Clinical Picture

• 28-year-old woman presenting with shortness of breath
• Patient identifies presentation in keeping with previous acute asthma episodes, with a clear precipitant. 
• Effective inhaler use with shortness of breath now resolved. 
• Looks well, normal physical examination, no wheeze.

 

Findings

• Sample type: arterial
• Supplemental oxygen: no
• paO2: 91.7 mmHg
• paCO2: 36.1 mmHg
• pH: 7.43
• Bicarbonate (HCO3-): 23.9mEg/L
• Base excess: +1.4
• Acid-base balance: normal
• Other parameters: normal

 

Summary 

• All parameters were within normal limits on this blood gas.
• The low-normal paCO2, high-normal pH and normal base excess would be consistent with a mild or resolving acute respiratory alkalosis, such as that commonly found in acute asthma.

 

Further reading

• Blood gas interpretation guide