Intraperitoneal Ketamine Research Articles

Neuroprotective Effects of Ginkgo Biloba Extract on Bilateral Common Carotid Artery Ischaemic Stroke Induced in Wistar Rat

Stroke is one of the most prevalent vascular diseases in the world and has persistently ranked as at least the third leading cause of death globally over the past few decades (WHO). Ginkgo biloba extract (GBE) contains flavonoids and ginkgolides making it a promising anti-oxidative natural product. The aim was to evaluate neuroprotective effects of GBE on hippocampus and cerebrum of Wistar rat with acute ischaemia induced by the bilateral common carotid artery occlusion (BCCAO).Thirty adult male Wistar rats were randomly assigned to 5 study groups (n=6) and acclimatized in clean cages for a week. Group A, received Normal saline, Group B received GBE only, Group C had BCCAO only, Group D received GBE presurgery, and Group E received GBE postsurgery. The safe oral GBE daily dose of 100 mg/kg/day was administered for 14 days. 2 rats shared 1 capsule per day at average weight of 200 grams. Giloba, the soft gel capsule used, was manufactured by Mega Life Sciences Nigeria Ltd.: NAFDAC Reg. No. A7-0404L. After adequate anaesthesia at 80-100mg/kg of intraperitoneal Ketamine, BCCAO was performed with 3/o silk suture ligation. Reperfusion was allowed after 30 minutes. Analgesia and antibiotic prophylaxis were with intramuscular paracetamol injection and topical penicillin cream. Neurobehavioral changes in spatial exploration was assessed using Y-Maze toolkit. On day 21, from onset of acclimatization, the rats were sacrificed by gentle cervical dislocation under mild anaesthesia and the whole brain harvested for histomorphological studies.GBE offered neuroprotection as evidenced by remarkably less pyknotic cells and perineuronal vacuolations in the brain tissue with prophylactic effect being more pronounced than therapeutic action. It also boosted spatial working memory in the rats.

Is bladder outlet obstruction rat model to induce overactive bladder (OAB) has similarity to human OAB? Research on the events in smooth muscle, collagen, interstitial cell and telocyte distribution

BackgroundCellular and cytoskeletal events of overactive bladder (OAB) have not been sufficiently explored in human bladder due to different limitations. Bladder outlet obstruction (BOO) had been induced in different animal models with different methods to induce (OAB). Similarity of the animal models of BOO to the human OAB is postulated but has not been confirmed. The interstitial cells of Cajal (ICCs), and telocytes (TCs) are an important players in smooth muscles conductivity, they had not been well investigated in the previous BOO models. Objectives are to investigate the morphological pattern of cellular, cytoskeleton and telocytes distribution in BOO rat model and to match the events in two time periods and compare it to the findings in real-world human OAB.MethodsFemale Sprague-Dawley rats (Rattus norvegicus) were randomly divided into: sham (n = 10), BOO 6 W (n = 10), BOO 8 W (n = 10). Operative procedure to Induce BOO was done under anesthesia with intraperitoneal Ketamine administration. The Effect of induction of BOO was evaluated after 6 and 8 weeks. The rats were anesthetized, and the urinary bladder was removed, while the rat was unconscious under anaesthesia it was transferred to the inhalation anaesthesia cage for euthanasia, rats were sacrificed under light anesthesia using isoflurane. Care of animals, surgical procedure, and euthanasia adhered to Guide for the Care and Use of Laboratory Animals, and AVMA Guidelines for the Euthanasia of Animals. The retrieved bladder was processed for examination with histopathology, immunohistochemistry (IHC), and transmission electron microscopy (EM).ResultsHistological examination of the bladder shows thinner urothelium, condensation of collagen between muscle bundles. IHC with c-kit shows the excess distribution of ICCs between smooth muscle bundles. EM shows frequent distribution of TCs that were situated between collagen fibers. Finings in BOO 6 W group and BOO 8 W group were comparable.ConclusionThe animal model study demonstrated increased collagen/ smooth muscle ratio, high intensity of ICCs and presence of TCs. Findings show that a minimally invasive procedure to induce BOO in rats had resulted in an OAB that has morphological changes that were stable in 6 & 8 weeks. We demonstrated the distribution of TCs and ICCs in the rat animal model and defined them. The population of TCs in the BOO rat model is described for the first time, suggests that the TCs and ICCs may contribute to the pathophysiology of OAB. Similarity of animal model to human events OAB was demonstrated. These findings warrant further study to define the role of TCs in OAB.Clinical trial registryThe study does not require a clinical trial registration; it is an experimental animal study in basic science and does not include human subjects.

