Internal Jugular Venous Research Articles

Aveir VR, retrievable leadless pacing in the young.

Successful implantations of the Aveir VR, have been effectively demonstrated in adults; however, there remain limited reports supporting safe and feasible implantation of the Aveir VR in the young population. Retrospective, observational study of Aveir VR implantation of young patients (≦21 years old) at UC Davis Medical Center from November 2022 to January 2024 via the internal jugular or femoral vein implantation approaches. Indications for pacing, patient demographics, pacing thresholds and longevity were reported at the time of implantation and last follow-up. A total of 10 patients received the Aveir VR with a median age of years (IQR 12.5-17) and median weight of 50.8kg (IQR 44.6-60.9) kg. The majority were male (80%). Aveir VR leadless pacemaker occurred via internal jugular venous (90%) or femoral venous (10%) approaches. Indications for placement were intermittent complete heart block (60%) and sinus pauses (40%). Adequate impedance, sensing and thresholds were maintained from implantation to a median follow-up of 9 months. Predicted pacemaker longevity at follow-up median was 23.8 years. There were no complications in any of the 10 patients. Aveir VR implantation via the internal jugular and femoral veins is feasible in the young patient population with stable pacing parameters at follow-up.

Severe hypoxaemic hypercapnia compounds cerebral oxidative-nitrosative stress during extreme apnoea: Implications for cerebral bioenergetic function.

We examined the extent to which apnoea-induced extremes of oxygen demand/carbon dioxide production impact redox regulation of cerebral bioenergetic function. Ten ultra-elite apnoeists (sixmen and four women) performed two maximal dry apnoeas preceded by normoxic normoventilation, resulting in severe end-apnoea hypoxaemic hypercapnia, and hyperoxic hyperventilation designed to ablate hypoxaemia, resulting in hyperoxaemic hypercapnia. Transcerebral exchange of ascorbate radicals (by electron paramagnetic resonance spectroscopy) and nitric oxide metabolites (by tri-iodide chemiluminescence) were calculated as the product of global cerebral blood flow (by duplex ultrasound) and radial arterial (a) to internal jugular venous (v) concentration gradients. Apnoea duration increased from 306 ± 62s during hypoxaemic hypercapnia to 959 ± 201s in hyperoxaemic hypercapnia (P≤ 0.001). Apnoea generally increased global cerebral blood flow (all P≤ 0.001) but was insufficient to prevent a reduction in the cerebral metabolic rates of oxygen and glucose (P=0.015-0.044). This was associated with a general net cerebral output (v > a) of ascorbate radicals that was greater in hypoxaemic hypercapnia (P=0.046 vs. hyperoxaemic hypercapnia) and coincided with a selective suppression in plasma nitrite uptake (a > v) and global cerebral blood flow (P=0.034 to <0.001 vs. hyperoxaemic hypercapnia), implying reduced consumption and delivery of nitric oxide consistent with elevated cerebral oxidative-nitrosative stress. In contrast, we failed to observe equidirectional gradients consistent with S-nitrosohaemoglobin consumption and plasma S-nitrosothiol delivery during apnoea (all P≥ 0.05). Collectively, these findings highlight a key catalytic role for hypoxaemic hypercapnia in cerebral oxidative-nitrosative stress. KEY POINTS: Local sampling of blood across the cerebral circulation in ultra-elite apnoeists determined the extent to which severe end-apnoea hypoxaemic hypercapnia (prior normoxic normoventilation) and hyperoxaemic hypercapnia (prior hyperoxic hyperventilation) impact free radical-mediated nitric oxide bioavailability and global cerebral bioenergetic function. Apnoea generally increased the net cerebral output of free radicals and suppressed plasma nitrite consumption, thereby reducing delivery of nitric oxide consistent with elevated oxidative-nitrosative stress. The apnoea-induced elevation in global cerebral blood flow was insufficient to prevent a reduction in the cerebral metabolic rates of oxygen and glucose. Cerebral oxidative-nitrosative stress was greater during hypoxaemic hypercapnia compared with hyperoxaemic hypercapnia and coincided with a lower apnoea-induced elevation in global cerebral blood flow, highlighting a key catalytic role for hypoxaemia. This applied model of voluntary human asphyxia might have broader implications for the management and treatment of neurological diseases characterized by extremes of oxygen demand and carbon dioxide production.

