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1.
J Vasc Interv Radiol ; 35(7): 1043-1048.e3, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38508449

ABSTRACT

PURPOSE: Treatment of hypovascular tumors, such as pancreatic adenocarcinoma, is challenging owing to inefficient drug delivery. This report examines the potential mechanism of localized drug delivery via transarterial microperfusion (TAMP) using a proprietary adjustable double-balloon occlusion catheter in a porcine model. MATERIALS AND METHODS: Adult Yorkshire swine (N = 21) were used in the Institutional Animal Care & Use Committee-approved protocols. The RC-120 catheter (RenovoRx, Los Altos, California) was positioned into visceral, femoral, and pulmonary arteries with infusion of methylene blue dye, gemcitabine, or gold nanoparticles. Transmural delivery was compared under double-balloon occlusion with and without side-branch exclusion, single-balloon occlusion, and intravenous delivery. Intra-arterial pressure and vascular histologic changes were assessed. RESULTS: Infusion with double-balloon occlusion and side-branch exclusion provided increased intra-arterial pressure in the isolated segment and enhanced perivascular infusate penetration with minimal vascular injury. Infusates were predominantly found in the vasa vasorum by electron microscopy. CONCLUSIONS: TAMP enhanced transmural passage mediated by localized increase in arterial pressure via vasa vasorum.


Subject(s)
Vasa Vasorum , Animals , Vasa Vasorum/pathology , Vasa Vasorum/drug effects , Balloon Occlusion , Gemcitabine , Infusions, Intra-Arterial , Deoxycytidine/analogs & derivatives , Deoxycytidine/administration & dosage , Deoxycytidine/pharmacology , Models, Animal , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/pharmacology , Methylene Blue/administration & dosage , Swine , Metal Nanoparticles , Equipment Design , Arterial Pressure/drug effects , Sus scrofa , Vascular Access Devices
3.
J Med Internet Res ; 21(7): e13143, 2019 07 15.
Article in English | MEDLINE | ID: mdl-31368443

ABSTRACT

BACKGROUND: One reason for the introduction of digital technologies into health care has been to try to improve safety and patient outcomes by providing real-time access to patient data and enhancing communication among health care professionals. However, the adoption of such technologies into clinical pathways has been less examined, and the impacts on users and the broader health system are poorly understood. We sought to address this by studying the impacts of introducing a digitally enabled care pathway for patients with acute kidney injury (AKI) at a tertiary referral hospital in the United Kingdom. A dedicated clinical response team-comprising existing nephrology and patient-at-risk and resuscitation teams-received AKI alerts in real time via Streams, a mobile app. Here, we present a qualitative evaluation of the experiences of users and other health care professionals whose work was affected by the implementation of the care pathway. OBJECTIVE: The aim of this study was to qualitatively evaluate the impact of mobile results viewing and automated alerting as part of a digitally enabled care pathway on the working practices of users and their interprofessional relationships. METHODS: A total of 19 semistructured interviews were conducted with members of the AKI response team and clinicians with whom they interacted across the hospital. Interviews were analyzed using inductive and deductive thematic analysis. RESULTS: The digitally enabled care pathway improved access to patient information and expedited early specialist care. Opportunities were identified for more constructive planning of end-of-life care due to the earlier detection and alerting of deterioration. However, the shift toward early detection also highlighted resource constraints and some clinical uncertainty about the value of intervening at this stage. The real-time availability of information altered communication flows within and between clinical teams and across professional groups. CONCLUSIONS: Digital technologies allow early detection of adverse events and of patients at risk of deterioration, with the potential to improve outcomes. They may also increase the efficiency of health care professionals' working practices. However, when planning and implementing digital information innovations in health care, the following factors should also be considered: the provision of clinical training to effectively manage early detection, resources to cope with additional workload, support to manage perceived information overload, and the optimization of algorithms to minimize unnecessary alerts.