Effects of Nostoc commune extract on the cerebral oxidative and neuroinflammatory status in a mice model of schizophrenia

Cyanobacterium Nostoc commune has long been used to alleviate various diseases. This research examines the effects of Nostoc commune extract (NCE) against behavioral disorders, cerebral oxidative stress, and inflammatory damage in the ketamine-induced schizophrenia model. Oral NCE administration (70 and 150 mg/kg/d) is performed after intraperitoneal ketamine injection (20 mg/kg) for 14 consecutive days. The forced swimming and open field tests are used to assess schizophrenia-like behaviors. After the behavioral test, dopamine (DA) level, oxidative stress markers, as well as the interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) expression are measured in the cerebral cortex. The results show that NCE treatment ameliorates KET-induced anxiety and depressive-like behaviors in OFT and FST, respectively. NCE considerably decreases the malondialdehyde (MDA) and DA levels and IL-6 and TNF-α expressions in mice with schizophrenia-like symptoms. Also, a significant increase is observed in the glutathione (GSH) level and catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GRx) activity in cerebral tissue. The present study shows that NCE treatment effectively improves KET-induced schizophrenia-like behaviors and oxidative and inflammatory damage. Therefore, NCE, via its bioactive constituents, could have strong neuroprotective effects in the schizophrenia-like model.

Nebulized and intraperitoneal ketamine have equivalent antidepressant-like effect in the forced swim and tail suspension tests in mice

Major depressive disorder (MDD) is a debilitating illness that affects millions of people worldwide. Currently available antidepressants often take weeks to months to reach their full effect, which leads to an increased risk of suicidal behavior in patients with MMD. Intranasally, esketamine has emerged as an alternative to current antidepressants because of its rapid onset and long-lasting effects in patients with MDD. Animal models are useful for the initial pharmacological screening and for a better understanding of the mechanisms underlying the effects of new drugs with potential against MDD. There is a lack of data on alternative routes of drug administration, either oral or injectable, that can be used in preclinical studies. This study aimed to test whether ketamine has antidepressant-like effects in mice when administered via nebulization using a low-cost apparatus. When mice whose depressive-like behavior was induced by corticosterone were treated with nebulized ketamine at concentrations of 1.3, 2.6, and 5.2 mg/mL, immobility was reduced by 38.6 %, 62.0 %, and 61.1 %, respectively, in the forced swimming test (FST) and 43.6 %, 42.1 %, and 57.9 %, respectively, in the tail suspension test (TST). When depression-like behavior was induced by dexamethasone, nebulization with ketamine reduced immobility by 79.7 %, 49.2 %, and 44.4 % in the FST and 80.9 %, 71.4 %, and 80.4 %, respectively, in the TST. When depression-like behavior was induced by the association between dexamethasone and unpredictable chronic mild stress (UCMS) exposure, immobility was reduced by 26.1 %, 55.3 %, and 19.1 % in FST. Mice treated with nebulized ketamine did not show significant changes in the distance covered or in the time spent moving in the open field test. The efficacy of intraperitoneal and nebulized ketamine is equivalent, which shows that nebulization can be an alternative inexpensive route of drug administration for behavioral studies in rodents.

128 NMDA-Receptor Antagonism for the Prevention of Neurological Dysfunction in Traumatic Brain Injury: Results of a Randomized Pre-Clinical Trial

