In this study, we used clinical data from 96 PRS infants who underwent intubation anesthesia for correlation analysis which demonstrated that throat area had significant effect on tracheal intubation difficulty. The larger the throat area, the lower the level of tracheal intubation difficulty, which is consistent with clinician's subjective perception. In addition, we found that high BSA and weight corresponded to low tracheal intubation difficulty, which may be due to better physical development of such infants. Moreover, male infants had a higher tracheal intubation difficulty than females. Pneumonia, age, and height indicated low correlation with the difficulty of tracheal intubation, which may be related to the small amount of data collected and is worthy of further analysis.
After further P-value analysis, we found that four factors, namely throat area, gender, weight and BSA, were internally different under difficulty of tracheal intubation. Among them, the difference in throat area was significant between all levels of tracheal intubation difficulty. Gender, weight, and BSA were only significantly different between level Ⅱ and level Ⅲ, level Ⅰ and level Ⅲ. We speculate that it may be because the sample size of level Ⅰ tracheal intubation difficulty is too small. In addition, there were no statistically significance in height, age, pneumonia under tracheal intubation difficulty, which may be related to the small sample size, or because there is in fact no statistical significance.
Attention should be paid to some of the limitations of our research. First, we studied the correlation between risk factors and tracheal intubation difficulty without building a predictive model, because the limited number of cases obtained in this study could not meet the requirements for modelling. Secondly, in order to facilitate the drawing of the correlation coefficient map, the correlation measure was based on the Spearman rank correlation coefficient. In addition, the data for this study is single-centered. Finally, the annotation of the region of interest in the throat is done by one experienced doctor, which may be subjectively biased.
Based on the above limitations, following studies can be carried out in the future. First, further study may expand the number of cases collected and construct a predictive model of intubation difficulty. Secondly, regional annotation can be performed by multiple physicians, and artificial intelligence annotation tools can be constructed. Finally, the integration of labeling and difficulty prediction can be realized.