Disease activity in rheumatoid arthritis as a predictor of difficult intubation?

Rheumatoid arthritis is a lifelong systemic disease that can affect any joint with a synovium. Managing intubation in patients with rheumatoid disease is a special challenge in these patients especially if specific joints, which play an important role during intubation, are affected. We aimed to investigate if there was a correlation between the activity and duration of the disease and the commonly used predictors of difficult intubation in rheumatoid arthritis.

Sixty-six patients with the diagnosis of rheumatoid arthritis and 60 control patients were included in the study. Patient characteristics were recorded. Body mass index, disease activity scores, Mallampati classification, sternomental distance, thyromental distance, inter-incisor distance and atlanto-occipital joint extension were measured for each patient. Every patient was asked to complete the Stanford Health Assessment Questionnaire (HAQ score). Disease activity score (DAS 28 score) including 28 joints was used to assess the activity of the disease. Correlation between the predictors of difficult intubation and activity was assessed and was compared with the control group.

Mallampati scores were higher (P = 0.000), sternomental distance (P = 0.005) and inter-incisor distance (P = 0.003) were shorter and also occlusal surfacetragus line angle were smaller in the rheumatoid arthritis group compared with controls (P = 0.000). We did not observe a correlation between the disease activity scores and the Mallampati score (P = 0.619), sternomental distance (P = 0.195), thyromental distance (P = 0.174), inter-incisor distance (P = 0.764), angle I (P = 0.372) and angle II (P = 0.609). There was no correlation between the HAQ score and the Mallampati score (P = 0.872), sternomental distance (P = 0.455), thyromental distance (P = 0.841), inter-incisor distance (P = 0.162), angle I (P = 0.768) and angle II (P = 0.287). There was no correlation between the duration of the disease and the Mallampati score (P = 0.619), sternomental distance (P = 0.505), thyromental distance (P = 0.426), inter-incisor distance (P = 0.813), angle I (P = 0.377) and angle II (P = 0.600).

Tests of disease activity and the duration of the disease were not found to be correlated with the predictors of difficult intubation in this study. Thus, performing the predictive tests for difficult intubation especially in patients with very low scores or short disease is recommended.