Abdominal Compression Research Articles

Radiation Therapy (RT) Quality Assurance (QA) Analysis of Alliance A021501: Preoperative mFOLFIRINOX or mFOLFIRINOX plus Hypofractionated Radiation Therapy for Borderline Resectable Adenocarcinoma of the Pancreas (PDAC)

<h3>Purpose/Objective(s)</h3> Alliance A021501 is the first national clinical trial to test the efficacy of stereotactic body radiation therapy (SBRT) in patients with PDAC. Herein, we aim to (1) review metrics used to provide high quality RT; (2) assess reasons for protocol deviations; and (3) analyze potential inter-observer variability with respect to contouring. <h3>Materials/Methods</h3> Each site was required to undergo credentialing prior to RT through IROC Houston. A tutorial for RT contouring and planning was recommended. Patients received SBRT (6.6 Gyx5) (strongly preferred) or hypofractionated RT (5 Gyx5) (HIGRT). Compliance criteria was provided for the target volume coverage and organs-at-risk (OARs). All cases required pre-treatment review by an experienced radiation oncologist (RO, TJ). Fiducials and daily imaging were required. Unacceptable deviations from the protocol were resubmitted for review and revised until approved. Cases requiring revision were carefully analyzed. RT plans were independently graded by 3 ROs with respect to several QA parameters. <h3>Results</h3> 40 patients were registered to receive RT (1 case planned but not treated) at 27 centers by 34 ROs. 16 centers were academic, 9 community. Centers were credentialed for an average of 3 years prior to enrollment (range: 0-9). 11 centers (6 academic, 5 community) required at least 2 attempts to pass credentialing. 23 centers were approved for moving lung/liver targets and 4 for static head and neck only. 33 patients were treated with SBRT, 6 with HIGRT. 5 cases (13%) required revision prior to RT. 54% patients (n=21) were female with a median age of 67 years. Time from enrollment to the start of RT was on average 117 days. Target and OAR volume data is shown in the Table. Motion management involved abdominal compression (33%), free breathing with increased margin (23%), or gating (23%). A median of 3 fiducials per case were used (range: 1-5). Details related to on-treatment delivery and image guidance were not recorded. Any deviations related to contouring or RT plans will be correlated with toxicity and outcomes. <h3>Conclusion</h3> There were no major deviations in RT planning. Variations in contouring, image fusion, and the potential influence of dose/fractionation differences on outcomes will be presented at the meeting. The results of this study serve to inform subsequent PDAC SBRT trial design and QA requirements.

Results from the AAPM Task Group 324 respiratory motion management in radiation oncology survey.

To quantify the clinical practice of respiratory motion management in radiation oncology. A respiratory motion management survey was designed and conducted based on clinician survey guidelines. The survey was administered to American Association of Physicists in Medicine (AAPM) members on 17 August 2020 and closed on 13 September 2020. A total of 527 respondents completed the entire survey and 651 respondents completed part of the survey, with the partially completed surveys included in the analysis. Overall, 84% of survey respondents used deep inspiration breath hold for left-sided breast cancer. Overall, 83% of respondents perceived respiratory motion management for thoracic and abdominal cancer radiotherapy patients to be either very important or required. Overall, 95% of respondents used respiratory motion management for thoracic and abdominal sites, with 36% of respondents using respiratory motion management for at least 90% of thoracic and abdominal patients. The majority (60%) of respondents used the internal target volume method to treat thoracic and abdominal cancer patients, with 25% using breath hold or abdominal compression and 13% using gating or tracking. A respiratory motion management survey has been completed by AAPM members. Respiratory motion management is generally considered very important or required and is widely used for breast, thoracic, and abdominal cancer treatments.

