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Andrew Davenport

Publications and source records attributed to Andrew Davenport.

At least 19 recordsLinked to original sources
PubMed2006

Cognitive functioning pre- to post-kidney transplantation--a prospective study.

BACKGROUND: Kidney transplantation (TX) may ameliorate the neuropsychological (NP) impairments in end-stage renal disease (ESRD). Previous studies have suffered from small sample sizes, lack of standardization of dialysis adequacy, and insufficiently sensitive NP tests. METHODS: Twenty-eight medically stable patients aged 44.04 (12.01) years with ESRD were investigated before and at 6 months after successful kidney TX using an NP test battery, which assessed attention-concentration, psychomotor ability and memory. Formal kinetic modelling of dialysis delivery ensured adequate renal replacement therapy. Transplant function was good on stable doses of immunosuppressive medication, without evidence of rejection at the time of testing. RESULTS: Within-subject comparisons showed statistically significant improvement in memory performance after kidney TX. Other NP measures (attention-concentration and psychomotor abilities) showed non-significant improvements. Normative comparisons showed NP impairments on dialysis, which were not apparent after TX. CONCLUSION: These data demonstrate improvements in cognition following kidney TX and emphasize the reversibility of the memory problems evidenced in dialysis.

Adult↗
PubMed2006

Audit of the effect of dialysate sodium concentration on inter-dialytic weight gains and blood pressure control in chronic haemodialysis patients.

BACKGROUND/AIMS: Over the last three decades the standard dialysate sodium concentration has increased from 136 to 140 mmol/l (mEq/l) today. There has been great debate as to whether a reduction in dialysate sodium alone can lead to improved blood pressure control, and reduced inter-dialytic weight gain. METHODS: An audit was performed in 469 maintenance regular haemodialysis patients who dialysed in seven different centres under the care of one university medical school. RESULTS: Those centres which predominantly used a dialysate sodium of 140 mmol/l (mEq/l) had increased inter-dialytic weight gains, with more difficult blood pressure control, as not only did a greater percentage of patients require anti-hypertensive medication, but also more were prescribed multiple classes of anti-hypertensive agents. There was no difference in the frequency of symptomatic intra-dialytic hypotension. CONCLUSIONS: A reduction in dialysate sodium was associated with lower inter-dialytic weight gains, without any additional intra-dialytic hypotensive episodes. Those patients in whom the difference between the time-averaged dialysate sodium concentration and the midweek pre-dialysis serum sodium was positive result had increased inter-dialytic weight gains, compared to those with a negative value. Reduced dialysate sodium alone was not effective in controlling blood pressure without additional proper dietary sodium restriction.

Adult↗
PubMed2006

Ascites due to right atrial myxoma in a haemodialysis patient.

BACKGROUND: Persistent fluid overload in patients on renal replacement therapy despite good dialysis adequacy or obvious cardiac dysfunction should prompt a search for rarer causes. CASE PRESENTATION: We report here a rare cause of persistent peripheral oedema and ascites in a well-dialysed patient. CT scanning revealed a right atrial myxoma that was later confirmed on an echocardiogram. CONCLUSION: Fluid overload states are common in patients on dialysis. Common causes are inadequacy of dialysis and non-compliance. Where aetiology is not easily apparent further investigations into rarer causes should be sought.

Aged↗
PubMed2006

Profound pseudohypocalcemia due to gadolinium (Magnevist) contrast in a hemodialysis patient.

We report the first case of profound "pseudohypocalcemia" after the administration of the gadolinium-based contrast media dimeglumine gadopentate (Magnevist; Schering Diagnostics AG, Berlin, Germany) to a long-standing hemodialysis patient. Initial calcium measurements were made by using our routine laboratory colorimetric method based on o-Cresolphthalein (Roche Modular-P; Roche Diagnostics Ltd, Lewes, Sussex, UK). Because the patient was well, with no signs of hypocalcemia, retrospective testing using both another o-Cresolphthalein colorimetric method (Roche Integra 800) and measurement of ionized calcium with an ion-selective electrode were performed, and confirmed laboratory pseudohypocalcemia.

