Leadless pacemaker implantation via the internal jugular vein.

AIMS: Leadless pacemaker therapy was introduced to overcome lead- and pocket-related complications in conventional transvenous pacemaker systems. Implantation via the femoral vein, however, may not always be feasible. The aim of this study was to evaluate leadless pacemaker implantation using a jugular vein approach and compare it to the standard implantation via the femoral vein. METHODS AND RESULTS: The records of the first consecutive 100 patients undergoing Micra™ leadless pacemaker implantation via the right internal jugular vein from two centres were included in this study. Peri-procedural safety and efficacy of the jugular approach were compared to the first 100 patients using a femoral implantation approach at the University Hospital Zurich. One hundred patients underwent successful implantation of a leadless pacemaker via the internal jugular vein (mean age, 81.18 ± 8.29, 60% males). Mean procedure time was 35.63 ± 10.29 min with a mean fluoroscopy time of 4.66 ± 5.16 min. The device was positioned at the inferior septum in 25 patients, at the high septum in 24 patients, and mid-septum in 51 patients. The mean pacing threshold was 0.56 ± 0.35 V at 0.24 ms pulse width with a sensed amplitude of 10.0 ± 4.4 mV. At follow-up, electrical parameters remained stable in all patients. Compared with femoral implantation, patients undergoing the jugular approach were of similar age and had similar comorbidities. Mean procedure (48.9 ± 21.0 min) and fluoroscopy times (7.7 ± 7.8 min, both P < 0.01) were shorter compared to the femoral approach. Electrical parameters were similar between the two approaches. There were only two complications during jugular veinous implantations (1 pericardial effusion and 1 dislocation), compared to 16 complications using the femoral approach (1 pericardial effusion, 2 femoral artery injuries, and 13 major groin haematomas). CONCLUSION: The jugular approach may represent a safe and efficient alternative to femoral implantation of the Micra leadless pacemaker.

Iatrogenic vertebral artery injury during catheter ablation treated using coil embolization.

The internal jugular vein (IJV) is occasionally used for blood access during catheter ablation. Additionally, accidental injury of the vertebral artery during an IJV puncture is a rare complication that can result in catastrophic events, such as death. However, vascular access complications cannot be completely prevented despite the introduction of ultrasound-guided punctures. Here, we present a case of a patient with symptomatic paroxysmal atrial fibrillation that required catheter ablation.

Central venous catheter tip misplacement: A multicentre cohort study of 8556 thoracocervical central venous catheterisations.

BACKGROUND: There is a paucity of data on the incidence of central venous catheter tip misplacements after the implementation of ultrasound guidance during insertion. The aims of the present study were to determine the incidence of tip misplacements and to identify independent variables associated with tip misplacement. METHODS: All jugular and subclavian central venous catheter insertions in patients ≥16 years with a post-procedural chest radiography at four hospitals were included. Each case was reviewed for relevant catheter data and radiologic evaluations of chest radiographies. Tip misplacements were classified as 'any tip misplacement', 'minor tip misplacement' or 'major tip misplacement'. Multivariable logistic regression analyses were used to investigate associations between predefined independent variables and tip misplacements. RESULTS: A total of 8556 central venous catheter insertions in 5587 patients were included. Real-time ultrasound guidance was used in 91% of all insertions. Any tip misplacement occurred (95% confidence interval) in 3.7 (3.3-4.1)% of the catheterisations, and 2.1 (1.8-2.4)% were classified as major tip misplacements. The multivariable logistic regression analyses showed that female patient gender, subclavian vein insertions, number of skin punctures and limited operator experience were associated with a higher risk of major tip misplacement, whereas increasing age and height were associated with a lower risk. CONCLUSIONS: In this large prospective multicentre cohort study, performed in the ultrasound-guided era, we demonstrated the incidence of tip misplacements to be 3.7 (3.3-4.1)%. Right internal jugular vein catheterisation had the lowest incidence of both minor and major tip misplacement.

Jugular Foramen Paragangliomas.

