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O Carlsson

Publications and source records attributed to O Carlsson.

At least 19 recordsLinked to original sources
PubMed2002

The effects of platelet apheresis in total hip replacement surgery on platelet activation.

BACKGROUND: Autologous platelet rich plasma (PRP) harvest with autotransfusion devices has been used for 10 years in cardiac surgery and recently in orthopedics as a blood saving method. The quality of the harvested platelets has not been adequately examined, in part because of methodological difficulties in studying platelet function during surgery. METHODS: Twenty patients undergoing primary total hip replacement (THR) were studied. Ten patients underwent an immediate preoperative platelet apheresis to obtain concentrated platelet rich plasma (c-PRP). The other 10 patients not undergoing apheresis were allocated to a control group. Platelet activation was evaluated as the population expressing P-selectin on the surface of platelets in the c-PRP and in blood samples collected pre-, per- and postoperatively. The method used was flow cytometry. RESULTS AND CONCLUSIONS: A minor population of activated platelets was found to be circulating in the patients' blood, with a highly significant difference between patients (P = 0.005), and with a range of 1-23% in peroperative activation. PRP harvest did not significantly alter platelet activity. The platelet apheresis procedure did not inhibit platelet function in the c-PRP, as judged by a high proportion of platelets that could be activated in ADP stimulation experiments (mean value +/- SD 86% +/- 7.5%).

Adenosine Diphosphate↗
PubMed2001

Hyaluronan and peritoneal ultrafiltration: a test of the "filter-cake" hypothesis.

Adding hyaluronan (HA) to the dialysis fluid seems to improve the efficiency of peritoneal dialysis (PD). This effect may be explained by the gradual formation of a HA "filter-cake" that decreases the tissue hydraulic conductivity. A filter cake (concentration hyperpolarization layer) can be formed when a large, slowly diffusible molecule, such as HA, is partly sieved by the pores of a membrane during the process of transmembrane ultrafiltration. The filter cake then forms at the "uphill" membrane-fluid interface, thereby increasing the resistance to fluid flow across the membrane. To test the filter-cake hypothesis, we investigated the effects of intraperitoneal (IP) HA on peritoneal small solute and water transport by administering HA either during the dwells or as incubations before PD dwells in rats. In the first set of experiments, HA, 0.01% (n = 7), 0.05% (n = 6), and 0.1% (n = 7) was given in 20 mL dialysis fluid (3.86% Dianeal). Control group was instilled with 20 mL of dialysis fluid. Evans Blue (EB) albumin was given as an intra-arterial (IA) bolus and (51)Cr-EDTA as an intravenous (IV) infusion. Plasma and dialysate were sampled up to 240 minutes to determine total peritoneal clearance (Cl), clearance from dialysate to plasma (Cl-->P) of (125)I-albumin (RISA), clearance from plasma to dialysate (Cl-->D) of EB-albumin, and mass transfer area coefficients (MTAC or permeability-surface area products, PS) of (51)Cr-EDTA and glucose. Peritoneal ultrafiltration (UF) was determined from RISA dilution. In the second set of experiments, rats were first incubated with 4 mL of phosphate-buffered saline (PBS) or PBS containing 0.1% HA for 120 minutes. Rats were then dialyzed with HA-free PD fluid, and sampling of plasma and dialysate was performed for 60 minutes. For HA concentrations exceeding 0.01%, UF volumes increased with increasing doses of HA. Small solute MTACs and initial UF were unaffected when HA was either given during the dwell or as a preincubation. Compared with control, there was a significant decrease in RISA-Cl for 0.05% HA and 0.1% HA. Also, Cl-->P decreased significantly compared with control for 0.1% HA. In conclusion, the present data clearly demonstrate that small solute MTACs and the glucose-induced osmotic water transport occurring early in the dwell are not affected by HA. Only the back-filtration of fluid from peritoneum to plasma was affected.

Animals↗
PubMed2001

Transcytosis inhibitor N-ethylmaleimide increases microvascular permeability in rat muscle.

