Approach to the patient with renal tubular acidosis

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1 Oxford Medicine Online You are looking at of 169 items for: ACE and inhibitors MED00910 Approach to the patient with renal tubular acidosis Stephen B. Walsh DOI: /med/ The renal tubular acidoses are a collection of syndromes characterized by defective urinary acidification. These syndromes have classically caused some confusion, and many opine that the widely used numerical system (type 1, 2) should be abandoned. We consider distal renal tubular acidosis and proximal renal tubular acidosis separately, and briefly cover hypoaldosteronism. Distal (Type 1) renal tubular acidosis is a syndrome of hypokalaemia, metabolic acidosis, kidney stones, nephrocalcinosis, and osteomalacia or rickets. It is caused by failure of the acid secreting ##-intercalated cells in the distal nephron. Proximal (Type 2) renal tubular acidosis is a syndrome of metabolic acidosis that is almost always accompanied by the Fanconi syndrome of glycosuria, phosphaturia, uricosuria, aminoaciduria, and low-molecular-weight proteinuria. It is caused by a failure of bicarbonate reabsorption by the proximal tubular cells. Type 3 or mixed renal tubular acidosis, as originally described, has vanished (or was originally incompletely described). It is sometimes used to describe a mutation of carbonic anhydrase II, which causes both proximal and distal renal tubular acidosis, as well as cerebral calcification and osteopetrosis. Type 4 or hypoaldosteronism is a syndrome of hyperkalaemia and mild metabolic acidosis. It is due to a lack of aldosterone or resistance to its action. Postural proteinuria (benign orthostatic proteinuria) Neil Turner DOI: /med/ Postural proteinuria, synonymous with the condition known as benign orthostatic proteinuria, describes increased levels of protein excretion associated with normalization first thing in the morning. It is usually diagnosed in children, for whom it is the most common explanation for proteinuria picked up incidentally on dipstick testing. In children, it generally resolves with age and is thought to have a benign long-term prognosis, with the caveat that numbers with very long follow-up times are few. It is also seen in teenagers but becomes much less common in early adulthood. Its aetiology is not well understood, although patients with pathological causes for proteinuria and patients with physiological Page 1 of 5

2 levels of total protein excretion have been shown to exhibit similar diurnal variation. Using currently published limits for daily protein excretion the diagnosis is common. Some examples have been attributed to nutcracker syndrome (compression of the left renal vein), although that is more commonly associated with macroscopic haematuria, and the association remains uncertain. The condition is best diagnosed by comparing first-inmorning urine samples paired with afternoon samples on several occasions. In childhood, if proteinuria levels are in the normal range in morning samples, and within moderately increased limits later in the day, probably no investigation beyond observation is required. Most will resolve; very few will evolve into serious renal disease. The simplest mode of long-term monitoring is to measure protein:creatinine or albumin:creatinine ratios in firstin-morning urine samples. Mitral valve surgery B Martin and M Barnard Print Publication Year: 2010 Published Online: Oct 2011 ISBN: eisbn: DOI: /med/ Introduction 398 Mitral regurgitation 400 Mitral stenosis (MS) 404 Mixed mitral valve disease 408 Practice points 409 Further reading 410 The mitral valve is the left ventricle and the left ventricle is the mitral valve. (Steve Bolling, personal communication) Consequently, repair rather than replacement is preferred wherever possible to minimize disrupting this relationship and compromising left ventricular function. Operative mortality and long-term outcome is much improved if this is achieved it is the standard of care... The patient with sclerodermasystemic sclerosis Bernadette Lynch and Aine Burns DOI: /med/ Scleroderma is tightness, thickening, and non-pitting induration of skin. Two forms of the skin disease are described. Limited cutaneous systemic sclerosis (lcssc) which occurs distal to the wrists (or ankles) and/or over the face and neck, often associated with longstanding Raynaud s phenomenon, and diffuse cutaneous systemic sclerosis (dcssc) where truncal as well as acral skin involvement occurs as well as tendon friction rubs. In this latter condition the onset of the skin changes occurs within 1 year of onset of Raynaud s phenomenon; however, the skin involvement may precede onset of vascular symptoms. Page 2 of 5

