Comparison of Laboratory Findings for Simple and Complex Febrile Seizures.

Febrile seizures (FS) are the most common convulsive disorder in childhood and are classified into simple and complex subtypes. Although blood tests are not routinely required, certain laboratory parameters may provide additional information for distinguishing these subtypes. We conducted a single-center retrospective study of 67 children, including 41 with simple FS and 26 with complex FS. Laboratory and clinical findings were compared between groups. Venous blood gas analysis revealed significant differences in pH (P = .039) and pCO2 (P = .042). The area under the receiver operating characteristic (ROC) curve was 0.825 for pH (threshold 7.432) and 0.817 for pCO2 (threshold 37.0 mm Hg). Seizure duration showed strong correlations with base excess (r = -0.85), pH (r = -0.77), ammonia (r = 0.76), and pCO2 (r = 0.74). These findings suggest that venous blood gas parameters are associated with seizure duration and may reflect seizure severity rather than independently distinguishing FS subtypes.