Cannula Research Articles

Intravenous Ketamine to Facilitate Transport of Agitated Patients to the ECT Clinic.

Electroconvulsive therapy (ECT) can be effective for a variety of psychiatric conditions, including for some patients who are very psychotic or agitated. Transferring such patients from the psychiatric ward to the ECT clinic can pose significant challenges for treating teams, as they try to minimize the use of restraint. We developed a protocol for safe transfer of such patients using sedation with ketamine. An intravenous cannula is inserted on the ward in a low stimulus environment with gentle supportive holds. Intravenous ketamine is given in a bolus at 0.5-2.0 mg/kg. The patient is transported on a transfer bed to the ECT clinic within a few minutes, and usual ECT process is immediately followed. We describe 6 patients who were given between 1 and 11 ECT treatments using this method. All of them finished ECT courses without the need for ketamine sedation. Five of them regained capacity, provided informed consent for further ECTs, and eventually reached remission. Ketamine can be used to manage risk and transfer agitated patients to an ECT clinic for treatment.

A prospective randomized comparative study to evaluate the safety and efficacy of topical quick penetrating solution (QPS) of Heparin (1000 IU/ml) versus Heparin gel (200 IU/ml) in prevention of intravenous cannula related thrombophlebitis in post operative onco surgical intensive care unit (ICU) patients

A prospective randomized comparative study to evaluate the safety and efficacy of topical quick penetrating solution (QPS) of Heparin (1000 IU/ml) versus Heparin gel (200 IU/ml) in prevention of intravenous cannula related thrombophlebitis in post operative onco surgical intensive care unit (ICU) patients

Hemodynamic Effects and Clinical Outcomes of Left Atrial Veno-Arterial Extracorporeal Membrane Oxygenation (LAVA-ECMO) in Cardiogenic Shock

Left atrial veno-arterial extracorporeal membrane oxygenation (LAVA-ECMO) in cardiogenic shock (CS) is a novel mechanical cardiocirculatory support strategy that provides robust cardiocirculatory support and simultaneous left and right atrial venting by way of a multifenestrated transeptal catheter. We performed a single-center retrospective analysis of all patients aged ≥18 years with CS who underwent LAVA-ECMO at a quaternary care institution from 2018 to 2023. Clinical outcomes and prehemodynamics and posthemodynamics were evaluated. A total of 68 patients were analyzed (75% were men, 72% were white, median age of 63 years). The indications for LAVA-ECMO were CS because of myocardial infarction (29.4%), biventricular failure (26.5%), and/or valvular heart disease (26.5%). Trans-septal puncture was guided by intracardiac echocardiography (86.8%) or transesophageal echocardiography (13.2%). Arterial cannulation was performed by way of transcaval access in 25% of the cases. Post-LAVA-ECMO cannulation was associated with substantial improvement in the hemodynamics within 24 hours after cannulation, including reduction in right atrial pressure (absolute mean difference: -5.0 mm Hg, p <0.001), mean pulmonary artery pressure (-9.0 mm Hg, p <0.001), pulmonary capillary wedge pressure (-10.0 mm Hg, p <0.001), and left ventricular end-diastolic pressure (-14.0 mm Hg, p <0.001). Survival to decannulation occurred in 69.1%, whereas the 30-day survival from cannulation was 51.5%. The in-hospital all-cause mortality was 51.5%. Only 5 patients (7.4%) required additional mechanical circulatory support (MCS) (4 Impella, 1 veno-arterio-venous extracorporeal membrane oxygenation). There were no complications related to transeptal placement of the venous ECMO cannula. In conclusion, LAVA-ECMO, an MCS strategy providing biatrial drainage, appears to also provide simultaneous left ventricular venting, as demonstrated by improved invasive hemodynamics. Although the procedure appears safe, with no direct complications to interatrial septal cannulation, postcannulation complications remain high, and further studies are needed to evaluate the full safety profile of LAVA-ECMO compared with alternative MCS strategies.