Lung Tumor Motion and its Impact on Deep Learning Prediction of Local Recurrence

<h3>Purpose/Objective(s)</h3> In order for deep learning (DL) models to successfully predict local recurrence of lung tumors from image-based features, uncertainties of the model must be quantified. One potential source of uncertainty for the DL model is lung tumor motion. We aimed to evaluate the association of motion magnitude with the prediction accuracy of the DL model. We hypothesized that knowledge of motion will help quantify the uncertainties of prediction and guide the use of individualized risk predictions for lung radiotherapy. <h3>Materials/Methods</h3> Physician delineated gross tumor volume (GTV) of 19 patients were propagated to their corresponding 10 breathing phases of the 4DCT images using a commercial treatment planning system. A programming environment code was used to extract the contours and determine the centroid and volume bounded by the contours. Motion was determined from the displacement of the GTV centroid. The Euclidean distance was calculated and used as an aggregate measure of tumor motion magnitude. The 4DCT, free-breathing CT (FBCT) and maximum-intensity projection (MIP) images of the 18 patients were used as input to a pre-trained DL model. The 8-layer DL model was previously trained to predict local recurrence using FBCT images of 933 lung patients. Correlation between motion magnitude and prediction accuracy was calculated for 4DCT images in each respiratory phase, FBCT and MIP images. <h3>Results</h3> Tumor movement with a mean exertion of 1 cm [IQR: 0.72-1.53] was observed from the cohort with 47.4 % of patients subjected to abdominal compression, and 57.9% of patients had peripheral lung tumors. The standard deviation of DL scores obtained from each 4DCT image correlated with the magnitude of tumor motion (R² =0.45, p=0.005). Higher uncertainty in DL scores was attributed to the larger tumor motion. The average DL score obtained from the 10 phases of the 4DCT images of each patient was (i) highly associated with the DL scores obtained from the FBCT images (r = 0.99; p<0.0001), and (ii) closest to the DL score obtained with the end-inspiration images. In comparing the prediction performance across image acquisition types, MIP images yields a higher DL score compared to FBCT (<i>p</i><0.0001) or 4DCT images (<i>p</i> =<0.0001). <h3>Conclusion</h3> The impact of tumor motion on the range of DL scores for prediction of local recurrence was reported for the first time. Standard deviations of the DL scores increased with motion magnitude. However, when DL score was measured and averaged across the 10 phases of the 4DCT images, DL score correlated well with those obtained from the FBCT images. This preliminary finding suggests that despite the increased variation with larger motion, the DL score, when averaged across the sinusoidal breathing trajectory, correlates with the DL score obtained from the FBCT images that were used for treatment planning. However, caution should be exercised when using MIP images for local recurrence prediction since a higher DL score than the FBCT images used for planning will be observed.

Time to Resuscitate Cardiopulmonary Resuscitation: The 3R/CPR Refill-Recoil-Rebound

Introduction: Sudden cardiac arrest (SCA) remains a major healthcare issue worldwide with gloomy outcomes due to poor perfusion of cardiopulmonary resuscitation (CPR), deemed unsuitable for hemostatic conditions, cardiotorsal anatomy, electrophysiology, and thoracic biomechanics. Alternatively, we propose a new management, implementing rational exploitation of the stagnant blood masses: manually with a novel technique of cardiac massage and mechanically with a circulatory flow restoration (CFR) device.&#x0D; Methods: Simulated chest compressions were performed through the 5th intercostal space in professional Lifeguards volunteers, placed in the left lateral decubitus position with raised legs and abdominal compression.&#x0D; Results: Bypassing the sternal barrier, refilling the heart, and then compressing the chest with a recoil-rebound maneuver (3R / CPR) can significantly promote return of spontaneous circulation (ROSC). The effectiveness of the CFR device versus CPR has previously been demonstrated in the literature.&#x0D; Conclusion: Unlike current CPR, the 3R/CPR adapts human morphology and provides adequate myocardial perfusion promoting ROSC safely, under all circumstances. Preclinical computational models can confirm the effectiveness of the technique.