N-ethylmaleimide (NEM) has been claimed to markedly inhibit the transvascular passage of small proteins and albumin by interacting with the docking and fusion of plasmalemmal vesicles with their target membranes. To investigate the role of transcytosis in the transcapillary passage of albumin, we assessed the effects of NEM on (125)I-labeled radioiodinated serum albumin clearance (RISA-Cl) from blood to muscle in isolated and maximally vasodilated perfused rat hindquarters, in which vascular pressures, pre- and postcapillary resistances, and the capillary filtration coefficient (CFC) were continuously monitored. NEM (0.3-0.5 mM) caused a marked increase mainly in precapillary vascular resistance. Thus the arterial-to-venous resistance ratio in NEM-treated animals was 3.12 +/- 0.56 versus 1.66 +/- 0.17 during the control period (P < 0.05). Despite that, there was a doubling of both CFC from 0.0363 +/- 0.0028 to 0.0778 +/- 0.0101 ml x min(-1) x mmHg(-1) x 100 g(-1) (P < 0.01) and RISA-Cl, compared with the control situation, signaling markedly increased microvascular permeability. Our results strongly suggest that NEM, besides producing marked vasoconstriction, also causes damage to the capillary endothelium. Thus, instead of inhibiting transvascular transport, NEM may induce increases in the bulk transport of albumin from blood to tissue.

Animals↗
PubMed2000

Preoperative platelet-rich plasmapheresis and hemodilution with an autotransfusion device in total hip replacement surgery.

The effectiveness of both preoperative autologous donation (PAD) and intraoperative autotransfusion (IAT) with an autotransfusion device has recently been questioned. Preoperative apheresis, with separation of concentrated platelet rich-plasma (c-PRP) and erythrocyte concentrate (ERC), represents an aggressive use of the autotransfusion device. Can such a procedure replace PAD in total hip replacement surgery (THR)? Eighty patients undergoing THR were investigated in a prospective and randomized study. Forty patients underwent PAD, and 2 units of ERC + plasma were retrieved within 4 weeks preoperatively. Another 40 patients underwent an immediately preoperative apheresis with a concomitant hemodilution with 4% albumin, retrieving c-PRP (30% of the platelet pool) and 2 units of ERC. Both groups used IAT up to 2 hours postoperatively, with 3% dextran-60 as a plasma substitute according to our standard of care. There were no differences in blood loss, B-hemoglobin or allogeneic transfusions between the groups: 85% of the patients did not receive allogeneic blood. Both apheresis and reinfusion of c-PRP had minor impact on the coagulation parameters. Platelet count increased slightly but significantly (P<0.05) from 154 to 179 x 10(9)/L after the c-PRP at wound closure. Preoperative apheresis with an autotransfusion device, separating platelet-rich plasma and erythrocyte concentrate, is a useful alternative for patients who are unable to utilize the PAD technique for either religious or practical reasons.

Aged↗
PubMed2000

Effects of peritoneal hyaluronidase treatment on transperitoneal solute and fluid transport in the rat.

The importance of the interstitium and its major ground substance component, hyaluronan (HA), for solute and fluid transport across the peritoneal membrane has been debated during the last few years. We therefore partly removed HA from the peritoneal membrane using enzymatic digestion with hyaluronidase for 2 h, after which the transport properties of the peritoneal membrane were studied in peritoneal dialysis dwells. A dialysis fluid containing 3.86% glucose was used. As a marker of macromolecular transport, the total peritoneal clearance of radiolabelled albumin out of the peritoneal cavity and its clearance to plasma were measured, as well as the albumin clearance from plasma to dialysate. Transport of small solutes between plasma and dialysate was measured by assessing the mass transfer area coefficient of 51Cr-EDTA and glucose. Hyaluronidase preincubation yielded a 78% reduction of HA in the superficial layer of the peritoneal membrane, without alterations in the transport of either small or large solutes compared with the situation in preincubated controls. The only changes observed were between rats incubated with either hyaluronidase or vehicle alone compared to non-incubated controls. In conclusion, despite a large reduction of the HA content of the tissues surrounding the peritoneal cavity, hyaluronidase incubation did not produce any significant changes in solute and fluid transport across the peritoneal membrane. Our data indicate that peritoneal membrane HA in physiological concentrations plays a rather subordinate role in the overall transport of small solutes and water across the capillary-interstitial peritoneal barrier.

