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Introduction

  • Sodium bicarbonate was previously recommended for hyperkalemia treatment and was once

    • considered a first-line agent for transcellular shift.

  • Studies evaluating the beneficial effects of sodium bicarbonate used an isotonic infusion commonly

    • ~ 150 mEq/ 1000ml

  • Hypertonic sodium bicarbonate or “amp of bicarb” has an osmolality of 2000 mOsm, about 7x higher

    • than plasma.

  • There’s controversy as to whether hypertonic sodium bicarbonate is beneficial for the acute

    • treatment of hyperkalemia due to modifications in mechanism of action.

Clinical Detail

    Sodium Bicarbonate

    Dose

  • 5-1 mEq/kg IV bolus

    • 50-250 mEq hr Infusion

    Administration

    • Hypertonic 8.4 % (50mEq/50 ml) Slow IV push over 3-5 minutes

    • Isotonic Infusion 1.4% (150 mEq/L): 150-500 ml/hr x 2-6 hours

    PK/PD

    Onset IV: 0.5-4 hours

    Duration IV: 4-6 hours

    Excretion: Urine (<1%)

    Adverse Effects

    Hypocalemia

    Injection site extravasation

    Intracellular acidosis (without adequate ventilation)

    Hypernatremia

    Hyperosmosis

    Shift O2 release by hemoglobin

    Compatibility

    Incompatible with Epinephrine, calcium chloride, calcium gluconate,

    Sodium Bicarbonate Proposed Mechanisms of Action

    Transcellular shift

    Indirect movement of potassium into cells via an H+/K+ exchange and

    HCO3-/K+ cotransport.

    Renal Excretion

    K+ channels in the distal nephron are down-regulated by acidosis and

    up-regulated by alkalosis,

  • Sodium bicarbonate Alkalization agent K+ Channel

    • upregulationincreased Excretion of K+

    Dilution

    Volume expansion leads to less K+ per liter

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Evidence

    Author, year

    Design/ sample

    size

    Intervention & Comparison

    Outcome

    Ngugi, 1997

    Case Series

    n=10

    Insulin- 10 unit + glucose 25g

    ________________________________

  • 4% SB- 50 ml over 15 mins

    • ________________________________

    Salmeterol- 0.5 mg IV

    Combination of each

    SB led to an average decreased in K+ by 0.5 mEq/L

    drop at 30 minutes

    Combination therapy with insulin/dextrose +

    Salmeterol was more effective than those with SB

    Kim,1996

    Observational

    n=12

  • 4% SB-120 mEq/L x 1 hr

    • ________________________________

    Insulin drip- 0.5 unit/kg/min x 1 hr

    SB led to increased of serum bicarbonate but no change in

    serum K+ (6.4 mEq/L to 6.3 mEq/L)

    Insulin drip led to decreased of serum K+ (6.3 mEq/L to 5.7

    mEq/L)

    Combination of insulin drip + SB led to decreased in serum K+

    (6.2 mEq/L to 5.2 mEq/L)

    Blumberg, 1992

    Observational

    n=12

  • 4% SB (240 mEq/hr) x 1hr then with
  • 4% SB (30 mEq /hr) x 5 hrs

    • No change in K+ at hour 1 or 2

    decreased in serum K+ by 0.6 and 0.74 mEq/L at hours 4 and

    6 respectively, of which approximately half was

    calculated to be due to ECF volume expansion

    Peak T-waves in the ECG of 7 patients disappeared

    after one hour only in one patient

    Gutierrez, 1991

Conclusions

    • Blumberg A et al. Am J Med. 1988 Oct;85(4):507-12. [PMID: 3052050]

    • Blumberg A et al. Kidney Int. 1992 Feb;41(2):369-74. [PMID: 1552710 ]

    • Kim et al. Nephron. 1996;72(3):476-82. [PMID: 8852501]

    • Ngugi NN et al. East Afr Med J. 1997 Aug;74(8):503-9. [PMID: 9487416]

    • Long B et al. J Emerg Med. 2018 Aug;55(2):192-205. [PMID: 29731287]

References

    • Sodium Bicarbonate. Micromedex [Electronic version].Greenwood Village, CO: Truven Health Analytics. Retrieved August 29, 2019, 2018,

    from http://www.micromedexsolutions.com/

    • Gutierrez R et al. Miner Electrolyte Metab. 1991;17(5):297-302. [PMID: 1668124]

    • Fraley DSet al. Kidney Int. 1977 Nov;12(5):354-60. [PMID: 24132]

    • Blumberg A et al. Am J Med. 1988 Oct;85(4):507-12. [PMID: 3052050]

    • Blumberg A et al. Kidney Int. 1992 Feb;41(2):369-74. [PMID: 1552710 ]

    • Kim et al. Nephron. 1996;72(3):476-82. [PMID: 8852501]

    • Ngugi NN et al. East Afr Med J. 1997 Aug;74(8):503-9. [PMID: 9487416]

    • Long B et al. J Emerg Med. 2018 Aug;55(2):192-205. [PMID: 29731287]

Tags:hyperkalemia sodium bicarbonate potassium acidosis

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