Subarachnoid Injection Research Articles

Targeted Epidural Blood Patch Under O-Arm-Guided Stereotactic Navigation in Patients with Intracranial Hypotension Associated with a Spinal Cerebrospinal Fluid Leak and Ventral Dural Defect.

Targeted epidural blood patch (EBP) at the site of a presumed cerebrospinal fluid leak reportedly has better outcomes than non-targeted EBP; however, it is associated with a higher risk of wrong-site injection, such as iatrogenic subarachnoid or intramuscular injections, which lead to reintervention because of the insufficient coverage of injected blood. Eight patients with intracranial hypotension owing to a CSF leak diagnosed with myelographic computed tomography (CT) and thin-cut magnetic resonance imaging (MRI) received an epidural blood patch under O-arm-guided stereotactic navigation. The leak site was identified on the basis of myelographic CT findings of a micro-spur, epidural contrast medium extravasations, and MRI findings of a ventral dural defect. During the EBP procedure, no iatrogenic dural puncture or subarachnoid injection occurred because O-arm-guided stereotactic navigation provided real-time feedback on the needle trajectory. O-arm CT revealed the sufficient coverage of injected blood following the first injection in 6 of 8 patients. In the 2 remaining patients, a second injection was performed during the same session because of insufficient coverage at the previous site. In all patients, complete recovery from orthostatic headaches was achieved after a single session. O-arm-guided navigation facilitated EBP by enabling real-time observations of the needle trajectory and distribution of injected blood while simultaneously avoiding major complications, such as wrong-site injections or reintervention.

Comparison of efficacy of intravenous dexmedetomidine with intravenous ketamine in allaying procedural discomfort during establishment of subarachnoid block

Background: Procedural discomfort is experienced by patients during the establishment of subarachnoid block even after good preoperative counseling and adequate premedication. The fear of needle prick, back pain during and after subarachnoid injection are becoming the leading causes for patient refusal to spinal anaesthesia. To enhance comfort and to overcome the denial, procedural sedation that would provide good analgesia, faster recovery and amnesia is inevitable. Materials and methods : Patients with ASA status I and II posted for elective surgeries under subarachnoid block were premedicated with midazolam 0.05mg/kg and pre-loaded with 10 ml/kg ringer lactate solution. They were randomized into 2 groups of 30 each. Group D received dexmedetomidine 1mcg/kg bolus over 10 min, group K received ketamine 0.3mg/kg intravenously. University of Michigan sedation score, ease of positioning, prick response, verbal response, hallucinations, recall of procedure and patient satisfaction were evaluated. Results : Both the drugs produced adequate sedation for performing subarachnoid block, UMSS score response to needle prick was comparable between them. Significant difference was observed during positioning the patient for subarachnoid block. Patients sedated with dexmedetomidine were able to position themselves without any help whereas patients sedated with ketamine required one or two persons help. In maintaining verbal response during the procedure both the drugs showed significant difference between them. In group D, most of the patients maintained the verbal response from immediately after bolus to throughout the study. Whereas in group K, no patient responded to verbal command after bolus up till 3min and majority of them (40%) regained verbal response only at 4min after bolus injection. There were no hallucinations and no recall of events in both groups. Except one patient in group D, all the patients were satisfied and willing to undergo subarachnoid block if need arises. Conclusion: We conclude that both ketamine and dexmedetomidine provided adequate sedoanalgesia for performing subarachnoid block. Dexmedetomidine was advantageous in terms of maintaining verbal response and ability to positioning themselves.

The mechanism of RvD1 alleviates type 2 diabetic neuropathic pain by influencing microglia polarization in rats

