bluuebunny/crossref_metadata_2025 huggingface dataset:
Uncomplicated Central Vein Catheterization of High Risk Patients with Real Time Ultrasound Guidance
Authors: Gallieni M. , Cozzolino M.
Published: March 2018

Internal jugular vein cannulation has become a routine and clinically important aspect of medical care of critically ill patients. The landmark guided technique usually affords rapid and easy vascular access, but is not always successful and may be complicated by arterial puncture, hematoma, or pneumothorax. Some categories of patients, in particular patients with no external landmarks and patients with coagulopathies, appear to be at an increased risk of complications. We report the experience of internal jugular vein cannulation by a single operator with the external landmark technique in 10 patients and with ultrasound guidance in 31 patients, including 12 high risk patients. These patients had severe coagulopathies due to hepatic failure, HELLP syndrome, excess of anticoagulation treatment, or they had no external anatomic landmarks because of anasarca or obesity, were unable to maintain the horizontal position, or were external landmark catheterization failures. With the availability of the ultrasound device, success and complication rates improved markedly, suggesting that the ultrasound technique is easy to learn and rapidly produces an improvement over the external landmark method. In particular the 13 cannulations performed in 12 high risk patients were all successful at the first attempt, with no complications. In the overall population successful cannulations improved from 80% to 100%, first attempt success from 20% to 87% and carotid punctures decreased from 33% to 3.2%. Our results confirm that ultrasound guided cannulation of the internal jugular vein allows safer operation in high risk patients or when access problems are anticipated.
Intraoperative Blood Salvage (IOBS) in Cardiac and Vascular Surgery
Authors: Valbonesi M. , Carlier P. , Florio G. , Morelli F. , Ruzzenenti M.R.
Published: March 2018

The extensive application of IOBS has permitted a great reduction in the use of homoglous transfusion which presently represents the largest field of application of autologous systems. In cardiac and vascular surgery, IOBS is particularly useful to the goal of preventing the transmission of viral disorders and other adverse effects related to homologous transfusions. The apparatuses for IOBS may also be used to perform hemodilution and sequestration of a desired amount of platelet rich plasma. The appropriate usage of drugs in perioperative period and the promotion of hemostasis with IOBS are important costituents for the correct transfusional management of the patient. The feasibility and safety of IOBS is known and in expert hands it is an optimal method for the transfusional treatment of surgical patients
From Low Hematocrit Physiology to Isovolemic Hemodilution
Authors: Oriani G. , Sacchi C. , Borghi B.
Published: March 2018

The aim of this study, starting from some concepts of physiology, was to deal with the ever growing question of intentional anemia. Physiology suitably expresses the linear relationship between hematocrit and blood fluidity, and at the same time explains how viscosity and aggregability are important co-factors in the circulation, in disease and in thromboembolic complications. The need to understand how a low hematocrit level, compared to the volemia, is a fundamental requirement in surgery, and even more so in surgery with a high risk of embolism, like orthopedic traumatology surgery. Normovolemic hemodilution was analyzed both for the risks it involves and for how much it sticks to the changes induced by a similar situation on the various organs and apparatus. The authors, based on their experience in the field of anesthesiology, propose an operating schedule to safely perform intentional normovolemic hemodilution, describing the preoperative, intraoperative and finally the postoperative period. In conclusion, the authors advocate a wider use of this technique, confirming its safety in relation to volemia.
Blood Saving Program: A Multicenter Italian Experience
Authors: Borghi B. , Oriani G. , Bassi A.
Published: March 2018

To assess the causes of failure in a blood saving program and the consequent need for homologous transfusions during major orthopedic surgery, data were collected from six orthopedic centers where an autotransfusion program was carried out from 1992–1994. The 1,576 (1,016 female and 560 male) patients studied (average age 63.6 ± 10 years) were treated either for total hip prosthesis (1,144 pts) total knee prosthesis (212 pts), plate and screw removal plus hip prosthesis (8 pts), hip revision (cup 48 pts, stem 10 pts, cup plus stem 146 pts) and total knee revision (8 pts). Ninety percent of patients did not undergo homologous transfusions, which was significantly connected to: male sex (8% versus 11.7% p=0.02), younger age (63.2 vs 66.9 years, p=0.0001), higher weight (male 76 vs 70.7 Kg. p = 0.003, female 65.6 vs 61.9 Kg. p = 0.0003); higher baseline Hb (13.9 vs 12.8 gl dl, p = 0.0041), shorter operation time (110 vs 128 minutes, p = 0.0001); use of indobufen for antithromboembolic prophylaxis (indobufen 4.6% vs heparin calcium 15.2% vs low molecular weight heparin 9% p = 0.0001). On the contrary, the factors favoring homologous transfusions were: peripheral anesthesia (spinal and epidural 15.3% vs general 9.3% vs integrated 9.8% p = 0.016), total hip or knee revision, fixation device removal before hip prosthesis, systemic hypertension and coronary heart disease.
Anaesthesia and Autologous Transfusion
Authors: Borghi B. , Bassi A. , Grazia M. , Gargioni G. , Pignotti E.
Published: March 2018