Paragangliomas are the most common tumors at jugular foramen and pose a great surgical challenge. Careful clinical history and physical examination must be performed to adequately evaluate neurological deficits and its chronologic evolution, also to delineate an overview of the patient performance status. Complete imaging evaluation including MRI and CT scans should be performed, and angiography is a must to depict tumor blood supply and sigmoid sinus/internal jugular vein patency. Screening for multifocal paragangliomas is advisable, with a whole-body imaging. Laboratory investigation of endocrine function of the tumor is necessary, and adrenergic tumors may be associated with synchronous lesions. Preoperative prepare with alpha-blockage is advisable in norepinephrine/epinephrine-secreting tumors; however, it is not advisable in exclusively dopamine-secreting neoplasms. Best surgical candidates are young otherwise healthy patients with smaller lesions; however, treatment should be individualized each case. Variations of infratemporal fossa approach are employed depending on extensions of the mass. Regarding facial nerve management, we avoid to expose or reroute it if there is preoperative function preservation and prefer to work around facial canal in way of a fallopian bridge technique. If there is preoperative facial nerve compromise, the mastoid segment of the nerve is exposed, and it may be grafted if invaded or just decompressed. A key point is to preserve the anteromedial wall of internal jugular vein if there is preoperative preservation of lower cranial nerves. Careful multilayer closure is essential to avoid at most cerebrospinal fluid leakage. Residual tumors may be reoperated if growing and presenting mass effect or be candidate for adjuvant stereotactic radiosurgery.

Severe cervical hematoma following central venous puncture under ultrasound guidance in a patient with acute myeloid leukemia: a rare case report.

We report the case of a 56-year-old male diagnosed with acute myeloid leukemia who developed a severe cervical hematoma following an ultrasound-guided right internal jugular vein catheterization. Despite receiving platelet transfusions prior to the procedure, the patient experienced progressive hematoma enlargement, leading to respiratory distress. Further investigations, including carotid Computed Tomography Angiography (CTA), ruled out arterial injury, but thromboelastography revealed severe coagulation dysfunction. The patient subsequently developed cerebral hemorrhage and died despite intensive care interventions.

New Noninvasive Method for the Assessment of Central Venous Oxygen Saturations in Critically Ill Patients.

OBJECTIVES: To compare noninvasive external jugular vein oxygen saturations (SjvO2) and central venous oxygen saturation (ScvO2) from a blood sample in patients admitted to the intensive care unit. DESIGN: A prospective, comparative, monocentric clinical trial design was used. SETTING: The study was performed in the Department of Anaesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University Hospitals of Geneva (Switzerland). PARTICIPANTS: A total of 79 patients were enrolled; patients with confirmed COVID-19 infection requiring invasive mechanical ventilation (patients with COVID-19, n = 36) and patients after liver transplantation (posttransplant patients, n = 43). INTERVENTIONS: Simultaneous measurement of SjvO2 by near-infrared spectroscopy and ScvO2 from central venous blood samples using a blood gas analyzer in stable hemodynamic conditions. MEASUREMENTS AND MAIN RESULTS: A strong linear correlation was evidenced in both the COVID-19 and posttransplant patient groups between the 2 modalities. The Bland-Altman analysis showed low bias in accordance with low percentage error in both groups (0.57% and 8.09% for patients with COVID-19; 0.00% and 13.72% for posttransplant patients). CONCLUSIONS: Central venous oxygen saturation can be estimated reasonably by the continuous noninvasive measurement of SjvO2 using near-infrared spectroscopy.

Evaluation of the Efficacy of a Novel Dermatotomy Device for Central Venous Cannulation.

OBJECTIVE: To test the effectiveness of a novel wire-guided scalpel (Guideblade) to create a precise dermatotomy incision for central venous catheter (CVC) insertion. DESIGN: Prospective, nonrandomized interventional study. SETTING: Stanford University, single-center teaching hospital. PARTICIPANTS: Cardiac and vascular surgical patients (n = 100) with planned CVC insertion for operation. INTERVENTIONS: A wire-guided scalpel was used during CVC insertion. RESULTS: A total of 188 CVCs were performed successfully with a wire-guided scalpel without the need for additional equipment in 100 patients, and 94% of CVCs were accomplished with only a single dermatotomy attempt. "No bleeding" or "minimal bleeding" at the insertion site was observed in 90% of patients 30 minutes after insertion and 80.7% at the conclusion of surgery. CONCLUSION: The wire-guided scalpel was effective in performing dermatotomy for CVC with a 100% success rate and a very high first-attempt rate. The wire-guided scalpel may decrease bleeding at the CVC insertion site.

