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PubMed2002

Efficiency of the glutaraldehyde test strip for monitoring the concentration of glutaraldehyde in reused solutions for disinfecting endoscopes.

BACKGROUND: Glutaraldehyde has been widely used for low-temperature disinfection of endoscopes. The current practice at Siriraj Hospital is to change the glutaraldehyde solution every 21 days or when the solution appears turbid. The disadvantages of this practice include inadequate disinfection of endoscopes if the concentration of glutaraldehyde in a reused solution is insufficient or wasted if the discarded solution is still active. OBJECTIVE: To determine the efficiency of a glutaraldehyde test strip (GTS) in monitoring the amount of glutaraldehyde in a reused solution for disinfecting endoscopes. METHOD: Reused glutaraldehyde solutions for disinfecting bronchoscopes, gastroscopes and colonoscopes were tested for the concentration of glutaraldehyde with a GTS thrice weekly for the first week and then every working day up to 56 days. If the GTS indicated a concentration of glutaraldehyde > or = 1.8 per cent after 21 days, 5 ml of the solution was taken to the laboratory to determine its mycobactericidal activity. RESULTS: All samples of the reused glutaraldehyde solution up to 56 days with a concentration of > or = 1.8 per cent glutaraldehyde on GTS from testings showed mycobactericidal activity. If the glutaraldehyde solution was reused for up to 28, 42 or 56 days, it could save 9,603; 22,813 and 29,415 baht per year respectively for the gastroscopy and colonoscopy units. The corresponding figures were -949; 2,726 and 4,564 baht per year for the bronchoscopy unit. It is estimated that up to 400,000 baht per year could be saved by adopting the strategy of GTS monitoring in all endoscopy units at Siriraj Hospital. CONCLUSION: The current strategy of discarding reused glutaraldehyde solution in the gastroscopy, colonoscopy and bronchoscopy units at Siriraj Hospital may be inappropriate since the reused solution is still mycobactericidal for up to 56 days.

Bronchoscopes↗
PubMed2000

[Evaluation of a new preservation solution for hypothermic heart transplant].

AIM: One of the major problems encountered in heart transplant is the limited cardiac preservation time. The time limit from the moment the donor heart is removed to the transplant itself is 4-6 hours at maximum. Extending the preservation time would therefore provide access to a larger pool of donors, and also permit long-distance (transfrontier) organ transfer. To attain this aim, a number of different cardiac preservation solutions have been proposed and evaluated either clinically or experimentally; however, no consensus has yet been reached by the various heart transplant teams involved. As finding an optimal solution is of major importance, the aim of the present study was therefore to assess the efficacy of several cardiac preservation solutions: the University of Wisconsin solutions (UW-1 and UW-1 + calcium = UW-2), the Saint-Thomas' Hospital solution (STH-1) and a new solution (NS) developed by our laboratory. METHOD: Male Wistar rats (n = 60) were anesthetized by i.m. injection of pentobarbitol, and randomized into six groups, i.e., NS (group I), STH-1 (group II), UW-1 (group III), UW-2 (group IV), saline solution, NaCl (group V), and controls (group VI). All the hearts except those in the control group were preserved by immersion (8 hours, 4 degrees C) in the different solutions (n = 10/group). The hearts were either a) reperfused in Langendorff mode (functional assessment, n = 5/group); or b) frozen (energetic assessment, n = 5/group). RESULTS: The hearts treated with NaCl displayed arrhythmia and a collapsed mean left ventricular pressure throughout the reperfusion period (3.6 +/- 1.3 mmHg) compared to the NS hearts and the control group (97 +/- 2.6 and 122 +/- 1.9 respectively), while the STH-1, UW-1 and UW-2 hearts showed an intermediate-range ventricular function (48 +/- 4; 39.9 +/- 4.1; and 69 +/- 1.8 respectively). Creatine kinase levels were higher in the STH-1 and NaCl groups (541.9 +/- 168 and 1,080.8 +/- 126.2 IU/L respectively). The energetic charge was significantly lower in the NaCl and UW-2 groups (P = 0.001) compared to the control, NS, STH-1 and UW-1 groups. CONCLUSION: It was found that the composition of the respective solutions had a major effect on the the quality of myocardial preservation. Compared to the other solutions tested in this study, the NS solution was found to be optimal for the preservation of isolated hypothermic rat hearts.

Animals↗
PubMedDate not supplied

A randomized clinical trial with a 0.6% amino acid/ 1.4% glycerol peritoneal dialysis solution.

