided. Image quality can be compromised by inappropriate levels of data compression and/or post-processing techniques. All of these new challenges should be part of the optimization process and should be included in clinical and technical protocols. Local diagnostic reference levels should be re-evaluated for digital imaging, and patient dose parameters should be displayed at the operator console. Training in the management of image quality and patient dose in digital radiology is necessary. Digital radiology will involve new regulations and invoke new challenges for practitioners. As digital images are easier to obtain and transmit, the justification criteria should be reinforced. Commissioning of digital systems should involve clinical specialists, medical physicists and radiographers to ensure that imaging capability and radiation dose management are integrated. The doses can often approach or exceed levels known with certainty to increase the probability of cancer. Proper justification of examinations, use of the appropriate technical parameters during examinations, proper quality control and application of diagnostic reference levels of dose, as appropriate, would all contribute to this end. All of these issues should be addressed for providing assistance in the successful management of patient dose. If the image quality is appropriately specified by the user, and suited to the clinical task, there will be a reduction in patient dose for most patients. Pregnancy and medical radiation Thousands of pregnant patients are exposed to radiation each year as a result of obstetrics procedures. Lack of knowledge is responsible for great anxiety and probably unnecessary termination of many pregnancies. Dealing with these problems continues to be a challenge primarily for physicians, but also for medical and health physicists, nurses, technologists and administrators. Medical professionals using radiation should be familiar with the effects of radiation on the embryo and foetus, including the risk of childhood cancer, at most diagnostic levels. Doses in excess of 100 ± 200 mGy risk nervous system abnormalities, malformations, growth retardation and fetal death. Justification of medical exposure of pregnant women poses a different benefit/risk situation to most other medical exposures, because in in utero medical exposures there are two different entities (the mother and the foetus) that must be considered. Prior to radiation exposure, female patients of childbearing age should be evaluated and an attempt made to determine who is or could be pregnant. For pregnant patients, the medical procedures should be tailored to reduce fetal dose. After medical procedures involving high doses of radiation have been performed on pregnant patients, fetal dose and potential fetal risk should be estimated. Pregnant medical radiation workers may work in a radiation environment as long as there is reasonable assurance that the fetal dose can be kept below 1 mGy during the course of pregnancy. Termination of pregnancy at fetal doses of less than 100 mGy is deemed to be unjustifiable, but at higher fetal doses, informed decisions should be made based upon individual circumstances. Radiological protection in paediatric diagnostic and interventional radiology Diagnostic radiological examinations carry a higher risk per unit of radiation dose for the development of cancer in infants and children compared to adults. The higher risk is due to the longer life expectancy of children, in which radiation effects could manifest, and the fact that developing organs and tissues are more sensitive to radiation. Risk is particularly high in infants and young children compared to older children. Justification of every examination involving ionizing radiation, followed by optimization of radiological protection is particularly important in every paediatric patient, in view of the higher risk of adverse effects per unit of radiation dose compared to adults. According to the justification principle, if a diagnostic imaging examination is indicated and justified, this implies that the risk to the patient of not performing the examination is greater than the risk of potential radiation induced harm to the patient. The implementation of quality criteria and regular audits should be instituted as part of the radiological protection culture in the institution. Imaging techniques that do not employ the use of ionizing radiation should always be considered as a possible alternative. For the purpose of minimizing radiation exposure, the criteria for the image quality necessary to achieve the diagnostic task in paediatric radiology may differ from adults, and noisier images, if sufficient for radiological diagnosis, should be accepted. The advice of medical physicists should be sought, if possible, to assist with installation, setting imaging protocols and optimization. Exposure parameters that control radiation dose should be carefully tailored for children and every examination should be optimized with regard to radiological protection. Apart from image quality, attention should also be paid to optimizing study quality. Acceptable quality also depends on the structure and organ being examined and the clinical indication for the study. Additional training in radiation protection is recommended for paediatric interventional procedures, which should be performed by experienced paediatric interventional staff due to the potential for high patient radiation dose exposure. Public protection: Release of patients after therapy with unsealed radionuclides A major concern for public protection related to medicine is the release of patients after therapy with unsealed radionuclides. After some therapeutic nuclear medicine procedures with unsealed radionuclides, precautions may be needed to limit doses to other people. Iodine-131 results in the largest dose to medical staff, the public, caregivers and relatives. Young children and infants, as well as visitors not engaged in direct care or comforting, should be treated as members of the public (i. The modes of exposure to other people are external exposure, internal exposure due to contamination, and environmental pathways. Contamination of infants and children with saliva from a patient could result in significant doses to the child’s thyroid. Many types of therapy with unsealed radionuclides are contraindicated in pregnant females. The second largest 131 discharges, I, can be detected in the environment after medical uses. Radionuclides released into modern sewage systems are likely to result in doses to sewer workers and the public that are well below public dose limits. The decision to hospitalize or release a patient should be determined on an individual basis. In addition to residual activity in the patient, the decision should take many other factors into account. Hospitalization will reduce exposure to the public and relatives, but will increase exposure to hospital staff. Hospitalization often involves a significant psychological burden as well as monetary and other costs that should be analysed and justified.