To study the relationship between microglia polarization in the spinal dorsal horn and type 2 diabetic neuropathic pain (DNP). And explore the mechanism of RvD1 alleviating type 2 diabetic neuropathic pain. Type 2 diabetes mellitus (T2DM) rats came from the male SD rats which were fed by high-fat and high-sucrose diet and given intraperitoneal streptozotocin(STZ), then detected fa sting blood glucose level, the mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL), which was to prepare the type 2 DNP model rats. And they were randomly divided into 3 groups:type 2 DNP group (group D), type 2 DNP and RvD1 group (group R), type 2 DNP and solvent control group (group S), 36 rats in each group. After being given STZ 14 days, the rats of group D, R, S were placed a catheter in subarachnoid cavity. Three days later, the RvD1 10μl (10 ng/μl) and 100% ethanol 10μl were injected into subarach-noid cavity through the catheter once a day for 14 consecutive days. Another 36 normal rats were served as normal control group (group N) and were fed with common forage. MWT and TWL were measured at 1, 3, 7, 14 days after Subarachnoid injection, then the nine rats'spinal cord of the lumbar segment 4~6 were removed to detect the expression of inducible nitric oxide synthase(iNOS) and arginase 1(Arg1) by Western blot, the marker of microglia M1 and M2 polarization. Compared with group N, MWT was decreased significantly and TWL was shortened, the expression of Arg1 was down-regulated and the expression of iNOS was up-regulated in spinal dorsal horn at the 1, 3, 7, 14 days in groups D and S (P < 0.05). Compared with group D, MWT was significantly increased and TWL was prolonged, the expression of Arg1 was up-regulated and the expression of iNOS was down-regulated in spinal dorsal horn at the 7, 14 days in group R (P < 0.05). There was no significant difference in the MWT, TWL and expression of Arg1 and iNOS between D and S groups. RvD1 promotes mi-croglia toward M2 polarization and alleviates type 2 diabetic neuropathic pain in rats.

Maintenance of the parturient in the left lateral position after spinal anesthesia with plain levobupivacaine for cesarean section reduces hypotension: a randomized study

Hypotension during spinal anesthesia is a main concern in cesarean delivery. The authors hypothesized that keeping parturients in a prolonged left lateral position before turning them to a supine position with left lateral tilt would reduce the incidence of hypotension without jeopardizing the quality of anesthesia. Randomized comparative unblinded prospective study. This randomized comparative prospective study was conducted at Gaziantep University Hospital between June and December 2011. Sixty parturients undergoing cesarean section were included. Patients were randomized to two groups: turning to the supine position with left lateral tilt immediately or 15 minutes after subarachnoid injection of 2.5 ml 0.5% plain levobupivacaine in the left lateral position. Loss of pinprick sensation to T6 was accepted as adequate for cesarean section, and surgery proceeded. Characteristics of anesthesia; incidences of hypotension, bradycardia, and other adverse events, and ephedrine use were assessed. Compared with the supine group, parturients kept in a lateral position for 15 minutes showed marked reductions in the incidence of hypotension (33.3% vs. 83.3%, p < 0.001) and adverse events related to hypotension, such as nausea and vomiting (16.7% vs. 57.3%, p <0.001). In addition, ephedrine consumption per hypotension case was significantly reduced in the lateral group (5.4 ± 4.7 vs. 8.9 ± 5.8 mg; p < 0.00 1). Keeping parturients in the lateral position for 15 minutes before turning them to the supine position for cesarean section can provide reliable spinal anesthesia with a lower incidence and severity of hypotension and nausea/vomiting.

Resistance of interleukin-6 to the extracellular inhibitory environment promotes axonal regeneration and functional recovery following spinal cord injury.

Interleukin-6(IL)-6 was originally discovered as a factor that contributes to the secondarypathological and inflammatory response in the central nervous system(CNS) following injury. However, accumulating evidence suggests that IL-6 is also involved in functional and structural recovery following CNS injury by promoting axonal sprou-ting. This suggests a potential dual role of IL-6 in CNS injury. However, the definitive function of IL-6 in neural injury and the corresponding underlying mechanisms are still topics of controversy. The present study was carried out to examine the potential function of IL-6 in resistance to neurite growth‑inhibitory effects via regulation of the expression of growth associated protein-43(GAP-43), myelin-associated neurite outgrowth inhibitor(Nogo-A) and its receptor(NgR). Rat dorsal root ganglion(DRG) neurons cultured in an inhibitory microenvironment mimicking injured CNS were used to investigate the effects of IL-6 on the outgrowth of neuronal processes. Additionally, IL-6 was subarachnoidally injected into rats to establish a spinal cord injury(SCI) model, and the neurobehavioral manifestations and neural morphology were subsequently evaluated to determine the effect of IL-6 on neural regeneration. Finally, the potential molecular mechanisms of IL-6-mediated rege-neration and functional recovery following CNS injury are discussed. The results of the present study demonstrated that the invitro administration of IL-6 enhanced the neurite outgrowth of DRG neurons in a dose-dependent manner via resisting the inhibitory function of myelin proteins. All doses of the IL-6 subarachnoid injection improved the Basso, Beattie and Bresnahan scores following SCI, with a large number of axonal sproutings observed at the spinal lesion site, and several sprouting fibers being elongated and bypassing the lesion and entered the caudal spinal cord. Additionally, a significantly increased density area of diaminobenzidine-labeled neural fiber was observed in rats that received a subarachnoid injection of IL-6, and the rats exhibited increased expression of GAP-43 and decreased expression of Nogo-A. Inconclusion, the results of the present study indicated that IL-6 interferes with the inhibitory functions of myelin proteins by upregulating the expression of GAP-43 and simultaneously downregulating the expression of Nogo-A andNgR to promote axonal sprouting and functional recovery following SCI.