The anaesthesiologist plays a central role in co-ordinating the combined application of the various blood saving techniques. In fact, to carry out transfusion therapy correctly, the anaesthesiologist must plan the right number of units of predeposit blood during the first examination, estimate the salvage of intra and post operative blood loss and spread the infusion of the units over the first three days in order to keep the patient in a state of haemodilution. From January 1992 to June 1994 in the department of anaesthesia and the intensive care unit, 980 patients were treated for total joint replacement: 714 total hips (7 after removal of plates and screws) 145 revisions, and 121 total knee prostheses. Basal Hb was 13.4 ± 1.4 g/dl (range 6.7 – 17.9 g/dl). Homologous transfusions were carried out in 6.3% of these patients. The need to use homologous transfusions was negatively influenced by female sex, coronary heart disease (p = 0.005), length of surgery and type of antithromboembolic prophylaxis (indobufen has a significantly low incidence - p = 0.0001 - compared to calcium heparin or low molecular weight heparin).
Biopolymeric Modification of Superoxide Dismutase (mPEG-SOD) to Prevent Muscular Ischemia-Reperfusion Damage
Authors: Giardino R. , Capelli S. , Fini M. , Giavaresi G. , Orienti L. , Veronese F.M. , Caliceti P. , Rocca M.
Published: March 2018

The efficacy of preventing ischemia-reperfusion damage by employing native or modified (mPEG-SOD) superoxide dismutase in an experimental animal model of acute ischemia of the left hindlimb was tested. Four hours and thirty minutes complete warm ischemia was induced in the left hindlimb of 43 Wistar rats, by clamping the femoral artery and monitoring its efficacy with Laser Doppler flowmetry. After ten days, a significative difference (p=0.004) of the survival leg rate was found in the group treated with mPEG-SOD (86.6%) compared with the control group (30%). Histomorphological and ultrastructural analysis were performed at different time intervals confirming what the clinical course had already pointed out. These results show that SOD in its modified form, despite the lower dosage, can provide good protection against ischemia/reperfusion injury of muscles.
Can the Artificial Heart Make the Circulation Become Fractal?
Authors: Yambe T. , Nanka S. , Naganuma S. , Kobayashi S. , Akiho H. , Kakinuma Y. , Ohsawa N. , Nitta S. , Fukuju T. , Miura M. , Uchida N. , Tabayashi K. , Tanaka A. , Yoshizumi N. , Abe K. , Takayasu M. , Takayasu H. , Yoshizawa M. , Takeda H.
Published: March 2018

In order to analyze the hemodynamic parameters in prosthetic circulation as an entity and not as decomposed parts, non linear mathematical analyzing techniques, including the fractal dimension analyzing theory, were utilized. Two pneumatically actuated ventricular assist devices were implanted, as biventricular bypasses (BVB), in chronic animal experiments, using four healthy adult goats. For the comparison between the natural and prosthetic circulation in the same animals, the BVB type complete prosthetic circulation model with ventricular fibrillation, was adopted. All hemodynamic parameters with natural and prosthetic circulation were recorded under awake conditions, and calculated with a personal computer system. Using the non-linear mathematical technique, the arterial blood pressure waveform was embedded into the return map as the beat-to-beat time series data and fractal dimension analysis were performed to analyze the reconstructed attractor. By the use of the Box counting method, fractal dimension analysis of the hemodynamics was performed. Return map of the hemodynamics during natural and artificial circulation showed fractal characteristics, and fractal dimension analysis of the arterial blood pressure revealed the fact that lower dimensional fractal dynamics were evident during prosthetic circulation. Fractal time series data is suggested to have robustness and error resistance, thus our results suggest that the circulatory regulatory system with an artificial heart may have these desired characteristics.
Therapeutic Use of Albumin
Authors: DE Gaudio A.R.
Published: March 2018

The clinical use of albumin solutions is a controversial issue, that involves albumin as a volume plasma expander, a supplement of total parenteral nutrition and a substance with pharmacological properties. The aim of this review is to show the present role of albumin in the clinical setting. We reviewed experimental and clinical data collected by the Medline System and the bibliographies of relevant articles. Experimental studies were selected on the basis of their historical value and applicability (hypothetical use, correct use) to the clinical setting. At present, it is possible to assert that: a) exogenous albumin is not an ideal colloid; b) the effects on plasma volume expansion are not entirely predictable, especially in pathologic states accompanied by leaky capillary membranes; c) albumin supplementation shows no benefit on many kinds of tissue edema; d) the supplementation of albumin has no influence on outcome. It is possible to demonstrate the role of albumin as a substance with unique properties that make it useful, but further experimental and clinical data will be necessary and represent new areas for future exploration. Given the protein's cost, the routine use of albumin does not appear to be justified, until new data indicate otherwise.
On-Line Estimation and Prediction of Urea Kinetics during Hemodialysis: A Simulation Approach
Authors: Comai G. , Cappello A. , Grandi F. , Avanzolini G.
Published: March 2018

A new method for the on-line estimation of urea kinetic parameters from blood urea concentration (BUN) continuously measured during a dialysis session is proposed. The method, based on the variable-volume double-pool model, is evaluated through a simulation approach in order to easily consider a large set of well-controlled test conditions. The model is characterized by six parameters, knowledge of which enables early prediction of the end dialysis urea concentration and the dose of dialysis. The sensitivity of the model predicted BUN with respect to the parameters was first analyzed to investigate which can be reliably estimated from blood urea measurements taken at a suitable rate. This analysis showed that the model predicted BUN is highly sensitive to the initial blood urea concentration and to the dialyzer clearance, normalized with respect to the total initial distribution volume, while it is scarcely influenced by the normalized ultrafiltration and urea generation rates. The new on-line estimation technique keeps these two last parameters constant and takes advantage of an original analytic solution of the second order urea kinetics. The results of the estimation process on realistic simulated data showed that the proposed method provides early and reliable estimates of the normalized clearance and of the end dialysis concentration. The transcellular mass transfer coefficient and the intra-extra cellular volume ratio can also be estimated, although with less accuracy. Moreover, it was shown that the use of the single-pool model, instead of the double-pool one, provides systematic errors on the estimates.
LDL-Apheresis in Two Patients with Extremely Elevated Lipoprotein (a) Levels
Authors: Bambauer R. , Schiel R. , Keller H.E. , Latza R.
Published: March 2018