INTRODUCTION: Cortical spreading depolarization (CSD) represents a pathomechanistic target for neuroprotective therapy given the association with lesion development and poor outcomes following traumatic brain injury (TBI). METHODS: Experiments were conducted using 9-week-old Sprague Dawley rats. Daily neurobehavioral scores were recorded by trained, blinded observers. Using an established weight-drop model, animals received either single moderate (modTBI; n = 23) or four daily mild (rmTBI; n = 30) head impacts. Sham animals received brief anesthetic without TBI (n = 40). Animals underwent cranial window surgery and CSDs were electrically triggered by cortical stimulation; electrophysiological, imaging and blood-flow were monitored using intravital microscopy. Ketamine (100uM topical and 25 mg/kg IP, respectively) and memantine (10 mg/kg IP) were tested in vivo. Subsequently, a RCT was conducted (N=31) using memantine (10 mg/kg) or saline (2.5 cc/kg). Primary outcome: proportion of animals resilient to rmTBI (neurobehavioral scores ≥ 6 out of 12). RESULTS: In modTBI, and rmTBI animal models, intraperitoneal ketamine and memantine reduced the proportion of electrically triggered CSDs by 79-88%, and 42-73%, respectively. The average relative amplitude of change in ECoG were reduced by 70-75%, and 51-60%, respectively. Memantine significantly reduced spreading depression and cortical hypoperfusion following CSD. RCT animals in the memantine group were more likely resilient to injury (93% vs. 56%; p = 0.023) and had higher mean neurological scores (9.27 (SD 3.08) vs. 5.56 (SD 3.05)), p < 0.001) compared to saline. CONCLUSIONS: The NMDA-receptor antagonist memantine supresses CSDs and reduces pathological cerebral hypoperfusion in vivo following CSDs. In a rmTBI RCT, memantine prevented neurological decline.

Pseudomonas aeruginosa Keratitis in Rats: Study of the Effect of Topical 5% Hesperidin Practice on Healing.

The aim of this study is to investigate the effect of topical 5% hesperidin application on healing. After 48 rats were randomized and divided into 7 groups, on the first day, an epithelial defect was created in the center of the cornea with the help of microkeratome under intraperitoneal ketamine+xylazine and topical 5% proparacaine anesthesia for the groups to be infected with keratitis according to the groups mentioned below. An amount of 0.05 mL of the solution containing 108 colony-forming units/ mL Pseudomonas aeruginosa (PA-ATC27853) will be taken and inoculated per rat. At the end of the 3 days incubation period, rats with keratitis will be added to the groups, and active substances and antibiotics will be given topically together with other groups for 10 days. At the end of the study, the ocular tissues of the rats will be removed and examined histopathologically. A clinically significant reduction in inflammation was detected in the groups using hesperidin. No transforming growth factor-β1 staining was detected in the group in which keratitis+hesperidin was treated topically. In the group in which hesperidin toxicity was examined, mild inflammation and thickening of the corneal stroma layer were observed, and it was evaluated as a negative transforming growth factor-β1 expression in the lacrimal gland tissue. Corneal epithelial damage was minimal in the keratitis group, and the toxicity group was treated with only hesperidin when compared to the other groups. Topical hesperidin drops may be an important therapeutic factor in tissue healing and in the fight against inflammation in the treatment of keratitis.

Ketamine Inhalation Alters Behavior and Lower Urinary Tract Function in Mice.

We aimed to evaluate behavioral and lower urinary tract changes in mice using a novel ketamine inhalation model mimicking human ketamine abusers and compare the results to those obtained using a ketamine intraperitoneal injection model. C57BL/6N mice were placed in a transparent acrylic observation cage connected to an ultrasonic nebulizer producing ketamine (KI) or saline (SI) fog. The mice were given KI or SI fog twice a week for three months. In another experiment arm, the mice were given intraperitoneal ketamine injections (KP) or saline injections (SP) twice a week for three months. The presence of urine ketamine (>100 ng/mL) was determined using a quick test kit. Locomotor activity was recorded by video using the open field test. Lower urinary tract function was assessed using urine spots, cystometry and histology. KI and KP mice crossed the center more frequently and traveled farther than SI and SP mice. Only KI mice, however, demonstrated popcorn-like jumping, and frequent center crossing. Detrusor overactivity, reduced cystometric bladder capacity, and denuded mucosa were observed in both KI and KP mice. Ketamine inhalation induces behavioral and lower urinary tract changes in mice that are comparable to intraperitoneal ketamine injections.

The effect of intraperitoneal ketamine, dexmedetomidine and bupivacaine on postoperative pain control in patients undergoing abdominal hysterectomy

The effect of intraperitoneal ketamine, dexmedetomidine and bupivacaine on postoperative pain control in patients undergoing abdominal hysterectomy

Experimental research in rats on the reactivity of new corneal blood vessels to adrenaline.