BACKGROUND: Glucose is an accepted osmotic agent for peritoneal dialysis (PD) although it has several drawbacks. Some of these drawbacks have been addressed by the introduction of solutions with low glucose degradation products and physiological pH in dual-chambered bags. Despite this achievement, there is a need for alternative osmotic agents.This randomized clinical trial analyzes 3-month's clinical experience with a mixture of 0.6% amino acids and 1.4% glycerol. METHODS: The study was performed at the renal units of the University Hospitals Ghent, Belgium, and Utrecht, The Netherlands. Stable PD patients were randomized for either protocol A (test solution, n = 5) or protocol B (control regimen, n = 5). In both protocols, there was a run-in phase of 1 month with a dialysis regimen of 2 x 2 L 2.27% glucose solution (Dianeal; Baxter, Nivelles, Belgium), 1 x 2 L Extraneal (Baxter), and 1 x 2 L glucose solution (Dianeal). After this month-long run-in period, patients in group A received during 3 months 2 x 2 L amino acid/glycerol solution, 1 x 2 L Extraneal, and at least 1 x 2 L of a classic glucose solution. RESULTS: Glucose absorption decreased in the test group during the test phase (from 84.2 +/- 8.7 to 11.7 +/- 11.6 g/24 hours, p = 0.001). Dialysate levels of cancer antigen 125 (CA125) increased in the test group, from 17.5 +/- 11.0 to 32.4 +/- 4.6 units/L (p = 0.04), whereas, in the control group, the levels remained stable (15.5 +/- 8.7 and 14.9 +/- 9.8 units/L respectively, p = 0.4). There were no differences in serum urea, serum bicarbonate, serum osmolarity, serum albumin, or parameters related to skin-fold thickness or serum glycerol levels between control and test solutions. No differences were observed in obtained ultrafiltration after a 4-hour dwell with 2.27% glucose or the test solution, both measured at week 4 of the run-in period and week 12 of the test period. CONCLUSION: This study demonstrated that the use of a new 0.6% amino acid/1.4% glycerol-containing dialysis solution is safe and well tolerated. Glucose load was reduced significantly and dialysate CA125 levels improved significantly. Ultrafiltration was comparable with that of a 2.27% glucose solution. All these factors, in combination with the potential nutritional benefits, can contribute to a beneficial impact on the success of the PD technique. Further long-term studies in larger patient groups are warranted to explore the potential of this promising new solution.

Adult↗
PubMed2006

Impact on peritoneal membrane of use of icodextrin-based dialysis solution in peritoneal dialysis patients.

The usefulness of icodextrin-containing peritoneal dialysis (PD) solution for the management of body fluid and blood pressure has been reported. However, icodextrin PD solution is a foreign solution in the body, and the possible induction of intraperitoneal inflammation has been reported. In this study, we investigated at 6-month intervals the influence of icodextrin solution on peritoneal permeability and inflammatory reactions in patients in whom glucose solution had been changed to icodextrin solution for the overnight dwell. We enrolled 9 anuric PD patients (5 men, 4 women) of mean age 58 +/- 5.9 years (range: 45.6-64.8 years) into the study. The patients' mean duration of PD was 61.9 +/- 42 months (range: 6.7-142.5 months). The cause of end-stage renal disease was chronic glomerulonephritis in all patients. For evaluation ofperitoneal permeability, we performed peritoneal equilibration tests (PETs) immediately after an overnight dwell and determined the dialysate-to-plasma ratios of creatinine (D/P Cr), beta2-microglobulin (D/P beta2m), albumin (D/P Alb), immunoglobulin G (D/P IgG), and alpha2-macroglobulin (D/P alpha2m). We also measured interleukin-6 (IL-6) and fibrinogen degradation products (FDPs) in overnight effluent as indices of inflammation and of the fibrinolysis-coagulation system. The evaluation was performed every 6 months for 24 months. The FDPs in effluent increased significantly at 6 months after the change to icodextrin solution, and IL-6 tended to increase. The D/P beta2m, D/P Alb, D/P IgG, and D/P alpha2m all significantly increased in the course of follow-up. In the PETs, the D/P Cr increased slightly, but the change was nonsignificant. At 30 months after the change to icodextrin solution, 1 patient was diagnosed as having a risk of encapsulating peritoneal sclerosis (pre-EPS). In this patient, rapid increases in IL-6, D/P Cr and macromolecular and small molecular D/P by PET were noted after the change to icodextrin solution. Steroids were administered after the diagnosis of pre-EPS, with the result that the IL-6 level rapidly decreased and the D/P Cr and D/P of small molecules and macromolecules slightly decreased. Icodextrin dialysis solution increased peritoneal permeability. Although the cause was unclear, icodextrin may have changed peritoneal reactivity. Long-term use of icodextrin PD solution requires further investigation.

