Less anaesthetic and opioid is required so patients wake faster, less time is used up by recovery staff, decreases the risk of needing post-operative ventilation which can have complications especially in areas which are unfamiliar with its use. This is especially true of premature infants who are at increased risk of post op apn o ea Pediatric patients are often difficult to assess for post-operative pain. They may not be able to communicate or may be distressed for other reasons besides pain ie seperation from the mother or hunger. It is therefore difficult to titrate opioid requirements in recovery. It is better to ensure that the patient has no pain with local anaesthetic. Pain is emotionally traumatic for children and may make them anxious if they have to come back to theatre. Opioids have side effects such as nausea and vomiting and respiratory depression. Neonates and especially premature infants are particularly sensitive to the respiratory depressant effects of opioids . Effects can be difficult to predict & difficult to remember. Ie the ½ life of morphine changes rapidly over the 1 st few weeks of life. Newborns may be far more sensitive to the respiratory depressant effects as they have an immature blood brain barrier & therefore less lipophilic drugs apear more potent compared to adults. Patients may have had a nerve repair or a tendon graft and paediatric patients tend to be restless in recovery thrashing about and ruin all the work
In the neonate the intercristal line bisects L5 (cf L4 or L3/4 interspace in the adult) and the spinal cord ends at L3 in first year of life (cf L1 in the adult). As a general rule the epidural space will be found at 1 mm/kg of body weight, however, there is considerable individual variation. May be more difficult to feel loss of resistance, therefore better to use a short bevel needle Nerves in the neonate may be unmyelinated. Onset of blocks tends to be quicker. Denser blocks can be achieved with a lower concentration of local anaesthetic Children and neonates do not tend to get hypotensive after regional blocks. This is probably because children have a lower resting sympathetic tone and therefore a sympathetic block has less affect. Also a greater proportion of the blood volume is in the head so a sympathetic block of the lower limbs is less significant. Children less than 6 rarely show any change in blood pressure after spinal anaesthetic however they may have a vagal response. Children generally tolerate being awake during an operation poorly. They become restless, bored and frightened. They also tolerate painful neural blocks poorly therefore these procedures are generally done with a light general anaesthetic. Epidural fat is looser and more areolar in children so LA spreads more evenly and higher blocks can be achieved with caudal epidurals than with adults. Thee is less escape through the neaural foraminae. Block of intercostal muscles has less affect and any block affecting phrenic nerve such as an interscalene, would have a greater affect, as the infant is more dependent on the diaphragm
Spinals need to be placed as low as possible to avoid hitting the spinal cord You must be careful to avoid dural puncture in the neonate when performing caudal blocks Significant anatomic differences in comparison with adults, should be considered while utilizing regional anesthesia in children. For instance, in neonates and infants, the conus medullaris is located lower in the spinal column (at approximately the L3 vertebra) compared to adults where it is situated at approximately the L1 vertebra. This dissimilarity is a result of different rates of growth between the spinal cord and the bony vertebral column in infants. However, at approximately 1 year of age the conus medullaris reaches similar L1 level as in an adult. The sacrum of children is also more narrow and flat compared to the adult population. At birth, the sacral plate, which is formed by five sacral vertebrae, is not completely ossified and continues to fuse until approximately 8 years of age. The incomplete fusion of the sacral vertebral arch forms the sacral hiatus. The caudal epidural space can be accessed easily in infants and children through the sacral hiatus. Due to the continuous development of the sacral canal roof, there is considerable variation in the sacral hiatus. In children, the sacral hiatus is located more cephalad compared to adults. Therefore, caution is warranted when placing caudal blocks in infants as the dura may end more caudad thereby increasing the risk of accidental dural puncture. It has also been suggested that the epidural fat is less densely packed in children than in adults.5 This loosely packed epidural fat may facilitate not only the spread of local anesthestic, but it may also allow the unimpeded advancement of epidural catheters from the caudal epidural space to the lumbar and thoracic level.
The first manifestation of toxicity may be cardiovascular collapse. Peak blood levels are generally reached about 20 minutes after injection. Toxicity may occur at lower plasma concentrations than adults Paediatric patients may be at greater risk of seizures with continuous infusions It is important to administer doses incrementaly
The sacrum is the fusion of the 5 sacral vetebral bodies. The sacral hiatus is the non-fusion of the 5th sacral vetebral arch. The large bony processes on either side are the sacral cornua. The sacral hiatus is covered by the sacrococcygeal membrane. There may be variation in the anatomy due to developmental defects in sacral canal roof. The cornua can be found either 1 phalanx cephalad of the tip of the coxyx or at the bottom of an equilateral triangle The sacral canal is a continuation of the epidural space.
