Fiberoptic Catheter Research Articles

Application of Anal Manometry in the Planning for Anal Fistula Surgery

Anal fistula does not heal spontaneously without surgery, and anal function should be preserved after muscle dissection, which is a challenge even to the most experienced surgeon. In order to develop a planner for anal fistula surgery, anal manometry used in the measurement of pressures in the anal canal to investigate the anal function is reviewed. In this review paper, current techniques are described and compared with each other, and technical and clinical challenges are discussed. There are four types of catheters used to measure anal sphincter pressure: water-perfused, solid-state, air-coupled, and fiber optic catheter. Parameters acquired by anal manometry and their relationship with fecal incontinence after anal fistula surgery are discussed. Vectormanometry can provide the pressure profile along the anal canal in three dimensional space, pressure vectorgram, and cross-sectional radial asymmetry, which have more advantages than the conventional method. Understanding the technology and development of anal manometry is critical for the anal fistula surgical planning. A novel design is highly desired for 3D pressure profile measurement along the entire anal canal simultaneously without pulling the catheter.

Intracranial pressure is elevated at 24 h post‐stroke in mice

AbstractBackgroundIt has long been assumed that post‐stroke intracranial pressure (ICP) elevation occurs because of large infarct and edema volumes. However, we have repeatedly shown ICP elevation at 24 h post‐stroke in the presence of little to no edema in rats. Biological processes are often conserved across species and types of injury. Therefore, we aimed to determine if an ICP rise occurs at 24 h post‐stroke in the presence of small infarct and edema volumes in mice.MethodsMice were randomized by random number table to either photothrombotic stroke or sham surgery (n = 15). Epidural ICP was recorded using a fiber optic catheter at 1 h post‐stroke (baseline) and between 23 and 24 h post‐stroke.ResultsICP was significantly higher at 24 h compared to baseline in stroke animals (n = 6; 10.71 ± 6.45 mmHg vs. 3.74 ± 2.20 mmHg, respectively; p = 0.03). ICP at 24 h was also significantly higher in stroke mice compared to sham (n = 6; 3.45 ± 1.43 mmHg; p = 0.02). There was no change in ICP in sham mice (p = 0.9). Edema volumes in stroke animals were small (0.04 ± 0.04 mm3) and unlikely to have caused significant ICP elevation.ConclusionThis study provides evidence of an edema‐independent ICP elevation following small ischemic stroke in mice. The occurrence of this rise supports our findings in other species and suggests it is caused by a previously undescribed mechanism.

The use of nanomaterials in advancing photodynamic therapy (PDT) for deep-seated tumors and synergy with radiotherapy.

Photodynamic therapy (PDT) has been under development for at least 40years. Multiple studies have demonstrated significant anti-tumor efficacy with limited toxicity concerns. PDT was expected to become a major new therapeutic option in treating localized cancer. However, despite a shifting focus in oncology to aggressive local therapies, PDT has not to date gained widespread acceptance as a standard-of-care option. A major factor is the technical challenge of treating deep-seated and large tumors, due to the limited penetration and variability of the activating light in tissue. Poor tumor selectivity of PDT sensitizers has been problematic for many applications. Attempts to mitigate these limitations with the use of multiple interstitial fiberoptic catheters to deliver the light, new generations of photosensitizer with longer-wavelength activation, oxygen independence and better tumor specificity, as well as improved dosimetry and treatment planning are starting to show encouraging results. Nanomaterials used either as photosensitizers per se or to improve delivery of molecular photosensitizers is an emerging area of research. PDT can also benefit radiotherapy patients due to its complementary and potentially synergistic mechanisms-of-action, ability to treat radioresistant tumors and upregulation of anti-tumoral immune effects. Furthermore, recent advances may allow ionizing radiation energy, including high-energy X-rays, to replace external light sources, opening a novel therapeutic strategy (radioPDT), which is facilitated by novel nanomaterials. This may provide the best of both worlds by combining the precise targeting and treatment depth/volume capabilities of radiation therapy with the high therapeutic index and biological advantages of PDT, without increasing toxicities. Achieving this, however, will require novel agents, primarily developed with nanomaterials. This is under active investigation by many research groups using different approaches.