Subject(s)
Health Personnel/psychology , Telemedicine/methods , Female , Humans , Male , Qualitative Research
4.
J Med Internet Res ; 21(7): e13147, 2019 07 15.
Article in English | MEDLINE | ID: mdl-31368447

ABSTRACT

BACKGROUND: The development of acute kidney injury (AKI) in hospitalized patients is associated with adverse outcomes and increased health care costs. Simple automated e-alerts indicating its presence do not appear to improve outcomes, perhaps because of a lack of explicitly defined integration with a clinical response. OBJECTIVE: We sought to test this hypothesis by evaluating the impact of a digitally enabled intervention on clinical outcomes and health care costs associated with AKI in hospitalized patients. METHODS: We developed a care pathway comprising automated AKI detection, mobile clinician notification, in-app triage, and a protocolized specialist clinical response. We evaluated its impact by comparing data from pre- and postimplementation phases (May 2016 to January 2017 and May to September 2017, respectively) at the intervention site and another site not receiving the intervention. Clinical outcomes were analyzed using segmented regression analysis. The primary outcome was recovery of renal function to ≤120% of baseline by hospital discharge. Secondary clinical outcomes were mortality within 30 days of alert, progression of AKI stage, transfer to renal/intensive care units, hospital re-admission within 30 days of discharge, dependence on renal replacement therapy 30 days after discharge, and hospital-wide cardiac arrest rate. Time taken for specialist review of AKI alerts was measured. Impact on health care costs as defined by Patient-Level Information and Costing System data was evaluated using difference-in-differences (DID) analysis. RESULTS: The median time to AKI alert review by a specialist was 14.0 min (interquartile range 1.0-60.0 min). There was no impact on the primary outcome (estimated odds ratio [OR] 1.00, 95% CI 0.58-1.71; P=.99). Although the hospital-wide cardiac arrest rate fell significantly at the intervention site (OR 0.55, 95% CI 0.38-0.76; P<.001), DID analysis with the comparator site was not significant (OR 1.13, 95% CI 0.63-1.99; P=.69). There was no impact on other secondary clinical outcomes. Mean health care costs per patient were reduced by £2123 (95% CI -£4024 to -£222; P=.03), not including costs of providing the technology. CONCLUSIONS: The digitally enabled clinical intervention to detect and treat AKI in hospitalized patients reduced health care costs and possibly reduced cardiac arrest rates. Its impact on other clinical outcomes and identification of the active components of the pathway requires clarification through evaluation across multiple sites.


Subject(s)
Delivery of Health Care/economics , Telemedicine/methods , Female , Humans , Male , Treatment Outcome
5.
F1000Res ; 6: 1033, 2017.
Article in English | MEDLINE | ID: mdl-28751970

ABSTRACT

Acute Kidney Injury (AKI), an abrupt deterioration in kidney function, is defined by changes in urine output or serum creatinine. AKI is common (affecting up to 20% of acute hospital admissions in the United Kingdom), associated with significant morbidity and mortality, and expensive (excess costs to the National Health Service in England alone may exceed £1 billion per year). NHS England has mandated the implementation of an automated algorithm to detect AKI based on changes in serum creatinine, and to alert clinicians. It is uncertain, however, whether 'alerting' alone improves care quality. We have thus developed a digitally-enabled care pathway as a clinical service to inpatients in the Royal Free Hospital (RFH), a large London hospital. This pathway incorporates a mobile software application - the "Streams-AKI" app, developed by DeepMind Health - that applies the NHS AKI algorithm to routinely collected serum creatinine data in hospital inpatients. Streams-AKI alerts clinicians to potential AKI cases, furnishing them with a trend view of kidney function alongside other relevant data, in real-time, on a mobile device. A clinical response team comprising nephrologists and critical care nurses responds to these AKI alerts by reviewing individual patients and administering interventions according to existing clinical practice guidelines. We propose a mixed methods service evaluation of the implementation of this care pathway. This evaluation will assess how the care pathway meets the health and care needs of service users (RFH inpatients), in terms of clinical outcome, processes of care, and NHS costs. It will also seek to assess acceptance of the pathway by members of the response team and wider hospital community. All analyses will be undertaken by the service evaluation team from UCL (Department of Applied Health Research) and St George's, University of London (Population Health Research Institute).