Eagle jugular syndrome accompanied by de novo brainstem cavernous malformation: a case-based systematic review.

BACKGROUND: Eagle jugular syndrome (EJS), recently identified as a cause of cerebrovascular disease (CVD) due to venous obstruction by an elongated styloid process (SP), is reported here alongside a case of concurrent de novo cerebral cavernous malformation (CCM). This study aims to explore the potential causal relationship between EJS and de novo CCM through a comprehensive literature review. METHOD: Systematic literature reviews, spanning from 1995 to 2023, focused on EJS cases with definitive signs and symptoms and de novo CCM cases with detailed clinical characteristics. Data on the pathophysiology and clinical manifestations of EJS, as well as potential risk factors preceding de novo CCM, were collected to assess the relationship between the two conditions. RESULT: Among 14 patients from 11 articles on EJS, the most common presentation was increased intracranial hypertension (IIH), observed in 10 patients (71.4%), followed by dural sinus thrombosis in four patients (28.6%). In contrast, 30 patients from 28 articles were identified with de novo CCM, involving 37 lesions. In these cases, 13 patients developed CCM subsequent to developmental venous anomalies (43%), seven following dural arteriovenous fistula (dAVF) (23%), and two after sinus thrombosis (6%). In a specific case of de novo brainstem CCM, the development of an enlarged condylar emissary vein, indicative of venous congestion due to IJV compression by the elongated SP, was noted before the emergence of CCM. CONCLUSION: This study underscores that venous congestion, a primary result of symptomatic EJS, might lead to the development of de novo CCM. Thus, EJS could potentially be an indicator of CCM development. Further epidemiological and pathophysiological investigations focusing on venous circulation are necessary to clarify the causal relationship between EJS and CCM.

A rare hemodialysis vascular access complication-Internal jugular vein reflux.

Hemodialysis (HD) arteriovenous fistulas commonly present with late vascular access complications, but are rarely in association with internal jugular vein (IJV) reflux. We reported two patients who had severe and mild IJV reflux, respectively. Case 1 was a 48-year-old male with end-stage renal disease (ESRD) who had been treated with HD for 5 years. He presented with persistent headaches, nausea, and vomiting. Combined with all the examinations, it was revealed severe IJV reflux, brachiocephalic vein stenosis, high-flow vascular access, and IJV valve dysfunction. Case 2 was a 59-year-old female with ESRD who had constructed an AVF for 4 months and had been on HD for only 1 day. She presented with dizziness and nausea after the first hemodialysis and duplex ultrasonography showed slightly continuous IJV reflux, high-flow vascular access, and IJV valve dysfunction. Furthermore, we reviewed 16 case reports to identify the characteristics of IJV reflux in HD patients. IJV reflux in HD patients may be caused by high-flow access, central venous stenosis or occlusion, and valve dysfunction. Severe IJV reflux can develop neurological symptoms secondary to intracranial venous reflux in this article. Etiological treatment is helpful for these patients, but there is a risk of recurrence.

Computed tomographic characteristics of anatomical variations of external and internal jugular veins in dogs.

