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S Di Filippo

Publications and source records attributed to S Di Filippo.

At least 91 records · Page 5Linked to original sources
PubMed1984

Sodium kinetics across dialysis membranes.

The kinetics of sodium across dialysis membranes were studied during diffusion and during convection utilizing cuprophan and cellulose hydrate membranes. During diffusion the changes in plasma water sodium concentration are correlated to the sodium concentration gradient between plasma water and dialysate but an increase also occurs when the gradient is annulled, due to the Donnan effect. During convection the plasma water sodium concentration increases during the passage through the dialyzer and the ultrafiltrate sodium concentration is significantly lower than the plasma water sodium concentration; this is due to the fact that the plasma proteins, as anions unable to cross the membrane, affect the kinetics of the sodium cations. Therefore, during diffusion the kinetics of sodium are mainly affected by the sodium concentration gradient and by the plasma protein concentration, while during convection the plasma protein concentration is the main factor affecting the kinetics of sodium.

Body Water↗
PubMed1984

Specific local immunotherapy in the treatment of hay fever.

The authors refer results of a 3-year study carried out on ten patients suffering from hay fever, diagnosed by means of skin tests, specific nasal provocation and serum RAST who underwent specific local immunotherapy consisting of application of an aqueous allergenic extract, the initial level of which was based on threshold values resulting from the nasal provocation test. The two-monthly check ups were based on the evaluation of mucociliary clearance, anterior rhinorheomanometry, specific nasal provocation and the test of Maunsell for blocking antibodies, as well as on the drawing up of a daily symptomatological diary for each single patient. The results were extremely interesting: subsidence of symptoms during the pollinating season, an increase in the number of blocking serum antibodies and of threshold values relative to specific nasal provocation. Conductance and mucociliary clearance, which were both decidedly pathological before beginning the local immunotherapy, slowly returned to the norm. The authors, furthermore, refer that the use of disodium cromoglycate during the first months of specific local immunotherapy which allows them to reach doses 5-7 times greater than those obtainable with the above mentioned form of treatment, offers uncertain advantages as far as local and above all general immunity is concerned and this alone does not justify the use of nasal applications in the treatment of bronchial asthma of allergic origin.

Adolescent↗
PubMed1982

"Physiological" and "pharmacological" dialysate sodium concentrations.

Forty three uremic patients on regular hemodialysis treatment (4 hours 3 times/week) were dialyzed for a period of 28.95 +/- 14.46 months with a dialysate sodium concentration (NaD) of 142 mEq/l, similar to their plasma water sodium concentration corrected for the Donnan factor ("physiological" NaD). Blood pressure (BP) and body weight (BW) dropped significantly. During two following periods, lasting 18 and 14 months, with NaD 148 mEq/l, similar to the patients' plasma water sodium concentration ("pharmacologically high" NaD), cardiovascular stability improved and BP did not show significant increase. Using "physiological" and "pharmacologically high" NaD the removal of water and sodium by convection improves the cardiovascular stability and the patients' well being, without bringing about the feared long-term cardiovascular side effects, if an appropriate dry body weight is achieved, because of better correction of the cellular overhydration.

Blood Pressure↗
PubMed1981

Long-term haemodialysis treatment with sodium removal by convection.

Forty-three uraemic patients were studied for 60.95 +/- 14.46 months of haemodialytic treatment (4 hours, 3 times/week). After a first dialysis period of 28.95 +/- 14.46 months with a dialysate sodium concentration (NaD) of 142 mEq/L blood pressure (BP) and body weight (BW) showed values significantly lower (p less than 0.001). During a following period of 32 months with NaD 148mEq/L BP did not show significant changes. A more 'physiological' removal of water and sodium by convection does not bring about the feared long term cardiovascular side effects if an appropriate dry BW is achieved, probably because of better correction of the cellular overhydration.

Adult↗
PubMed1980

Steroid pulses and plasmapheresis in the treatment of acute renal failure in multiple myeloma.

Four patients with acute renal failure due to myeloma (IgG with lambda, lambda, lambda, IgG with kappa) were studied; serum creatinine was 4.7, 5.9, 4.25, 10.8 mg%, and proteinuria 2.1, 2.8, 5.2, 4.2g/24h respectively. Renal biopsy specimens (3 patients) showed interstitial fibrosis, oedema, infiltration of mononuclear cells, tubular atrophy or dilatation with many 'myeloma kidney' casts. The patients were treated with plasmapheresis (2-4 exchanges) and methylprednisolone pulses (three to four 1g pulses). Maintenance therapy included prednisone, vincristine, melphalan and cyclophosphamide. After a follow up of 26, 17, 8, 6 months respectively, serum creatinine levels are 1.7, 2.4, 1.8, 4.2mg% respectively. Proteinuria disappeared after three months of therapy in 3 patients, and then remained absent for the successive follow up.