Albumins↗
PubMed1991

Cardioplegia solutions.

The mechanism of action, characteristics and components, dosage and administration, and adverse effects of cardioplegia solution are described. The pharmacist's role in the formulation, preparation, and quality control of cardioplegia solution is also discussed. The use of cardioplegia solution has substantially increased the safety of cardiac surgery. It protects the myocardium by inducing a rapid and complete diastolic arrest, minimizing myocardial energy requirements and preventing ischemic damage during the arrest phase, and minimizing or preventing reperfusion injury once coronary blood flow is restored. Chemical components added to the cardioplegia solution, such as potassium and glucose, are largely responsible for this protective effect. Basic characteristics of cardioplegia solutions include temperature, osmolarity, and pH. Crystalloid solution has traditionally been used as a vehicle for cardioplegia solution; however, laboratory and clinical studies have demonstrated favorable effects of blood-based cardioplegia solution. Single-pass and recirculating delivery systems can be used to administer either crystalloid or blood cardioplegia solutions. Pharmacists can play a major role in the formulation, preparation, distribution, and quality control of cardioplegia solutions; these solutions prevent myocardial injury during the arrest and reperfusion phases of cardiac surgery.

Cardioplegic Solutions↗
PubMed1991

Prolonged hypothermic cardiac storage with University of Wisconsin solution. An assessment with human cell cultures.

Hypothermic storage of cardiac allografts is routinely used for transplantation but is associated with an increased mortality when ischemic times are greater than 4 hours. The ideal storage conditions (solution and temperature) could extend the current limits of cold ischemia. Human endothelial cells and ventricular myocytes were studied to screen various solutions and temperatures for organ preservation. Four solutions (modified Euro-Collins, phosphate-buffered saline, Stanford cardioplegia, and University of Wisconsin) were evaluated. Endothelial cells were evaluated after prolonged hypothermic storage consisting of 0 degree, 4 degrees, and 8 degrees C for 36 hours, and ventricular myocytes were stored at 0 degree and 8 degrees C for 24 hours. Cell viability was determined by morphology (10 dishes per group), and trypan blue exclusion (5 dishes per group) in addition to a cell adhesion assay (endothelial cells 5 dishes per group) and adenine nucleotide analysis with high-performance liquid chromatography techniques (ventricular myocytes 5 dishes per group). Endothelial cell morphology was best preserved by University of Wisconsin solution (p less than 0.001, chi 2) and at 0 degree C (p less than 0.01, chi 2). Endothelial cells stored with University of Wisconsin solution excluded trypan blue better (1.0% +/- 0.5% cells stained, p less than 0.001. Analysis of variance [ANOVA]). Cell adhesion was poorly protected with Stanford cardioplegia (p less than 0.001, ANOVA). Myocyte morphology was preserved best with University of Wisconsin solution at 0 degree C (p less than 0.001, chi 2). According to trypan blue staining, Euro-Collins and University of Wisconsin solutions were superior to Stanford cardioplegia or phosphate-buffered solutions (p less than 0.001, ANOVA). Temperature did not influence the trypan blue results. Adenosine triphosphate was maintained best with University of Wisconsin solution at 0 degree C (p less than 0.01, ANOVA). Myocytes were more sensitive to the effects of prolonged storage compared with endothelial cells by morphologic criteria and trypan blue staining characteristics, irrespective of the shorter preservation times. University of Wisconsin solution was the most effective solution tested. Colder temperatures (0 degree to 4 degrees C) provided better protection than 8 degrees C. Myocytes were more sensitive to prolonged preservation than endothelial cells. Furthermore, the technique used appears helpful as a model of prolonged hypothermic storage and could be expanded to assess other interventions.

Adenosine Diphosphate↗
PubMed1990

Effectiveness of modified University of Wisconsin solution for heart preservation as assessed in heterotopic rat heart transplant model.

