Intrathecal Space

The intrathecal space is located between the arachnoid and the pia mater of the spinal cord. It contains the cerebrospinal fluid, spinal nerves and blood vessels. 

Intracellular Transport Intrathecal Application Intrathecal Space Intrinsic Efficacy Intron... 

Regional analgesia with local anesthetics (Table 54-6) can provide relief of both acute and chronic pain. Anesthetics can be positioned by injection (i.e., in joints, in the epidural or intrathecal space, along nerve roots) or applied topically. 

Intrathecal Management of severe spasticity of spinal cord origin in patients who are unresponsive to oral baclofen therapy or experience intolerable CNS side effects at effective doses. Intended for use by the intrathecal route in single bolus test doses (via spinal catheter or lumbar puncture) and, for chronic use, only in implantable pumps approved by the FDA specifically for the administration of baclofen into the intrathecal space. 

Consistent with these hypotheses is the finding that continuous infusion of the opioid into the epidural or intrathecal space provides optimal pain relief postoper-atively or in chronic, intractable pain.2 40 83 Continuous infusion is associated with certain side effects, especially nausea and constipation, as well as the potential for disruption of the drug delivery system.24 57 77 Problems with tolerance have also been reported during continuous administration,27 but it is somewhat controversial whether tolerance really develops when these drugs are used appropriately in the clinical management of pain (see section on Concepts of Addiction, Tolerance, and Physical Dependence ). Hence, the benefit-to-risk ratio for continuous epidural or intrathecal infusion is often acceptable in patients with severe pain. This method of opioid administration continues to gain acceptance.24 57... 

In vivo capsule viability screen. The intrinsic behavior of the cells, diffusion of nutrients and cofactors, and immunogenicity all affect the viability and function of the cells in capsules. Multiple capsule configurations and cell matrix membrane combinations were tested. The combination of cell ECM scaffold was encapsulated with different membranes and capsules were implanted into CNS and ocular sites (such as rat ventricle, rabbit eye, dog eye, pig eye, and sheep intrathecal space). The optimal cell-matrix membrane combinations that show longevity and functional stability in vivo were chosen for further development. 

Baclofen is absorbed orally, reaching peak plasma concentration in 2 hours, having a half-life of 3 to 4 hours, and being excreted unchanged by the kidneys. The onset and duration of action of baclofen are 4 and 8 hours, respectively. It should be given cautiously in patients with renal impairment. The administration of baclofen via spinal catheter or lumbar puncture in a single bolus test dose of 50 to 100 meg, or via an implantable pump for administration into the intrathecal space, has been approved for severe spasticity and pain in patients with cerebral palsy not responding to oral medications. 

The client diagnosed with low back pain is scheduled to have a steroid injection into the intrathecal space. Which statement by the client indicates that the client understands the procedure ... 

Implantable drug delivery systems are defined as longterm (>30 days) implantable products that are resorbable or removable. The resorbable implants are injectables incorporating lyophilized microspheres. The removable version is typically a subcutaneous implant, requiring minor outpatient procedures for insertion and removal. The main commercialized product in this category is Norplant , a contraceptive implant. Medtronic Corporation has two products in the implantable area that allow drug delivery into the intrathecal space (where the spinal fluid circulates). One of these products delivers baclofen for spasticity, and the other delivers anaesthetics for pain control. Both products utilize Medtronic s SynchroMed infusion pump, which can be electronically programmed to deliver any type of preset dose. 

In retrospect, it was realized that the drugs given by the caudal route had been accidentally administered into the intrathecal space, namely an ectatic lumbosacral dural sac, which had been overlooked in the initial MRI scan. This case highlights the importance of looking for lumbosacral dural anomahes before planning caudal epidural injections in adults such anomalies should be regarded as contraindications for caudal epidural analgesia. 

Since intravenous solutions have been accidentally applied into intrathecal space, international guidelines have been issued to prevent this occurring. A major recommendation is to use a non-luer connector (see Sect. 13.10.2) in neuraxial procedures. The first non-luer connectors for intrathecal administration were launched in UK. However, standardisation of these connectors is required [5]. 

An epidural catheter that is working very well but causing hypotension, excessive pruritus, and muscle weakness could be in the intrathecal space. Alternatively, the catheter could be in the epidural space but the infusate could be leaking into the intrathecal space through a dural puncture made inadvertently during placement of the epidural. Decrease the infusate solution rate to 1-2 mL/h, and use a dilute naloxone solution of 400-800 pg/L of the IVF already prescribed by the primary team (at a rate of75-150 mL/h dependent on patient s fluid requirements). 

Two clinical trials were done to verify the safety of ropivacaine in the intrathecal space, both with doses of 3 mL. Both studies showed that 3 mL doses did pro- 277 duce an adequate spinal anesthesia blockade with no... 

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