Hyperlipidemia and elevated lipoprotein (a) [Lp(a)] levels have been linked to the development and progression of premature atherosclerosis. Two male Caucasian patients (36 and 42 years old) with heterozygous familial hypercholesterolemia and extremely elevated Lp(a) concentrations, resistant to diet regimen and lipid lowering drugs, were treated with LDL-apheresis for 55 months (liposorber system, KanekaR, Japan) and 15 months (immunoadsorption system, special Lp(a) columns, LipopakR, Pocard, Russia). Lp(a) dropped on average by 50%, total cholesterol by 27%, LDL-cholesterol by 42%, triglycerides by 43% and the fibrinogen concentration by 16%. Prior to treatment, both patients had suffered three myocardial infarctions. Four and six coronary angiographies with two and four percutaneous transluminal angioplasties (PTCA) were necessary. Since the treatment with LDL-apheresis neither myocardial infarctions nor cardiac complaints have been observed, and both patients have reported better performance. Available data suggest that LDL-apheresis may be effective in the treatment of patients with extremely high Lp(a) concentration.
Protein Layer on Hemodialysis Membranes: A New Immunohistochemistry Technique
Authors: Panichi V. , Casarosa L. , Gattai V. , Bianchi A.M. , Andreini B. , Migliori M. , DE Pietro S. , Giovannini L. , Palla R.
Published: March 2018

In order to investigate the nature of the protein layer deposited on hemodialysis membranes we developed a direct immunohistochemical technique using fluoresceinated antibodies to plasma proteins. Fifteen patients on regular dialytic treatment were dialyzed with CU, HE, PAN, PS and PMMA and the dialyzers analyzed at the end of a standard dialytic session. Snap frozen sections of hollow fiber devices were treated with flourescein-isothiocyanate conjugated antibodies for IgG, IgA, IgM, C3c, fibrinogen, factor VIII, factor Xllla-s, antithrombin III, fibrinogen degradation products (PDF) and plasminogen. Protein deposits were evaulated by a quantitative criteria, which evaluates the intensity of fluorescence and the area of the capillary wall occupied by this fluorescence by using an image analysis software. The coagulation cascade is activated by all membranes and similar deposits of these proteins were revealed, whereas important differences in C3c deposition were found.
Endocrine Effects of Erythropoietin
Authors: Carlson H.E. , Graber M.L. , Gelato M.C. , Hershman J.M.
Published: March 2018

Uremic men may manifest a variety of hormonal abnormalities, including decreased serum concentrations of testosterone and thyroid hormones and increased serum levels of growth hormone and prolactin. Some previous investigations have reported that erythropoietin therapy may reverse these hormonal changes. To investigate this possibility further, we measured serum prolactin, testosterone, LH, FSH, TSH, free thyroxine, triiodothyronine, growth hormone and IGF-I in 21 generally elderly male hemodialysis patients before and during erythropoietin therapy; many of the patients also received an anabolic steroid or metoclopramide treatment. Despite a significant erythropoietic response in a majority of the subjects, no significant changes were seen in any of the hormonal parameters other than a small decrease in serum growth hormone concentrations. Advanced age and chronic illness in our patients may have played a role in limiting the hormonal response reported by others.
Effect of Donor Strains and Age of the Recipient in the Use of Microencapsulated Hepatocytes to Control Hyperbilirubinemia in the Gunn Rat
Authors: Bruni S. , Chang T.M.S.
Published: March 2018

Hepatocytes of certain rat strains are spontaneously accepted when they are implanted in the peritoneal cavity. Therefore to evaluate if microcapsules are able to immunoisolate the hepatocytes, it is necessary to find the strain of rat whose free hepatocytes are rejected. Hepatocytes were collected from Buffalo rats and were implanted intraperitoneally in one year old Gunn rats. During the first two weeks both groups of Gunn rats which received free and encapsulated hepatocytes showed a reduction in the bilirubin level relative to the control. After 15 days, the bilirubin levels increased in the group which received free hepatocytes. This suggests that an acute rejection had taken place. Bilirubin continued to stay high until the end of the experiment and there was no difference between this group and the control. As the animal ages, there is a significant accumulation of bilirubin in the tissues which affects the net reduction of serum bilirubin since once bilirubin is conjugated by the transplanted hepatocytes and eliminated, some of the bilirubin deposited in the tissues diffuses into the blood preventing a major drop in serum bilirubin levels. The findings that UDP-glucuronosyltransferase (UDPGT) activity of Buffalo rat hepatocytes is the same as the UDPGT activity of Wistar rat hepatocytes, imply that the age of the animal is a very critical factor in determining how great the depression of serum bilirubin will be after implantation of hepatocytes.
The Correlation between Protein Catabolic Rate and Kt/V in Hemodialysis is not a Mathematical Artifact
Authors: Buur T. , Smye S.W. , Bradbury M. , Will E.J.
Published: March 2018