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In severe nephrotic syndrome with oedema cheap zenegra 100 mg visa erectile dysfunction doctors boise idaho, in- the tissues purchase discount zenegra online impotence only with wife, hydrogen ions compete with potassium to travenous albumin may be required together with di- be taken up by the cells order 100 mg zenegra visa erectile dysfunction hernia, so extracellular potassium con- uretics. As the acidosis is cor- rected, potassium is taken up by the cells and may cause Prognosis hypokalaemia. Conversely, in metabolic alkalosis potas- Acute severe symptomatic hyponatraemia has a mortal- sium is excreted in exchange for hydrogen ions, leading ityashighas50%. Chapter 1: Fluid and electrolyte balance 7 Insulin and activation of β2 receptors tend to drive may be a cardiac arrhythmia or sudden cardiac arrest. Investigations Hyperkalaemia U&Es, calcium, magnesium to look for evidence of renal Definition impairment and any associated abnormality in sodium, Aserumpotassiumlevelof>5. An arterial blood gas to look for aci- cardiac arrhythmias and sudden death without warning. This is a common problem, affecting as many as 1 in 10 Abnormalities occur in the following order: tall, tented inpatients. Patients may develop bradycardia or complete Aetiology heartblock,andifleftuntreatedmaydiefromventricular The causes are given in Table 1. Hyperkalaemia lowers the resting potential, shortens the cardiac action potential and speeds up repolarisation, Management therefore predisposing to cardiac arrhythmias. The ra- Ideally hyperkalaemia should be prevented in at-risk pa- pidity of onset of hyperkalaemia often influences the risk tientsbyregularmonitoringofserumlevelsandcarewith of cardiac arrhythmias, such that patients with a chron- medication and intravenous supplements. Once hyper- ically high potassium level are asymptomatic at much kalaemia is diagnosed, withdraw any potassium supple- greater levels. Foods high in muscle weakness or the potassium level is >7 mmol/L, potassium include bananas, citrus fruits, tomatoes and it is a medical emergency: salt substitutes. Thesecanberepeated transfusion of Rhabdomyolysis inhibitors whilst the underlying cause is addressed, but have only stored blood Digoxin toxicity Addison’s disease atemporaryeffect. Oral ion-exchange resins or enemas 8 Chapter 1: Principles and practice of medicine and surgery may be used to increase gastrointestinal elimination of repolarisation. Alkalosis also tends to promote the movement of K+ into cells, Hypokalaemia worsening the effective hypokalaemia. Definition r Increased digoxin toxicity: Digoxin acts by inhibition Aserum potassium level of <3. Incidence Clinical features This is a very common problem, occurring in up to 20% Hypokalaemia is often asymptomatic even when se- of inpatients. Symptoms include skeletal muscle weak- Aetiology ness, muscle cramps, constipation, nausea or vomiting The most common cause is diuretics. Pathophysiology On examination the patient may be hypotensive and Hypokalaemia causes disturbance of neuromuscular there may be evidence of cardiac arrhythmias such as function by altering the resting potential and slowing bradycardia, tachycardia or ectopic beats. Decreased Transcellular Increased intake movement output Investigations Usually Alkalosis Renal losses: diuretics, Apart from checking the serum potassium, U&Es, cal- iatrogenic: Insulin low serum cium and magnesium should be sent to look for other lack of oral treatment magnesium, renal electrolyte abnormalities. Ventricular/atrial prema- Malnutrition Conn’s/Cushing’s ture contractions or fibrillation may be seen or torsades syndrome and 2◦ de pointes. Treat any life- Drugs: β agonists, threatening arrhythmias appropriately and give intra- steroids, theophylline venous potassium with continuous cardiac monitoring. Chapter 1: Fluid and electrolyte balance 9 The highest rate of administration of potassium recom- clinical examination as well as monitoring of serum elec- mended in severe hypokalaemia is 20 mmol/h: this is trolytes by serial blood tests. The administration of tients with mild-to-moderate hypokalaemia oral or in- wateralonewouldleadtowatermovingacrosscellmem- travenous potassium supplements are given. The serum branes by osmosis, such that the cells would swell up and potassium must be rechecked frequently, e. Itshouldberememberedthatdextroseisrapidly Intravenous fluids metabolised by the liver; hence giving dextrose solu- Intravenous fluids may be necessary for rapid fluid re- tion is the equivalent of giving water to the extra- placement, e. If insufficient sodium is in patients who are