Ringer's Lactate Group Research Articles

Half-molar sodium-lactate solution has a beneficial effect in patients after coronary artery bypass grafting

To compare two solutions for fluid resuscitation in post-coronary artery bypass grafting (CABG) surgery patients: Ringer's lactate (RL) versus a new solution containing half-molar sodium-lactate (HL). Prospective randomized open label study. The first 12 h post-CABG surgery in an intensive care unit (ICU). There were 230 patients enrolled in the study: 208 were analyzed, with 109 from the HL group and 99 from the RL group. Patients received over the first 12 h post-CABG 10 ml kg BW(-1) HL solution in the HL group versus 30 ml kg BW(-1) of RL solution in the RL group. Hemodynamic status, body fluid balance and inotrope utilization were compared in the two groups. Post-operative cardiac index increase was significantly higher in HL than in RL (P = 0.02), while mean arterial pressure and other hemodynamic parameters were comparable together with urinary output, indicating similar tissue perfusion in both the groups despite a much lower fluid infusion in the HL group. Therefore, a significant negative fluid balance was achieved in the HL but not in the RL group (-790 +/- 71 vs. +43 +/- 115 mL 12 h(-1), P < 0.0001 for HL and RL, respectively). None of the enrolled patients exhibited side effects related to the treatment. Half-molar lactate solution is effective for fluid resuscitation in post-CABG patients. Compared to Ringer's Lactate, its use results in a significantly higher cardiac index with less volume being infused, resulting in a very negative post-operative body fluid balance.

Effects of colloid and crystalloid solutions on endogenous activation of fibrinolysis and resistance of polymerized fibrin to recombinant tissue plasminogen activator added ex vivo

The study was conducted to explore the effects of colloid and crystalloid solutions on activation of fibrinolysis during orthopaedic surgery and to determine whether fluids facilitate clot dissolution at a particular fibrinolytic activity. Tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) were measured in plasma samples of 66 orthopaedic patients randomly receiving gelatin solution, hydroxyethyl starch (HES) (130/0.4), or exclusively Ringer's lactate solution. Plasma obtained before induction of anaesthesia (undiluted) and at the end of surgery (diluted) was exposed to recombinant tissue plasminogen activator (r-tPA) in vitro and analysed by modified thrombelastography (ROTEM). There were similar changes in t-PA and PAI-1 concentrations in the gelatin, HES, and Ringer's lactate groups. When compared with the effect of r-tPA on undiluted plasma samples, the presence of colloids prompted faster clot dissolution than did Ringer's lactate solution. Lysis index at 30 min decreased significantly [median (min/max); P vs Ringer's lactate solution] to 43 (1/82)% (P=0.007), 14 (3/70)% (P<0.001), and 91 (34/97)%, lysis onset time decreased to 1269 (1054/1743) s (P=0.007), 972 (490/1565) s (P<0.001), and 1970 (1260/2165) s, and lysis time to 2469 (1586/3303) s (P=0.019), 2002 (1569/3600) s (P=0.006), and 3012 (2017/3600) s in the gelatin, HES, and Ringer's lactate groups, respectively. The type of i.v. fluid used does not influence endogenously occurring fibrinolytic activity in patients undergoing major orthopaedic surgery. However, during hyperfibrinolysis, the presence of HES or gelatin solution facilitates clot disintegration to a greater extent than Ringer's lactate solution, because the weaker clots formed with colloids dissolve faster.

Effects of Normal Saline vs. Lactated Ringer's during Renal Transplantation

Aim. We hypothesized that normal saline (NS) may have more deleterious effects compared with lactated ringer (LR) in kidney transplant recipients because of the higher risk of acidosis and higher levels of serum potassium. Thus, the aim of this study was to determine the safety of LR if used during a renal transplant. Methods. Adults undergoing kidney transplantations were enrolled in a double-blinded randomized prospective clinical trial. They were divided into two groups in order to receive NS and LR infusion as intraoperative IV fluid replacement therapy. Results. There was a significant difference in the serum potassium level (p = .000) and the PH (p = .007) between the two groups at the end of transplantations. Two patients in the LR group lost their kidneys due to vascular graft thrombosis. In other words, hyperkalemia and acidosis occurred more frequently in the NS group while thrombotic events may be of concern in the LR group. Conclusion. Compared with NS, LR infusion may lead to a lower serum potassium level and a lower risk of acidosis, while there is major concern of the hypercoagulable state in these patients.