Postmortem Redistribution of Lidocaine after Epidural Anesthesia Accidental Death

Epidural anesthesia is often used form in Chinese primary hospitals and lidocaine is the most favorite anesthetic. Fatalities due to epidural anesthesia accident and lidocaine overdose are often happened, but there still have not obvious evidence to indicate the real reason of death according to the concentration of lidocaine in postmortem blood because the postmortem redistribution (PMR). An animal models using dogs has been developed, whereby the dogs received an intravenous, subarachnoid, and epidural injection of lidocaine (75 mg/kg body weight). The dogs were placed at room temperature after sacrifice. The cardiac blood, inferior vena cava blood, liver and cerebrum samples were collected at 0 h, 1 h, 4 h, 8 h, 24 h, 48 h and 72 h postmortem with the same animal’s corpse. The lidocaine is easier diffusion from canalisvertebralis to cardiac blood in subarachnoid administration. The level commonly has a great change from 48 h after death in cardiac blood, from 35.7 mg/L to 1421.9 mg/L, and then decreasing 50% at 72 h. The inferior vena cava blood concentration was stabilized in postmortem time. The cerebrum concentration of subarachnoid administration decreased by 50% and was observed at 72 h after death. The changes were observed in cardiac blood in intravenous and epidural administration groups, but no changes were observed in cerebrum. Lidocaine concentrations did not change significantly in the liver in any of the three groups. This study can assist toxicologists to determine which specimens should be the most appropriately during the interpretation of lidocaine concentrations in epidural accidents.

Ultrasound as a safe and reliable guidance for subarachnoid puncture in rabbits.

To evaluate a model for studying the toxicity in nervous tissue and meninges using ultrasound to guide needle insertion into the subarachnoid space of rabbits, with the objective of avoiding injuries triggered by the puncture and by intraneural injection of solutions. Forty-five adult female rabbits were divided into 3 groups (G): G1 underwent subarachnoid puncture, G2 underwent subarachnoid injection of saline solution and G3 underwent subarachnoid injection of 0.5% hyperbaric bupivacaine. A needle was inserted into the S1-S2 subarachnoid space guided by ultrasound. The sensitivity and motility of the animals were evaluated for 3 days, after which the animals were sacrificed for removal of lumbar and sacral portions of the spinal cord for histological examination by light microscopy and immunohistochemistry. All animals had motor function and pain sensitivity on the evaluation period. No animal had complication during or after the procedures. Ultrasound is a useful and safe method for the correct identification of the subarachnoid space of rabbits.

Combined spinal-epidural anesthesia with hypobaric ropivacaine in sitting position significantly increases the incidence of hypotension in parturients undergoing cesarean section.