Acute Kidney Injury↗
PubMed1978

Ultrafiltration and high sodium concentration dialysis: pathophysiological correlation.

Five stabilised uraemic patients underwent two different procedures using the Gambro Ultradiffuser: ultrafiltration alone for one hour (mean body weight loss 2.97 +/- 0.24 kg) and ultrafiltration with simultaneous dialysis for one hour (mean body weight loss 2.92 +/- 0.22 kg) using a given dialysate sodium concentration which reproduced the changes in osmolality which occur during ultrafiltration alone. This mean sodium concentration was 154.75 +/- 2.02 mEq/L. The results did not show significant differences for the two procedures as regards tolerance to dehydration. These results underline the key role of osmolar stability in making dehydration tolerable.

Blood Pressure↗
PubMedDate not supplied

Changes in the clinical condition of haemodialysis patients.

The characteristics of the dialytic population have substantially changed over the past 30 years, becoming older and with a greater number of coexisting diseases. The considerable evolution in treatment modalities has lead to a significant increase in the efficacy and tolerability of dialysis. However, physicians have to deal with illnesses in long term dialysis survivors that may be a consequence of inadequate renal replacement therapy rather than of the dialysis procedure per se. Cardiovascular diseases are the leading cause of death and, although many of the risk factors are the same as in the general population (i.e. hypertension), some appear to be specific to CRF (i.e. hyperparathyroidism, anaemia). Age is the most important demographic factor associated with increased mortality. The increasing incidence of ESRD diabetic patients, as well as malnutrition, also contribute to higher mortality in RRT. The therapeutic answer to a worsening in clinical condition is adequate medical care (starting in the conservative phase), with particular attention being given to correcting anaemia, hypertension, volume overload and hyperparathyroidism, and preventing malnutrition. Treatment modalities also play a crucial role. Data suggest that adequate dialytic dose (and possibly time) can reduce morbidity and mortality, and on-line sodium and potassium modelling can improve intradialytic cardiovascular stability and reduce arrhythmias. Long-term treatment with synthetic high-flux membranes may confer some beneficial effect on beta2-m amyloidosis-related morbidity and may also reduce mortality. Family and social support greatly affect the quality of life of the patients. However technologically advanced, no procedure can succeed unless it is performed in the context of humanised health care directed towards patient needs.

Age Factors↗
PubMedDate not supplied

Effect of sodium pool changes on blood pressure in patients undergoing PFD: design of a prospective randomized multicenter trial.

Blood pressure control is important during dialysis and the interdialytic period because of the frequency and potential seriousness of hypotension and hypertension. Water and sodium removal play an important role in the genesis of intradialytic cardiovascular instability or hypertension. Changing dialysate sodium concentrations without the aid of a kinetic model can sometimes give good results but is only an empirical approach. Therefore, this clinical trial was designed to prospectively investigate the advantages of changes in the sodium pool on the blood pressure profile of patients undergoing paired filtration dialysis (PFD). The hypothesis to be tested is whether using a dialysate conductivity which, according to the conductivity kinetic model, ensures that the conductivity of the ultrafiltrate at the end of each dialysis session is 0.3 mS/cm more (B) or less (C) than the mean during the run-in period, improves blood pressure control either in patients prone to intradialytic hypotension or patients who are hypertensive or normotensive with antihypertensive treatment. Patients will be randomly allocated to one of two treatment sequences (where treatment A is standard PFD): AABB or ABAA for patients with intradialytic hypotension; AACC or ACAA for hypertensive patients. During the experimental phase arterial blood pressure will be measured and symptoms reported by the patients will be recorded.

Blood Pressure↗
PubMedDate not supplied

[Anti-blastic hyperthermic perfusion in the treatment of melanoma of the extremities in the loco-regional diffusion phase].

Primary limb melanoma may recur in terms of satellitosis, in transit metastases and/or regional node involvement. Hyperthermic antiblastic perfusion (HAP) permits the isolation of involved extremity from the systemic circulation and to deliver high doses of antineoplastic drugs. The association of cytostatic drugs to hyperthermia (> or = 41.5 degrees C) results in a synergistic effect with an increased therapeutic effectiveness. The overall 5 and 10-year survival rates in relation to the disease stages are st. II 75% and 67%; st. IIIA 59% and 42%; st. IIIAB 36% and 30% respectively. The results confirm that HAP is considered the treatment of choice of loco-regional spreading limb melanoma. Recently, the tumor necrosis factor (TNF) has been combined with Melphalan and hyperthermia. This trimodality association seems to be superior to Melphalan and hyperthermia alone only in patient with bulky tumors (i.e., multiple nodules), as a matter of fact the complete tumor response rates observed in these patients have been 67% and 20% respectively. The greater effectiveness of trimodality association has to be confirmed by multicentric randomized trials.