Cerebral venous biomarkers and veno-arterial gradients: untapped resources in Alzheimer's disease.

Blood based biomarkers (BBB) derived from forearm veins for estimating brain changes is becoming ubiquitous in Alzheimer's Disease (AD) research and could soon become standard in routine clinical diagnosis. However, there are many peripheral sources of contamination through which concentrations of these metabolites can be raised or lowered after leaving the brain and entering the central venous pool. This raises the issue of potential false conclusions that could lead to erroneous diagnosis or research findings. We propose the use of simultaneous sampling of internal jugular venous and arterial blood to calculate veno-arterial gradient, which can reveal either a surplus or a deficit of metabolites exiting the brain. Methods for sampling internal jugular venous and arterial blood are described along with examples of the use of the veno-arterial gradient in non-AD brain research. Such methods in turn could help better establish the accuracy of forearm venous biomarkers.

High jugular bulb in patients with non-thrombotic internal jugular venous and transverse sinus stenosis: Clues to pathogenesis.

Conventional theories for jugular bulb (JB) formation are insufficient to explain the high proportion of high JB in adult patients. We aimed to study features of high JB in patients with non-thrombotic internal jugular venous stenosis (IJVS) and/or transverse sinus stenosis (TSS) to explore the pathogenesis of high JB formation. We retrospectively enrolled consecutive patients with the diagnosis of non-thrombotic IJVS and/or TSS. The relationship between IJVS and/or TSS and high JB was explored. Logistic regression analysis was performed to identify potential independent risk factors for high JB. A total of 228 patients were included in the final analyses. The proportions of IJVS, dominant-side IJVS, and non-TSS in dominant-side high JB subgroup were higher than those in nondominant-side high JB subgroup (83.3% vs. 62.5%, p < 0.001; 72.2% vs. 18.3%, p < 0.001; 43.5% vs. 29.2%, p = 0.02). Heights of JBs on dominant sides in IJVS subgroup and non-TSS subgroup were higher than those in non-IJVS subgroup and TSS subgroup (12.93 ± 2.57 mm vs. 11.21 ± 2.76 mm, p < 0.001; 12.66 ± 2.71 mm vs. 11.34 ± 2.73 mm, p = 0.003). Multivariate logistic regression indicated an independent association between dominant-side IJVS and dominant-side high JB (odds ratio, 29.40; 95% confidence interval, 11.04-78.30; p < 0.001). IJVS and asymmetric transverse sinus were independently and positively associated with high JB, especially dominant-side IJVS with dominant-side high JB, indicating a potential hemodynamic relationship between IJVS and high JB formation. Conversely, TTS might impede high JB formation.

A child suffering from severe acute respiratory distress syndrome due to multiple trauma was treated with veno-veous extracorporeal membrane oxygenation with the dual lumen cannula: a case report

Veno-veous extracorporeal membrane oxygenation (VV-ECMO) has been widely used in the treatment for severe acute respiratory distress syndrome (ARDS). Up to now, the routine access to establish VV-ECMO involves two-sites single lumen cannula via femoral vein and internal jugular venous in adult and children, while few studies about the dual lumen cannula (DLC) in VV-ECMO implemented in adult and children have been reported. On December 16, 2021, an unconscious child with severe ARDS due to multiple trauma caused by fatal falling from a height was admitted to Taihe Hospital. The initial diagnosis was hemorrhagic shock, bilateral hemopneumothorax, sternal fracture, cavity organ perforation, splenic rupture, and pelvic fracture and severe ARDS. Despite mechanical ventilation, he progressed to refractory hypoxemia and was treated with VV-ECMO after successful DLC placement in the right internal jugular vein by the mobile ECMO team of intensive care unit of the Union Hospital eventually. In addition, he received endoscopic sputum aspiration, prone position ventilation, anti-infection and nutritional treatment. His oxygenation gradually improved and he was successfully weaned from ECMO after 11 days. In this case, DLC simplified the process without any related complications, suggesting that it can be safely and effectively used in the treatment of Child's severe ARDS.

