Conundrum in an asthma exacerbation

Area of Science:

• Pulmonology
• Critical Care Medicine
• Clinical Biochemistry

Background:

• Acute asthma exacerbations require prompt management, often involving bronchodilators like salbutamol.
• Differential diagnoses in severe asthma include conditions mimicking respiratory failure and sepsis.
• Lactic acidosis is a known complication in critical illness, but its specific association with salbutamol requires careful consideration.

Observation:

• A 66-year-old asthmatic presented with type 1 respiratory failure and compensated lactic acidosis.
• Initial treatment for asthma exacerbation and sepsis did not resolve the worsening lactic acidosis.
• Discontinuation of salbutamol therapy led to a decrease in serum lactate levels.

Findings:

• Salbutamol-induced lactic acidosis (SILA) was diagnosed as the cause of the patient's metabolic derangement.
• SILA is a distinct entity from lactaemia associated with septic shock or life-threatening asthma.
• Peak flow measurements were not utilized for assessing asthma severity or treatment response in this case.

Implications:

• Clinicians should consider SILA in asthmatic patients with unexplained lactic acidosis, especially during or after intensive salbutamol therapy.
• Distinguishing SILA from sepsis-related lactic acidosis is critical for appropriate patient management and avoiding unnecessary antibiotic escalation.
• This case underscores the importance of a comprehensive diagnostic approach, including reassessing medication effects, in managing complex respiratory conditions.