6.
Heart ; 2017 Aug 09.
Article in English | MEDLINE | ID: mdl-28794136

ABSTRACT

OBJECTIVE: We aimed to investigate whether preoperative serum neutrophil gelatinase-associated lipocalin (sNGALpre-op) predicted postoperative acute kidney injury (AKI) during hospitalisation and 1-year cardiovascular and all-cause mortality following adult cardiac surgery. METHODS: This study was a post hoc analysis of the Effect of Remote Ischemic Preconditioning on Clinical Outcomes in Patient Undergoing Coronary Artery Bypass Graft Surgery trial involving adult patients undergoing coronary artery bypass graft. Postoperative AKI within 72 hours was defined using the International Kidney Disease: Improving Global Outcomes classification. RESULTS: 1371 out of 1612 patients had data on sNGALpre-op. The overall 1-year cardiovascular and all-cause mortality was 5.2% (71/1371) and 7.7% (105/1371), respectively. There was an observed increase in the incidence of AKI from the first to the third tertile of sNGALpre-op (30.5%, 41.5% and 45.9%, respectively, p<0.001). There was also an increase in both cardiovascular and all-cause mortality from the first to the third tertile of sNGALpre-op, linear trend test with adjusted p=0.018 and p=0.013, respectively. The adjusted HRs for those in the second and third tertiles of sNGALpre-op compared with the first tertile were 1.60 (95% CI 0.78 to 3.25) and 2.22 (95% CI 1.13 to 4.35) for cardiovascular mortality, and 1.25 (95% CI 0.71 to 2.22) and 1.91 (95% CI 1.13 to 3.25) for all-cause mortality at 1 year. CONCLUSION: In a cohort of high-risk adult patients undergoing cardiac surgery, there was an increase in postoperative AKI and 1-year mortality from the first to the third tertile of preoperative serum NGAL. Those in the last tertile (>220 ng/L) had an estimated twofold increase risk of cardiovascular and all-cause mortality at 1 year. CLINICAL TRIAL REGISTRATION: NCT101247545; Post-results.

7.
Nephron ; 135(3): 189-195, 2017.
Article in English | MEDLINE | ID: mdl-28030868

ABSTRACT

BACKGROUND: Acute kidney injury (AKI) is often detected late, leading to worse clinical outcomes. In 2012, we pioneered an AKI-alerting system for primary care clinicians (PCCs). We retrospectively analysed the alerts and evaluated PCC satisfaction to assess the feasibility of the system. METHODS: The study used a 2-pronged approach. AKI alerts, generated by an algorithm designed by University College London Hospital biochemistry department between June 2012 and June 2014, were analysed to reveal the demographics and outcomes of each patient generating an alert. Second, a survey was sent to all PCCs assessing awareness and satisfaction with the service. Simple statistical methods were applied (mean, median, SD and interquartile range). RESULTS: One hundred forty-two alerts were generated, of which 101 were genuine. Generally, the patient demographics, AKI stratification and aetiology were in keeping with the inpatient AKI population. Forty-eight percent of cases were referred to the hospital with a median length of stay of 9.9 days. Three-month mortality was 12%. Among PCCs, there was good awareness of the system with most finding it valuable. The key complaints around the system were to do with lack of knowledge of its existence. CONCLUSIONS: Our evaluation has demonstrated that the implementation of AKI alerts in the community is technically feasible, does not result in excessive demand on hospital services, appears to influence PCC behaviour and was perceived overwhelmingly as a useful service by these clinicians. This experience should inform further developments including behavioural interventions (such as clinician alerts) to improve community AKI care.


Subject(s)
Acute Kidney Injury/diagnosis , Laboratory Critical Values , Acute Kidney Injury/mortality , Acute Kidney Injury/therapy , Adult , Aged , Aged, 80 and over , Algorithms , Automation , Community Health Services , Creatinine/blood , Female , Humans , Male , Middle Aged , Primary Health Care , Retrospective Studies , Surveys and Questionnaires , Young Adult
8.
Cardiorenal Med ; 6(3): 169-79, 2016 May.
Article in English | MEDLINE | ID: mdl-27275153