COMPARISON OF ULTRASOUND GUIDED OUT OF PLANE SHORT AXIS METHOD / IN PLANE LONG AXIS METHOD FOR RIGHT INTERNAL JUGULAR VENOUS CANNULATION IN TERTIARY CARE HOSPITAL.

Background Ultrasound (US) guidance for Internal Jugular Venous (IJV) placement is considered gold standard in localization and cannulation, making the procedure safer with less complications. To compare the Aims &amp; Objectives short-axis/out-of-plane (SAX) with the long-axis/in-plane (LAX) technique for US-guided CVC insertion in internal jugular vein in intensive care practice in terms of safety and efcacy. In this Retrospective observa Methods tional study we have enrolled total 232 patients admitted in our tertiary care hospital during June 2016 to June 2020 at NHLMMC, VS &amp; SVP hospital, Ahmedabad, India after taking written informed consent and explaining the procedure to patient &amp; their relatives. Randomisation was done at time of procedure by odd &amp; even numbers put in opaque sealed envelope. There were two groups: Group S which included 116 patients in whom the out of plane short axis SAX technique was performed and Group L which also included 116 patients in whom the in plane LAX technique was performed for US-guided IJV insertion in Right internal jugular vein. The primary outcome was rst-attempt success rate of both the approaches for US-guided vascular catheterization. The secondary outcomes were total success rate, which was dened as successful venous cannulation without complication; cannulation time calculated in seconds; the number of attempts and complications (hematoma and arterial puncture). US-guided venous cannulation was Results successful without complications in 99% patients in group S &amp; 95% in group L. Venous access time, cannulation time, and US imaging time were signicantly lower in the group S than in the group L (P&lt;0.05). Complications in both groups had no statistically signicant difference. Hematoma formation was evident in one patient in group L. Multiple puncture was more in LAX group with no signicant difference. Conclusion: Out of plane SAX approach is better than in plane LAX approach for ultrasound guided IJV cannulation.

Hypoxemia Destabilizes The Neurovascular Unit During Extreme Apnea In Humans

To what extent voluntary asphyxia imposed by static apnea challenges the functional-structural limits of the neurovascular unit (NVU) in humans characterized by extremes of hypertension, hypoxemia and hypercapnia remains unclear. PURPOSE: To document the transcerebral exchange kinetics of NVU-specific proteins during extreme apnea and independent contributory influence of hypoxemia. METHODS: Ten world class breath-hold divers (6♂, 4♀) performed two maximal dry apneas preceded by normoxic normoventilation (NX: severe hypoxemia and hypercapnia) and hyperoxic hyperventilation (HX: absence of hypoxemia with exacerbating hypercapnia) with measurements obtained before and after apnea. Transcerebral exchange of NVU proteins (ELISA, Single Molecule Array) were calculated as the product of global cerebral blood flow (gCBF, duplex ultrasound) and radial arterial to internal jugular venous concentration gradients. RESULTS: Apnea duration increased from 5 m 6 s in NX to 15 m 59 s in HX (P = < 0.001) resulting in marked elevations in gCBF and venous S100B, glial fibrillary acidic protein, ubiquitin carboxy-terminal hydrolase-L1 and total tau (all P < 0.05 vs. baseline). This culminated in net cerebral output reflecting increased blood-brain barrier permeability and neuro-glio-vascular dysfunction that was more pronounced in NX due to more severe systemic and intracranial hypertension (P < 0.05 vs. HX). CONCLUSION: These findings identify the hemodynamic stress to which the apneic brain is exposed, highlighting the critical contribution of hypoxemia and not just hypercapnia to NVU destabilization.

