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PubMed1999

Comparison of topical application of oxytetracycline and four nonantibiotic solutions for treatment of papillomatous digital dermatitis in dairy cows.

OBJECTIVE: To compare efficacy of topical treatment with oxytetracycline solution or 1 of 4 nonantibiotic solutions among dairy cows with papillomatous digital dermatitis (PDD). DESIGN: Randomized field trial. ANIMALS: 66 cows in a single herd. PROCEDURE: Cows were randomly assigned to be treated with oxytetracycline solution; a commercial formulation of soluble copper, peroxide compound, and a cationic agent; 5% copper sulfate solution; acidified ionized copper solution; hydrogen peroxide-peroxyacetic acid solution; or tap water. Cows were examined 14 and 30 days after initial treatment. During each examination, pain and lesion scores were recorded. RESULTS: On the basis of pain and lesion scores, oxytetracycline and the commercial formulation appeared equally effective for treatment of PDD and significantly more effective than 5% copper sulfate solution, acidified ionized copper solution, hydrogen peroxide-peroxyacetic acid solution, and tap water. Proportions of cows with signs of pain or visible lesions after treatment were significantly lower for cows treated with oxytetracycline or the commercial formulation than for cows in the other groups. CLINICAL IMPLICATIONS: Oxytetracycline and a commercial formulation of soluble copper, peroxide compound, and a cationic agent appeared to be effective for treatment of PDD in dairy cows.

Administration, Topical↗
PubMed1999

Stability of fumagillin in an extemporaneously prepared ophthalmic solution.

The stability of fumagillin 70 microg/mL (as the bicyclohexylammonium crystal) in an extemporaneously prepared ophthalmic solution was studied. An ophthalmic solution of fumagillin 70 microg/mL was prepared by combining 120 mg of fumagillin bicyclohexylammonium crystals with 20 mL of 0.9% Sodium Chloride Injection, USP, and 20 mL of an ophthalmic irrigating solution. The solution was stored in 12 sterile semi-opaque dropper bottles; 4 bottles were stored at 25 degrees C exposed to light, 4 were stored at 25 degrees C in the dark, and 4 were stored at 4 degrees C in the dark. Samples were taken on days 0, 7, 14, 21, and 28 and analyzed by high-performance liquid chromatography. Sterility was tested as well. In the solutions stored at 25 degrees C, 17-30% of the initial drug concentration was lost during the first week. The solution protected from light and stored at 4 degrees C lost about 12% of active drug by week 4. There was no change in color or odor in any of the solutions and only a minor change in pH over the study period. There was no evidence of microbial growth in any of the solutions tested. Fumagillin 70 microg/mL (as the bicyclohexylammonium crystal) in 0.9% sodium chloride injection and an ophthalmic irrigating solution containing benzalkonium chloride was stable in the dark for 14 days at 4 degrees C.

Antiprotozoal Agents↗
PubMed1999

New solutions for peritoneal dialysis in adult and pediatric patients.

The standard PD solutions used today contain physiological electrolyte profiles similar to that of interstitial fluids and are supplemented with glucose as the osmotic agent. Improvements in solution composition during the last 20 years have been largely restricted to minor changes in buffer and electrolyte levels. Newer PD solutions, on the other hand, are designed to manage comorbidities associated with patients on maintenance dialysis, to tailor the ultrafiltration profile based upon dwell time, and to better preserve peritoneal membrane function and host defenses. The evidence to date indicates that, in malnourished PD patients (children and adults), IP amino acids improve protein nutritional status, particularly if low protein intakes are a cause of the malnutrition. The availability of glucose polymers allows the clinician to complement standard glucose-based formulations with one that can provide improved ultrafiltration in both CAPD and APD patients for long dwells, and in patients experiencing ultrafiltration loss owing to a large effective peritoneal surface area. Owing to the reduced calorie and carbohydrate load, glucose polymers may also offer long-term metabolic advantages. Although the control of acid-base balance can be well managed in the vast majority of patients with a 35-40 mmol/L lactate solution, the development and clinical evaluation of bicarbonate-based solutions is underway as a result of concern over the potentially bioincompatible nature of acidic lactate formulations. To date, in vitro, ex vivo, and limited clinical studies show that such formulations, and in particular bicarbonate/lactate combinations are efficacious and well tolerated, and show improved peritoneal cell function versus conventional solutions. In conclusion, ongoing research and development has produced a new generation of PD solutions that, to various degrees, meet different criteria established for an ideal PD solution for chronic adult and pediatric patients on PD. These criteria include good clearance and ultrafiltration, supply of nutrition, iso-osmolality, physiologic pH, bicarbonate buffer, and minimal absorption of the osmotic agent. Several of the new solutions have already demonstrated clinical utility in controlled clinical trials and are commercially available in Europe. Wider clinical use will further add to our understanding of the impact of these formulations on patient outcomes.