ABSTRACT

BACKGROUND: Renal impairment is a known predictor of mortality in both the general population and in patients with cardiac disease. The aim of this study was to evaluate factors that determine mortality in patients with chronic kidney disease (CKD) who have undergone percutaneous coronary intervention (PCI). METHODS: In this study we included 293 consecutive patients with CKD who underwent PCI between 1st January 2007 and 30th September 2012. The primary outcome that we studied was all-cause mortality in a follow-up period of 12-69 months (mean 38.8 ± 21.7). RESULTS: Age (p < 0.001), PCI indication (p = 0.035), CKD stage (p < 0.001) and left ventricular ejection fraction (p < 0.001) were significantly related to mortality. CKD stage 5 [hazard ratio (HR) = 6.39, 95% CI: 1.51-27.12) and severely impaired left ventricular function (HR = 4.04, 95% CI: 2.15-7.59) were the strongest predictors of mortality. Other factors tested (gender, hypertension, diabetes, hyperlipidaemia, established peripheral vascular disease/stroke, coronary arteries intervened, number of vessels treated, number of stents implanted and length of lesion treated) did not show any correlation with mortality. CONCLUSIONS: The mortality of patients with CKD undergoing PCI increases with age, worsening CKD stage and deteriorating left ventricular systolic function, and it is also higher in patients with acute coronary syndromes compared to those with stable coronary artery disease.

9.
BMC Musculoskelet Disord ; 17: 2, 2016 Jan 05.
Article in English | MEDLINE | ID: mdl-26728714

ABSTRACT

BACKGROUND: Primary Sjögren syndrome (pSS) is a common autoimmune condition which primarily affects epithelial tissue, often including the kidney causing either tubulointerstitial nephritis (TIN) or more rarely, an immune complex related glomerulonephritis. METHODS: We describe the clinical, biochemical and histological characteristics of 12 patients with pSS related TIN and their response to treatment with antiproliferative agents. All 12 patients were investigated and treated at the UCL Centre for Nephrology in London. RESULTS: All patients had TIN demonstrated via needle biopsy; immunophenotyping showed that the interstitial infiltrate was predominantly a CD4+ T-cell infiltrate. Urinary acidification testing demonstrated distal renal tubular acidosis in 8 patients. Proximal tubular dysfunction was present in 5 patients. All but 1 patient were treated with antiproliferative agents and most also with a reducing course of steroids. In the treated patients, there was a significant improvement in the serum creatinine and measured GFR. CONCLUSION: Patients with pSS TIN have significant renal impairment and other functional tubular defects. There is a mononuclear lymphocytic infiltrate on renal biopsy and this appears to be mainly a CD4+ T-cell infiltrate. Treatment with mycophenolate (and corticosteroids) improves the renal function in patients with pSS TIN.


Subject(s)
Immunosuppressive Agents/therapeutic use , Nephritis, Interstitial/diagnosis , Nephritis, Interstitial/drug therapy , Sjogren's Syndrome/diagnosis , Sjogren's Syndrome/drug therapy , Adrenal Cortex Hormones/therapeutic use , Adult , Aged , Female , Humans , Male , Middle Aged , Mycophenolic Acid/analogs & derivatives , Mycophenolic Acid/therapeutic use , Nephritis, Interstitial/complications , Sjogren's Syndrome/complications , Treatment Outcome
10.
N Engl J Med ; 373(15): 1408-17, 2015 Oct 08.
Article in English | MEDLINE | ID: mdl-26436207