Hypoxemia increases blood-brain barrier permeability during extreme apnea in humans

Voluntary asphyxia imposed by static apnea challenges blood-brain barrier (BBB) integrity in humans through transient extremes of hypertension, hypoxemia and hypercapnia. In the present study, ten ultra-elite breath-hold divers performed two maximal dry apneas preceded by normoxic normoventilation (NX: severe hypoxemia and hypercapnia) and hyperoxic hyperventilation (HX: absence of hypoxemia with exacerbating hypercapnia) with measurements obtained before and immediately after apnea. Transcerebral exchange of NVU proteins (ELISA, Single Molecule Array) were calculated as the product of global cerebral blood flow (gCBF, duplex ultrasound) and radial arterial to internal jugular venous concentration gradients. Apnea duration increased from 5 m 6 s in NX to 15 m 59 s in HX (P = <0.001) resulting in marked elevations in gCBF and venous S100B, glial fibrillary acidic protein, ubiquitin carboxy-terminal hydrolase-L1 and total tau (all P < 0.05 vs. baseline). This culminated in net cerebral output reflecting mildly increased BBB permeability and increased neuronal-gliovascular reactivity that was more pronounced in NX due to more severe systemic and intracranial hypertension (P < 0.05 vs. HX). These findings identify the hemodynamic stress to which the apneic brain is exposed, highlighting the critical contribution of hypoxemia and not just hypercapnia to BBB disruption.

Comparison of three different techniques for internal jugular vein cannulation under real time ultrasound guidance

&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Ultrasound (USG) guided Internal jugular venous (IJV) cannulation is preferred than traditional approach due to increase in success rate, reduction in time taken and attempts of successful cannulation and less complications. The purpose of our study was to observe and compare three different real time 2-dimensional US-guided approaches and to determine which approach improves rate of successful cannulation, decreases complications along with shorter average time taken for the procedure. Primary outcomes of the study were venous access time, catheterization time and success rate. Secondary outcomes were number of patients requiring second attempt and complications observed.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;120 adult patients were randomly divided into three groups according to real time US guided cannulation done with SAX-OP approach, LAX-IP approach and OAX-IP approach. Parameters like venous access time, catheterization time, number of patients requiring second attempt and complications were noted.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;Venous access time was shortest in LAX group 21.84±3.67 seconds which was just significant statistically. Catheterization time was shortest in LAX group 241±123 seconds. Cannulation success rate was highest in LAX group 98% and was statistically significant. Patients requiring second attempt was least in LAX group 2.5%. Posterior IJV wall puncture was observed in 10% patients in SAX group and none in LAX and OAX group which was statistically significant.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; LAX-IP showed better performance in terms of higher cannulation success, lesser average venous access time and catheterization time and lesser complications. On toggling USG probe, both IJV and carotid artery can be differentiated and carotid puncture could be avoided. Hence LAX approach is safer and effective approach.&lt;/p&gt;

Hypoxia ameliorates brain hyperoxia and NAD+ deficiency in a murine model of Leigh syndrome

Leigh syndrome is a severe mitochondrial neurodegenerative disease with no effective treatment. In the Ndufs4−/− mouse model of Leigh syndrome, continuously breathing 11% O2 (hypoxia) prevents neurodegeneration and leads to a dramatic extension (~5-fold) in lifespan. We investigated the effect of hypoxia on the brain metabolism of Ndufs4−/− mice by studying blood gas tensions and metabolite levels in simultaneously sampled arterial and cerebral internal jugular venous (IJV) blood. Relatively healthy Ndufs4−/− and wildtype (WT) mice breathing air until postnatal age ~38 d were compared to Ndufs4−/− and WT mice breathing air until ~38 days old followed by 4-weeks of breathing 11% O2. Compared to WT control mice, Ndufs4−/− mice breathing air have reduced brain O2 consumption as evidenced by an elevated partial pressure of O2 in IJV blood (PijvO2) despite a normal PO2 in arterial blood, and higher lactate/pyruvate (L/P) ratios in IJV plasma revealed by metabolic profiling. In Ndufs4−/− mice, hypoxia treatment normalized the cerebral venous PijvO2 and L/P ratios, and decreased levels of nicotinate in IJV plasma. Brain concentrations of nicotinamide adenine dinucleotide (NAD+) were lower in Ndufs4−/− mice breathing air than in WT mice, but preserved at WT levels with hypoxia treatment. Although mild hypoxia (17% O2) has been shown to be an ineffective therapy for Ndufs4−/− mice, we find that when combined with nicotinic acid supplementation it provides a modest improvement in neurodegeneration and lifespan. Therapies targeting both brain hyperoxia and NAD+ deficiency may hold promise for treating Leigh syndrome.

