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A Magnasco

Publications and source records attributed to A Magnasco.

15 recordsLinked to original sources
PubMed2000

Glucose infusion test: a new screening test for vascular access recirculation.

BACKGROUND: Vascular access recirculation is an important cause of diminished dialysis efficiency. We propose a new screening test based on glucose infusion as a tracer for recirculation. METHODS: The glucose infusion test (GIT) protocol comprises a basal blood sample (A) from the arterial port, a 5 mL bolus of 20% glucose into the venous chamber (time 0), followed by a second sample (B) in four seconds (from 13 to 17 s with QB 300 mL/min) from the same port. The blood glucose level is determined at the bedside on A and B with a reflectance photometer (CV 1.8%). Interpretation of the test is straightforward: If B = A, there is no recirculation, whereas if B > A, recirculation can be calculated from the regression equation: 0.046 x (B - A) + 0.07, obtained from in vitro tests reproducing artificial recirculation at 0, 5, and 10%. To validate this new method in vivo, we compared GIT and the urea test on 39 hemodialysis patients, obtaining a good correlation (r = 0.93). The two tests were considered positive (recirculation present) when the lower 95% confidence intervals were more than zero. RESULTS: Our patients were divided into two groups: those with (22 out of 39, mean recirculation 11.8%) or without recirculation (17 out of 39, mean 0.06%). The urea test did not recognize 7 out of 22 patients because they had a small recirculation below the urea test limit of detection. CONCLUSIONS: GIT was more sensitive (detection limit 0.3%), simpler, and immediate in showing the results than the urea test. It is an accurate and low-cost technique for screening and follow-up of vascular access in a dialysis unit.

Catheters, Indwelling↗
PubMed1998

Four year experience in laparoscopic dissection of intact ovarian dermoid cysts.

BACKGROUND: Intraperitoneal spillage of dermoid cyst content, if not followed immediately by abundant peritoneal lavage, can cause a chemical peritonitis with subsequent adhesion formation. STUDY DESIGN: We performed an open clinical study in a university hospital. Forty-four consecutive ovarian dermoid cysts were removed intact from 40 premenopausal women operated on between October 1993 and December 1997. The laparoscopic technique included: 1) creation of a cleavage plane between the cyst and the ovary; 2) dissection of the cyst by a combination of water, scissors, and gravity without direct traction on the cyst; and 3) extraction of the cyst after its placement inside a laparoscopic bag. RESULTS: The mean cyst diameter was 6.5 cm (range 3 to 12 cm). Mean operating time was 125 minutes (range 50 to 180 minutes). All patients were discharged within 48 hours. The cysts were dissected completely intact and were extracted without spillage in the abdominal cavity in all cases. Operative followup was available in 15 of the 40 patients; mild adhesions were found on the treated ovary in 3 (20%). CONCLUSIONS: It is always possible to prevent rupture and spillage of dermoid cysts during laparoscopic operations, but this approach is time consuming and needs expert surgical technique.

Adult↗
PubMed1997

Comparison of a blocking vs. a flare-up protocol in poor responders with a normal and abnormal clomiphene citrate challenge test.

This study aimed to standardize the clomiphene citrate test (CC-t) in our laboratory while comparing two different protocols of controlled ovarian stimulation in poor responders. One hundred and forty-four patients scheduled for assisted reproductive techniques were submitted to the CC-t within 3 months before starting stimulation; 133 underwent controlled ovarian stimulation with a blocking protocol. Poor responders in the first cycle (n = 30) were subsequently treated with a flare-up protocol. Although it was not statistically significant, more patients reached oocyte retrieval with the flare-up protocol. In the completed cycles, more gonadotropin ampules (55 +/- 15 vs. 34 +/- 13; p < 0.001) and more stimulation days (12.6 +/- 1 vs. 11.6 +/- 1.2; p < 0.005) were needed in the blocking than in the flare-up protocol. No difference was observed in peak 17 beta-estradiol levels, preovulatory follicles, oocytes retrieved or pregnancy rate between the two protocols. According to the threshold values, established on CC-t of patients who obtained a clinical pregnancy (n = 44), the incidence of abnormal results was 10%. All but one patient with abnormal CC-t were poor responders during the first stimulation cycle. The flare-up protocol did not improve the ovarian response in these patients.