Full aseptic technique is used The child must be well monitored during the procedure Point bevel ventrally so that the needle will slide over the anterior plate of the sacrum. Direct the needle up the sacral canal without force so the needle does not become intra-osseus. Before injecting aspirate gently. Using excess force may collapse a vein giving a negative aspiration test. Aspirate again after 1 ml as a plug in the needle may have given a false negative aspiration test. After injecting 1/3 aspirate and wait 30 seconds. Listen for any change in heart rate Ropivicaine may be the anaesthetic of choice. This is one of the few block I may potentially be giving a lethal dose of bupivicaine Adrenalin may have the advantages of warning of intravascular injection, may improve the quality of analgesia and prolong the block in paediatric caudals Advantages of a cannula over a needle are; Confidence of placement if the cannula slides off the needle easily Possibly reduced intraosseous injection risk Possibly reduced intravascular injection risk Possibly reduced dural puncture risk
Epinephrine: The most commonly used adjuvant for single-shot caudal anesthesia is epinephrine in a concentration of 1:200,000. Epinephrine has the added benefit of serving as a marker for an inadvertent intravascular injection. Whether there is benefit for fentanyl as an additive in children undergoing single-shot caudal blockade is still debated amongst clinicians.76,77 One study found an increased incidence of nausea and vomiting when fentanyl was added to the local anesthetic solution for a single-shot caudal block.77 A dose of 2 µg/kg of fentanyl for single-shot caudal anesthesia along with the standard local anesthetic solution has been recommended for more extensive or painful procedures or in patients who have a urinary catheter in the postoperative period. The addition of 1 µg/mL to 2 μg/mL of fentanyl to 0.1% bupivacaine for continuous epidural infusions has also been used with success in neonates and children in a well monitored inpatient setting. Clonidine: Clonidine, an alpha-2 agonist, acts by stimulating descending noradrenergic medullo-spinal pathways which inhibits the release of nociceptive neurotransmitters in the dorsal horn of the spinal cord. The addition of clonidine (1 to 5 µg/kg) can improve the analgesic effect of local anesthetics for single-shot caudal blockade as well as prolong its duration of action without the unwanted side effects of epidural opioids.78 For continuous epidural infusions clonidine 0.1 µg/kg/h has been used with good effect.79 It should be cautioned that higher doses have been associated with sedation and hemodynamic instability in the form of hypotension and bradycardia, and doses as low as 2 µg/kg have been associated with postoperative sedation.80 In addition, epidural clonidine blunts the ventilatory response to increasing levels of end-tidal carbon dioxide (PCO2). Although respiratory depression does not appear to be a common problem,81 apnea has been reported in a term neonate who received a caudal block consisting of 1 mL/kg of 0.2% ropivacaine with clonidine 2 µg/kg.82 Caution should be exercised while using clonidine in very young infants due to the sedation and hypotension that may ensue. Ketamine: The addition of ketamine or S-ketamine to single-shot caudal block prolongs the analgesic effect of local anesthetics. The min disadvantage of ketamine are its psychomimetic effects. However, at low doses ( 0.25-0.5 mg/kg), ketamine is effective without noticeable behavioral side effects.78 Ketamine 1 mg/kg can also be used as an effective caudal analgesic solely without the addition of local anesthetic solution.83,84 The combination of S(+)-ketamine (0.5- 1 mg/kg) and clonidine (1 or 2 µg/kg) has shown to provide effective analgesia after inguinal herniotomy in children with prolonged duration of effect (>20 hours) without any adverse CNS effects or motor impairment.84,85 However, the safety of ketamine for central neuraxial block has been questioned, particularly with the racemic formulations that contain preservatives. Results from a small clinical trial and case series indicate a single bolus administration of preservative-free S-ketamine appears to be safe and efective.7,59 Regardless, these reports lack statistical power and detailed postoperative evaluations to draw definitive conclusions regarding the safety of ketamine for neuraxial use. An additional concern regarding use of ketamine in neonates relate to a controversial series of animal studies that suggest ketamine can produce apoptotic neurodegeneration in the developing brain.86,87 Other infant animal studies have demonstrated that ketamine may have a neuroprotective effect.88,89 Nevertheless, many anesthesiologists are hesitant to introduce caudal S-ketamine into their routine clinical practice and it is unlikely ketamine will be widely adopted in countries where preservative-free formulas are not available. v) Midazolam: Epidural midazolam (50 µg/kg), when used alone, produces postoperative analgesia without motor weakness or behavioral changes.78 This is due to its ability to inhibit GABA receptors in the spinal cord. When added to local anesthetic solutions, midazolam can prolong the duration of analgesia but this effect has not been consistently demonstrated.90 Similar to ketamine, the safety of midazolam for neuraxial use has not been established and a preservative-free formulation is not universally available.59 (vi) Neostigmine: Neostigmine (2 µg/kg) alone produces postoperative analgesia by inhibiting the breakdown of acetylcholine at muscarinic receptors in the dorsal horn.1 When combined with bupivacaine, a significant synergistic effect is observed. The addition of neostigmine (2 μg/kg) to 0.25% bupivacaine prolongs the duration of analgesia from 5 to 20 hours after hypospadias repair.1,91 However, it is associated with an unacceptably high incidence of vomiting (20-30%).91 This will likely preclude its use particularly in an ambulatory setting. Preservative–free neostigmine has not been widely available and has limited applications in pediatric regional anesthesia.