Variability of Intradiscal Pressure During Cervical Spine Posterior-Anterior Mobilization: A Cadaveric Investigation

ObjectivesThe purpose of this study was to investigate in cadaveric specimens the reliability of measuring cervical intradiscal pressure (CIDP) and if posterior-anterior (PA) mobilizations targeting the cervical spine were associated with CIDP changes. MethodsCervical PA mobilizations were performed on the spinous processes of 7 (3 men, 4 women) cadaveric specimens using a servo-controlled linear actuator to provide 25N and 45N forces. CIDP measurements were performed at C4-5, C5-6, C6-7, and C7-T1 intervertebral discs (IVDs) using a fiberoptic catheter system that recorded CIDP for each IVD cervical segment. To assess CIDP measurement reliability, the intraclass correlation coefficient (ICC [3,k]) was calculated. Repeated measures Friedman analysis of variance assessed effect of cervical mobilizations on CIDP for before, during, and immediately after mobilization at 25N and 45N forces for each cervical IVD segment. ResultsAll CIDP measurements demonstrated excellent reliability (ICC >0.98). During the 25N mobilizations, the median CIDP varied from -0.12 to 0.91 (interquartile range, 5.22-5.36), while for 45N mobilizations the median ranged from -0.94 to 1.21 (interquartile range, -7.74 to 43.49). These changes were not statistically significant (P > .40) during 25N and 45N PA mobilizations, with the exception of C5-6 CIDP at 25N and 45N (P = .05 and .018, respectively). ConclusionThere was high CIDP variability between cadavers during and after mobilization. Mobilizations of 1 cervical vertebra resulted in both CIDP increase or decrease at adjacent and remote cervical IVD segments that were not consistent. Cervical PA mobilizations produced variable CIDP changes at adjacent and remote cervical segments in cadavers.

Automatic correction of the initial rotation angle error improves 3D reconstruction in endoscopic airway optical coherence tomography.

Endoscopic airway optical coherence tomography (OCT) is an advanced imaging modality capable of capturing the internal anatomy and geometry of the airway. Due to fiber-optic catheter bending and friction, the rotation speed of the endoscopic probe is usually non-uniform: at each B-scan image, the initial rotation angle of the probe is easily misaligned with that of the previous slices. During the pullback operation, this initial rotation angle error (IRAE) will be accumulated and will result in distortion and deformation of the reconstructed 3D airway structure. Previous attempts to correct this error were mainly manual corrections, which are time-consuming and suffered from observer variation. In this paper, we present a method to correct the IRAE for anatomically improved visualization of the airway. Our method derived the rotation angular difference of adjacent B-scans by measuring their contour similarity and then tracks the IRAE by formulating its continuous drift as a graph-based problem. The algorithm was tested on a simulated airway contour dataset, and also on experimental datasets acquired by two different long range endoscopic airway OCT platforms. Effective and smooth compensation of the frame-by-frame initial angle difference was achieved. Our method has real-time capability and thus has the potential to improve clinical imaging efficiency.

Intradiscal Pressure Responses to Cervical Spine Posterior-Anterior Mobilization to Promote Disc Nutrition

