Pre and posthydration in chronic kidney disease
Introduction
In coronary angiography and PCI, contrast fluids are used. The most common type of contrast fluid used is fluid containing iodine. Iodine can cause contrast induced nephropathy, an acute deterioration in kidney function(> 25% or > 44 micromol/l elevation of creatinine) 2 to 5 days after intravascular fluid administration[1].
Prevention
For prevention of contrast nefropathy, in the Netherlands the guideline issued by the CBO is used[2]. It advised for patients with eGFR < 45 ml/min to hydrate periprocedural. In patients with eGFR < 60 ml/min in combination with risk factors for nephropathy are also advised to hydrate. Risk factors are mentioned in table 1.
Hydration schemes
Hydration in people with normal cardiac function is done by prehydration with 0.9% NaCl 3-4 ml/kg/hr in 4 hours and posthydration with the same scheme (table 2). In patients with cardiac dysfunction the hydration is spread out over 12 hours (in stead of 4 hours) or the fast scheme with sodium bicarbonate (NaHCO3) can be used.
| Table 1: risk factors for contrast nephropathy |
|---|
| Diabetes mellitus |
| Peripheral arterial disease |
| Decompensatio cordis |
| Age > 75 years |
| Anemia |
| Symptomatic hypotension |
| High volume contrast fluid |
| Dehydration |
| Medication: diuretics, NSAID’s |
| Table 2: indications for pre- and posthydration | |
|---|---|
| eGFR < 45 ml / min | + diabetes mellitus |
| eGFR < 60 ml / min | + 2 risk factors (table 1) |
| eGFR < 60 ml/min | + M. Kahler or M. Waldenstrom with excretion of light chains urine |
| eGFR any | + earlier contrast nephropathy |
| Table 3: schemes for pre- posthydration | |
|---|---|
| Normal | 0.9% NaCl 0.9% 3-4 ml/kg/hr 4 hours pre- and postprocedural |
| Slow | 0.9% NaCl 0.9% 3-4 ml/kg/hr 4 hours pre- and postprocedural |
| Fast | 1.4% NaHCO3 3 ml/kg/hr 1 hour preprocedural and 6 hours postprocedural |