ABDOMINAL COMPRESSION IN END-STAGE FIBROTIC INTERSTITIAL LUNG DISEASE (ILD) IMPROVES RESPIRATORY COMPLIANCE

ABDOMINAL COMPRESSION IN END-STAGE FIBROTIC INTERSTITIAL LUNG DISEASE (ILD) IMPROVES RESPIRATORY COMPLIANCE

Exo-Abs: A Wearable Robotic System Inspired by Human Abdominal Muscles for Noninvasive and Effort-Synchronized Respiratory Assistance

Existing technologies for patients with respiratory insufficiency have focused on providing reliable assistance in their breathing. However, the need for assistance in other everyday respiratory functions, such as coughing and speaking, has remained unmet in these patients. Here, we propose Exo-Abs, a wearable robotic system that can universally assist wide-ranging respiratory functions by applying compensatory force to a user's abdomen in synchronization with their air usage. Inspired by how human abdominal muscles transmit pressure to the lungs via abdominal cavity compression, a biomechanically interactive platform was developed to optimally utilize the abdominal compression while aligning the assistance with a user's spontaneous respiratory effort. In addition to the compact form factor, thorough analytic procedures are described as initial steps toward taking the human respiratory system into the scope of robotics technology. We demonstrate the validity of the overall human–system interaction with the assistance performance under three essential respiratory functions: breathing, coughing, and speaking. Our results show that the system can significantly improve the performance of all these functions by granting on-demand and self-reliant assistance to its users.

S3716 A Rare Case of Ectopic Liver Tissue Incidentally Found in the Gastric Body

Introduction: Ectopic liver tissue (ELT) is seldom reported in the literature. It is usually asymptomatic and incidentally found. However, ELT has a strong association with malignant transformation to hepatocellular carcinoma (HCC), making removal of this tissue essential. Presented is a rare case of ELT found in the stomach. Case Description/Methods: A 78-year-old male with a past medical history of hypertension and gastritis presented to clinic for worsening gastroesophageal reflux disease (GERD) over the past six months. The patient reported GERD symptoms for the past twenty years that he had been self-treating with over-the-counter proton pump inhibitors, probiotics, and digestive enzymes without relief. On presentation his vitals, physical exam, and blood work were unremarkable. The patient underwent esophagoduodenoscopy (EGD) which revealed esophagitis, a large paraesophageal hernia, and a single 15-millimeter submucosal nodule in the anterior wall of the gastric body. Cold forceps biopsies obtained from the body and antrum of the stomach were unremarkable and negative for H. pylori. He was referred for endoscopic ultrasound (EUS), where a fine needle biopsy of the benign-appearing gastric body submucosal nodule was performed (figure 1a). Three passes were made with a 22-gauge ultrasound biopsy needle using a transgastric approach. A visible core of tissue was obtained. Final cytology demonstrated superficial gastric mucosa and detached benign liver tissue (figures 1b, 1c). No dysplasia or malignancy was seen. Discussion: ELT has an incidence of 0.24-0.47%. Of the reported cases, ELT is most commonly seen in the gallbladder or pancreas. The etiology of ELT is unknown but is thought to be associated with errors in embryological development. Most ELT is asymptomatic but can develop the same pathologies as the orthotopic liver. It can also cause abdominal pain, bleeding, and compression of neighboring tissues. There is also a strong association between HCC and ELT, necessitating biopsy and endoscopic removal. This case demonstrated ELT incidentally found in the gastric body during EGD and was biopsied by a fine needle using EUS guidance. Histology was without features to suggest malignancy, but to prevent malignant transformation endoscopic resection was recommended.Figure 1.: 1a. Arrow indicating nodule in gastric body, as seen by endoscopic ultrasound. Image 1b. Hematoxylin and eosin stain with 100x magnification. Normal gastric glandular mucosa. Arrow indicating benign unremarkable hepatic tissue found in gastric body. Image 1c. Hematoxylin and eosin stain with 200x magnification. Benign unremarkable hepatic tissue found in gastric body.

Implementation of closed incision negative pressure therapy in Enhanced Recovery After Surgery for immediate breast reconstruction with deep inferior epigastric artery perforator flap

Objectives: To compare the number of abdominal dehiscences in patients undergoing immediate breast reconstruction with Deep Inferior Epigastric artery Perforator flap (DIEP) before and after implementation of the Enhanced Recovery After Surgery (ERAS) protocol that adds postoperative Closed Incision Negative Pressure Therapy (ciNPT) to conventional abdominal binder compression therapy.

