Epidurals

The epidural space surrounds the dura mater of the spinal cord. It is bounded by the pedicles of the vertebral arches and by the anterior and posterior ligaments connecting the bony vertebral column. The epidural space contains nerve roots, fat, and blood vessels. 

Epidermal Growth Factor (EGF) Receptor Family Epidermal Growth Factor Receptor 2 (ErbB2) Epidural (Space)... 

Intrathecally or epidurally for pain relief for extended periods without apparent loss of motor, sensory, or sympathetic function... 

Access to the epidural route is made through the use of a percutaneous epidural catheter. The placement of the catheter requires strict aseptic technique by a skilled physician. The epidural catheter is placed into the space... 

Spinal cord I Epidural space Arachnoid space... 

This type of pain management is used for postoperative pain, labor pain, and cancer pain. The most serious adverse reaction associated with the administration of narcotics by the epidural route is respiratory depression. The patient may also experience sedation, confusion, nausea, pruritus, or urinary retention. Fentanyl is increasingly used as an alternative to morphine sulfate because patients experience fewer adverse reactions. 

Sufentanil, fentanyl, remifentanil, alfentanil, and morphine sulfate should be administered only by those specifically trained in the use of IV and epidural anesthetics Oxygen, resusdtative, and intubation equipment should be readily available. 

Nursing care includes close monitoring of the patient immediately after insertion of the epidural catheter and throughout therapy for respiratory depression. Vital signs are taken every 30 minutes, apnea monitors are used, and a narcotic antagonist, such as naloxone, is readily available... 

A conduction block is a type of regional anesthesia produced by injection of a local anesthetic drug into or near a nerve trunk. Examples of a conduction block include an epidural block (injection of a local anesthetic into the space surrounding the dura of the spinal cord) a trails sacral (caudal) block (injection of a local anesthetic into the epidural space at the level of the sacrococcygeal notch) and brachial plexus block (injection of a local anesdietic into the brachial plexus). Epidural, especially, and trailssacral blocks are often used in obstetrics. A brachial plexus block may be used for surgery of the arm or hand. 

Volk T, Schenk M, Voigt K, Tohtz S, Putzier M, Kox WJ (2004) Postoperative epidural anesthesia preserves lymphocyte, but not monocyte, immune function after major spine surgery. Anesth Analg 98(4) 1086-1092... 

Other methods for ICP monitoring include Camino ICP monitors, which are positioned into the brain parenchyma, but do not transverse the hemisphere nearly to the degree that EVDs do, and are associated with a lower risk of intracerebral hemorrhage. The ICP is measured by a fiberoptic transducer at the tip of the cathe-ter. ° ICP monitors, however, are subject to inaccuracy over time, so-called drift, and thus may become less reliable after the first few days post-insertion. Epidural and subarachnoid bolts/catheters are the least invasive, placed external to or just within the dura, thereby carrying a much lower risk of hemorrhage and infection, but with unfortunately compromised accuracy. 

Opioids maybe administered in a variety of routes including oral (tablet and liquid), sublingual, rectal, transdermal, transmucosal, intravenous, subcutaneous, and intraspinal. While the oral and transdermal routes are most common, the method of administration is based on patient needs (severity of pain) and characteristics (swallowing difficulty and preference). Oral opioids have an onset of effect of 45 minutes, so intravenous or subcutaneous administration maybe preferred if more rapid relief is desired. Intramuscular injections are not recommended because of pain at the injection site and wide fluctuations in drug absorption and peak plasma concentrations achieved. More invasive routes of administration such as PCA and intraspinal (epidural and intrathecal) are primarily used postoperatively, but may also be used in refractory chronic pain situations. PCA delivers a self-administered dose via an infusion pump with a preprogrammed dose, minimum dosing interval, and maximum hourly dose. Morphine, fentanyl, and hydromorphone are commonly administered via PCA pumps by the intravenous route, but less frequently by the subcutaneous or epidural route. 

Epidural analgesia is frequently used for lower extremity procedures and pain (e.g., knee surgery, labor pain, and some abdominal procedures). Intermittent bolus or continuous infusion of preservative-free opioids (morphine, hydromorphone, or fentanyl) and local anesthetics (bupivacaine) may be used for epidural analgesia. Opiates given by this route may cause pruritus that is relieved by naloxone. Adverse effects including respiratory depression, hypotension, and urinary retention may occur. When epidural routes are used in narcotic-dependent patients, systemic analgesics must also be used to prevent withdrawal since the opioid is not absorbed and remains in the epidural space. Doses of opioids used in epidural analgesia are 10 times less than intravenous doses, and intrathecal doses are 10 times less than epidural doses (i.e., 10 mg of IV morphine is equivalent to 1 mg epidural morphine and 0.1 mg of intrathecally administered morphine).45... 

Intraepidural (into epidural 6-30 5 in., 16-18 gauge Must be isotonic Local anesthetics, narcotics,... 

Discuss the mechanisms by which spinal anesthesia and epidural anesthesia exert their effects... 

Epidural anesthesia is administered by injecting local anesthetic into the epidural space. Located outside the spinal cord on its dorsal surface, the epidural space contains fat and is highly vascular. Therefore, this form of anesthesia can be performed safely at any level of the spinal cord. Furthermore, a catheter may be placed into the epidural space, allowing for continuous infusions or repeated bolus administrations of anesthetic. 

The primary site of action of epidurally administered agents is on the spinal nerve roots. As with spinal anesthesia, the choice of drug to be used is determined primarily by the duration of anesthesia desired. However, when a catheter has been placed, short-acting drugs can be administered repeatedly. Bupivacaine is typically used when a long duration of surgical block is needed. Lidocaine is used most often for intermediate length procedures chloroprocaine is used when only a very short duration of anesthesia is required. 

An important difference between epidural anesthesia and spinal anesthesia is that agents injected into the epidural space may readily enter the blood due to the presence of a rich venous plexus... 

Morphine may be administered orally, intravenously, or epidurally. An advantage of epidural administration is that it provides effective analgesia while minimizing the central depressant effects associated with systemic administration. The mechanism of action with the epidural route of administration involves opioid receptors on the cell bodies of first-order sensory neurons in the dorsal root ganglia as well as their axon terminals in the dorsal hom. Stimulation of these receptors inhibits release of substance P and interrupts transmission of the pain signal to the second-order sensory neuron. 

Intrathecal (IT) Into the subarachnoid space between two of the membranes (meninges) separating the spinal cord from the vertebral column. This route is used for drugs that do not penetrate the blood-brain barrier, but which are required for their central action (e.g., antibiotics). Drugs can also be injected spinally (into the epidural space) for local anaesthesia or analgesia. 

The IV or IM administration of parenteral narcotics (meperidine, morphine, fentanyl) is commonly used to treat the pain associated with labor. Compared to epidural analgesia, parenteral opioids are associated with lower rates of oxytocin augmentation, shorter stages of labor, and fewer instrumental deliveries. 

Morphine is often the choice in this category (1) multiple products available (2) multiple route of administration options, such as oral, rectal. IM. SC. IV. epidural, and intrathecal and (3) a known eqiipotency between these routes that allows a much easier transition. 

---