This experimental study was performed on 5 rabbits to ascertain if oxygenated Ringer's lactate Could be used in place of fluorocarbons through peritoneal administration. Oxygen was bubbled through solutions of Ringer's lactate at two different rates and the oxygen tension of each solution was determined. The solution used in vivo had oxygen delivered at a rate of 5 L/min; the mean PO2 and pH were 575.5 mmHg and 6.34 respectively, while the rate of oxygenation of the in vitro solution was 3 L/min. with a mean PO2 and pH of 416.6 mmHg and 6.08. After peritoneal administration of the oxygenated solution the PaO2 values were significantly increased from the control value. Other parameters such as pH, PaCO2, HCO3, BE, SO2 (oxygen saturation), Na and K were not shown to be statistically significant. Some degree of oxygenation could be obtained by the introduction of oxygenated Ringer's solution. This result suggested that this solution can be used for oxygenation via the transperitoneal administration, and that this method of oxygenation may possibly be used to treat some forms of respiratory failure.
Animal ; Infusions, Parenteral ; Isotonic Solutions/administration & dosage* ; Oxygen/administration & dosage* ; Oxygen/blood ; Rabbits

This experimental work was performed on 4 rabbits to demonstrate that administrations of oxygenated Ringer's lactate through the central venous infusion could be used as a means of oxygenation. The oxygen tensions of Ringer's lactate were determined upon changing the amount of oxygen being bubbled and the solutions with the mean PO2 and pH of 575.5 mmHg and 6.34 were used in this study. We did not use the solutions having the values below 416.6 mmHg PO2 and pH 6.08. After the infusion of the oxygenated solution through central vein, PaO2 values throughout the 1 hour experimental procedure were significantly increased above the control value. Other parameters such as pH, PaCOs, HCO3-, BE, O2 saturation did not show any statistically significant changes. Some degree of oxygenation could be obtained by infusing the oxygenated Ringer's solution. This suggested that oxygenation by infusion through the central venous line could used clinically in the treatment of some forms of hypoxia with hypovolemia.
Analysis of Variance ; Animals ; Blood Gas Analysis ; Infusions, Intravenous ; Isotonic Solutions/*administration & dosage ; Oxygen/*administration & dosage ; Rabbits

OBJECTIVETo investigate the effect of hyperoxic Ringer's solution on inhalation injury given at early postburn stage in rabbit.

METHODSSeventy-seven rabbits were randomly divided into four groups, i.e. A (normal control, n = 5, without injury), B (n = 24, with Ringer's solution infusion for 10 days after injury), C (n = 24, with hyperoxic Ringer's solution infusion for 10 days after injury) and D (n = 24, without treatment after injury) groups. The rabbits in B, C and D groups were observed on 1 post injury day (PID), 2 PID, 3 PID, 5 PID, 7 PID and 10 PID, with 4 in each time points. The vital signs and survival rate were observed and the blood gas analysis, the WBC and PMN in the peripheral blood, ratio of wet/dry weight (W/D) of the lung tissue, the MDA, SOD contents in the pulmonary tissue, and the pulmonary pathomorphology were determined by corresponding methods.

RESULTSThe respiratory rate of the rabbits increased postburn, which was accompanied with gasping breath, flapping of nasal alae, frequent cough, and increased buccal and nasal secretion. Dry and wet rales were heard in the lungs after injury. The survival rate in D, B and C groups was 13.3%, 27.8% and 65.6%, respectively. Metabolic acidosis was identified in these groups by blood gas analysis. The indices of PaCO2, WBC, PMN, W/D, MDA in B, C and D groups were higher than those in A group in the order of D > B > C > A groups. While the pH, PaO2 value and SOD content in D group were lower than those in A group in the order of D < B < C < A groups (P < 0.05). Pathomorphological examination revealed that pulmonary volume increased after the injury with microscopic inflammatory changes in pulmonary tissue in B, C and D groups. While the extent and degree of injury in C group after the treatment of hyperoxic Ringer's solution were evidently less severe than those in other groups.

CONCLUSIONEarly administration of hyperoxic Ringer's solution during the early postburn stage could be beneficial to the management of inhalation injury.

Animals ; Blood Gas Analysis ; Burns, Inhalation ; therapy ; Disease Models, Animal ; Fluid Therapy ; Isotonic Solutions ; therapeutic use ; Oxygen ; administration & dosage ; Rabbits

OBJECTIVETo assess the value of an infusion-based separation technique to assist in ultrasound (US)-guided percutaneous radiofrequency ablation (RFA) of liver cancers abutting the liver edge.

METHODSTwenty-four cases of malignant liver tumors abutting the hepatic edge were treated with US-guided puncture accompanied by the assistant infusion technique. The US-guided puncture was made with a 22-G needle through the hepatic tissue and into the abdominal cavity near the target tumor. Infusion of a saline solution was used to separate the liver from any surrounding structures so that percutaneous RFA could be safely performed. Complications, including gastrointestinal injury, hemorrhage and death, were recorded. Technical efficacy and safety were evaluated.