Adult↗
PubMed1979

Visual compatibility of 30 additives with a parenteral nutrient solution.

The visual compatibility of 30 drug additives with total parenteral nutrient (TPN) solutions (4.25% amino acids, 25% dextrose injection) was studied. For each drug additive, three TPN solutions were mixed; two were stored for 22 hours at 4 C then allowed to equilibrate to room temperature for two hours. Two 25-ml samples from each TPN solution were examined immediately or after 25 hours for visual appearance, particulate matter levels and pH. A microscope was used to count and measure particles filtered from samples on a 0.8-micrometer filter. Only the TPN solutions containing amphotericin B showed any visual discoloration or precipitation. All amphotericin B samples and the 25-hour ampicillin sodium samples exceeded USP particulate matter specifications. Individual particulate matter levels of the other TPN solutions varied but met USP specifications. With the exception of tetracycline hydrochloride, which dropped the TPN solution's pH 0.9 units, the additives had little effect on pH of the TPN solutions (pH 6.45). Amphotericin B and ampicillin sodium were considered visually incompatible with TPN solutions. All other drug additives tested were visually compatible with TPN solutions.

Drug Combinations↗
PubMed2000

Comparison of University of Wisconsin and St Thomas' Hospital solutions on endothelium-derived hyperpolarizing factor-mediated function in coronary micro-arteries.

BACKGROUND: It is controversial whether coronary endothelial function is impaired after cold exposure to University of Wisconsin (UW) or St. Thomas' Hospital (ST) solution during heart transplantation. We therefore examined the effects of cold storage of coronary micro-arteries with UW or ST solution on endothelium-derived hyperpolarizing factor (EDHF)-mediated function. METHODS: Porcine and human coronary arteries were immersed in either UW or ST solution at 4 degrees C for 4 hr and then normalized in a wire myograph. RESULTS: In the rings (normalized diameter: 200-500 microM) precontracted by U46619, EDHF-mediated relaxation and hyperpolarization were initiated by bradykinin (BK) or A23187 in the presence of indomethacin and NG-nitro-L-arginine. In the human coronary arteries, the EDHF-mediated relaxation to BK was reduced by UW solution from 53.2+/-5.6% to 24.0+/-2.7% (P=0.006). The reduced EDHF-mediated relaxation occurred concurrently with the decreased hyperpolarization to BK (17.0+/-1.5 vs. 10.5+/-1.1 mV, n=10, P=0.004) or A23187 in porcine coronary arteries. In the control arteries, K+ channel blockers, either glybenclamide or tetraethylammonium reduced the EDHF-mediated relaxation. After exposure to UW solution, the EDHF-mediated relaxation was further significantly inhibited. In contrast, ST solution did not affect these responses. CONCLUSIONS: These results show that in coronary micro-arteries, UW, but not ST, solution impairs the EDHF-mediated function and inhibits the Ca2+-activated and ATP-sensitive K+ channels. Our comparative study suggests that ST solution may be superior to UW solution in preserving the EDHF-related endothelial function of coronary micro-arteries.

Adenosine↗
PubMed2001

[Comparative effects of oral rehydratation solutions in experimental cholera in the rat].

