Biomedical subjects

Robert F Reilly

Publications and source records attributed to Robert F Reilly.

9 recordsLinked to original sources

PubMed2006

Hypophosphatemia: an evidence-based approach to its clinical consequences and management.

Optimal cellular function is dependent on maintenance of a normal serum phosphorus concentration. Serum phosphorus concentration is affected by several determinants, the most important of which is regulation of phosphorus reabsorption by the kidney. The majority of this reabsorption (80%) occurs in the proximal tubule and is mediated by an isoform of the sodium-phosphate cotransporter (NaPi-II). Parathyroid hormone, via a variety of intracellular signaling cascades leading to NaPi-IIa internalization and downregulation, is the main regulator of renal phosphate reabsorption. Shift of phosphorus from extracellular to intracellular compartments, decreased gastrointestinal absorption, and increased urinary losses, are the primary mechanisms of hypophosphatemia, which affects approximately 2% of hospitalized patients. Hypophosphatemia has been implicated as a cause of rhabdomyolysis, respiratory failure, hemolysis and left ventricular dysfunction. With the exception of ventilated patients, there is little evidence that moderate hypophosphatemia has significant clinical consequences in humans, and aggressive intravenous phosphate replacement is unnecessary. By contrast, patients with severe hypophosphatemia should be treated. Intravenous repletion may be considered, especially for patients who have clinical sequelae of hypophosphatemia.

Cardiomyopathies↗

PubMed2006

Long-term comparison of sevelamer hydrochloride to calcium-containing phosphate binders.

AIM: In patients with end-stage renal disease (ESRD), hyperphosphataemia and an elevated calcium-phosphorus (Ca-P) product contribute to morbidity and mortality. Suggested target goals for serum phosphorus concentration and calcium-phosphorus product have recently been lowered. As a result, long-term comparative studies of the efficacy of phosphate binders are critical. This study compares the long-term efficacy of sevelamer hydrochloride to calcium-containing binders (CCB). METHODS: A retrospective chart review was conducted in 30 patients receiving sevelamer hydrochloride for >1 years and 25 patients receiving CCB. RESULTS: Patients on sevelamer hydrochloride had lower serum bicarbonate concentration than those on CCB, 18.6 +/- 2.7 versus 20.3 +/- 1.8 mmol/L (P = 0.0017). Serum phosphorus concentration was higher in patients on sevelamer hydrochloride compared to CCB 2.10 +/- 0.87 versus 1.74 +/- 0.28 mmol/L (P = 0.0013), as was the Ca-P product 4.97 +/- 0.94 mmol2L2 (62.1 +/- 11.8 mg2/dL2) versus 3.97 +/- 1.18 mmol2/L2 (49.7 +/- 14.7 mg2/dL2), P = 0.0009). Only 36% of patients on sevelamer hydrochloride compared with 68% on CCB (P = 0.015) met the serum phosphorus goal of < or =1.78 mmol/L. CONCLUSION: Patients on sevelamer hydrochloride for >1 years compared to those on CCB had a lower serum bicarbonate concentration, a higher serum phosphorus concentration and a higher Ca-P product. Clinicians should balance the increase in calcium load with CCB versus the cost and effectiveness of sevelamer hydrochloride in choosing a phosphate binder for ESRD patients.

Acetates↗

PubMed2005

Retroperitoneal fibrosis presenting as acute renal failure.

BACKGROUND: A 60-year-old man with a history of atherosclerotic disease of the carotid and coronary vasculature presented with lower back pain and acute renal failure. Imaging studies revealed bilateral ureteral obstruction by a large retroperitoneal mass. INVESTIGATIONS: Physical examination, urine and blood analysis, catheterization, radiography of the chest, abdominal and pelvic CT, magnetic resonance angiography, renal ultrasound and biopsy of mass. DIAGNOSIS: Retroperitoneal fibrosis. MANAGEMENT: Ureteral stenting, laparoscopic ureterolysis, and immunosuppressive therapy with prednisone and mycophenolate mofetil.

Acute Kidney Injury↗

PubMed2005

Effect of intravenous iron on haemodialysis catheter microbial colonization and blood-borne infection.

BACKGROUND: Intravenous (i.v.) iron is employed to treat absolute and relative iron deficiency in end-stage renal disease patients. However, there exists the possibility that i.v. iron increases infection risk. This pilot study examines whether i.v. iron gluconate acutely increases tunnelled haemodialysis catheter colonization, microbial growth, or blood-borne infection. METHODS: Nineteen patients with haemodialysis catheters who met criteria to receive an i.v. iron load entered the study. Six matched patients with catheters who did not receive iron were controls. Blood aspirated from the catheter prior to initiation of haemodialysis was sent for qualitative/quantitative cultures. The study consisted of three baseline cultures, five cultures during iron (125 mg of ferric gluconate per treatment), and three cultures following iron administration. Patients were monitored for infection for 30 days following iron. RESULTS: Fifteen iron-treated patients and six controls completed the study. Thirty-three per cent of treated patients were colonized at baseline; 66% were colonized following iron. Thirty-three per cent of controls (2/6) were colonized at baseline; no new colonization developed during follow up. Neither treated patients nor controls had significant microbial growth within catheters; one patient in the iron-treated group developed candidaemia. CONCLUSION: Intravenous iron is not associated with acute microbial growth in catheters or clinical infection. However, a trend towards increased catheter colonization following iron administration exists.