Contrast Media↗
PubMed2006

Intradialytic complications during hemodialysis.

With the advent of developments and advances in hemodialysis machine technology, dialysate water purification, and dialyzers, the clinical spectrum of intradialytic complications has changed over the decades. In the pioneering days of hemodialysis, patients could develop allergic reactions to dialyzer membranes, sterilizing and reprocessing agents, coupled with machines that could not accurately control ultrafiltration rates, and chemically and bacterially contaminated dialysate. Whereas today, although cardiovascular problems remain the most common intradialytic complication, these are mainly due to the time restraints of trying to cope with excessive dialytic weight gains and achieve target dry weight on a thrice weekly schedule, coupled with an aging elderly dialysis population with increasing co-morbidity.

Anaphylaxis↗
PubMed2006

Heparin-induced thrombocytopenia: an uncommon but serious complication of heparin use in renal replacement therapy.

Heparin-induced thrombocytopenia (HIT) is an uncommon but potentially life-threatening complication of heparin therapy. Hemodialysis and hemofiltration patients are regularly exposed to heparin, which is used for extracorporeal anticoagulation. Type II HIT (HIT-II) is the rarer immune-mediated form and is of huge clinical significance. The clinical manifestation of HIT-II is characteristically with venous and arterial thrombotic events. However, systemic and pulmonary reactions have been reported. Type II HIT is due to antibodies to the heparin-platelet factor 4 complex, which induce a cascade of events leading to thrombocytopenia and thrombosis. Nowadays, with increasing availability of functional and immunoassay tests for HIT-associated antibodies, HIT diagnosis can be confirmed more readily. Hence, it is important to rapidly recognize, diagnose, and manage this syndrome early in hemodialysis patients with thrombocytopenia to avoid serious consequences resulting in morbidity and mortality. We report a case of HIT-II manifesting atypically as a "pseudopulmonary embolus" in a hemodialysis patient and discuss the clinical management of HIT.

Aged↗
PubMed2006

Changing patterns of pericardial disease in patients with end-stage renal disease.

Pericarditis can occur in patients with chronic renal failure before initiation of dialysis. It is also described in established dialysis patients. Traditionally, the cause of pericarditis in such settings has been attributed to uremia and/or inadequate dialysis and it is consequently thought that intensifying the dialysis process in such patients could improve outcome. We report here 7 cases of acute pericarditis in patients with end-stage renal disease on renal replacement therapy. Only 3 of the patients gave any history of chest pain, and a pericardial friction rub was only noted in 2. Despite a period of intensive dialysis, none of the patients improved and all required pericardial drainage as the definitive curative procedure. The clinical presentation of acute pericarditis in dialysis patients therefore may be atypical and pericardial drainage should be considered early, as intensive dialysis alone may not lead to resolution.

Acute Disease↗
PubMed2005

Renal replacement therapy and the kidney: minimizing the impact of renal replacement therapy on recovery of acute renal failure.

PURPOSE OF REVIEW: Although renal replacement therapy is the mainstay of supportive care in patients with severe acute renal failure, its performance can have untoward effects that contribute to the prolongation of renal failure or impede the ultimate recovery of renal function. In this review, we categorize the major complications associated with renal replacement therapy and assess their impact on recovery of renal function. RECENT FINDINGS: The major mechanisms by which renal replacement therapy is postulated to delay renal recovery include treatment-associated hemodynamic instability, vascular catheter-related bacteremia and sepsis, and cytokine activation by bioincompatible membranes. Clinical data regarding the role of dialysis catheter infections in delay of renal recovery are lacking. The data regarding the role of membrane biocompatibility and the modality and dose of renal replacement therapy are limited and conflicting. SUMMARY: Clinical recommendations must be limited to the broad admonishment that complications during renal replacement therapy, including hemodynamic instability and catheter-related bacteremia, be minimized by using best clinical practices, while recognizing that the impact of specific practices on recovery of renal function have not been evaluated. The data do not support recommendations regarding utilization of specific membranes or the modality or dose of renal replacement therapy on the basis of their impact on recovery of renal function.