A solution developed at the University of Wisconsin is an excellent preservation solution for the kidney, pancreas, and liver. We studied the effectiveness of a modified University of Wisconsin solution, which was made by reversing the sodium and potassium concentrations, in heart preservation. We first examined the relationship between total ischemic time and 1-week graft survival rates using a saline solution as a control preservation solution by transplanting a heart to the neck of test animals. To determine preserved heart viability, we palpated the heart 1 week postoperatively. The 1-week graft survival rates for the various total ischemic times were as follows: less than 1 hour, six of six; 4 hours, five of six; 8 hours, two of six, 12 hours, one of six; and 16 hours, one of six. These results demonstrate a correlation between total ischemic time and survival rate. Then we compared three preservation solutions--glucose-insulin-potassium, Bretschneider's solution, and the modified University of Wisconsin solution--for 16 hours of simple preservation. The 1-week graft survival rates were one of six for glucose-insulin-potassium, two of six for Bretschneider's solution, and five of six for the modified University of Wisconsin solution. The high survival rate for the modified University of Wisconsin solution under adverse conditions indicates its effectiveness in heart preservation.

Animals↗
PubMed1987

Oxygenation of cardioplegic solutions. Potential for the calcium paradox.

Oxygenation of crystalloid cardioplegic solutions is beneficial, yet bicarbonate-containing solutions equilibrated with 100% oxygen become highly alkaline as carbon dioxide is released. In the isolated perfused rat heart fitted with an intraventricular balloon, we recently observed a sustained contraction related to infusion of cardioplegic solution. In the same model, to record these contractions, we studied myocardial preservation by multidose bicarbonate-containing cardioplegic solutions in which first the calcium content and then the pH was varied. An acalcemic cardioplegic solution (Group 1) and the same solution with calcium provided by adding calcium chloride (Group 2) or blood (Group 3) were equilibrated with 100% oxygen. Ionized calcium concentrations were 0, 0.10 +/- 0.06, and 0.11 +/- 0.07 mmol/L and pH values were 8.74 +/- 0.07, 8.54 +/- 0.08, and 8.40 +/- 0.07, all highly alkaline. Hearts were arrested for 2 hours at 8 degrees +/- 2.5 degrees C and reperfused for 1 hour at 37 degrees C. At end-arrest, myocardial adenosine triphosphate was depleted in all three groups, significantly in Groups 2 and 3. In Group 1 the calcium paradox developed upon reperfusion, with contracture (left ventricular end-diastolic pressure = 60 +/- 7 mm Hg), creatine kinase release up to 620 +/- 134 U/L, a profound further decrease in adenosine triphosphate to 1.9 +/- 1.7 nmol/mg dry weight, and either greatly impaired or no functional recovery (17% +/- 10% of prearrest developed pressure). Three hearts in this group released creatine kinase during arrest and did not resume beating during reperfusion. In Groups 2 and 3, the calcium paradox did not occur; functional recovery was 61% +/- 4% and 71% +/- 9% at 5 minutes of reperfusion. In two additional groups (4 and 5), the pH of the acalcemic cardioplegic solution was decreased by equilibration with 2% and 5% carbon dioxide in oxygen to 7.53 +/- 0.03 and 7.11 +/- 0.02. Contractions during arrest were smaller than in Groups 1, 2, and 3; adenosine triphosphate was maintained during arrest; functional recovery was 101% +/- 3% and 96% +/- 4% at 5 minutes of reperfusion. We conclude that acalcemic solutions with carbon dioxide are superior to highly alkaline calcium-containing solutions. If oxygenation of cardioplegic solutions, of proved value, causes severe alkalinity, then calcium paradox may result even with hypothermia. This hazard is prevented by adding calcium or blood to the solution or carbon dioxide to the oxygen used for equilibration.

Adenine Nucleotides↗
PubMed1988

In vitro cyanide release from sodium nitroprusside in various intravenous solutions.

The concentration of cyanide, a toxic metabolite of sodium nitroprusside, in solutions other than 5% dextrose in water, has not been reported. In this study, cyanide ion levels were measured by a cyanide ion-specific electrode in 250 ml of six different intravenous solutions (5% dextrose in water, 10% dextrose in water, distilled water, 0.9% sodium chloride, and lactated Ringer's solution with and without 5% dextrose) exposed to 300 foot candles of fluorescent light for 72 hours after sodium nitroprusside was dissolved in each solution. The rates of the increase in cyanide ion concentration in all six solutions were fairly constant between 4 and 24 hours. At 24 hours, there were no statistically significant differences in cyanide ion concentration among the six solutions. After 24 hours, the rate of the increase in cyanide ion concentration in the electrolyte solutions decreased more than that in the nonelectrolyte solutions. At 72 hours, the electrolyte-containing solutions had statistically significant lower mean cyanide ion concentrations than 5% dextrose, often the recommended diluent for sodium nitroprusside. There was no difference in mean cyanide ion concentration between lactated Ringer's solution with and without 5% dextrose. Solutions containing electrolytes are preferable to 5% dextrose for the dilution of sodium nitroprusside.