UNLABELLED: The composition of the World Health Organisation (WHO) solution in oral rehydration therapy has remained controversial because of its total osmolarity (303 mosm/L) and higher sodium concentration (90 mEq/L), increasing the risk of hypernatraemia. AIM OF THE STUDY: To compare the efficacy of two reduced-osmolarity oral rehydration solutions (S1: 268 mosm/L and 50 mEq/L Na(+); S2: 240 mosm/L and 60 mEq/L Na(+) ) with the WHO recommended formula taken as the reference solution. Water, electrolytes and glucose fluxes were directly measured in vivo, in isolated ligated loops of rat jejunum (n=12). Intestinal secretion was induced by exposing jejunum to cholera toxin (CT=20 microg/loop). RESULTS: All three test solutions similarly reversed cholera toxin-induced net water absorption (3.37 +/- 1.35; 3.31 +/- 0.43 and 3.13 +/- 0.66 microL/min.cm(2) for S1, S2 and WHO solutions respectively). However, net Na secretion induced by cholera toxin was observed with S1 and S2 while Na absorption occurred with the WHO solution. CONCLUSION: For a same amount of water absorbed, Na absorption from reduced - osmolarity rehydration solutions is lower than with the WHO solution. Our data may contribute to a better rationale for the use of orally administered hydration solutions in man.

Animals↗
PubMed2001

Color stability of glass-ionomers and polyacid-modified resin-based composites in various environmental solutions.

PURPOSE: To evaluate the degree of color stability of glass-ionomers (GIs) and polyacid modified resin-based composites (PMRBCs) in various environmental solutions. MATERIALS AND METHODS: Seven polyacid-based esthetic restorative materials were used: three chemical-cured GIs, one resin-modified GI and three polyacid-modified RBCs. A light-cured resin-based composite (RBC) (Z 100) was used as a control. Disk type specimens were prepared and were aged in four different solutions (deionized water, 0.1 mole acetic acid solution, 75% ethanol, and 10% hydrogen peroxide solution) for 1, 7, 14, 21, 28, and 56 days. The specimens were kept at 37 degrees C throughout the study. Color coefficients (CIE L*a*b*) were measured by a reflection spectrophotometer with SCE mode, and the surface of specimens was examined by a stereo zoom microscope. RESULTS: In deionized water, all specimens showed an acceptable color stability. All of the GIs and PMRBCs showed significant color change in 0.1 mole acetic acid solution. The light-cured resin-modified GI showed a significant color change in 75% ethanol solutions. 10% hydrogen peroxide solution resulted in degradation and a high degree of color change for chemical-cured GIs. The light-cured resin-modified GI and PMRBCs showed high color change in 10% hydrogen peroxide solution. The light-cured RBC (Control), showed excellent color stability in all experimental solutions.

Acetic Acid↗
PubMed2002

Solute transport across the peritoneal membrane.

The current understanding of the transport pathways that govern solute removal during peritoneal dialysis is reviewed. Diffusive transport rates across the peritoneal membrane for small solutes are slow. Even though the rate of diffusive solute transport decreases with increasing molecular size, large molecules (e.g., albumin) are nevertheless removed from the patient during routine peritoneal dialysis. Recent work has confirmed a previous suggestion that diffusive solute transport is limited by the small area of the peritoneal membrane that participates in the transport process. This small functional area is due to either poor contact of the peritoneal membrane with dialysis solution bathing the peritoneal cavity or to the limited surface area of capillaries that perfuse peritoneal tissues. Convective solute transport during peritoneal dialysis is proportional to the transperitoneal ultrafiltration rate but is less than that expected, because of low solute sieving by the peritoneal membrane and fluid absorption from the peritoneal cavity. Low solute sieving across the peritoneal membrane was first identified in 1966, a phenomenon that is now attributed to the presence of water-only transport pathways mediated by aquaporin-1. Fluid absorption from the peritoneal cavity occurs at the same time as transperitoneal ultrafiltration, but the pathways by which these two processes occur simultaneously remain speculative. This review proposes a novel hypothesis, whereby fluid absorption occurs in areas of the peritoneal membrane that are governed by different physical forces than those governing transperitoneal ultrafiltration. Further understanding of the pathways for fluid and solute transport during peritoneal dialysis will permit improvements in the adequacy of the dialysis dose and the more efficacious use of peritoneal dialysis to treat patients with end-stage renal disease.

Dialysis Solutions↗
PubMed1975

Nuclear magnetic resonance investigation of the state of water in protein solution.