3 The skin manifestations are the outward manifestation of a systemic disease, systemic sclerosis. Lung, heart, and gut involvement are frequent. Scleroderma renal crisis, usually presenting as accelerated hypertension and acute kidney injury, is one of the most severe complications of this disease. Autoantibodies against RNA polymerase are associated with scleroderma renal crisis. It occurs in 12% of dcssc and 2% of lcssc patients (men and women) and carries a high morbidity and mortality although careful supportive care and blood pressure management using angiotensin converting enzyme inhibitors (ACEI) or angiotensin-ii receptor blockers have improved short-term outcomes. In general, beta blockers should be avoided in the early management. Approximately two-thirds of patients require dialysis, of these many recover enough function to come off dialysis. Higher blood pressure and younger age at presentation have a better prognosis. ACEIs should be continued even after dialysis is established as the latter increases the chance of late recovery. Average time to coming off dialysis is 11 months but recovery is uncommon after 24 months. After a crisis renal function continues to improve for several years. Metabolic and endocrine disorders in the perioperative period Robert Robinson, David Chadwick, and Leanne Hunt Print Publication Year: 2016 Published Online: Jul 2016 ISBN: eisbn: DOI: /med/ This chapter covers the common metabolic and endocrine conditions encountered in the perioperative period. These disorders present potentially serious risks to the surgical patient that can be prevented or ameliorated by appropriate management. Close cooperation between the surgeon, anaesthetist, and endocrine team is essential in avoiding harm by omission or under treatment with hormone replacement. This is particularly important for patients with type 1 diabetes where under or over treatment with insulin must be avoided and those with adrenal insufficiency who need significant increases in glucocorticoid therapy to cope with the stresses of surgery. Oxidative stress and its implications in chronic kidney disease Nosratola D. Vaziri DOI: /med/ Reactive oxygen species (ROS) are produced at low levels physiologically and their production conveys signals and has specific functions. Control mechanisms ensure that this does not cause damage. ROS are highly reactive and cytotoxic and are also deliberately produced by inflammatory cells (granulocytes, macrophages) to kill pathogens. If these chemicals are released inappropriately or excessively, or if control mechanisms are underfunctioning, bystander or unintended tissue damage may be caused. The concept of oxidative stress is based on the idea that in certain states, commonly inflammatory states, Page 3 of 5

4 release of oxygen radicals may be excessive, or control mechanisms weakened, so that tissue damage occurs. In CKD, both overproduction and diminished control may apply. No effective therapies acting via these pathways have been established so far though there remain some candidates. Balkan endemic nephropathy Milan Radovi# and Adalbert Schiller DOI: /med/ Balkan endemic nephropathy (BEN) is a chronic, slowly progressive tubulointerstitial nephritis, with familial clustering, occurring in several endemic rural regions in countries of the Balkan Peninsula. BEN is characterized by anaemia, tubular proteinuria, renal shrinkage, and slowly declining glomerular filtration rate (GFR). Up to one-third of patients may also develop upper urothelial tumours. The aetiology of BEN is unclear; chronic exposure to aristolochic acid and a polygenic predisposition are the most likely contributing factors. The major pathological characteristics of BEN are symmetrically shrunken, smoothshaped kidneys, with interstitial fibrosis, mild interstitial inflammation, and tubular atrophy. Diagnosis is usually based upon positive family history of BEN, past or current residence in endemic regions, tubular proteinuria, tubular dysfunctions (such as urine acidification defects, salt wasting, and impaired excretion of ammonia, uric acid, and phosphate), scant urinary sediment, bilateral and symmetrically reduced kidney size, accompanied by severe anaemia, disproportionate to the degree of GFR reduction. There is no specific therapy for BEN; patients should therefore be treated as all patients with chronic kidney disease, in general. The use of distant water supplies or moving to another residence area should be advised to affected families. Careful evaluation for urothelial cancers is mandatory in patients with haematuria. Renovascular disease B. Rigden Green and M. G. Wyatt Print Publication Year: 2016 Published Online: Aug 2016 ISBN: eisbn: DOI: /med/ Renovascular disease is a recognized cause of secondary hypertension. The two main causes of renal artery stenosis are atherosclerosis and fibromuscular dysplasia. Treatment of renovascular disease can result in improved blood pressure control and reduction in progression of renal failure. All patients with renovascular disease should be managed with risk factor modification and best medical treatment in the first instance. Subsequent therapeutic strategies include surgical and endovascular techniques, with the preferred modality being endovascular. These treatments should only be carried out in patients who have failed medical management and when hypertension or ischaemic nephropathy is due to renal artery stenosis. It should be noted that not all patients with hypertension Page 4 of 5

5 have a renovascular cause and not all patients with renovascular disease require treatment. Thus careful patient selection is essential to reduce unnecessarily exposing patients to the periprocedural risks involved in invasive treatment. Renal and urological Joanna Chikwe, Axel Walther, and Philip Jones Print Publication Year: 2009 Published Online: Oct 2011 ISBN: eisbn: DOI: /med/ Acute renal dysfunction/failure 212 Oliguria 214 Urinary retention 216 Haematuria 218 Chronic renal failure 220 Dialysis patients 224 Nephrotic syndrome 226 Hyponatraemia 228 Hypernatraemia 230 Hypokalaemia 232 Hyperkalaemia 234 Hypercalcaemia 236 Hypocalcaemia 238 Magnesium and phosphate 240 #K+ >6.0mmol/L needs urgent treatment (... Chronic graft dysfunction Nicholas Torpey, Nadeem E. Moghal, Evelyn Watson, and David Talbot (eds) Print Publication Year: 2010 Published Online: Oct 2011 ISBN: eisbn: DOI: /med/ Causes of chronic graft dysfunction 258 Evaluation 260 Renal biopsy and histology 262 Management of CAN and CNI toxicity 264 CNI minimization and withdrawal 266 CNI conversion to SRL 268 True chronic rejection 270 BK virus nephropathy 272 Recurrent renal disease 276 Recurrent FSGS Page 5 of 5