Cyanides↗
PubMed1987

Cold storage of the rat heart for transplantation. Two types of solution required for optimal preservation.

Two solutions, our cardioplegic solution and Collins' solution, were tested with regard to preservation of the heart under deep hypothermia before transplantation. The setup used was the isolated perfused working rat heart model and 4 hours of preservation at 0 degree C. The following three groups were prepared: Group 1: the heart was arrested with the cardioplegic solution (potassium: 20 mmol/L, sodium: 87 mmol/L) and then flushed with and stored in Collins' solution (potassium: 117 mmol/L, sodium: 10 mmol/L); Group 2: the heart was arrested with and stored in Collins' solution; and Group 3: the heart was arrested with and stored in the cardioplegic solution. The recovery of cardiac function was more satisfactory in Group 1 than in Groups 2 and 3. The increase in lactate was greater, and adenosine triphosphate and total adenine nucleotide were more depleted during storage in Group 2 than in Groups 1 and 3. In Group 3 myocardial sodium accumulation and potassium depletion during storage were greater than in Groups 1 and 2, and myocardial sodium and calcium overload after reperfusion were greater than in Group 1. Myocardial calcium overload after reperfusion in Group 2 was also greater than that in Group 1. These findings plus coronary vascular resistance analysis revealed that Collins' solution damages the heart during arrest procedures and that the cardioplegic solution is less effective for storage of the arrested heart under deep hypothermia. Therefore the heart should be first arrested with the cardioplegic solution and then flushed with and kept in Collins' solution for simple cold storage.

Animals↗
PubMed1987

Optimal myocardial preservation with an acalcemic crystalloid cardioplegic solution.

The effect of the calcium and oxygen contents of a hyperkalemic glucose-containing cardioplegic solution on myocardial preservation was examined in the isolated working rat heart. The cardioplegic solution was delivered at 4 degrees C every 15 minutes during 2 hours of arrest, maintaining a myocardial temperature of 8 degrees +/- 2 degrees C. Hearts were reperfused in the Langendorff mode for 15 minutes and then resumed the working mode for a further 30 minutes. Groups of hearts were given the oxygenated cardioplegic solution containing an ionized calcium concentration of 0, 0.25, 0.75, or 1.25 mmol/L or the same solution nitrogenated to reduce the oxygen content and containing 0 or 0.75 mmol ionized calcium per liter. The myocardial adenosine triphosphate concentrations at the end of arrest in these six groups of hearts were 15.6 +/- 1.2, 9.5 +/- 0.5, 8.2 +/- 1.1, 4.9 +/- 1.8, 10.1 +/- 2.0, and 1.6 +/- 0.4 nmol/mg dry weight, respectively. At 5 minutes of working reperfusion, the percentages of prearrest aortic flow were 80 +/- 2, 62 +/- 4, 33 +/- 6, 37 +/- 5, 48 +/- 7 and 46 +/- 8, respectively. The differences among the groups in adenosine triphosphate concentrations and in functional recovery diminished during reperfusion. In hearts given the hypoxic calcium-containing solution, there was a marked increase in coronary vascular resistance during the administration of successive doses of cardioplegic solution, which was rapidly reversible upon reperfusion. These data indicate that hearts given the acalcemic oxygenated solution had better adenosine triphosphate preservation during arrest and better functional recovery than hearts in any other group. Addition of calcium to the oxygenated cardioplegic solution decreased adenosine triphosphate preservation and functional recovery. Oxygenation of the acalcemic solution increased adenosine triphosphate preservation and functional recovery. The lowest adenosine triphosphate levels at end arrest were observed in hearts given the hypoxic calcium-containing solution. In the setting of hypothermia and multidose administration, the addition of calcium to a cardioplegic solution resulted in increased energy depletion during arrest and depressed recovery.

Animals↗
PubMed1987

Stability of cefazolin sodium in various artificial tear solutions and aqueous vehicles.