The line width of the NMR signal of water protons in solutions of native actomyosin and actomyosin denatured by heat, acetone or urea was measured over the temperature range from -10 degrees to below the freezing point. The line widths of the water band which increased exponentially with decreasing temperature were compared with each other and also with those of the corresponding control solution without actomyosin. The line broadening observed for native actomyosin solution on lowering the temperature was significantly smaller than that for heat-denatured actomyosin solution. This difference implies that this signal is sensitive to conformational perturbations of the protein. In addition, the temperature dependence of the line width for heat-, acetone-, or urea-denatured actomyosin solution was similar to that for the corresponding control solution. These phenomena can be interpreted in terms of the state of water associated with the hydrophobic and hydrophilic residues. Similar NMR studies of actomyosin solution containing dimethyl sulfoxide (DMSO) or dimethylformamide (DMF) showed that DMSO and DMF prevent the formation of ice crystals until about -70 degrees, suggesting that the cryoprotective effects of DMSO and DMF are due to the change in the state of water described above. These differences in temperature dependence between the sample and control solutions are well-correlated with the viscosity of the solution. This correlation is useful for elucidation of the mechanism of the protein denaturation.

Acetone↗
PubMedDate not supplied

Continuous flow peritoneal dialysis: assessment of fluid and solute removal in a high-flow model of "fresh dialysate single pass".

BACKGROUND: Growing concern over the limited capacity of the peritoneal dialysis (PD) system has revived interest in continuous flow peritoneal dialysis (CFPD), a modality in which continuous circulation of PD fluid is maintained at a high flow rate using two separate catheters or one dual-lumen catheter. The CFPD regimen contrasts the "inflow/outflow" regimen, which requires specific times devoted to filling and draining the peritoneum via a single-lumen catheter. Historical data established CFPD capabilities in providing higher solute clearance and ultrafiltration rate (UFR) using either an open loop system with a single pass of fresh PD fluid, or various external purifications of the spent dialysate. OBJECTIVE: To compare, in patients with various peritoneal transport patterns, fluid and solute removal achieved during a standardized program of CFPD versus two control schedules: nightly intermittent peritoneal dialysis (NIPD) and nightly tidal peritoneal dialysis (NTPD). This study focused on small solute clearances and UFR using only isotonic PD solution (Dianeal PD1 1.36%; Baxter Healthcare, Castlebar, Ireland). The model of fresh dialysate, single pass, was used to optimize solute gradients and to characterize the impact of a continuous flow regimen on peritoneal transport characteristics. METHODS: In a crossover trial, 4-hour CFPD sessions were performed at a fixed dialysate flow rate (100 mL/ minute) in 5 patients being treated with automated PD. A hemofiltration monitor (BM25; Baxter Healthcare, Brussels, Belgium) was adapted to the CFPD technique. The peritoneal cavity was filled through a temporary second catheter and simultaneously drained using the permanent peritoneal access. Fluid and solute removal were compared to data obtained from a control period based on 8-hour sessions of NIPD or NTPD using 13 L of isotonic dialysate. RESULTS: High-flow CFPD enhanced the diffusive transport coefficient compared with the alternative flow regimen in patients ranging from low to high transporters. Weekly creatinine clearance increased from 36.9 L (22.3 - 49.6 L) and 37.3 L (27.5 - 45.0 L) with NIPD and NTPD respectively, to 74.9 L (42.3 - 107.5 L) with CFPD. Mean UFR was 2.44 mL/min with CFPD versus 0.92 and 0.89 mL/min with NIPD and NTPD respectively. The mass transfer area coefficient (MTAC) of creatinine with CFPD was 2.5-fold that obtained from the peritoneal equilibration test data. CONCLUSION: Our results confirm that CFPD is highly effective in increasing fluid and solute removal. Furthermore, consistent with historical data, our findings indicate that the enhanced solute transfer is not due only to steeper solute gradients, but also depends on increased MTAC in a wide range of peritoneum transport characteristics.

Biological Transport↗
PubMed1992

Overview of the corneal toxicity of surgical solutions and drugs: and clinical concepts in corneal edema.

