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Samineni AV, Eklund SE, Miller PE, Buxton K, Snyder BD, Matheney TH, Watkins CJ, Stone SSD, Alrayashi W, Brusseau R, Shore BJ. Epidural Analgesia Versus Lumbar Plexus Blockade After Hip Reconstruction Surgery in Children With Cerebral Palsy and Intrathecal Baclofen Pumps: A Comparison of Safety and Efficacy. J Pediatr Orthop 2022; 42:222-228. [PMID: 35051954 DOI: 10.1097/bpo.0000000000002056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Epidural analgesia is commonly used for pain control after reconstructive hip surgery, but its use is controversial in the presence of an intrathecal baclofen pump (ITB). The purpose of this retrospective study was to investigate the rate of serious anesthetic and postoperative complications as well as the efficacy of epidural analgesia compared with lumbar plexus blocks (LPBs) for pain management after neuromuscular hip reconstruction in children with cerebral palsy (CP) and ITB. METHODS Pediatric patients with CP and ITB undergoing hip reconstructive surgery from 2010 to 2019 were retrospectively identified. Patients receiving epidural analgesia were compared with those receiving LPB. Morphine milligram equivalents per kilogram were used as a surrogate measure for pain-related outcomes, as pain scores were reported with wide ranges (eg, 0 to 5/10), making it unfeasible to compare them across the cohort. Postoperative complications were graded using the modified Clavien-Dindo classification. RESULTS Forty-four patients (26/44, 59% male) underwent surgery at an average age of 10.3 years (SD=3.4 y, range: 4 to 17 y). The majority utilized LPB (28/44, 64%) while the remaining utilized epidural (16/44, 36%). There were no differences in rates of serious complications, including no cases of ITB malfunction, damage, or infection. During the immediate postoperative course, patients who received LPB had higher morphine milligram equivalents per kilogram requirements than patients who received epidural analgesia. CONCLUSIONS In patients with CP undergoing hip reconstruction surgery with an ITB in situ, epidural anesthesia was associated with improved analgesia compared with LPB analgesia, with a similar risk for adverse outcomes. Epidural catheters placed using image-guided insertion techniques can avoid damage to the ITB catheter while providing effective postoperative pain control without increasing rates of complications in this complex patient population. LEVEL OF EVIDENCE Level III.
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Eklund SE, Staffa SJ, Alrayashi W, Brusseau RR. COVID-19 pandemic as impetus for sustained utilization of home peripheral nerve catheter program. Paediatr Anaesth 2022; 32:482-484. [PMID: 34923711 DOI: 10.1111/pan.14383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 12/04/2021] [Accepted: 12/14/2021] [Indexed: 11/30/2022]
Affiliation(s)
- Susan E Eklund
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts, USA
| | - Steven J Staffa
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts, USA
| | - Walid Alrayashi
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts, USA
| | - Roland R Brusseau
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts, USA
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Eklund SE. Perioperative evaluation of direct-to-consumer genetic testing results. Paediatr Anaesth 2021; 31:619-620. [PMID: 33844374 DOI: 10.1111/pan.14149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 01/18/2021] [Accepted: 01/28/2021] [Indexed: 12/01/2022]
Affiliation(s)
- Susan E Eklund
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
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Abstract
BACKGROUND Neuraxial anaesthesia for lower extremity total joint replacement surgery has several advantages over general anaesthesia; however, we encountered resistance to routine use of spinal anaesthesia and standardised analgesic regimens at our large, tertiary hospital. Our Perioperative Surgical Home led to multidisciplinary education and enhanced communication to change practice, with the purpose of increasing rates of neuraxial anaesthetics for these surgeries. METHODS Team members from anaesthesia, nursing and surgery participated in the development and adoption of the care pathway. After implementation, we performed a retrospective analysis to examine the impact of the pathway on primary anaesthetic choice. Data were analysed using Student's t-test and interrupted time series analysis. RESULTS The rate of neuraxial anaesthetics increased following implementation of the total joint pathway. CONCLUSION With multidisciplinary collaboration, we were able to change practice towards spinal anaesthesia, despite a large and diverse group of practitioners.
