Chest Wall Thickness Research Articles

Prehospital Trauma Compendium: Traumatic Pneumothorax Care – a position statement and resource document of NAEMSP

ABSTRACT Emergency Medical Services (EMS) clinicians manage patients with traumatic pneumothoraces. These may be simple pneumothoraces that are less clinically impactful, or tension pneumothoraces that disturb perfusion, lead to shock, and impart significant risk for morbidity and mortality. Needle thoracostomy is the most common EMS treatment of tension pneumothorax, but despite the potentially life-saving value of needle thoracostomy, reports indicate frequent misapplication of the procedure as well as low rates of successful decompression. This has led some to question the value of prehospital needle thoracostomy and has prompted consideration of alternative approaches to management (e.g., simple thoracostomy, tube thoracostomy). EMS clinicians must determine when pleural decompression is indicated and optimize the safety and effectiveness of the procedure. Further, there is also ambiguity regarding EMS management of open pneumothoraces. To provide evidence-based guidance on the management of traumatic pneumothoraces in the EMS setting, NAEMSP performed a structured literature review and developed the following recommendations supported by the evidence summarized in the accompanying resource document. NAEMSP recommends: EMS identification of a tension pneumothorax must be guided by a combination of risk factors and physical findings, which may be augmented by diagnostic technologies. EMS clinicians should recognize the differences in the clinical presentation of a tension pneumothorax in spontaneously breathing patients and in patients receiving positive pressure ventilation. EMS clinicians should not perform pleural decompression in patients with simple pneumothoraces but should perform pleural decompression in patients with tension pneumothorax, if within the clinician’s scope of practice. When within scope of practice, EMS clinicians should use needle thoracostomy as the primary strategy for pleural decompression of tension pneumothorax in most cases. EMS clinicians should take a patient-individualized approach to performing needle thoracostomy, influenced by factors known to impact chest wall thickness and risk for iatrogenic injury. Simple thoracostomy and tube thoracostomy may be used by highly trained EMS clinicians in select clinical settings with appropriate medical oversight and quality assurance. EMS systems must investigate and adopt strategies to confirm successful pleural decompression at the time thoracostomy is performed. Pleural decompression should be performed for patients with traumatic out-of-hospital circulatory arrest (TOHCA) if there are clinical signs of tension pneumothorax or suspicion thereof due to significant thoraco-abdominal trauma. Empiric bilateral decompression, however, is not routinely indicated in the absence of such findings. EMS clinicians should not routinely perform pleural decompression of suspected or confirmed simple pneumothorax prior to air-medical transport in most situations. EMS clinicians may consider placement of a vented chest seal in spontaneously breathing patients with open pneumothoraces. In patients receiving positive pressure ventilation who have open pneumothoraces, chest seals may be harmful and are not recommended. EMS physicians play an important role in developing curricula and leading quality management programs to both ensure that EMS clinicians are properly trained in the recognition and management of tension pneumothorax and to ensure that interventions for tension pneumothorax are performed appropriately, safely, and effectively.

Residual breast tissue after mastectomy and reconstruction: A substudy of the Spatial location of breast cancer local rECurRence aftEr masTectomy (SECRET) project

The current project is part of the Spatial location of breast cancer local rECurRence aftEr masTectomy (SECRET) study (NCT06130111). Herein we compared the chest wall thickness after non-skin sparing mastectomy (non-SSM) with the chest wall thickness after SSM, as a surrogate for residual breast tissue after mastectomy. MethodsThe study was approved by the ethics committee of relevant institutions. Data of patients with a local recurrence (LR) after non-SSM was collected from the Netherlands Cancer Registry (NCR); data of patients undergoing SSM were collected from Sheba Medical Center. Student's t-test was used to evaluate the difference between the cohorts. Chest wall thickness was measured on postoperative images. ResultsOut of 4949 patients who underwent mastectomy from the NCR cohort, a total of 173 (3.5 %) had a LR at 5 years, of these a total of 153 patients included in the non-SSM cohort. The median age was 59 years (age 33–92), LR occurred at a median of 23.6 months (2.5–60 months). The SSM cohort included 84 patients, with a median age of 38.4 years (28–63.5), overall, 5 LRs occurred at a median of 15 months (5–46 months). The SSM cohort had significantly thicker chest walls compared to non-SSM (p < 0.001). Most LRs in both groups occurred in the subcutis. ConclusionThe chest wall thickness differed according to mastectomy procedures. Most of the LR occurred at the subcutis. The role of residual breast tissue and residual cancer in relation to type of mastectomy should be further investigated.

