Catheter Position Research Articles

Bioinspired intratumoral infusion port catheter improves local drug delivery in the liver.

Tumor immune modulation can be achieved using intratumoral injection of different immunomodulators during different phases of the cancer-immunity cycle. Intratumoral infusion catheters have been used in brain tumors, but these are not suitable outside the brain, where breathing motion results in catheter migration. Here, we use microstereolithography to manufacture a barbed sidehole catheter, modeled after the barbs in a bee stinger, where the barbs maintain the catheter position in the tumor, and sideholes within the barbs infuse drug into tumor tissue. In pig liver, we demonstrated 183-fold higher local drug concentration using the barbed sidehole catheter, compared to intravenous injection of water-soluble drug. High resistance sideholes and pulsatile injection both generate higher pressure in the catheter, which overcomes the tissue pressure, resulting in more drug delivery into tumor. A physical model of intratumoral infusion catheters accurately predicts the observed drug delivery results. Our catheter design is retained in the liver (and does not migrate out with breathing motion), and it preferentially infuses the drug into tumor tissue (not intratumoral vessels).

DDEL-06. CONVECTION-ENHANCED DELIVERY OF SEVEN DIFFERENT MOLECULES SHOW LARGE DIFFERENCES IN CONVECTIVE PROPERTIES BETWEEN MOLECULES. INFORMED DECISION MAKING FOR OPTIMIZED CATHETER PLACEMENT AND SUBSEQUENT INFUSION STRATEGIES

Abstract INTRODUCTION Glioblastoma (GBM) trials based on convection-enhanced drug delivery (CED) bypassing the blood-brain barrier have failed to prove efficient until now. Many factors influence CED. In this study we evaluated CED of seven different molecules using dynamic PET/MRI during infusion. This enabled in-depth evaluation of drug distribution and concentration gradients providing a more precise understanding of the Vd/Vi ratio and the extent of efficacy level across the Vd zone. Novel surgical catheter placement software algorithms, results in more informed-decision-making for catheter positioning and subsequent infusion planning strategies. METHODS Pigs were implanted with neuroinfuse™ drug delivery systems enabling intermittent drug infusions. Gadolinium, [124I]-UdR, [55Co]Co-DOTA-hEGF, [55Co]Co-DOTA-SP4, [18F]PSMA-1007 and three differently sized [64Cu]-labelled nanocarriers were evaluated in both pigs with and without a brain resection cavity. Gadolinium distribution was followed by MRI. PET imaging was used for the rest. To inform clinical trial design, strategic catheter placement and volumes to be infused, planning was investigated on several historical GBM cases. RESULTS Vd/Vi ratios ranged between 1.00 – 3.77. where large-sized liposomes performed best. Catheters stayed patent during weeks of repeated infusions. In the resected animals no leakage of drugs into the brain resection cavity was observed. Effective 3D modelling of novel catheter infusion planning aids provided visualized representations of tailor-made infusion plumes, capable of being suitably positioned to optimize surgical planning of catheters and transcutaneous reaccess port. CONCLUSION Large differences in convective properties between different molecules were observed. Large-sized liposomes as drug-carrier system showed superior performance to all other molecules. Vd/Vi ratios for promising drugs should be determined before initiating future clinical CED trials. Infusion concentration gradients to facilitate more precise Vd/Vi ratios provided important performance metrics for visualised infusion planning aids of a novel chronic drug delivery system, illustrating informed decision making for optimised catheter placement and subsequent infusion strategies is clinically translatable for GBM indications.

The impact of real-time ultrasound guidance on ventricular catheter placement in cerebrospinal fluid shunts - a single-center study.