Comparison of external jugular venous access with internal jugular venous access in pediatric shock

Background: Central venous access is usually preferred over the peripheral venous route when circulatory failure needs inotropes and vasopressors. However, in resource-limited settings with underskilled personnel, it is not feasible always and so patients are being treated with the peripheral venous route with variable results. We aimed to compare external jugular venous (EJV) access with internal jugular venous (IJV) access for effectiveness, ease of procedure, complications, and treatment cost in pediatric shock. Subjects and Methods: This was a prospective, nonrandomized, observational study from January 2014 to June 2015 in 66 pediatric patients with shock at a 7-bedded pediatric intensive care unit. Parents were explained about both routes. Depending on their affordability and consent, one route was chosen. Pertinent data were obtained, and analysis was done as per objectives. Results: EJV and IJV had 50 and 16 patients, respectively. Baseline characteristics were comparable. Death and discharge against medical advice rates are high in both the groups. No procedure-related life-threatening complications in any group and local site problems were similar in both the groups. Overall attempts and duration of procedure were similar in both the groups, and although the initial cost of the procedure of the IJV group was higher, overall final hospital bill had no significant difference. The median (Q1, Q3) hours of achieving shock-free status were 48 (24, 96) and 46 (12, 108) (P = 0.412). The median (Q1, Q3) improvement in base deficit at the end of 24 h was −4.5 (−8.1, 0.27) and −1.9 (−4.2, −0.6) (P = 0.259) in the EJV and IJV groups, respectively. Conclusion: For pediatric shock management, EJV access is an effective, easy, and cost economic procedure without significant complications as compared to IJV access.

Pathogenesis and Management in Cerebrovenous Outflow Disorders.

In keeping with its status as one of the major causes of disability and mortality worldwide, brain damage induced by cerebral arterial disease has been the subject of several decades of scientific investigation, which has resulted in a vastly improved understanding of its pathogenesis. Brain injury mediated by venous etiologies, however, such as cerebral, jugular, and vertebral venous outflow disturbance, have been largely ignored by clinicians. Unfortunately, this inattention is not proportional to the severity of cerebral venous diseases, as the impact they exact on the quality of life of affected patients may be no less than that of arterial diseases. This is evident in disease sequelae such as cerebral venous thrombosis (CVT)-mediated visual impairment, epilepsy, and intracranial hypertension; and the long-term unbearable head noise, tinnitus, headache, dizziness, sleeping disorder, and even severe intracranial hypertension induced by non-thrombotic cerebral venous sinus (CVS) stenosis and/or internal jugular venous (IJV) stenosis. In addition, the vertebral venous system (VVS), a large volume, valveless vascular network that stretches from the brain to the pelvis, provides a conduit for diffuse transmission of tumors, infections, or emboli, with potentially devastating clinical consequences. Moreover, the lack of specific features and focal neurologic signs seen with arterial etiologies render cerebral venous disease prone to both to misdiagnoses and missed diagnoses. It is therefore imperative that awareness be raised, and that as comprehensive an understanding as possible of these issues be cultivated. In this review, we attempt to facilitate these goals by systematically summarizing recent advances in the diagnosis and treatment of these entities, including CVT, CVS stenosis, and IJV stenosis, with the aim of providing a valid, practical reference for clinicians.

Venous Waveform Analysis Correlates With Echocardiography in Detecting Hypovolemia in a Rat Hemorrhage Model.

