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Accuracy of predictive equations in guiding tracheal intubation depth in children: A prospective study
Puneet Khanna1, Heena Garg1, Bikash Ranjan Ray1
1Department of Anaesthesiology, Pain Medicine and Critical Care, All India Institute of Medical Sciences, New Delhi, India.
Insights
Middle finger length and age-based formulas accurately predict endotracheal tube (ETT) depth in children aged 1-4 years. These methods offer improved accuracy compared to weight or height for ETT placement in pediatric patients.
Area of Science:
- Pediatric Anesthesiology
- Airway Management
- Clinical Measurement
Background:
- Accurate endotracheal tube (ETT) insertion depth is crucial for pediatric airway management.
- Previous studies utilized demographic variables like age, weight, and height for ETT depth prediction.
- Middle finger length demonstrated a correlation with ETT depth in older children (4-14 years).
Purpose of the Study:
- To correlate actual ETT insertion depth with depths calculated from middle finger length, age, weight, and height formulas in children aged 1-4 years.
- To identify the most accurate formula for predicting ETT insertion depth in this pediatric age group.
Main Methods:
- Prospective study involving 50 children (ASA I-II) aged 1-4 years undergoing elective surgery.
- Measurements included age, weight, height, and middle finger length.
- ETT depth and tracheal length were measured using fiberoptic bronchoscopy; correlations with formula-derived depths were analyzed.
Main Results:
- Middle finger length and age-based formulas yielded the highest percentage of accurate ETT placements (58% each).
- Weight-based (74%) and height-based (64%) formulas resulted in a higher incidence of distal ETT misplacements.
- All tested formulas, including middle finger length, showed statistically significant correlations with actual ETT depth (p < 0.004).
Conclusions:
- Formulas derived from middle finger length and demographic variables correlate well with actual ETT depth in children aged 1-4 years.
- Middle finger length and age-based formulas provide superior accuracy for ETT depth prediction in this young pediatric population.
- These findings suggest that middle finger length can be a valuable tool for estimating ETT depth in young children.
Background:
Accurate insertion depth of endotracheal tube (ETT) in children has been predicted using the demographic variables, such as age, weight, and height. Middle finger length showed good correlation with ETT depth measurement in children aged 4-14 years.
Aims:
The primary objective was to correlate the actual ETT insertion depth with the depth derived from middle finger length, age, weight, and height formulae in children aged 1-4 years. The secondary objective was to find the most accurate formula for prediction of ETT insertion depth.
Methods:
This prospective parallel group study was done in 50 american society of anesthesiologists 1 or 2 children aged 1-4 years undergoing elective surgery under general anesthesia. Children with difficult airway, finger anomalies, or syndromic associations were excluded. Age, weight, height, and middle finger length of all children were measured. Depth of orally inserted uncuffed ETT and tracheal length was measured by fiberoptic bronchoscopy. The actual ETT depth was correlated with the depth calculated from different formulae.
Results:
The mean middle finger length was 4.42 ± 0.50 cm, age was 2.64 ± 1.07 years, weight was 12.28 ± 2.84 kg, and height was 82.89 ± 16.23 cm. The mean tracheal length was 6.42 ± 0.96 cm. The mean depth of ETT was actual depth (12.89 ± 1.09 cm), middle finger depth (13.23 ± 1.53cm; p = .001; 95%CI 0.12-0.50), age-based depth 1(3.31 ± 0.53 cm; 95%CI 0.37-1.44; p = .001), weight-based depth (14.14 ± 1.42 cm; 95% CI 0.10-0.51; p = .004), and height-based depth (13.73 ± 0.94 cm; 95% CI 0.15-0.77; p = .004). Middle finger length and age-based formulae showed higher number of accurate placements (58% each). Weight- (74%) and height (64%)-derived formulae gave a higher number of distal ETT placements.
Conclusion:
Formulas based on the demographic variables and middle finger length showed good correlation with the actual ETT depth in children aged 1-4 years. The percentage of accurate ETT depth placements was higher with middle finger length and age-based formulae.
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