Albumins↗
PubMed2000

Tranexamic acid reduces blood loss in total hip replacement surgery.

UNLABELLED: Intraoperatively administered, tranexamic acid (TA) does not reduce bleeding in total hip replacement (THR). Therefore, its prophylactic use was attempted in the present study because this has been shown to be more effective in cardiac surgery. We investigated 40 patients undergoing THR in a prospective, randomized, double-blinded study. Twenty patients received TA given in two bolus doses of 10 mg/kg each, the first just before surgical incision and the second 3 h later. In addition, a continuous infusion of TA, 1.0 mg. kg(-1). h(-1) for 10 h, was given after the first bolus dose. The remaining 20 patients formed a control group. Both groups used preoperative autologous blood donation and intraoperative autotransfusion. Intraoperative bleeding was significantly less (P: = 0.001) in the TA group compared with the control group (630 +/- 220 mL vs 850 +/- 260 mL). Postoperative drainage bleeding was correspondingly less (P: = 0.001) (520 +/- 280 vs 920 +/- 410 mL). Up to 10 h postoperatively, plasma D-dimer concentration was halved in the TA group compared with the control group. One patient in each group had an ultrasound-verified late deep vein thrombosis. In conclusion, we found TA, administrated before surgical incision, to be efficient in reducing bleeding during THR. IMPLICATIONS: In a prospective, double-blinded study of 40 patients undergoing total hip replacement, the preoperative administration of tranexamic acid reduced bleeding by 35%, probably by decreasing induced fibrinolysis. Whether tranexamic acid therapy can replace predonation of autologous blood or intraoperative autotransfusion requires further study.

Aged↗
PubMed2000

Biological significance of reducing glucose degradation products in peritoneal dialysis fluids.

UNLABELLED: Carbohydrates are not stable when exposed to energy; they degrade into new molecules. In peritoneal dialysis (PD) fluids, degradation of glucose occurs during the heat sterilization procedure. The biological consequences of this degradation are side effects such as impaired proliferation and impaired host defense mechanisms, demonstrated in vitro for a great variety of cells. Several highly toxic compounds--such as formaldehyde and 3-deoxyglucosone--have been identified in PD fluids. Carbonyl compounds, apart from being cytotoxic, are also well-known promoters of irreversible advanced glycation end-products (AGEs), which might participate in the long-term remodeling of the peritoneal membrane. Various approaches can be used to reduce the formation of glucose degradation products (GDPs) during heat sterilization. Some examples are shortening the sterilization time, lowering the pH, removing catalyzing substances, and increasing glucose concentration. The latter three factors are employed in the multi-compartment bag with a separate chamber containing pure glucose at high concentration and low pH. Gambrosol trio, a PD fluid produced in this way, shows reduced cytotoxicity, normalized host defense reactions, less AGE formation, and reduced concentrations of formaldehyde and 3-deoxyglucosone. Moreover, in the clinical situation, the fluid turns out to be more biocompatible for the patient, causing less mesothelial cell damage, which in the long term could lead to a more intact peritoneal membrane. CONCLUSION: Glucose degradation products in heat-sterilized fluids for peritoneal dialysis are cytotoxic, promote AGE formation, and cause negative side effects for the patient. Using improved and well-controlled manufacturing processes, it is possible to produce sterile PD fluids with glucose as the osmotic agent but without the negative side effects related to GDPs.

Cells, Cultured↗
PubMed1999

Sonoclot coagulation analysis: a study of test variability.