Assessing intravascular hypovolemia due to hemorrhage remains a clinical challenge. Central venous pressure (CVP) remains a commonly used monitor in surgical and intensive care settings for evaluating blood loss, despite well-described pitfalls of static pressure measurements. The authors investigated an alternative to CVP, intravenous waveform analysis (IVA) as a method for detecting blood loss and examined its correlation with echocardiography. Seven anesthetized, spontaneously breathing male Sprague Dawley rats with right internal jugular central venous and femoral arterial catheters underwent hemorrhage. Mean arterial pressure (MAP), heart rate, CVP, and IVA were assessed and recorded. Hemorrhage was performed until each rat had 25% estimated blood volume removed. IVA was obtained using fast Fourier transform and the amplitude of the fundamental frequency (f1) was measured. Transthoracic echocardiography was performed utilizing a parasternal short axis image of the left ventricle during hemorrhage. MAP, CVP, and IVA were compared with blood removed and correlated with left ventricular end diastolic area (LVEDA). All 7 rats underwent successful hemorrhage. MAP and f1 peak amplitude obtained by IVA showed significant changes with hemorrhage. MAP and f1 peak amplitude also significantly correlated with LVEDA during hemorrhage (R = 0.82 and 0.77, respectively). CVP did not significantly change with hemorrhage, and there was no significant correlation between CVP and LVEDA. In this study, f1 peak amplitude obtained by IVA was superior to CVP for detecting acute, massive hemorrhage. In addition, f1 peak amplitude correlated well with LVEDA on echocardiography. Translated clinically, IVA might provide a viable alternative to CVP for detecting hemorrhage.

Comparative analysis of mechanical complications of emergency versus planned ultrasound-guided internal jugular venous (IJV) cannulation: data from the emergency room of a third-level hospital in Quito, Ecuador

Background: Central venous catheters (CVC’s) are useful tools for the treatment of critically ill patients, especially in the emergency room, and are recognized for decreasing rates of failure and mechanical complications. Certain parameters can act as predictors to determine the likelihood of this type of complication. The aim of this study is to determine the incidence and predictors of mechanical complications using internal jugular venous (IJV) cannulation, especially when considering planned versus emergency cannulation. Methods: A prospective, observational study was performed at Hospital de los Valles, Quito, Ecuador, during a three-year period. All patients who presented to the emergency room with an indication for IJV cannulation and with no potential contraindications were included. Demographic, safety and procedure related data were collected. Variables were analyzed using STATA, and p-values &lt;0.05 were considered significant. Results: A total of 142 patients were included. The majority of procedures (64%) were planned. The main indication for CVC placement via IJV cannulation was chronic renal failure (54%), all of which were planned procedures, followed by sepsis (15%), where most procedures (91%) were emergencies. The IJV was anatomically located lateral to the carotid artery in 38.73% of cases. Mechanical/technical complications were reported in 13 patients. Cannulation time greater than two minutes was found to be the only factor independently associated with a higher probability (12.4 times) of developing mechanical/technical complications. The vessel location did not affect the incidence of complications either in emergency or planned procedures when using ultrasound. Conclusions: Ultrasound-guided IJV cannulation is a safe technique that can be performed as an emergency or planned procedure without increased complication rates in the emergency room. Additionally, a puncture time of less than two minutes is associated with the safest profile in this patient population.

Is Hyperoxic Hyperventilation Caused by Reduced Carbon Dioxide Washout or Disturbed Brain Redox Homeostasis?

Under oxygen‐enriched conditions, humans present a biphasic ventilatory response that is initially characterized by reduced ventilation (V̇E) as hyperoxia (HX) inhibits the peripheral chemoreceptors. This short‐lived response precedes a paradoxical increase in V̇E that has been termed hyperoxic hyperventilation. Proposed but untested mechanisms for this paradoxical response include central chemoreceptor stimulation via either an increased cerebral partial pressure of carbon dioxide (CO2), which would result from reductions in cerebral blood flow (CBF) and brain CO2–[H+] washout, or (2) an HX‐induced exaggerated production of reactive oxygen species (ROS). To determine the mechanism behind the paradoxical increase in V̇E during hyperoxemia, we submitted 8 healthy young men (24±1 yrs) to 10‐min trials of poikilocapnic HX under (1) saline or (2) ascorbic acid (AA) infusion. V̇E, arterial (a) and internal right jugular venous (Jv) PO2, PCO2, pH, oxidant (8‐isoprostane), and antioxidant (AA) markers, as well as volumetric CBF (Doppler ultrasound) responses, were quantified at the last minute of each trial. Under saline infusion, HX evoked an increase in PaO2 followed by a hyperventilatory response (+3.0 ± 1.2 L/min, p = 0.003) and arterial hypocapnia (−2.4 ± 0.9 mmHg, p = 0.03). HX also evoked a small but significant reduction in CBF (−219.6 ± 36.8 mL/min, p = 0.001) that was followed by unchanged PjvCO2 (−0.1 ± 0.7 mmHg, p = 0.619) and pH (0.001 ± 0.005, p = 0.957). HX under saline infusion also provoked an increase in arterial 8‐isoprostane (18.6 ± 7.5 pg/mL, p = 0.04). On the other hand, intravenous AA augmented arterial antioxidant markers (+584.1 ± 64.6, p = 0.0001 vs. saline) and blunted not only the increase in arterial 8‐isoprostane (−10.7 ± 9.5 pg/mL, p = 0.204) but also the HX‐induced hyperventilation (+0.87 ± 0.64 L/min, p = 0.232) and the arterial hypocapnia (−1.7 ± 0.5 mmHg, p = 0.04 vs. saline) observed during infusion of saline. HX under AA infusion also blunted CBF hypoperfusion (−41.8 ± 26.3 mL/min, p = 0.001 vs. saline) that, in turn, was followed by increases in PjvO2 (+5.3 ± 0.7 mmHg, p = 0.006 vs. saline), PjvCO2 (+1.1 ± 0.50 mmHg, p = 0.03 vs. saline) and a reduction in pH (−0.012 ± 0.004, p = 0.01) that may be explained by the Haldane effect. These findings suggest that hyperoxic hyperventilation is not a consequence of an increased cerebral CO2 partial pressure and a reduced brain CO2–[H+] washout but mediated by central chemoreceptor stimulation likely evoked by excessive production of ROS.Support or Funding InformationSupport: FaperRJ, CNPq, CAPES