Maternal position during induction of combined spinal-epidural anesthesia (CSEA) may affect hemodynamics and block characteristics. This study aimed to assess whether the sitting position is more likely to induce hypotension and higher block level than the lateral position in CSEA with hypobaric ropivacaine. Ninety American Society of Anesthesiologists physical status I and II parturients undergoing elective cesarean section were randomized into three groups: the sitting, left-lateral, and right-lateral position groups. The L3-4 interspace was selected as the puncture site, and subarachnoid injection of 2.5 mL 0.5% hypobaric ropivacaine was administered. After the epidural catheter was inserted and fixed, the patient's position was changed to the left-leaning supine position. The blood pressure was measured once every 1 min followed by once every 3 min after the delivery. The sensory block level was regularly measured. A total of 88 parturients were included in this study. The incidences of hypotension in the sitting, left-lateral, and right-lateral position groups were 72%, 38%, and 40%, respectively, P = 0.012. Incidence and total dose of the phenylephrine supplement in the sitting position group were significantly higher than in the other two groups. The sitting position group showed a significantly higher block level (T4 [T3, T4]) as compared to the left-lateral (T6 [T5, T6]) and right-lateral position groups (T6 [T4, T6]), P < 0.01. The Apgar scores of neonates at 1 min and 5 min, and the pH values of the umbilical arterial and venous blood were similar among the three groups. As compared to the lateral positions, CSEA with hypobaric ropivacaine in the sitting position is more likely to cause hypotension and excessively high block level.

Paraplegia Following Epidural Steroid Injection

Paraplegia following epidural steroid injection is, fortunately, an exceedingly rare complication. The differential diagnosis includes epidural hematoma, spinal cord injury/infarction, epidural abscess, and conversion disorder. Less likely diagnoses include worsening of underlying pathology, a new compressing lesion, or subarachnoid injection. The artery of Adamkiewicz enters the spinal canal via the neural foramen and provides blood supply to the lower two thirds of the spinal cord via the anterior spinal artery. Avoidance of the artery during a transforaminal epidural steroid injection is facilitated by entering the inferior portion of the foramen. Acute management of neurologic complications arising from an epidural steroid injection is facilitated by rapid identification of etiology. In the case of epidural hematoma, avoidance of permanent deficit is more likely when patients undergo prompt decompression. The role of intravenous steroids in acute spinal cord injury is controversial. Chronic management includes extensive rehabilitation, including physical and occupational therapy. Treatment of musculoskeletal nociceptive pain, such as due to shoulder overuse, and neuropathic pain is vital to optimize the patient’s participation in rehabilitative therapy. Keywords: Epidural Steroid Injection; Complications; Spinal Cord Injury; Epidural Hematoma; Epidural Abscess; Artery of Adamkiewicz; Anterior Spinal Artery Syndrome; Particulate Steroid; Fluoroscopic Guidance

Effect of dexmedetomidine-assisted continuous femoral nerve block analgesia after total knee arthroplasty (TKA)

Objective To investigate the effects of dexmedetomidine on ropivacaine for continuous femoral nerve block (CFNB) analgesia after total knee arthroplasty (TKA). Methods Forty patients after TKA were randomly assigned into two groups of T and C (n=20 cases each group). All of the patients received spinal-epidural combined anesthesia, subarachnoid injection of 0.5% isobaric ropivacaine 3 ml, intraoperative epidural space according to the need of surgery an extra 0.375% ropivacaine paid for 3 to 5 ml. Postoperative analgesia with continuous femoral nerve block was performed in both groups, after the puncture of femoral nerve, group T was injected with 0.375% ropivacaine + dexmedetomidine mixed solution 20 ml (with dexmedetomidine 0.6 μg/kg), group C were injected with 0.375% ropivacaine 20 ml. Placement of continuous femoral nerve catheter, two groups of patients were performed operation continuous femoral nerve block analgesia and CFNB with 0.75% ropivacaine 50 ml, added saline diluted to 200 ml (each bag). Background infusion was 4 ml per hour; the demand dose was 4 ml in a lockout interval of 30 minutes. Two groups of patients were recorded rest visual analogue scale (RVAS) and passive visual analogue scale (PVAS) postoperative 6, 24, 48 and 72 h. Serum concentration of tumor necrosis factor-α (TNF-α), interleukin(IL)-1β and IL-6 were measured with double sandwich enzyme-linked immunosorbent assay (ELISA) method before anesthesia and postoperative in 24, 48, and 72 hours. Analgesia-related adverse reactions such as delirium, nausea and vomiting, urinary retention were record. Results Compared to group C, postoperative RVAS and PVAS of 6, 24 and 48 h wrere significantly decreased (P<0.05). Postoperative serum concentrations of TNF-α, IL-1β and IL-6 in 24, and 48 hours in group T were lower than those in group C (P<0.05). Group T incidence of postoperative sinus bradycardia was lower than the group C (P<0.05). Conclusions Dexmedetomidine combined with ropivacaine analgesia may effectively improve the TKA postoperative analgesic effect of CFNB, to reduce the levels of serum inflammatory factors, and depress stress reaction after operation. Key words: Dexmedetomidine/AD; Procaine/AD; Femoral nerve; Nerve block; Arthroplasty, replacement, knee; Analgesia

Longitudinal measurements of syrinx size in a rat model of posttraumatic syringomyelia.

