犬内毒素性休克时琥珀明胶和乳酸钠林格氏液的容量动力学

目的比较犬内毒素性休克时琥珀明胶和乳酸钠林格氏液的容量动力学。方法健康杂种犬20只,雌雄不拘,随机分为4组（n=10）,乳酸钠林格氏液组（CL组）经30min静脉输注乳酸钠林格氏液30ml/kg;琥珀明胶组（CG组）经30min静脉输注琥珀明胶10ml/kg;内毒素＋乳酸钠林格氏液组（LL组）静脉注射内毒素250μg/kg,再经30min静脉输注乳酸钠林格氏液30ml/kg;内毒素＋琥珀明胶组（LG组）静脉注射内毒素250μg/kg,再经30min静脉输注琥珀明胶10ml/kg。补液期间每隔5分钟测定血红蛋白浓度和红细胞压积;记录血液动力学指标和总尿量。应用物质守恒定律和容量动力学理论,计算血浆容量增加、外周容量增加、容量扩张效率、目标容积（V）和清除率（Kr）。结果与CL组比较,CG组V和Kr降低,LL组V升高（P〈0.05）;与CG组比较,LG组V和Kr升高（P〈0.05）;与LL组比较,LG组V和K降低（P〈0.05）。与CG组和LG组比较,CL组和LL组血浆容量增加和容量扩张效率降低,外周容量增加升高（P〈0.05）;与CL组和CG组比较,LL组和LG组血浆容量增加和容量扩张效率降低,外周容量增加升高（P〈0.05）。结论犬内毒素性休克时,乳酸钠林格氏液的扩容效率较琥珀明胶降低更为明显。     

Coagulation effects of in vitro serial haemodilution with a balanced electrolyte hetastarch solution compared with a saline-based hetastarch solution and lactated Ringer's solution

The hydroxyethyl starches are a group of compounds that has been associated with impairment of coagulation when large volumes are administered. The thrombelastograph is commonly used to assess point-of-care whole blood coagulation. Little is known about the dose-response relationships of haemodilution, and it is reasonable to assume that a linear association exists. This may not be the case with altered electrolyte compositions of the fluids used for haemodilution. We have therefore conducted an in vitro study of haemodilution of human whole blood using lactated Ringer's solution and two high molecular weight hetastarches, one in a balanced salt solution, the other in a 0.9% saline solution. The thrombelastograph, commonly used for the assessment of the coagulation effects of synthetic colloids, was used as the coagulation assessment device. Serial haemodilution with hetastarch in a balanced salt solution demonstrated a biphasic response (of r-times and k-times, as well as alpha angles), with haemodilution in the 20-40% range causing enhanced coagulation, and higher degrees of dilution causing a decrease in overall coagulation performance. A similar picture was observed with lactated Ringer's solution, but only significantly so in alpha angles. Hetastarch in saline did not display this initial increased coagulability at mild to moderate dilutions. This biphasic response of lactated Ringer's solution and hetastarch in a balanced salt solution reflects the complex interaction of fluids and the coagulation system, and that these effects cannot be attributed to simple haemodilution. On the other hand, there was a linear decrease in maximum amplitude with haemodilution. Maximum amplitude was particularly affected by both starches, which is an expected finding in view of the known interaction between the hydroxyethyl starches and von Willebrand's factor.     

The treatment of burn shock: results of a 5-year randomized,controlled clinical trial of Dextran 70 v. Ringer lactate solution