Evaluation of the accuracy of heart dose prediction by machine learning for selecting patients not requiring deep inspiration breath‑hold radiotherapy after breast cancer surgery.

Increased heart dose during postoperative radiotherapy (RT) for left-sided breast cancer (BC) can cause cardiac injury, which can decrease patient survival. The deep inspiration breath-hold technique (DIBH) is becoming increasingly common for reducing the mean heart dose (MHD) in patients with left-sided BC. However, treatment planning and DIBH for RT are laborious, time-consuming and costly for patients and RT staff. In addition, the proportion of patients with left BC with low MHD is considerably higher among Asian women, mainly due to their smaller breast volume compared with that in Western countries. The present study aimed to determine the optimal machine learning (ML) model for predicting the MHD after RT to pre-select patients with low MHD who will not require DIBH prior to RT planning. In total, 562 patients with BC who received postoperative RT were randomly divided into the trainval (n=449) and external (n=113) test datasets for ML using Python (version 3.8). Imbalanced data were corrected using synthetic minority oversampling with Gaussian noise. Specifically, right-left, tumor site, chest wall thickness, irradiation method, body mass index and separation were the six explanatory variables used for ML, with four supervised ML algorithms used. Using the optimal value of hyperparameter tuning with root mean squared error (RMSE) as an indicator for the internal test data, the model yielding the best F2 score evaluation was selected for final validation using the external test data. The predictive ability of MHD for true MHD after RT was the highest among all algorithms for the deep neural network, with a RMSE of 77.4, F2 score of 0.80 and area under the curve-receiver operating characteristic of 0.88, for a cut-off value of 300 cGy. The present study suggested that ML can be used to pre-select female Asian patients with low MHD who do not require DIBH for the postoperative RT of BC.

Safety and Risk Factors of Needle Thoracentesis Decompression in Tension Pneumothorax in Patients over 75 Years Old.

There are very few professional recommendations or guidelines on the needle thoracentesis decompression (NTD) for the tension pneumothorax in the elderly. This study aimed to investigate the safety and risk factors of tension pneumothorax NTD in patients over 75 years old based on CT evaluation of the chest wall thickness (CWT). The retrospective study was conducted among 136 in-patients over 75 years old. The CWT and closest depth to vital structure of the second intercostal space at the midclavicular line (second ICS-MCL) and the fifth intercostal space at the midaxillary line (fifth ICS-MAL) were compared as well as the expected failure rates and the incidence of severe complications of different needles. We also analyzed the influence of age, sex, presence or absence of chronic obstructive pulmonary disease (COPD), and body mass index (BMI) on CWT. The CWT of the second ICS-MCL was smaller than the fifth ICS-MAL both on the left and the right side (P < 0.05). The success rate associated with a 7 cm needle was significantly higher than a 5 cm needle (P < 0.05), and the incidence of severe complications with a 7 cm needle was significantly less than an 8 cm needle (P < 0.05). The CWT of the second ICS-MCL was significantly correlated with age, sex, presence or absence of COPD, and BMI (P < 0.05), whereas the CWT of the fifth ICS-MAL was significantly correlated with sex and BMI (P < 0.05). The second ICS-MCL was recommended as the primary thoracentesis site and a 7 cm needle was advised as preferred needle length for the older patients. Factors such as age, sex, presence or absence of COPD, and BMI should be considered when choosing the appropriate needle length.

Adjuvant Radiation Treatment of Breast Cancer After Mastectomy: Advanced Algorithms and Partial Bolus Improve the Dose Calculation Accuracy in the Case of Thin-Chest-Wall Irradiation