Surgical solutions and drugs are important in ocular surgery. These include irrigating solutions, viscoelastic substances, mydriatics and miotics, and a growing number of other agents designed to enhance intraocular surgery and its outcome. Potential for damage to the corneal endothelium and other tissues is related to the chemical composition, pH, and osmolality of the irrigating solutions that bathe tissues. Quality balanced salt solutions (BSS) are usually safe for use as an intraocular solution in patients with normal corneal endothelium. If prolonged irrigation times are expected, or the patient already has decompensated endothelium, i.e., primary or secondary endotheliopathy, the use of a "complete" BSS solution is indicated to minimize damage. Intraocular sulfite-containing epinephrine may cause severe corneal edema and should be avoided, or if used, be well diluted. Sulfite-free epinephrine solution is now available and does not cause the endothelial toxicity that one may see with sulfite-containing epinephrine solutions. Current formulations of acetylcholine and carbachol used as miotics in surgery have been evaluated in humans and caution is recommended in using acetylcholine solutions intracamerally in patients with already decompensated endothelium. Chondroitin sulfate, hydroxypropyl methylcellulose, and sodium hyaluronate are non-toxic to animal endothelial cells under conditions analogous to cataract extraction in humans but can be toxic to endothelium if there is continued contact with endothelium for hours. Chondroitin sulfate has been shown to have more of a protective effect in mechanical pseudophakos trauma probably because of its cohesiveness and tendency to coat the endothelium. Viscoelastics cause a significant rise in intraocular pressure of > 30 mm Hg in 3-10% of patients. Very high intraocular pressures are often seen postoperatively after viscoelastic use surgically in patients who preoperatively have a history of ocular hypertension or glaucoma.

Cell Count↗
PubMedDate not supplied

[The causes of the biological action of electrochemically activated solutions by changes in the growth of Escherichia coli cells].

To study the causes of the biological effect of electrochemically activated solutions, nutrient growth media M 9 were prepared using catholyte and anolyte solutions containing separate components of the nutrient medium, such as distilled water, phosphate buffer, phosphate buffer with chlorides (NaCl, NH4Cl), and chlorides. The biological activity of different nutrient media was assessed by a comparison with the stimulation or inhibition of the growth of Escherichia coli cells in the catholyte and anolyte of the complete nutrient medium M 9. It was shown that medium M 9 prepared on the catholytes of different initial solutions acquired the stimulating properties only if the initial solution contained salts containing chlorine. The stimulating effect of the initial solution was 18-24%. Electrochemical treatment of solutions containing no chlorides (distilled water, phosphate buffer) and subsequent addition of the components of nutrient medium to exposed solutions had neither a stimulating nor the inhibiting effect on cell growth. The cultivation of cells in a nutrient medium based on the catholyte of preliminarily treated hydrochloric acid showed that it is the presence of chlorine ions in solution during electrolysis that causes the stimulating effect of the nutrient medium based on the catholyte. The formation of oxidizers and the inhibitory effect of the anolyte described previously was also observed if the solution contained chlorine ions during electrolysis. Possible mechanisms of the biological effect of catholytes containing chlorides during electrolysis were discussed.

Chlorides↗
PubMed1992

Reducing waste of intravenous solutions.

A program to minimize the waste of i.v. drug solutions is outlined, and the results of audits to determine the effectiveness of the program are presented. The program for reducing i.v. solution waste at a 500-bed acute-care center involves measures to compound admixtures for individual shifts, recycle solutions, remove unused solutions from nursing units, use a standardized administration schedule and automatic stop orders, standardize total parenteral nutrient (TPN) solutions, use commercially prepared products when possible, verify telephone orders, and prepare labile products just before use. From January 1987 to January 1990, six 30-day audits were performed to determine the number of i.v. admixtures discarded. The audits showed the hospital's average rate of waste to be 3.27%, well below other published values. The medical and surgical intensive-care units, pediatrics wards, and general medicine units accounted for most of the waste, which was largely attributable to dosage changes and stat-type drugs ordered but never used. Poor communication between the pharmacy and the nursing units also contributed to sterile product waste. Although the audits showed that waste was already at a low level, they pointed out areas for further improvement. A computer linkup that gives physicians the formulas for i.v. solutions is being set up, the list of standardized TPN solution formulas is being expanded to include condition-specific solutions, and clinical pharmacists are establishing better communication with the nursing units. By using several methods to reduce the waste of i.v. solutions, a pharmacy department has limited the rate of waste to only 3.27%.

Appointments and Schedules↗
PubMed2005

Effect of icodextrin-based peritoneal dialysis solution on peritoneal membrane.