OBJECTIVE Syringomyelia pathophysiology is commonly studied using rodent models. However, in vivo studies of posttraumatic syringomyelia have been limited by the size of animals and lack of reliable noninvasive evaluation techniques. Imaging the rat spinal cord is particularly challenging because the spinal cord diameter is approximately 1-3 mm, and pathological lesions within the spinal cord parenchyma are even smaller. The standard technique has been histological evaluation, but this has its limitations. The aim of the present study was to determine whether syrinx size could be reliably measured using a preclinical high-field MRI animal system in a rat model of posttraumatic syringomyelia. METHODS The authors used an existing rat model of posttraumatic syringomyelia, which was created using a controlled pneumatic compression device to produce the initial spinal cord injury, followed by a subarachnoid injection of kaolin to produce arachnoiditis. T2-weighted MRI was performed on each animal using a 9.4-T scanner at 7, 10, and 13 weeks after injury. Animals were killed and syrinx sizes were calculated from in vivo MRI and histological studies. RESULTS MRI measurements of syrinx volume and length were closely correlated to histological measurements across all time points (Pearson product moment correlation coefficient r = ± 0.93 and 0.79, respectively). CONCLUSIONS This study demonstrates that high-field T2-weighted MRI can be used to measure syrinx size, and data correlate well with syrinx size measured using histological methods. Preclinical MRI may be a valuable noninvasive technique for tracking syrinx formation and enlargement in animal models of syringomyelia.

The Incidence of Intradiscal, Intrathecal, and Intravascular Flow During the Performance of Retrodiscal (Infraneural) Approach for Lumbar Transforaminal Epidural Steroid Injections.

Lumbar transforaminal epidural steroid injections (TFESIs) are often used in the treatment of radicular pain. In light of safety concerns, many practitioners have proposed adopting the retrodiscal (infraneural) approach with the needle tip positioned into Kambin's triangle. With this technique, the needle may inadvertently be directed too far ventrally and enter the intervertebral disc. In addition, the risk of subarachnoid or subdural extra-arachnoid injection may be higher with this technique as well. To determine the incidence of inadvertent intradiscal, intrathecal, and vascular injections during the performance of retrodiscal TFESI. Retrospective review Retrospective review of all retrodiscal approach TFESIs performed from July 2012 to August 2014 by two of the authors (DL and SH). A total of 257 retrodiscal transforaminal injections were performed. There were no neurologic complications. There were no cases of discitis. Inadvertent intradiscal injections occurred in 12/257 injections, 4.7% (95% CI 2.1-7.3%). Intrathecal injections occurred in 8/257 injections, 3.1% (95% CI 0.99- 5.23%). Three were subarachnoid (SA), four were subdural extra-arachnoid (SDXA), and one was both SA and SDXA. Vascular injections occurred in 17/257, 6.6% (95% CI 3.6-9.6%). This retrospective review demonstrates that a relatively high rate of inadvertent intradiscal injections occurs in the performance of the retrodiscal approach for TFESI. This has significant implications in terms of the potential risk of disc injury induced by the needle puncture. The high incidence of intrathecal injections may also be of great concern depending upon the injectate delivered.

Subarachnoid injection of ifenprodil and ketamine association improves the anti-hyperalgesic action of ketamine in dogs

