Impact of changes in head position during head and neck surgery on the depth of tracheal tube intubation in anesthetized children

A new formula based on height for determining endotracheal intubation depth in pediatrics: A prospective study

STUDY OBJECTIVE

The main objective was to devise an endotracheal intubation formula based on pediatric patients' strongly correlated growth parameters. The secondary objective was to compare the accuracy of the new formula to the age-based formula from Advanced Pediatric Life Support Course (APLS formula) and the middle finger length-based formula (MFL-based formula).

DESIGN

A prospective, observational study.

SETTING

Operation.

PATIENTS

111 subjects age 4-12 years old undergoing elective surgeries with general orotracheal anesthesia.

INTERVENTIONS AND MEASUREMENTS

Growth parameters, including age, gender, height, weight, BMI, middle finger length, nasal-tragus length, and sternum length, were measured before surgeries. Tracheal length and the optimal endotracheal intubation depth (D) were measured and calculated by Disposcope. Regression analysis were used to establish a new formula for predicting the intubation depth. A self-controlled paired design was used to compare the accuracy of the intubation depth between the new formula, APLS formula, and MFL-based formula.

MAIN RESULTS

Height (R = 0.897, P < 0.001) was strongly correlated to tracheal length and the endotracheal intubation depth in pediatric patients. New formulae basing on height were established, including new formula 1: D (cm) = 4 + 0.1 × Height (cm) and new formula 2: D (cm) = 3 + 0.1 × Height (cm). Via Bland-Altman analysis, the mean differences for new formula 1, new formula 2, APLS formula and MFL-based formula were - 0.354 cm (95% LOA, -1.289 to 1.998 cm), 1.354 cm (95% LOA, -0.289 to 2.998 cm), 1.154 cm (95% LOA, -1.002 to 3.311 cm), -0.619 cm (95% LOA, -2.960 to 1.723 cm), respectively. The rate of optimal intubation for new formula 1 (84.69%) was higher than for new formula 2 (55.86%), APLS formula (61.26%), and MFL-based formula. (69.37%).

CONCLUSIONS

The prediction accuracy for intubation depth of the new formula 1 was higher than the other formulae. The new formula based on height: D (cm) = 4 + 0.1 × Height (cm) was preferable to APLS formula and MFL-based formula with a high incidence of appropriate endotracheal tube position.

Tracheal Tube Misplacement after Emergency Intubation in Pediatric Trauma Patients: A Retrospective, Exploratory Study

Inadvertent tracheal tube misplacement and particularly endobronchial intubation are well-known complications of emergency endotracheal intubation (ETI) in pediatric trauma patients, which require repositioning of the tube to avoid impairment of gas exchange. The main aim of study was to identify the frequency of tube misplacement and associated factors of pediatric trauma patients who received ETI either by prehospital physician-staffed emergency medical service (EMS), or at emergency department (ED) admission to a single level-1 trauma center. Sixty-five patients (median age 14 years and median injury severity score 29) were included. Of these, 30 underwent helicopter EMS ETI, 29 ground EMS ETI, and 6 ED ETI. Seventeen cases (26%) of tracheal tube misplacement were recognized. After multivariable analysis, tracheal tube misplacement was independently negatively associated with body weight (OR 0.86; 95% CI, 0.76–0.99; p = 0.032) and helicopter EMS ETI (OR 0.20; 95% CI, 0.04–0.97; p = 0.036). Two of nineteen patients received tube thoracostomy due to endobronchial intubation. Mortality and length of stay were comparable in patients with misplaced tubes and correctly placed tubes. The results suggest that particularly small children require attention to avoid tracheal tube misplacement, which emphasizes the need for special training. Helicopter EMS physicians’ expertise might be beneficial in prehospital pediatric trauma patients requiring advanced airway management.

Effect of head position changes on the depth of tracheal intubation in pediatric patients: A prospective, observational study

PURPOSE

The purpose of this study was to investigate the effect of changing head position on the endotracheal tube (ETT) depth and to assess the risk of inadvertent extubation and bronchial intubation in pediatric patients.

METHODS

Subjects aged 4-12 years old with orotracheal intubation undergoing elective surgeries were enrolled. After induction, the distances between "the ETT tip and the trachea carina" (T-C) were measured using a Disposcope flexible endoscope in head neutral position, 45° extension and flexion, 60° right and left rotation. The distance of the ETT tip movement relative to the neutral position (ΔT-C) was calculated after changing the head positions. The direction of the ETT tip displacement and the adverse events including endobronchial intubation, accidental tracheal extubation, hoarseness and sore throat were recorded.

RESULTS

The ETT tip moved toward the carina by 0.5 ± 0.4 cm (P < 0.001) when the head was flexed. After extending the head, the ETT tip moved toward the vocal cord by 0.9 ± 0.4 cm (P < 0.001). Right rotation resulted that the ETT tip moved toward the vocal cord direction by 0.6 ± 0.4 cm (P < 0.001). Moreover, there was no displacement with the head on left rotation (P = 0.126). Subjects with the reinforced ETT had less ETT displacement after changing head position than the taper guard ETT.

CONCLUSION

The changes of head position can influence the depth of the ETT especially in head extension. We recommend using the reinforced ETT to reduce the ETT displacement in pediatrics to avoid intubation complications.

CLINICAL TRIAL REGISTRATION

[www.ClinicalTrials.gov], identifier, [ChiCTR2100042648].