RESULTSAmong the 24 patients, the target tumors were adjacent to the right kidney (n=6), colon (n=6), stomach (n=5), pericardium (n=4), and gall bladder (n=3). Twenty-three patients received a successful radical percutaneous RFA with assistant infusion. The assistant infusion volumes ranged from 80-390 ml and created spaces ranging from 0.8-2.5 cm between the liver and surrounding structures. Five of the cases with tumors adjacent to the stomach or colon received the largest volume infusions. The infusion failed to create a separation space in only one case, due to the presence of an adhesion; as a result, this patient was treated with palliative RFA. The mean hospital stay for all 24 patients was four days after surgery. No severe complications or deaths occurred. At 1-month follow-up, computed tomography images showed that 22 cases had complete ablation, yielding a technical success rate of 95.7% (22/23). No needle track implantation was observed.

CONCLUSIONAssistant infusion for percutaneous radiofrequency ablation creates a protective space between the liver and surrounding structures in patients with liver tumors abutting the liver edge. This safe and effective assistant technique broadens the range of patients available for percutaneous RFA treatment.

Adult ; Aged ; Carcinoma, Hepatocellular ; surgery ; Catheter Ablation ; methods ; Female ; Humans ; Isotonic Solutions ; administration & dosage ; Liver Neoplasms ; surgery ; Male ; Middle Aged ; Treatment Outcome ; Ultrasonography, Interventional

OBJECTIVETo explore the dynamic postburn changes in rat hepatic function and the effects of hyperoxic Ringer's solution resuscitation on the function.

METHODSOne hundred and ninety Wistar rats of both sexes with body weight of 250 - 300 g were employed as the model and were divided into 6 groups as A, B, C, D, E and F groups as follows: normal control (A, n = 10), early resuscitation with Ringer's solution (B, n = 40), delayed resuscitation with Ringer's solution (C, n = 30), early resuscitation with hyperoxic Ringer's solution (D, n = 40), delayed hyperoxic Ringer's solution resuscitation (E, n = 30) and burn control (F, n = 40). Blood samples were drawn from the injured rats under anesthesia at 6, 12, 24 and 48 postburn hours (PBHs), and the serum contents of ALT, AST and MDA in these blood samples were determined. Hepatic tissue samples were also harvested at the same time and served histologically.

RESULTSThe plasma ALT level at 6 PBH in all groups was higher than that in A group (P < 0.05). There was significant difference of plasma ALT levels between hyperoxic Ringer's solution treatment group an other treatment groups (P < 0.05). And there was evident difference of plasma ALT levels between hyperoxic Ringer's solution treatment groups and other treatment groups (P < 0.05). The dynamic change in plasma AST was almost similar to that of ALT. The plasma MDA level was increased obviously after injury, especially in F group (highest level). Furthermore, the MDA level in C group was higher than that in B group. The plasma MDA levels in D and E groups were evidently lower than that in all other groups (P < 0.05). It was revealed by histological examination that there were different degrees of degeneration an necrosis of hepatocytes during early postburn stage, but less so in D group.

CONCLUSIONFluid resuscitation during early postburn stage with hyperoxic Ringer's solution could inhibit the production of oxygen free radicals and blunt lipid peroxidation, and it could also enhance the host tolerance to hypoxia and prevent hepatocytes from injury, thus hepatic function was protected.

Animals ; Burns ; metabolism ; therapy ; Fluid Therapy ; Hepatocytes ; drug effects ; pathology ; Isotonic Solutions ; therapeutic use ; Liver ; metabolism ; pathology ; Oxygen ; administration & dosage ; Rats ; Rats, Wistar ; Shock, Traumatic ; metabolism ; therapy

OBJECTIVETo investigate the effects of two fluid resuscitations on the bacterial translocation and the inflammatory factors of small intestine in rats with hemorrhagic shock.

METHODSFifty SD healthy male rats were randomly divided into 5 groups (n equal to 10 per group): Group A (Sham group), Group B (Ringer's solution for 1 h), Group C (Ringer's solution for 24 h), Group D (hydroxyethyl starch for 1 h) and Group E ((hydroxyethyl starch for 24 h). A model of rats with hemorrhagic shock was established. The bacterial translocation in liver, content of tumor necrosis factor-alpha (TNF-alpha) and changes of myeloperoxidase enzyme (MPO) activities in small intestine were pathologically investigated after these two fluid resuscitations, respectively.

RESULTSThe bacterial translocation and the expression of TNF-alpha in the small intestine were detected at 1 h and 24 h after fluid resuscitation. There were significant increase in the number of translocated bacteria, TNF-alpha and MPO activities in Group C compared with Group B, significant decrease in Group E compared with Group D and in Group B compared with Group D. The number of translocated bacteria and TNF-alpha expression significantly decreased in Group E as compared with Group C.