Efeitos neuroprotetores do diltiazem em coelhos com oclusão da aorta

In the present study, we aimed to determine the protective effect of the perfusion of the distal aorta with diltiazem and ringer lactate solution on the spinal cord. Twenty-seven New Zealand rabbits were used in which spinal cord ischemia was provided by occlusion of the aorta for thirty minutes. Experimental animals were divided into four groups: group A (n=4), the sham operation group; group B (n=8) in which intraaortic balloon occlusion alone was applied; group C (n=7), ringer lactate group in which ringer lactate was perfused into distal aorta at a rate of 40 ml/kg, hr, following intraaortic balloon occlusion; group D (n=8) diltiazem group in which diltiazem 40 mg/kg, hr, in Ringer lactate was perfused into distal aorta following intraaortic balloon occlusion. Motor function of hind limbs was evaluated by Tarlov's scoring system. After observation, spinal cords were removed for histopathological evaluation. The degree of histopathological injury was well correlated with neurological function. The most severe histopathological injury and neurological dysfunction occurred in group B, followed by group C, D and A respectively. No injury or neurological dysfunction occurred in the sham group. The protective effect of diltiazem on both histopathological injury and neurological function was significant in comparison with control groups.

Hemostatic Changes After Crystalloid or Colloid Fluid Administration During Major Orthopedic Surgery: The Role of Fibrinogen Administration

To explore whether disturbed fibrin polymerization is the main problem underlying dilutional coagulopathy and can be reversed by fibrinogen administration, we conducted a prospective study using modified thrombelastography (ROTEM). Sixty-six orthopedic patients randomly received modified gelatin solution, hydroxyethyl starch 130/0.4, or exclusively Ringer lactate solution. ROTEM analysis was performed, concentrations of coagulation factors and markers of thrombin generation were measured. Fibrinogen concentrate (Hemocomplettan) was administered (30 mg/kg) when thrombelastographically measured fibrinogen polymerization was critically decreased. The alpha angle, clot firmness, and fibrinogen polymerization (median [min to max]) significantly decreased in the patients receiving hydroxyethyl starch (area under the curve minus baseline (-5 [-9 to -2]), followed by gelatin solution (-3 [-8 to 0]), with the least reductions seen for Ringer lactate solution (-2 [- 4 to 1]) (colloids versus Ringer lactate P < 0.0001). Thirteen patients in the colloid groups but none in the Ringer lactate group needed fibrinogen concentrate to maintain borderline clot firmness. Activity of FVII, FVIII, FIX, and von Willebrand ristocetin activity decreased significantly with colloids. Thrombelastographically measured coagulation time, molecular markers of thrombin generation, and activity of all other coagulation factors were comparable in all groups. Disturbance of fibrinogen/fibrin polymerization is the primary problem triggering dilutional coagulopathy during major orthopedic surgery. The magnitude of clot firmness reduction is determined by the type of fluid used, with hydroxyethyl starch showing the most pronounced effects. These undesirable effects of intravascular volume therapy can be reversed by increasing fibrinogen concentration by administering fibrinogen concentrate, even during continuing blood loss and intravascular volume replacement.