To test clinically whether a small dose of ifenprodil can enhance the anti-hyperalgesic effect of ketamine in dogs, a prospective randomized cross-over study was done with eight mongrel dogs (weighing 16.9 ± 3.7kg). Animals received two distinct treatments: ketamine (0.3mg kg-1; KT) and an ifenprodil plus ketamine combination (0.03mg kg-1 and 0.3mg kg-1, respectively; IKT). Dogs were anesthetized with propofol (5mg kg-1 intravenously) and a subarachnoid needle was placed between the 5th and 6th lumbar vertebrae. Five minutes after subarachnoid injection of KT or IKT, an incision including cutaneous and subcutaneous tissues was made on the common pad of one hind limb and was immediately closed with a simple interrupted suture pattern. The dogs were treated again 20 days later, using the contralateral pad and the opposite treatment. Sedation score (SS), lameness score (LS), heart rate (HR), respiratory rate (fR), and mechanical nociceptive threshold using von Frey filaments, were evaluated before anesthesia and at 1, 1.5, 2, 3, 4, 8, 12, and 24 hours after subarachnoid injection. There were no differences in SS, LS, HR or fR between treatments. The intensity of hyperalgesia was higher in KT than in IKT for 24 hours. The anti-hyperalgesic effect of IKT remained without statistical significant difference between 1 and 24 h. Prior subarachnoid administration of ifenprodil enhances the anti-hyperalgesic effect of subarachnoid ketamine in dogs. Ifenprodil can be co-administrated with ketamine to enhance its anti-hyperalgesic effect and to reduce acute post-incisional hyperalgesia without motor impairment and sedation.

A fatal accidental subarachnoid injection of lidocaine and levobupivacaine during a lumbar paravertebral block

Paravertebral block (PVB) is the technique of injecting a local anesthetic solution alongside the vertebral column, close to where the spinal nerves emerge, resulting in unilateral somatic and sympathetic nerve blockade. Here is reported a fatal case involving a 60-year-old woman with spondylitis arthropathy, who developed cardiac and respiratory arrest 40min after receiving an accidental subarachnoid injection (L5-S1 bilaterally) of depomedrol lidocaine and levobupivacaine. A complete autopsy including histological and toxicological analyses was performed in order to establish the cause of death. Liquid/liquid extraction (LLE) and GC–MS analysis were performed according to a previously published method. Lidocaine and bupivacaine were detected both in blood, at concentrations of 14.8mg/L and 13.3mg/L respectively, and in cerebrospinal fluid (CSF) at concentrations of 287.1mg/L and 464.2mg/L respectively. Both lidocaine and bupivacaine were also detected in the urine. The toxicological findings along with the autopsy allowed us to establish that the accidental subarachnoid injection of lidocaine and levobupivacaine had led to a progressive hypotension and normovolaemic shock caused by a severe ganglionic block, determining the patient's death.

Effect of umbilical cord mesenchymal stromal cells on motor functions of identical twins with cerebral palsy: pilot study on the correlation of efficacy and hereditary factors

Background aimsThe objective of this study was to compare the impact of umbilical cord–derived mesenchymal stromal cell (UCMSC) transplantation on the motor functions of identical twins with cerebral palsy (CP) and to analyze the correlation between the efficacy and hereditary factors. MethodsEight pairs (16 individuals) of identical twins with CP were recruited and received allogenic UCMSC transplantation by means of subarachnoid injection. The gross motor function measure (GMFM) and the fine motor function measure (FMFM) were performed before and 1 and 6 months after the treatment to analyze the results of individuals before and after the therapy, between two individuals of an identical twin and among twin pairs. Repeated-measured data variance was used to analyze the GMFM and FMFM scores of patients before and 1 and 6 months after the therapy. ResultsEight pairs (16 individuals) of children with CP had significant improvement in the GMFM at the end of the 1st and 6th months after the therapy compared with that before the therapy, whereas the amelioration of the FMFM was not statistically significant. The improvements in motor functions between two individuals of an identical twin but not among twin pairs were correlated. ConclusionsUCMSC transplantation significantly improves GMFM in children with CP; motor function improvements in the GMFM between two individuals of an identical twin were closely correlated, but improvements among twin pairs were not correlated. We hypothesize that hereditary factors contribute to the mechanisms of UCMSC transplantation in motor function improvement in children with CP.

Continuous spinal analgesia with levobupivacaine for postoperative pain management: Comparison of 0.125% versus 0.0625% in elective total knee and hip replacement: A double-blind randomized study.

