Hyperkalaemia

Introduction Incidence Consequences Diagnosis Interventions Key Points References

Introduction

Hyperkalaemia is a potentially life-threatening condition that is most commonly seen in born extremely prematurely or in infants with impaired renal function. In premature infants the serum usually reaches a peak at 24 hours of age and declines to normal values by 72 hours of age. Infants at risk of hyperkalaemia need to be recognised early, their serum potassium levels measured and treatment initiated promptly to avoid cardiac arrhythmias and death.

Incidence and risk factors

Risk factors for hyperkalaemia in the neonate include:

Extreme Prematurity (< 27 weeks gestation) Low systemic blood flow Acute renal failure (most commonly perinatal asphyxia) Chronic renal failure - multiple causes Haemolysis (eg T and Tk activation / incompatible ) Double volume transfusion / use of "old blood" (K+ rises after 4 days in stored blood) Sepsis

Hyperkalaemia is a well-recognised complication in the first 12-48 hours in very low infants1. Associations with hyperkalaemia in preterm infants have included intraventricular haemorrhage2, 3 and periventricular leucomalacia3. Many of these infants do not have evidence of impaired renal function such as oliguria or high creatinine levels1. Suggestions to account for this phenomenon include potassium shifts from the intracellular to extracellular phase3-5, oliguria (although non- oliguric hyperkalaemia is the usual situation1, 4), immaturity of the renal tubular mechanisms for potassium secretion6 and a reduced glomerular filtration rate 1, 2, 7.

A strong association has been found between low systemic blood flow and hyperkalaemia has been demonstrated in a cohort of 118 infants born < 30 weeks gestation in JSN8.

file:///Volumes/neonatal/HTML_pre2013/hyperk.html[13/01/14 11:04:21 AM] Consequences

Figure: Hyperkalaemia leads to tall peaked T waves, ventricular arrhythmias, widening of QRS then sine wave QRS complex (before cardiac arrest).

Reported mortality of infants with hyperkalaemia (K+ > 7.0 mmol/L) has ranged from 17-30% despite appropriate treatment9, 10, most secondary to cardiac arrhythmia or complications of prematurity.

Diagnosis

Infants at risk of hyperkalaemia should have early and regular serum potassium levels performed. Use only blood from an arterial line, arterial puncture or free-flowing venous specimen. Infants born < 27 weeks gestation should have the serum potassium followed at least 6 hourly from 12 to 48 hours of age. The blood gas analyzer provides a rapid estimation of serum potassium and identifies the with a rising serum potassium. Laboratory measurement should be performed at least 12 hourly for the first 48 hours. ECG changes include tall peaked T waves, ventricular arrhythmias, widening of QRS, then sine wave QRS complex (before cardiac arrest). Haemolysis commonly occurs in blood collected by heel-prick and this results in falsely high serum potassium. A high serum potassium level after the first few days of life from a

file:///Volumes/neonatal/HTML_pre2013/hyperk.html[13/01/14 11:04:21 AM] heel-prick in an infant with normal renal function (normal creatinine and urine output), no underlying renal tract pathology and no iatrogenic source of potassium is almost always a false result. Check with an appropriate specimen if still in doubt.

Prevention:

Avoid potassium in all infusions in the first day of life in infants born prematurely unless documented hypokalaemia and adequate renal function.

Treatment:

An abnormal ECG should be treated immediately with IV gluconate. If K+ > 7.0 mmol/L or infant has abnormal ECG, use /dextrose infusion as first line therapy. Insulin/dextrose infusion9 and Salbutamol 14, 15 are effective in treating most infants with early neonatal hyperkalaemia. Poor outcomes of infants who received Salbutamol in the largest neonatal series (7 / 10 deaths preclude recommending this as first line therapy in neonates.

Watch for hyperglycaemia and hypoglycaemia that potentially complicate Insulin/dextrose infusion9. Serum glucose level followed initially ½ to 1 hourly until stable and when weaning the infusion (insulin persists longer than dextrose). Salbutamol appears to be well tolerated by premature infants14. Its use should be restricted to second line treatment in addition to an Insulin/dextrose infusion. Infants should be monitored for excessive tachycardia and hyperglycaemia. polystyrene sulfonate (Resonium-A) is a slow acting ion exchange resin that is less effective than other measures11 and impaction or rectal perforation by the Resonium plug potentially complicates treatment12, 13. Consider using it in infants with persistent hyperkalaemia (eg with renal failure). The following table lists the stepwise progression for treatment of neonatal hyperkalaemia:

Table 1: Management of hyperkalaemia (Summary)

Please note that the prescription of the following infusions should be obtained using the drug calculation module in the baby's database record, or obtain details from our Unit's web based drug guideline for hyperkalaemia

In non-haemolysed blood, if potassium Management level:

Serum potassium ³ 6 mmol/L without ECG Monitor K+ 1-2 hourly using blood gas changes analyzer

Serum potassium ³ 7 mmol/L with normal 1st line: Glucose-insulin infusion ECG (0.15 U/kg/hour insulin in 25% dextrose given as an intravenous infusion). If K+ rise persists: Salbutamol infusion 4 microg/kg in 5mls water

file:///Volumes/neonatal/HTML_pre2013/hyperk.html[13/01/14 11:04:21 AM] over 20 minutes (repeat as necessary)

Arrhythmias are appearing Give immediately:

IV 10% calcium gluconate

If acidosis: give bicarbonate (4.2% NaHCO3 [ml] = weight [kg] x base deficit x 0.3)

Give calcium gluconate before bicarbonate DO NOT GIVE CALCIUM AND BICARBONATE THROUGH THE SAME LINE

AND

1st line: Glucose-insulin infusion (0.15 U/kg/hour insulin in 25% dextrose given as an intravenous infusion).