Misplacement of ventricular catheters during shunt surgery occurs in 40% of cases using a freehand technique and therefore represents a risk for early shunt failure. The goal of this retrospective, single-center study is to analyze the impact of real-time ultrasound guidance on ventricular catheter positioning and early outcome of shunt survival. We analyzed the charts and images of all patients who underwent shunt surgery from 09/2017 to 12/2022 and compared the position of the ventricular catheter using the freehand technique and real-time ultrasound guidance. Central catheter position was graded as grade I (optimal), II (contact with ventricle structures or contralateral), and III (misplacement). A ventricular catheter was placed in 244 patients using real-time US guidance and in 506 patients using a freehand technique. The mean age (53.4 and 53.6 years, respectively) and the preoperative frontal occipital horn ratio (FOHR; 0.47 versus 0.44) were almost equal in both groups. In the study group, grade I catheter position was achieved in 64% of cases, grade II in 34%, and grade III in 2%. The control group showed grade I position in 45%, grade II in 32%, and grade III in 23% of cases (p<0.05). An early central catheter failure rate was the highest in grade III (40.5%) compared to 4% in grade I. Our data demonstrate that real-time US guidance leads to a significant improvement in ventricular catheter placement. Consequently, early shunt revisions decrease significantly. Further prospective, randomized, and controlled studies comparing the standard method to real-time ultrasound catheter placement are required.

A simple calculation formula for the insertion depth of catheter of the central venous access port in Chinese patients

BackgroundThe catheter tip placed between the T6 and T7 vertebrae is recognized as an optimal position for the totally implantable venous access ports (TIVAPs). This study aimed to propose a simple formula for calculating the optimal insertion depth of the right internal jugular central venous catheter (CVC) of TIVAP in Chinese patients. MethodsThis was a prospective observational study. The medical records of 151 patients with TIVAPs placement were retrospectively analyzed. Patient's height and actual insertion depth of CVC were used to build a simple linear regression model. The Peres’ formula was revised to better calculate the optimal insertion depth of the right internal jugular CVC of TIVAPs, accounting for population-specific anatomical variations observed in Chinese patients. A total of 158 patients scheduled for TIVAPs placement were prospectively recruited. The insertion depth of catheter was preoperatively determined according to the established formula, and postoperative chest X-ray was performed to determine the position of catheter tip. The rate of proper position of catheter (the catheter tip within T6 or T7 vertebrae) was calculated to assess the clinical feasibility and effectiveness of the new formula. ResultsThe proper position rate was 64.24% (97/151) in the retrospective group. According to patients’ height and insertion depth of CVC of these 97 cases with proper position, Peres’ formula was revised to ‘insertion depth = 0.1*height – 4 (cm)’. Based on insertion depth predicted by the new formula, the proper position rate in the prospective group reached 86.08% (136/158). ConclusionThe simple formula for calculating the insertion depth of right internal jugular CVC of TIVAPs is clinically feasible for Chinese patients.

Value of projectional imaging relative to cross-sectional imaging to assess catheter tip position in the superior vena cava: Evaluation of reader variability.

The assessment of correct positioning of central venous catheters (CVC) is of major concern to avoid complications.Vascular access associations have established the cavo-atrial junction (CAJ) as the most appropriate CVC tip location. Among the different chest X-ray (CXR) landmarks proposed for assessing tip position relative to the CAJ, only the pericardial reflection lies in the same plane as the vascular structures assessed. Although extensively used, CXR has been criticized for its difficulty in estimating catheter tip location.We aimed to evaluate the observer variability to determine tip positioning on CXR. CT imaging was used as a gold standard for tip identification. 107 CT scans of patients wearing port access catheter devices realized at the XXX University Hospital between January and December 2021 were retrospectively analyzed. Distance from tip to cavo-atrial junction (DCAJ) was measured on topogram projectional imaging (PJ) and axial cross-sectional imaging (CS) by 2 × 2 observers (within and between evaluations). Observational statistics were reported using a paired t-test, repeatability coefficients (RC), and the intraclass correlation coefficient (ICC), and they were displayed comprehensively using Bland-Altman plots. All ICC were >0.9, indicating excellent reliability. The mean difference between observers comparing CS and PJ was 0.13 ± 0.80 cm (P = 0.10) with outer 95% confidence limits of 1.92 cm and -2.17 cm and an RC of 1.79 cm. CXR tip-position reading remains an accurate method for determining CVC localization. However, the assessment variability on CXR is plus or minus 2 cm and should be considered. Chest X-ray (CXR) for the assessment of tip position is subject to intra-individual and inter-individual variation. On CT, the variability is solely linked to determining the cavoatrial junction (CAJ) and represented about 1 cm. On CXR, there is a twofold challenge: the correct determination of the CAJ and the accurate identification of the catheter tip, leading to a greater variability of 2 cm.In clinical practice, while considering the 3 cm anatomical zone around the CAJ acceptable, operators should be aware of the 2 cm variability resulting from CXR assessment. To account for this variability and avoid the risk of positioning the tip beyond 3 cm from the CAJ (theoretically up to plus or minus 5 cm away from the CAJ), operators should reduce the CXR-based acceptable zone to 1 cm around the CAJ. This change may impact up to thirty percent of procedures.