Abstract 4120140: Catastrophic Bioprosthetic Aortic Valve Thrombosis: An Unappreciated Complication of Veno-Arterial Extracorporeal Membrane Oxygenation Support in Cardiogenic Shock

Description of Case: A 56-year-old male with a history of cardiac sarcoidosis with biventricular systolic heart failure (HF) and a bioprosthetic aortic valve presented with acute decompensated HF. Progressive cardiogenic shock and hemodynamic instability ensued, requiring urgent bedside placement of an intra-aortic balloon pump (IABP) which provided only marginal hemodynamic support. After extensive multidisciplinary discussion, emergent cannulation for veno-arterial ECMO (VA-ECMO) was performed at the bedside as a bridge-to-decision for advanced HF therapies. The IABP was left in place for LV venting. Within 72 hours, extensive bilateral pulmonary opacities had developed. It was later realized that true LV ejection (as evidenced by aortic pulsatility on the arterial line) was not present and had been masked by pseudo-pulsatility provided by IABP inflations and deflations. Compared to an echocardiogram done 7 days prior to VA-ECMO cannulation, the bioprosthetic leaflets were no longer opening, thrombosis of the AV had occurred, and thrombus formation along the ECMO venous drainage cannula was noted. Failure to achieve LV venting culminated in complete thrombosis of the entire LV and LA and the patient ultimately expired. Discussion: Bioprosthetic valve thrombosis is a lesser-known complication of VA-ECMO support, with most reports involving bioprosthetic valves in the mitral position. Indeed, bioprosthetic valve thrombosis occurs at a higher rate than native valve thrombosis during VA-ECMO support. However, bioprosthetic AV thrombosis is an extremely rare complication of VA-ECMO support and arguably results in a more catastrophic scenario as most traditional approaches to LV unloading are contraindicated. The optimal LV unloading strategy for these patients (IABP, Impella, surgical apical unloading, etc) is unknown. Data from large retrospective analyses have demonstrated extremely poor outcomes when prosthetic valve thrombosis occurs, and it is thus critical to prevent this complication from developing. In contrast to IABP counter-pulsation, the benefit of upfront transvalvular LV venting with an Impella device safeguards the presence of a direct LV vent in the event of bioprosthetic AV thrombosis and eliminates the false reassurance of IABP pseudo-pulsatility. Further studies are needed to better elucidate the optimal LV unloading strategy in patients with bioprosthetic valves, particularly in the aortic position.

The Stress-Induced Hyperprolactinemia Might Not Be that Stress-Induced as Argued: Observational Case-Control Study

ObjectiveThe mechanism behind prolactin (PRL) elevation in stress-induced hyperprolactinemia (si-HP) in humans is unclear. This study aimed to investigate the effect of psychological stress and venous puncture (VP) pain on si-HP. MethodsThe study included 91 individuals (9 males, 82 females) referred for HP. Anxiety levels were assessed using the Anxiety Sensitivity Index-3 (ASI-3) and the State-Trait Anxiety Inventory (STAI-1 and STAI-2), and visual scales were used to evaluate trypanophobia, nosocomephobia, and scanxiety. Serial PRL measurements were performed with venous cannula (VC) at 0 minute (min), 30 min, and 60 min for the first 32 patients and with the VP method at the same intervals for the following 59 patients. si-HP was defined as PRL levels at 60 min (PRL 60min) decreasing to normal limits according to gender. ResultsThere were 23 HP (−), 25 HP (+), and 19 si-HP individuals, as well as 24 with macroprolactinaemia. The frequency of si-HP in the VC group (n = 7/32) was similar to that in the VP group (12/59, P = .9). The prolactin levels at 0 minute (PRL0min) and prolactin levels at 60 minutes (PRL60min) levels of the VC group were similar to those of the VP group. Trypanophobia, nosocomephobia, scanxiety, ASI-3, STAI-1, and STAI-2 scale scores were similar between the si-HP group and other groups. Trypanophobia, nosocomephobia, scanxiety, ASI-3, STAI-1, and STAI-2 scales scores were not correlated with PRL0min or PRL60min levels. ConclusionSi-HP is independent of states momentary or trait anxiety, and phobias trypanophobia, nosocomephobia and scanxiety. In this context, the relevance of the nomenclature of si-HP is controversial.