ABSTRACT

BACKGROUND: Whether remote ischemic preconditioning (transient ischemia and reperfusion of the arm) can improve clinical outcomes in patients undergoing coronary-artery bypass graft (CABG) surgery is not known. We investigated this question in a randomized trial. METHODS: We conducted a multicenter, sham-controlled trial involving adults at increased surgical risk who were undergoing on-pump CABG (with or without valve surgery) with blood cardioplegia. After anesthesia induction and before surgical incision, patients were randomly assigned to remote ischemic preconditioning (four 5-minute inflations and deflations of a standard blood-pressure cuff on the upper arm) or sham conditioning (control group). Anesthetic management and perioperative care were not standardized. The combined primary end point was death from cardiovascular causes, nonfatal myocardial infarction, coronary revascularization, or stroke, assessed 12 months after randomization. RESULTS: We enrolled a total of 1612 patients (811 in the control group and 801 in the ischemic-preconditioning group) at 30 cardiac surgery centers in the United Kingdom. There was no significant difference in the cumulative incidence of the primary end point at 12 months between the patients in the remote ischemic preconditioning group and those in the control group (212 patients [26.5%] and 225 patients [27.7%], respectively; hazard ratio with ischemic preconditioning, 0.95; 95% confidence interval, 0.79 to 1.15; P=0.58). Furthermore, there were no significant between-group differences in either adverse events or the secondary end points of perioperative myocardial injury (assessed on the basis of the area under the curve for the high-sensitivity assay of serum troponin T at 72 hours), inotrope score (calculated from the maximum dose of the individual inotropic agents administered in the first 3 days after surgery), acute kidney injury, duration of stay in the intensive care unit and hospital, distance on the 6-minute walk test, and quality of life. CONCLUSIONS: Remote ischemic preconditioning did not improve clinical outcomes in patients undergoing elective on-pump CABG with or without valve surgery. (Funded by the Efficacy and Mechanism Evaluation Program [a Medical Research Council and National Institute of Health Research partnership] and the British Heart Foundation; ERICCA ClinicalTrials.gov number, NCT01247545.).


Subject(s)
Coronary Artery Bypass , Ischemic Preconditioning/methods , Postoperative Complications/prevention & control , Aged , Aged, 80 and over , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/mortality , Double-Blind Method , Elective Surgical Procedures , Female , Heart Valves/surgery , Humans , Ischemia , Ischemic Preconditioning/adverse effects , Length of Stay , Male , Middle Aged , Prospective Studies , Quality of Life , Treatment Failure , Troponin/blood , Upper Extremity/blood supply
11.
Cancer ; 121(20): 3649-58, 2015 Oct 15.
Article in English | MEDLINE | ID: mdl-26149602

ABSTRACT

BACKGROUND: Reports have demonstrated the superior activity of combining both irinotecan and oxaliplatin (FOLFOXIRI) therapy. An option for gaining similar benefits with less toxicity would be the administration of irinotecan through a hepatic artery approach. The aim of this study was to assess the response and adverse event rates for irinotecan drug-eluting beads (DEBIRI) with folinic acid, 5-fluorouracil, and oxaliplatin (FOLFOX) and bevacizumab as a first-line treatment for unresectable colorectal liver metastasis. METHODS: Patients with colorectal liver metastases were randomly assigned to modified FOLFOX (mFOLFOX) and bevacizumab or mFOLFOX6, bevacizumab, and DEBIRI (FOLFOX-DEBIRI). The primary endpoint was the response rate. The secondary endpoints were adverse events, the rate of conversion to resection, and progression-free survival. RESULTS: The intention-to-treat population comprised 70 patients: 10 patients in the pilot and then 30 patients randomly assigned to the FOLFOX-DEBIRI arm and 30 patients randomly assigned to the FOLFOX/bevacizumab arm. The 2 groups were similar with respect to the extent of liver involvement (30% vs 30%), but a greater percentage of patients in the FOLFOX-DEBIRI arm had an Eastern Cooperative Oncology Group performance status of 1 or 2 (57% vs 31%) and extrahepatic disease (56% vs 32%, P = .02). The median numbers of chemotherapy cycles were similar (10 vs 9), and there were similar rates of grade 3/4 adverse events (54% for the FOLFOX-DEBIRI group vs 46% for the FOLFOX/bevacizumab group). The overall response rate was significantly greater in the FOLFOX-DEBIRI arm versus the FOLFOX/bevacizumab arm at 2 (78% vs 54%, P = .02), 4 (95% vs 70%, P = .03), and 6 months (76% vs 60%, P = .05). There was significantly more downsizing to resection in the FOLFOX-DEBIRI arm versus the FOLFOX/bevacizumab arm (35% vs 16%, P = .05), and there was improved median progression-free survival (15.3 vs 7.6 months). CONCLUSIONS: The simultaneous administration of mFOLFOX6 (with or without bevacizumab) and DEBIRI through the hepatic artery (FOLFOX-DEBIRI) is safe and does not cause treatment delays or increase the systemic toxicity of chemotherapy. This strategy leads to improved overall response rates, improved hepatic progression-free survival, and more durable overall progression-free survival in patients downsized to resection.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Colorectal Neoplasms/drug therapy , Liver Neoplasms/drug therapy , Liver Neoplasms/secondary , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/adverse effects , Bevacizumab/administration & dosage , Bevacizumab/adverse effects , Camptothecin/administration & dosage , Camptothecin/adverse effects , Camptothecin/analogs & derivatives , Colorectal Neoplasms/pathology , Drug Delivery Systems/instrumentation , Drug Delivery Systems/methods , Fluorouracil/administration & dosage , Fluorouracil/adverse effects , Hepatic Artery/drug effects , Humans , Irinotecan , Leucovorin/administration & dosage , Leucovorin/adverse effects , Male , Middle Aged , Organoplatinum Compounds/administration & dosage , Organoplatinum Compounds/adverse effects , Treatment Outcome
13.
Obstet Med ; 7(4): 171-3, 2014 Dec.
Article in English | MEDLINE | ID: mdl-27512448