Impact of conduction velocity in left atrium assessing with omnipolar technology in patients with atrial fibrillation

Abstract Background There is increased interest in exploring substrate of atrial fibrillation (AF) and recent studies have shown that atrial conduction velocity (CV) reflects the electrophysiological phenomena and plays key role in perpetuating AF. The novel omnipolar technology (OT) use three unipolar and two orthogonal bipolar signals allow us to analyze the voltage, activation direction, and CV independent of catheter position. Objective The purpose of the present study was to evaluate if the left atrium (LA) CV which assessed by OT predict the any atrial tachy-arrhythmia (AT) recurrence after initial AF ablation. Methods We enrolled 58 consecutive patients who underwent initial pulmonary vein isolation (PVI) for drug refractory AF. (mean age: 68.2±10.2 years old, 32 male(55.1%), 32 persistent AF(55.1%), CHADS2 score:1.6±0.6). After electrical PVI was achieved and remained in sinus rhythm, the LA was mapped with high density mapping catheter (Advisor HD Grid, Abott USA) utilizing with the novel OT combined with Ensite X system (Abott, USA). The conduction distance and conduction times were measured from the earliest activation site to the latest activation site in LA (Figure 1). Each conduction velocity in anterior, posterior, and septal area were also calculated as conduction distance divided by conduction time. The LA voltage was also measured. Results During a mean follow up period of 316±143 days, the recurrence of AT after initial PVI was observed in 9 (15.5%) patients. There were no significant differences in baseline demographics between AT recurrence and non-recurrence group (mean age:66±13.3 vs 68.5±10.5 years old P=0.66, CHADS2 score: 1.5±0.57 vs 1.68±0.62 P=0.59, proportion of persistent AF: 15.4% vs 15.5% P=0.82, LA volume: 102±35.9 vs 93.6±37.3ml P=0.63). The earliest activation site in LA were identified in 3 areas including anterior site of right pulmonary vein (51.7%), Bachmann bundle area (41.4%), and antero-septal area (6.89%) (Figure 2). In patients with AT recurrence, the CV in LA was significantly slower than those without AF recurrence(0.61±0.21 vs 0.81±0.16 m/s, P=0.036) whereas the whole LA voltage was not (1.52±0.75 vs 2.22±1.06 mv, P=0.28). The CV in each LA portion are similar between recurrence and non-recurrence AT group. (anterior:0.57±0.24 vs 0.81±0.23 m/s, P=0.18, posterior: 0.87±0.18 vs 1.2±0.49 m/s P=0.36, septal: 0.89±0.76 vs 1.15±0.39 m/s, P=0.41). Conclusion The earliest activation site in LA was varied in each case. The whole CV in LA is a predictor of AF recurrence after PVI whereas the CV of each LA portion and LA voltage was not.