Aim: The purpose of this experimental study was to evaluate the existence of adrenergic receptors in ketamine-induced corneal blood vessels in rat pups. Methods: The study of corneal neovascularization motricity was performed on 45-day-old Wistar rats in which, starting from the 15th day of life, corneal blood vessels were obtained by injecting intraperitoneal ketamine at a dose of 150 mg/ kg body weight, a total of 5 successive doses. The examination of the neovascularization was done with the help of a Nikon stereomicroscope connected to a video camera and a computer, the total magnification being 400X. The reactivity of the new corneal blood vessels to the administration in conjunctival instillations of a 1.5 mmol/L adrenaline solution was tested. The parameters followed were represented by variations in the caliber of corneal blood vessels. The data were analyzed using Microsoft Office Excel.Results: Administration of distilled water did not produce statistically significant changes in corneal blood vessels, while adrenaline produced a statistically significant constriction of vascular diameter (p=0.01 at T9, p=0.004 at T10, p=0.019 at time T11 of examinations).Conclusions: The results showed that adrenaline produces vasoconstriction in the new corneal blood vessels, which allows us to assume that they contain α-adrenergic receptors. However, we cannot say that corneal pathological vessels do not contain β2-type adrenergic receptors, because the effect of adrenaline may be an algebraic sum between vasoconstriction produced by stimulating α-adrenergic receptors and vasodilation produced by stimulating β2-adrenergic receptors, but in which the vasodilating effect may be masked by the vasoconstrictor effect given by a higher density of α-adrenergic receptors.Abbreviations: A= adrenaline, DNM = non-measurable diameter, NA= noradrenaline, Std.Er.= Standard error

Hypolipemiant Actions and Possible Cardioprotective Effects of Valine and Leucine: An Experimental Study

Background and Objectives: Considering atherosclerosis as one of the more challenging threats to healthcare worldwide, any novel therapy that counteracts the risks for developing it, provides new opportunities for the management of this process. Material and methods: We performed an experimental research in which we induced a hypercholesterolemia via a cholesterol-rich diet. Our aim was to demonstrate the antiatherogenic potential of two essential amino acids (valine and leucine). The experimental study was carried out over a period of 60 days. Male Wistar rats weighing between 250–280 g were used and divided into 4 groups, each group including 8 animals. Group I—control was fed with a standard diet. Group II received cholesterol, group III cholesterol and valine and group IV cholesterol and leucine. Blood samples were collected from the retro-orbital plexus, under anesthesia with 75 mg/kg of intraperitoneal ketamine, in three different moments (R0—1st day, R1—the 30th day, R2—the 60th day) in order to measure the levels of triglycerides. Results: In R0, there were no significant differences between the average levels of triglycerides across all the groups (p < 0.05). Compared to the group I, in R1 and R2, the average levels of triglycerides were significantly higher in all groups (p < 0.001). Also, in R1 and R2, the average triglycerides in group II receiving cholesterol (C) were significantly higher than those in group III receiving valine (C + V) as well as in group IV receiving leucine (C + L) (p < 0.001; p < 0.05). In R2, the average triglycerides in group III were significantly lower than in group IV (p < 0.001). Conclusions: Our data provides evidence that valine and leucine have a direct impact on the lipid metabolism parameters by lowering the level of triglycerides. The comparison of the two essential amino acids indicates that valine acts more promptly and rapidly than leucine.