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Affiliation(s)
- Susan E Eklund
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital & Harvard Medical School, Boston, MA, USA
| | - Alina Vodonos
- Clinical Research Center Soroka University Medical Center, Beersheva, Israel
| | - Sheila M Ryan-Barnett
- Department of Anesthesia, Critical Care, and Pain Medicine, Beth Israel Deaconess Medical Center & Harvard Medical School, Boston, MA, USA
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Eklund SE, Samineni AV, Koka A, Riley BL, Brusseau RR, Shore BJ, Miller PE, Stone SS, Berde CB, Alrayashi W. Epidural catheter placement in children with baclofen pumps. Paediatr Anaesth 2021; 31:178-185. [PMID: 33135307 DOI: 10.1111/pan.14061] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 10/15/2020] [Accepted: 10/22/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND Children with cerebral palsy often suffer from increased tone, which can be treated with intrathecal baclofen via implanted pump. Additionally, they often require major orthopedic surgery for hip reconstruction; however, the presence of an intrathecal baclofen pump is a relative contraindication to regional anesthesia due to concerns about damaging the intrathecal baclofen pump system. AIMS (a) To evaluate adverse events related to placing epidural catheters in children with intrathecal baclofen pumps and (b) describe our multidisciplinary approach to the care of these complex patients. METHODS Children with cerebral palsy and intrathecal baclofen pump in situ who underwent hip reconstruction between 2010 and 2019 and had a perioperative epidural placed were reviewed retrospectively. Charts were assessed for adverse events or intrathecal baclofen complications. Fluoroscopic images were reviewed to evaluate the proximity between epidural and intrathecal baclofen catheters. The process of coordinating multiple services was examined. RESULTS Sixteen children met the inclusion criteria. There were no major complications following epidural placement. Postoperative pump interrogation was normal for all patients. Fluoroscopy was utilized for 9/16 (56%) epidural procedures. Epidurogram was used to confirm 11/16 catheters (68%). Children with an intrathecal baclofen pump were identified by orthopedic surgeons at the time of surgical booking and referred to the regional anesthesia team for review. The neurosurgical, pain, and regional anesthesia teams determined the appropriateness and safety of approaching the neuraxis. Pain and/or regional anesthesiologists with competency in spine fluoroscopy were scheduled on the day of surgery for fluoroscopically guided epidural placement. Postoperatively, catheters were managed by the acute pain team. Intrathecal baclofen pumps were interrogated by the baclofen pump team prior to patient discharge. DISCUSSION In this case series, not only was epidural placement feasible but also there were no observed complications. This work highlights the importance of a multidisciplinary approach to complex regional anesthetic techniques, as well as the importance of basic competency in spine fluoroscopy for regional anesthesiologists.
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Affiliation(s)
- Susan E Eklund
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Aneesh V Samineni
- Department of Orthopedic Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Anjali Koka
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Bobbie L Riley
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Roland R Brusseau
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Benjamin J Shore
- Department of Orthopedic Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Patricia E Miller
- Department of Orthopedic Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Scellig S Stone
- Department of Neurosurgery, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Charles B Berde
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Walid Alrayashi
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
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Roy N, Brown ML, Parra MF, Sleeper LA, Alrayashi W, Nasr VG, Eklund SE, Cravero JP, Del Nido PJ, Brusseau R. Bilateral Erector Spinae Blocks Decrease Perioperative Opioid Use After Pediatric Cardiac Surgery. J Cardiothorac Vasc Anesth 2020; 35:2082-2087. [PMID: 33139160 DOI: 10.1053/j.jvca.2020.10.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 10/03/2020] [Accepted: 10/06/2020] [Indexed: 11/11/2022]
Abstract
OBJECTIVE The present study examined the feasibility and efficacy of continuous bilateral erector spinae blocks for post-sternotomy pain in pediatric cardiac surgery. DESIGN Prospective cohort study; patients were retrospectively matched 1:2 to control patients. Conditional logistic regression was used to compare dichotomous outcomes, and generalized linear models were used for continuous measures, both accounting for clusters. SETTING Quaternary children's hospital, university setting. PARTICIPANTS The study comprised 10 children ages five-to-17 years undergoing elective cardiac surgery requiring cardiopulmonary bypass. INTERVENTIONS Ultrasound-guided bilateral erector spinae blocks at the conclusion of the cardiac surgical procedure, with postoperative infusion of ropivacaine until chest tube removal. Postoperative management otherwise followed standardized guidelines. MEASUREMENTS AND MAIN RESULTS Patient characteristics were similar in the two groups. The median time to completion of the bilateral blocks was 16.0 minutes (interquartile range [IQR] 14.8-19.3), and no major adverse events were identified. Pain scores were low in both groups. Postoperative opioid use at 48 hours, rendered as oral morphine equivalents, was significantly reduced in the patients receiving the blocks. Cluster-adjusted squared-root-transformed means ± standard error were 0.89 ± 0.06 mg/kg for patients receiving the blocks versus 1.05 ± 0.06 mg/kg for control patients (p = 0.04; raw medians 0.81 [IQR 0.41-1.04] v 1.10 [IQR 0.78-1.35] mg/kg, respectively). There were no differences in recovery metrics, length of stay, or complications. CONCLUSIONS Bilateral erector spinae blocks were associated with a reduction in opioid use in the first 48 hours after pediatric cardiac surgery compared with a matched cohort from the enhanced recovery program. Larger studies are needed to determine whether this can result in an improvement in recovery and patient satisfaction.