The stability of cefazolin sodium reconstituted in four artificial tear solutions, two acetate buffer solutions, phosphate buffer solution, and 0.9% sodium chloride injection was studied. Cefazolin was reconstituted in Tearisol, Isopto Tears, Liquifilm Forte, and Liquifilm Tears; acetate buffer solution at pH 4.5 and pH 5.7; phosphate buffer solution at pH 7.5; and 0.9% sodium chloride injection. The solutions were stored at 4 degrees C, 25 degrees C, and 35 degrees C for seven days. All of the solutions were inspected for particulates, turbidity, color, and odor. Five assay determinations on each of three samples of each formulation were performed using a stability-indicating high-performance liquid chromatographic assay. Cefazolin stability was influenced primarily by pH and storage temperature. Reconstitution of cefazolin sodium in the alkaline tear solutions Isopto Tears and Tearisol and in phosphate buffer solution resulted in particulate and color formation at 25 degrees C and 35 degrees C. Turbidity was noted after cefazolin sodium was reconstituted in Isopto Tears. No color or precipitate formation was evident after seven days at 25 degrees C and 35 degrees C in the formulations of acidic pH containing Liquifilm Tears, Liquifilm Forte, 0.9% sodium chloride injection or acetate buffer solution as the vehicles. The extent of degradation of cefazolin was substantially higher in the formulations of alkaline pH than in those of acidic pH at 35 degrees C and 25 degrees C. All of the formulations retained more than 90% of their initial concentration when stored at 4 degrees C. Cefazolin sodium, when reconstituted in artificial tear solutions with an acidic pH, is stable for up to three days at room temperature.

Cefazolin↗
PubMed1982

Effect of multidose cardioplegia and cardioplegic solution buffering on myocardial tissue acidosis.

Multidose administration of cardioplegic solution during cardiac operation is intended to maintain both electromechanical arrest of the heart and myocardial hypothermia as well as to remove accumulated metabolites of anaerobic glycolysis. This study was conducted to assess the effect of multidose infusion of three different types of cardioplegic solution on tissue acidosis during global myocardial ischemia. Three groups of five dogs each were placed on cardiopulmonary bypass and the aorta was cross-clamped for 3 hours. The hearts were maintained at a constant temperature (20 degrees C) and cardioplegic solution was infused at an initial dose of 500 ml and five supplementary doses of 250 ml administered every 30 minutes. Group 1 received a crystalloid solution weakly buffered with sodium bicarbonate, Group 2 received a blood-based solution, and Group 3 received a crystalloid solution strongly buffered with histidine (Bretschneider's solution). The buffering capacities of the solutions used in Groups 2 and 3 were 40 and 60 times, respectively, that of the solution used in Group 1. The average myocardial tissue pH at the end of 3 hours of ischemia was 6.54 +/- 0.07 in Group 1, 7.23 +/- 0.05 in Group 2, and 7.19 +/- 0.06 in Group 3 (Group 1 significantly lower than Groups 2 and 3). Multidose infusion of a cardioplegic solution with low buffering capacity was unable to prevent the progressive development of tissue acidosis during 3 hours of ischemia. However, the multidose infusion of either blood-based or crystalloid solutions with high buffering capacity completely prevented any further reduction of tissue pH after the first 30 minutes of ischemia.

Acidosis↗
PubMed1994

Anti-hypertensive effect of low Na connection (120 mEq/l) solution for CAPD patients.

In patients undergoing continuous ambulatory peritoneal dialysis (CAPD), transperitoneal sodium (Na) flux plays a crucial role in the control of blood pressure (BP), as it determines the net Na balance of the patient. However, with the conventional solution, Na removal into the effluent greatly depends on the drained ultrafiltration (UF) volume, and this can hinder the success of adequate Na removal in some patients. Therefore, we developed a low Na concentration solution to increase Na removal through diffusion force, and studied the clinical effect of this solution in patients with Na overload. The composition of the low Na solution is as follows: Na: 120 mEq/l, Ca: 3.5 mEq/l, Mg: 0.5 mEq/l, Cl: 84 mEq/l, lactate: 40 mEq/l, glucose (G) and osmolality: 1.36% (322 mOsm/l) and 2.27% (372 mOsm/l), vol: 2 l. Nine patients (age: 43 +/- 2 yr, oral Na intake: 3.4 +/- 0.3 g/day, mean arterial pressure: 123 +/- 6 mmHg, drained UF volume: 918 +/- 187 ml/day; mean +/- SEM) were studied. Compared to the conventional solution (Na: 132 mEq/l), Na removal using the low Na solution (4 h dwell) was increased from -7.8 +/- 8.7 to -2.3 +/- 5.7 mEq in 1.36% G solution, and from 25.3 +/- 3.1 to 35.4 +/- 4.7 mEq (p < 0.05) in 2.26% G solution. Patients were switched from the conventional solution to the low Na solution, exchanging four times daily for up to 4 weeks. Two patients discontinued low Na solution before the study ended, due to overhydration and hyponatremia, the remaining seven cases showed no adverse symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Improved recovery of heart transplants with a specific kit of preservation solutions.