The external jugular vein (EJV) has been commonly used for clinical procedures in veterinary medicine, while the internal jugular vein (IJV) has been used mainly for research. Limited literature regarding anatomical variants in both EJV and IJV is available. The objectives of this descriptive retrospective study were to identify the number of dogs with variations of the jugular veins in canine patients undergoing CT of the head and neck and characterize these variations. Of 1000 dogs, 193 dogs (19.3%) had anatomical variations. Six types of anatomical variations were identified. The most common Type I was the absence of the linguofacial vein (72.0%, n = 139), with the lingual, facial, and maxillary veins entering the EJV at a common branching point. Type II described a variable course of the EJV and IJV, which in some dogs resulted in the absence of the EJV (14.0%, n = 27). Type III was a variable anastomotic loop formed by the linguofacial or maxillary vein cranial or at the junction of the EJV (4.2%, n = 8). In Type IV, the EJV was either suspected to be aplastic or markedly reduced in diameter compared with the contralateral side just distal to its formation (3.6%, n = 7). Type V was found in only six dogs (3.1%) with unilateral differences in the diameter of the IJV. Six of 193 dogs had a combination of more than one variation (Type VI, 3.1%). Type I was significantly observed more frequently in meso- and dolichocephalic breeds. Type II was significantly observed more frequently in brachycephalic breeds.

Anatomical variations in the superficial venous system of the neck: an image-based study using contrast-enhanced computed tomography.

PURPOSE: The superficial venous system (SVS) of the neck receives blood from the face and oral cavity. The SVS comprises the anterior jugular vein (AJV), external jugular vein (EJV), and facial vein (FV). Comprehensive knowledge of the normal anatomy and potential variations in the venous system is valuable in surgical and radiological procedures. This study aimed to update the anatomic knowledge of the SVS using a radiographic approach, which is a beneficial data source in clinical practice. METHODS: Contrast-enhanced computed tomography images of the neck of patients with head and neck cancer treated between 2017 and 2020 were retrospectively evaluated. Each side of the neck was counted separately. A total of 302 necks of 151 patients were enrolled in this study. RESULTS: The medial AJV was absent in 49.7% (75/151) of the patients on the left side, which was significantly greater than the 19.2% (29/151) on the right (p < 0.001). The left AJV drained into the right venous system in 6.6% (10/151) of the necks. In 48.3% (146/302) of the necks, the FV did not flow into the internal jugular vein but rather into the EJV or AJV; these findings were significantly more frequent than those reported in previous studies. The diameters of the veins were significantly larger when they received blood from the FV than when they were not connected to the FV. CONCLUSION: These findings indicate that the AJV has a rightward preference during its course. The course of the FV is diverse and affects the diameter of connected veins.

An unilateral double fenestration of the right external jugular vein: a rare variant.

OBJECTIVES: This report presents a rare anatomical variation, double fenestration of the External jugular vein on the right side. MATERIALS AND METHODS: During the routine dissection of a male cadaver aged 60 years, we observed a unilateral large double fenestration of the External jugular vein on the right side. RESULTS: After its formation from the posterior division of the retromandibular and posterior auricular veins, External jugular vein descended in the posterior triangle of neck. Here, it divided into medial, intermediate, and lateral veins that united again before draining into the subclavian vein. Lateral vein was the largest (7.2 cm) and intermediate and medial veins were measuring 6.4 cm each. Two large fenestrations, measuring 5.8 cm each, arranged like a "double bubble" were seen in the External jugular vein extending from fourth to sixth cervical (C4 to C6) vertebrae. The medial branch of supraclavicular nerve was seen passing superficial to the distal part of External jugular vein. On the left side, the course of External jugular vein showed a standard pattern. CONCLUSION: Surgeons must be acquainted with the varied anatomy of the superficial neck veins to prevent major bleeding during operative procedures, including carotid endarterectomy, flap operations, & central venous catheterisation.

A jugular venous compression adjunct for surgical excision of distensible orbital venous malformations.

