An Investigation About The Relationship Between Body Weight And Inner Diameter Of Tracheal Tube In Children Undergoing Cleft Palate Operation

Objective: Cleft palate is a common birth defect, it happens in the exit of the alimentary canal and the airway ,and affects the feeding, so that makes children to be innutrition and get lower weight than children who are normal ones. In the past, we usually chose the inner diameter(ID) of tracheal tube(TT) by the formula inner diameter (ID) in mm = (age in yr/4) +4.0 and clinical experience. For this kind of children, can we use the formula of the age to choose the ID of TT? The foreign scholar has reported that the body weight can be betaken to estimate the ID of TT of the children. Is the new formula of body weight more exact than the formula of age? The investigation is to discuss the relationship between body weight and ID of TT in children undergoing cleft palate operation, and try to find out the formula of body weight that can be used in the clinical work.Method : We choose the cases of the children undergoing cleft palate operation from January 2009 to June 2010 ( 262 children that include 172 boys and 90 girls). Age 1～12, mean age 4. Body weight 7～40kg. All the children don't have the disease about the head and neck without cleft palate and cleft lip and infection. Mallanpati I～II, Cormack-Lehane I～II.. Anaesthetic:midazolam 0.1 mg/kg, atracurium 0.5 mg/kg,fentanyl 3μg/kg,propofol 2.5 mg/kg. We use cuffed armored tracheal tube which is little air leak when we give positive airway pressure at 15～20 cmH2O.And then give air to the cuff by no leak cuff inflation. When the tube is large or small, change the tube until the tube is fit. Record the body weight,age and ID of TT. All children's ID of TT are recorded by X±s, calculate Pearson correlation coefficient,estimate the relationship between body weight and ID of TT and the relationship between age and ID of TT, then t test, estimate the parameter.Result: The pearson correlation coefficient between body weight and ID of TT r1=0.8455,t=25.53,P<0.001,and the formula of weight is y=2.6+0.1x. The pearson correlation coefficient between age and ID of TT r2=0.8436,t=19.87,P<0.001. The pearson correlation coefficient r1=0.8455 and r2=0.8436, we can know that the ID of TT and body weight have positive correlation ,so is the ID of TT and body weight.So that the body weight and age all can be betaken to estimate the ID of TT. Because r1>r2,we can know that the body weight can be more exact to estimate the ID of TT than the age.Conclusion: The body weight and age of cleft palate children both can be betaken to estimate the ID of TT, and to compare with the age, the body weight also is a good method to estimate the ID of TT.