Using changes in cell counts and levels of cancer antigen 125 (CA125), fibrinogen degradation product (FDP), and interleukin-6 (IL-6) in effluent before and after the use of icodextrin-based peritoneal dialysis solution (icodextrin), we evaluated the effects of icodextrin on peritoneal membrane. The subjects were 8 anuric patients (4 men, 4 women) who had been using a 2.5% glucose-based dialysis solution (glucose solution) for the overnight dwell. The mean age of the patients was 57.9 +/- 6.1 years, and their mean duration of continuous ambulatory peritoneal dialysis was 61.6 +/- 44.3 months. In all patients, chronic glomerulonephritis was the cause of end-stage renal disease. We changed the 2.5% glucose solution used for the 8-hour dwell to an icodextrin, and we compared cell counts in effluent and levels of IL-6, FDP, and CA125 in the overnight effluent before, and 12 and 36 weeks after, the switch to the icodextrin. When 2.5% glucose solution was used for the overnight 8-hour dwell, the mean cell count in the effluent was 5.5 +/- 3 cells/mm3. However, 12 and 36 weeks after the start of icodextrin, mean cell counts in effluent were significantly increased to 15.3 +/- 7.7 cells/mm3 (p < 0.01) and 16.5 +/- 11.2 cells/mm3 (p < 0.01) respectively. Values of effluent CA125, FDP, and IL-6 obtained during the use of a glucose solution were compared to values obtained 12 and 36 weeks after the start of icodextrin. Effluent levels of CA125 and IL-6 did not vary before and after the use of the icodextrin, but levels of FDP in the icodextrin effluent were higher than the levels found in the effluent of a 2.5% glucose solution (7278.8 +/- 2915 ng/mL before the start of icodextrin; 29,875 +/- 13,227 ng/mL 12 weeks after icodextrin introduction, p < 0.01; and 12,062.9 +/- 5684.6 ng/mL 36 weeks after icodextrin introduction). Icodextrin induced a subclinical inflammatory response in the peritoneum. Therefore, biocompatibility of an icodextrin solution is not always superior to that of a glucose solution, and further research is needed to clarify the influence of long-term icodextrin use on the peritoneum.

Anuria↗
PubMed1991

Stability of cefazolin sodium in peritoneal dialysis solutions.

The stability of cefazolin sodium was studied in two commonly used peritoneal dialysis solutions. Cefazolin (as the sodium salt) 250 mg was added to 500-mL bags of dialysis solution containing 1.5% or 4.25% dextrose injection to yield a target concentration of 0.5 mg/mL. Of 18 bags containing 1.5% dextrose injection, six were stored at 4 degrees C, six at 25 degrees C, and six at 37 degrees C. Similarly, of 18 bags containing 4.25% dextrose injection, groups of six were stored at each temperature. Samples were measured for cefazolin concentration by high-performance liquid chromatography at 0, 3, 7, 10, and 14 days for solutions stored at 4 degrees C; 0, 1, 2, 3, 8, and 11 days for solutions stored at 25 degrees C; and 0, 6, 12, and 24 hours for solutions stored at 37 degrees C. The cefazolin concentration in both solutions was greater than or equal to 90% of the initial concentration for 14 days at 4 degrees C, 8 days at 25 degrees C, and 1 day at 37 degrees C. On day 11 at 25 degrees C, however, the loss of cefazolin was 11% for the solution containing 1.5% dextrose injection and 15% for the 4.25% dextrose injection. The sterility of the solutions was not determined. Cefazolin sodium was stable in peritoneal dialysis solutions containing 1.5% and 4.24% dextrose injection for 14 days at 4 degrees C, 8 days at 25 degrees C, and 24 hours at 37 degrees C.

Cefazolin↗
PubMed1991

Linear gastric emptying of hyperosmolar glucose solutions.

We performed a total of 12 gastric emptying studies on 6 normal subjects with a hyperosmolar (1.85 mol/l) 400-kcal glucose solution commonly used for diagnosing diabetes and a more dilute (0.62 mol/l) 200-kcal glucose solution. The gastric half-emptying time was greatly prolonged with both glucose solutions; 107 min for the (1.85 mol/l) 400-kcal glucose solution compared to 66 min for the more dilute (0.62 mol/l) 200-kcal glucose solution. Although the 200-kcal glucose solution contained one-half the amount of glucose (50 g) compared to the 400-kcal solution (100 g), the blood glucose values obtained during a 2-hr period were only slightly lower with the former solution. This study demonstrates significantly delayed gastric emptying of glucose solutions in normal subjects and a linear pattern of gastric emptying formerly associated only with solid meals.