Quantifying cardiac tissue heterogeneity using high-density grid catheter: validation in porcine model

Abstract Background and Objectives Characterizing cardiac substrate is crucial for diagnosing and treating cardiac arrhythmias due to its association with the presence of fibrotic tissue. Omnipolar Electrogram (EGM) technology provides orientation-independent signal generation and instantaneous propagation direction determination. Although traditionally, the amplitude of the bipolar signal has been the most used metric, it alone does not suffice for comprehensive tissue characterization. Recently, a novel metric has been developed to quantify the degree of directional propagation disorganization within cardiac tissue, defined as Vector Field Heterogenity (VFH)[1] that can provide additional insights to the tissue characterization. Due to the presence of tissues with varying impedance, changes in the direction of propagation of cardiac electrical signals can occur. Therefore, the objective of this study is to characterize how the presence of fibrotic or necrotic tissue can influence the disorganization of electrical activity propagation, and thus assess the effectiveness of the heterogeneity metric in characterizing these tissues. Method We worked with a database of a female swine records of the left atrium. These records include data pre and post-ablation by electroporation. From the unipolar signals available in the database, we have calculated the Omnipolar EGMs in cross configuration. From the omnipolar signals, we calculated the propagation direction. On this propagation direction, we applied the heterogeneity metric for each catheter position along all the left atrium. This metric has a normalized range between 0 and 1, 0 describing the minimum disorganization and 1 the maximum. These calculations have been applied in the same way in the registers pre and post-ablation to evaluate the differences. Results Pre-procedure bipolar peak-to-peak voltages averaged 2.7591mV (SD = 3.4257), decreasing post-procedure to 0.754mV (SD = 1.1666), (p&amp;lt; 0.0001) indicating a significant decrease in bipolar amplitude following ablation. Heterogeneity scores increased post-ablation (mean = 0.3753, SD = 0.21218; post: mean = 0.53526, SD = 0.1320, p&amp;lt;0.0001. This indicates that after ablation, not only does the signal amplitude decrease, but also the level of disorganization of electrical propagation increases. These findings are visually depicted in Figure 1. Conclusion The ablation procedure led to reduced tissue electrical activity, manifested by decreased amplitude and increased propagation heterogeneity, indicative of tissue disorganization. Transitioning from homogeneous to heterogeneous conduction post-ablation suggests the presence of necrotic tissue, hindering uniform wave propagation. This highlights the significance of heterogeneity scoring in evaluating tissue health and ablative intervention outcomes.Figure 1.Catheter HD Grid

Real-time ultrasound to assess the umbilical catheter position in neonates: a randomized, controlled trial.

To compare real-time ultrasound (RT-US) use as an adjunct tool to verify umbilical catheter placement versus standard care without ultrasound. Neonates requiring umbilical venous catheter (UVC) and umbilical artery catheter (UAC) placement were randomized into the standard formula (No-US) and the RT-US groups. X-rays were used to confirm the catheter position. Fifty and forty-nine neonates were in the RT-US and No-US groups, respectively. RT- US showed a significantly higher rate of initial X-ray-confirmed proper catheter position than No-US (p < 0.001). The rates of proper positions of UVCs and UACs were significantly higher in the RT-US group than in the No-US group (both p < 0.001). Neonates in the RT-US group required fewer catheter adjustments and subsequent X-rays than those in the No-US group. RT-US enhances the accuracy of UVC and UAC placement, reduces catheter adjustments, and the number of X-rays required. TCTR20190622001.

Successful placement of a chest wall venous infusion port via persistent left superior vena cava: A case report.

Persistent left superior vena cava (PLSVC) is a rare congenital venous anomaly occurring in approximately 0.3% to 0.5% of the population. The presence of PLSVC complicates central venous catheter placement, increasing procedural risks. This case report describes the successful placement of a chest wall venous infusion port in a patient with PLSVC, offering valuable insights for managing similar cases and ensuring safer clinical outcomes. A 51-year-old female, 3 weeks post-right breast cancer surgery, was admitted for her first adjuvant hemotherapy session. She requested the placement of a venous infusion port due to the prolonged duration of chemotherapy. Imaging studies suggested the presence of PLSVC. Echocardiography revealed a dilated coronary sinus, and subsequent chest computed tomography and angiography confirmed the presence of PLSVC. A chest wall venous infusion port was inserted via the left internal jugular vein. Due to the PLSVC, the catheter was adjusted to ensure proper placement. The patient successfully completed chemotherapy without any complications or discomfort associated with the venous port. Imaging studies, including chest X-ray and computed tomography, confirmed proper port function and catheter positioning, with no evidence of thrombosis, infection, or other related issues. The patient remained in good overall condition throughout the treatment. Detailed preoperative evaluations, intraoperative imaging guidance, and postoperative follow-ups are crucial for the safe and effective management of PLSVC patients undergoing central venous catheter placement.