The aim of this study was to examine measured and calculated dose distributions in a thin-chest-wall phantom and estimate the variations in the dose-volume histogram (DVH) parameters used in plan evaluation for patient geometries with chest-wall thicknesses <15 mm with and without bolus implementation. Measurements were made using thermoluminescent dosimeters in a chest-wall phantom. The Monte Carlo method, anisotropic analytical algorithm, and Acuros XB Eclipse algorithms were used to calculate dose distributions for clinical plans. DVH parameters for clinical target volume tumor (CTVT) and planning target volume (PTV) and mean doses were evaluated for 15 patients with a chest-wall thickness of 8 to 15 mm with and without partial bolus and for 10 patients with a chest-wall thickness of 20 to 25 mm without bolus. Measurements showed that the dose at a depth of 2 to 12 mm at the beam entrance and laterally was within 90% of the dose at 8 mm depth. Monte Carlo and Acuros XB calculations were well aligned with the experimental data, whereas the anisotropic analytical algorithm underestimated the beam entrance and lateral doses. The DVH parameters for the patients with a thin chest wall were sensitive to calculation algorithm, resolution, body structure definition, and patient geometry. The parameters CTVTV95%, CTVTD98%, and PTVD98% were much lower than the tolerance criteria. Partial bolus improved the values for all algorithms and decreased the variations due to patient geometry. Dose calculations for patients with a chest-wall thickness of 20 to 25 mm resulted in sufficient target coverage and low dependence on patient geometry and calculation algorithm without the use of bolus. Dose calculations using advanced algorithms and resolution <2 mm are recommended for patients with a thin chest wall. Specific DVH criteria or the implementation of partial bolus was needed to facilitate plan development and evaluation for this patient group.

Risk of Harm in Needle Decompression for Tension Pneumothorax.

Tension pneumothorax (TPX) is the third most common cause of preventable death in trauma. Needle decompression at the fifth intercostal space at anterior axillary line (5th ICS AAL) is recommended by Tactical Combat Casualty Care (TCCC) with an 83-mm needle catheter unit (NCU). We sought to determine the risk of cardiac injury at this site. Institutional data sets from two trauma centers were queried for 200 patients with CT chest. Inclusion criteria include body mass index of =30 and age 18-40 years. Measurements were taken at 2nd ICS mid clavicular line (MCL), 5th ICS AAL and distance from the skin to pericardium at 5th ICS AAL. Groups were compared using Mann-Whitney U and chi-squared tests. The median age was 27 years with median BMI of 23.8 kg/m2. The cohort was 69.5% male. Mean chest wall thickness at 2nd ICS MCL was 38-mm (interquartile range (IQR) 32-45). At 5th ICS AAL, the median chest wall thickness was 30-mm (IQR 21-40) and the distance from skin to pericardium was 66-mm (IQR 54-79). The distance from skin to pericardium for 75% of patients falls within the length of the recommended needle catheter unit (83-mm). The current TCCC recommendation to "hub" the 83mm needle catheter unit has potential risk of cardiac injury.

Electrocardiographic index in aortic root enlargements and ventricular hypertrophy with Phi-based chest-wall thickness derived measure

Introduction: In addition to left ventricular hypertrophy (LVH), dilated aortic root (DAo) is a risk factor for cardiovascular events. There is a ack of a practical index that considers both scenarios. Objective: To assess an electrocardiographic index in DAo and LVH considering echocardiographic guidelines and those values stemming from the chest wall thickness (CT). Methodology: The population was 631 patients, 236 hypertensives (HT) and 395 non-hypertensives (NHT), the diameter of the aortic root was based on the Phi number and a derived formula CT x 1.33 = Ao, using a cut-off &gt;15%.

Study of Linear Energy Transfer Effect on Rib Fracture in Breast Patients Receiving Pencil-Beam-Scanning Proton Therapy