Whether colloid mixtures or exclusively electrolyte solutions should be preferred for treatment of burn shock has been a topic of discussion for many years. The burns unit in Copenhagen has run a randomized, controlled trial, during the 5-year period 1971-5, in which every even-numbered patient was treated with Dextran 70 and every odd-numbered patient with Ringer lactate. Each group comprised 86 patients. The manner in which the two patient groups respond to treatment is essentially different. The characteristic features of the Dextran group are the relatively small quantities of fluid and sodium administered, the moderate hourly diuresis, the lack of haemoconcentration and reduced sodium uresis during the days subsequent to institution of shock treatment. Patients treated with Ringer lactate, on the contrary, receive more fluid and sodium, the hourly diuresis will be larger, but in spite of this these patients tend to haemoconcentrate to a considerable degree. The sodium uresis is normal all the time. Thus, these two methods of treatment create entirely different pathophysiological conditions. The weight of the patients treated with Ringer lactate is significantly greater than that of those treated with Dextran 70, but there is no difference in the extent of the burn either in square metres or in the percentage of body surface burned. A comparison is therefore permissible. The 86 patients treated with Dextran 70 had a calculated mortality of 29·9 according to Bull and Fisher (1954) and an actual mortality of 18. The 86 patients treated with Ringer lactate had an expected mortality of 32·5 and an actual mortality of 16. No statistically significant difference in mortality is to be found between the two groups. The authors consequently conclude that Ringer lactate is to be preferred to Dextran 70 because it is simpler to dose; dosing instructions do not lead to misinterpretation, treatment rarely needs to be adjusted and it is practically impossible to give an overdose.     

Hemodynamic effects of synchronized high-frequency jet ventilation compared with low-frequency intermittent positive-pressure ventilation after myocardial revascularization

BACKGROUND: The purpose of this prospective study was to examine the effect on cardiac performance of selective increases in airway pressure at specific points of the cardiac cycle using synchronized high-frequency jet ventilation (sync-HFJV) delivered concomitantly with each single heart beat compared with controlled mechanical ventilation in 20 hemodynamically stable, deeply sedated patients immediately after coronary artery bypass graft. METHODS: Five 30-min sequential ventilation periods were used interspersing controlled mechanical ventilation with sync-HFJV twice to control for time and sequencing effects. Sync-HFJV was applied using a driving pressure, which generated a tidal volume resulting in gas exchanges close to those obtained on controlled mechanical ventilation and associated with the maximal mixed venous oxygen saturation. Hemodynamic variables including cardiac output, mixed venous oxygen saturation and vascular pressures were recorded at the end of each ventilation period. RESULTS: The authors found that in 20 patients, hemodynamic changes induced by controlled mechanical ventilation and by sync-HFJV were similar. Cardiac index did not change (mean +/- SD for controlled mechanical ventilation: 2.6 +/- 0.7 l x min(-1) x m(-2); for sync-HFJV: 2.7 +/- 0.7 l x min(-1) x m(-2); P value not significant). This observation persisted after stratification according to baseline left-ventricular contractility, as estimated by ejection fraction. CONCLUSIONS: The authors conclude that after coronary artery bypass graft, if gas-exchange values are maintained within normal range, sync-HFJV does not result in more favorable hemodynamic support than controlled mechanical ventilation. These findings contrast with the beneficial effects of sync-HFJV, resulting in marked hypocapnia, on cardiac performance observed in patients with terminal left-ventricular failure.     

Hemodynamic effects of DBcAMP in patients with low cardiac output syndrome following open-heart surgery

Hemodynamic effects of DBcAMP given at 0.05 to 0.3 mg/kg/min for 30 minutes to patients with low cardiac output less than 2.21/min/m2, to patients on IABP and on dopamine or dobutamine were investigated after open-heart surgery. Hemodynamic improvements were observed in cardiac index from 1.81 +/- 0.3 (mean +/- SD) to 2.56 +/- 0.401/min/m2 (p less than 0.001), stroke index from 20.5 +/- 5.2 to 26.4 +/- 5.2 ml/best/m2 (p less than 0.001). TRP decreased from 1963.8 +/- 682.8 to 1153.9 +/- 449.0 (p less than 0.001). These changes were similar to those of Groups II (3.0 greater than or equal to C1 greater than or equal to 2.21/min/m2) and of Group III (C1 greater than 3.01/min/m2). Increases were also observed in CI from 2.28 +/- 0.67 to 2.96 +/- 0.671/min/m2 (p less than 0.001) and in stroke index from 24.4 +/- 7.2 to 29.5 +/- 6.4 ml/best/m2 (p less than 0.001) and significant decreases were observed in TPR and PVR in patients receiving dopamine or dobutamine. These results strongly suggest the inotropic action of DBcAMP was independent on the beta receptor activity and could be a powerful adjunct in the treatment of low cardiac output patients on whom the dopamine or dobutamine was ineffective.     

