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Background and Objectives: A test dose containing epinephrine is routinely used during epidural blockade to detect accidental intravenous needle or catheter placement before the administration of local anesthetics to avert local anesthetic systemic toxicity. β-Blocker therapy may interfere with the expected hemodynamic response from an intravascular injection. This study describes a cohort of 24 patients and their response to an epinephrine test dose (ie, if expected increased heart rates during test-dose administration are valid in this population.) Methods: Twenty-four nonsedated, chronically β-blocked patients were enrolled in a prospective, order-randomized, crossover, double-blind study with injections of both placebo and a 15-μg epinephrine test dose in each individual. After injection into a peripheral vein, we observed blood pressure and pulse rate for 5 minutes, injected the other remaining solution (placebo or epinephrine), and observed hemodynamic parameters in the same...

ST: Subcutaneous Tissue;  EO: External Oblique; IO: Internal Oblique; TA: Transversus Abdominus; LD: Latissimus Dorsi; QL:Quadratus Lumborum Authors Carney J,   et al.  Journal Anaesthesia. 2011 Nov;66(11):1023-30. doi: 10.1111/j.1365-2044.2011.06855.x. Epub 2011 Aug 18. Affiliation Department of Anaesthesia and Intensive Care Medicine, Galway University Hospitals, Galway, Ireland. Abstract The extent of analgesia provided by transversus abdominis plane blocks depends upon the site of injection and pattern of spread within the plane. There are currently a number of ultrasound-guided approaches in use, including an anterior oblique-subcostal approach, a mid-axillary approach and a more recently proposed posterior approach. We wished to determine whether the site of injection of local anaesthetic into the transversus abdominis plane affects the spread of the local anaesthetic within that plane, by studying the spread of a local anaesthetic and contras...

Identify the the w,X,Y,Z? Scroll down ...the answer there

The following is a brief description of the Raj test: when nerve stimulation is being used to locate a nerve, a twitch is observed when the needle tip is close to the neural target. Ideally, the twitch is required to persist at a current of 0.5 mA. The clinician then injects a small volume of local anesthetic or normal saline through the needle. I f the needle tip is in the correct location, the muscle twitch immediately disappears. Until very recently the disappearance of the twitch was thought to be caused by physical displacement of the nerve by the injectate. We recently learned that this mechanism is best explained in electrical terms and is not entirely a result of the physical dis- placement of the nerve. In a porcine model, the injection of 0.9% sodium chloride solution (NaCl) abolished the motor response, and a subsequent injection of 5% dextrose reestablished a motor response during peripheral nerve stimulation. An accompanying  in v...

There have been few studies comparing the midline and paramedian approach on block success.  In cadavers, using epiduroscopy, paramedian catheters were observed to cause less epidural tenting, and pass cephalad more reliably than midline catheters. In patients, faster catheter insertion times were reported in the paramedian, and higher incidence of paraesthesia in the midline group. Adequate local infiltration is a prerequisite for patient comfort during paramedian puncture. The paramedian approach may be less dependent upon spine flexion. The risk of vascular puncture during epidural catheter placement was not associated with lumbar midline or paramedian technique in parturients, while another study suggested more paraesthesia and bloody puncture in non-pregnant adults when the midline approach was used. 1-Blomberg RG. Technical advantages of the paramedian approach for lumbar epidural pun...

Different formulas have been  developed using body weight to calculate the distance (D) from the skin to the lumbar  epidural space: Depth(mm) = (weight in kg + 10) x 0.8 For example, in a 20-kg child the Depth would be calculated as follows: (20 + 10) 0.8 (30) 0.8 = 24 mm or  2.4 cm distance to the epidural space.  An alternative simpler  approximation is Depth (mm) = 1 mm/kg body weight. So in the 20-kg child D would be  20 mm or 2 cm Suresh S, Wheeler M. Practical pediatric regional anesthesia.  Anesthesiol Clin  North Am 2002;20(1):83–11 3.

