Comparison of Sodium Lactate Infusion and Carbon Dioxide Inhalation Panic Provocation Tests: A Meta-analysis.

BACKGROUND

Sodium lactate (NaL) infusion and carbon dioxide (CO2) inhalation are proven to provoke acute panic attacks (PAs) in patients with panic disorder (PD). A systematic literature search and meta-analysis were performed to compare the effect sizes of these methods.

METHODS

Odds ratios were calculated for each of the original studies and were pooled using the random-effects model.

RESULTS

Either NaL or CO2 provocations significantly increased the rates of PAs in individuals with PD compared to those in healthy controls. However, the effect size of NaL infusion (OR=25.13, 95% CI=15.48-40.80) was significantly greater than that of CO2 inhalation (OR=10.58, 95%CI=7.88-14.21).

CONCLUSION

The evidence for the efficacy of the two panic provocation tests is very strong. Yet, the results support the superiority of NaL infusion over CO2 inhalation challenge as a panic provocation test. Thus, lactate seems a much stronger stimulus than CO2 for the brain suffocation detector.