Evaluation of extra-corporeal membrane oxygenator cannulae in pulsatile and non-pulsatile pediatric mock circuits.

This study evaluated the hemodynamic performance of arterial and venous cannulae in a compliant pediatric extracorporeal membrane oxygenation (ECMO) mock circuit in pulsatile and non-pulsatile flow conditions. The ECMO setup consisted of an oxygenator, diagonal pump, and standardized-length arterial/venous tubing with pressure transducers. A validated left-heart mock loop was adapted to simulate pediatric conditions. The pulsatile flow was driven by a computer-controlled piston pump set at 120 bpm. A roller pump was used for non-pulsatile conditions. The circuit was primed with 40% glycerol-based solution. The cardiac output was set to 1 L/min and the aortic pressure to 40-50 mmHg. Four arterial cannulae (8Fr, 10Fr, 12Fr, 14Fr) and five venous cannulae (12Fr, 14Fr, 16Fr, 18Fr, 20Fr) (Medtronic, Inc., Minneapolis, MN, USA) were tested at increasing flow rate in 12 combinations. The pulsatile condition required lower ECMO pump speeds for all cannulae combinations at a given flow rate, inducing a significantly smaller increase of flow in the mock loop. Under non-pulsatile conditions, the aortic and arterial pressures in the cannulae were higher (p < 0.01) while no significant differences in pressure drop and pressure-flow characteristics (M-number) were observed. The total hemodynamic energy was higher in case of non-pulsatile flow (p < 0.01). Under non-pulsatile conditions, the system was characterized by overall higher pressures, resulting in higher support to the patient. The consequent increase of potential energy compensates for increases of kinetic energy, leading to a higher total hemodynamic energy. Pressure gradients and M number are independent of the testing conditions. Pulsatile testing conditions led to more physiological testing conditions, and it is recommended for ECMO testing.

Incidence of peripheral intravenous cannula induced phlebitis and its determinants among admitted patients in Ethiopia: systematic review and meta analysis, 2024

BackgroundPeripheral venous catheters (PVCs) are frequently used in clinical practice. Nonetheless, individuals who receive intravenous injections frequently have varying degrees of phlebitis. According to pertinent research, the catheter gauge, insertion site, and length of catheterization are strongly correlated with the incidence of phlebitis. However, no meta-analysis on the combined incidence of phlebitis and its contributing factors has been conducted. Thus, the purpose of this meta-analysis was to close the previously identified gaps.MethodA literature survey was conducted using electronic databases (CINAHL, Embassy, Google Scholar, and PubMed), and 4 studies were included they used peripheral intravenous catheters for therapeutic or volumetric infusion and reported phlebitis incidence rates. Random effects meta-analyses were performed to obtain the overall and subgroup phlebitis incidence rates and odds ratio for phlebitis incidence.ResultsThe incidence of phlebitis was 41 per 100 catheters (95% CI 0.22–0.60). There were 1584 patients in the included studies to know the incidence of phlebitis. In the subgroup analysis, the incidence of phlebitis in neonatal and infant patients was 30% (95% CI 0.25–0.34), in pediatrics patients was 34% (95% CI 0.29–0.38), and in adult patients was 50% (95% CI 0.11–0.89) respectively. Joint involvement in the PIVC (AOR: 2.44, 95% CI 1.67, 3.2), longer catheter dwell time (AOR = 3.96, 95% CI 1.59–7.33), and drug and blood administration in one vein (AOR = 1.91, 95% CI 1.67–2.15) were the most common factors associated with the incidence of phlebitis in Ethiopia.ConclusionThis meta-analysis indicates that PIVC-induced phlebitis is highly prevalent in Ethiopia. This meta-analysis identified significant risk factors for the development of phlebitis including medications and blood administered in a single vein, longer cannula dwelling times, and joint involvement in peripheral intravenous cannula insertion. Using the right interventions can lower the chance of developing phlebitis.

Prevalence of Needle Stick Injuries Among Healthcare Workers at a Tertiary Care Centre in Kochi, India.