<h3>Purpose/Objective(s)</h3> To study the linear energy transfer (LET) effect upon rib fracture (RF) in breast cancer patients treated with pencil-beam scanning proton therapy (PBS) using dose-linear energy transfer volume histogram (DLVH). <h3>Materials/Methods</h3> After IRB approval, we retrospectively identified RF cases detected after workup of chest wall pain or incidentally on imaging in breast cancer patients treated with PBS to the breast/chest wall and regional nodes from 2015-2020. Control patients were selected to match the RF patients 2:1 considering prescription dose, boost location, reconstruction status, laterality, chest wall thickness, and treatment year. For all plans, a chest wall was contoured, incorporating ribs and intercostal muscles within the 50% prescription isodose line. Both dose and LET were calculated using a planning tool dose engine. DLVH was generated for each patient, using dose and LET as the two axes. The DLVH index, <i>V</i>(<i>d, l</i>), defined as <i>V</i>(% for normalized volume or cc for absolute volume) of the structure with a dose of at least <i>d</i> Gy[RBE] and an LET of at least <i>l</i> keV/µm, was calculated for all combinations of <i>d</i> and <i>l</i>. Conditional logistic regression model was used to establish the relation of <i>V</i>(<i>d, l</i>) and the observed RF at each combination of <i>d</i> and <i>l</i>. The derived <i>p values</i> constitute a <i>p value</i> map in the 2D dose and LET plane. Concordance and its standard error (se) maps were generated to evaluate the performances for all DLVH indices. A correlation coefficient map was obtained to determine the correlation between the featured DLVH indices. <h3>Results</h3> Eight RF cases were identified, and 16 controls were matched. Of RF patients, seven were treated with post-mastectomy (PMRT) and one was treated with post-lumpectomy radiotherapy. Six RF patients treated with PMRT received a dose of 50 Gy[RBE] in 25 fractions to the chest wall and regional lymph nodes; of these, four received a simultaneous integrated boost (SIB) of 56.25 Gy[RBE] to the chest wall (n=2) or axillary nodes (n=2), and one received a sequential boost of 14 Gy[RBE] in 7 fractions to the chest wall. One RF patient that received PMRT was treated with 40.05 Gy[RBE] in fifteen fractions to the chest wall and regional lymphatics. The post-lumpectomy patient received 50 Gy[RBE] in 25 fractions to the whole breast and regional nodes with a SIB of 56.25 Gy[RBE] to the lumpectomy cavity. Two characteristics correlated with RF (<i>p</i><0.2): 1) Smaller <i>V</i>(50-54 Gy[RBE], 0-4.4keV/µm) of the RF patients with a maximum concordance of 0.813 (se 0.114); 2) Larger <i>V</i>(0-36 Gy[RBE], 5.2-6.8keV/µm) of the RF patients with a maximum concordance of 0.875 (se 0.119) compared with controls. These two features were independent from each other with a weak negative correlation (-0.185). <h3>Conclusion</h3> The increase of high LET in moderate dose regions of the chest wall from constraining the adjacent heart and lung dose during PBS treatment planning may result in increased risk of RF.

Using Ultrasound to Determine Optimal Location for Needle Decompression of Tension Pneumothorax: A Pilot Study

BackgroundChest injury can result in life-threatening complications like tension pneumothorax, in which rapid deterioration can occur without decompression. Traditionally, the second intercostal space (ICS) along the mid-clavicular line is taught as the site for decompression. However, this has been questioned due to high rates of treatment failure. The fifth ICS on the mid-axillary line (MAL) is hypothesized to have a shorter distance from skin to pleura based on recent studies. ObjectiveThe purpose of this study was to use point-of-care ultrasound (POCUS) to compare chest wall thickness at these two locations. The primary objective was to evaluate the distance from skin to pleura line at the second ICS along the mid-clavicular line and the fifth ICS along the MAL. Secondarily, we aimed to evaluate inter-rater reliability of the two assessments. MethodsThis was a single-center, observational, pilot study. POCUS was performed using a linear transducer. Measurements of skin to pleura line were obtained at the right second ICS and fifth ICS. These measurements were then repeated by a blinded second ultrasonographer. Intraclass correlations (ICCs) for each measurement site were calculated to determine the inter-rater reliability. ResultsNinety-three percent of volunteers had a smaller chest wall distance at the fifth ICS-MAL. The median distance at the second and fifth ICS was 2.28 cm and 1.80 cm. The ICC for second ICS was 0.75 (95% CI 0.54–0.87), and 0.90 for the fifth ICS (95% CI 0.81–0.95), both indicating good reliability. ConclusionsThe data support that patients have a smaller chest wall distance at the fifth ICS vs. the second ICS. We support performing needle decompression at the fifth ICS and believe POCUS can be used to determine the optimal location for decompression.

Clavicular Malignancies: A Borderline Surgical Management.

Nearly 1% of all bone cancers are primary clavicular tumors and because of their rarity, treating clinicians are unfamiliar with their diagnosis, classification, treatment options, and prognosis. In terms of preserving function and avoiding complications, clavicle reconstruction seems logical; however, further studies are needed to support this measure. Reconstruction techniques are difficult taking into account the anatomical structures surrounding the clavicle. When chest wall defects are present, a multidisciplinary team, including an orthopedist and thoracic and plastic surgeons, is of paramount importance for optimal surgical management. Malignant clavicle tumors may include primary and secondary malignancies and neighboring tumors with clavicular invasion. Surgical resection of complex thoracic tumors invading the clavicles can result in larger defects, requiring chest wall reconstruction, which is a substantial challenge for surgeons. Correct diagnosis with proper preoperative planning is essential for limiting complications. Post-resection reconstruction of the partial or total claviculectomy is important for several reasons, including maintaining the biomechanics of the scapular girdle, protecting the vessels and nerves, reducing pain, and maintaining the anatomical appearance of the shoulder. The chest wall resection and reconstruction techniques can involve either partial or full chest wall thickness, influencing the choice of reconstructive technique and materials. In the present paper, we aimed to synthesize the anatomical and physiopathological aspects and the small number of therapeutic surgical options that are currently available for these patients.