Background and Aims:Continuous spinal anesthesia (CSA) has not been widely used for postoperative analgesia, mainly to avoid complications from the subarachnoid injection. Recently, the introduction of low caliber CSA catheters (Spinocath®), has allowed to decrease anesthetics doses and volumes with good analgesia and reduced complications. The aim of this present study was to compare two concentrations of levobupivacaine administered through CSA for postoperative pain management after major orthopedic surgery. Secondary outcomes were adverse events associated with CSA.Material and Methods:Thirty-two patients were randomized to receive sufentanil 1 mcg/h plus levobupivacaine 0.125%-1 ml/h (Group A0.125) or 0.0625%-2 ml/h (Group B0.0625) for postoperative analgesia through CSA catheter, connected to the elastomeric pump over 48 h. The quality of analgesia was assessed based on pain intensity by Visual Analogic Scale (VAS). Sensory and motor function, hemodynamic, and respiratory parameters were recorded for 96 h after surgery, after which the catheter was removed. In addition, joint mobility was assessed, and any side effects were noted.Results:VAS score was ≤30 mm in 25 patients. Three patients in Group A0.125 and 4 in Group B0.0625 (NS), received a rescue dose of levobupivacaine. Median VAS in Group A0.125 was lower than in Group B0.0625 on T1h (8 ± 11 vs 16 ± 11; P < 0.05), and on T4h (11 ± 8 vs 18 ± 1; P < 0.05). All patients remained hemodynamically stable. There were no significant differences between groups for postoperative joints mobility.Conclusion:Levobupivacaine at a dose of 1.25 mg/h administered by CSA provides good quality analgesia independent of concentration and solution volume in patients undergoing total knee and hip replacement.

Comparison of the Concentrations of Lidocaine in Different Body Fluids/Tissues after Subarachnoid Space and Intravenous Administration of a Lethal Dose of Lidocaine

The objective of the study was to compare the concentration of lidocaine in different body fluids/tissues after subarachnoid space and intravenous administrations of a lethal dose of lidocaine. Totally 18 dogs were used in the experiment. Six dogs were given subarachnoid anesthesia, another were given an intravenous injection of a dose of 75 mg/kg weight of lidocaine hydrochloride in 5 min and the last 6 dogs were used as the blank control dogs and given a subarachnoid space injection or a femoral artery injection of the same volume of sodium chloride. As soon as its vital signs disappeared, each dog was dissected and the specimen, such as brain, cerebrospinal fluid (CSF) in lateral ventricle, CSF in subarachnoid space, spinal cord (cervical spinal cord, thoracic spinal cord, lumbar spinal cord, and waist spinal cord), heart, lung, liver, spleen, kidney, bile, urine, heart blood, peripheral blood, muscle in injection location, and muscle in no injection location, were collected for analysis of lidocaine immediately. Analysis was performed with gas chromatography-mass spectrometry (GC-MS). From the maximum to the minimum, the order of lidocaine concentration detected in the subarachnoid space-administered dogs was as follows: CSF in subarachnoid space, waist spinal cord, thoracic spinal cord, CSF in lateral ventricle, lumbar spinal cord, cervical spinal cord, lung, kidney, muscle in injection location, heart, brain, spleen, heart blood, liver, peripheral blood, bile, muscle in no injection location, and urine. The order of lidocaine concentration detected in the intravenously administered dogs was as followed: Kidney, heart, lung, spleen, brain, liver, peripheral blood, bile, heart blood, cervical spinal cord, thoracic spinal cord, muscle in injection location, lumbar spinal cord, muscle in no injection location, CSF in subarachnoid space, urine, and CSF in lateral ventricle. The maximum concentration of lidocaine was detected in the subarachnoid space CSF of subarachnoid space-administered dead dogs, while in intravenously injected dead dogs, the maximum concentration of lidocaine was detected in the kidney. Our study provides some useful data for the forensic identification of epidural anesthesia accidents to decide the way the lidocaine enters the body.

Adjuvant granulocyte colony-stimulating factor therapy results in improved spatial learning and stimulates hippocampal neurogenesis in a mouse model of pneumococcal meningitis.

Despite the development of new antibiotic agents, mortality of pneumococcal meningitis remains high. In addition, meningitis results in severe long-term morbidity, most prominently cognitive deficits. Granulocyte colony-stimulating factor (G-CSF) stimulates proliferation and differentiation of hematopoietic progenitor cells and increases the number of circulating neutrophil granulocytes. This study investigated the effect of adjuvant G-CSF treatment on cognitive function after pneumococcal meningitis. C57BL/6 mice were infected by subarachnoid injection of Streptococcus pneumoniae serotype 3 and treated with ceftriaxone and G-CSF subcutaneously or ceftriaxone alone for 5 days. Clinical scores, motor performance, and mortality during bacterial meningitis were unaffected by adjuvant G-CSF treatment. No effect of G-CSF treatment on production of proinflammatory cytokines or activation of microglia or astrocytes was observed. The G-CSF treatment did, however, result in hippocampal neurogenesis and improved spatial learning performance 6 weeks after meningitis. These results suggest that G-CSF might offer a new adjuvant therapeutic approach in bacterial meningitis to reduce long-term cognitive deficits.