Differential effect of anesthetics on mucociliary clearance in vivo in mice

Respiratory mucociliary clearance (MCC) is a key defense mechanism that functions to entrap and transport inhaled pollutants, particulates, and pathogens away from the lungs. Previous work has identified a number of anesthetics to have cilia depressive effects in vitro. Wild-type C57BL/6 J mice received intra-tracheal installation of 99mTc-Sulfur colloid, and were imaged using a dual-modality SPECT/CT system at 0 and 6 h to measure baseline MCC (n = 8). Mice were challenged for one hour with inhalational 1.5% isoflurane, or intraperitoneal ketamine (100 mg/kg)/xylazine (20 mg/kg), ketamine (0.5 mg/kg)/dexmedetomidine (50 mg/kg), fentanyl (0.2 mg/kg)/1.5% isoflurane, propofol (120 mg/Kg), or fentanyl/midazolam/dexmedetomidine (0.025 mg/kg/2.5 mg/kg/0.25 mg/kg) prior to MCC assessment. The baseline MCC was 6.4%, and was significantly reduced to 3.7% (p = 0.04) and 3.0% (p = 0.01) by ketamine/xylazine and ketamine/dexmedetomidine challenge respectively. Importantly, combinations of drugs containing fentanyl, and propofol in isolation did not significantly depress MCC. Although no change in cilia length or percent ciliation was expected, we tried to correlate ex-vivo tracheal cilia ciliary beat frequency and cilia-generated flow velocities with MCC and found no correlation. Our results indicate that anesthetics containing ketamine (ketamine/xylazine and ketamine/dexmedetomidine) significantly depress MCC, while combinations containing fentanyl (fentanyl/isoflurane, fentanyl/midazolam/dexmedetomidine) and propofol do not. Our method for assessing MCC is reproducible and has utility for studying the effects of other drug combinations.

Investigation of Analgesic Minimum Effective Dose of Apelin‐13 With Different Doses of Intraperitoneal Injections and its Effects on Kidney Tissue

Background and AimsApelin and APJ form a signaling pathway and are widely expressed in a variety of tissues including the heart, kidney and vessels. Apelin and APJ have various effects in many systems such as regulation of blood pressure and vascular tone, cardiac contractility, nociception, heart rate, apoptosis, inflammation. Apelin‐13 has a potential analgesic and proanalgesic effect, although the sites of analgesic effects are uncertain and controversial in terms of results. The fact that apelin can be used as a protective and therapeutic agent in the future will make important contributions both for human health and economically. The aim of the study is to investigate the analgesic minimum effective dose of Apelin‐13 with different doses of intraperitoneal application and its effects on kidney tissue.MethodsThirty Wistar Albino male rats were randomly divided into 5 groups. Rats were designated as control, Apelin‐25, Apelin‐50, Apelin‐100 and Apelin‐200 groups. Apelin‐13 was administered intraperitoneally at 25, 50, 100 and 200 μg/kg doses. The same volume of saline was administered intraperitoneally to the control group. Hot plate test was performed to evaluate analgesic efficacy at 0 and 30 minutes, 1 and 2 hours after administration. All rats were euthanized 24 hours after administration by intraperitoneal ketamine 100 mg/kg. Renal tissues were removed without traumatization and sent to the laboratory for evaluation of histological and oxidant status.ResultsIn the hot plate test, application of apelin 50 μg/kg and above had significantly more analgesic effects than the control group. 25 μg/kg apelin application was found to have no analgesic effect. When kidney tissues were examined, at the doses of 200 μg/kg Apelin; vascular vacuolization and hypertrophy, bowman dilatation and tubular cell shedding were significantly increased but not at the control group, 25 and 50 μg/kg Apelin groups (Figure 1– 2). When the oxidative status was evaluated with TAS and TOS, 200 μg/kg Apelin increased the oxidant parameters while reducing the antioxidant parameters. There was no significant change below this dose. It was also correlated with histopathological findings.ConclusionThat seems to be the first study on the analgesic effects of apelin in different doses in the literatüre and 50 μg/kg apelin is the minimum analgesic effective dose. The administration of 200 μg/kg apelin‐13 adversely affected kidney tissue histologically and tissue oxidative stress parameters increase by the high doses. Other aspects of these findings, including clinical significance and practical applications, merit further experimental and clinical investigation.Support or Funding InformationThis study was conducted in the GUDAM Laboratory of Gazi University with the consent of Experimental Animals Ethics Committee of Gazi University with the code G.U.ET‐19.024. The study was supported by Gazi University Scientific Research Committee (Scientific Research Project No. 01/2019‐44).Control group, renal tissue (10X H&amp;E)Figure 1200 μg/kg application of Apelin 13 increased vascular vacuolization and hypertrophy, bowman dilatation and tubular cell shedding (10X H&amp;E)Figure 2

Dietary zinc supplement militates against ketamine-induced behaviours by age-dependent modulation of oxidative stress and acetylcholinesterase activity in mice.