A-056 Investigating Iodine Contrast Contamination in Cortisol and Aldosterone Samples

Abstract Background Primary aldosteronism (PA) is a condition characterized by hypertension resulting from excess secretion of aldosterone. PA caused by a unilateral aldosterone-producing adenoma can be treated with adrenalectomy but requires diagnosis by adrenal vein sampling (AVS). In this procedure, intravenous cosyntropin is administered to stimulate adrenal cortical secretion, followed by obtaining samples from the right and left adrenal veins and IVC. Laterization index is calculated by obtaining the aldosterone:cortisol ratio for each side, with a ratio cutoff ≥3 is used for confirmation. Iodinated contrast media facilitates visualization of catheter positioning during AVS and sometimes results in contamination of samples, evidenced by abnormal gel separator flotation (i.e. gel above plasma). This study had two aims: 1) to determine at what concentration contrast dye causes gel flotation and 2) discern whether contrast media interferes with our cortisol or aldosterone assays. Methods Gel flotation studies were performed by spiking pooled plasma samples with iohexol contrast media (Omnipaque 240, GE Healthcare) at concentrations ranging from 3%-10% v/v and aliquoting into fresh lithium heparin plasma separator tubes (BD, PSTs). Samples were then centrifuged and visually inspected for abnormal gel flotation. Contrast interference studies were performed using three pools of low (5 µg/dL), medium, (30 µg/dL), and high (55 µg/dL) cortisol concentrations. Sample pools were diluted with 20% contrast media or saline (control) and subsequently mixed at different ratios to create a range of dye concentrations (0.5%-18% v/v). Each mixture was assayed in triplicate for cortisol and aldosterone on a cobas e602 (Roche Diagnostics) and LIAISON XL (DiaSorin) immunoanalyzer, respectively. The total allowable error (TEa) was ±0.4 μg/dL or ±20% for cortisol and ±2 ng/dL or ±20% for aldosterone. Results Flotation of the gel separator was observed at a dye concentration of 4.5% v/v and greater. For the cortisol interference study, the bias was &amp;lt;5% for the three pools at all contrast media concentrations. Aldosterone was also measured in these pools, as bias could affect ratios calculated for PA. Aldosterone interference occurred at contrast dye concentrations ranging from 12%-20% v/v. An average positive bias of 34% was observed in aldosterone samples spiked with contrast media relative to the saline control. Compared to sample pool controls without added saline or dye, measurements for cortisol and aldosterone were 19%-22% and 16-25% lower in media- and saline-spiked samples (20% v/v), respectively, indicating a logical dilution effect. Conclusions Contrast dye contamination of AVS specimens can cause gel flotation in lithium heparin PSTs, preventing their analysis. The presence of contrast media at certain concentrations interfered with the DiaSorin aldosterone assay, leading to falsely elevated results. No cortisol assay interference occurred in the presence of contrast media but results were falsely decreased due to sample dilution. Samples collected during AVS may be contaminated with contrast dye causing gel flotation to occur. This is indicative of a minimum contrast media concentration of 4.5% v/v. Aldosterone:cortisol ratios may be inaccurate due to the positive aldosterone immunoassay bias with contrast media contamination. Care should be taken when reporting and interpreting AVS results with suspected contamination.

Utrasound as a method for confirming the positioning of enteral catheters in critically ill patients.