Antineoplastic Agents, Alkylating↗
PubMedDate not supplied

[Guidelines for dialysis. Replacement therapy for acute renal failure in critically ill patients].

Acute renal failure (ARF) in patients admitted to the intensive care unit (ICU) is mostly caused by ischemic or toxic injury, with a higher incidence in the latest years due to the growing number of interventions in cardiac and vascular surgery and to the general enhancement of reanimation techniques, which allow a better outcome among ICU patients. In critically ill patients, the ARF incidence reported in the literature ranges between 1 and 25%. Among ICU patients with ARF the mortality is between 40 and 65%, much more than in patients without this complication. Higher mortality rates, longer hospitalisation times and higher therapy costs demand from us an early diagnosis and treatment of ARF. Due to the lack of controlled and randomized proofs, recommended criteria for starting renal replacement therapy (RRT) in critical ARF patients might overlap with those for ESRD therapy. Moreover, randomised and controlled trials, confirming the actual efficacy of early onset of RRT on the mortality rate, are not yet available. As for stable ESRD patients, a direct relationship between dialytic doses and mortality and morbidity has been established for ARF patients. For ARF patients, as well as for ESRD patients, a minimum Kt/V of 1.2 three times a week should be ensured, although higher doses for critical ARF patients may achieve better results. The choice between intermittent (IRRT) and continuous renal replacement therapy (CRRT) in these patients is still a controversial issue. In spite of the fact that most studies report a better outcome in patients treated with CRRT, a recent meta-analysis failed to demonstrate any difference on the relative risk (RR) of mortality and on the rate of renal recovery between patients treated with either IRRT or CRRT. Furthermore, the use of peritoneal dialysis for the treatment of ARF patients in ICU has not been dismissed yet; so far this is indeed considered to be the technique of choice in some specific clinical situations. The intrinsic urgency of dialysis in ARF patients entails the use of temporary central venous catheters. The internal right jugular vein is usually preferred for these catheters because of the easier insertion and the lower risk of stenosis and thrombosis. The anticoagulant procedure should be chosen on the basis of patient characteristics, treatment typology and the likelihood of effectively monitoring its action. The choice of buffers in the dialysate, mostly lactate or bicarbonate, should depend on patient characteristics; so far, however, controlled but not randomized studies do not show any significant difference in the correction of metabolic acidosis between lactate and bicarbonate.

Acute Kidney Injury↗
PubMedDate not supplied

[Urea distribution volume and ionic dialysance].

PURPOSE: Direct dialysis quantification (DDQ) represents the gold standard for determining urea distribution volume (V) in hemodialysis (HD) patients, but is impractical for routine use because it requires equilibrated post-dialysis plasma water urea concentration. The "formal" single-pool, variable volume, urea kinetic model (SPVV-UKM) is easier to use, needing a blood sample drawn immediately after the dialytic session, but to obtain a V value consistent with the DDQ method, it requires a correct estimate of dialyzer urea clearance (Kd), actually often overestimated. Ionic dialysance (ID) accurately estimates the "effective" urea clearance (Keff), namely Kd corrected for total recirculation. Using ID as an input parameter to SPVV-UKM, correct V values are expected when end-dialysis plasma water urea concentrations are determined in a blood sample drawn after the blood pump speed has been reduced to 50 ml/min for 2 min (Upwt2'). OBJECTIVE: We aimed to compare the V values determined by SPVV-UKM, ID and Upwt2' (VID), those determined by "formal" SPVV-UKM (VKd) and those determined by the anthropometric method proposed by Watson (VA), with the V values determined by the gold standard DDQ method (VDDQ). METHODS: Thirty-one anuric patients on chronic thrice-weekly HD were studied in 31 dialysis sessions (one per patient). RESULTS: VDDQ = 26.5 +/- 5.3 L; VID = 26.2 +/- 5.1 L; VKd = 32.1 +/- 5.7 L;. VA = 33.2 +/- 5.8 L. The mean (VID - VDDQ) difference was -0.2 +/- 1.3 L, not statistically significant (95% confidence interval (95% CI) -0.7 to 0.2 L; p=0.302); the mean (VKd - VDDQ) difference was 5.6 +/- 2.3 L, statistically significant (95% CI 4.7 to 6.4 L; p<0.001); the mean (VA - VDDQ) difference was 6.7 +/- 2.7 L, statistically significant (95% CI 5.7 to 7.7 L; p<0.001). CONCLUSIONS: ID use as an input parameter to SPVV-UKM allows adequate V determinations and, at the same time, circumvents the problem of delayed post-dialysis blood samples. On the other hand, the use of "formal" SPVV-UKM or of anthropometric equations leads to a significant overestimation in urea distribution volume.