Acute Kidney Injury↗
PubMed2004

Neuropsychological performance after kidney transplantation: a comparison between transplant types and in relation to dialysis and normative data.

BACKGROUND: Neuropsychological (NP) performance after kidney transplantation (TX) has received little attention. This study compared NP functioning between dialysis and transplant patients and between living-related donor (LRD) and cadaver (CAD) transplant recipients. The association between immunosuppressive medication and NP outcomes was also examined. METHODS: One hundred and seventeen transplant recipients (25 LRD and 92 CAD patients) and 145 dialysis patients (77 haemodialysis and 68 peritoneal dialysis) were administered an NP test battery to assess learning and verbal recall, attention and concentration, and psychomotor abilities/speed. Biochemical markers of renal function were also assessed. RESULTS: Overall, transplant patients showed normal cognitive functioning in all domains assessed. NP performance was found to be equivalent in both transplant groups and in patients on cyclosporin and those on tacrolimus. ANCOVAs showed that TX patients performed significantly better than dialysis patients on selective NP tests, i.e. the two memory tasks and two out of the four tests of attention. No differences were found in motor tasks. CONCLUSIONS: Our results reveal no evidence of NP deficits in TX patients. The NP advantage of TX relative to dialysis is evident mainly in verbal memory.

Adult↗
PubMed2004

Intraperitoneal nitric oxide production in patients treated by continuous ambulatory peritonal dialysis.

BACKGROUND: Nitric oxide (NO) generation within the peritoneum could potentially affect peritoneal transport by increasing capillary vasodilatation, and increase peritoneal permeability during episodes of bacterial peritonitis. As peritoneal mesothelial cells have a common embryological derivation with endothelial cells, then mesothelial cells could potentially be a major source of locally produced NO. METHODS: NO was measured using the Griess reaction in fresh and spent dialysate effluent (SPDE) from uninfected CAPD patients, and from those during episodes of bacterial peritonitis. Human peritoneal mesothelial cells (HPMC) were cultured and NO production determined in the presence of SPDE and the effect of a potential NO substrate, L-arginine, and NO synthase inhibitor, L-NMMA. NO production by peritoneal macrophages (MØ), obtained from SPDE and the effect of staphylococci was also determined. RNA for inducible nitric oxide synthase (iNOS) was sought using Northern blotting technique following combination stimulation with lipopolysaccharide and cytokines (IL-1beta, TNF-alpha and gamma-INF, and/or spent dialysate from patients with bacterial peritonitis). RESULTS: Whereas fresh CAPD dialysate was nitrite-free, SPDE from the day time exchange contained 41 +/- 3 microM (nitrite and nitrate), and that from the overnight dwell 91 +/- 8 microM. During CAPD peritonitis, dialysate nitrite and nitrate increased from 9.3 +/-0.8 to 17.5 +/- 2.4 microM/l x h, for the first CAPD bag at presentation, and 15.2 +/- 1.8 for the second and 16.2 +/- 2.4 for the third exchange (p < 0.01 compared to non-infected control). By the second day, levels had returned to baseline, 7.3 +/- 0.9 microM/l x h. HPMC produced 261 nmol nitrate and nitrite/mg cell protein, and this increased in a dose-dependent manner with the addition of spent uninfected CAPD dialysate, to 365 nmol/mg with 1:10 dilution and 655 nmol/mg with 1:2 dilution, p < 0.001. The addition of the substrate, L-arginine, resulted in a 10% increase in nitrite and nitrate production, whereas the addition of L-NMMA produced a 10% reduction. Peritoneal MØ obtained from SPDE produced similar quantities of nitrite and nitrate to peritoneal mesothelial cells, and cultures of Staphylococcus aureus resulted in a reduction in nitrite and nitrate levels, as they were used as a growth requirement. However, we could not demonstrate RNA production for iNOS by HPMC following cytokine or SPDE stimulation. CONCLUSIONS: This suggests that HPMC may be an important source of locally generated NO within the peritoneal cavity under basal conditions, but as they do not contain iNOS, the increased NO produced during episodes of acute bacterial peritonitis is more likely due to a combination of increased NO production by peritoneal endothelial cells and transmigrating macrophages.

Arginine↗