unable to eat and drink or who giveninconjunction, or the kidneys do not excrete the are unable to maintain adequate intake in the face of free water, hyponatraemia results. When prescribing in- problem, often because of inappropriate use of dex- travenous fluids certain points should be remembered: trose or dextrosaline and because stress from trauma r Are intravenous fluids the best form of fluid replace- or surgery as well as diseases such as cardiac failure ment? For example, containhigh-molecular-weightcomponentsthattend blood loss should be replaced with a blood transfusion to be retained in the intravascular compartment. Additional potassium replacement is sure) of the circulation and draws fluid back into the often needed in bowel obstruction, but may be dan- vascular compartment from the extracellular space. There has been no consistent drugs or intravenous nutritional supplements (total demonstrable benefit of using colloid over crystalloid parenteral nutrition). Inaddition,theuseofalbumin r Patients at risk of cardiac failure (elderly, cardiac solution in hypoalbuminaemic patients (which seems disease, liver or renal impairment) require special logical)hasbeenassociatedwithincreasedpulmonary caution as they are more prone to develop fluid oedema,possiblyduetorapidhaemodynamicchanges overload. The Fluid regimens: These should consist of maintenance choice of fluid given and the rate of administration fluids (which covers normal urinary, stool and insensible depend on the patient, any continued losses and all losses) and replacement fluids for additional losses and patients must have continued assessment of their fluid to correct any pre-existing dehydration. Fluid regimens balance using fluid balance charts, observations and must also take into account that patients of differing 10 Chapter 1: Principles and practice of medicine and surgery Table1. Bothhypokalaemiaandhyper- blood as shown by the equation and so acutely com- kalaemia (see page 7) are potentially life-threatening and pensates for acidosis. The kidney is able to potassium is dangerous, so even in hypokalaemia no compensate for this, by increasing its reabsorption of more than 10 mmol/h is recommended (except in se- bicarbonate in the proximal tubule. The pH is first examined to see if the patient is acidotic or Atypical daily maintenance regime for a 70 kg man with alkalotic. The base In general, dextrosaline is not suitable for mainte- excess is defined as the amount of H+ ions that would be nance, as it provides insufficient sodium and tends requiredtoreturnthepHofthebloodto7. Replacement fluids base excess signifies a metabolic alkalosis (hydrogen ions generally need to be 0. In chronic respiratory be remembered that intravenous fluids do not provide acidosis renal reabsorption of bicarbonate will reduce any significant nutrition. Normally r Acidosiswithlowbicarbonateandnegativebaseexcess hydrogen (H+)ions are buffered by two main systems: defines a metabolic acidosis. If the patient is able the r Proteins including haemoglobin comprise a fixed respiration will increase to reduce carbon dioxide and buffering system. Causes of metabolic aci- Pathophysiology dosisincludesalicylatepoisoning(seepage528),lactic Hypercalcaemia prevents membrane depolarisation acidosis or diabetic ketoacidosis (see page 460). Al- leadingtocentralnervoussystemeffects,decreasedmus- ternatively failure to excrete acid or increased loss of cle power and reduced gut mobility. Hyperkalaemia may occur as an im- rate;itcan cause acute or chronic renal failure; it can also portant complication (see page 7) particularly if there causenephrogenicdiabetesinsipidus(seepage445),uri- is also acute renal failure. This may result from any cause of hyperven- ening of the Q–T interval but this is not associated with tilation including stroke, subarachnoid haemorrhage, an increased risk of cardiac arrhythmias. Early symptoms be caused by loss of acid from the gastrointestinal are often insidious, including loss of appetite, fatigue, tract (e. Hypokalaemia may occur toms of hypercalcaemia can be summarised as bones, (see page 8). Deposition of calcium in heart valves, coronary Aetiology arteries and other blood vessels may occur. Hyper- Important causes of hypercalcaemia are given in tension is relatively common, possibly due to renal im- Table 1. More than 80% of cases are due to malignancy pairment and also related to calcium-induced vasocon- or primary hyperparathyroidism (see page 446). The serum calcium should be checked and r Bisphosphonates can be used, which inhibit bone corrected for serum albumin because only the ionised turnoverandthereforereduceserumcalcium.