Effects of Tumor-Rib Distance and Dose-Dependent Rib Volume on Radiation-Induced Rib Fractures in Patients with Breast Cancer.

This study aimed to investigate the effects of tumor-rib distance and dose-dependent rib volume on radiation-induced rib fractures (RIRFs) in patients with breast cancer. We retrospectively included 510 women with breast cancer who underwent surgical resection with adjuvant radiotherapy. The tumor-rib distance was measured using preoperative computed tomography (CT) images. Postoperative chest wall thickness and dose-dependent rib volumes, which are absolute rib volumes receiving >20 Gy (V20), 30 Gy (V30), 40 Gy (V40), 45 Gy (V45), and 50 Gy (V50), were measured from the stimulation CT images for radiation treatment planning. We assessed the relationship of RIRF with tumor-rib distance, postoperative chest wall thickness, and dose-dependent rib volumes. Patients with high values of tumor-rib distance and postoperative chest wall thickness had significantly lower risks of RIRF than those with low values. Patients with high values of V20, V30, V40, V45, and V50 had significantly higher risks of RIRF than those with low values. In a multivariate analysis, tumor-rib distance and all five dose-dependent rib volumes, as well as osteoporosis and radiation field, were independent risk factors for RIRF. Tumor-rib distance and dose-dependent rib volume were independent risk factors for RIRF in patients with breast cancer.

Failure of First Attempt Needle Decompression in Tension Pneumothorax: Case Report

Tension pneumothorax can occur as a potentially life threatening complication of chest trauma. Tension pneumothorax is commonly treated with needle decompression, both the 2nd intercostal space in the midclavicular line and the 4th/5th intercostal space in the anterior axillary. A 45 years old man came to our emergency department after blunt injury of the chest presenting tension pneumothorax with unstable hemodynamic treated with needle decompression using 14 gauge (4.5 cm) cannula at 2nd intercostal space mid clavicular line, patient successfully recover and became hemodynamic stable, after 30 minutes of successful needle decompression patient experienced with recurrent tension pneumothorax. Several studies show the failure of needle decompression it may due to several factor such as chest wall thickness, cannula length, and location of the needle decompression. In this case the cannula may has insufficient length (4.5 cm) to pass through the full thickness of the patient’s chest wall at 2nd intercostal space mid clavicular line (ICS 2) and makes air leaks from the lung faster than it can escape through the cannula.

Safely Inserting Neonatal Chest Drains

Background: Inserting a chest drain for a left-sided neonatal pneumothorax carries a risk of penetrating the pericardium. We identified reference ranges for the chest wall thickness (CWT) and distance between the pericardium and parietal pleura to improve safety of chest tube insertion. Method: We prospectively measured the CWT using ultrasound in 20 neonates (body weight [BW] 640–2,700 g, age <10 days) at the usual site of puncture in the 4th and 5th intercostal space (ICS). Furthermore, we measured the minimal distance between the parietal pleura and the cardiac silhouette in 131 neonatal chest X-rays (birth weight, 420–4,930 g [divided into 11 weight groups]; age <10 days). Both data sets were transformed into weight-dependent percentiles (Ps). We considered the difference between the sum of P 2.5 for the CWT plus P 2.5 for pleura-heart distance minus P 97.5 for the CWT as a safe corridor for placing the tip of the needle. Results: At both ICSs, curves for the above metrics did not cross, indicating a narrow but safe corridor for each BW with at least 97.5% probability. This safety corridor was 4.6–5.2 mm wide for the 4th and 2.8–3.4 mm for the 5th ICS. Conclusion: These data offer a reference for left-sided chest drain insertion for BW <2,700 g, which may help to improve safety of the procedure.

Obesity Phenotypes and Electrocardiographic Characteristics in Physically Active Males: CHIEF Study.