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Affiliation(s)
- Nathalie Roy
- Department of Cardiac Surgery, Boston Children's Hospital, Boston, MA; Harvard Medical School, Boston, MA.
| | - Morgan L Brown
- Harvard Medical School, Boston, MA; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, MA
| | - M Fernanda Parra
- Department of Cardiac Surgery, Boston Children's Hospital, Boston, MA; Harvard Medical School, Boston, MA
| | - Lynn A Sleeper
- Harvard Medical School, Boston, MA; Department of Cardiology, Boston Children's Hospital, Boston, MA
| | - Walid Alrayashi
- Harvard Medical School, Boston, MA; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, MA
| | - Viviane G Nasr
- Harvard Medical School, Boston, MA; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, MA
| | - Susan E Eklund
- Harvard Medical School, Boston, MA; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, MA
| | - Joseph P Cravero
- Harvard Medical School, Boston, MA; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, MA
| | - Pedro J Del Nido
- Department of Cardiac Surgery, Boston Children's Hospital, Boston, MA; Harvard Medical School, Boston, MA
| | - Roland Brusseau
- Harvard Medical School, Boston, MA; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, MA
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Eklund SE, Levin DN. Lung Isolation for Whole Lung Lavage in a Pediatric Patient With Atypical Airway Anatomy due to Short Stature: A Case Report. A A Pract 2020; 13:253-256. [PMID: 31265442 DOI: 10.1213/xaa.0000000000001044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
This case demonstrates the airway management of a pediatric patient with short stature due to STAT5b deficiency, a rare genetic immunodeficiency associated with lung disease and endocrinopathy. The patient had recurrent pulmonary infections and pulmonary alveolar proteinosis (PAP) for which whole lung lavage (WLL) was recommended. Due to short stature and overall body habitus, the patient's airway would not accommodate a traditional double-lumen tube (DLT). Therefore, we placed 2 single-lumen breathing tubes: 1 endobronchial and 1 endotracheal, to mimic a DLT and facilitate WLL, demonstrating a viable option for lung isolation in the absence of purpose-built equipment.
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Affiliation(s)
- Susan E Eklund
- From the Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - David N Levin
- Department of Anesthesia and Pain Medicine, Hospital for Sick Children (SickKids), University of Toronto, Toronto, Ontario, Canada
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Camelo CR, Eklund SE, Brusseau R, Gomez-Morad AD. Ischemic pain not masked by regional anesthesia. Reg Anesth Pain Med 2019; 45:244-245. [PMID: 31366575 DOI: 10.1136/rapm-2019-100659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 07/01/2019] [Accepted: 07/15/2019] [Indexed: 11/04/2022]
Affiliation(s)
- Carlos Rafael Camelo
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts, USA
| | - Susan E Eklund
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA .,Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts, USA
| | - Roland Brusseau
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts, USA
| | - Andrea D Gomez-Morad
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts, USA
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Moskowitz A, Hansen RM, Eklund SE, Fulton AB. Electroretinographic (ERG) responses in pediatric patients using vigabatrin. Doc Ophthalmol 2012; 124:197-209. [PMID: 22426576 DOI: 10.1007/s10633-012-9320-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 03/02/2012] [Indexed: 11/30/2022]
Abstract
The antiepileptic drug vigabatrin is known to cause retinal and visual dysfunction, particularly visual field defects, in some patients. Electroretinography (ERG) is used in an attempt to identify adverse effects of vigabatrin (VGB) in patients who are not candidates for conventional perimetry. We report data from 114 pediatric patients taking VGB referred for clinical evaluation; median age at test was 22.9 (2.4 to 266.1) months, and median duration of VGB use was 9.7 (0.3 to 140.7) months. Twenty-seven of them were tested longitudinally (3 to 12 ERG tests). ERG responses to full-field stimuli were recorded in scotopic and photopic conditions, and results were compared to responses from healthy control subjects. We found that abnormalities of photoreceptor and post-receptor ERG responses are frequent in these young patients. The most frequently abnormal scotopic parameter was post-receptor sensitivity, log σ, derived from the b-wave stimulus-response function; the most frequently abnormal photopic parameter was the implicit time of the OFF response (d-wave) to a long (150 ms) flash. Abnormal 30-Hz flicker response amplitude, previously reported to be a predictor of visual field loss, occurred infrequently. For the group as a whole, none of the ERG parameters changed significantly with increasing duration of VGB use. Four of the 27 patients tested longitudinally showed systematic worsening of log σ with duration of VGB use. In a subset of patients who underwent perimetry (N = 39), there was no significant association of any ERG parameter with visual field defects. We cannot determine whether the ERG abnormalities we found were due solely to the effects of VGB. We caution against over-reliance on the ERG to monitor pediatric patients for VGB toxicity and recommend further development of a reliable test of peripheral vision to supplant ERG testing.