ABSTRACT

We present a case of severe peripartum hyponatraemia that occurred following a major obstetric haemorrhage causing both an ischaemic stroke and Sheehan's syndrome and outline the investigations and management strategy required.

14.
Nephron Physiol ; 122(1-2): 1-6, 2012.
Article in English | MEDLINE | ID: mdl-23434854

ABSTRACT

BACKGROUND/AIMS: Calcium homeostasis requires regulated cellular and interstitial systems interacting to modulate the activity and movement of this ion. Disruption of these systems in the kidney results in nephrocalcinosis and nephrolithiasis, important medical problems whose pathogenesis is incompletely understood. METHODS: We investigated 25 patients from 16 families with unexplained nephrocalcinosis and characteristic dental defects (amelogenesis imperfecta, gingival hyperplasia, impaired tooth eruption). To identify the causative gene, we performed genome-wide linkage analysis, exome capture, next-generation sequencing, and Sanger sequencing. RESULTS: All patients had bi-allelic FAM20A mutations segregating with the disease; 20 different mutations were identified. CONCLUSIONS: This autosomal recessive disorder, also known as enamel renal syndrome, of FAM20A causes nephrocalcinosis and amelogenesis imperfecta. We speculate that all individuals with biallelic FAM20A mutations will eventually show nephrocalcinosis.


Subject(s)
Amelogenesis Imperfecta/genetics , Dental Enamel Proteins/genetics , Genetic Predisposition to Disease/genetics , Mutation , Nephrocalcinosis/genetics , Adolescent , Adult , Amelogenesis Imperfecta/complications , Amelogenesis Imperfecta/pathology , Child , Consanguinity , Exome/genetics , Family Health , Female , Genes, Recessive/genetics , Genome-Wide Association Study , Humans , Male , Middle Aged , Nephrocalcinosis/complications , Nephrocalcinosis/pathology , Pedigree , Sequence Analysis, DNA/methods , Syndrome , Young Adult
15.
J Vasc Interv Radiol ; 21(6): 848-55, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20400333

ABSTRACT

PURPOSE: To retrospectively evaluate the performance of computed tomography (CT) angiography in the detection and localization of clinically active gastrointestinal (GI) hemorrhage of an unknown source. MATERIALS AND METHODS: Eighty-six CT angiograms were obtained in 74 patients with the clinical diagnosis of acute GI hemorrhage of an unknown source. Results of CT angiography were recorded, and the patients' electronic medical records were reviewed for documentation of subsequent interventional procedures performed within 24 hours of the reference CT angiogram to diagnose or control ongoing GI hemorrhage. Surgical, endoscopic, and final pathologic reports, if available, were reviewed. RESULTS: Twenty-two of the 86 CT angiograms (26%) were positive for active hemorrhage, with findings confirmed in 19 of the 22 cases (86%). Thirteen cases were confirmed with angiography, five cases were confirmed with surgery, and one case was confirmed with autopsy. Sixty-four of the 86 CT angiograms were negative, and 59 (92%) of the CT angiograms required no further intervention. These patients were discharged without incident. There were no cases in which CT angiography was negative and subsequent angiography within 24 hours was positive. The overall sensitivity, specificity, accuracy, and positive and negative predictive value of CT angiography in the detection of active GI hemorrhage within this study population were 79%, 95%, 91%, 86%, and 92%, respectively. CONCLUSIONS: CT angiography provides valuable information that can be used to determine the appropriateness of catheter angiography and guide mesenteric catheterization if a bleeding source is localized. The authors' experience with this study cohort supports its use before angiography in those patients with acute GI bleeding of an unknown source who are being considered for catheter-directed intervention.