To test whether the demonstrated correlation between Kt/V urea and normalised protein catabolic rate (NPCR) is caused by a mathematical artifact, we examined 12 adult and 8 paediatric haemodialysis patients. Kt/V was determined by the classical method. As an equivalent of NPCR we measured normalised urea generation rate (NUGR) by a one-week collection of dialysate and urine using total body water estimated by bioelectrical impedance for normalisation. The correlation between Kt/V and NUGR was 0.58 (all), 0.55 (adults), and 0.62 (children). Since the determination of Kt/V and NUGR are not interdependent, we conclude that the correlation between Kt/V and protein catabolism is not artifactual.
The Production of Platelet-Activating Factor (PAF) during Hemodialysis with Cuprophane Membrane. Does the Calcium Concentration in the Dialysate Play Any Role on It?
Authors: Iatrou C. , Afentakis N. , Antonopoulou S. , Andrikopoulos N. , Demopoulos C.A. , Ziroyannis P.
Published: March 2018

There is evidence that PAF may be produced during hemodialysis (HD) mainly when using cuprophane membrane (CU). It is also known that PAF production is dependent on the amount of extracellular calcium (ECa2+). In the present study, we investigated the production of PAF during HD with CU as well as the role of the Ca2+ in the dialysate with respect to PAF production. Five hemodialyzed patients were studied in two consecutive HD sessions (the first performed using dialysate without Ca2+ and the second with a Ca2+ concentration of 3.25 mEq/L) and at different times during the sessions the circulating PAF levels as well as the leukocyte and platelet counts were measured. The results demonstrated that a) PAF was indeed produced during HD with CU, b) the highest PAF levels in blood were observed between 5 and 15 minutes from the beginning of HD, at which time the lowest circulating leukocyte and platelet count were measured and c) PAF levels in blood were inversely proportional to the Ca2+ concentration in the dialysate (with the exceptional case of the 15 minutes), although we expected the opposite results.
Is Ace Inhibitor Treatment a Possible Cause of Better Cardiovascular Remodelling in Well Functioning Kidney Transplant?
Authors: LA Manna G. , Campieri C. , Dalmastri V. , Buscaroli A. , Tarquinii M. , Giudicissi A. , Neri L , Pace G. , Mosconi G. , Scolari M.P. , Stefoni S. , Bonomini V.
Published: March 2018

Diseases of the cardiovascular system are a common cause of death in renal transplanted patients. In this study we assessed the echocardiographic morphological and functional findings after renal transplantation of two homogenous groups of transplanted patients with normal renal function. The first (A) with spontaneously normotensive patients, the second (B) with moderate hypertension treated mainly with Ace inhibitors. Analysis of these data highlights two noteworthy results: the similar left ventricle hypertrophy found in both groups and the existence of better diastolic compliance among the hypertensive transplanted patients. If this is confirmed by studies currently in progress, the importance of Ace-inhibitors treatment in remodelling cardiac dysfunction after long term dialysis treatment might be seriously considered.
Hemolysis with the F21 Hemopump
Authors: Wiebalck A. , Flameng W.
Published: March 2018

The aim of this study was to determine the influence of mechanical factors on free hemoglobin using an F21 hemopump cannula. These factors (flow, rotary speed, reduction of the cross section area of the silicone tube and foreign material on the screw) were tested in a mock circulation with ox blood. Irrelevant increases in free hemoglobin were induced by foreign bodies either in the inlet or on the screw. The hemopump flow was easily affected and almost suppressed by small amounts of foreign bodies on the screw. Other reasons for elevated concentrations of plasma free hemoglobin may imply a general disorder of the pump, anticoagulation, renal function, red cells or a combination of these factors
Non-Machinery-Based System for Cell-Free, Concentrated Autogenous Ascitic Fluid Reinfusion
Authors: Katoh S. , Kojima T. , Morimoto S. , Inoue K. , Ida K. , Nakaji S.
Published: March 2018

A non-machinery-based system for the reinfusion of ascitic fluid was developed and assessed. In fundamental studies utilizing bovine serum, this procedure proved economical, quick and useful. The most suitable filter was PS-R (#405-2). Bovine serum with a protein concentration below 3.0 g/dl was treated using this system. Samples containing blood (prepared to 0.5% hematocrit) were also treated, but the treatment time required was double that of serum with the same protein concentration. In both cases the protein recovery ratios were about 90%. We conducted clinical studies on 62 occasions (machinery-based system; 31 times, non-machinery-based system; 31 times) on 19 cases of ascites refractory to treatment with various drugs including diuretics. Clarification of the differences between the non-machinery and the machinery-based system, indicated the former to be superior. This new procedure is easier because of its use of no machinery, and the high protein recovery ratio proved its usefulness.
Effects of Automatic Blood Volume Control over Intradialytic Hemodynamic Stability
Authors: Mancini E. , Santoro A. , Spongano M. , Paolini F. , Zucchelli P.
Published: March 2018

Due to the crucial role of hypovolemia in the genesis of dialysis-induced hypotension, we have evaluated whether the automatic control of the intradialytic blood volume (BV) decrease along a preset trajectory might be beneficial to the hemodynamic stability during treatment. Five frequently hypotensive HD patients were studied and a 3-period-protocol (A1-B-A2) was adopted, each period lasting 6 sessions per patient. During the B periods the patient BV decrease was kept along a predefined profile, thanks to an automatic system with a retroactive control of both the ultrafiltration rate (UFR) and dialysate conductivity (DC); instead, during the A periods, conventional HD was performed, with linear UFR and constant DC, inducing a spontaneous decrease in BV. The intradialytic BV behaviour was much more stable during the B-periods (-10.2 ∓ 1.4% by the end of the treatment) than during the A1 (-11.2 ∓ 3%) and A2 periods (-11.5 ∓ 2.5%). Only one dialysis-hypotension episode was observed during the B periods, compared to 8 and 5 during the A1 and A2 periods, respectively (p ≤ 0.05). The automatic control of the BV changes during dialysis could improve the intra-treatment cardiovascular stability in critically-ill patients.
Non-Invasive Monitoring of Hemodynamic Parameters during Hemodialysis
Authors: Pizzarelli F. , Dattolo P. , Piacenti M. , Morales M.A. , Cerrai T. , Maggiore Q.
Published: March 2018