Circ can use 0.5 ml/kg Ropivicaine 2mg/ml. Good to minimize motor block in children Addition of fresh adrenaline may have some advantages ie decrease peak plasma levels, help monitor for intravascular injection and prolong the block but whether it is useful for any of these things is controversial in the literature. Other drugs that have been tried to prolong the duration of block are preservative free Clonidine and Ketamine. Ropivacaine has been extensively trialed. It should probably be used in equal doses as bupivicaine. It may offer some advantages with less motor block and improved safety with accidental intravenous injection. It is important to try and avoid lower limb motor block as most children find this distressing After a dose of 2.5mg/kg, serum levels are in the range of 0.5-1.9 mic/ml. Mean plasma levels after 3mg/kg were found to be 1.2-1.4 mic/ml Studies have shown that there is no effect on time to micturition with caudal analgesia at these doses
Failure rate higher in children older than 7 yo I/V injection probably the potentially most serious potential complication of this procedure Dural puncture (incidence estimated by Brown as 1/2000) does not cause a problem as long as it is recognized. Gentle aspiration is very important. Even a total spinal should not end in an adverse outcome as long as the patient is intubated and adequately ventilated PDPH very rare children less than 10yo Infection, sacral osteomyelitis is exceedingly rare
The ilioinguinal and iliohypogastric nerves arise from the lumbosacral plexus and together with the 12th thoracic nerve sweep anteriorly around the bowl of the ilium. At the level of the anterior superior iliac spine, the 12th thoracic and the iliohypogastric lie between the internal and external oblique muscles. The ilioinguinal lies between transversus abdominus and internal oblique and then transverses internal oblique a variable distance medial to the ASIS. The nerves supply the inguinal and suprapubic region and with the genito-femoral nerve, the lateral aspect of the scrotum. There is some cross-over inervation from the other side. The nerves do not supply the cord structures.
Pressure and massage achieves the following. LA does not disturb the tissue plains that may make surgery more difficult LA is spread evenly There is less risk of bruising or haematoma
Either 0.5% or 0.25% Bupivicaine can be used depending on whether the block is bilateral or combined with a caudal, to keep total dose less than 3 mg/kg Studies have shown that plasma levels are well within safe limits with these doses
Excessive fluid may make it difficult for the surgeon to discect out tissue plains. This can be avoided by keeping volumes down and by massaging the site after injection. The femoral nerve is blocked in about 5% of cases. The child will be unable to flex his/her hippocampus. This requires only reassurance as it will wear off as the local anaesthetic wears off. Occurs if the injection is too deep.
The dorsal nerve of the penis arises from the pudendal nerve which arises from the sacral plexus (S234). The dorsal nerves of the penis arises as paired nerves on the dorsal side of the corpus cavenosum under the Symphysis Pubis under Bucks fascia. At the base of the penis, these nerves divide into multiple filaments that encircle the shaft before reaching the glands. They lie alongside the atery and veins of the penis. The base and the proximal part of the penis are supplied by the genitofemoral and ilioinguinal nerves.
Vital that no adrenaline containing solutions are used as the penis is an end organ and adrenaline may cause necrosis of the tip Dose 1ml + 0.1 ml/kg The ventral tip of the glans may be missed by a dorsal nerve of the penis block only Alternatively a ring block may be performed or S/C infiltration at 10 and 2 oclock positions at the base of the penis The glans may also be covered with EMLA cream, lignocaine Gel or a lignocaine spray
Be prepared to do an alternative technique if it is not working There has been a report of gangrene of the tip of the penis, probably due to haematoma and vascular compromise. The advantage of the 1st technique described is that the needle is away from nerves and vessels and the block depends on diffusion of LA 9 incidents were recorded out of 3909 DNP blocks (0.2%). This included two cases of bleeding from the prepuce, two urethral injuries, three haematomas and two drug errors. Two cases required further surgical intervention but all of the patients recovered with no apparent long-term sequelae[1]. DPNB was used in 1022 (84%) of the circumcisions. Complications occurred in 12 cases (11 with small ecchymoses at injection sites and one with excessive bleeding from the needle stick), for a rate of 1.2%. No cases of lidocaine toxicity, voiding delay, or vascular compromise were noted. There was a trend toward increased incidence of injection-site hematomas with the Plastibell as compared with the Gomco technique (P = .07). There were no significant differences in complication rates for DPNB performed by less experienced operators (eg, medical students and residents) compared with more experienced operators (staff physicians). CONCLUSIONS. This study corroborates findings of smaller case studies, indicating that DPNB is associated with a low rate of minor complications[2]. Minor complications have included edema of the foreskin and transient ischemia of the skin of the glans penis[3]. Infections have been reported anecdotally including infection of the penis[4], osteomyelitis of the ischium[5] and scrotal abcess
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