Subject(s)
Angiography/methods , Gastrointestinal Hemorrhage/diagnostic imaging , Tomography, X-Ray Computed/methods , Adult , Aged , Aged, 80 and over , Female , Humans , Longitudinal Studies , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity
17.
Radiographics ; 27(4): 1055-70, 2007.
Article in English | MEDLINE | ID: mdl-17620467

ABSTRACT

Acute gastrointestinal bleeding is a common cause of hospitalization, morbidity, and mortality in the United States. The evaluation and treatment of acute gastrointestinal bleeding are complex and often require a multispecialty approach involving gastroenterologists, surgeons, internists, emergency physicians, and radiologists. The multitude of pathologic processes that can result in gastrointestinal bleeding, the length of the gastrointestinal tract, and the often intermittent nature of gastrointestinal bleeding further complicate patient evaluation. In addition, there are multiple imaging modalities and therapeutic interventions that are currently being used in the evaluation and treatment of acute gastrointestinal hemorrhage, each with its own strengths and weaknesses. Initial experience indicates that multidetector computed tomographic angiography is a promising first-line modality for the time-efficient, sensitive, and accurate diagnosis or exclusion of active gastrointestinal hemorrhage and may have a profound impact on the evaluation and subsequent treatment of patients who present with acute gastrointestinal bleeding.


Subject(s)
Angiography/methods , Gastrointestinal Hemorrhage/diagnostic imaging , Tomography, X-Ray Computed/methods , Acute Disease , Adult , Aged , Aged, 80 and over , Angiography/instrumentation , Angiography/trends , Female , Humans , Male , Middle Aged , Practice Guidelines as Topic , Practice Patterns, Physicians'/trends , Tomography, X-Ray Computed/instrumentation , Tomography, X-Ray Computed/trends
20.
Int J Biochem Cell Biol ; 37(6): 1151-61, 2005 Jun.
Article in English | MEDLINE | ID: mdl-15778079

ABSTRACT

Renal tubular acidosis is a metabolic acidosis due to impaired acid excretion by the kidney. Hyperchloraemic acidosis with a normal anion gap and normal (or near normal) glomerular filtration rate, and in the absence of diarrhoea, defines this disorder. However, systemic acidosis is not always evident and renal tubular acidosis can present with hypokalaemia, medullary nephrocalcinosis and recurrent calcium phosphate stone disease, as well as growth retardation and rickets in children, or short stature and osteomalacia in adults. Renal dysfunction in renal tubular acidosis is not always confined to acid excretion and can be part of a more generalised renal tubule defect, as in the renal Fanconi syndrome. Isolated renal tubular acidosis is more usually acquired, due to drugs, autoimmune disease, post-obstructive uropathy or any cause of medullary nephrocalcinosis. Less commonly, it is inherited and may be associated with deafness, osteopetrosis or ocular abnormalities. The clinical classification of renal tubular acidosis has been correlated with our current physiological model of how the nephron excretes acid, and this has facilitated genetic studies that have identified mutations in several genes encoding acid and base ion transporters. In vitro functional studies of these mutant proteins in cell expression systems have helped to elucidate the molecular mechanisms underlying renal tubular acidosis, which ultimately may lead to new therapeutic options in what is still treatment only by giving an oral alkali.


Subject(s)
Acidosis, Renal Tubular/physiopathology , Kidney/physiopathology , Acidosis, Renal Tubular/classification , Acidosis, Renal Tubular/genetics , Adult , Animals , Anion Exchange Protein 1, Erythrocyte/genetics , Anion Exchange Protein 1, Erythrocyte/physiology , Carbonic Anhydrase II/physiology , Child , Humans , Proton-Translocating ATPases/physiology
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