To evaluate the agreement between the bedside ultrasound in a single epigastric window and the plain X-ray to confirm the positioning of the enteral catheter in critically ill patients. This was an observational, cross-sectional study conducted in two Intensive Care Units of a university hospital. The ultrasound exams were carried out immediately after the introduction of the enteral catheter, using only the epigastric window, with an injection of 5 ml of air associated with 5 ml of saline solution. In all cases, the plain radiography was taken to confirm the positioning of the enteral catheter and to define the beginning of nutritional therapy. This study included 83 patients, the positioning of the enteral catheter was confirmed by plain radiography in all cases and by ultrasound in 81 (97.6%) patients. The median duration of the ultrasound exam was 2 (2-3) minutes, while the time spent between the request for the X-ray and the release of the exam for a doctor's appointment was 225 (120-330) minutes. Bedside ultrasound proved to be an effective, quick, and safe method to confirm the position of the enteral catheter in critically ill patients.

Intraoperative cone-beam computed tomography for catheter placement verification in pediatric hydrocephalus: technical note.

Ventriculoperitoneal (VP) shunt placement, essential for managing hydrocephalus, often risks catheter malpositioning, especially in patients with small ventricles. We present a novel technique combining neuronavigation with intraoperative cone-beam computed tomography using the BrainLab system and Loop-X mobile imaging unit. This approach enables real-time verification of catheter placement by integrating preoperative MRI data with intraoperative CT imaging. In a 12-year-old boy with therapy-refractory idiopathic intracranial hypertension, neuronavigation was guided by the BrainLab Skull Fix and Cushing canula, ensuring precise catheter insertion into the right frontal horn. Post-placement, Loop-X facilitated immediate verification of the catheter's trajectory and positioning, corroborated by postoperative MRI. This technique demonstrated high precision and minimized radiation exposure, emphasizing its utility in reducing revision rates due to suboptimal catheter placement.

Peripherally Inserted Central Catheter Tip Malposition in Neonates: A Comparison of Placement in the Head &amp; Neck, Upper Extremity, and Lower Extremity

Background: While catheter lengths are determined based on guidelines, regional studies should be considered to ensure optimal catheter placement. Objectives: This study aimed to compare the incidence of tip malposition and the amount of catheter retraction required to achieve appropriate placement in peripherally inserted central catheters (PICC) inserted in the head and neck, upper extremities, and lower extremities to determine the optimal catheter placement site. Methods: This cross-sectional study was conducted in the Children's Medical Center NICU between 2020 and 2021. After the initial calculation of catheter insertion length based on guidelines, PICC placement was performed by two skilled nurses. The catheter position was then confirmed, and the amount of catheter retraction was compared for each group. Results: A total of 368 neonates were included in the study. The results showed a statistically significant higher incidence of catheter tip malposition in the upper extremity group (P-value = 0.004). The minimum amount of catheter retraction required to achieve proper placement was 1 cm. Conclusions: This study suggests that the formula for calculating the length of the catheter in the upper extremities should be adjusted. However, further studies are needed to confirm this.

The use of Intracardiac Echocardiography in Catheter Ablation of Atrial Fibrillation.

Intracardiac echocardiography (ICE) provides real-time, fluoroless imaging of cardiac structures, allowing optimal catheter positioning and energy delivery during ablation procedures. This review summarizes the use of ICE in catheter ablation of atrial fibrillation (AF). Growing evidence suggests that the use of ICE improves procedural safety and facilitates radiofrequency and cryoballoon AF ablation. ICE-guided catheter ablation is associated with reduced procedural duration and fluoroscopy use. Recent studies have examined the role of ICE in guiding novel ablation techniques, such as pulsed field ablation. Finally, the use of ICE allows for early detection and timely management of potentially serious procedural complications. Intracardiac echocardiography offers significant advantages during AF ablation procedures and its use should be encouraged to improve procedural safety and efficacy.