Research Objectives To investigate in cadaveric specimens if cervical PA mobilizations produce changes in CIDP. Causes for age-related degeneration include lack of IVD nutrition and prolonged intradiscal pressure. While studies have shown changes in cervical intradiscal pressure (CIDP) with cervical range of motion (ROM), traction and manipulation, no study has evaluated effects of cervical spine joint mobilizations on CIDP. Design Intraclass correlation coefficient [ICC (3,k)] was calculated. To assess the effect of cervical mobilizations on CIDP at different time intervals, four separate 3 (TIME: before/during/immediately following mobilization) X 2 (25 N and 45 N) repeated measures ANOVAs (Friedman) were used for each cervical level. Setting Department of Anatomy at the Université du Québec à Trois-Rivières. Participants Seven un-embalmed cadaveric specimens. Interventions Cervical PA mobilizations on cadaveric specimens using a servo-controlled linear actuator to provide 25 and 45 N forces. Measurements of CIDP were conducted using fiberoptic catheter systems at C4-5, C5-6, C6-7, and C7-T1 IVD levels. The FISO system recorded CIDP for each IVD cervical level before, during and immediately following mobilization. Main Outcome Measures Measurements of CIDP including means, standard deviation and medians. Results Reliability coefficients for CIDP measurements during, immediately after mobilization were ICC(3,k)>.98, 95% CI. Mean CIDP varied from -7.3±18.8 to 11±37.9 mmHg and from -6.5±16 to 22.8±84.5 mmHg during 25 and 45N PA mobilizations (p>.4), respectively. There was no CIDP changes during and following PA mobilizations, with exception of C5-6 CIDP at 25N or 45N (p=.05 and .018, respectively). Conclusions Cervical PA mobilizations produced substantial CIDP changes at adjacent and remote cervical segments. In vivo investigations are warranted. Author(s) Disclosures No disclosures or conflicts noted. To investigate in cadaveric specimens if cervical PA mobilizations produce changes in CIDP. Causes for age-related degeneration include lack of IVD nutrition and prolonged intradiscal pressure. While studies have shown changes in cervical intradiscal pressure (CIDP) with cervical range of motion (ROM), traction and manipulation, no study has evaluated effects of cervical spine joint mobilizations on CIDP. Intraclass correlation coefficient [ICC (3,k)] was calculated. To assess the effect of cervical mobilizations on CIDP at different time intervals, four separate 3 (TIME: before/during/immediately following mobilization) X 2 (25 N and 45 N) repeated measures ANOVAs (Friedman) were used for each cervical level. Department of Anatomy at the Université du Québec à Trois-Rivières. Seven un-embalmed cadaveric specimens. Cervical PA mobilizations on cadaveric specimens using a servo-controlled linear actuator to provide 25 and 45 N forces. Measurements of CIDP were conducted using fiberoptic catheter systems at C4-5, C5-6, C6-7, and C7-T1 IVD levels. The FISO system recorded CIDP for each IVD cervical level before, during and immediately following mobilization. Measurements of CIDP including means, standard deviation and medians. Reliability coefficients for CIDP measurements during, immediately after mobilization were ICC(3,k)>.98, 95% CI. Mean CIDP varied from -7.3±18.8 to 11±37.9 mmHg and from -6.5±16 to 22.8±84.5 mmHg during 25 and 45N PA mobilizations (p>.4), respectively. There was no CIDP changes during and following PA mobilizations, with exception of C5-6 CIDP at 25N or 45N (p=.05 and .018, respectively). Cervical PA mobilizations produced substantial CIDP changes at adjacent and remote cervical segments. In vivo investigations are warranted.

Comparison of venous hemoglobin saturation measurements obtained by in vivo oximetry and calculated from blood gas analysis in critically ill dogs

To compare in vivo central venous hemoglobin saturation measurement (ScvO2 ) using a fiber optic catheter with saturation calculated from blood gas analysis in critically ill dogs. Prospective observational study. University veterinary teaching hospital intensive care unit. A convenience sample of 20 dogs with severe illness. Dogs were instrumented with either a central venous catheter with an integrated fiber optic cable or a conventional catheter with a fiber optic probe inserted through its distal port. Baseline saturation was measured with the fiber optic system (FSO2 ), then monitored continuously. Central venous blood was collected for analysis and FSO2 was recorded by the principal investigator (PI) or nursing staff participating in data collection (staff) at baseline and at 1, 2, 3, and 6 hours. Hemoglobin oxygen saturation (SO2 ) values calculated using human Bohr coefficients were taken directly from the analyzer (GPSO2 ), and were also calculated using temperature-correction and canine Bohr coefficients (RSO2 ). Ninety-seven paired measurements from 20 dogs were analyzed. FSO2 obtained by the PI (n = 41) had better agreement with both GPSO2 (concordance correlation coefficient ρc = 0.926 vs 0.5562) and RSO2 (ρc = 0.75 for PI vs 0.54) than did staff (n = 56). RSO2 values were always smaller than GPSO2 . FSO2 - GPSO2 differences were smaller when measurements were collected by the PI versus Staff (mean difference 0.21 vs -6.6, respectively, P<0.02). Thirty-six of 41 FSO2 values obtained by PI were within 5% of GPSO2 . Concordance between FSO2 and either calculation method was low, but was better when performed by PI. The larger difference between methods when using RSO2 suggests a positive bias by FSO2 . Difficulty obtaining stable measurements may have contributed to the poor concordance between methods within Staff.