Background Needle stick injuries (NSIs) are a prevalent occupational hazard among healthcare workers (HCWs) globally. Strict adherence to standard work precautions by all HCWs at all times and the implementation of post-exposure prophylaxis (PEP) are measures for reducing the occurrence of NSIs. However, NSIs are poorly documented in the literature and may be a cause of morbidity in the long run. Objectives Our study aims to determine the prevalence of NSIs among HCWs and its associated factors in a tertiary healthcare centre in Kerala, India. Methods A cross-sectional study was conducted among 210 consenting HCWs who worked in different blocks of a tertiary care hospital in the Ernakulam district, Kerala, India. Data was collected using a semi-structured questionnaire through personal interviews.The questionnaire gathered sociodemographic information, details regarding NSI occurrences over the past one year, the devices involved and PEP. Data analysis was performed using StatisticalPackage for the Social Sciences (IBM SPSS Statistics for Windows, IBMCorp., Version 20.0, Armonk,NY), and categorical variables were expressed as frequencies and percentages. The chi-square test and binomial logistic regression were employed to identify factors associated with NSIs. Results The prevalence of NSIs among HCWs in the past 12 months was 31% (65 out of 210), with an average of 1.34 NSIs per HCW per year. The most commonly involved device was the intravenous (IV) cannula, and 22 out of 65 (33.8%)injuries occurred during injection procedures. A majority (45 out of 65; 69.23%) of HCWs reported NSI and 51 of them (78.4%) received PEP. Logistic regression analysis showed that HCWs aged over 31 years (adjusted odds ratio (AOR): 3.39; 95% confidence interval (CI): 1.29-8.42) were independently associated with a higher occurrence of NSIs. Conclusion Our findings underscore the importance of implementing comprehensive safety measures, including strict adherence to standard work precautions and timely administration of PEP.

A human cadaveric model for venous air embolism detection tool development.

A human cadaveric model combining standard lung protective mechanical ventilation and modified cardiac bypass techniques was developed to allow investigation into automated modes of detection of venous air emboli (VAE) prior to in vivo human or animal investigations. In this study, in order to create an artificial cardiopulmonary circuit in a cadaver that could mimic VAE physiology, the direction of flow was reversed from conventional cardiac bypass. Normal saline was circulated in isolation through the heart and lungs as opposed to the peripheral organs by placing the venous cannula into the aorta and the arterial cannula into the inferior vena cava with selective ligation of other vessels. Mechanical ventilation and this reversed cardiac bypass scheme allowed preliminary detection of VAE independently but not in concert in our current simulation scheme due to pulmonary edema in the cadaver. A limited dissection approach was used initially followed by a radical exposure of the great vessels, and both proved feasible in terms of air signal detection. We used electrical impendence as a preliminary tool to validate detection in this cadaveric model however we theorize that it would work for echocardiographic, intravenous ultrasound or other novel modalities as well. A cadaveric model allows monitoring technology development with reduced use of animal and conventional human testing.

Differential hypoxemia during peripheral cardiopulmonary bypass.

Minimally invasive cardiac surgery (MICS) for mitral valve repair often uses cardiopulmonary bypass (CPB) through peripheral femoro-femoral cannulation. A rare complication of differential hypoxemia can cause upper body hypoxia. A 38-year-old man with Barlow Syndrome underwent MICS mitral valve repair with peripheral CPB. During the procedure, his right upper limb SpO2 dropped to 65% due to dislodgement of the venous cannula from the superior vena cava (SVC), causing inadequate right heart venous drainage, leading to differential hypoxemia. Repositioning the venous cannula to the SVC restored SpO2 to 100%, allowing the surgery to proceed without complications. Differential hypoxemia happens when deoxygenated blood from the left ventricle mixes with oxygenated CPB blood. A literature review found only one previous case of this complication on peripheral CPB for MICS. Unlike our case, Kanda et al. monitored cerebral hypoxia, underscoring the importance of cerebral oxygenation monitoring in future MICS procedures due to higher stroke risk compared to conventional sternotomy. We recommend cerebral oxygenation monitoring in future MICS to prevent neurological complications, and highlight the need for effective team communication in the cardiac operating theatre.