Adult↗
PubMed1993

Erythropoietin treatment and amino acid metabolism in hemodialysis patients.

A previous report suggests that treatment with recombinant human erythropoietin (rH-EPO) significantly improves many abnormalities in circulating amino acids (AA) in hemodialysis patients. We evaluated the effects of a 12-month treatment with rH-EPO (150-250 U/kg/week) on blood AA levels in 10 patients with chronic renal failure under regular dialytic treatment. During treatment, hemoglobin levels increased from 7.0 +/- 0.3 to 10.1 +/- 0.3 g/dl at 3 months remaining steady thereafter. Before the treatment, patients showed reduced levels of essential AA (EAA), mainly valine, leucine and threonine (p < 0.05-0.01); among non-EAA (NEAA), aspartate and serine were reduced, whereas glycine, alanine, proline, citrulline and cyst(e)ine were increased (p < 0.05-0.001). Val/Gly, Ser/Gly and Tyr/Phe ratios were low (p < 0.05-0.01). Total EAA and total NEAA (619 +/- 21 and 1,382 +/- 75 mumol/l, respectively, before the study) were unchanged (639 +/- 22 and 1,410 +/- 89 mumol/l, respectively) at 12 months. Abnormalities in AA levels observed before the treatment persisted throughout the study. Only serine increased at the end of the study (p < 0.05). In conclusion, contrary to what has been reported, treatment with rH-EPO is not associated with an amelioration of AA metabolism in hemodialysis patients.

Adult↗
PubMedDate not supplied

Pre-dialysis application of the glucose infusion test for recirculation detection.

Vascular access recirculation (R) is a well-known cause of decreased dialysis dose. In this paper a new easy protocol for R detection in pre-dialysis derived from the classic Glucose Infusion Test (GIT) is introduced. The pre-dialysis GIT (GIT-pre) is based on the glucose (5%, 10 ml) bolus injection directly into the venous needle and on a simultaneous withdrawal from the arterial needle. If the glucose value increases during the glucose bolus, R is present. This new protocol was validated on 29 chronic haemodialysis patients (20 AVFs, 7 CVCs, 2 PTFE grafts), comparing the glucose increase with the classic GIT during dialysis. Only one CVC had R with the blood lines in the normal position (deltaglu = 465 mg/dl with GIT-pre and a deltaglu = 186 mg/dl, R = 9.3% with classic GIT) while in the reverse blood line position, all CVCs showed a significant glucose increase (mean GIT-pre deltaglu = 195 mg/dl; mean GIT deltaglu = 140 mg/dl corresponding to a R = 8%). There were 5 AVFs with true R (correct blood lines position) clearly identified by both methods (mean values deltaglu = 316 mg/dl with GIT-pre and a deltaglu = 390 mg/dl, R = 19.5% with classic GIT). Preliminary results show good reliability of the new protocol in identifying VA R caused either by failing VA with stenosis or by reverse blood lines position. The GIT-pre is a simpler application of the classic GIT useful for testing new VA, new needle positions or CVC performance before starting dialysis. A simpler R test could increase the frequency of the measurements and consequently the power of R in early detection of VA problems.

Arteriovenous Shunt, Surgical↗
PubMedDate not supplied

[Hemodialysis access recirculation].

Vascular access recirculation (R) allows the evaluation of the adequacy of the extracorporeal blood circuit in dialysis patients. The test verifies the correct needle position in patients with arterovenous fistulae (AVF) and the effective function of central venous catheters. In clinically uncomplicated native fistulae, a normal R test could avoid more complex procedures like blood flow measure or angiography. The AVF recirculation has two components, vascular access recirculation (AR) and cardiopulmonary recirculation (CPR). While the first phenomenon is well known, the second remained undetected for many years resulting in wrong R calculations with false positives. Using the correct formula, the great majority of AVF resulted in zero recirculation. The presence of R reduces the dialysis efficiency to critical levels, mainly in unsuspected cases. Among the numerous available R tests, the urea test is the oldest and historically the most commonly used method, but unfortunately it is labor intensive, with low sensitivity and specificity and with delayed results. The "ultrasound dilution"method is considered the gold standard, easy to perform, with good repeatability, but it is expensive requiring a specific device. Finally, the glucose infusion test (GIT) is a new low-cost test with immediate results and a very low detection limit, with good repeatability and high specificity and sensitivity.

Humans↗