Acute effects of laser myocardial ablation in &lt;i&gt;ex vivo&lt;/i&gt; and &lt;i&gt;in vivo&lt;/i&gt;

Aim. To study and compare the lesions characteristics of laser energy in heart ex vivo and in experimental large animals.Materials and methods. For the ex vivo experiment a pig heart was obtained from a local slaughterhouse. Laser applications were applied using power 15-30 W in the left and right ventricles 5-50 seconds in duration. Immediately after ablation, examination was performed to determine myocardial damage characteristics at each point. In the experimental study, 7 sheep were included, laser applications were performed under fluoroscopic control in the right atrium with power 10, 15 and 20 W, 10-25 s; in the right ventricle 20, 25 and 30 W for 10-40 s; and in the left ventricle 20, 25 and 30 W for 20-40 s. The animals were euthanized and macroscopic examination of laser lesions was performed.Results. A total of 27 laser applications were performed on the heart ex vivo, all lesions were visualized as white spots on the endocardial surface. The maximum lesion depth was 9 mm achieved when using 20 W /50 s, the maximum lesion diameter was 6 mm, when using 25 W /40 s. The minimum lesion diameter and depth were observed when using 30 W /5 s, 2x1 mm. A total of 48 laser applications were performed in experimental animals, in one experimental animal was observed a transmural lesion in the right atrium when using 15 W /20 s. In 3 out of 7 experimental animals, transmural lesions were observed in the right ventricle when using 20 W /30 s; 20 W /40 s and 30 W /10 s. In the left ventricle, transmural lesions were observed in 2 animals, using 15 W /20 s and 20 W /40 s. In the ex vivo study, there was a strong positive correlation between ablation energy and lesion depth (R=0.91, P&lt;0.05) and lesion volume (R=0.73, P&lt;0.05); while there was no such statistical correlation in vivo.Conclusions. Laser ablation 15-20 W for 15-40 s seems to be optimal for achieving the deepest lesions in the atrium and ventricular myocardium. In our small pilot study with fiberoptic catheter ablation on a beating heart there was no correlation between energy delivered and the depth and volume of necrotic myocardium.

Anesthetic management and outcomes for MRI-guided laser interstitial thermal therapy (LITT) for seizure focus in pediatrics: A single-centre experience with 10 consecutive patients.

MRI-guided laser interstitial thermal therapy (LITT) is a stereotactically guided percutaneous minimally invasive procedure, which delivers light energy to tissue via a fiberoptic catheter, resulting in selective thermal ablation. Its use in drug-resistant epilepsy has increased because safety and efficacy have been well-established in adult and pediatric populations 1-4 . The anesthetic management of this procedure in children has not been previously reported. In our pediatric institution, MRI guided LITT is performed using the Visualase™ system (Medtronic, Minneapolis, MN). The typical procedural flow is described in Figure 1.

Low-cost, ultracompact handheld optical coherence tomography probe for in vivo oral maxillofacial tissue imaging.

.Significance: Optical coherence tomography (OCT) has proven useful for detecting various oral maxillofacial abnormalities. To apply it to clinical applications including biopsy guidance and routine screening, a handheld imaging probe is indispensable. OCT probes reported for oral maxillofacial imaging were either based on a bulky galvanometric mirror pair (not compact or long enough) or a distal-end microelectromechanical systems (MEMS) scanner (raised safety concerns), or adapted from fiber-optic catheters (ill-suited for oral cavity geometry).Aim: To develop a handheld probe featuring great compactness and excellent maneuverability for oral maxillofacial tissue imaging.Approach: A dual-axis MEMS scanner was deployed at the proximal end of the probe and the scanned beam was relayed to the distal end through a 4f configuration. Such design provides both a perfect dual-axis telecentric scan and excellent compactness.Results: A handheld probe with a rigid part 70 mm in length and 7 mm in diameter and weighing 25 g in total was demonstrated through both ex vivo and in vivo experiments, including structural visualization of various oral maxillofacial tissues and monitoring the recovery process of an oral mucosa canker sore.Conclusions: The proposed probe exhibits excellent maneuverability and imaging performance showing great potential in clinical applications.

3:54 PM Abstract No. 196 Molecularly targeted photothermal ablation enhances the effect of anti-PD1 therapy in a mouse model of hepatocellular carcinoma