Mediastinal Shift Index: A Novel Postnatal Measurement of Mediastinal Movement that Predicts Survival in Neonates With Congenital Diaphragmatic Hernia on Extracorporeal Membrane Oxygenation

PurposeMediastinal position varies in neonates with congenital diaphragmatic hernia (CDH), reflecting contralateral shift due to mass effect. We aimed to create and validate a postnatal measurement of mediastinal positioning using chest radiographs in neonates with CDH who require extracorporeal membrane oxygenation. MethodsChart review identified neonates with CDH who required veno-arterial extracorporeal membrane oxygenation between 2017 and 2022. Mediastinal shift index (MSI) is the ratio of the distance between the venous cannula tip and the contralateral chest wall divided by the total width of the contralateral hemithorax. Three raters completed MSI measurements at designated timepoints: after cannulation, post- CDH repair, and immediately before decannulation. Intraclass correlation coefficients (ICC) assessed inter-rater agreement. Initial MSI and observed/expected lung head ratio (O/E LHR) were correlated and compared between survivors and non-survivors. Receiver operative characteristic (ROC) curve analysis evaluated the ability of MSI and O/E LHR to predict survival. Results38 neonates were included. MSI demonstrated excellent agreement (ICC>0.98) amongst raters. Initial MSI and O/E LHR had a moderate positive correlation (Spearman correlation = 0.47, p = 0.014). Initial MSI differed significantly between survivors and non-survivors (0.52 vs. 0.33, p = 0.035) as did O/E LHR (0.36 vs. 0.26, p = 0.036). ROC analysis revealed initial MSI >0.35 was predictive of survival with 73% sensitivity and 70% specificity. ConclusionMediastinal shift index is reliable and predicted survival with a higher specificity than O/E LHR. Future studies will elucidate the role of trending MSI over a patient's course to inform interventions to optimize mediastinal position. Level of Evidence3.

Vascular Complications in Extracorporeal Membrane Oxygenation-A Narrative Review.

The establishment of a peripheral ECMO circuit can lead to significant arterial and venous complications in 10-30% of patients. Vascular complications, particularly acute limb ischemia, are associated with worsening overall outcomes. Limb ischemia occurs significantly more frequently in the early stages of VA ECMO than in VV ECMO. Mechanisms of limb ischemia include arterial obstruction, cannulation injury, loss of pulsatile flow, thromboembolism, venous stasis from compressive obstruction with large venous cannulas, and systemic vasoconstriction due to shock and pharmacologic vasoconstriction. The care team may use several mitigation strategies to prevent limb ischemia. Arterial and venous complications can be mitigated by careful access site selection, minimizing cannula size, placement of distal perfusion and/or outflow catheter(s), and continuous NIRS monitoring. Rapid intervention, when ischemia or compartment syndrome occurs, can reduce limb loss but may not affect the mortality and morbidity of the ECMO patient in the long term due to their underlying conditions and the etiology of the ECMO need.

Using Simulation Models to Train Clinicians in the Use of Point-of-Care Ultrasound.

The use of point-of-care ultrasound (POCUS) has shown to be a beneficial non-invasive vascular access assessment method by clinicians, which can provide critical elements of visual and measurable information that proves to be useful in the context of vascular access cannulation, in combination with the practical skill of the clinician performing the cannulation. However, the use of POCUS in this context is to practically train and enable individuals who are novices in using this technique to become proficient in performing this task subsequently on patients in a careful and successful way. The simulation of these vascular conditions may be useful to help healthcare professionals learn, understand, apply, and establish such practical skills for vascular cannulation safely to achieve the desired outcomes. This project intended, through the attendance of a half-day workshop, to establish skills to use POCUS in connection with simulation models and perform specific tasks to enable clinicians to use this method in their clinical practice for vascular access cannulation in patients. A mixed-methods longitudinal study design was used to evaluate the effect of a point-of-care ultrasound workshop for peripheral intravenous cannula insertion, including specific tasks for the participants to be performed on simulation models. A total of 81 individuals participated in 11 half-day workshops through 2021 and 2022. Offering a workshop that uses simulation models in combination with various POCUS devices is useful in establishing this newly learned skill in clinicians, such as measurements of depth, caliper, and direction of a vein with POCUS prior to cannulation providing essential anatomical facts to the operator, which increases the likelihood of first-time success in cannulation.