The potential differential modulatory effects of zinc-supplemented diet on ketamine-induced changes in behaviours, brain oxidative stress, acetylcholinesterase activity, and zinc (ZN) levels were examined in prepubertal and aged mice. Aged and prepubertal mice were divided into 2 groups consisting of 80 aged and 80 prepubertal mice, each having 8 treatment groups of 10 animals each. The treatment groups are: vehicle control group (fed standard diet and given intraperitoneal {ip} normal saline), three groups fed ZN-supplemented diet (at 25, 50 and 100mg/kg of feed) and given ip normal saline, ketamine control group (fed standard diet and given ip ketamine), and finally another three groups fed ZN-supplemented diet (at 25, 50 and 100mg/kg of feed) and given ip ketamine. Intraperitoneal normal saline (at 2ml/kg/day) or ketamine (at 30mg/kg/day) were administered during the last 10days of study. On day 60, animals were exposed to the open-field, Y-maze, radial-arm maze, and elevated plus maze following which they were euthanised; blood and brain homogenate were used for assessment of biochemical parameters. Zinc supplementation was associated with an increase in food intake and body weight (in both age groups), a reduction in ketamine-induced increase in locomotion, rearing and grooming, and significantly higher working-memory scores (compared to ketamine control). Also, there was a decrease in anxiety-related behaviours, enhanced antioxidant status, reduced lipid peroxidation, and reduced acetylcholinesterase activity. In conclusion, dietary ZN supplementation was associated with variable degrees of prevention of ketamine-induced changes, depending on the age of animals.

Microvenous anastomosis: The rat tail model alternative

Background: The rat femoral vein and dorsal penile vein have been have been well described as microvenous models. We report the use of the rat tail lateral vein as model for microvenous anastomosis training. Methods: Careful anatomic dissections were made of the rat tail noting the basic gross anatomy in 3 rats. 20 albino rats were anaesthesized via intraperitoneal ketamine injection, lateral vein of the tail is then transected about 5 cm distal to the tail base. Immediate repair was carried out by standard interrupted microanastomosis suture technique with 10/0 nylon suture. Patency was assessed at 30 minutes and 1 week. Results: 40 consecutive anastomosis of the lateral tail vein was done in 20 rats . The mean diameter of the rat tail lateral vein in the study rats was 0.8mm SD± 0.02mm.The mean anastomosis time was 22.6 minutes SD±4.3 minutes from clamp application to removal. There was a 90% patency rate at 30 minutes and 81 % at 1 week. Conclusion: The rat lateral tail vein appears to be a viable alternate model for microvenous anastomosis. The study identifies the ease of access, duality, potentially long length and the absence of accompanying artery as some of the unique features of this microvenous anastomosis practice model.

Influence of galantamine on peripheral nerve degeneration after experimental compression injury of the rat sciatic nerve.

Galantamine is well-known for its neuroprotective effects and is currently used in the treatment of individuals with Alzheimer's disease. In this study, we induced experimental sciatic nerve injury (SCI) in rats to test the beneficial effects of galantamine. Thirty male Wistar albino rats were divided into three groups, as follows: sham, SCI + saline, and SCI + galantamine. After the administration of an intraperitoneal ketamine and xylazine mixture, which was used for anesthesia, SCI was induced by sur-gical clip compression at the midthigh region of the rats. After surgery, a single daily intraperitoneal dose of galantamine was adminis-tered for 7 days, and nerve tissue sections were obtained 1 week after injury. Histopathology studies were performed to assess neural thickness and apoptotic cell counts, and light microscopic morphological examination was used to determine a potential beneficial effect of galantamine on peripheral nerve degeneration. We observed a markedly increased microvasculature, increased nerve fiber thickness, and a statistically significant increase in apoptotic cell counts distal to the level of injury in the saline group compared with the sham group. However, the increases in nerve fiber thickness and apoptotic cell counts were less in the galantamine group compared with the saline group. In our experimental model, pharmacological intervention with galantamine demonstrated a protective effect on degeneration after peripheral nerve injury.