Recent clinical studies have shown that immunotherapy approaches to exploit the full potential of the adaptive immune system to control hepatocellular carcinoma (HCC) progression need improvement. Here, we sought to assess the effect of combining immune checkpoint blockade strategies with a novel molecularly targeted photothermal ablation (MTPA) modality for the treatment of HCC using a mouse model. C3H mice were treated via oral gavage with CCl4 (20% vol/vol) for 12 weeks to induce liver cirrhosis. The mice then received implantations of syngeneic HCA-1 cells in the liver (5x106). 12 days after, the animals were randomly assigned to 4 different treatment groups: (1) untreated (n = 2), (2) MTPA only (n = 3), (3) anti-mouse PD1 antibody only (n = 4, 100μg per I.P. injection every 3 days), and (4) MTPA+anti-PD1 (n = 2). MTPA was performed following an I.V. injection of 0.5 mg/kg indocyanine green (ICG), and by illuminating the tumor with a 785nm near infrared laser coupled to a clinical fiberoptic catheter. The mice underwent T2 MRI on POD-13, and tissues were harvested on POD-14. Tumor sections were processed for histology and for characterization of tumor-infiltrating lymphocytes (TILs) through flow cytometry. Masson’s trichrome stain demonstrated extensive liver cirrhosis at the time of tumor implantation. MRI and histology data showed cases of nodular and diffuse infiltrative HCC. Characterization of TILs showed that MTPA increases the CD3+ population and, when used in combination with anti-PD1, together they increase the number of CD8+ cells while reducing the number of CD4+/FoxP3+ cells (Tregs). Our preliminary results indicate that even in the context of impaired liver function, the combination of anti-PD1 therapy with our novel MTPA has a synergistic effect whereby greater numbers of cytotoxic lymphocytes infiltrate the hepatic tumors, while at the same time decreasing the presence of immunosuppressive cells. Longer follow-up should reveal how these changes in the TILs impact disease progression in both nodular and diffuse infiltrative HCC subtypes.

Correlation of synovial caspase-3 concentration and the photodynamic effectiveness in osteoarthritis treatment.

The present study focuses on investigation of Intra-articular PDT mechanisms for OA treatment. Also, a search for determination of the most effective dose of chlorin e6 (Ce6) for anti-inflammatory PDT of OA was carried out. The study was carried out on laboratory animals (11 Chinchilla rabbits, 1 year, 2.5 kg) with a gonarthritis model of post-traumatic OA. According to the instructions for using Photoditazin (Ce6 based PS) for PDT of human oncological and non-oncological diseases, the recommended dose is 0.7-1.2 mg/kg. For studies on rabbits, taking into account the conversion coefficient (3.2), the PS doses of 2.4, 3.2 and 6.4 mg/kg were selected. Fluorescence spectra were measured intra-articular before and after PDT using spectrometer with fiber-optic probe. The intrajoint PDT was carried out using a laser (662 ± 10 nm) and a fiber-optic catheter with a cylindrical diffuser inside a sapphire needle for a uniform distribution of the laser radiation. The immunohistochemical study was carried out by staining the samples with caspase-3. Histological and immunohistochemical analysis showed that the best PS dose for intravenous administration for PDT of rabbit gonarthritis is 3.2 mg/kg. The PS concentration directly in the synovial tissue was 0.5 mg/kg, and this was enough to achieve the most positive results to reduce the caspase-3 level. The caspase-3 level correlates well with other signs of inflammation in the synovial membrane (edema, etc.). Therefore, to assess the PDT effectiveness in the treatment of gonarthritis accompanied by synovitis, it is sufficient to analyze only for caspase-3. The efficacy of PDT with Ce6 showed that 3.2 mg/kg PS dose (1 mg/kg for a human) is the most effective.

SCIDOT-50. A RAT MODEL FOR LASER INTERSTITIAL THERMAL THERAPY FOR GLIOBLASTOMA: EFFECTS ON PERI-ABLATION BLOOD-BRAIN BARRIER AND IMPLICATIONS FOR POST-ABLATION CHEMOTHERAPY

Abstract Laser interstitial thermal therapy (LITT) is a minimally invasive tumor cytoreductive treatment for recurrent gliomas, brain tumors in eloquent regions or otherwise inaccessible to traditional open surgery. LITT offers quicker recovery and shorter hospital stays as additional advantages. A laser fiberoptic catheter is positioned in the body of the tumor under magnetic resonance imaging (MRI) guidance via a twist drill hole in the skull. Using MR thermometry, the tumor is ablated by laser heating to lethal temperatures. The peri-ablation zones get heated to sub-lethal temperatures and subsequently recover. It has been reported in humans that opening of the blood-brain barrier (BBB) occurs, lasting several weeks after ablation. We have adapted Visualase®, a clinically available LITT system, for use in a rat glioblastoma model. Athymic female rats (n=7) were implanted with U251 tumor cells in one brain hemisphere. Tumor growth was monitored using MRI. When tumors reached about 4 mm in diameter, they were ablated under supervision of MR diffusion-weighted MRI, sparing the surrounding normal brain tissue. Contrast-enhanced MRI data were obtained before LITT, immediately after and at post-LITT 24 h. The brains were processed for histopathology and stained with hematoxylin and eosin (H&amp;E) for visualizing the extent of the tumor and for major histocompatibility complex (MHC) to identify the human-derived U251 cells. All rats survived the LITT procedure. A ring of contrast enhancement around ablation perimeter was observed immediately after, and also at 24 h. H&amp;E data showed near-complete ablation of the tumors. However, MHC staining showed U251 cells still remaining in the ablation vicinity. These data suggest this model is useful for examining the temporal and spatial development of peri-ablation BBB opening following LITT. Concurrent timing of post-ablation chemotherapy to the development and presence of post-LITT BBB opening may aid in efficient targeting of remaining tumor cells.

