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Three Part Question

In [adults (>16 years) presenting to the emergency department with hyperkalaemia] is [nebulised salbutamol] effective at [lowering serum K+ levels]?

Clinical Scenario

A 50- year old woman is referred to the Emergency Department by her GP with a serum potassium level of 6.4 mmol/L. A repeat blood test confirms hyperkalaemia, with a serum potassium of 6.8 mmol/L. After giving a cardiac membrane stabiliser and an IV infusion of insulin and glucose her serum potassium is still high. You consider prescribing nebulised salbutamol but wonder how effective this would be at this stage.

Search Strategy

Cochrane Library for Systematic Reviews: May 2011
MEDLINE using OVID interface: 2003 to June week 2 2011
EMBASE: 2003 to 2011 week 24
Cumulative Index to Nursing and Allied Health Literature (CINAHL) Plus: 1947 to June 26th 2011
COCHRANE:hyperkalaemia, hyperkalemia, hyperkal*, hyperpotass*, potassium and hyperpotassaemia

MEDLINE: [exp Potassium/ OR exp Hyperkalemia/ OR hyperkalaemia.mp/ OR high potassium.mp/ OR hyperkal$.mp/ OR hyperpotass$.mp] AND [Salbutamol.mp/ OR exp Albuterol/ OR Adrenergic beta-agonist.mp/ OR exp Adrenergic beta-Agonists/ OR Ventolin.mp.] Limit to (english language and humans and yr="2003 -Current")

EMBASE: [exp Potassium/ OR exp Hyperkalemia/ OR hyperkalaemia.mp/ OR high potassium.mp/ OR hyperkal$.mp/ OR hyperpotass$.mp] AND [exp salbutamol/ or Salbutamol.mp./ OR albuterol. mp / OR Adrenergic beta-agonist.mp/ OR exp beta adrenergic receptor stimulating agent/ OR Ventolin.mp.] Limit to (english language and humans and yr="2003 -Current")

CINAHL: [Hyperkalaemia/ OR Hyperkalemia/ OR Potassium/ OR High Potassium/ OR Hyperkal*/ OR Hyperpotass*]AND [salbutamol/ OR albuterol/ OR ventolin/ OR adrenergic beta-agonist/ OR beta adrenergic receptor stimulating agent] Limit to (english language and humans)

Search Outcome

COCHRANE: 51 papers found, one of which is relevant. Paper dated to 2003.
MEDLINE: 77 papers found, 2 of which were relevant.
EMBASE:623 papers found, 1 of which was relevant.
CINAHL: 23 papers found, 2 of which were relevant.
After removing duplicates 3 papers were found, one of which was the Cochrane review. The 2 additional papers identified were included in the Cochrane review and were therefore not re-reviewed.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Mahoney BA, Smith WA, Lo D, Tsoi K, Tonelli M, Clase C 2005 Canada.	3 prospective double-blinded placebo controlled studies and 1 randomised prospective cross-over study.	Systematic review. 1a.	Serum potassium concentration.	Inhaled/nebulised salbutamol effective compared to placebo by 30 minutes and at all time points after that.	No additional data provided in the Cochrane Review.
				20 mg nebulised salbutamol more effective than 10mg. P < 0.05 at 120 mins.
				Salbutamol and levalbuterol equally effective at 30 and 60 minutes compared to placebo.
				Elevation of serum K+ by 0.1mmol/L in 59% of patients after 1 minute. Returned to baseline by 3 mins, then fell progressively reaching statistical significance compared to placebo at 5 - 10 mins.

Comment(s)

There is some high level evidence supporting the use of nebulised salbutamol in the emergency management of hyperkalaemia. From these studies it can be seen that nebulised salbutamol begins to reduce serum potassium levels within 3 minutes, with a significant reduction compared to baseline achieved by 30 minutes and maximal effects at 60 minutes. 10 mg albuterol has been shown to be comparable to 2.5mg levalbuterol, but less effective than 20mg albuterol. However, there are cases where patients appear to be resistant to the hypokalaemic effects of salbutamol and there are some reported associated adverse effects, including tremor and tachycardia. The majority of patients studied are those with renal failure and the sample sizes are small.

Clinical Bottom Line

Nebulised salbutamol is an effective treatment in the emergency management of hyperkalaemia.

References

1. Mahoney BA, Smith WA, Lo D, Tsoi K, Tonelli M, Clase C Emergency interventions for hyperkalaemia Cochrane Database of Systematic Reviews. 2005, Issue 2