We studied in 13 hemodialysis patients intradialytic variations of blood volume (BV) and cardiac output, by means of non-invasive methods. We found a weak correlation, r 0.2 or less, between BV variations and intradialysis blood pressure variations. The sensitivity of the former in describing the variations of the latter was only 32%. During the 30 min preceeding the hypotensive crisis the percent BV variations did not show any predictive trend. On the contrary, refilling increased as blood pressure dropped and a weak inverse relation (r -0.35) was found between these two parameters. Unstable patients had predialytic blood volume values significantly lower than stable ones and comparable to healthy subjects. On the contrary, the correlation between percent variations of cardiac output index and MAP was 0.68 with a sensitivity and specificity of 90% and 59%, respectively. Unfortunately these promising results were obtained only with an estimate of cardiac output obtained by echocardiography and not by transthoracic impedance cardiography, which is much more feasible than the former as on-line monitoring of cardiac output. On-line monitoring of hemodynamic parameters is an appealing but still unsolved task.
Autonomic Nervous Function and Blood Volume Monitoring during Hemodialysis
Authors: Enzmann G. , Bianco F. , Paolini F. , Panzetta G.
Published: March 2018

We studied the autonomic reflex response to hypovolemia during HD by means of spectral analysis of heart rate variability (SAHRV) in 10 hypotension prone (group A) and 10 hemodynamically stable patients (group B). UF rate normalized per total body water and blood volume fall were similar in the two groups. The sympatho-vagal balance index, calculated as the ratio between the integrals of the spectrum in the low (0.02-0.15 Hz) and in the high frequency range (0.2-0.35 Hz) rose in group B progressively from the beginning of the treatments, reaching a top at the 90th minute and remained subsequently high until the end. On the contrary this index did not show remarkable increases in group A. The differences between the two groups were statistically significant at 0 (4.6∓2.9 vs 1.5∓1.3), 60th (8.3+7.8 vs 2.2+2.6), 90th (17.9+13.4 vs 3.7+2.8), 150th (8.8+3.7 vs 2.7+2.8) and 210th minute (8.6+5.0 vs 2.9+2.5). In conclusion SAHRV shows an impairment of autonomic reflex response to hypovolemia in hypotension-prone patients.
Blood Volume Modeling and Refilling Rate Estimation in Hemodialysis by Continuous Hemoglobin Monitoring
Authors: Arrigo G. , Bucci R. , Colasanti G. , Rustici A. , Sivo M. , Rizza V. , D'Amico G.
Published: March 2018

Eleven bicarbonate hemodialyses (HD) of 6 patients under constant ultrafiltration were continuously monitored with an optical Hb-meter, considered to be a marker of blood volume (BV) changes. A theoretical model was fed experimental data for prediction of blood volume and estimation of vascular parameters, and a time course of rate of refilling was extrapolated. The adequacy of the model was very good for the time course of BV prediction (r2=0.85-0.95, n=11) and for plasma protein concentration (r2=0.83-0.86, n=2). Parameters estimated included (mean-DS): filtration coefficient (Cf)=0.22 (0.16) dl/min∗mmHg, transcapillary hydrostatic pressure (DP)=17.80 (3.44) mmHg and protein concentration of the refilling fluid (Cref)=0.45 (0.30) g/dl. In conclusion our study has shown that the model chosen fits the observed BV profile well in all cases, thus the Hb data series can be used for BV dynamic modeling and for estimation of vascular parameters.
A New Approach to Blood Pressure and Blood Volume Modulation during Hemodialysis: An Adaptive Fuzzy Control Module
Authors: Nordic M. , Giove S. , Lorenzi S. , Marchini P. , Saporiti E.
Published: March 2018

The paper proposes a fuzzy logic based procedure able to control as far as possible the behaviour of the blood pressure of a patient during a dialysis session, allowing him to reach the foreseen dry weight. A PI discrete-time fuzzy control is used in order to compare the controlled variables concerning the (blood pressure and blood volume) to the reference values. Two different reference tables, concerning the pressure and volume errors and rates are introduced, then the proposed control actions are mixed in order to obtain the final value (net ultrafiltration rate). A smooth function of volemia acts on the second control variable, Na concentration in the dialysate. The adaptive control system was simulated on an IBM-PC, rules and terms were expressed by linguistic judgements like: IF “situation”, THEN “action”. A pre-processor converts the rules into the numerical values of the reference tables. The obtained simulation results are satisfactory, the introduction of the Na control allows reaching the target dry weight of the patient with a stable blood pressure.
Continuous On-Line Determination of Recirculation by Thermodilution in Hemodialysis Patients
Authors: Bonforte G. , Dozio B. , Scanziani R. , Crema G. , Surian M.
Published: March 2018