A comparison between the Disposcope endoscope and fibreoptic bronchoscope for nasotracheal intubation: a randomized controlled trial

BackgroundNasotracheal intubation (NTI) is frequently performed for oral and maxillofacial surgeries. This study evaluated whether NTI is easier when guided by Disposcope endoscopy or fibreoptic bronchoscopy.MethodsSixty patients (30 per group) requiring NTI were randomly assigned to undergo fibreoptic bronchoscopy-guided (fibreoptic group) or Disposcope endoscope-guided (Disposcope group) NTI. The NTI time, which was defined as the time from when the fibreoptic bronchoscope or aseptic suction catheter was inserted into the nasal cavity to the time at which the tracheal tube was correctly inserted through the glottis, was recorded. Epistaxis was evaluated by direct laryngoscopy five minutes after completing NTI and was scored as one of four grades according to the following modified criteria: no epistaxis, mild epistaxis, moderate epistaxis, and severe epistaxis.ResultsThe time to complete NTI was significantly longer in the fibreoptic group than in the Disposcope group (38.4 s vs 24.1 s; mean difference, 14.2 s; 95% confidence interval (CI), 10.4 to 18.1). Mild epistaxis was observed in 8 patients in the fibreoptic group and in 7 patients in the Disposcope group (26.7% vs 23.3%, respectively; relative risk, 1.2; 95% CI, 0.4 to 3.9), though no moderate or severe epistaxis occurred in either group. Furthermore, no obvious nasal pain was reported by any of the patients at any time point after extubation (P = 0.74).ConclusionNTI can be completed successfully using either fibreoptic bronchoscopy or Disposcope endoscope as a guide without any severe complications. However, compared to fibreoptic bronchoscopy, Disposcope endoscope requires less execution time (the NTI time).Trial registrationThis clinical research was registered at the Chinese Clinical Trial Registry (www.chictr.org.cn, ChiCTR-IPR-17011462, date of registration, May 2017).

Intra-Aortic Balloon Pump for Patients with Cardiac Conditions: An Update on Available Techniques and Clinical Applications

In this paper, we present a review of the intra-aortic balloon pump, as well as the usage of it in the medical field today. An intra-aortic balloon pump (IABP) is a biomedical device that can assist the heart during unstable angina or after a heart attack. This pump is typically used in patients who suffer from ischemia of the heart tissue, due to an unbalanced level of myocardial oxygen supply or demand. Through counterpulsation, which is a technique to synchronize the external pumping of blood with the heart’s cycle, the device can balance the supply and demand of blood that is necessary for the heart to pump properly. The IABP is comprised of the following four components: a polyurethane balloon, a polyethylene or fiber-optic catheter, a transducer, and the intra-aortic balloon pump console. In the past, researchers have used other materials that have low biocompatibility and can cause complications within the body. This analysis will explain the complications and state changes that occurred due to them. Limitations of past designs and advantages of current designs will be acknowledged, for they can be used by researchers to enhance designs for the future. Consequently, the analysis of this device may lead to improved designs and treatment in the future for patients with cardiac conditions.