Hemodynamic effects of fentanyl during anesthesia with 2 concentrations of enflurane

The cardiovascular effects of intravenous fentanyl were determined in eleven patients undergoing intra-abdominal surgical procedures under enflurane anaesthesia. The patients were curarized with pancuronium and ventilated with nitrous oxide (50%) in oxygen. The systemic arterial pressure (Pa) was measured by means of a left radial arterial catheter. The pulmonary artery pressure (Ppa), the pulmonary wedge pressure (Ppw), the cardiac output, the pH and blood gases of mixed venous blood were measured by means of a thermodilution Swan-Ganz catheter. Before the surgical procedure, the measurements were carried out 10 and 20 min after the administration of 0.8% enflurane, and 5 and 15 min after 5 micrograms X kg-1 intravenous fentanyl. During surgery, the measurements were repeated under 0.8% enflurane, and then after 10 and 20 min of receiving 1.6% enflurane, and 5 and 15 min after a second intravenous injection of fentanyl (5 micrograms X kg-1).(ABSTRACT TRUNCATED AT 250 WORDS)     

Superiority of acetate compared with lactate in a rodent model of severe hemorrhagic shock

Background

Recently, we have shown that the use of lactated Ringer's (LR) solution is inferior to pure Ringer's solution (RS) in treatment of severe hemorrhagic shock in rats. The present study was performed to evaluate whether this is a specific effect of lactate or also applies to another metabolizable anion, namely acetate.

Material and methods

We subjected male Wistar rats to hemorrhagic shock by dropping the mean arterial blood pressure to 25–30 mm Hg for 60 min, resuscitated with acetated Ringer's (AR) solution, LR solution, RS, or normal saline (NS) within 30 min, and further observed the animals for 180 min.

Results

Administration of AR solution prolonged median survival to 115 min compared with 50 min for resuscitation with LR solution or 85 and 90 min for NS and RS, respectively. Resuscitation with AR solution and LR solution clearly improved metabolic acidosis compared with NS and RS but tissue injury, indicated by plasma enzyme activities, was most pronounced in the LR solution group, medium in the NS and RS groups, and least in the AR solution group.

Conclusions

In severe hemorrhagic shock, resuscitation with both RS and NS is superior to administration of LR solution but initial outcome is even further improved if AR solution is used. Mere amelioration of the acid–base status by AR solution may explain its superior role compared with RS and NS but cannot be responsible for its superiority compared with LR solution. Here, direct injury by lactate has to be discussed.     

Experimental study on interdigestive migrating contractions with intestinal transection and injection of Ringer solution into intestine

The occurrence and mechanism of IMC are still not completely elucidated. Base on the conjecture of that the region of intestine and its ingredients may be concerning with the conduction mechanism of IMC, following experiment was performed by author. Small intestine was cut into two parts. Anal side was closed as blind end, and the end of oral side was sutured to colon or anal part of intestine by end to side anastomosis. Gastric fistula and intestinal fistula of the blind ending intestine were also made, and six pieces of force transducers were sutured to the serosa of the intestine in order to observe the movement of intestine. Under non-anesthesia and non-restricted condition for whole day long, Ringer solution was injected into gastric or intestinal fistula by 50 ml one shot or continuous dripped infusion of 250 ml per hour. The result is: In upper part of intestine, the appearance of IMC in oral and anal side of intestine is continuously observed. However, in lower part of intestine, the IMC of oral and anal part of intestine appeared completely independent without any continuity. And, as one shot of 50 ml of Ringer solution was injected, the conduction of IMC was suppressed but still observable, while continuously infused of 250 ml/hr, the IMC was completely disappeared.     