Background: Metabolically unhealthy obesity (MUO) has been associated with surface electrocardiographic (ECG) left ventricular hypertrophy (LVH), left atrial enlargement (LAE), and inferior T wave inversions (TWI) in the middle- and old-aged populations. However, the relationship between obesity phenotypes and these ECG abnormalities in physically active young adults is yet to be determined.Methods: A total of 2,156 physically active military males aged 18–50 in Taiwan were analyzed. Obesity and metabolically unhealthy status were, respectively, defined as the body mass index ≥27 kg/m2 and the presence of metabolic syndrome based on the ATPIII criteria for Asian male adults. Four groups were classified as the metabolically healthy non-obesity (MHNO, n = 1,484), metabolically unhealthy non-obesity (MUNO, n = 86), metabolically healthy obesity (MHO, n = 376), and MUO (n = 210). ECG-LVH was based on the Sokolow–Lyon and Cornell voltage criteria, ECG-LAE was defined as a notched P wave ≥0.12 s in lead II or a notch of ≥0.04 s, and inferior TWI was defined as one negative T wave axis in limb leads II, III, or aVF. Physical performance was evaluated by time for a 3-km run. Multiple logistic regression analysis with adjustment for age, smoking, alcohol drinking, and physical performance was utilized to investigate the associations between obesity phenotypes and the ECG abnormalities.Results: As compared to MHNO, MUNO, MHO, and MUO were associated with lower risk of Sokolow–Lyon-based ECG-LVH [odds ratios (OR) and 95% confidence intervals: 0.80 (0.51–1.25), 0.46 (0.36–0.58), and 0.39 (0.28–0.53), respectively; p for trend <0.001], and with greater risk of ECG-LAE [OR: 0.87 (0.44–1.72), 2.34 (1.77–3.10), and 3.02 (2.13–4.28), respectively; p for trend <0.001] and inferior TWI [OR: 2.21 (0.74–6.58), 3.49 (1.97–6.19), and 4.52 (2.38–8.60), respectively; p for trend <0.001]. However, no associations between obesity phenotypes and Cornell-based ECG-LVH were found.Conclusion: In physically active young males, obesity was associated with higher risk of ECG-LAE and inferior TWI, whereas the risk between obesity and ECG-LVH might vary by the ECG criteria, possibly due to a high prevalence of exercise induced-LVH in military and greater chest wall thickness in obesity. The cardiovascular prognosis of ECG-LVH in physically active obese adults requires further study.

Needle decompression in tension pneumothorax: anterior or lateral approach?

Background: For tension pneumothorax, the UK recommendation is to use a 14 g, 5 cm cannula to decompress the chest. Advice around site selection differs between using the second intercostal space (ICS) mid-clavicular line or the fifth ICS near the mid-axillary line. The aim of this literature review is to determine the best approach for needle decompression using a standard 14 g, 5 cm cannula. Methods: A systematic search of multiple databases was conducted, using inclusion and exclusion criteria. Outcomes were tabulated to identify any trends between various criteria including success with a 5 cm cannula. Results: Thirty-one studies were found, of which four were included. Mean chest wall thickness was 35.8 mm at the anterior site and 39.7 mm at the lateral site. Overall success rates with a 5 cm catheter were on average 79.7% at the anterior and 80% at the lateral position. Conclusion: There is no significant difference in success between using the anterior or the lateral approach for needle decompression.

A-lines and B-lines in patients with acute heart failure.

Lung ultrasound (LUS) relies on detecting artefacts, including A-lines and B-lines, when assessing dyspnoeic patients. A-lines are horizontal artefacts and characterize normal lung, whereas multiple vertical B-lines are associated with increased lung density. We sought to assess the prevalence of A-lines and B-lines in patients with acute heart failure (AHF) and examine their clinical correlates and their relationship with outcomes. In a prospective cohort study of adults with AHF, eight-zone LUS and echocardiography were performed early during the hospitalization and pre-discharge at an imaging depth of 18 cm. A- and B-lines were analysed separately off-line, blinded to clinical and outcome data. Of 164 patients [median age 71 years, 61% men, mean ejection fraction (EF) 40%], the sum of A-lines at baseline ranged from 0 to 19 and B-line number from 0 to 36. One hundred and fifty-six patients (95%) had co-existing A-lines and B-lines at baseline. Lower body mass index and lower chest wall thickness were associated with a higher number of A-lines (P trend < 0.001 for both). In contrast to B-lines, there was no significant change in the number of A-lines from baseline to discharge (median 6 vs. 5, P = 0.80). While B-lines were associated with 90-day HF readmission or death, A-lines were not [HR 1.67, 95% confidence interval (CI) 1.11-2.51 vs. HR 0.97, 95% CI 0.65-1.43]. A-lines and B-lines on LUS co-exist in the vast majority of hospitalized patients with AHF. In contrast to B-lines, A-lines were not associated with adverse outcomes.