PULMONARY FUNCTION IS BETTER PRESERVED IN PIGS WHEN ACUTE NORMOVOLEMIC HEMODILUTION IS ACHIEVED WITH HYDROXYETHYL STARCH VERSUS LACTATED RINGER'S SOLUTION

Acute normovolemic hemodilution (ANH) has been proposed to decrease the need for allogenic blood transfusion. Consequently, great amounts of fluids are necessary to maintain hemodynamics during and after blood removal. The aim of this experiment was to evaluate the oxygenation, respiratory compliance, and lung structure during ANH performed with lactated Ringer's solution and hydroxyethyl starch (HES). Gas exchange, extravascular lung water, intrathoracic blood volume, serum osmolality, respiratory mechanics, and optical and electronic microscopy of lung biopsies were evaluated. Animals were randomized into three groups: CTL (control, n = 9), HES (HES 6% 200/0.5, n = 9), and LR (lactated Ringer's solution, n = 9). Animals in groups HES and LR underwent ANH to reach a preestablished hematocrit of around 15%. The removed blood was replaced with HES in a proportion of 1:1 and with lactated Ringer's solution 3:1. The LR group demonstrated a tendency for a marked time-dependence decrease in compliance (P = 0.013 in T2; P = 0.008 in T3) and in Pao2/fraction of inspired oxygen (Fio2) ratio (P = 0.033 in T2) as well as an increase in (A-a) Grad O2 (P = 0.037 in T2). Extravascular lung water and intrathoracic blood volume did not present any significant variation among the groups. In contrast, serum osmolality presented a significant decline in animals hemodiluted with lactated Ringer's solution. Optical and electronic microscopy of lungs biopsies revealed moderate to serious collapses and basement membrane enlargement in LR group. In this kind of experimental model, ANH with 6% HES (200/0.5) seems to preserve lung structure better as evidenced by maintenance of oxygenation indexes and respiratory compliance when compared with that in the Ringer's solution hemodiluted group.

Intrapartum maternal glucose infusion and fetal acid–base status

Objective To compare the effects of an intrapartum infusion of a lactated Ringer solution or a glucose-boosted saline solution on the acid–base status of umbilical arterial blood. Method In a prospective clinical trial 178 women in labor were randomized to receive intravenously either a lactated Ringer solution or a saline solution boosted with 5% glucose. Umbilical arterial blood was then assessed for acid–base status. Results There were significant differences between the lactated Ringer group and the glucose group in umbilical artery pH values (7.25 ± 0.07 vs. 7.28 ±0.06; P = 0.008), pCO 2 values (44.8 ± 5.6 mm Hg vs. 41.6 ± 4.1 mm Hg; P = 0.001), and base excess (− 7.3 ± 2.1 mEq/L vs. − 6.6 ± 1.8 mEq/L; P = 0.02). Conclusion Intrapartum intravenous fluid containing a 5% glucose solution reduces umbilical cord acidemia and hypercarbia.

Is Euro-Collins better than ringer lactate in live related donor renal transplantation?

Objectives:Euro-Collins and University of Wisconsin are preferred solutions in cadaveric renal transplantation. There are no guidelines regarding the perfusion fluids in live donor renal transplantation. We studied whether Euro-Collins was better than Ringer lactate in terms of protecting allograft function.Materials and Methods:A double-blind permuted randomized trial comparing Euro-Collins and Ringer lactate was performed on 100 patients undergoing live related donor renal transplantation. Outcome variable was serum creatinine.Results:Age, sex, donor nephrectomy and ischemia times, kidney temperature, time of first appearance of urine was not significantly different in both the groups. Fall in serum creatinine was significantly more in Euro-Collins than Ringer lactate in the first postoperative week (P-<0.05). The time to reach nadir creatinine was 4.97 days in Euro-Collins and 7.75 days in the Ringer lactate group (P-0.088). Serum creatinine was significantly lower in the Euro-Collins group till six months, thereafter it equalized with Ringer lactate. When individual parameters were analyzed for time to nadir creatinine, only the cold ischemia time of > 80 min was found to be significant (P-0.024). Twelve kidneys in Euro-Collins and 17 in the Ringer lactate group had cold ischemia times of ≥80 min and time to nadir creatinine was 4.33 ±3.74 and 12.76± 12.68 days (P-0.035).Conclusions:Renal function normalized rapidly when Euro-Collins was used. Cold ischemia time of ≥ 80 min was the most important factor affecting the graft function and perfusing with Euro-Collins could protect the allograft.