If K+ rise persists: Salbutamol infusion 4 m g/kg in 5mls water over 20 minutes (repeat as necessary)

Refractory hyperkalaemia Consider:

Use both insulin/dextrose and Salbutamol infusions Sodium resonium 1g/kg per rectum (up to 6 hourly as necessary) Red cell transfusion with washed packed red cells16 Consult paediatric renal physicians and consider dialysis

Keypoints

Key Points Level of Evidence

Monitor the serum potassium 6-12 hourly 8, 9 for the 1st 48 hours of infants born < 27 weeks gestation

Insulin/dextrose and Salbutamol are 9, 14, 15 effective at reducing serum potassium levels in most preterm infants with hyperkalaemia

file:///Volumes/neonatal/HTML_pre2013/hyperk.html[13/01/14 11:04:21 AM] Future research:

1. A trial of insulin/dextrose versus Salbutamol in extremely preterm infants is required before adopting Salbutamol as routine 1st line treatment.

References

1. Shaffer SG, Kilbride HW, Hayen LK, Meade VM, Warady BA. in very low birth weight infants. J Pediatr, 1992; 121(2): 275-9.

2. Brion LP, Schwartz GJ, Campbell D, Fleischman AR. Early hyperkalaemia in very low birthweight infants in the absence of oliguria. Arch Dis Child, 1989; 64(2): 270-2.

3. Shortland D, Trounce JQ, Levene MI. Hyperkalaemia, cardiac arrhythmias, and cerebral lesions in high risk neonates. Arch Dis Child, 1987; 62(11): 1139-43.

4. Sato K, Kondo T, Iwao H, Honda S, Ueda K. Internal potassium shift in premature infants: cause of nonoliguric hyperkalemia. J Pediatr, 1995; 126(1): 109-13.

5. Stefano JL, Norman ME, Morales MC, Goplerud JM, Mishra OP, Delivoria Papadopoulos M. Decreased erythrocyte Na+,K(+)-ATPase activity associated with cellular potassium loss in extremely low birth weight infants with nonoliguric hyperkalemia. J Pediatr, 1993; 122(2): 276- 84.

6. Gruskay J, Costarino AT, Polin RA, Baumgart S. Nonoliguric hyperkalemia in the premature infant weighing less than 1000 grams. J Pediatr, 1988; 113(2): 381-6.

7. Lorenz JM, Kleinman LI, Markarian K. Potassium metabolism in extremely low birth weight infants in the first week of life. J Pediatr, 1997; 131: 81-6.

8. Kluckow M, Evans N. Hypoperfusion, Hyperkalaemia and serum lactate in the Preterm infant. APS/SPR Conference 1998, Abstract No 1043.

9. Lui K, Thungappa U, Nair A, John E. Treatment with hypertonic dextrose and insulin in severe hyperkalaemia of immature infants. Acta Paediatr, 1992; 81(3): 213-6.

10. Leslie GI, Carman G, Arnold JD. Early neonatal hyperkalaemia in the extremely premature newborn infant. J Paediatr Child Health, 1990; 26(1): 58-61.

11. Malone TA. Glucose and insulin versus cation-exchange resin for the treatment of hyperkalemia in very low birth weight infants. J Pediatr. 1991; 118: 121-3.

12. Bennett LN, Myers TF, Lambert GH. Cecal perforation associated with sodium polystyrene sulfonate-sorbitol enemas in a 650 gram infant with hyperkalemia. Am J Perinatol. 1996; 13: 167-70.

13. Ohlsson A, Hosking M. Complications following oral administration of exchange resins in extremely low-birth-weight infants. Eur J Pediatr. 1987; 146: 571-4.

14. Greenough A, Emery-EF, Brooker R, Gamsu HR. Salbutamol infusion to treat neonatal hyperkalaemia. J Perinat Med. 1992; 20: 437-41.

file:///Volumes/neonatal/HTML_pre2013/hyperk.html[13/01/14 11:04:21 AM] 15. Dilmen U, Toppare M, Senses DA, Kaya IS. Salbutamol in the treatment of neonatal hyperkalemia. Biol Neonate. 1992; 62: 424-6.

16. Setzer ES, Ahmed F, Goldberg RN, Hellman RL, Moscoso P, Ferrer PL, Noto TA. Exchange transfusion using washed red blood cells reconstituted with fresh-frozen plasma for treatment of severe hyperkalemia in the neonate. J Pediatr. 1984; 104: 443-6.

Last Reviewed: February, 1999

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