Circadian rhythm of brain-derived neurotrophic factor in serum and plasma.

The neurotrophic growth factor brain-derived neurotrophic factor (BDNF) plays a crucial role in various neurodegenerative and psychiatric diseases, such as Alzheimer's disease, schizophrenia and depression. BDNF has been proposed as a potential biomarker for diagnosis, prognosis and monitoring therapy. Understanding the factors influencing BDNF levels and whether they follow a circadian rhythm is essential for interpreting fluctuations in BDNF measurements. We aimed to investigate the circadian rhythm of BDNF by collecting multiple peripheral venous blood samples from young, healthy male participants at 12 different time points over 24h. In addition, vital parameters, cortisol and insulin like growth factor 1 (IGF1) were measured to explore potential regulatory mechanisms, interfering variables and their correlations with BDNF concentration. The findings revealed that plasma BDNF did not exhibit any significant fluctuations over 24h, suggesting the absence of a circadian rhythm. However, serum BDNF levels decreased during sleep. Furthermore, serum BDNF showed a positive correlation with heart rate but a negative correlation with IGF1. No significant correlation was observed between cortisol and BDNF or IGF1. Although plasma BDNF suggests steady-state conditions, the decline of serum BDNF during the nocturnal period could be attributed to physical inactivity and associated with reduced haemodynamic blood flow (heart rate reduction during sleep). The type of sample collection (peripheral venous cannula vs. blood sampling using a butterfly system) does not significantly affect the measured BDNF levels. The sample collection during the day did not significantly affect BDNF analysis, emphasizing the importance of considering activity levels rather than timing when designing standardized protocols for BDNF assessments.

Incidence Of Peripheral Thrombophlebitis in Elective Versus Clinically Indicated Replacement of Intravenous Cannula. A Comparative Study

Introduction: Peripheral cannulations are one of the commonest procedures to be performed in hospital settings and peripheral thrombophlebitis is also a common complication that occurs after intravenous cannulations. The incidence rates are variable and there was a need to evaluate if it was different in our setting and also the reasons for its removal and other factors associated with this common but important problem. Methods: We randomized 288 patients who were admitted to the general surgical ward into elective and clinically indicated groups (n=144) in either group after taking informed consent. Cannula in the elective group were re-sited every 48 hours and only removed if there were signs suggestive of peripheral thrombophlebitis. Current and previous cannulation sites were examined by the investigator every 24 hours for any signs and symptoms of peripheral thrombophlebitis. Results: The incidence of peripheral thrombophlebitis was 15.3 % with 8.3 % (n=12) incidence in the elective and 22.2 % (n=32) in the clinically indicated group. The mean time of cannula removal was 56.86 hours. Conclusions: Elective re-siting of intravenous cannula every 48 hours results in a significant reduction in the incidence of peripheral thrombophlebitis when compared with clinically indicated re-siting.

The use of ultrasound is the simplest imaging technique to visualize a broken intravenous cannula

The use of ultrasound is the simplest imaging technique to visualize a broken intravenous cannula

Comparative Study of Mini-MONOKA Stenting and 24 G Intravenous Cannula Stenting in Cases of Canalicular Laceration: A Retrospective Study

Comparative Study of Mini-MONOKA Stenting and 24 G Intravenous Cannula Stenting in Cases of Canalicular Laceration: A Retrospective Study

Intracranial Pressure Monitoring Location: A Pilot Study on the Validation of Subdural Site with the Intraventricular Site.

