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.

Determining optimal needle size for decompression of tension pneumothorax in children - a CT-based study.

BACKGROUND: For neonates and children requiring decompression of tension pneumothorax, specific recommendations for the choice of needle type and size are missing. The aim of this retrospective study was to determine optimal length and diameter of needles for decompression of tension pneumothorax in paediatric patients. METHODS: Utilizing computed tomography, we determined optimal length and diameter of needles to enable successful decompression and at the same time minimize risk of injury to intrathoracic structures and the intercostal vessels and nerve. Preexisting computed tomography scans of the chest were reviewed in children aged 0, 5 and 10 years. Chest wall thickness and width of the intercostal space were measured at the 4th intercostal space at the anterior axillary line (AAL) on both sides of the thorax. In each age group, three needles different in bore and length were evaluated regarding sufficient length for decompression and risk of injury to intrathoracic organs and the intercostal vessels and nerve. RESULTS: 197 CT-scans were reviewed, of which 58 were excluded, resulting in a study population of 139 children and 278 measurements. Width of the intercostal space was small at 4th ICS AAL (0 years: 0.44 ± 0.13 cm; 5 years: 0.78 ± 0.22 cm; 10 years: 1.12 ± 0.36 cm). The ratio of decompression failure to risk of injury at 4th ICS AAL was most favourable for a 22G/2.5 cm catheter in infants (Decompression failure: right: 2%, left: 4%, Risk of injury: right: 14%, left: 24%), a 22G/2.5 cm or a 20G/3.2 cm catheter in 5-year-old children (20G/3.2 cm: Decompression failure: right: 2.1%, left: 0%, Risk of injury: right: 2.1%, left: 17%) and a 18G/4.5 cm needle in 10-year-old children (Decompression failure: right: 9.5%, left: 9.5%, Risk of injury: right: 7.1%, left: 11.9%). CONCLUSIONS: In children aged 0, 5 and 10 years presenting with a tension pneumothorax, we recommend 22G/2.5 cm, 20G/3.2 cm and 18G/4.5 cm needles, respectively, for acute decompression.

Chest wall thickness and depth to vital structures in paediatric patients - implications for prehospital needle decompression of tension pneumothorax.

BACKGROUND: Recommendations regarding decompression of tension pneumothorax in small children are scarce and mainly transferred from the adult literature without existing evidence for the paediatric population. This CT-based study evaluates chest wall thickness, width of the intercostal space (ICS) and risk of injury to vital structures by needle decompression in children. METHODS: Chest wall thickness, width of the intercostal space and depth to vital structures were measured and evaluated at 2nd ICS midclavicular (MCL) line and 4th ICS anterior axillary line (AAL) on both sides of the thorax using computed tomography (CT) in 139 children in three different age groups (0, 5, 10 years). RESULTS: Width of the intercostal space was significantly smaller at the 4th ICS compared to the 2nd ICS in all age groups on both sides of the thorax. Chest wall thickness was marginally smaller at the 4th ICS compared to the 2nd ICS in infants and significantly smaller at 4th ICS in children aged 5 years and 10 years. Depth to vital structure for correct angle of needle entry was smaller at the 4th ICS in all age groups on both sides of the thorax. Incorrect angle of needle entry however is accompanied by a higher risk of injury at 2nd ICS. Furthermore, in some children aged 0 and 5 years, the heart or the thymus gland were found directly adjacent to the thoracic wall at 2nd ICS midclavicular line. CONCLUSION: Especially in small children risk of iatrogenic injury to vital structures by needle decompression is considerably high. The 4th ICS AAL offers a smaller chest wall thickness, but the width of the ICS is smaller and the risk of injury to the intercostal vessels and nerve is greater. Deviations from correct angle of entry however are accompanied by higher risk of injury to intrathoracic structures at the 2nd ICS. Furthermore, we found the heart and the thymus gland to be directly adjacent to the thoracic wall at the 2nd ICS MCL in a few children. From our point of view this puncture site can therefore not be recommended for decompression in small children. We therefore recommend 4th ICS AAL as the primary site of choice.