Fluid preload before spinal anaesthesia in Caesarean section

We evaluated the effect of two different preload solutions: (i) Ringer's lactate (compound sodium lactate intravenous infusion BP) and (ii) 0.9% sodium chloride solution on the neonatal acid-base status of the newborn infants. The two standard regimens were compared to detect a possible difference. A 2 L crystalloid fluid bolus was administered immediately before spinal anaesthesia for elective Caesarean section in two groups of 20 healthy parturients, while rigorously maintaining maternal normotension. No significant differences in the Apgar scores at 1 and 5 min, or infant well-being were demonstrated in either of the two groups. The data show that umbilical artery PCO2 is lower in the Ringer's lactate group and that pH is insignificantly higher by 0.03. The choice of Ringer's lactate or saline for fluid preload does not have any effect on neonatal well-being.

Can albumin administration relieve lung injury in trauma/hemorrhagic shock?

To study the effect of albumin administration on lung injury in trauma/hemorrhagic shock (T/HS). Sixty experimental animals were randomly divided into three groups: rats undergoing laparotomy without shock (T/SS); rats with T/HS and resuscitation with blood plus twice the volume of shed blood as Ringer's lactate (RL), and rats with T/HS and resuscitation with blood plus additional 3 mL of 50 g/L human albumin. Expression of polymorphonuclear neutrophil (PMN) CD11b/CD18, intercellular adhesion molecule-1 (ICAM-1) of jugular vein blood and the severity of lung injuries [determined mainly by measuring activity of lung tissue myeloperoxidase (MPO) and lung injury score (LIS)] were measured after a 3-h recovery period. All three groups showed a significant difference in the expressions of CD11b/CD18, ICAM-1, and severity of lung injury. The expressions of CD11b/CD18 in T/SS group, T/HS + RL group, T/HS + albumin group were 17.76% +/- 2.11%, 31.25% +/- 3.48%, 20.36% +/- 3.21%, respectively (F = 6.25, P < 0.05). The expressions of ICAM-1 (U/mL) in T/SS group, T/HS + RL group, T/HS + albumin group were 258.76 +/- 98.23, 356.23 +/- 65.6, 301.01 +/- 63.21, respectively (F = 5.86, P < 0.05). The expressions of MPO (U/g) in T/SS group, T/HS + RL group, T/HS + albumin group were 2.53 +/- 0.11, 4.63 +/- 1.31, 4.26 +/- 1.12, respectively (F = 6.26, P < 0.05). Moreover, LIS in T/HS + RL group, T/HS + albumin group was 2.62 +/- 0.23, 1.25 +/- 0.24, respectively. The expressions of CD11b/CD18, ICAM-1 and MPO in T/HS + RL group were significantly increased compared to T/SS group (P = 0.025, P = 0.036, P = 0.028, respectively). However, administration of 3 mL of 50 g/L albumin significantly down-regulated the expressions of CD11b/CD18, ICAM-1 and lung injury index (MPO and LIS) when compared with the T/HS + RL rats (P = 0.035, P = 0.046, P = 0.038, P = 0.012, respectively). The infusion of albumin during resuscitation period can protect lung from injury and decrease the expressions of CD11b/CD18, ICAM-1 in T/HS rats.

Ringer’s lactate solution remains in the peritoneal cavity after laparoscopy longer than expected

To evaluate by serial ultrasound scans how long a Ringer's lactate instillation remains in the peritoneal cavity after laparoscopy. Prospective, randomized, double blind, clinical trial. Tertiary care, university hospital. Thirty-six patients undergoing diagnostic or minor operative laparoscopy. At the end of laparoscopy, the patients were tilted to an anti-Trendelenburg position and all fluid was aspirated. The patients were then randomized to receive an instillation of 300 mL of Ringer's lactate or no fluid instillation. Serial transvaginal ultrasound scans were performed at the end of surgery and at 24, 48, and 96 hours after the surgery. Through direct measurements of scalar fluid volumes instilled in the operating room and real-time ultrasound comparisons, an empiric formula was calculated to correlate actual intraperitoneal volumes to ultrasonically derived measurements of fluid pockets. With this formula, the volume of intraperitoneal fluid at 24, 48, and 96 hours after surgery was calculated. Twenty-four hours after surgery, a mean volume of 184 mL was present in the Ringer's lactate group versus 46 mL in the control group. At 48 hours after surgery, the mean volumes were 78 mL versus 30 mL, respectively. No statistically significant differences were found after 96 hours. Peritoneal absorption of instilled crystalloids is traditionally reported to be 30 to 60 mL/hour. We report detecting statistically significant amounts of fluid at 24 and 48 hours after surgery, after infusion of 300 mL of Ringer's lactate. This suggests that fluid remains in the peritoneal cavity longer than traditionally believed.