Interventional Radiology Percutaneous Liver Biopsy Pediatric Nursing Guidelines

Critically ill patients with brain injury often need intracranial pressure (ICP) monitoring. The two most common methods of ICP monitoring are via an external ventricular drain (EVD) catheter and via an intraparenchymal fiberoptic catheter. In addition to ICP monitoring, an EVD has the additional advantage of being able to treat hydrocephalus or lower elevated ICP by cerebrospinal fluid drainage. In addition to ICP monitoring, frequent radiographic imaging is also considered to be a fundamental component of neurological multimodal monitoring. As such, patients with EVDs often require intrahospital transport for advanced imaging. There are currently no national or international standards guiding intrahospital transport to and from the radiology suite. We use a fictional case to describe practice patterns and variations that may improve care of the patient with EVDs during transport to radiology. The fundamentals for ICP monitoring are highlighted, and an emphasis is placed on clear and concise communication.

Adjusting cardiopulmonary bypass flow or arterial pressure to maintain renal medullary oxygen

Cardiopulmonary bypass leads to renal hypoperfusion, resulting in medullary hypoxia and acute kidney injury. In instrumented sheep subjected to cardiopulmonary bypass, Lankadeva etal. found that medullary perfusion and tissue oxygen tension (PO2) was maintained at low-dose metaraminol, an α1-adrenoceptor agonist, because low-dose metaraminol increased perfusion pressure without affecting renal vascular resistance. Lankadeva etal. developed a fiber-optic catheter to measure bladder urine PO2. Urine PO2 tracks medullary PO2, and low urine PO2 predicts acute kidney injury. Adjusting cardiopulmonary bypass to maintain urine PO2 may help avoid acute kidney injury.

Intra-cardiac Side-Firing Light Catheter for Monitoring Cellular Metabolism using Transmural Absorbance Spectroscopy of Perfused Mammalian Hearts.

Absorbance spectroscopy of cardiac muscle provides non-destructive assessment of cytosolic and mitochondrial oxygenation via myoglobin and cytochrome absorbance respectively. In addition, numerous aspects of the mitochondrial metabolic status such as membrane potential and substrate entry can also be estimated. To perform cardiac wall transmission optical spectroscopy, a commercially available side-firing optical fiber catheter is placed in the left ventricle of the isolated perfused heart as a light source. Light passing through the heart wall is collected with an external optical fiber to perform optical spectroscopy of the heart in near real- time. The transmission approach avoids numerous surface scattering interference occurring in widely used reflection approaches. Changes in transmural absorbance spectra were deconvolved using a library of chromophore reference spectra, providing quantitative measures of all the known cardiac chromophores simultaneously. This spectral deconvolution approach eliminated intrinsic errors that may result from using common dual wavelength methods applied to overlapping absorbance spectra, as well as provided a quantitative evaluation of the goodness of fit. A custom program was designed for data acquisition and analysis, which permitted the investigator to monitor the metabolic state of the preparation during the experiment. These relatively simple additions to the standard heart perfusion system provide a unique insight into the metabolic state of the heart wall in addition to conventional measures of contraction, perfusion, and substrate/oxygen extraction.

Safeguarding Medication Administration in Radiology

Critically ill patients with brain injury often need intracranial pressure (ICP) monitoring. The two most common methods of ICP monitoring are via an external ventricular drain (EVD) catheter and via an intraparenchymal fiberoptic catheter. In addition to ICP monitoring, an EVD has the additional advantage of being able to treat hydrocephalus or lower elevated ICP by cerebrospinal fluid drainage. In addition to ICP monitoring, frequent radiographic imaging is also considered to be a fundamental component of neurological multimodal monitoring. As such, patients with EVDs often require intrahospital transport for advanced imaging. There are currently no national or international standards guiding intrahospital transport to and from the radiology suite. We use a fictional case to describe practice patterns and variations that may improve care of the patient with EVDs during transport to radiology. The fundamentals for ICP monitoring are highlighted, and an emphasis is placed on clear and concise communication.

Pelvic Congestion Syndrome

Critically ill patients with brain injury often need intracranial pressure (ICP) monitoring. The two most common methods of ICP monitoring are via an external ventricular drain (EVD) catheter and via an intraparenchymal fiberoptic catheter. In addition to ICP monitoring, an EVD has the additional advantage of being able to treat hydrocephalus or lower elevated ICP by cerebrospinal fluid drainage. In addition to ICP monitoring, frequent radiographic imaging is also considered to be a fundamental component of neurological multimodal monitoring. As such, patients with EVDs often require intrahospital transport for advanced imaging. There are currently no national or international standards guiding intrahospital transport to and from the radiology suite. We use a fictional case to describe practice patterns and variations that may improve care of the patient with EVDs during transport to radiology. The fundamentals for ICP monitoring are highlighted, and an emphasis is placed on clear and concise communication.