The Consistency Of The Determination Of A-V Fistula Recirculation (R) Using The Thermodilution Method (T) With A New Probe (Blood Temperature Monitor, Btm Fresenius A.G.) Was Studied In 32 Patients (Avf: Proximal 34%, Distal 63%, Graft 3%). We Compared R Calculated By T With Both The Traditional Three-Sample Method (C) And The Low-Flow Three-Sample Method (L); Both Bun And Creatinine (Cr) Were Measured In All Samples At The Beginning And At The End Of The Session. T Was Also Determined At The 2Nd And 3Rd Hour. There Was A Significant Correlation Between T And Either C Or L At The Start Of The Session (Bun And Cr) As Well As At The End (Only Cr). R Was Higher (11.9±10) In Proximal Avf Than In The Distal (5+3.1%; P0.01) When Measured By T At The Same Blood Flow (Qb: 313±45 Vs 343+52 Mls/Min, P=Ns). T Increased But Not Significantly By Increasing Qb From 150 To 300 Mls/Min In Ten Patients. No Correlation Was Found During The Session Between Blood Pressure And T Variations. In Conclusion, T And L Give Very Similar Results While C Overestimates Recirculation. R Is Easy To Perform Repeteadly By T With Results Available Online.
On-Line Urea Monitoring: A Further Step towards Adequate Dialysis Prescription and Delivery
Authors: Ronco C. , Brendolan A. , Crepaldi C. , Frisone P. , Ghiotto F. , Zamboni S. , Gastaldon F. , La Greca G.
Published: March 2018

The Aim Of This Study Is To Present A Clinical Experience Carried Out With A New Device Designed To Measure On-Line Urea Nitrogen Concentration In The Effluent Dialysate. The Biostat 1000® Urea Monitor (Baxter Healthcare, Dirfield, Iii, Usa) Was Utilized In The Present Study. The Monitor Is Based On The Principle That Multiple Urea Measurements In The Dialysate Effluent From The Dialyzer, Permit To Built A Double Exponential Regression Leading To The Urea Kinetic Parameters Of The Dialysis Session. Data Obtained With The Urea Monitor Were, In The Present Study, Compared With Those Obtained By Direct Measurements Carried Out In Blood And Dialysate And By The Collection Of The Whole Amount Of Spent Dialysate. The Monitor Provided An Accurate Value Of Predialysis Bun Without Any Blood Drawing. Urea Kinetics Were Established From Multiple Dialysate Measurements And No Blood Drawing Was Necessary. The Double Pool Kinetics Were Taken Into Account And Kt/V, Pcr And Sri° Obtained Were Comparable To Those Obtained From Direct Measurement. Since A Projected Value Of Kt/V Can Be Obtained, The Monitor Could Represent A Potential Source Of Information To Detect Possible Filter And Machine Dysfunction, As Well As High Rate Of Recirculation.
On-Line Dialysate Urea Monitor: Comparison with Urea Kinetics
Authors: Alloatti S. , Molino A. , Manes M. , Bonfant G. , Bosticando G.M.
Published: March 2018

The outputs of a new on-line dialysate urea monitor (UM) were compared to a urea kinetic model (UKM) and to dialysis direct quantification (DDO) in 13 patients. As for urea extraction and predialysis urea level, a good degree of correspondence was found between UM and laboratory data. Kt/VUM (1.21) is intermediate between Kt/VUKM (1.28) and Kt/VuKM using the post-rebound urea value (1.14) or Kt/VDDQ (1.14). Passing and Bablok regression analysis indicated no systematic error between Kt/VUM and Kt/VDDQ. The percentage differences in nPCR by UM, UKM and DDQ were not significant, but the standard deviations were wide. The UM approach is very simple and practical, avoiding blood sampling, laboratory analysis and data handling. It is reliable enough for clinical practice. Compared with traditional urea kinetics, Kt/V computation by a mathematical elaboration of the dialysate urea profile drawn from several points theoretically invites fewer errors due to the analytical procedure.
A Modified Two-Bun Method for Routine Urea Modeling: Clinical Validation in 120 Patients on a Free Diet
Authors: Casino F.G. , Lomonte C. , Russo R. , Di Iorio B. , Chiarulli G. , Manno C. , Lopez T.
Published: March 2018

Recently, a modified algorithm of the Two-BUN method (MA2p), avoiding dialyzer clearance measurement, was presented for routine assessment of Kt/V and NPCR. To validate MA2p in patients on a free diet (FDP), we studied 120 stable dialysis FDP by measuring Kt/V and NPCR with both MA2p and a modified version of the standard Three-BUN method (MA3p), for the 3 weekly sessions. The NPCR values (g/kg/day), calculated by MA3p for the 3 interdialyses were: 1.286∓0.274, 1.256∓0.276, and 1.116∓0.230, respectively. The correlation coefficient (r) for averaged Kt/V values obtained by the two methods was 0.999 and the percent error (Error%) for MA2p vs. MA3p results ranged from -1.5 to +0.78%. The respective results for NPCR were: r=0.967, Error% range from -11.7 to +13.9%. In conclusion, MA2p can be safely used in patients on a free diet. The lowest NPCR values were observed during the long interdialysis.
The Influence of Lung Injury due to Mechanical Ventilation on the Initiation of Ecmo
Authors: Bartsch H. , Kössel H. , Brummer G. , Philippi W. , Waldschmidt J. , Eyrich K. , Versmold H.
Published: March 2018

Before the entry criteria for extracorporeal membrane oxygenation (ECMO) are met, newborns may require aggressive mechanical ventilation which may result in lung injury. The question arises whether the presence of a pneumothorax in these infants plays a role in the prognosis. Of the 21 newborns transferred to our hospital for ECMO, 8 were treated with ECMO. 9 of the 21 newborns developed a pneumothorax with conventional ventilation and 6 of these 9 newborns subsequently required ECMO. Infants who developed a pneumothorax but did not meet ECMO criteria and remained in the oxygenation index (01) range between 25 and 40 for more than 2 days had a poorer prognosis. If adequate oxygenation cannot be attained with acceptable mechanical ventilation and a more aggressive ventilation results in a pneumothorax, ECMO should be considered even if the oxygenation index is below 40.
Extracorporeal Membrane Oxygenation with Veno-Venous Bypass and Apneic Oxygenation for Treatment of Severe Neonatal Respiratory Failure
Authors: Somaschini M. , Bellan C. , Locatelli G. , Glauber M. , Colombo A.
Published: March 2018