Abstract 120: Effects of Therapeutic Hypothermia on Blood Parameters in Rats With Acute Hemorrhagic Shock

Background: Our research group recently observed that therapeutic hypothermia (TH) compared with normothermia improved long-term survival in an experimental model of hemorrhagic shock. The effect of TH on blood counts, blood gases and chemistries during the early phase of recovery from hemorrhagic shock are unknown. Therefore, the purpose of the present study was to examine the effects of TH on blood parameters in the early phase of resuscitation from hemorrhagic shock. Methods and results: Sprague Dawley rats (both genders) were randomly assigned to TH (n= 16) or normothermia group (n= 15). Rats were anesthetized with intraperitoneal ketamine and xylazine. After heparinizing, hemorrhagic shock was induced by withdrawing blood to a fixed mean blood pressure (MBP) of 30 mmHg for 30 minutes and then shed blood was reinfused. TH was started 5 minutes after MBP reached 30 mmHg. Core temperature was maintained at ~ 32 °C until blood volume was fully restored, after which the rats were allowed to warm back to normal temperature. In the normothermia group, body temperature was maintained at ~ 37°C. Arterial blood samples were collected 1 hour after resuscitation with shed blood. We found that pO2 (partial pressure of oxygen) was significantly higher in TH group versus the normothermic group. The rats in normothermic group had significantly elevated potassium, chloride and lactate levels and more negative base excess compared to rats that in TH group (Table). The neutrophil was lower in the TH group; the lymphocyte (%) was higher in the TH group. There were no significantly differences in pH, pCO2, sodium, calcium or glucose between the normothermia and TH groups. Conclusions: pO2 remained normal and levels of potassium, chloride, lactate and neutrophil were lower in TH group. These results may contribute to the protective effect of TH during hemorrhagic shock.

Abstract 218: Therapeutic Hypothermia Alone and Combination With Preconditioning Blunt Inflammation in Experimental Hemorrhagic Shock

Background: Recent studies by our group indicate that preconditioning, therapeutic hypothermia (TH) and TH combined with preconditioning improved long-term survival during resuscitation of hemorrhagic shock. The neutrophil-to-lymphocyte ratio (NLR) is a marker of inflammation associated with increased mortality in patients with severe hemorrhage shock. The aim of this study is to evaluate the effects of these three therapies on NLR level in rats with acute hemorrhagic shock. Methods and Results: In the preconditioning study, Sprague Dawley rats (both genders) were randomized to preconditioning (n=26) or control group (n=27); in the hypothermia study, rats were randomized to TH (n=16) or control group (n=15); in a combination study, rats were randomized to TH plus preconditioning (n=11) or control group (n=10). Rats were anesthetized with intraperitoneal Ketamine and xylazine. After heparinizing, hemorrhagic shock was induced by withdrawing blood to a fixed mean blood pressure (MBP) of 30 mmHg for 30 minutes and then shed blood was reinfused. Preconditioning was induced by 4 cycles of inflating small cuffs around the femoral arteries to 200 mmHg for 5 minutes, followed by 5-minute deflation of the cuffs prior to hemorrhagic shock. TH started at 5 minutes after MBP reached 30 mmHg. Core temperature was maintained at ~32 °C until blood volume was fully restored. In the control group, body temperature was maintained at ~ 37°C. Arterial blood samples were collected 1 hour after resuscitation. The NLR is an easily accessible biomarker, which is calculated by dividing the absolute neutrophil count by the absolute lymphocyte count. The NLR was significantly lower in TH group (0.20 ± 0.02) compared with the control group (0.32 ± 0.03; p=0.003). Similarly, the NLR level was significantly decreased in TH plus preconditioning group (0.19 ± 0.02) versus the control group (0.33 ± 0.02; p= 0.001). There was no difference in NLR level between the preconditioning group (0.41 ± 0.04) and the control group (0.41 ± 0.04; p=0.984). Conclusions: NLR is widely recognized inflammation marker associated with poor prognosis in severe hemorrhagic shock. TH alone and TH combined with preconditioning blunt the inflammation by decreasing the NLR level in experimental hemorrhagic shock.

Breathing under Anesthesia: A Key Role for the Retrotrapezoid Nucleus Revealed by Conditional Phox2b Mutant Mice.