S644 ColoWrap Real-World Evidence: Colonoscopy Compression Device Mitigates Ergonomic Hazards for Endoscopists and Staff

Introduction: Looping during colonoscopy increases scope forces and torquing which are causes of ergonomic injury among endoscopists. In addition, manual abdominal pressure and patient repositioning, used to address looping in 52% and 34% of colonoscopies, respectively, are known causes of musculoskeletal injuries among endoscopy staff. ColoWrap (ColoWrap, LLC, Durham, NC) is an anti-looping abdominal compression device applied during colonoscopy to decrease looping and limit the need for manual pressure and patient repositioning. We aimed to determine extent to which ColoWrap reduces ergonomic hazards associated with colonoscopy by performing a chart review and obtaining physician and staff feedback following use of the device. Methods: This retrospective, multi-center, observational chart review included patients that underwent colonoscopy with the ColoWrap device between September 25, 2016, and June 15, 2022. Demographics and procedural information were abstracted from patient records. Physician and staff experiences were captured using a survey instrument. Results: 849 procedures were included in the review. The population was majority male (53%), over 60 (mean age: 60.8 ± 11.6), and obese (mean BMI: 33.6 ± 7.2). 49 patients (5.7%) had an abdominal hernia, 139 (16.3%) had at least one prior abdominal surgery, and 52 (6.1%) had a history of difficult or incomplete colonoscopy. Cecal intubation was achieved in 841 cases (99.1%). Mean cecal intubation time was 6.8 ± 6.2 (min). Manual pressure was used in 109 cases (12.8%); significant manual pressure ( > 3 min) was needed in only 21 procedures (2.5%). Patient repositioning was used in 48 cases (5.6%). No significant adverse events were reported. 84% of physicians indicated that ColoWrap use mitigated looping, shortened cecal intubation time, and reduced physical strain associated with advancing the scope. 90% of endoscopy staff reported reduced manual pressure and patient repositioning, and alleviation of musculoskeletal pain (Figure). Conclusion: ColoWrap is safe and significantly reduces manual pressure and patient repositioning during colonoscopy relative to published rates. Physicians using ColoWrap experience less looping and physical strain and endoscopy staff suffer less musculoskeletal pain. The device is a viable tool among solutions to improve the safety and efficiency of colonoscopy. Further studies to identify circumstances in which ColoWrap use offers the greatest benefit to patients, physicians, and staff are warranted.Figure 1.: Endoscopist and Endoscopy Staff Experience with ColoWrap Device

Effect of Low or High Pressure Alveolar Recruitment Maneuver on Postoperative Pain and Quality of Recovery in Patients with Obesity Undergoing Laparoscopic Sleeve Gastrectomy.

Background: This study aimed to evaluate whether a low- or high-pressure alveolar recruitment maneuver (ARM) might reduce postoperative pain and improve the quality of recovery after laparoscopic bariatric surgery. Methods: 90 patients with a body mass index > 30 kg/m2 scheduled for laparoscopic sleeve gastrectomy were randomly assigned to control (n = 30), low ARM (n = 30), or high ARM groups (n = 30). For the low and high ARM groups, ARM was repeated five times to hold the peak airway pressure at 30 cmH2O and 60 cmH2O for 5 s, respectively, before removal of the trocar. Conventional methods to reduce post-laparoscopic pain, such as intraperitoneal saline irrigation, hemovac drainage, and gentle abdominal compression were performed in all patients, regardless of the assigned group. Results: Shoulder and surgical site pain scores 24 h postoperatively and rescue meperidine requirement were similar between the groups (p = 0.141, 0.101, and 0.82, respectively). The quality of recovery 40 (QoR40) score 24 h postoperatively was similar between the groups (p = 0.755). Postoperative pulmonary complications were similar between the groups (p = 0.124). Conclusion: Application of a low- or high-pressure ARM in addition to conventional methods to remove remnant peritoneal CO2 gas did not reduce postoperative shoulder or surgical site pain or improve the quality of recovery after laparoscopic sleeve gastrectomy.