Adult↗

PubMed2003

Vascular access surveillance: evaluation of combining dynamic venous pressure and vascular access blood flow measurements.

BACKGROUND/AIMS: Vascular access thrombosis is one of the most morbid problems encountered by hemodialysis patients. Surveillance protocols utilizing venous pressure (Vp) and vascular access blood flow (VABF) measurements have been employed to preserve vascular access. We undertook a study to evaluate combined dynamic Vp and VABF measurements in the identification of vascular access impairment. We also assessed the effect of preventive repair on thrombosis rates in impaired vascular accesses identified by surveillance. METHODS: Eighty-six chronic hemodialysis patients with a functioning vascular access were enrolled into the surveillance protocol. All vascular accesses with greater than 50% of monthly Vp readings >120 mm Hg or VABF <500 ml/min in arteriovenous fistulas (AVFs) and VABF <650 ml/min in arteriovenous grafts (AVGs), or a decrease in VABF >25% compared to the highest previously measured value, were considered positive. Stenosis >50% on fistulography or a thrombotic event were defined as a 'vascular access impairment episode' while a stenosis <50% or the absence of a thrombotic event was defined as 'no vascular access impairment episode'. Thrombosis rates and intervention rates were calculated per access year at risk. RESULTS: The sensitivity and specificity of the combined surveillance protocol for AVFs were 73.3 and 91%, respectively. In AVGs, they were 68.8 and 87.5%, respectively. The rate of thrombotic events was lower in patients who underwent early repair. The addition of dynamic Vp did not reduce the thrombosis rate any further than surveillance based on VABF alone. CONCLUSION: Combined monitoring for surveillance of AVFs improved sensitivity but had little benefit in AVGs over VABF monitoring alone. Raising VABF cutoff levels might increase and improve identification of vascular access risk for thrombosis, but at the expense of lower specificity.

Arteriovenous Shunt, Surgical↗

PubMed2002

Chronic kidney disease: a new approach to an old problem.

Chronic kidney disease (CKD) is a growing health problem in the United States. Recognition of this chronic condition is crucial to facilitate the employment of measures that can slow progression to end-stage renal disease and reduce associated disease states. Furthermore, a system to classify stages of CKD is worthwhile to permit a logical approach to therapy in these patients. We herein review and summarize clinical practice guidelines put forward by the National Kidney Foundation Working Group to aid physicians in the diagnosis and management of CKD.

Adult↗

PubMedDate not supplied

The pathophysiology of immune-mediated heparin-induced thrombocytopenia.

Heparin-induced thrombocytopenia (HIT) is an important side effect of heparin therapy associated with significant morbidity and mortality if unrecognized. The platelet count typically falls below 150,000/ micro l 5-14 days after heparin is started. Thrombosis is the major clinical complication. The diagnosis is confirmed with a variety of functional and antigenic assays. Heparin binds to PF4, resulting in a conformational change in the molecule that exposes neo-epitopes that act as immunogens. Antibodies form against the heparin-PF4 complex, the major target antigen. The IgG-heparin-PF4 immune complex binds either via its Fab domain to the platelet surface or via its Fc domain to the FcgammaIIA receptor on the surface of the platelet, resulting in further platelet activation. Continued release of PF4 from activated platelets leads to increasing PF4-heparin complex formation, and a self-propagating cycle of platelet consumption and generation of procoagulant platelet-derived microparticles. Other procoagulant effects of the HIT antibody include endothelial cell damage, stimulation of platelet-leukocyte aggregates, and release of tissue factor from monocytes.

Anticoagulants↗

PubMedDate not supplied

Nephrogenic fibrosing dermopathy: an unusual skin condition associated with kidney disease.

We report the case of a patient who, while on long-term hemodialysis (HD), developed nephrogenic fibrosing dermopathy, a newly described sclerosing skin disorder. This disorder is characterized by thickened, hardened skin with brawny hyperpigmentation and raised plaques. The most common patient complaints are pruritus and dysesthesia. The extremities are predominantly involved with sparing of the torso and face. Dysfunction of internal organs has not been described, distinguishing it from other fibrosing conditions such as scleroderma. The skin biopsy is characterized by haphazardly arranged dermal collagen spindle cells in the reticular dermis. Extensive mucin deposits are interposed between collagen bundles and there are an increased number of fibroblast-type cells. In contrast to scleroderma, inflammatory cells are generally absent. Corticosteroid therapy can be tried, but in our patient was of no benefit.

Fibrosis↗

PubMedDate not supplied

Anticoagulation and continuous renal replacement therapy.

More than half of patients with acute renal failure in the intensive care unit require dialysis, and the majority of them have significant hemodynamic instability. Continuous renal replacement therapy (CRRT) is often the preferred dialysis modality in these patients. One requirement for CRRT is anticoagulation, which can expose patients to the risk of bleeding. However, absence of effective anticoagulation may result in clotting of the CRRT circuit and subsequently less effective treatment. While heparins are widely used for anticoagulation, because of potential side effects such as bleeding and heparin-induced thrombocytopenia, alternative anticoagulation protocols should be considered. Citrate anticoagulation, regional heparin/protamine, predilution, r-hirudin, prostacyclin, and nafamostat are among these methods.

Acute Kidney Injury↗