Determination and prediction of the appropriate depth of right internal jugular vein catheterization via the middle approach in adults using transesophageal echocardiography.

The appropriate depth of right internal jugular venous (RIJV) catheterization is still under debated. In this study, transesophageal echocardiography (TEE) is used to develop a prediction formula for fixed RIJV catheter depth. Eighty patients with indications for intraoperative TEE and central line placement were enrolled. After intubation, a RIJV catheter was inserted via the middle approach using the Seldinger technique. When the J-tip of the guide wire appeared at the junction of the superior vena cava and the right atrium under TEE guidance, the guide wire was pulled back by approximately 2-3cm, until its tip was out of the pericardial fold. This depth was regarded as the insertion depth of the central venous catheter. Body landmark distance was measured, and the prediction formula was generated. The mean central line depth after TEE-guided placement was 15.1±1.7cm. The prediction formula developed is as follows: Insertion depth=(Height ÷ 20)+(D÷2), where D equals the distance from the insertion point to the sternal angle via the right sternoclavicular joint (r=0.595, r2 =0.354, P<0.01). TEE is an effective method for determining the appropriate insertion depth for an RIJV catheter. The prediction formula can be used as a reference for future RIJV catheterizations via the middle approach.

Leadless pacing: Going for the jugular.

BackgroundLeadless pacing is generally performed from a femoral approach. However, the femoral route is not always available. Until now, data regarding implantation using a jugular approach other than a single‐case report were lacking.MethodsThe case records of all patients who underwent internal jugular venous (IJV) leadless pacemaker implantation (Micra, Medtronic, Dublin, Ireland) at our center were analyzed retrospectively.ResultsNineteen patients underwent IJV leadless pacemaker implantation, nine females, mean age of 77.5 ±9.6 years; permanent atrial fibrillation in all patients with normal left ventricular ejection fraction. Implant indication was atrioventricular conduction disturbance in 10, pre‐AV node ablation in seven, and replacement of a conventional VVI pacemaker in two (infection in one and lead malfunction in the other). The device was positioned at the superior septum in seven patients, apicoseptal in seven patients, and midseptal in five patients. In 12 patients, a sufficient device position was obtained at the first attempt, in three at the second, in one at the third, in one at the fourth, and in two at the sixth attempt.The mean pacing threshold was 0.56 ± 0.39V at 0.24‐ms pulse width, sensed amplitude was 9.1 ± 3.2 mV, mean fluoroscopy duration was 3.1 ± 1.6 min. There were no vascular or other complications. At follow‐up, electrical parameters remained stable in 18 of 19 patients.ConclusionAlthough experience is minimal, we suggest that the IJV approach is safe and may be considered in patients where the femoral approach is contraindicated.