Wash-out of the non–heart-beating donor liver: A comparison between ringer lactate, HTK, and polysol

The solution of choice for wash-out of non–heart-beating donor (NHBD) livers ishistidine tryptophan ketoglutarate (HTK). This solution has a lower viscosity, due to absenceof a colloid, and is less expensive as compared to the University of Wisconsin (UW) solution.A new preservation solution for machine perfusion was developed, named Polysol. In orderto apply Polysol clinically in NHBD organ retrieval, the efficacy as a wash-out solution wasinvestigated. Methods After a warm ischemic time of 30 minutes, the rat liver was washed out via theportal vein with 50 mL of either ringer lactate (RL), HTK or Polysol. After wash-out andharvesting, the liver was reperfused with Krebs-Henseleit buffer. Samples were taken toassess hepatocellular injury and liver function. Results Liver damage parameters were elevated in the RL group as compared to the HTKand Polysol groups. Liver/rat weight ratios were significantly lower after wash-out withPolysol. Overall, no differences were seen in ammonia clearance and bile production. Inconclusion, wash-out of the NHBD liver with Polysol results in equal to improvedreperfusion results as compared to HTK. Polysol is feasible as a wash-out solution incombination with machine perfusion using Polysol.

Red blood cell aggregation during cardiopulmonary bypass: a pathogenic cofactor in endothelial cell activation?

The bio-incompatibility of the cardiopulmonary bypass (CPB) circuit and the use of artificial colloids trigger massive defense reaction that involves endothelial cells and several blood cells: platelets, neutrophils, monocytes, red blood cells (RBC) and lymphocytes. Investigating the effects on RBC aggregation and endothelial cells activation, the present study addresses two different prime solutions commonly used in the clinical practice. RBC aggregation was measured by means of Laser-assisted Optical Rotation Cell Analyzer, in an in vitro study designed to mimic the human blood-material interactions during extracorporeal circulation. A clinical study investigating endothelial activation was conducted in 20 patients undergoing elective coronary bypass surgery, randomly assigned for CPB using two different priming solutions: HAES-steril 6% (HES 200/0.5) and Voluven 6% (HES 130/0.4). Circulation trough a Chandler loop of HES-blood mixes altered significantly RBC aggregability. The use of HES 130/0.4 resulted in marked decrease in RBC aggregation (aggregation index (AI) before and after circulation was 23.5+/-3.8 and 18+/-2.9, respectively), no significant differences being found when compared with Ringer's lactate group. The use of HES 200/0.5 resulted in better maintained RBC aggregation (AI 39.7+/-5.9 and 29.7+/-4.7 before and after circulation, respectively). The AI measured for the whole blood (control) sample was 61.9+/-4.9 before circulation, and 58.1+/-4 after. Markers of endothelial activation (von Willebrand factor (vWF), thrombomodulin (TM), tissue plasminogen activator (tPA) and E-selectin) significantly increased during CPB. Differences between HES treatment groups were evident post-bypass. While the markers of endothelial activation returned to baseline in HES 200/0.5 group, HES 130/0.4 was associated on the first post-operative day with further increase of vWF and tPA. RBC aggregation significantly drooped as consequence of blood dilution and blood-material interaction. We reason that low RBC aggregation added to plasma viscosity reduction and non-physiologic flow conditions during extracorporeal circulation are important factors contributing to loss of shear stress at the venous endothelial wall. The loss of shear stress triggers complex signaling leading to endothelial activation. Additional fundamental research is needed in order to verify the hypothesis introduced by the present study. Characterizing the impact of rheologic parameters on endothelial function could prove to be valuable in patients undergoing CPB.