Early continuous passive motion Avoid quadriceps paresis. Ambulatory Surgical results---KJL (patellar tendon) =Hamstring KJL more painful than "hamstring" Femoral nerve Block is not recommended for outpatient ACL reconstruction with "hamstring" graft.  (Frost S, arthroscopy 2000) Femoral block more indicated for KJL Catheters ... probably too much

The evidence regarding regional techniques compared with general anesthesia has been reviewed with respect to several outcomes. Seven studies of neuraxial block and six trials of peripheral nerve catheters that measured induction time showed an increase by 8 to 9 minutes in induction time associated with regional techniques.  Two of the studies showed that blocks performed in an induction room outside the operating room during the room turnover process could allow for the total anesthesia time to be competitive with general anesthesia. Two other studies looking at the utilization of block rooms showed actual reduction in induction time. The use of rapid-acting drugs, such as 2-chloroprocaine, and the presence of experienced anesthesiologists also appear to reduce the additional time required for regional techniques.  Nevertheless, the overall data indicate that there is greater time required for the performance of blocks and the onset of satisfactory analgesia. ...

The evidence regarding regional techniques compared with general anesthesia has been reviewed with respect to several outcomes. Ten studies of neuraxial blockade showed no decrease in postanesthesia care unit (PACU) time, or in the rate of PACU bypass, probably related to the persistent immobility associated with neuraxial anesthesia in the early recovery phase. In contrast, peripheral nerve blockade allowed for earlier discharge from phase 1 PACU, as well as a higher percentage of eligibility to bypass phase 1 at the end of surgery. Both neuraxial blockade and peripheral nerve block were associated with significantly lower visual analog scale (VAS) scores in the PACU, as well as a significantly reduced requirement for postoperative analgesics in the PACU. Despite better pain relief, as noted previously there was no difference in the PACU time with neuraxial blockade. With neuraxial blockade, there was a 40% reduction in nausea associated with neuraxial blockade, but this wa...

Intercostal nerve block is an effective technique to provide postoperative analgesia without central respiratory depression and to attenuate the decrease in pulmonary function after thoracic surgery. Postthoracotomy pain is not completely managed with intercostal analgesia; it requires supplemental use of parenteral opioids or NSAIDs. Intercostal nerve block can be performed intraoperatively by intrathoracic injection or percutaneously by the anesthesiologist. Nerve blocks are performed at the levels above and below the site of chest tube insertion and incision. Nerve blocks are performed by injection of 2–3 mL  of bupivacaine 0.5% with epinephrine (1:200,000 concentration). Because the average duration of these nerve blocks is 4–8 hours, placement of indwelling catheters in the intercostal space is used to provide analgesia up to 6 days Complications of this technique are few but include pneumothorax, local anesthetic toxicity, and neuroaxonal spread of local anestheti...

The femoral nerve is the largest branch of the lumbar plexus  and arises from the ventral rami of the second, third and fourth lumbar nerves. Dermatomal innervations The femoral nerve innervates the skin over the antero-medial aspect of the thigh and knee, and the medial border of the leg and medial malleolus (via the saphenous nerve). Myotomal innervations The femoral nerve innervates the following muscles: sartorius, quadriceps femoris (rectus femoris, vastus lateralis, vastus intermedius and vastus medialis), iliopsoas and pectineus. Osteotomal innervations The femoral nerve innervates the anterior wall of the hip joint, the anterior aspect of the femur and the anteromedial walls of the knee joint.

Increased awareness of TNS beginning in early 1990s Incidence dependent on type of surgery: Patient in lithotomy or gynecologic position at highest risk (≈40%). Next highest group appears to be knee arthroscopy (due to positioning and manipulation). Group with lowest incidence (4%-8%) are those having spinal anesthesia and placed in supine position ( eg , inguinal hernia repair, umbilical hernia repair). Potential causes of TNS Local anesthetic toxicity (all local anesthetics toxic) Neural ischemia related to stretching (particularly of sciatic nerve) Needle trauma, maldistribution, patient positioning, muscle spasm, and early ambulation have all been discounted as causes. Recommendation Lidocaine can be used in patients in supine, but not lithotomy position; also avoid in knee arthroscopy Uses less lidocaine than in past (rarely uses >60 mg) No difference in incidence based on needle type; dilution probably not helpful

The incidence of failed spinal after CSE is 5% ..better than old reports of 25%. 5causes for failed spinal: Smaller-gauge spinal needles with long lengths are typically used. These needles lead to slower return of CSF and a greater resistance to injection. Because the epidural needle has penetrated the tissue  planes, there is little to anchor the spinal needle in place. Although a Luer lock apparatus is available, it locks at a fixed needle length and can result in not reaching or traversing the dura. Any deviation from midline can lead to missing the dura altogether. If loss-of-resistance technique used saline, a false return of saline in the spinal needle rather than CSF can occur.it is recommended to use LOR with air . Finally, patient positioning and duration between spinal injection and completion of epidural catheter placement can change the characteristics of the spinal block Cook TM. Combined spinal-epidural techniques. Anaesthesia 2000;55:42–64. Goobie SM, M...