In the course of cardiac transplantation, donor hearts undergo a four-step sequence of events (arrest, cold storage, global ischemia during implantation, and reperfusion) during which myocardial damage can occur. We tested the hypothesis that the functional recovery of these hearts could be improved by exposure to two interdependently formulated preservation solutions throughout this four-step sequence. Solution I was used as a perfusion and storage medium during the first three steps, and solution II served as a modified reperfusate. The two solutions share the following principles of formulation: prevention of cell swelling (high concentrations of mannitol, a myocardium-specific impermeant) calcium overload (ionic manipulations), and oxidative damage (reduced glutathione) and enhancement of anaerobic energy production (glutamate). The two solutions differ with respect to the calcium content and buffering capacity. One hundred rat hearts perfused with isolated isovolumic buffer were subjected to cardioplegic arrest; cold (2 degrees C) storage for 5 hours, global ischemia at 15 degrees C for 1 hour, and normothermic reperfusion for 1 additional hour. In a first series of experiments (70 hearts), our kit of solutions was compared with six clinical preservation regimens that involved cardiac arrest with St. Thomas' Hospital or University of Wisconsin solutions followed by storage of the hearts in saline, Euro-Collins, St. Thomas' Hospital, or University of Wisconsin solutions. In a second series of experiments (30 hearts), the effects of the kit were more specifically investigated in relation to two types of additive--oncotic agents (dextran) and thiol-based antioxidants (reduced glutathione and N-acetyl-L-cysteine). According to comparisons of maximal rate of ventricular pressure increase and left ventricular compliance after reperfusion, the best myocardial protection was afforded by our kit of solutions. The addition of dextran during storage did not provide additional protection. Conversely, the omission of reduced glutathione was clearly detrimental; the replacement of reduced glutathione with N-acetyl-L-cysteine failed to improve recovery beyond that provided by antioxidant-free solutions, thereby suggesting the importance, in this model, of an anti-free radical compound that, like reduced glutathione, is operative extracellularly. We conclude that the preservation of heart transplants can be improved with the sequential use of two closely interrelated solutions, the formulations of which integrate the basic principles of organ preservation with those of myocardium-specific metabolism.

Animals↗
PubMedDate not supplied

The effect of dialysate acidity on peritoneal solute transport in the rat.

OBJECTIVE: To investigate the possible effect of unphysiologically low pH in dialysis fluid on peritoneal transport. DESIGN: A 4-hour single-cycle experimental session of peritoneal dialysis was performed in six Sprague-Dawley rats using Dianeal 3.86% solution modified by adding 5 mmol/L of sodium hydroxide, neutral pH solution (NpHS) (pH 7.4). The intraperitoneal volume (VD) and peritoneal bulk fluid reabsorption (Qa) were calculated using a marker, 131I-labeled human serum albumin (RISA). The diffusive mass transport coefficient (KBD) as well as sieving coefficient (S) for glucose, urea, sodium, and potassium were calculated using the Babb-Randerson-Farrell model. The same study was performed in seven rats using Dianeal 3.86% solution, acidic pH solution (ApHS) (pH 5.7) to provide control values. RESULTS: The dialysate pH was stable with NpHS; 45 min after the infusion of ApHS it increased rapidly and reached the physiological value 7.4. Dialysate volume and KBD values for sodium and potassium with NpHS were significantly higher than with ApHS, while the KBD values for glucose and urea did not differ between the two solutions. S values for sodium and urea did not differ between the two solutions, while the values for glucose and potassium with NpHS were significantly higher and lower, respectively, than the values with ApHS (0.92 +/- 1.04 vs 0.04 +/- 0.63 and 0.56 +/- 060 vs 1.15 +/- 0.39, p < 0.05). The absorption of glucose from the dialysis solution expressed as a percentage of the initial amount of dialysate glucose was significantly lower with NpHS than with ApHS at 30 min (17.3 +/- 1.7% vs 29.7 +/- 2.0%, p < 0.05). CONCLUSION: We conclude that the peritoneal transport of fluid and small solutes might to some extent be influenced by the acidity of the dialysis solution. The vasodilatory effect of acidic dialysis solution might be the most important mechanism for these differences. However, a larger KBD value and a lower S value for potassium and higher S values for glucose during dialysis with the neutral dialysis solution may indicate that transport mechanisms other than simple passive transport are involved in peritoneal transport for glucose and electrolytes.