Hemodynamic effects of milrinone during weaning from cardiopulmonary bypass: comparison of patients with a low and high prebypass cardiac index

OBJECTIVE: To compare the hemodynamic effects of milrinone during weaning from cardiopulmonary bypass (CPB) in patients with a low pre-CPB cardiac index (CI) <2.5 L/min/m2) and in patients with a high pre-CPB CI (> or =2.5 L/min/m2). DESIGN: Prospective, randomized, double-blind study. SETTING: University hospital. PARTICIPANTS: Forty-eight patients scheduled for elective coronary artery bypass graft surgery. INTERVENTION: Patients were divided into 4 groups: (1) low pre-CPB CI/placebo, (2) low pre-CPB CI/milrinone, (3) high pre-CPB CI/placebo, and (4) high pre-CPB CI/milrinone. Patients received a loading dose of 20 microg/kg of milrinone followed by an infusion of 0.2 microg/kg/min or placebo 15 minutes before the anticipated weaning time. MEASUREMENTS AND MAIN RESULTS: In the low pre-CPB CI/ placebo group, low CIs and high systemic vascular resistances (SVRs) were observed after CPB. High doses of dopamine and dobutamine were needed, and infusion of epinephrine was used in 5 of the 12 patients for hemodynamic support. Milrinone improved CI and reduced SVR in the low pre-CPB CI/milrinone group. Norepinephrine was needed to maintain an adequate systemic blood pressure in 6 of the 12 patients, however. In the high pre-CPB CI/placebo group, satisfactory CIs and SVRs were observed during weaning from CPB with low doses of dopamine and dobutamine. Milrinone significantly increased CI and decreased SVR in the high pre-CPB CI/milrinone group: 10 of the 12 patients had CIs above the upper limit of normal, and 7 patients had SVRs below the lower limit of normal. CONCLUSION: Milrinone was effective during weaning from CPB in patients with a low pre-CPB CI. Milrinone in combination with norepinephrine was a good alternative to epinephrine for the treatment of myocardial dysfunction after CPB.     

Successful peritoneal dialysis using 0.9% sodium chloride with modified M/6 sodium lactate solution and recycled catheters

Acute peritoneal dialysis (PD) was carried out in 8 patients with renal failure (5 acute, 3 chronic) using 2.076-litre cycles of 0.9% sodium chloride (1,250 ml) plus M/6 sodium lactate (600 ml) to which 5% dextrose (170 ml), 50% dextrose (40 ml) and 10% calcium gluconate (16 ml) were added. Two acute catheters were recycled amongst all the patients after sterilisation in 5% formaldehyde. In all 8 patients, there was progressive clinical and biochemical improvement during 12-88 cycles of PD performed over 0.5-35 days. 2 patients with acute renal failure recovered completely. Another patient had prostatectomy for obstruction and a 4th subsequently received a successful kidney transplant abroad. 3 patients died, 2 of them after discharge from hospital, and 1 defaulted from follow-up. Peritonitis occurred in 2 patients. No side effects attributable to the dialysis solution were observed. However, repeated chemical treatment resulted in catheter opacification and blockage of perforations, but reperforation using a sterile needle usually restored good drainage. In poor countries with limited dialysis facilities, the use of 0.9% sodium chloride with modified M/6 sodium lactate solutions for PD and reuse of acute PD catheters are effective, safe and cost-saving.     

Better correction of metabolic acidosis, blood pressure control, and phagocytosis with bicarbonate compared to lactate solution in acute peritoneal dialysis