Dosimetric impact of intrafraction motion under abdominal compression during MR-guided SBRT for (Peri-) pancreatic tumors

Objective. Intrafraction motion is a major concern for the safety and effectiveness of high dose stereotactic body radiotherapy (SBRT) in the upper abdomen. In this study, the impact of the intrafraction motion on the delivered dose was assessed in a patient group that underwent MR-guided radiotherapy for upper abdominal malignancies with an abdominal corset. Approach. Fast online 2D cine MRI was used to extract tumor motion during beam-on time. These tumor motion profiles were combined with linac log files to reconstruct the delivered dose in 89 fractions of MR-guided SBRT in twenty patients. Aside the measured tumor motion, motion profiles were also simulated for a wide range of respiratory amplitudes and drifts, and their subsequent dosimetric impact was calculated in every fraction. Main results. The average (SD) D 99% of the gross tumor volume (GTV), relative to the planned D 99%, was 0.98 (0.03). The average (SD) relative D 0.5cc of the duodenum, small bowel and stomach was 0.99 (0.03), 1.00 (0.03), and 0.97 (0.05), respectively. No correlation of respiratory amplitude with dosimetric impact was observed. Fractions with larger baseline drifts generally led to a larger uncertainty of dosimetric impact on the GTV and organs at risk (OAR). The simulations yielded that the delivered dose is highly dependent on the direction of on baseline drift. Especially in anatomies where the OARs are closely abutting the GTV, even modest LR or AP drifts can lead to substantial deviations from the planned dose. Significance. The vast majority of the fractions was only modestly impacted by intrafraction motion, increasing our confidence that MR-guided SBRT with abdominal compression can be safely executed for patients with abdominal tumors, without the use of gating or tracking strategies.

Impact of an Abdominal Compression Bandage on the Completion of Colonoscopy for Obese Adults: A Prospective Randomized Controlled Trial

Methods Eligible patients were randomly allocated into the abdominal bandage and conventional groups during a routine colonoscopy. The primary outcome was CCR. Results A total of 250 eligible patients were randomly assigned to the abdominal bandage and conventional groups from January 2021 to April 2021. Eleven patients (five in the abdominal bandage group and six in the conventional group) were excluded due to schedule cancellation after randomization, and 239 patients were eventually included in the final analysis. There were no significant differences between the two groups regarding baseline characteristics (P > 0.05). Furthermore, no significant differences were observed in terms of advanced adenoma detection rate (AADR), polyp detection rate (PDR), bowel preparation scale (BBPS), bubble scale (BS), and withdrawal time between the two groups (P > 0.05). However, compared with the conventional group, the cecal insertion time (CIT) of the abdominal bandage group was significantly shortened (279.00 (234.50–305.75) vs. 421.00 (327.00–485.00), P < 0.001), and the CCR (96.7% vs. 88.2%, P = 0.01) and adenoma detection rate (ADR) (47.5% vs. 32.8%, P < 0.001) were improved. Besides, logistic regression analysis showed that body mass index (BMI) and abdominal compression bandage were associated with CCR. Conclusions Abdominal compression bandages could effectively shorten CIT and improve CCR and ADR for obese patients during a routine colonoscopy. This trial is registered with the Chinese Clinical Trial Registry (No. ChiCTR2100043556).

Historical Review of The Development, Technique, Safety, and Efficacy of Interposed Abdominal Compression Cardiopulmonary Resuscitation as a Promising Adjunct with Standard CPR

Interposed abdominal compression cardiopulmonary resuscitation, henceforth referred to as IAC-CPR, is an adjunct to standard CPR (S-CPR) according to American Heart Association (AHA) guidelines since 1992.

An integrated ultrasound imaging and abdominal compression device for respiratory motion management in radiation therapy.