Asymptomatic ventricular dilatation precedes clinical decline in rodent adult chronic communicating hydrocephalus

IntroductionThe pathogenesis and behavioral effects of normal pres-sure hydrocephalus (NPH) are not fully understood, andthe temporal relationship between radiological changesand neurological deterioration is unknown.MethodsBilateral subarachnoid injections of kaolin were adminis-tered in the cranial convexities of 20 adult rats. MRI wasobtained using a Bruker Biospec 11.7 T MRI scanner at14, 60, 90 and 120 days post kaolin injection. Locomotor,gait, and cognitive studies were performed independentlyevery 2 weeks by faculty blinded to the imaging results.Tests included open field test, gait analysis, rotarod andnovel object recognition. Logistic regression analysis wasperformed to assess association between ventricular sizeand clinical deterioration and rate of ventricular sizeenlargement and clinical deterioration.ResultsRadiological ventricular size showed progressive growthover time at all times (p 0.05), cognitive (p>0.05) or anxiety(p>0.05) deterioration. Locomotor deterioration wasassociated with ventricular size (p=0.014), speed of ven-tricular enlargement (p=0.015) and extension of injectedkaolin (p=0.04).ConclusionsKaolin injected in the subarachnoid space of adult ratscan produce slow onset communicating hydrocephalus.Initially the ventricular enlargement seen on images isasymptomatic. Ventricular enlargement does not corre-late with clinical impairment with exception of delayedlocomotor impairment.

Single shot spinal anaesthesia with hypobaric bupivacaine for hip fracture repair surgery in the elderly. Randomized, double blinded comparison of 3.75 mg vs. 7.5 mg

BackgroundArterial hypotension is the most frequent adverse effect of subarachnoid anaesthesia in the elderly sustaining a femoral proximal fracture. Decreasing the local anaesthetic dose reduces the incidence of hypotension but shortens sensory block duration that could be insufficient in some surgical procedures. Sensory block duration could be prolonged using hypobaric local anaesthetics. We evaluated whether low hypobaric bupivacaine doses were adequate for this type of surgery while maintaining the haemodynamic stability. MethodsA prospective, randomized, double blinded study was designed. Patients over 65 years old, sustaining traumatic hip fracture, were assigned to one of two groups: B0.5 group, hypobaric bupivacaine 7.5mg 5mg/ml (control group), and B0.25 group, hypobaric bupivacaine 3.75mg 2.5mg/ml (study group). After subarachnoid injection, sensory level and motor blockade degree were registered, as were blood pressure, and heart rate at basal time and at 2, 5, 10, 15, 20 and 30min after injection. The doses of vasopressor needed were registered as well. Surgical conditions and the duration of the surgical procedure—whether rescue analgesia or anaesthesia was needed—and sensory level regression to T12, were registered as well. ResultsSixty four patients was the calculated sample size. The study was stopped in an interim analysis because an elevated number of patients in the B0.25 group needed iv rescue anaesthesia. In the analyzed cases, blood pressure was significantly lower in the B0.5 group at the 15 and 30min measurements. Vasopressor drugs needs were similar between groups [ephedrine accumulated mean (SD) doses 11.4 (5.2) mg vs. 9.1 (2.7) mg, p=0.045)]. Sensory block regression to T12 was faster in the B0.25 group, [(mean (SD) 68.2 (29.0) min vs. 112.8 (17.3) min in the B0.5 group, p<0.05]. Five out of 19 patients in the B0.25 group needed intravenous anaesthesia rescue before surgery started. ConclusionLowering hypobaric bupivacaine dose to 3.75mg in subarachnoid anaesthesia for hip fracture repair surgery in elderly patients decrease intraoperative blood pressure, but in an important number of patients intravenous anaesthesia rescue was needed and preclude recommendation.