Introduction Knowledge of preoperative and intraoperative intracranial pressure (ICP) enables the neuroanesthesiologist to optimize cerebral perfusion pressure. However, ICP is rarely monitored during the intraoperative period. In this report, subdural site ICP measurement is validated with intraventricular ICP measurement, and the feasibility of subdural ICP monitoring during the intraoperative period is discussed. Materials and Methods In this prospective pilot study, ICP measurement at the subdural site was achieved with an intravenous cannula and the ventricular site with a ventricular cannula. Both were transduced using a fluid-filled pressure transducer and connected to the monitor for display of the number and the waveforms. Monitoring of intraoperative ICP using both the techniques was done in all patients recruited into the study. The correlation between the two modalities of measurement was studied by the Spearman correlation test and their limits of agreement were studied using the Bland-Altman plot. A case series describing the perioperative management based on the subdural ICP values are also described. Results Subdural ICP showed a strong correlation with intraventricular ICP ( r s = 0.93, p = 0.01). Agreement analysis using the Bland-Altman plot showed that the mean difference of ICP between the modalities was 1.44 mm Hg (95% confidence interval, -0.6 to 3.49, p = 0.122). Discussion This study validates the ICP values measured at the subdural site with the intraventricular site. Subdural site ICP monitoring can be achieved rapidly with readily available systems and helps in making intraoperative clinical decisions. Conclusion Cannula-based subdural ICP is a satisfactory alternative to intraventricular ICP monitoring in the intraoperative period.

Bedside Technique for the Implantation of Licox Brain Tissue Oxygen Probes in Occipital Regions: A Technical Note

Continuous bedside monitoring of brain tissue oxygen levels is a crucial component in the management of comatose patients suffering from acute brain injury on neurointensive care units. Ensuring sufficient brain oxygenation is recognized as an essential objective within neurocritical care, aimed at safeguarding patients from secondary ischemia. Hypoperfusion in occipital and the posterior watershed regions often remains undetected, as the placement of probes in these areas is challenging. A major concern is that patients would have to lie on the traditionally used implanted bolts due to the occipital entry point of the probes. Therefore, we present a novel technique compatible with magnetic resonance imaging that enables bedside placement of brain tissue oxygen probes without the use of a bolt in these areas. We conducted bedside implantations of Licox brain tissue oxygenation probes through Frazier's point utilizing peripheral venous cannulas on burr holes eliminating the need for bolts. A novel approach was successfully established for the bedside implantation of a Licox brain tissue oxygenation probe for occipital regions. This technical note describes the feasibility of a novel, simple, and straightforward bedside technique for boltless implantation of Licox brain tissue oxygen probes leading to rigid fixation and compatibility with magnetic resonance imaging.

Required volume for color flow injection test to confirm the intravascular placement of a peripheral venous catheter

Background: Confirmation of adequate peripheral intravenous catheter placement is essential before using venous catheters. The color flow injection test has been reported as a method with high sensitivity and specificity for this purpose. The technique involves administrating saline through the peripheral venous route to observe changes in the color flow pattern around the same vein at a more central location. However, the required volume of saline remains uncertain. This study aims to determine the appropriate dosage for conducting the test in pediatric patients and explore any potential correlations between dosage and patient characteristics. Methods: A prospective study was conducted in children under 6 years of age with American Society of Anesthesiologists Physical Status 1–2 presenting for general anesthesia. After an intravenous cannula was placed in the forearm under general anesthesia, normal saline was injected at a speed of approximately 1 mL/s while the axillary artery and vein were observed with color flow Doppler imaging. The volume of normal saline required to induce a change in the color flow pattern around the vessels was measured. Measurements were performed twice and averaged for comparison with patient characteristics and other factors. Results: The study cohort included 30 patients aged from 0.3 to 5.5 (2.6 ± 1.6) years. The change in color flow Doppler imaging was noted in all the patients, and the average volume was 1.40 ± 0.36 mL (95% confidence interval (CI), 1.27–1.54; p &lt; 0.001), which was significantly correlated with age, with a correlation coefficient of 0.435 (95% CI, 0.09–0.69; p = 0.02). Conclusions: The required volume for the color flow injection test is small; therefore, the test is easy to perform and minimally invasive in pediatric patients.