Seven newborn infants with life-threatening respiratory failure were treated with veno-venous (V-V) extracorporeal lung support and apneic oxygenation after maximal ventilatory and pharmacological treatment failed. Diagnosis were meconium aspiration syndrome in 3 cases, respiratory distress syndrome in 2, sepsis in 1, congenital diaphragmatic hernia in 1. Before ECMO 6 infants received tolazoline, 4 surfactant, 3 high frequency ventilation, 1 prostaglandin E, 1 epoprostenol, 2 nitric oxide. Newborns were highly hypoxemic at admission and all but one underwent rescue cannulation. V-V bypass was performed with a single lumen single cannula and tidal flow was generated by an alternating clamp using a non-occlusive roller pump. The mean duration of bypass was 162, 4±162.3 hours and infants were extubated 94.5±74.8 hours after decannulation. Five newborns survived and two died. Growth and neurologic development of the older children is normal. The extracorporeal lung support with V-V bypass associated with apneic oxygenation was effective in reversing severe neonatal respiratory failure unresponsive to maximal ventilatory and pharmacological support. An early referral, prior to meeting ECMO criteria, is important in order to avoid hypoxic complications preceding ECMO.
Follow-up in Neonatal Extracorporeal Membrane Oxygenation (ECMO)
Authors: Geven W.B. , Nabuurs-Korhman L.A.J. , van Kessel-Feddema J.M. , Festen C.
Published: March 2018

In 34 survivors of the first 43 ECMO patients from our institution before discharge to another hospital or home an EEG, BAER, Head Ultrasonography, cerebral CT scan, Dubowitz score and ophthalmological inspection were performed. At one year of age Mental Developmental Index of the Bayley scales, Motor Quotient as well as pulmonary and neurological status were assessed. In 29 patients follow-up took place in our hospital. In 17 of them (59%) all tests before discharge were normal, 2 patients (7%) showed an abnormal BAER, an additional 5 patients (17%) had abnormal EEG and 2 patients (7%) had abnormal HUS in combination with abnormal cerebral CT scan. In 19 patients (33%) the Dubowitz score was abnormal at discharge. At one year of age neurological status was normal in 25 (86%) patients, respiratory status was normal in 22 (76%) and Mental Development Index was > 80 in 23 of the patients (79%). A significant correlation between Mental Development Index and Motor Quotient was found r=0.50, p=0.0065. It is concluded that more than one abnormal neurophysiological test before discharge may identify patients with additional risks for adverse outcome and that the respiratory status influenced psychomotor development at one year of age.
Treatment of Severe Non-Neonatal ARDS in Children with Surfactant and Nitric Oxide in a “PRE-ECMO”-Situation
Authors: Möller J.C. , Schaible T.F. , Reiss I. , Artlich A. , Gortner L
Published: March 2018

The use of exogenous surfactant and nitric oxide in neonates has reduced the number of infants requiring ECMO. The purpose of this study was to demonstrate whether these two therapeutic options might reduce the number of over 28 days old children with severe ARDS requiring ECMO, without reducing changes of survival and morbidity. Over a 30 month period all non-neonatal ARDS patients transferred to our institution for ECMO evaluation were treated based on a study-algorithm. If they did not fulfill “fast entry criteria” (paO2< 40 for more than 3 hrs.) we first tried different ventilation, vasodilatation, and hemodynamic strategies for max. 4 hrs. (inv. I/E ratio, HFOV, epoprostenol, high doses norepinephrine. If the 01 did not decrease by< 10, 30-280 mg natural surfactant or 1-20 ppm nitric oxide were treatment options depending on the degree of pulmonary hypertension measured by echocardiography and by mixed venous saturation measurements. It was possible to use NO and surfactant sequentially. The patients had different etiologies of ARDS as near drowning, pneumonia, immunosuppression, and sepsis. If their 01 did not decrease by 10 in 8 hrs. ECMO was installed. Nineteen patients were evaluated, 6 improved with conventional therapy, their 01 decreased without a relapse (mean 01 at begin of the study: 38). Six patients improved with surfactant therapy alone (mean 01: 54), 4 patients improved after surfactant and sequential NO-treatment, 3 patients were initially treated with NO, 1 sequentially with surfactant. One patient did not show any benefit from NO or surfactant and was put on ECMO. Three patients died (withdrawal of life support because of severe brain damage caused by the underlying disease). We could not observe any respiratory related failure. No patient had to be discharged on oxygen. A sophisticated treatment algorithm integrating different modern ARDS treatment options can reduce the number of patients requiring ECMO. We speculate however that these options can only be used effectively in centers involved in ARDS treatment quite frequently and that these centers have to provide ECMO as one of their therapeutic tools.
Severity and Outcome of ARDS: The Present Place of Extracorporeal Lung Assist (ECLA)
Authors: Steltzer H. , Krafft P. , Fridrich P. , Hammerle A. F.
Published: March 2018

