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.
| Pharmacology | |
| Sodium Bicarbonate | |
| Dose | 0.5-1 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 bicarbonateà Alkalization agentà K+ Channel upregulationà↑ Excretion of K+ |
| Dilution | Volume expansion leads to less K+ per liter |
Jlpruitt@gmh.edu For educational purposes only
| Overview of Evidence | |||
| Author, year | Design/ sample size | Intervention & Comparison | Outcome |
| Ngugi, 1997 | Case Series n=10 | Insulin- 10 unit + glucose 25g ________________________________ 8.4% SB- 50 ml over 15 mins ________________________________ Salmeterol- 0.5 mg IV Combination of each | SB led to an average ↓ 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 | 8.4% SB-120 mEq/L x 1 hr ________________________________ Insulin drip- 0.5 unit/kg/min x 1 hr | SB led to ↑ of serum bicarbonate but no change in serum K+ (6.4 mEq/L to 6.3 mEq/L) Insulin drip led to ↓ of serum K+ (6.3 mEq/L to 5.7 mEq/L) Combination of insulin drip + SB led to ↓ in serum K+ (6.2 mEq/L to 5.2 mEq/L) |
| Blumberg, 1992 | Observational n=12 | 8.4% SB (240 mEq/hr) x 1hr then with 1.4% SB (30 mEq /hr) x 5 hrs | No change in K+ at hour 1 or 2 ↓ 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 | Observational n=18 | 1.4% SB in H2O (1mEq/kg) over 2 hrs ________________________________ 8.4% SB(1mEq/kg) over 5 mins | Isotonic SB led to ↑ in bicarbonate by 3 mEq/L and ↓ K+ by 0.35 mEq/L at 180 min Hypertonic SB led to slight ↑ in bicarbonate and Osmolality and not change in K+ levels |
| Blumberg, 1988 | Observational n=10 | 8.4% SB drip x 1 hr ________________________________ 1.4% SB drip x 1 hr ________________________________ Epinephrine drip 0.05 mcg/kg/min x 1 hr ________________________________ Insulin drip 0.5 unit/kg/min x 1 hr | Hypertonic and isotonic IV SB = ↑plasma bicarbonate and pH, but no impact on K+(5.66 versus 5.83 mEq/L) before vs after |
| Fraley, 1977 | Observational n=14 | SB 89-134 mEq/1000ml D5W over 4-6 hours ________________________________ D5W 1000ml over 4-6 hours | In SB infusion group, serum K+ ↓ by about 0.15 mEq/L for every 1 mEq/L ↑ in bicarbonate D5W was not effective in reducing potassium levels |
| Schwarz, 1959 | Case Series N=4 | 5% SB drip over 2-6 hours | Resolution of EKG abnormalities in all patients; 2/4 died within 24 hours |
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]