Absorption↗
PubMed1996

Effects of different cold preservation solutions on restoration of hepatic energy metabolism during cold reperfusion.

Rat livers were flushed with different preservation solutions and stored at 4 degrees C for 24 h before being reperfused with a synthetic air-equilibrated, water-based solution. Four solutions were tested using this isolated rat liver model: Marshall's hypertonic citrate (HC); modified University of Wisconsin solution (Mod UW); a histidine-based solution (HIS); and a histidine-lactobionate-raffinose-based solution (HLR). After storage, livers were perfused at 4 degrees C for a period of 2 h and biopsy samples taken, at different time points, to investigate energy metabolism. Livers stored in HLR and HIS had higher 24-h storage levels of ATP (0.41 and 0.24 mumol/g respectively; P < 0.05) than those stored in Mod UW and HC. On reperfusion, all groups regenerated ATP by 1-2 h. However, significantly greater levels of ATP regeneration occurred in livers stored in the HLR (1.6 +/- 0.08 mumol/g) and Mod UW (1.3 +/- 0.18) than HC (0.58 +/- 0.19) and HIS (0.96 +/- 0.12); P < 0.05. Energy charge (1) (EC) recovered in all groups but was significantly higher in HLR and Mod UW (0.79 and 0.68, respectively; P < 0.05) than HC and HIS. These represent 95% (HLR) and 80% (Mod UW) of values observed in FIL. During the reperfusion period, total adenine nucleotide levels (TA) did not vary significantly within each storage group, except in the HIS solution. However, TAs were greater with livers stored for 24 h in HLR (2.5 +/- 0.25) and Mod UW (2.7 +/- 0.20) than those the other two storage groups (P < 0.05 in each case). This study has demonstrated that it was possible to resuscitate liver energetics after prolonged hypothermic ischemia by a period of cold reperfusion, and the method can differentiate between preservation solutions. The livers stored in each solution showed varying degrees of success in regeneration of ATP and EC, demonstrating that oxygen was not a limiting factor when using an air-equilibrated perfusate. The solutions providing the better preservation conditions gave the greater resuscitation of liver energetics (Mod UW and HLR). Overall, livers stored in HLR had the greatest resuscitation of energy metabolism, which correlates with survival data from other studies (29-31, 33).

Adenosine↗
PubMed1992

University of Wisconsin solution for pulmonary preservation in a rat transplant model.

University of Wisconsin and modified Euro-Collins solutions for pulmonary preservation were compared in a rat orthotopic left lung isotransplant model. Heart-lung blocks of donor rats were flushed with and preserved in one of the preservation solutions at 0 degrees C. After 6 or 12 hours of cold ischemia, the left lungs were transplanted into recipient rats and reperfused for 1 hour. Pulmonary function was assessed by measuring oxygen and carbon dioxide tensions in arterial blood after removal of the right lung. Lipid peroxide concentrations were measured as thiobarbiturate acid-reactive substances. The ratios of wet to dry weight of grafts after ischemia and after reperfusion were calculated. Histologic changes of ischemia-reperfusion injury of the lung tissue were evaluated using a graded scale. Oxygen tension after 6 hours of preservation followed by reperfusion was significantly higher with University of Wisconsin solution (308.8 +/- 81.1 mm Hg) than with Euro-Collins solution (50.8 +/- 17.8 mm Hg; p less than 0.001). Carbon dioxide tension in the University of Wisconsin solution group was also significantly lower than in the Euro-Collins solution group (28.2 +/- 2.3 versus 46.0 +/- 4.5 mm Hg; p less than 0.05). Lipid peroxide concentration after 6 hours' preservation in University of Wisconsin solution was significantly lower (0.88 +/- 0.07 mumol/g) than that in Euro-Collins solution (1.26 +/- 0.12 mumol/g; p less than 0.05). After 12 hours of preservation only lipid peroxide concentration with University of Wisconsin solution was significantly lower (1.30 +/- 0.09 mumol/g) than with Euro-Collins solution (1.71 +/- 0.15 mumol/g; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

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