Genetic modification of cold-preserved renal grafts using HSP70 or bcl-2 HVJ-liposome method

Background: We tested the hypothesis that the best time for genetic modification is while the cell viability of the graft is reduced for long-term preservation. The hemagglutinating virus of Japan (HVJ)-liposome method, a nonviral gene transfer technique, was used with a luciferase gene to test the efficacy of protein induction under the critical preservation time. Furthermore, we tested this genetic modification with heat shock protein (HSP) 70 or bcl-2 genes to prevent primary nonfunction (PNF) after long-term preservation. Methods: Orthotopic rat renal transplantation (RT) was performed using the cuff technique in the syngeneic combination of Lew (major histocompatible complex, haplotype: RT1 l). Rat kidney grafts were preserved for 24 or 48 h in University of Wisconsin (UW) or Ringer's lactate solution using HVJ method with the luciferase gene. Rats with gene-transfected kidneys were re-laparotomized 48 h after transplantation to estimate the lack of arterial flow in the graft and killed for histological evaluation of the degree of PNF luciferase intensity assay. Then, two functional genes (HSP70 or bcl-2) were tested for the occurrence of PNF and histological and immunohistochemical analysis of the grafted kidneys preserved for 48 h in the UW solution. Results: In the kidneys preserved for 24 h, 50% of the Ringer's lactate group had PNF; but all of the UW group had sufficient blood flow. The graft viability was well corrected by the degree of luciferase intensity. The PNF rate was significantly suppressed in the bcl-2 gene-transfer group, and tended to be reduced in the HSP70 group. Conclusions: The HVJ-liposome method effectively induced the foreign gene for kidney grafts even in the cold-preservation solution. Induction of bcl-2 or the HSP70 gene reduced the occurrence of PNF in the rat renal graft. The results suggest that gene transfer not only maintains graft viability, but also graft activation.

Influence of Early Drainage of Intraperitoneal Phospholipids on Efficacy of Adhesion Prevention

Postoperative peritoneal adhesions impose a long-term risk of morbidity and mortality. Adjunctive means are needed to prevent these complications. In previous studies we could demonstrate the efficacy and safety of intraperitoneally applied phospholipids with regard to adhesion prevention and wound healing, respectively. The assumption is that phospholipids rapidly adhere to the peritoneal surface and to the mesothelial lesions. This study was designed to evaluate the influence of early drainage of the administered fluid volume on the control of adhesion formation. Forty chinchilla rabbits underwent median laparotomy and standardized abrasion of circumscript areas of the ventral abdominal wall, the cecum, and the ileum. The animals randomly received either 75 mg/kg body weight of phospholipids in a volume of 5.0 mL/kg body weight ( n = 20) or the same volume of Ringer's lactate solution ( n = 20) prior to closing the laparotomy wounds. In 50% of the rabbits with either medication, 80% of the volume was recovered after 30 min before final closure of the abdominal wall ("drainage"). In the remaining animals the intraabdominal fluid load was not evacuated ("no drainage"). At day 10 after surgery all rabbits were sacrificed for evaluation of adhesion areas by computer-aided planimetry and histopathologic examination. The mean areas of adhesion in both Ringer's lactate groups were significantly larger than in the comparable phospholipid groups ( p < .05). In the Ringer's lactate groups, adhesions averaged 341.7 (318.6) mm 2 without and 263.3 (275.5) mm 2 with drainage. In the phospholipid groups the respective mean areas reached only 24.6 (36.7) mm 2 without drainage and 27.0 (49.7) mm 2 following evacuation of the fluid 30 min after administration (median, mean in parentheses). These results prove the efficacy of phospholipids after a limited contact period of 30 min. The frequent use of drains in abdominal surgery will not impair the beneficial effect of phospholipids on prevention of adhesions.