Epidural Test dose are as important in Children as in adults. However since epidural block always done under general anesthesia, GA decrease test dose sensitivity. For example during halothane anesthesia administration of IV adrenaline causes hypertension and bradycardia not tachycardia. Prior administration of Atropine 0.01mg/kg increase the reliability of test dose during halothane anesthesia. During Sevoflurane anesthesia, the reliability of IV adrenaline test dose 0.01mg/kg is 100% using the 10 beat per minute increase in HR as definition of positive test dose. Atropine is not needed to achieve this sensitivity. There is no data regarding test dose during isoflurane   or desflurane anesthesia  

The midline approach is most commonly used. The ligamentum   flavum is considerably thinner and less dense in infants than in older children and adults. This makes recognition of engagement in the ligament more difficult and requires both extra care and slower, more deliberate passage of the needle to avoid subarachnoid puncture. The angle of approach to the epidural space is slightly more perpendicular to the plane of the back than in older children and adults, owing to the orientation of the spinous   processes in infants and small children. The loss of resistance technique should be used, but only with saline, not air. There are several reports of venous air embolism in infants and children when air was used to test for loss of resistance Use a short (5 cm) 18-gauge Tuohy needle and a 20- or 21-gauge catheter in infants and children. Epidural kits specifically for infants and children are available Maximum of 0.4 mg/kg/hr of bupivacaine after the initial block is estab...

-Continuous spinal anaesthesia combines the advantages of single-dose spinal anaesthesia, rapid onset and a high degree of success, with those of a continuous technique. -The introduction of micro-catheters invigorated interest in the technique and allowed its expansion to additional populations and surgical procedures. However, multiple cases of cauda equina syndrome associated with micro-catheters and (primarily) hyperbaric lidocaine solution led to withdrawal of micro-catheters from the US market. -In 1992, FDA banned the use of spinal catheters thinner than 24G after 12 cases of cauda equina. 20G cathters are recommended in geriatric patients. -Continuous spinal anesthesia provides adequate level and duration of anesthesia in elderly and high risk patients undergoing lower abdominal and lower limb surgery -Indications: postoperative analgesia, chronic pain relief, previous spinal surgery, procedures of unpredictable length, significant cardiac disease, morbid obesity, difficult epi...

Although regional central conduction blockade, and especially spinal anesthesia, has been implicated in the exacerbation of MS , the studies are very small. Local anesthetic neurotoxicity has been speculated as being a more likely in nerves which are demyelinated, i.e. in MS patients. As such, theoretically epidural anesthesia may be less of a risk as concentrations of local anesthetic in the white matter of the spinal cord are lower than with spinal anesthesia Overall, however, the use of epidural anesthesia appears safe. Bader et al. noted that in women who received epidural anesthesia for vaginal delivery, relapse rates were similar to those who received local infiltration. Additional prospective and randomized studies will need to be conducted to evaluate the true relationship between regional anesthesia and MS exacerbations.

1-Decide on the highest level of innervation that will need to be blocked for the proposed surgery remembering that the underlying organs and peritoneum may come from higher spinal segments . 2- Check for lower limb weakness as an early indicator that the injection was correct. Inability to straight leg raise suggests the block will cover at least all the lumbar segments . 3- Cold can be used but will usually demonstrate blocked segments higher than those with surgical anaesthesia. Pinprick will generally be closer to the level of surgical anaesthesia . 4- To be completely happy that surgery can be performed painlessly it is wise to ensure that the level of testing to cold or pinprick is at least 2-3 segments higher than that needed. This will provide a margin for error and also ensure that the operative site does not regain sensation too quickly .