OBJECTIVE: To test the reproducibility of Sonoclot coagulation analysis (SCA; Sienco Inc, Morrison, CO). The authors wished to determine if the mix/release of the preloaded celite activator in standard Sono-cuvettes could be responsible for the high variation coefficients for SCA parameters with citrated whole blood and if citrated whole blood is optimal for SCA. DESIGN: A prospective trial. SETTING: A large academic teaching medical center. PARTICIPANTS: Eight healthy volunteers. INTERVENTIONS: Repeated blood sampling was performed through indwelling radial artery catheters. Seven different Sonoclot analyzers were used to test seven different types of analysis procedures in the volunteers, involving activators of different types and amounts and in different forms, and the use of citrated or native whole blood. MEASUREMENTS AND MAIN RESULTS: Two-way and one-way ANOVA, variance, variance analysis, and Tukey's test were used to evaluate differences in SCA methods and volunteer influence. A high variance, with SDs up to 200% of the median values of the SCA parameters with recalcified citrated blood and the standard Sono-cuvette, was confirmed. SCA with native blood and/or the use of other types of preloaded activators, ie, kaolin, significantly (p < 0.05) reduced this variance. Repeated SCAs further reduced the variance to 10% to 35% of the variance for a single analysis (standard cuvette and native blood). CONCLUSION: Improvement of the activator in the Sonocuvette, use of native whole blood, and repeated Sonoclot analyses reduced the previously reported high variability of this instrument.

Adult↗
PubMed1999

Peritoneal lymphatic absorption and solute exchange during zymosan-induced peritonitis in the rat.

Lymph flow is elevated in most inflammatory conditions. However, a few previous studies have indicated that peritoneal lymph flow may actually fall during acute peritonitis. This study was performed to explore this issue further and to study the pathophysiology of peritoneal exchange during peritonitis. Therefore, we wanted to assess the total peritoneal clearance (Cl) and the clearance from peritoneum to plasma (Cl --> P) of 125I-labeled albumin (125I-albumin) as well as plasma-to-dialysate clearance (Cl --> D) of Evans blue-labeled albumin together with peritoneal ultrafiltration (UF) profiles and mass transfer area coefficients of 51Cr-EDTA and glucose in rats after acute peritonitis induced by zymosan. Zymosan incubation of the peritoneal cavity (120 mg) for 4 h generally led to a 4- to 10-fold increase in peritoneal fluid white blood cell count, indicating that acute peritonitis had been induced. Then 16 ml of 3.86% Dianeal and 125I-albumin were instilled intraperitoneally, whereas Evans blue-labeled albumin and 51Cr-EDTA were given as infusions intravenously. Compared with control, mass transfer area coefficients for glucose and 51Cr-EDTA increased markedly from 0.43 +/- 0.06 and 0.25 +/- 0.04 to 0.91 +/- 0.06 and 0.59 +/- 0.05 (SE) ml/min, respectively, during peritonitis, whereas Cl and Cl --> D increased from 32.8 +/- 5.6 and 8.6 +/- 1.6 to 74.5 +/- 7.3 and 12.9 +/- 1.0 microl/min, respectively. The UF profile in peritonitis indicated type I loss of UF (resulting from the increases in permeability-surface area product for glucose). However, the Cl --> P declined to 5.9 +/- 1.0 microl/min from 7.9 +/- 0.8 microl/min (P < 0.05) in control. In conclusion, despite marked effects on peritoneal solute transport and on UF, conceivably resulting from vasodilatation and increases in capillary permeability, zymosan-induced peritonitis did not cause any acute increases in direct peritoneal lymphatic absorption.

Animals↗
PubMed1998

Enhanced peritoneal diffusion capacity of 51Cr-EDTA during the initial phase of peritoneal dialysis dwells: role of vasodilatation, dialysate 'stirring', and of interstitial factors.

