SOMOS Annual meeting
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presents
Wheeless' Textbook of Orthopaedics

Fluids Electrolytes and Nutrition: in renal failure





- Acidosis consider HCO3, if hypoCa, then give IV Ca first;
    - limit protein intake w/ renal diet (organic acids);
    - non dietary   sources of a sudden increase in sodium intake
          include the administration of sodium bicarbonate or Shohl's
          solution in metabolic acidosis or the use of cation exchange
          resins for hyperkalemia;
    - although the detrimental effects of acidosis on bones are esp manifested in
          children, they may be a cause of renal osteodystrophy in adults;
    - administration of alkali therapy to minimize acidosis must,
          be weighed against the threat of volume overload;
    - hyperchloremia acidosis is not typical of renal failure;
          - its presence signals the existence of volume contraction;
    - antacids may also bind Fe & limit absorption from intestine;
    - harmful effects include nausea, vomit, & cerebral dysfunction, cardiac
          depression, insulin resistance, and impaired cellular metabolism;
    - acidosis will also contribute to hyperkalemia;
    - metabolic acidosis is treated w/ Shohl's solution, IV bicarbonate, or dialysis;
- Hyponatremia:
    - although the capacity to dilute urine becomes severly limited
          only at very low GFRs, pts with renal insufficiency are prone
          to hyponatremia from water retension if given a fluid load;
    - free water intake is exceeding free water elimination;
    - this occurs when administration of IV fluids is excessive and hyptonic
    - when hyponatremia begins to evolve, free water restriction must be
          prescribed;
    - if the serum sodium concentration falls below 120 mEq per liter,
          convulsions are immenent;
          - dialysis is the only maneuver that can correct the hyponatremia
              in this situation;
          - administration of hypertonic NaCl in the oliguric patient with
              severe hyponatremia is prohibited, because patient is almost
              always fluid overloaded;
- HyperPhos:
    - must be controlled as it promotes metastatic calcification and
          osteodystrophy; (keep Phos below < 5.0)
    - decr phospate may prevent calcium precipitation in tubules;
          - consider Phoslo or Amphogel;
    - avoid Fleet's enema
    - consider Ca acetate to bind phosphorous;
    - use of phosphate binding gels should be monitored, especially
          if a patient is on a low protein diet that will decrease
          production of nonvolatile acids;
          - combination may severely restrict the availability of
              urinary phosphate for titratable acid, and this could
              further limit net acid excretion;
- Renal diet:
    - dietary objective is to maintain the pt at a wt which will keep blood pressure in
          good control and renal function stable;
    - 4 gm salt diet will suffice for most patients;
            - if the wt rises then further reduction is necessary;
            - addition of lasix may permit a higher sodium diet;
    - restrict Na gradually;
            - diseased kidneys appear to waste salt, continuing to excrete Na to point
                  of dehydration & vascular collapse when Na intake is suddenly restricted;
            - when sodium intake is reduced gradually (4 to 14 wks), renal function can
                remain stable on a sodium intake as low as 5 mEq/day;
            - if dietary sodium intake is suddenly curtailed, excretion of Na will continue,
                & negative sodium balance, w/ volume contraction, decreased renal
                perfusion, & further reduction in GFR;
    - it is inappropriate to routinely restrict dietary sodium intake;
            - Na restriction should be reserved for pts with evidence of total body
                  sodium excess (CHF, Edema, HTN);




Original Text by Clifford R. Wheeless, III, MD.