Prehospital Decompression of Pneumothorax: A Systematic Review of Recent Evidence.

Pneumothorax remains an important cause of preventable trauma death. The aim of this systematic review is to synthesize the recent evidence on the efficacy, patient outcomes, and adverse events of different chest decompression approaches relevant to the out-of-hospital setting. A comprehensive literature search was performed using five databases (from January 1, 2014 through June 15, 2020). To be considered eligible, studies required to report original data on decompression of suspected or proven traumatic pneumothorax and be considered relevant to the prehospital context. They also required to be conducted mostly on an adult population (expected more than ≥80% of the population ≥16 years old) of patients. Needle chest decompression (NCD), finger thoracostomy (FT), and tube thoracostomy were considered. No meta-analysis was performed. Level of evidence was assigned using the Harbour and Miller system. A total of 1,420 citations were obtained by the search strategy, of which 20 studies were included. Overall, the level of evidence was low. Eleven studies reported on the efficacy and patient outcomes following chest decompression. The most studied technique was NCD (n = 7), followed by FT (n = 5). Definitions of a successful chest decompression were heterogeneous. Subjective improvement following NCD ranged between 18% and 86% (n = 6). Successful FT was reported for between 9.7% and 32.0% of interventions following a traumatic cardiac arrest. Adverse events were infrequently reported. Nine studies presented only on anatomical measures with predicted failure and success. The mean anterior chest wall thickness (CWT) was larger than the lateral CWT in all studies except one. The predicted success rate of NCD ranged between 90% and 100% when using needle >7cm (n = 7) both for the lateral and anterior approaches. The reported risk of iatrogenic injuries was higher for the lateral approach, mostly on the left side because of the proximity with the heart. Based on observational studies with a low level of evidence, prehospital NCD should be performed using a needle >7cm length with either a lateral or anterior approach. While FT is an interesting diagnostic and therapeutic approach, evidence on the success rates and complications is limited. High-quality studies are required to determine the optimal chest decompression approach applicable in the out-of-hospital setting.

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

BackgroundEmergent 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.MethodsWe 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.ResultsOf 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).ConclusionsCorrelation 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

Die prähospitale Therapie eines Spannungspneumothorax bei Kindern – welche Entscheidungen treffen wir?

The preclinical treatment of atraumatic or spontaneous tension pneumothorax remains aparticular 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. 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. An online survey was conducted with 43questions 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. 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. 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 alarge amount of uncertainty about the right choice of technique and equipment arises from the challenge of decompressing atension pneumothorax in children and therefore further theoretical education and regular training are required for safe performance of the procedure.

Development of a 3-dimensional printed tube thoracostomy task trainer: An improved methodology

Introduction: Simulation-based training has become a popular tool for chest tube training, but existing training modalities face inherent limitations. Cadaveric and animal models are limited by access and cost, while commercial models are often too costly for widespread use. Hence, medical educators seek a new modality for simulation-based instruction. 3D printing has seen growing applications in medicine, owing to its advantages in recreating anatomical detail using readily available medical images. Methods: Anonymised computer tomography data of a patient’s thorax was processed using modelling software to create a printable model. Compared to a previous study, 3D printing was applied extensively to this task trainer. A mixture of fused deposition modelling and material jetting technology allowed us to introduce superior haptics while keeping costs low. Given material limitations, the chest wall thickness was reduced to preserve the ease of incision and dissection. Results: The complete thoracostomy task trainer costs approximately SGD$130 (or USD$97), which is significantly cheaper compared to the average commercial task trainer. It requires approximately 118 hours of print time. The complete task trainer simulates the consistencies of ribs, intercostal muscles and skin. Conclusion: By utilising multiple 3D printing technologies, this paper aims to outline an improved methodology to produce a 3D printed chest tube simulator. An accurate evaluation can only be carried out after we improve on the anatomical fidelity of this prototype. A 3D printed task trainer has great potential to provide sustainable simulation-based education in the future.