Mass transfer area coefficients (PS) to small solutes are usually markedly increased during the first 0-15 min of peritoneal dialysis (PD) dwells. This phenomenon may be due to, for example, initial arteriolar vasodilatation and, hence, recruitment of capillary surface area. Other possibilities are an initial discharge (or saturation) of solutes from (in) the interstitium or an increased mixing, i.e., 'macrostirring' caused by the exchange procedure per se. We have investigated these possibilities during acute PD in rats, by assessing PS for 51Cr-EDTA as a function of time [PS(t)]. The discharge effect was studied by saturating the peritoneal interstitium with 51Cr-EDTA by intravenous tracer infusion prior to each dwell and the results compared to those obtained in rats when tracer infusion and dwells were started simultaneously. The potential effect of initial vasodilatation was studied by adding isoproterenol to the dialysis fluid. Finally, the potential influence of an increased interstitial 'microstirring', induced by high glucose concentrations, was investigated by comparison of results for 1.36% Dianeal with those for 3.86% Dianeal. In nonvasodilated rats there was a significant drop in PS(t) between 2.5 and 15 min regardless of whether the rats were preloaded with tracer or not. However, there were no significant changes in PS(t) within the isoproterenol-treated group, indicating that vasodilatation plays a crucial role for the high PS initially. Furthermore, there was no difference in overall PS for 51Cr-EDTA among 1.36 and 3.86% Dianeal dwells. In conclusion, we have found that vasodilatation, but not interstitial discharge (or loading), may explain the inflation of PS occurring during the initial part of PD dwells. In addition, 'macrostirring', induced by the exchange procedure per se, may also be important.

Animals↗
PubMed1996

Liver is not essential for solute transport during peritoneal dialysis.

Based on theoretical calculations on solute exchange capacities of various peritoneal tissues, the liver has been predicted to account for up to 43% of the permeability-surface area product (PS) of the entire peritoneal "membrane" for a small solute (sucrose) during peritoneal dialysis (PD). In these calculations, the abdominal wall and the diaphragm were found to contribute only approximately 10 to 15% of the total PS. However, evisceration has in previous studies been shown to affect the PS characteristics during PD only marginally (10 to 30%). In such evisceration experiments the liver was usually not removed, and therefore it has been suggested that an intact liver might have significantly contributed to the solute exchange under these premises. We assessed the peritoneal PS of 51Cr-EDTA (constantly infused intravenously) and the plasma-to-peritoneal clearance (ClB-->P) of 125I-human serum albumin (RISA) (given as an i.v. bolus) in Wistar rats during acute PD. In one group of rats the liver surface was sealed off using Histoacrylate glue (N = 6) and in another group a 90% hepatectomy was performed, the remaining portion of the liver, usually the right lower lobe, being sealed off by glue (N = 6). A third group was sham operated to serve as control (N = 12). The PS for 51Cr-EDTA was 0.32 +/- 0.03(+/- SE) ml. min-1 (N = 12) during control, 0.32 +/- 0.04 ml.min-1 after "sealing" of the liver surface (N = 6, P > 0.1) and 0.40 +/- 0.03 after hepatectomy (N = 6, P > 0.1), that is, remained unchanged after experimental intervention. The CIB-->P of RISA during control was 5.88 +/- 1.0 microliter.min-1 (N = 10), and was not altered after hepatectomy, 6.17 +/- 0.48 microliters.min-1 (N = 5, P > 0.1), but slightly increased after liver surface sealing (9.69 +/- 1.09 microliters.min-1, N = 5, P < 0.05). In conclusion, the present experiments indicate that the liver does not play an essential role in the overall solute exchange between the plasma and the peritoneal cavity (PC) during PD.

Animals↗
PubMed1996

In vivo inhibition of transcellular water channels (aquaporin-1) during acute peritoneal dialysis in rats.