Radiotherapy to tumors in the abdomen is challenging because of the significant organ movement and tissue deformation caused by respiration. A motion management strategy that integrated ultrasound (US) imaging with abdominal compression was developed and evaluated, where US was used to real-time monitor organ motion after abdominal compression. A device that combined a US imaging system and an abdominal compression plate (ACP) was developed. Twenty-one healthy volunteers were involved to evaluate the motion management efficacy. Each volunteer was immobilized on a flat bench by the device. Abdominal US data were successively collected with and without ACP compression, and experiments were repeated three times to verify the imaging reproducibility. A template matching algorithm based on normalized cross-correlation was implemented to track the targets (vessels in the liver, pancreas, and stomach) automatically. The matching algorithm was validated by comparing with the manual references. Automatic tracking was judged as failed if the center-of-mass difference from manual tracking was beyond a failure threshold. Based on the locations obtained through the template matching algorithm, the motion correlation between liver and pancreas/stomach was investigated using the Pearson correlation test. Paired Student's t-test was used to analyze the difference between the results without and with ACP compression. The liver motion amplitude over all 21 volunteers was significantly (p<0.001) reduced from 14.9±5.5/3.4±1.8mm in superior-inferior (SI)/anterior-posterior (AP) direction before ACP compression to 7.3±1.5/1.6±0.7mm after ACP compression. The mean liver motion standard deviation before compression was on average 2.8/1.4mm in SI/AP direction and was significantly (p<0.001) reduced to 0.9/0.4mm after compression. The failure rates of automatic tracking for liver, pancreas, and stomach were reduced for failure thresholds of 1-5mm after applying ACP. The Pearson correlation coefficients between liver and pancreas/stomach were 0.98/0.97 without ACP and 0.96/0.94 with ACP in the SI direction and were 0.68/0.68 and 0.43/0.42 in the AP direction. The motion prediction errors for pancreas/stomach with ACP have significantly (p<0.001) reduced to 0.45±0.36/0.52±0.43mm from 0.69±0.56/0.71±0.66mm without ACP in the SI direction, and to 0.38±0.33/0.39±0.27mm from 0.44±0.35/0.61±0.59mm in the AP direction. The proposed strategy that combines real-time US imaging and abdominal compression has the potential to reduce the abdominal organ motion while improving both target tracking reliability and motion reproducibility. Furthermore, the observed correlation between liver and pancreas/stomach motion indicates the possibility of indirect pancreas/stomach tracking using liver markers as tracking surrogates. The strategy is expected to provide an alternative for respiratory motion management in the radiation treatment of abdominal tumors.

Evaluation of abdominal compression–decompression combined with chest compression CPR performed by a new device: Is the prognosis improved after this combination CPR technique?

IntroductionThis study was designed to compare the outcomes of standard cardiopulmonary resuscitation (STD-CPR) and combined chest compression and abdominal compression–decompression cardiopulmonary resuscitation (CO-CPR) with a new device following out-of-hospital cardiac arrest (OHCA). Moreover, we investigated whether patient prognosis improved with this combination treatment.MethodsThis trial was a single-centre, prospective, randomized trial, and a blinded assessment of the outcomes was performed. A total of 297 consecutive patients with OHCA were initially screened, and 278 were randomized to the STD-CPR group (n = 135) or the CO-CPR group (n = 143). We compared the proportions of patients who achieved a return of spontaneous circulation (ROSC), survived to hospital admission and survived to hospital discharge. In addition, we also performed the Kaplan–Meier analysis with a log-rank test at the end of the follow-up period to compare the survival curves of the two groups.ResultsThe differences were not statistically significant in the proportion of patients who achieved ROSC [31/135 (23.0%) versus 35/143 (24.5%)] and survived to hospital admission [28/135 (20.7%) versus 33/143 (23.1%)] between the CO-CPR group and STD-CPR group. However, there was a significant difference in the proportion of patients who survived to hospital discharge [16/135 (11.9%) versus 7/143 (4.9%)] between the two groups. Nine patients (6.7%) in the CO-CPR group and 2 patients (1.4%) in the STD group showed good neurological outcomes according to the cerebral performance category (CPC) scale score, and the difference was statistically significant (P = 0.003). The Kaplan–Meier curves showed that the patients in the CO-CPR group achieved better survival benefits than those in the STD-CPR group at the end of the follow-up period (log-rank P = 0.007).ConclusionCO-CPR was more beneficial than STD-CPR in terms of survival benefits in patients who have suffered out-of-hospital cardiac arrest.Trial registration Chinese Clinical Trial Registry, registered number: ChiCTR2100049581. Registered 30 July 2021- Retrospectively registered. http://www.medresman.org.cn/uc/index.aspx.

