UMEM Educational Pearls

Respiratory alkalosis is the most common acid-base disturbance in acute severe asthma.


Lactic acidosis is also extremely common, developing in up to 40%. This may be related to:

- tissue hypoxia

- increased respiratory muscle usage related to work of breathing

- beta agonist therapy


The first report of beta agonist administration associated with hyperlactatemia was in 1981 in patients treated for preterm labor with terbutaline. Since then, numerous case reports and studies have linked IV and inhaled beta agonist administration with the development/worsening of lactic acidosis in severe asthmatics in the ICU and in the ED.


The exact mechanism is unclear, but is thought to be related to adrenergic stimulation leading to increased conversion of pyruvate to lactate.


In a study published in Chest in 2014, investigators evaluated plasma albuterol levels and serum lactate levels, as well as FEV1.

They found plasma albuterol levels correlated with lactate concentration and maintained significant association after adjusting for asthma severity (suggesting the association was independent of work of breathing/respiratory muscle usage).


Furthermore, several reports have suggested that dyspnea may improve in patients with elevated lactate and acidosis after beta agonists are withheld.



Take Home Points:

- Beta agonist therapy may contribute to lactic acidosis.

- Lactic acidosis may contribute to respiratory distress.

- In patients on prolonged, high-dose beta agonist therapy, consider checking a serum lactate periodically. If elevated, consider whether worsening lactic acidosis is contributing to respiratory distress and contemplate transitioning to less frequent treatments.

-Patients with severe asthma exacerbation and elevated serum lactate must have thorough evaluation for true tissue hypoxia/hypoperfusion. **Beta agonist associated hyperlactatemia should be a diagnosis of exclusion.**


Raimondi GA, Gonzalez S, Zaltsman J, Menga G, Adrogué HJ. Acid–base patterns in acute severe asthma. J Asthma. 2013;50(10):1062-1068. doi:10.3109/02770903.2013.834506.

Rabbat A, Laaban JP, Boussairi A, Rochemaure J. Hyperlactatemia during acute severe asthma. Intensive Care Med. 1998;24(4):304-312.

Rodrigo GJ, Rodrigo C. Elevated plasma lactate level associated with high dose inhaled albuterol therapy in acute severe asthma. Emerg Med J. 2005;22(6):404-408. doi:10.1136/emj.2003.012039.

Lewis LM, Ferguson I, House SL, et al. Albuterol Administration Is Commonly Associated With Increases in Serum Lactate in Patients With Asthma Treated for Acute Exacerbation of Asthma. Chest. 2014;145(1):53-59. doi:10.1378/chest.13-0930.

Koul PB, Minarik M, Totapally BR. Lactic acidosis in children with acute exacerbation of severe asthma. Eur J Emerg Med. 2007;14(1):56-58. doi:10.1097/