Preventive Treatment Strategies
Widmer MK, Malik J (eds): Patient Safety in Dialysis Access.
Contrib Nephrol. Basel, Karger, 2015, vol 184, pp 13-23
DOI: 10.1159/000365498
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Patients with Chronic Kidney Disease: Safety Aspects in the Preoperative Management
Marko Malovrh
Department of Nephrology, University Medical Center Ljubljana, Ljubljana, Slovenia
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Abstract
Chronic kidney disease (CKD) is a major public health problem worldwide. Early detection and treatment of CKD can often prevent or delay some of the negative outcomes of CKD. This chapter shows how treatment of hypertension, proteinuria and metabolic disorders slow down the deterioration of renal function. Irrespective of the mode of renal replacement therapy, maintaining the veins in the upper extremities is of vital importance. Below are suggestions on how to protect blood vessels of the upper limbs and when to start preparing for the construction of vascular access. In this chapter, it is also shown how necessary it is to conduct a clinical evaluation of the blood vessels, which is required before the start of vascular access management. The methodology of noninvasive evaluation of vessels by duplex sonography is also presented. This method is very useful, especially if the vessels are not clinically visible, as well as the information concerning the morphological and functional properties of blood vessels.
© 2015 S. Karger AG, Basel
Recommendations to Improve Patient Safety
• For patients with chronic kidney disease (CKD), overall recommendations are to delay progression of both kidney disease and its complications. Treatment of hypertension, proteinuria, dyslipidemia, calcium-phosphate regulation and anemia are the key elements.
• Patients with progressive CKD, especially when they require renal replacement therapy, have to have an education program which should include modification of lifestyle, medication management, selection of treatment modality and instructions for vein preservation and for vascular access.
• Before vascular access surgery, physical and noninvasive examination by duplex ultrasonography of vessels is mandatory.
Chronic Kidney Disease
Chronic kidney disease (CKD) is a major public health problem worldwide. Kidney failure is becoming increasingly common and is associated with poor health outcomes and high medical expenditures. CKD is kidney damage for 3 or more months, as defined by structural or functional abnormalities of the kidney, with or without decreased glomerular filtration rate (GFR), manifested by pathologic abnormalities or markers of kidney damage, including abnormalities in the composition of the blood or urine or abnormalities in imaging tests or GFR <60 ml/min/1.73 m2 for 3 months or more, with or without kidney damage. The classification of CKD stages is shown in table 1 [1].
Decreased kidney function is associated with complications of all organ systems. The major outcomes of CKD, regardless of the specific diagnosis (i.e. type of kidney disease), include progression to kidney failure, complications from decreased kidney function, and development of cardiovascular disease. Increasing evidence shows that early detection and treatment often can prevent or delay some of these adverse outcomes. Referral to a nephrologist depends on practice patterns, which are not uniform across health care system or geographic regions, even within countries. Most cases of nonprogressive CKD can be managed without referral to the nephrologist. One indication that is common to most guidelines is patients with severely decreased GFR (estimated GFR, eGFR, <30 ml/min/1.73 m2). There are fewer consensuses about referral for patients with higher eGFR. Nephrologists can assist primary care physicians and other specialists in the diagnosis and care of patients at all stages of CKD. This includes determination of the cause of CKD, recommendations for specific therapy, suggestions for treatments to slow progression in patients who have not responded to conventional therapies, identification and treatment for kidney disease-related complications and preparation for renal replacement therapy [2].
Patients with CKD should be evaluated to determine the following:
• Specific diagnosis (type of kidney disease)
• Comorbid conditions
• Disease severity (assessed by the level of kidney function)
• Complications (related to the level of kidney function)
• Risk for loss of kidney function
• Risk for development of cardiovascular disease
Table 1. Classification of CKD stages
Stage | Description | GFR, ml/min/1.73 m2 |
1 | Kidney damage with normal or increased GFR | ≥90 |
2 | Kidney damage with mildly decreased GFR | 60-89 |
3 | Moderately decreased GFR | 30-59 |
4 | Severely decreased GFR | 15-29 |
5 | Kidney failure | <15 (or dialysis) |
Treatment of patients with CKD includes the following:
• Therapy based on the specific diagnosis
• Evaluation and management of co morbid conditions
• Measures to:
– slow loss of kidney function
– prevent and treat cardiovascular disease
– prevent and treat complications of decreased kidney function
• Preparation for kidney failure and kidney replacement therapy
• Replacement of kidney function by dialysis or transplantation if signs and symptoms of uremia are present
Medical Management of Patients with CKD
Progression of CKD toward end-stage renal disease (ESRD) is common in CKD patients, and once significant impairment of renal function has occurred, it tends to progress irrespective of the underlying kidney disorder. There is clear evidence from clinical studies that hypertension and proteinuria are key players in the pathophysiology of CKD progression in humans.
Hypertension is an independent risk factor for renal failure progression. Aggressive blood pressure reduction has always been shown to protect the kidney from further damage. The use of antihypertensive agents with antiproteinuric properties is also important but does not supersede the need to reach goal blood pressure. Antagonists of the renin-angiotensin system, such as ACE inhibitors and, more recently, angiotensin II type I receptor blockers have become pharmacotherapeutics of first choice. They significantly reduce blood pressure as well as urinary protein excretion and have an excellent safety profile. In adults with diabetic or nondiabetic kidney disease, several randomized trials demonstrate a more effective reduction of proteinuria, usually by 30-40%, by ACE inhibitors compared with placebo and/or other antihypertensive agents. Because hypertension is a multifactorial disorder, monotherapy is often not effective in lowering blood pressure or reducing proteinuria to the target range. Target blood pressure should be <130/80 or <125/75 mm Hg at more than 1 g/day/ 1.73 m2 of proteinuria. It is generally recommended to administer these drugs, after confirming tolerability in a short run-in period, at their highest approved doses [4, 5].
Proteinuria is also a powerful independent risk factor for ESRD and overall mortality and is certainly predictive of the renal prognosis in adults with diabetic and nondiabetic kidney disorders. Reduction of proteinuria is associated with a slowing of GFR loss in the long term. Protein restriction may slow the progression of CKD, although the optimal level of protein intake has not been determined. The goal of any antiproteinuric treatment is to reduce proteinuria as much as possible, ideally to <300 mg/m2/day. Renin-angiotensin system antagonists preserve kidney function, not only by lowering blood pressure but also through antiproteinuric and antifibrotic properties [6].
A wide range of disorders may develop as a consequence of the loss of renal function. These include disorders of fluid and electrolyte balance, such as volume overload, hyperkalemia, metabolic acidosis, and hyperphosphatemia, as well as abnormalities related to hormonal or systemic dysfunction, such as anorexia, nausea, vomiting, fatigue, hypertension, anemia, malnutrition, hyperlipidemia, and bone disease.
Dyslipidemia is common in patients with renal disease. Lipid-lowering medical treatment is commonly prescribed in adults with CKD based on the evident benefit of this approach for primary and secondary prevention of cardiovascular disease in the general adult population. Statin therapy is effective in reducing cardiovascular morbidity and mortality in adults with moderate to severe CKD although not in patients with ESRD. With respect to renoprotection, experimental evidence suggests that statins may retard renal disease progression not only by their lipid-lowering but also by lipid-independent pleiotropic effects [7].
There is an increasing tendency to retain hydrogen ions among patients wit...