Non-invasive versus arterial pressure monitoring in the pre-hospital critical care environment: a paired comparison of concurrently recorded measurements

BackgroundBlood pressure monitoring is important in the pre-hospital management of critically ill patients. Non-invasive blood pressure (NIBP) measurements are commonly used but the accuracy of standard oscillometric cuff devices may be affected by extremes of physiology and adverse conditions (e.g. vibration) during transport. This study aimed to quantify the accuracy of NIBP measurements amongst patients requiring pre-hospital critical care.MethodsA retrospective cohort study was undertaken using data from patients treated by a pre-hospital critical team between 1st May 2020 and 30th April 2023 that had NIBP measured concurrently with invasive blood pressure (IBP) arterial manometry. An acceptable difference was determined a priori to be < 20mmHg for systolic blood pressure (SBP) and diastolic blood pressure (DBP), and < 10mmHg for mean arterial pressure (MAP). The primary outcome was “pairwise agreement”, i.e. the proportion of paired observations that fell within this range of acceptability. Bland-Altman plots were constructed together with 95% limits of agreement to visualise differences between pairs of data. Associations with patient age, reason for critical care, transport status, haemodynamic shock, severe hypertension, and arterial catheter position were explored in univariate analyses and by fitting multivariable logistic regression models.ResultsThere were 2,359 paired measurements from 221 individual patients with a median age of 57. The most frequent reason for transport was cardiac arrest (79, 35.7%). Bland-Altman analyses suggested unacceptably wide limits of agreement with NIBP overestimating both SBP and MAP during hypotension and underestimating these values during hypertension. Haemodynamic shock (SBP < 90mmHg) was independently associated with reduced pairwise agreement for SBP (adjusted odds ratio [aOR] 0.52, 95% CI 0.35 to 0.77), DBP (aOR 0.65, 95% CI 0.42 to 0.99) and MAP (aOR 0.53, 95% CI 0.36 to 0.78) and severe hypertension (SBP > 160mmHg) with reduced pairwise agreement for SBP (aOR 0.17, 95% CI 0.11 to 0.27). There was no association between patient transport and agreement between the methods for SBP, DBP, or MAP.ConclusionsNon-invasive blood pressure measurements are often inaccurate in the pre-hospital critical care setting, particularly in patients with haemodynamic instability. Clinicians should be cautious when interpreting NIBP measurements and consider direct arterial pressure monitoring when circumstances allow.

Endovascular thrombectomy first-pass reperfusion and ancillary device placement

BackgroundRecent randomized trials have demonstrated the efficacy of mechanical thrombectomy in treating acute ischemic stroke, however, further research is required to optimize this technique. We aimed to evaluate the impact...

Detection and position evaluation of chest percutaneous drainage catheter on chest radiographs using deep learning.

This study aimed to develop an algorithm for the automatic detecting chest percutaneous catheter drainage (PCD) and evaluating catheter positions on chest radiographs using deep learning. This retrospective study included 1,217 chest radiographs (proper positioned: 937; malpositioned: 280) from a total of 960 patients underwent chest PCD from October 2017 to February 2023. The tip location of the chest PCD was annotated using bounding boxes and classified as proper positioned and malpositioned. The radiographs were randomly allocated into the training, validation sets (total: 1,094 radiographs; proper positioned: 853 radiographs; malpositioned: 241 radiographs), and test datasets (total: 123 radiographs; proper positioned: 84 radiographs; malpositioned: 39 radiographs). The selected AI model was used to detect the catheter tip of chest PCD and evaluate the catheter's position using the test dataset to distinguish between properly positioned and malpositioned cases. Its performance in detecting the catheter and assessing its position on chest radiographs was evaluated by per radiographs and per instances. The association between the position and function of the catheter during chest PCD was evaluated. In per chest radiographs, the selected model's accuracy was 0.88. The sensitivity and specificity were 0.86 and 0.92, respectively. In per instance, the selected model's the mean Average Precision 50 (mAP50) was 0.86. The precision and recall were 0.90 and 0.79 respectively. Regarding the association between the position and function of the catheter during chest PCD, its sensitivity and specificity were 0.93 and 0.95, respectively. The artificial intelligence model for the automatic detection and evaluation of catheter position during chest PCD on chest radiographs demonstrated acceptable diagnostic performance and could assist radiologists and clinicians in the early detection of catheter malposition and malfunction during chest percutaneous catheter drainage.

Feasibility of transthoracic echocardiographic guidance for multicatheter electrophysiological mapping studies in horses.