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Affiliation(s)
- Anne Moskowitz
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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Moskowitz A, Hansen RM, Akula JD, Eklund SE, Fulton AB. Rod and rod-driven function in achromatopsia and blue cone monochromatism. Invest Ophthalmol Vis Sci 2008; 50:950-8. [PMID: 18824728 DOI: 10.1167/iovs.08-2544] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
PURPOSE To evaluate rod photoreceptor and postreceptor retinal function in pediatric patients with achromatopsia (ACHR) and blue cone monochromatism (BCM) using contemporary electroretinographic (ERG) procedures. METHODS Fifteen patients (age range, 1-20 years) with ACHR and six patients (age range, 4-22 years) with BCM were studied. ERG responses to full-field stimuli were obtained in scotopic and photopic conditions. Rod photoreceptor (S(rod), R(rod)) and rod-driven postreceptor (log sigma, V(max)) response parameters were calculated from the a-wave and b-wave. ERG records were digitally filtered to demonstrate the oscillatory potentials (OPs); a sensitivity parameter, log SOPA(1/2), and an amplitude parameter, SOPA(max), were used to characterize the OP response. Response parameters were compared with those of 12 healthy control subjects. RESULTS As expected, photopic responses were nondetectable in patients with ACHR and BCM. In addition, mean scotopic photoreceptor (R(rod)) and postreceptor (V(max) and SOPA(max)) amplitude parameters were significantly reduced compared with those in healthy controls. The flash intensity required to evoke a half-maximum b-wave amplitude (log sigma) was significantly increased. CONCLUSIONS Results of this study provide evidence that deficits in rod and rod-mediated function occur in the primary cone dysfunction syndromes ACHR and BCM.
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Affiliation(s)
- Anne Moskowitz
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
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Hansen RM, Eklund SE, Benador IY, Mocko JA, Akula JD, Liu Y, Martinez-Perez ME, Fulton AB. Retinal degeneration in children: dark adapted visual threshold and arteriolar diameter. Vision Res 2008; 48:325-31. [PMID: 17765282 PMCID: PMC2476928 DOI: 10.1016/j.visres.2007.07.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2007] [Revised: 07/13/2007] [Accepted: 07/16/2007] [Indexed: 10/22/2022]
Abstract
To assess the condition of the retina in children with retinal degeneration due to Bardet-Biedl syndrome (BBS, n=41), Leber congenital amaurosis (LCA, n=31), or Usher syndrome (USH, n=13), the dark adapted visual threshold (DAT) and arteriolar diameters were measured. Compared to controls, the initial DATs of nearly all (83/85) were significantly elevated, and in 26/62 with serial DATs, significant progressive elevation occurred. Arteriolar diameters were significantly attenuated and narrowed with age in BBS and USH, but not LCA. Higher DATs were associated with narrower arterioles. Such non-invasive procedures can document the natural history of these retinal diseases and have the potential to assess response to future treatment.
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Affiliation(s)
- Ronald M Hansen
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
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Eklund SE, Chambers JQ, Mamantov G, Diminnie J, Barnes CE. Tungsten fluorides: syntheses and electrochemical characterization in the FLINAK molten salt eutectic. Inorg Chem 2001; 40:715-22. [PMID: 11225114 DOI: 10.1021/ic000491o] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The following tungsten fluorides have been synthesized by simple addition reactions or by reduction with tungsten metal at elevated temperature: KWF7, K2WF8, MWF6 (M = K, Na, Rb, Cs), K2WF7, M3WF8 (M = K, Na, Rb), and K3WF6. The compounds were characterized by their Raman spectra and by cyclic voltammetry in the molten FLINAK eutectic melt (46.5, 11.5, and 42.0 mol % of LiF, NaF, and KF, respectively) at 475-800 degrees C. X-ray crystal structures are reported for two new compounds K2WF7 and K3WF6. The crystals of K2WF7 were orthorhombic, space group Pnma (No. 62) with a = 9.800(2) A, b = 5.7360(11) A, c = 11.723(2) A, and Z = 4. Crystals of K3WF6 were cubic, space group Fm3 (No. 225) with a = b = c = 8.9160(10) A, Z = 4. Electrodeposition of tungsten metal on Pt from FLINAK, prepared by the addition of WF6 gas and metallic tungsten to the melt, is suggested to result from reduction of an equilibrium mixture of WF8(3-) and WF6(3-).
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Affiliation(s)
- S E Eklund
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA
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