Cross-sectional Imaging of the Duodenum: Spectrum of Disease.

Cross-sectional Imaging of the Duodenum: Spectrum of Disease.

Effect of Interposed Abdominal Compression on Cardiopulmonary Resuscitation Outcomes; a Randomized Clinical Trial.

Introduction:Standard cardiopulmonary resuscitation (STD-CPR) is successful in only 10-15% of cases in emergency department (ED). This study aimed to determine the effect of interposed abdominal compression (IAC) during resuscitation on outcomes of ED cardiac arrests.Methods:In this randomized clinical trial study, non-trauma patients aged 18-85 years, patients with in-hospital cardiac arrest hospitalized in the ED were randomly assigned into two either STD-CPR or IAC-CPR group on a 1:1 basis and using computer-generated random numbers. Participants in the intervention group, received abdominal compression during the diastole phase of STD-CPR. The rate of return of spontaneous circulation (ROSC), heart rate (HR), respiratory rate (RR), arterial blood gas (ABG) indicators, and survival rate were compared between the two groups. Results:Ninety patients were enrolled (45 in each group). There were no differences between the two groups regarding age (p = 0.76), sex (p = 0.39), employment status (p = 0.62) and Charlson comorbidity scale (p = 0.46). Abdominal compression had a positive effect on heart rate (p < 0.001), mean arterial pressure (p = 0.003), arterial blood oxygen pressure (p = 0.001), and arterial blood carbon dioxide pressure (p = 0.001) as well as a negative effect on arterial blood oxygen saturation (p = 0.029) 30 minutes after resuscitation. Out of the 90 CPR cases, 8 (17.7%) cases in intervention group and 8 (17.7%) cases in control group were successful, among which all of the 8 patients in the intervention group and 5 of the patients in the control group had been discharged from hospital without any complications. Conclusion: The results showed that abdominal compression during CPR can improve resuscitation outcomes in patients with cardiac arrest. Therefore, in order to use this technique, further research is recommended.

Analysis of 6YO pediatric human body model kinematics and kinetics to determine submarining across naturalistic seating postures

Objectives The aim of this study was to analyze the kinematics and kinetics of a naturalistically seated 6-year-old (6YO) pediatric human body model and evaluate the metrics described by earlier studies for pediatric ATDs to indicate whether different postures and booster seats were more associated with submarining than others in a frontal impact. Methods The PIPER 6YO pediatric human body model was restrained on a lowback (LBB) and a highback (HBB) booster child restraint seat (CRS) in four naturalistic seating postures: leaning-forward, leaning-inboard, leaning-outboard, and a pre-submarining posture, and a baseline reference seating position as per the FMVSS No. 213 protocol. A 2012 mid-size sedan finite element (FE) model was used as the vehicle environment. A standard 3-point lap-shoulder belt system was modeled to restrain the child and the CRS in the left-rear vehicle seat. Additionally, a No-CRS condition was modeled in a reference posture and pre-submarining posture in which the occupant’s legs bent over the edge of the rear seat. 12 conditions were simulated in LS-DYNA R10.1.0, and kinematics and kinetics were compared to metrics as per prior literature: 1) maximum femur displacement and pelvis rotation, 2) maximum knee-head excursion and maximum change in torso angle, 3) lap belt trajectory relative to pelvis’s coordinate frame. Results The pre-submarining posture on the HBB depicted submarining in all metrics except for the lap belt trajectory. Only the pre-submarining posture in No-CRS depicted submarining through analysis of all metrics. For this pre-submarining No-CRS condition, the mid-abdominal compression was approximately 5 times greater than the average of the mid abdominal compression depths of all other cases and maximum abdominal pressure was at least 22.9 kPa higher than the rest of the conditions. Conclusions The results of this study suggest that metrics used to assess submarining for 6YO pediatric occupants in frontal impacts may need to be updated so that they are more accurate for both simulated and physical studies. In addition, the results of this study could be used to design booster seats that discourage postures that could lead to an increased likelihood of submarining-like characteristics in a frontal crash impact.