Optimal management of anesthesia-induced respiratory depression requires identification of the neural pathways that are most effective in maintaining breathing during anesthesia. Lesion studies point to the brainstem retrotrapezoid nucleus. We therefore examined the respiratory effects of common anesthetic/analgesic agents in mice with selective genetic loss of retrotrapezoid nucleus neurons (Phox2b mice, hereafter designated "mutants"). All mice received intraperitoneal ketamine doses ranging from 100 mg/kg at postnatal day (P) 8 to 250 mg/kg at P60 to P62. Anesthesia effects in P8 and P14 to P16 mice were then analyzed by administering propofol (100 and 150 mg/kg at P8 and P14 to P16, respectively) and fentanyl at an anesthetic dose (1 mg/kg at P8 and P14 to P16). Most mutant mice died of respiratory arrest within 13 min of ketamine injection at P8 (12 of 13, 92% vs. 0 of 8, 0% wild type; Fisher exact test, P < 0.001) and P14 to P16 (32 of 42, 76% vs. 0 of 59, 0% wild type; P < 0.001). Cardiac activity continued after terminal apnea, and mortality was prevented by mechanical ventilation, supporting respiratory arrest as the cause of death in the mutants. Ketamine-induced mortality in mutants compared to wild types was confirmed at P29 to P31 (24 of 36, 67% vs. 9 of 45, 20%; P < 0.001) and P60 to P62 (8 of 19, 42% vs. 0 of 12, 0%; P = 0.011). Anesthesia-induced mortality in mutants compared to wild types was also observed with propofol at P8 (7 of 7, 100% vs. 0 of 17,7/7, 100% vs. 0/17, 0%; P < 0.001) and P14 to P16 (8 of 10, 80% vs. 0 of 10, 0%; P < 0.001) and with fentanyl at P8 (15 of 16, 94% vs. 0 of 13, 0%; P < 0.001) and P14 to P16 (5 of 7, 71% vs. 0 of 11, 0%; P = 0.002). Ketamine, propofol, and fentanyl caused death by respiratory arrest in most mice with selective loss of retrotrapezoid nucleus neurons, in doses that were safe in their wild type littermates. The retrotrapezoid nucleus is critical to sustain breathing during deep anesthesia and may prove to be a pharmacologic target for this purpose.

Effect of dexmedetomidine on ischemia-reperfusion injury of liver and kidney tissues in experimental diabetes and hepatic ischemia-reperfusion injury induced rats

Background: Reperfusion following ischemia can lead to more injuries than ischemia itself especially in diabetic patients. The aim of this study was to evaluate the effect of dexmedetomidine on ischemia-reperfusion injury (IRI) in rats with have hepatic IRI and diabetes mellitus.

Comparative evaluation of intraperitoneal bupivacaine and bupivacaine ketamine combined with lung recruitment for reducing postoperative shoulder pain in laparoscopic cholecystectomy

BackgroundShoulder pain (SP) was first reported after laparoscopic gynecological procedures. It is assumed to be multifactorial in nature. Several methods to reduce SP after laparoscopic cholecystectomy (LC) have been postulated. In this study, we have worked to decrease it using 2 approaches; lung recruitment maneuver and intraperitoneal local analgesic instillation.ObjectivesThis study was designed to assess the clinical efficacy of ketamine as an adjunct to intraperitoneal bupivacaine for the relief of post-operative shoulder pain after LC.Methods and materialThis prospective, randomized, double-blinded study is comprised of 40 patients of either sex, with age range of 20–50 years, planned for elective LC. Just after inflating the pneumoperitoneum, the surgeon sprayed 50 mL of a blinded solution intraperitoneally. Patients were randomly allocated to: group B received a 50 mL solution of intraperitoneal bupivacaine 0.25% and group BK received 0.5 mg/kg ketamine mixed with bupivacaine 0.25%.ResultsThis study showed that ketamine bupivacaine admixture had made dramatic decline in shoulder pain VAS scores specifically at the 24th hour; 15 patients in the BK group had either VAS score zero or 1 when compared to B group whom their lowest score at the 24th hour was 4. Also, there was more decrease in postoperative analgesic consumption in BK group. No psychomimetic side effects or sedation were noticed in both groups.ConclusionsWe conclude that intraperitoneal instillation of low dose ketamine to bupivacaine 0.25% in elective LC significantly reduced post-operative shoulder pain and analgesic requirement when compared to bupivacaine 0.25% alone.