Hemorrhagic Shock Resuscitation with a Low Molecular Weight Starch Reduces Neutrophil-Endothelial Interactions and Vessel Leakage in vivo

The polymorphonuclear neutrophil (PMN) has been implicated in the pathogenesis of endothelial cell (EC) damage and organ injury following hemorrhagic shock. Pentastarch (PTS), a low substituted medium molecular weight (MW) colloid, improves hemodynamics in hypovolemic shock and cardiac surgery. No data exist comparing the immunomodulation of PTS and Ringer's lactate (RL) on the activation of PMN in hemorrhagic shock in vivo. Using an in vivo murine hemorrhagic shock model (blood withdrawal to maintain 50 mmHg x 45 min), circulating PMN were observed every 15 minutes using intravital microscopy on cremaster muscle. EC-PMN interactions (videorecorded and subsequently analyzed blindly), vessel leakage (live epifluorescence after injection of 50 mg/kg fluorescent albumin) and PMN expression of L-selectin (immunofluorescent monoclonal antibodies and flow cytometry) were evaluated in three resuscitation groups: PTS (7.14 mL/kg 10% pentastarch/0.9% NaCl + shed blood, n = 13), RL (RL [2 x shed blood volume] + shed blood, n = 13) and SHAM (0 hemorrhage, 0 resuscitation, n = 9). Significance was evaluated by ANOVA with Bonferroni correction. PMN rolling was significantly diminished in PTS and SHAM as compared to RL animals at all time points. Similar differences were found in PMN adherence to EC at most time points onwards from 15 minutes following resuscitation. In vivo vessel permeability was lowest in SHAM and PTS animals (mean 0.274 +/- 0.07 and 0.356 +/- 0.15, respectively, p > 0.05) and highest in RL animals (0.667 +/- 0.09, p < 0.001 vs PTS or SHAM). PMN L-selectin expression tended to be higher in the RL group than either SHAM and PTS groups. There were no flow-mechanics differences between groups (vessel diameter, mean red cell velocity, shear stress, shear rate). 10% pentastarch reduces RL-associated EC-PMN interactions and vessel leakage following hemorrhagic shock. These results support the use of low MW starches to resuscitate hemorrhagic shock, potentially reducing PMN-mediated tissue injury.

Prevention of postoperative adhesion formation in rat uterine horn model by nimesulide: a selective COX-2 inhibitor.

Pelvic surgery is one of the main causes of intraperitoneal (i.p.) adhesions that create various medical problems including pelvic pain, bowel obstructions and female infertility. A rat model was used to investigate the efficacy of nimesulide, a selective cyclooxygenase-2 inhibitor, in the prevention of adhesion formation. Fifty Wistar-Albino rats underwent bilateral uterine horn injury with a unipolar cautery. Study groups were as follows: (i) control group, no adjuvant therapy; (ii) i.p. Ringer's lactate group, 2 ml Ringer's lactate solution was instilled i.p.; (iii) i.p. Ringer's lactate plus nimesulide group, 1 ml Ringer's lactate plus 1 ml nimesulide (0.5 mg/ml) were given i.p.; (iv) intramuscular (i.m.) nimesulide group, 1 ml i.m. nimesulide (0.5 mg/ml) was given preoperatively for 5 days; and (v) i.p. nimesulide group, 1 ml nimesulide (0.5 mg/ml) was instilled i.p. At the end of the study all animals were killed, and a standard adhesion scoring system was applied by a blinded examiner. The mean adhesion extent in study groups was as follows: 1.33 +/- 0.76 in control group, 1.40 +/- 0.90 in i.p. Ringer's lactate group, 0.75 +/- 0.70 in i.p. Ringer's lactate plus nimesulide group, 0.25 +/- 0.44 in i.m. nimesulide group and 0.31 +/- 0.70 in i.p. nimesulide group. The mean +/- SD adhesion severities of control, i.p. Ringer's lactate, i.p. Ringer's lactate plus nimesulide, i.m. nimesulide, and i.p. nimesulide groups were 0.58 +/- 0.35, 0.30 +/- 0.41, 0.27 +/- 0.3, 0.12 +/- 0.28 and 0.15 +/- 0.35 respectively. The lowest adhesions were found in the groups treated with nimesulide i.m. and nimesulide i.p. ( P < 0.05). This study showed that preoperative i.m. or postoperative i.p. administration of nimesulide to the site of injury reduced the formation of postoperative adhesions in a rat uterine horn model.