PURPOSE: Orbital venous malformations (VM) pose challenges in complete resection due to indistinct borders and bleeding proclivity. Current methods for aiding surgical excision of distensible orbital venous malformations are inadequate. We investigated whether external neck compression could facilitate intraoperative distension of venous orbital lesions during surgical excision in patients diagnosed with VM. METHODS: Eighteen patients (8 males and 10 females) diagnosed with distensible venous anomalies were enrolled. Neck compression technology, was employed to distend the lesions before puncture embolization using n-butyl-2-cyanoacrylate glue under general anesthesia. The surgical process, along with preoperative to postoperative changes in ocular symptoms, were recorded. RESULTS: The average surgical duration was 95 min. A mean of 3.41 ml surgical glue was used for embolization. The compression belt maintained pressure at 35-40 mmHg. Total lesion resection was achieved in 12 patients, with 6 patients undergoing subtotal removal not requiring supplementary surgery. Symptoms were entirely alleviated in 17 patients, and signs of distensible lesions during the Valsalva maneuver were absent. One patient underwent secondary surgery for residual eyelid lesions. Minor complications included mild ocular movement restriction, residual subcutaneous induration, transiently increased orbital pressure, and lower lid ectropion in four, three, four, and one patient, respectively. Three patients experienced a mild post-operative visual acuity decrease, although none experienced vision loss. CONCLUSIONS: Direct orbital embolization aided by a jugular vein compression device is safe and demonstrates satisfactory outcomes in orbital varicose vein treatment.

A haemodialysis catheter misplaced due to central venous stenosis: A case report.

Chronic kidney disease has become a significant global health issue, with some individuals progressing to endstage renal disease (ESRD) and requiring renal replacement therapy. For ESRD patients undergoing haemodialysis, the first step is to establish vascular access. In emergency situations, inserting a haemodialysis catheter (HDC) into the central vein is often the most appropriate approach; the right internal jugular vein (IJV) is considered the optimal site for catheterisation. However, catheter placement in the right IJV can sometimes lead to inadvertent entry into an abnormal position. Herein, we present a unique case in which the tip of the HDC was noted to have misplaced into the left IJV due to the patient's multiple central venous stenosis (CVS). This case highlights the clinical manifestation of HDC misplacement, with CVS being the underlying cause. Therefore, healthcare providers should pay adequate attention to CVS.

Anatomical Variations of the Jugular Bulb: A Critical and Comprehensive Review.

Background and Objectives: The jugular bulb (JB) is the uppermost part of the internal jugular vein receiving the sigmoid sinus. The aim of the present research is to aid the comprehension of the JB, its abnormalities, and surrounding structures for improving both academic and surgical awareness. Materials and Methods: Various studies on this topic were critically reviewed. Cone-beam CT scans and CT and MR angiograms were used to demonstrate each type of the discussed variations. Results: Variations in the JB anatomy were thoroughly documented: high JB, dehiscent JB, hypoplasia and hyperplasia, and diverticula of the JB, as they have significant clinical implications, particularly in the context of otological and neuro-otological surgery, skull base pathology, and diagnostic imaging. Definitions and critical arguments were also specified to clarify existing literature. Additionally, we present a case report illustrating a high and dehiscent JB, an anatomical variation of clinical interest due to its potential for misdiagnosis as a glomus tumor. Another case describes a dehiscent JB with a hypotympanic air cell protruding into it, further highlighting the variability of this condition. Conclusions: It is necessary to proceed with caution when observing abnormal morphological characteristics of the JB. Preoperative assessment of each case is essential for optimal outcomes.

Anatomical variations in the course of spinal accessory nerve in the neck triangles: A descriptive study.

BACKGROUND: Spinal Accessory Nerve (SAN), which innervates the sternocleidomastoid (SCM) and trapezius muscles, is closely related to the internal jugular vein (IJV) in the anterior triangle of the neck and passes superficially in the posterior triangle. Injury to SAN is a major complication of level II neck dissection, leading to shoulder syndrome. The present study aims to assess the course and its relation to the SCM muscle and IJV in the Tamil ethnolinguistic groups in South India. METHODS AND MATERIALS: The anterior and posterior triangles of the neck were dissected in 28 formalin-fixed adult cadavers. The course of the SAN and the entry and exit points of SAN along the SCM muscle were assessed using the mastoid process as the reference. Recorded data was analyzed using SPSS software. RESULTS: The SAN was anteriorly related to the IJV in 58.73%, posteriorly in 37.5%, and pierced through the IJV in 3.57% of the specimens. The entry and exit points of SAN from the mastoid process were 37.86±7.26mm and 48.55±8.22mm, respectively. In 86.67% of the cases, the SAN traversed through the SCM muscle, and in 13.33%, it was deep to the SCM. CONCLUSION: The present study reports that the SAN is variable in its course, and relation to SCM and IJV. Knowledge about the variant anatomy of the SAN in the triangles of the neck is important and it aids surgeons to prevent iatrogenic injuries to SAN or IJV and enhance surgical safety in neck procedures.