Lactate solution has been the standard dialysate fluid for a long time. However, it tends to convert back into lactic acid in poor tissue-perfusion states. The aim of this study was to evaluate the efficacy of magnesium (Mg)- and calcium (Ca)-free bicarbonate solution compared with lactate solution in acute peritoneal dialysis (PD). Renal failure patients who were indicated for dialysis and needed acute PD were classified as shock and nonshock groups, and then were randomized to receive either bicarbonate or lactate solution. Twenty patients were enrolled in this study (5 in each subgroup). In the shock group, there were more rapid improvements and significantly higher levels of blood pH (7.40 +/- 0.04 versus 7.28 +/- 0.05, p < 0.05), serum bicarbonate (23.30 +/- 1.46 versus 18.37 +/- 1.25 mmol/L, p < 0.05), systolic pressure (106.80 +/- 3.68 versus 97.44 +/- 3.94 mm Hg, p < 0.05), mean arterial pressure (80.72 +/- 2.01 versus 73.28 +/- 2.41 mm Hg, p < 0.05), percentages of phagocytosis of circulating leukocytes (65.85% +/- 2.22 versus 52.12% +/- 2.71, p < 0.05), and percentages of positive nitroblue tetrazolium (NBT) reduction test without and with stimulation (14.43 +/- 1.93 versus 9.43 +/- 2.12, p < 0.05 and 65.08 +/- 6.80 versus 50.23 +/- 4.21, p < 0.05, respectively) in the bicarbonate subgroup compared with the lactate subgroup. In the nonshock group, blood pH, serum bicarbonate, and phagocytosis assays in both subgroups were comparable. Lactic acidosis was more rapidly recovered and was significantly lower with bicarbonate solution for both shock and nonshock groups (3.63 +/- 0.37 versus 5.21 +/- 0.30 mmol/L, p < 0.05 and 2.92 +/- 0.40 versus 3.44 +/- 0.34 mmol/L, p < 0.05, respectively). Peritoneal urea and creatinine clearances in both subgroups were comparable for both shock and nonshock groups. There was no peritonitis observed during the study. Serum Mg and Ca levels in the bicarbonate subgroup were significantly lower, but no clinical and electrocardiographic abnormality were observed. We concluded that Mg- and Ca-free bicarbonate solution could be safely used and had better outcomes in correction of metabolic acidosis, blood pressure control, and nonspecific systemic host defense with comparable efficacy when compared to lactate solution. It should be the dialysate of choice for acute PD especially in the poor tissue-perfusion states such as shock, lactic acidosis, and multiple organ failure.     

Donor heart preservation with a novel hyperpolarizing solution: superior protection compared with University of Wisconsin solution

OBJECTIVES: A donor heart preservation solution was designed to use hyperpolarized arrest with the adenosine triphosphate-sensitive potassium-channel opener pinacidil. This solution contained concentrations of potassium, sodium, calcium, magnesium, lactobionate, and the buffer histidine specifically chosen to minimize intracellular calcium accumulation associated with prolonged ischemia. METHODS: Twenty-four rabbit hearts were randomly assigned to receive 1 of 3 preservation solutions in a crystalloid-perfused Langendorff model: (1) prototype solution containing a 0.5 mmol/L concentration of pinacidil, (2) prototype solution without pinacidil as control, and (3) University of Wisconsin solution. Thirty minutes of initial perfusion preceded baseline data acquisition. Data comprised left ventricle pressure-volume curves generated by inflating an intraventricular latex balloon. After cardioplegic administration, hearts underwent 4 hours of hypothermic storage, followed by 60 minutes of reperfusion and postischemic data acquisition. RESULTS: Postischemic developed pressure was better preserved by pinacidil solution (92.4% +/- 4.5%) than by the control (74.9% +/- 3.4%, P =.01) and University of Wisconsin solutions (66.7% +/- 5.1%, P =.001). Diastolic negative dP/dT was better preserved by pinacidil solution (104.4% +/- 10.2%) than by the control (80.2% +/- 4.2%, P =.034) and University of Wisconsin solutions (71.7% +/- 7.0%, P =.015). Diastolic compliance, expressed as baseline/postischemic diastolic slope ratios, was more poorly preserved by University of Wisconsin solution (0.67 +/- 0.07) than by the pinacidil (0.88 +/- 0.05, P =.041) and control solutions (0.87 +/- 0.05, P =.021). Postischemic coronary flow was higher in hearts exposed to pinacidil solution (77.8% +/- 3.0%) than in those exposed to the control (66.8% +/- 2.4%) and University of Wisconsin solutions (70.9% +/- 4.0%, P =.07). CONCLUSIONS: The superiority of the pinacidil solution in this experiment demonstrated that hyperpolarized arrest with potassium-channel openers improves donor heart preservation when administered in a novel histidine-buffered lactobionate-enriched vehicle.     

Effect of intraoperative acetated Ringer’s solution with 1% glucose on glucose and protein metabolism

Purpose  

To investigate the effects of the intraoperative administration of Ringer’s solution with 1% glucose on the metabolism of glucose, lipid and muscle protein during surgery.