Radiotherapy respiratory motion management in hepatobiliary and pancreatic malignancies: a systematic review of patient factors influencing effectiveness of motion reduction with abdominal compression

Background The effectiveness of abdominal compression for motion management in hepatobiliary-pancreatic (HPB) radiotherapy has not been systematically evaluated. Methods & materials A systematic review was carried out using PubMed/Medline, Cochrane Library, Web of Science, and CINAHL databases up to 1 July 2021. No date restrictions were applied. Additional searches were carried out using the University of Manchester digital library, Google Scholar and of retrieved papers’ reference lists. Studies conducted evaluating respiratory motion utilising imaging with and without abdominal compression in the same patients available in English were included. Studies conducted in healthy volunteers or majority non-HPB sites, not providing descriptive motion statistics or patient characteristics before and after compression in the same patients or published without peer-review were excluded. A narrative synthesis was employed by tabulating retrieved studies and organising chronologically by abdominal compression device type to help identify patterns in the evidence. Results The inclusion criteria were met by 6 studies with a total of 152 patients. Designs were a mix of retrospective and prospective quantitative designs with chronological, non-randomised recruitment. Abdominal compression reduced craniocaudal respiratory motion in the majority of patients, although in four studies there were increases seen in at least one direction. The influence of patient comorbidities on effectiveness of compression, and/or comfort with compression was not evaluated in any study. Conclusion Abdominal compression may not be appropriate for all patients, and benefit should be weighed with potential increase in motion or discomfort in patients with small initial motion (<5 mm). Patient factors including male sex, and high body mass index (BMI) were found to impact the effectiveness of compression, however with limited evidence. High-quality studies are warranted to fully assess the clinical impact of abdominal compression on treatment outcomes and toxicity prospective in comparison to other motion management strategies.

Development of a novel airbag system of abdominal compression for reducing respiratory motion: preliminary results in healthy volunteers.

This study used cine-magnetic resonance imaging (cine-MRI) to evaluate the safety and efficacy of a novel airbag system combined with a shell-type body fixation system in reducing respiratory motion in normal volunteers. The airbag system consists of a six-sided polygon inflatable airbag, a same shape plate, a stiff air supply tube, an air-supply pump and a digital pressure load cell monitor. Piezoelectric sensors were installed in the plate to detect compression pressure load changes; pressure load data were transferred to the digital pressure load cell monitor through Bluetooth. Five volunteers underwent cine-MRI with and without airbag compression to detect differences in the respiratory motion of the organs. The volunteers’ physiologic signs were stable during the experiment. The maximum inspiration pressure load was 4.48 ± 0.86 kgf (range, 4.00–6.00 kgf), while the minimum expiration pressure load was 3.69 ± 0.95 kgf (range, 2.8–5.3 kgf). Under airbag compression, the right diaphragm movement was reduced from 19.50 ± 6.43 mm to 9.60 ± 3.61 mm (P < 0.05) in the coronal plane and 23.12 ± 6.30 mm to 11.00 ± 3.69 mm (P < 0.05) in the sagittal plane. The left diaphragm, pancreas and liver in the coronal plane and the right kidney and liver in the sagittal plane also showed significant movement reduction. This novel airbag abdominal compression system was found to be safe during the experiment and successful in the reduction of internal organ respiratory motion and promises to be a convenient and efficient tool for clinical radiotherapy.