Correlation of Internal Jugular Vein and Inferior Vena Cava Collapsibility Index with Direct Central Venous Pressure Measurement in Critically-ill Patients: An Observational Study.

Background and aims: Prompt assessments and quick replacement of intravascular fluid are critical steps to resuscitate hypovolemic patients. Intravascular volume assessment by direct central venous pressure (CVP) measurement is an invasive, time-consuming, and labor-intensive procedure. Nowadays, bedside ultrasound-guided volume assessment of the internal jugular vein (IJV) or inferior vena cava (IVC) is commonly employed as a proxy for direct CVP.Therefore, we examined the strength of association between CVP and collapsibility index (CI) of the IJV and IVC for evaluating the volume status of critically ill patients. Methods: Bedside USG-guided A-P diameter and cross-sectional area of the right IJV and IVC were measured, and their corresponding collapsibility indices were deduced. The results of the IJV and IVC indices were correlated with CVP. Results: About 60 out of 70 enrolled patients were analyzed. The baseline clinical parameters of patients are shown in Table 1. For CSA and AP diameter, the correlations between CVP and IJV-CI at 0° were r = -0.107 (p = 0.001) and r = -0.092 (p = 0.001). Correlations between CVP and IJV-CI at 30° for CSA and diameter, however, were (r = -0.109, p = 0.001) and (r = -0.117, p = 0.001), respectively. Table 2 depicts the correlation between CVP and IVC-CI r = -0.503, p = 0.001 for CSA and r = -0.452, p = 0.001 for diameter. Conclusion: The IVC and IJV collapsibility indices can be used in place of invasive CVP monitoring to assess fluid status in critically ill patients. How to cite this article: Kumar A, Bharti AK, Hussain M, Kumar S, Kumar A. Correlation of Internal Jugular Vein and Inferior Vena Cava Collapsibility Index with Direct Central Venous Pressure Measurement in Critically-ill Patients: An Observational Study. Indian J Crit Care Med 2024;28(6):595-600.

Prognostic Value of Jugular Venous Diameters and Compliance in Patients with Exacerbation of Chronic Obstructive Pulmonary Disease.

Background: Chronic obstructive pulmonary disease (COPD) exacerbations constitute a significant proportion of patients presenting to the emergency department (ED). It has been suggested that measurement of jugular venous diameter and compliance may have prognostic value in patients with heart failure. We hypothesized that these measurements may also be valuable in patients with advanced COPD. Methods: This study was a single-center, prospective, and cross-sectional study conducted in a university hospital between November 2020 and November 2021. In the study, internal jugular vein (IJV) diameters (inspiration, forced expiration, and rest) and jugular venous compliance were measured with ultrasound in patients who presented to the ED with COPD exacerbation. One month later, data about mortality, intensive care unit (ICU) admission, and any hospitalization were obtained and evaluated together with a range of laboratory parameters. Results: Data from a total of 93 patients were analyzed. Of these, 17 (18.2%) died, 19 (20.4%) were admitted to the ICU, and 36 (38.7%) were hospitalized at the end of the 1-month period. Consequently, a total of 44 patients (47.3%) were in the good outcome group and 49 patients (52.7%) were in the poor outcome group. In terms of mortality, inspiratory IJV diameter was 5.6 ± 2.9 mm in the survived group (n = 76) and 7.6 ± 3.9 mm in the deceased group (n = 17) (P = 0.031). There was no difference between the venous compliance values and other diameter measurements of the patients. In the analysis performed with the subgroup with high N-terminal prohormone brain natriuretic peptide values, it was shown that both resting and inspiration diameter measurements were higher in the group with poor outcomes. Conclusion: There was no difference between the jugular vein compliance values in terms of mortality in patients admitted to the ED with COPD exacerbation. However, these measurements may have prognostic value in patients with COPD exacerbations complicated by heart failure.