Within the last decade extracorporeal lung assist has been recommended for the treatment of acute respiratory distress syndrome. However, this recommandation was challenged by several recent clinical studies and reviews. The goal of our analysis was therefore to investigate data on outcome and severity of gas exchange disturbance published from patients treated with ECLA. These data were compared to a historical control group consisting of ARDS patients treated conventionally. Computerized (MEDLINE 1967-95) literature search using the keywords ARDS, ECLA, ECMO, ECCO2R and HUMAN was performed. Only clinical studies published as full papers reporting data on both, patients mortality and oxygenation index (PaO2/FiO2) were included. Overall mean mortality reported was 53±22% in 17 studies (419 patients), with no apparent trend towards a higher survival within the last decade with a mean PaO2/FIO2 (14 papers; 61±17 mmHg). However, mean mortality rates of ARDS patients requiring ECLA was 52.3% and 44.9% if patients undergoing ECMO were excluded (3 papers). Therefore the mortality of these patients with severe lung injury was in the range of patients treated conventionally. Patient outcome observed in our analysis is in accordance with the mortality rates from the European ECLA centres published recently (49% in 1993). Therefore, we conclude that the mean mortality rate of patients suffering from severe ARDS treated with ECLA is in the 50% range and does not differ significantly from those of patients treated conventionally, despite significantly poorer pulmonary function.
Reduction of Haemorrhagic Complications during Mechanically Assisted Circulation with the Use of a Multi-System Anticoagulation Protocol
Authors: Glauber M. , Szefner J. , Senni M. , Gamba A. , Mamprin F. , Fiocchi R. , Somaschini M. , Ferrazzi P.
Published: March 2018

Two different anticoagulation protocols were used in 49 consecutive patients mechanically supported either for bridge to transplantation (11) or for recovery of myocardial function after cardiac surgery (35). In 46 patients a Biomedicus centrifugal pump was used and in 3 patients a Pierce-Donachy ventricles. Mechanical support was provided to the left ventricle in 14 patients, to the right ventricle in 6 and to both ventricles in 12 patients; an extra-corporeal membrane oxygenator (ECMO) support was used in 17 patients. Thirty-seven males and 12 females, aged 0.2 to 58 years, were supported for an average time of 6.3 days (range 1-43). Anticoagulation was either based on a continuous infusion of heparin in the first 27 patients (group A) or on a multi-system therapy (“La Pitié” protocol) in the other 22 patients (group B). Overall survival rate was 47%. Patients in group A had a 30% (8/27) survival rate, whereas in group B a 68% (15/22) survival rate was observed (p=0.006). Transplantation and ventricular assist device (VAD) removal was successfully obtained in 59% (16/27) and 91% (20/22) of patients in group A and group B respectively (p=0.05). Significant bleeding occurred in 21 patients (81%) in group A and in 2 (9%) of group B (p=0.001). In these patients bleeding averaged 230 ± 231 ml/kg in group A versus 55 ± 18 ml/kg in group B (p=0.001). Surgical revision was necessary for cardiac tamponade or persistent bleeding in 12 patients of group A (25 procedures: mean 0.9/ patient) and in 3 patients of group B (one each patient: mean 0.1/patient) (p=0.01). Infection, thrombo-embolism and brain hemorrhage were also less frequent in group A than in group B. Our data suggest that the “La Pitié” protocol provides a better control of bleeding than the conventional heparin infusion in patients receiving assist device, this reduction in thrombo-hemorrhagic complications might improve the results of mechanical circulatory support.
Perfluorochemical Liquid Ventilation: From the Animal Laboratory to the Intensive Care Unit
Authors: Degraeuwe P.L.J. , Vos G. D. , Blanco C. E.
Published: March 2018

Perfluorochemical or perfluorocarbon liquids have an enormous gas-carrying capacity. During tidal liquid ventilation the respiratory medium of both functional residual capacity and tidal volume is replaced by neat perfluorocarbon liquid. Tidal liquid ventilation is characterized by convective and diffusive limitations, but offers the advantage of preserved functional residual capacity, high compliance and improved ventilation-perfusion matching. During partial liquid ventilation only the functional residual capacity is replaced by perfluorocarbon liquid. Both tidal and partial liquid ventilation improve gas exchange and lung mechanics in hyaline membrane disease, adult respiratory distress models and meconium aspiration. Compared to gas ventilation, there is less histologic evidence of barotrauma after liquid ventilation. Cardio-pulmonary interaction, inherent to the high density of liquid, and long term safety need further study. However, extrapolating from animal data, and taking into account promising human pilot studies, liquid ventilation has the desired properties to occupy an important place in the therapy of restrictive lung disease in man.
Bioelectrical Impedance and Hemodialysis
Authors: Mandolfo S. , Farina M. , Imbasciati E.
Published: March 2018

Bioimpedance is a simple and non-invasive method of assessing body fluid composition. The aim of our study was to evaluate the reliability of impedance: a) to measure urea distribution volume considered to be coextensive with total body water (TBW); b) to assess the changes in body fluid compartments before and after dialysis; c) to predict hypotensive episodes. In twelve hemodialysis patients, TBW measured by bioelectrical impedance analysis (BIA) before a dialysis session was significantly correlated with the urea distribution volume estimated by dialysis direct quantification (r=0.64, p < 0.05) and with TBW calculated by the Watson equation (r=0.65, p < 0.05). Anthropometric values were, on average, 4.8% higher. TBW measured by BIA at the end of treatment overestimated fluid losses induced by ultrafiltration by 14% to 70%, while TBW 6 h after dialysis reflected the weight losses. On line BIA during hemodialysis has a very low positive predictive value (41.6%) and poor sensitivity (66%) for the prediction of hypotension. In conclusion, BIA is helpful in assessing the urea distribution volume but is not reliable for assessing acute fluid changes nor for predicting hypotensive episodes related to hemodialysis.