During peritoneal dialysis (PD), a major portion of the osmotically induced water transport to the peritoneum can be predicted to occur through endothelial water-selective channels. Aquaporin-1 (AQP-1) has recently been recognized as the molecular correlate to such channels. Aquaporins can be inhibited by mercurials. In the present study, HgCl2 was applied locally to the peritoneal cavity in rats after short-term tissue fixation, used to protect the tissues from HgCl2 damage. Dianeal (3.86%) was employed as dialysis fluid, 125I-albumin as an intraperitoneal volume marker, and 51Cr-EDTA (constantly infused intravenously) to assess peritoneal small-solute permeability characteristics. Immunocytochemistry and immunoelectron microscopy revealed abundant AQP-1 labeling in capillary endothelium in peritoneal tissues, representing sites for HgCl2 inhibition of water transport. HgCl2 treatment reduced water flow and inhibited the sieving of Na+ without causing any untoward changes in microvascular permeability, compared with that of fixed control rats, in which the peritoneal cavity was exposed to tissue fixation alone. In fixed control rats, the mean intraperitoneal volume (IPV) increased from 20.5 +/- 0.15 to 25.0 +/- 0.52 ml in 60 min, whereas in the HgCl2-treated rats, the increment was only from 20.7 +/- 0.23 to 23.5 +/- 0.4 ml. In fixed control rats, the dialysate Na+ fell from 135.3 +/- 0.97 to 131.3 +/- 1.72 mM, whereas in the HgCl2-treated rats the dialysate Na+ concentration remained unchanged between 0 and 40 min, further supporting that water channels had been blocked. Computer simulations of peritoneal transport were compatible with a 66% inhibition of water flow through aquaporins. The observed HgCl2 inhibition of transcellular water channels strongly indicates a critical role of aquaporins in PD and provides evidence that water channels are crucial in transendothelial water transport when driven by crystalloid osmosis.

Animals↗
PubMed1996

Theoretical analysis of osmotic agents in peritoneal dialysis. What size is an ideal osmotic agent?

In this article the difference between osmotic fluid flow (ultrafiltration) as driven by osmotic pressure and diffusion through thin leaky membranes is discussed. It is pointed out that water transport induced by osmosis is fundamentally different from the process of water diffusion. Applying modern hydrodynamic pore theory, the molar solute concentration and the solute concentration in grams per 100 mL, exerting the same initial transmembrane osmotic pressure as a 1% glucose solution, was investigated as a function of solute molecular weight (MW). It was then assumed, base on experimental data, that the major pathway responsible for the peritoneal osmotic barrier characteristics is represented by pores of radius approximately 47 A. With increasing solute radius, the osmotic reflection coefficient (sigma) and, hence, the osmotic efficiency per mole of solute will increase. However, simultaneously, the molar concentration per unit solute weight will decrease. The balance point between these two events apparently occurs at a solute MW of approximately 1 kDa. An additional advantage of using solutes of high MW as osmotic agents during peritoneal dialysis (PD), rather than increased osmotic efficiency per se, lies in the fact that large solutes, due to their low peritoneal diffusion capacity, will maintain a sustained rate of ultrafiltration (osmosis) over a prolonged period. To illustrate this, we have performed computer simulations of peritoneal fluid transport according to the three-pore model of peritoneal permselectivity. According to these simulations, 4% of an 800 Da polymer solution (+50 mmol/L above isotonicity) will produce the same cumulative amount of intraperitoneal fluid volume ultrafiltered (UF) during 360-400 minutes as 4% of a 2 kDa polymer solution (+20 mmol/L) or 6.5% of a 10 kDa polymer solution (+6.5 mmol/L) having the same electrolyte concentration as dialysis solutions conventionally used for PD. Similar cumulative UF volumes (during 400 minutes) can be obtained by a 2.5% glycerol (+272 mmol/L) or a 3.2% glucose-containing dialysis solution (+177 mmol/L) with conventional electrolyte composition.

Dialysis Solutions↗
PubMedDate not supplied

Limitation of small-solute exchange across the visceral peritoneum: effects of vibration.