Assessment of venous pressure by compression sonography of the internal jugular vein during 3 days of bed rest.

Compression sonography has been proposed as a method for non-invasive measurement of venous pressures during spaceflight, but initial reports of venous pressure measured by compression ultrasound conflict with prior reports of invasively measured central venous pressure (CVP). The aim of this study is to determine the agreement of compression sonography of the internal jugular vein (IJVP) with invasive measures of CVP over a range of pressures relevant to microgravity exposure. Ten healthy volunteers (18-55 years, five female) completed two 3-day sessions of supine bed rest to simulate microgravity. IJVP and CVP were measured in the seated position, and in the supine position throughout 3 days of bed rest. The range of CVP recorded was in line with previous reports of CVP during changes in posture on Earth and in microgravity. The correlation between IJVP and CVP was poor when measured during spontaneous breathing (r = 0.29; R2  = 0.09; P = 0.0002; standard error of the estimate (SEE) = 3.0 mmHg) or end-expiration CVP (CVPEE ; r = 0.19; R2  = 0.04; P = 0.121; SEE = 3.0 mmHg). There was a modest correlation between the change in CVP and the change in IJVP for both spontaneous ΔCVP (r = 0.49; R2  = 0.24; P < 0.0001) and ΔCVPEE (r = 0.58; R2  = 0.34; P < 0.0001). Bland-Altman analysis of IJVP revealed a large positive bias compared to spontaneous breathing CVP (3.6 mmHg; SD = 4.0; CV = 85%; P < 0.0001) and CVPEE (3.6 mmHg; SD = 4.2; CV = 84%; P < 0.0001). Assessment of absolute IJVP via compression sonography correlated poorly with direct measurements of CVP by invasive catheterization over a range of venous pressures that are physiologically relevant to spaceflight. However, compression sonography showed modest utility for tracking changes in venous pressure over time. NEW FINDINGS: What is the central question of this study? Compression sonography has been proposed as a novel method for non-invasive measurement of venous pressures during spaceflight. However, the accuracy has not yet been confirmed in the range of CVP experienced by astronauts during spaceflight. What is the main finding and its importance? Our data show that compression sonography of the internal jugular vein correlates poorly with direct measurement of central venous pressures in a range that is physiologically relevant to spaceflight. However, compression sonography showed modest utility for tracking changes in venous pressure over time.

Impact of the insertion site of central venous catheters on central venous catheter-related bloodstream infections in patients with cancer: results from a large prospective registry.

PURPOSE: Overall, insertion of central venous catheter (CVC) into femoral veins (FV) has been shown to be associated with a higher risk of infection compared with subclavian and internal jugular (IJV/SCV) CVC, but no data are available on the impact of the FV insertion site on the CVC-related bloodstream infections (CRBSI) risk in patients with cancer. The objective of the study is to compare CRBSI rates and incidences of FV with those of internal jugular and subclavian vein (IJV/SCV CVC) as observed in the prospective SECRECY registry. METHODS: SECRECY is an ongoing observational, prospective, clinical CRBSI registry active in six departments of hematology/oncology in Germany. Each case of FV CVC was matched at a ratio of 1:1 to a case with IJV/SCV CVC. The propensity score was estimated using a multivariable logistic regression model adjusting for age, sex, cancer type, and duration of indwelling catheter. RESULTS: Of 4268 CVCs included in this analysis, 52 (1.2%) were inserted into the FV and 4216 (98.8%) into the IJV/SCV. 52 cases of FV CVC were matched with 52 IJV/SCV CVC. There was no significant difference in the CRBSI rate (3.8% vs. 9.6%), the CRBSI incidence (5.7 vs. 14.2/1000 CVC days), and the median CVC time (5.5 vs. 5 days) between the FV and the IJV/SCV group. CONCLUSION: Based on this data, inserting FV CVCs in patients with cancer does, at least in the short-term, not appear to be associated with an increased risk of CRBSI as compared to IJV/SCV CVC.