Administration, Oral↗
PubMed1991

An assessment of crystalloid solutions for donor heart preservation.

The optimal technique for donor heart protection remains controversial. One component of preservation is the transport solution. Although saline solution is most frequently used as a transport medium, other crystalloid solutions may be superior. Accordingly, human right atrial trabeculae contracting isometrically in vitro were used to assess five crystalloid solutions at two different temperatures (12 degrees and 4 degrees C): St. Thomas' Hospital solution, modified Krebs-Henseleit (K+ = 16 mEq/L), Krebs-Henseleit (K+ = 4.5 mEq/L, saline, and Euro-Collins. After a 24-hour preservation period the muscles were restimulated at 34 degrees C and recovery of function was monitored for 30 minutes. Recovery of developed force was not affected by temperature (p = 0.13 by two-way analysis of variance). However, St. Thomas' Hospital solution provided the best recovery of developed force (103.3 +/- 6.2% of control) compared with saline, which had the worst developed force (2.8% +/- 1.3%) (p less than 0.002). Modified Krebs-Henseleit, Krebs-Henseleit, and Euro-Collins demonstrated intermediate performance. Although there were no differences between groups in recovery of resting force, it was greater in all groups with muscles cooled to 4 degrees C (238.7% +/- 17.6% of control) (p less than 0.001). Dry/wet weight ratios did not demonstrate statistically significant differences between groups. We conclude that, of the solutions tested, St. Thomas' Hospital solution provides the best preservation of atrial myocardium. Storage in crystalloid solutions leads to impaired relaxation, which is more apparent in tissue cooled to 4 degrees C and does not appear to be solely due to increased tissue swelling.

Evaluation Studies as Topic↗
PubMed1989

Distribution of cardioplegic solution infused antegradely and retrogradely in normal canine hearts.

The adequacy of retrograde delivery of cardioplegic solution to the right ventricle and interventricular septum is controversial. To address this issue quantitatively, we infused blood cardioplegic solution labeled with radioactive microspheres (15 microns diameter) into the coronary sinus (n = 8 dogs) at a pressure of 51 +/- 1 mm Hg (mean +/- standard error of the mean) to be compared with the same quantity of labeled cardioplegic solution (20 ml/kg) delivered through the aorta (n = 6 dogs) at 97 +/- 7 mm Hg. Both methods of delivery produced cardiac arrest, but retrograde infusion required a significantly longer time to complete the infusion (6.2 +/- 0.8 minutes versus 1.5 +/- 0.1 minutes, p less than 0.01). Greater than 99% of the microspheres passing through the vasculature of the left ventricle were trapped in the left ventricular myocardium with antegrade infusion, and the distribution of the cardioplegic solution was uniform. Antegrade delivery (cardioplegic flow x infusion time) averaged approximately 3.0 to 4.0 ml/gm, except at the apex, where delivery averaged approximately 2.0 ml/gm. With retrograde infusion, 93% of the microspheres perfusing the left ventricle were trapped and delivery of the cardioplegic solution was not uniform. In the anterolateral free wall, delivery of cardioplegic solution averaged between 1.5 and 2.9 ml/gm (p less than 0.001 compared with antegrade) and only 0.6 to 0.8 ml/gm in the posteroseptal region of the basal left ventricle (p less than 0.001 compared with the antegrade group and anterolateral samples of the retrograde group). In the middle portion of the right ventricle, antegrade trapping of microspheres was 99% and delivery of cardioplegic solution averaged approximately 2.0 ml/gm. With retrograde delivery, only 16.5% (range 11.8% to 26.0%) of the microspheres passing through the right ventricular vasculature were trapped in the right ventricular myocardium, which indicates that substantial shunting had occurred. Corrected for the high shunt fraction, retrograde delivery of cardioplegic solution to the middle portion of the right ventricle averaged only 0.5 ml/gm (p less than 0.01). Retrograde delivery to the atrial septum and right atrium was also low. Because retrograde delivery of cardioplegic solution was markedly nonuniform, we conclude that inadequate cardioplegic delivery to the middle portion of the right ventricle and posteroseptal portion of the left ventricle could result with cardioplegic infusion through the coronary sinus.

Animals↗