CONCLUSIONSThe bacterial translocation and the expression of TNF-alpha in the small intestine exist 24 h after fluid resuscitation. 6% hydroxyethyl starch can improve the intestinal mucosa barrier function better than the Ringer's solution.

Animals ; Bacterial Translocation ; drug effects ; Fluid Therapy ; Hydroxyethyl Starch Derivatives ; administration & dosage ; pharmacology ; Intestine, Small ; metabolism ; Isotonic Solutions ; administration & dosage ; pharmacology ; Male ; Peroxidase ; metabolism ; Rats ; Rats, Sprague-Dawley ; Shock, Hemorrhagic ; therapy ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo investigate the potential and early effect of hypertonic saline resuscitation on T-lymphocyte subpopulations in rats with hemorrhagic shock.

METHODSA model of rat with severe hemorrhagic shock was established in 18 Sprague-Dawley (SD) rats. The rats were randomly divided into Sham group, HTS group (hypertonic saline resuscitation group) and NS group (normal saline resuscitation group). Each group contained 6 rats. The CD4(+) and CD8(+) subpopulations of T-lymphocytes in peripheral blood were detected respectively before shock and after resuscitation by double antibody labelling and flow cytometry.

RESULTSIn the early stage after hemorrhagic shock, fluid resuscitation and emergency treatment, the CD4(+) lymphocytes of peripheral blood in HTS and NS groups markedly increased. Small volume resuscitation with HTS also induced peripheral CD8(+) lymphocytes to a certain extent, whereas NS resuscitation showed no effect in this respect. Consequently, compared with Sham and HTS groups, CD4(+)/CD8(+) ratio of peripheral blood in NS group was obviously increased, and showed statistically differences.

CONCLUSIONIn this model of rat with severe hemorrhagic shock, small volume resuscitation with HTS is more effective than NS in reducing immunologic disorders and promoting a more balanced profile of T-lymphocyte subpopulations regulating network.

Animals ; Blood Pressure ; CD4-CD8 Ratio ; Disease Models, Animal ; Isotonic Solutions ; administration & dosage ; Male ; Rats ; Rats, Sprague-Dawley ; Resuscitation ; methods ; Saline Solution, Hypertonic ; administration & dosage ; Shock, Hemorrhagic ; immunology ; physiopathology ; therapy ; T-Lymphocyte Subsets ; immunology

BACKGROUND: Dexmedetomidine is a highly selective alpha2-adrenoceptor agonist that is widely used for sedation and analgesia during the perioperative period. Intravenous administration of dexmedetomidine induces transient hypertension due to vasoconstriction via the activation of the alpha2-adrenoceptor on vascular smooth muscle. The goal of this in vitro study is to investigate the calcium-dependent mechanism underlying dexmedetomidine-induced contraction of isolated endothelium-denuded rat aorta. METHODS: Isolated endothelium-denuded rat thoracic aortic rings were suspended for isometric tension recording. Cumulative dexmedetomidine concentration-response curves were generated in the presence or absence of the following inhibitors: alpha2-adrenoceptor inhibitor rauwolscine; voltage-operated calcium channel blocker verapamil (5 x 10(-7), 10(-6) and 5 x 10(-5) M); purported inositol 1,4,5-trisphosphate receptor blocker 2-aminoethoxydiphenylborate (5 x 10(-6), 10(-5) and 5 x 10(-5) M); phospholipase C inhibitor U-73122 (10(-6) and 3 x 10(-6) M); and store-operated calcium channel inhibitor gadolinium chloride hexahydrate (Gd3+; 5 x 10(-6) M). Dexmedetomidine concentration-response curves were also generated in low calcium concentrations (1 mM) and calcium-free Krebs solution. RESULTS: Rauwolscine, verapamil, and 2-aminoethoxydiphenylborate attenuated dexmedetomidine-induced contraction in a concentration-dependent manner. Low calcium concentrations attenuated dexmedetomidine-induced contraction, and calcium-free Krebs solution nearly abolished dexmedetomidine-induced contraction. However, U-73122 and Gd3+ had no effect on dexmedetomidine-induced contraction. CONCLUSIONS: Taken together, these results suggest that dexmedetomidine-induced contraction is primarily dependent on extracellular calcium concentrations that contribute to calcium influx via voltage-operated calcium channels of isolated rat aortic smooth muscle. Dexmedetomidine-induced contraction is mediated by alpha2-adrenoceptor stimulation. Dexmedetomidine-induced contraction appears to be partially mediated by calcium release from the sarcoplasmic reticulum.
Administration, Intravenous ; Analgesia ; Animals ; Aorta ; Calcium ; Calcium Channels ; Contracts ; Dexmedetomidine ; Estrenes ; Gadolinium ; Hypertension ; Inositol 1,4,5-Trisphosphate ; Isotonic Solutions ; Muscle, Smooth ; Muscle, Smooth, Vascular ; Perioperative Period ; Pyrrolidinones ; Rats ; Sarcoplasmic Reticulum ; Type C Phospholipases ; Vasoconstriction ; Verapamil ; Yohimbine