Sound and Air: Ultrasonographic Measurements of Pediatric Chest Wall Thickness and Implications for Needle Decompression of Tension Pneumothorax

Sonographic assessment of pediatric chest wall thickness and width of the intercostal space: correlation with anthropometric data and implications for needle decompression

Background

Emergent needle decompression in children is a rare event for emergency medicine and critical care providers. Hereby, risk of injury of intrathoracic structures is high and knowledge of age-specific values of chest wall thickness and width of the intercostal space (ICS) is crucial to avoid injuries. Investigation of the correlation of chest wall thickness and width of the intercostal space with age and body dimension like weight and height could provide guidance on depth of insertion and choice of the needle.

Methods

We performed a prospective observational clinical trial in a pediatric surgery operating room that included a convenient sample of children aged 0–10 years undergoing elective surgery. Chest wall thickness and width of the intercostal space were measured with ultrasound at 2nd ICS midclavicular line (MCL) and 4th ICS anterior axillary line (AAL). Correlation of these measures with age, height, weight, BMI and Broselow color was calculated. Furthermore, intra-class correlation coefficient was calculated as a measure of reproducibility and the presence of vital structures (e.g., heart, thymus gland, large pulmonary vessels) at the possible insertion sites for needle decompression was investigated.

Results

Of 410 potentially eligible patients, 300 were included in the study. Correlation of chest wall thickness was moderate with weight (2nd ICS MCL: r = 0.57; 4th ICS MCL: r = 0.64) and BMI (r = 0.44 and r = 0.6) and was lower with age (r = 0.38 for both intercostal spaces), height (r = 0.42 and r = 0.40) and Broselow color (r = 0.42 and r = 0.38). Correlation of width of the ICS with anthropometric data was generally stronger, with height showing the strongest, albeit not really strong, correlation (r = 0.71 and r = 0.62). Intra-class correlation was excellent with an ICC of 0.93. Vital structures were significantly more often present at 2nd ICS MCL then at 4th ICS AAL (14 vs. 2 patients; p = 0.0042).

Conclusions

Correlation of chest wall thickness and width of the intercostal space with anthropometric data is at most moderate. Insertion depth and width of the intercostal space can therefore not be predicted accurately from anthropometric data. Ultrasound assessment of the thoracic wall appears to be a reliable technique and could therefore assist in reducing the risk of injury and increasing decompression success.

Trial registration German clinical trials register, DRKS00014973, Registered February 11th 2019, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00014973

Supplementary Information

The online version contains supplementary material available at 10.1186/s13089-021-00226-6.

[Prehospital treatment of tension pneumothorax in children-which decisions do we make? : Results of a survey among German emergency physicians]

BACKGROUND

The preclinical treatment of a traumatic or spontaneous tension pneumothorax remains a particular challenge in pediatric patients. Currently recommended interventions for decompression are either finger thoracostomy or needle decompression. Due to the tiny intercostal spaces, finger thoracostomy may not be feasible in small children and surgical preparation may be necessary. In needle decompression, the risk of injuring underlying vital structures is increased because of the smaller anatomic structures. As most emergency physicians do not regularly work in pediatric trauma care, decompression of tension pneumothorax is associated with significant uncertainty; however, in this rare emergency situation, consistent and goal-oriented action is mandatory and lifesaving. An assessment of pre-existing experience and commonly used techniques therefore seems necessary to deduce the need for future education and training.

OBJECTIVE

In this study an online survey was created to evaluate the experience and the favored prehospital treatment of tension pneumothorax in children among German emergency physicians.

MATERIAL AND METHODS

An online survey was conducted with 43 questions on previous experience with tension pneumothorax in children, favored decompression technique and anatomical structures in different age groups. Surveyed were the emergency physicians of the ground-based emergency medical service of the University Medical Center Mannheim, the German Air Rescue Service (DRF) and the pediatric emergency medical service of the City of Munich.

RESULTS

More than half of all respondents stated that there was uncertainty about the procedure of choice. Needle decompression was favored in smaller children and mini-thoracostomy in older children. In comparison with the literature, the thickness of the chest wall was mostly estimated correctly by the emergency medical physicians. The depth of the vital structures was underestimated at most of the possible insertion sites in all age groups. At the lateral insertion sites on the left hemithorax, however, the distance to the left ventricle was overestimated. The caliber of the needle selected for decompression tended to be too large, especially in younger children.

CONCLUSION

Even though having interviewed an experienced group of prehospital emergency physicians, the experience in decompression of tension pneumothorax in children is relatively scant. Knowledge of chest wall thickness and depth to vital structures is sufficient, the choice of needle calibers tends to be too large but still reasonable. For many providers a large amount of uncertainty about the right choice of technique and equipment arises from the challenge of decompressing a tension pneumothorax in children and therefore further theoretical education and regular training are required for safe performance of the procedure.