Ultrastructure of basement membranes of peritoneal capillaries in a chronic peritoneal infusion model in the rat

Long-term peritoneal dialysis with glucose- based dialysis solutions has been associated with diabetiform alterations of peritoneal tissue. A peritoneal infusion model in the rat was developed to study the effect of chronic infusion of a glucose-based dialysis solution and an isotonic non-glucose solution on the ultrastructure of the basement membranes of peritoneal capillaries. The effect of ageing was also studied in an untreated control group. A vascular access port (Rat-o-Port) with attached peritoneal catheter was implanted subcutaneously in the neck of nine male Wistar rats. The rats were divided randomly into three groups: the glucose group (n = 3) was infused daily for 20 weeks with 60 ml/kg body weight 3.86% glucose solution. A control group (n = 2) was infused daily for 20 weeks with 60 ml/kg body weight Ringer's lactate. The untreated control group (n = 4) was studied at the onset of the experiment and after 20 weeks. Omental tissue was obtained from each rat at the end of the experimental period for ultrastructural examination. Extensive lamination of basement membranes of omental capillaries was found in the glucose group. This was in contrast to the untreated control group where clear, single basement membranes were seen at the onset of the experiment and after 20 weeks. These latter findings were similar to those in the Ringer's lactate group. The chronic infusion model in the rat is suitable for the investigation of the effects on the ultrastructure of peritoneal capillaries of chronic exposure to dialysis fluids. The duplications of basement membranes of omental capillaries found in the glucose group show a striking resemblance to those found in long-term peritoneal dialysis patients. This suggests a role for glucose in the development of peritoneal ultrastructural alterations found in long-term peritoneal dialysis.

Decrease in the Total Amount of Extracellular Bicarbonate Is Not Dilution

Decrease in the Total Amount of Extracellular Bicarbonate Is Not Dilution

Cardiopulmonary bypass alters vasomotor regulation of the skeletal muscle microcirculation

Cardiopulmonary bypass (CPB) is associated with alterations in the regulation of organ perfusion and vascular permeability. The purpose of this study was to examine the effects of hypothermic CPB on the regulation of the skeletal muscle microcirculation and the modulating influence of the priming solution. Sheep were placed on hypothermic CPB with a prime of either Pentastarch hydroxylethyl starch (HS) solution (n = 7), a solution in which HS is conjugated with deferoxamine (n = 7), or Ringer's lactate solution (n = 7). Sheep were placed on hypothermic CPB (27 degrees C) for 90 minutes while the heart was protected with cold blood cardioplegia. Sheep were then separated from CPB and perfused for an additional 3 hours off CPB. Hemodynamics and total water content were measured. In vitro relaxation responses of gracilis muscle arterioles (70 to 180 microns) to the endothelium-dependent agent acetylcholine, the endothelium-independent cyclic GMP-mediated vasodilator sodium nitroprusside, the beta-adrenergic agonist isoproterenol, and the adenylate cyclase activator forskolin were studied. No statistically significant hemodynamic differences were observed between groups. However, weight gain was significantly less when the priming solution was HS or HS-deferoxamine compared to when Ringer's lactate was used. Skeletal muscle arteriolar relaxations to the endothelium-dependent vasodilator acetylcholine and the beta-adrenergic agonist isoproterenol were impaired after CPB in the HS and Ringer's lactate groups. Acetylcholine response was preserved in the HS-deferoxamine group, whereas the response to isoproterenol remained impaired. The responses to sodium nitroprusside and forskolin were similar in all groups. Skeletal muscle microvascular endothelium-dependent relaxation and beta-adrenergic relaxation are reduced after CPB using either a crystalloid or HS prime. Skeletal muscle microvascular endothelial dysfunction may be attributable to oxygen-derived free radical-mediated injury, whereas altered beta-adrenergic regulation is attributable to mechanisms other than the generation of oxygen-derived free radicals during CPB.