Subarachnoid hemorrhage after transient global amnesia caused by cerebral venous congestion: case report

BackgroundTransient global amnesia is reported to be caused by cerebral venous congestion. Internal jugular venous flow reversal in particular with the Valsalva maneuver leads to cerebral venous congestion. In addition, Valsalva maneuver can also induce subarachnoid hemorrhage. Transient global amnesia and subarachnoid hemorrhage might have common a pathophysiology in cerebral venous congestion.Case presentationWe report here the case of a 57-year-old woman who twice experienced convexal subarachnoid hemorrhage just after straining at stool following an episode of transient global amnesia. Digital subtraction angiography showed left temporal congestion. Left jugular vein ultrasonography revealed reflux with the Valsalva maneuver only in acute phase, indicating transient cerebral venous congestion.ConclusionsSubarachnoid hemorrhage followed by transient global amnesia indicates a common factor between them. Transient venous congestion is discussed in order to explain this rare phenomenon.

Placement of tunnelled hemodialysis catheters across stenotic and occluded central veins.

PURPOSE. The purpose of this study was to evaluate the efficacy of placement of tunneled hemodialysis catheters in patients with occluded or stenotic central veins. MATERIALS AND METHODS. Data were prospectively collected for 26 patients (11 male, 15 female, mean age 52 years) referred for placement of tunneled hemodialysis catheters with central venous stenoses or occlusions. The central venous occlusions or stenoses were recanalized using traditional interventional catheter and guidewire techniques.<br />RESULTS. Thirty central venous access procedures were performed of which 28 (93%) procedures resulted in successful tunneled catheter insertion. Twenty-one internal jugular venous (13 right, 8 left) and 7 subclavian venous (3 right, 4 left) catheters were placed. Eighteen stenotic and 10 occluded venous segments were crossed including the brachiocephalic vein (n = 22), subclavian vein (n = 2), and the superior vena cava (4). One patient required insertion of a metallic stent to facilitate passage of the hemodialysis catheter across an occluded brachiocephalic vein. No procedure-related complications occurred. No episodes of upper extremity swelling or superior vena cava syndrome occurred following catheter insertion.<br />CONCLUSIONS. Insertion of tunneled hemodialysis catheter across occluded or stenotic central veins is technically feasible and safe. The use of occluded or stenotic central veins for catheter access preserves patent central veins for future shunt access.

Competitive apnea and its effect on the human brain: focus on the redox regulation of blood-brain barrier permeability and neuronal-parenchymal integrity.

Static apnea provides a unique model that combines transient hypertension, hypercapnia, and severe hypoxemia. With apnea durations exceeding 5 min, the purpose of the present study was to determine how that affects cerebral free-radical formation and the corresponding implications for brain structure and function. Measurements were obtained before and following a maximal apnea in 14 divers with transcerebral exchange kinetics, measured as the product of global cerebral blood flow (duplex ultrasound) and radial arterial to internal jugular venous concentration differences ( a-vD). Apnea increased the systemic (arterial) and, to a greater extent, the regional (jugular venous) concentration of the ascorbate free radical, resulting in a shift from net cerebral uptake to output ( P < 0.05). Peroxidation (lipid hydroperoxides, LDL oxidation), NO bioactivity, and S100β were correspondingly enhanced ( P < 0.05), the latter interpreted as minor and not a pathologic disruption of the blood-brain barrier. However, those changes were insufficient to cause neuronal-parenchymal damage confirmed by the lack of change in the a-vD of neuron-specific enolase and human myelin basic protein ( P > 0.05). Collectively, these observations suggest that increased cerebral oxidative stress following prolonged apnea in trained divers may reflect a functional physiologic response, rather than a purely maladaptive phenomenon.-Bain, A. R., Ainslie, P. N., Hoiland, R. L., Barak, O. F., Drvis, I., Stembridge, M., MacLeod, D. M., McEneny, J., Stacey, B. S., Tuaillon, E., Marchi, N., De Maudave, A. F., Dujic, Z., MacLeod, D. B., Bailey, D. M. Competitive apnea and its effect on the human brain: focus on the redox regulation of blood-brain barrier permeability and neuronal-parenchymal integrity.