Anuria↗
PubMedDate not supplied

[Ionic dialysance: which relationship with effective urea clearance?].

PURPOSE: It has been suggested that ionic dialysance (ID) can adequately estimate the "effective" urea clearance (eK), i.e. urea clearance corrected for total (access and cardiopulmonary) recirculation. Unfortunately, the results obtained by different authors in determining the relationship existing in vivo between ID and eK do not always agree. Furthermore, it has been recently evidenced that ID values could be different, according to the different methods used to modify the inlet dialysate conductivity during ID measurement. OBJECTIVE: We aimed to verify the relationship between the mean values of repeated instantaneous ID determinations and the urea clearance values corrected for access recirculation, urea clearance corrected for total recirculation (eK) and urea clearance corrected for both total recirculation and post-dialysis urea rebound (body urea clearance), determined according to the direct quantification method (dKDDQ, eKDDQ and bK, respectively). METHODS: Thirty-one anuric patients on chronic thrice-weekly hemodialysis (HD) were studied in 31 dialysis sessions (one per patient), performed using Integra machines equipped with the Diascan module for the automatic ID determination and the Quantiscan module for the fractional collection of outlet dialysate. The mean values of repeated ID determinations at 30 min intervals throughout each dialytic session by the Diascan module were compared with dKDDQ, eKDDQ and bK values. RESULTS: ID = 179 +/- 24 mL/min; dKDDQ = 200 +/- 27 mL/min; eKDDQ = 188 +/- 26 mL/min; bK = 165 +/- 25 mL/min. The mean (ID - dKDDQ) difference was -21 +/- 10 mL/min (95% confidence interval (95% CI) -25 to -17 mL/min; p<0.001). The mean ID/dKDDQ ratio was 0.90 +/- 0.05, indicating a mean difference between dKDDQ and ID of 10%. The mean (ID - eKDDQ) difference was -9 +/- 9 mL/min (95% CI -12 to -6 mL/min; p<0.001). The mean ID/eKDDQ ratio was 0.96 +/- 0.05; therefore, indicating a mean difference between eKDDQ and ID of only 4%. The mean (ID - bK) difference was 15 +/- 7 mL/min (95% CI 13 to 17 mL/min; p<0.001). The mean ID/bK ratio was 1.09 +/- 0.05, indicating a mean difference between bK and ID of 9%. CONCLUSIONS: The mean value of repeated ID determinations could be considered clinically as an adequate estimate of urea clearance corrected for total recirculation (eKDDQ). Given that ID determination does not require either blood sampling or laboratory tests, therefore, it becomes possible to estimate easily and rapidly, once the urea distribution volume (V) has been correctly determined, the Kt/Vsp at each dialytic session.

Anuria↗
PubMedDate not supplied

[Use of dialysate conductivity to obtain neutral sodium balance in chronic hemodialysis patients].

In order to assure a zero sodium balance in hemodialysis patients, attaining 'constant' values of total body water and plasma water sodium concentration at the end of each dialysis session is a basic pre-requisite. This is achieved by matching the ultrafiltration to the inter-dialytic weight gain and by individualizing dialysate sodium concentration at each dialysis session by making use of a kinetic model. Clinical results suggest that the single pool variable volume sodium kinetic model allows the targeted end-dialysis plasma water sodium concentration to be obtained. Nevertheless, this model is not suitable for routine clinical application, because of difficulties in the real-time determination of initial plasma water sodium concentration and 'effective' sodium dialysance. Measuring dialysate conductivity at the inlet and outlet ports of the dialyzer allows the estimation of sodium transfer during dialysis, if the function of concentration versus conductivity is known. If sodium transfer is measured at two different inlet dialysate conductivities, it is possible to determine ionic dialysance and systemic plasma water conductivity, which can be used routinely to apply the single pool sodium kinetic model. Given that ionic dialysance and plasma water conductivity can be measured easily repeatedly and inexpensively at each dialysis session without the need for blood sampling or laboratory determinations, it can be expected that conductivity kinetic models will soon become a part of everyday clinical practice.

Electric Conductivity↗