Improved characterization of arrhythmias is based on minimally invasive catheterizations. However, these catheterizations have been poorly explored in horses because apart from 3-dimensional (3D) mapping systems, continuous guidance of the catheter's position with adequate detail is difficult using current imaging modalities. Position multiple electrophysiology catheters simultaneously at predetermined strategical positions in the heart using transthoracic echocardiographic guidance. Eight adult healthy horses. Observational study. Two electrophysiological studies were performed: 1 procedure with catheters positioned in the right heart in the standing sedated horse and 1 procedure under general anesthesia with catheters positioned in the left heart. Except for the coronary sinus catheter, each catheter positioning was simultaneously guided by right-parasternal transthoracic echocardiography and 3D electro-anatomical mapping. For each catheter position, a central imaging plane was taken as the starting point, after which the imaging probe was shifted, rotated, and angulated to visualize the catheter over its entire length, including its distal electrode. Catheter positionings in the right heart and left ventricle were successfully guided in the majority of the horses whereas catheter positionings in the left atrium, and especially the pulmonary veins, were challenging to guide echocardiographically. Ultrasound guidance of catheters to specific positions useful for electrophysiological mapping was feasible in the right heart and left ventricle but challenging for the left atrium. This approach creates a perspective for minimally invasive arrhythmia diagnosis without the need for a 3D mapping system. Left parasternal views and intracardiac echocardiography might provide better guidance for left atrial positions.

Dosimetric evaluation of adaptive planning for five-fraction gynecologic template-based interstitial brachytherapy

Purpose: The purpose of this work was to evaluate whether inter-fraction imaging and replanning enhance treatment delivery adherence to clinical planning objectives in the context of a 5-fraction template-based interstitial brachytherapy (TISB) approach for gynecologic cancer treatment. Methods and Materials: This retrospective study analyzed nineteen patients who underwent five fractions of interstitial brachytherapy over three days using the Syed-Neblett template. A verification CT scan was acquired for applicator assessment and reviewed by a radiation oncologist and medical physicist before each fraction. Eleven patients required replanning at least once during the treatment course. Replanning on the verification CT scan consisted of generating new target and organ-at-risk contours, digitizing catheter positions, and optimizing source dwell times to meet planning objectives. Dwell times and positions from the initial treatment plan were evaluated on the new contours to assess the dose that would have been delivered without replanning (non-adapted). Significance of non-adapted versus adapted dose differences were evaluated using a two-sided Wilcoxon sum rank test. Results: The average (min, max) change in dose (Gy) between the clinically delivered plans and the non-adapted plans were HR-CTV D90%: -6.5 (-0.6, -15.1), HR-CTV D98%: -6.5 (-0.4, -12.6), Bladder D2cc: -0.5 (0.0, -2.8), Bowel D2cc: -0.8 (0.0, -3.2), Rectum D2cc: -1.1 (0.0, -11.5), Sigmoid D2cc: -1.4 (-0.1, -5.4). Dosimetric changes in HR-CTV coverage were significantly improved with replanning while organ-at-risk differences were nonsignificant (p>0.05). Fraction 3 was the most common fraction indicated for replanning. Conclusions: Replanning template-based interstitial brachytherapy can improve target coverage and adherence to planning goals.

Effective protocol for continuous pericapsular nerve group block in femur fracture patients undergoing hip surgery: two case reports

Pericapsular nerve group (PENG) block was introduced as an effective way to control postoperative pain in patients who have undergone hip surgery. Therefore, we would like to discuss how to perform PENG block accurately on the basis of two cases, both of which involved hip fracture patients. Ultrasound-guided continuous PENG block was performed, and postoperative pain was adequately controlled in both cases. To mount the catheter in the correct position, it should be inserted after the needle enters at the lowest angle possible. If it is confirmed that the psoas tendon is pushed upward without an increase in injection pressure during drug injection, an accurate continuous PENG block has been achieved. We also analyzed fluoroscopic images to determine how the drug spread, and we observed that the drug spread around the hip capsule along the iliacus and psoas muscle.