OBJECTIVE: To evaluate the importance of the peritoneal membrane diffusion resistances to small solutes prevailing outside the capillaries in the visceral versus the parietal peritoneum during acute peritoneal dialysis (PD). DESIGN: Experimental study in anesthetized Wistar rats undergoing PD in a single exchange (120 min) using 1.36% Dianeal as dialysis fluid. Vibration, using a standard laboratory shaker at 10 Hz, was used to induce dialysate mixing and reduce the impact of "unstirred layers" in intact and eviscerated rats. Nonvibrated rats served as controls. MEASUREMENTS: The mass transfer area coefficient (PS) for chromium 51-ethylenediamine tetraacetic acid (51 Cr-EDTA), continuously infused intravenously, the plasma-to-peritoneal clearance (Cl-->D) of radioiodinated (125I) serum albumin (human)(RISA), as well as the total clearance out of the peritoneal cavity (Cl) of Evans blue labeled albumin, given as an intraperitoneal volume marker, and the portion of this Cl reaching the plasma per unit time (Cl-->P) were assessed. RESULTS: In intact rats there was a marked increase in PS for 51 Cr-EDTA, from 0.297 +/- 0.036 mL/min to 0.642 +/- 0.122 mL/min (n = 7, p < 0.01), and a moderate increase in Cl and Cl-->D, from 37.6 +/- 1.3 microL/min to 63.3 +/- 9.0 microL/min and from 6.04 +/- 0.51 microL/min to 9.54 +/- 0.93 microL/min (n = 7, p < 0.05), respectively, upon vibration. However, the plasma absorption clearance of albumin (Cl-->P) was unchanged after vibration. Furthermore, in eviscerated rats, vibration caused no significant changes in either of the exchange parameters measured. CONCLUSION: In conclusion, the visceral peritoneal transport of small solutes is normally limited by the presence of diffusion resistance outside the capillaries, which may be markedly reduced by "stirring" of the dialysate by vibration. Normally, the parietal, rather than the visceral, peritoneum is the major site for small-solute mass transfer in stationary animals. However, the visceral peritoneum apparently becomes increasingly important after stirring. The moderate increases in transperitoneal clearances of macromolecules occurring upon vibration, which were quite unexpected, indicate that vibration may also increase the dialysate/peritoneal membrane contact and/or cause some recruitment of capillaries.

Animals↗
PubMedDate not supplied

Effects of acidity, glucose degradation products, and dialysis fluid buffer choice on peritoneal solute and fluid transport in rats.

OBJECTIVE: To evaluate the effects of acidity, glucose degradation products (GDP), and different solution buffer systems on solute and fluid transport during acute peritoneal dialysis (PD) in rats. DESIGN: Dialysis fluid (16 mL) containing 2.5% glucose as the osmotic agent was instilled intraperitoneally in Wistar rats (280 g) via a thin catheter in dwells lasting 4 hours. Blood and dialysis fluid samples (25 microL) were taken for measurement of glucose, sodium, and radioactive markers. The mass transfer area coefficient (MTAC or PS) for glucose and for 51Cr-EDTA (given as an intravenous infusion) and the peritoneal clearance (Cl) of 125I albumin (RISA), as well as the clearance of RISA to plasma (Cl --> P) were assessed for a commercial, heat-sterilized, acidic PD solution (2.5% glucose, pH 5.5; Gambrosol, Gambro, Lund, Sweden), containing GDP, and for four filter-sterilized solutions containing either lactate (40 mmol/L, pH 5.5 or 7.2), bicarbonate (38 mmol/L, pH 7.2), or pyruvate (40 mmol/L, pH 7.2) as buffers and being devoid of GDP. RESULTS: The initial pH of the acidic solutions increased rapidly, and attained physiological levels within 40 minutes. The initial drop of sodium, which is expected during the first part of the dwell, was significantly more pronounced with neutral than with acidic lactate. The PS for glucose and 51Cr-EDTA were slightly, but significantly, higher with the acidic and heat-sterilized solution (Gambrosol) than with the neutral, sterile-filtered lactate-buffered solution (p < 0.01), especially early during the dwell. Such an increase may be due to initial vasodilatation, and hence, recruitment of capillaries by the combination of acidity and GDP. However, there were no significant differences with respect to small solute PS values among sterile-filtered solutions, regardless of the presence of acidity or of buffer choice. CONCLUSION: There were no major differences in fluid and solute transport among sterile-filtered PD solutions having differing buffer systems and pH. Neither were there any effects of GDP alone. However, the combination of a low pH and the presence of GDP in the PD solutions seemed to cause significant increases in peritoneal small solute transport.

Animals↗