**7. Local anesthetics**

The most commonly used LA are 0.5% bupivacaine and tetracaine, at doses of 0.3–0.6 mg/kg. Although ropivacaine and levobupivacaine are also safe and effective agents. Ropivacaine 0.5% at doses of 0.5–1 mg/kg, produce a good quality block. With ropivacaine, the motor block is significantly shorter and less intense than with bupivacaine. Levobupivacaine 0.5% at a dose of 0.3–1 mg/kg, is also used clinically with a less intense motor block, similar to ropivacaine.

Bupivacaine, ropivacaine, and levobupivacaine are drugs that are broken down by enzymes in the liver. Therefore, they should be used carefully in PNB because they have a lower capacity to metabolize both anesthetics due to their immaturity [17]. Term NB metabolize LA well, but not preterm infants or patients with other comorbidities.

The duration of action of all spinal LA is one of the great limitations of using this route, since its duration is relatively short, it does not exceed 80 minutes in most of them. Postoperative analgesia is very short. For this reason, many clinicians have used so-called LA adjuvants such as adrenaline, morphine, or fentanyl, to prolong its duration. Most of them manage to extend the duration of action for a time no longer than 30%. However, their safety is questionable due to the possible toxicity of the adjuvants to the development of the spinal cord, which can be vulnerable. Intrathecal medications can allow the development of toxicity by altering the neuronal activity of the spinal cord [18–20].

#### **8. Complications of spinal block**

The complications of SA in children are similar to those in adults. However, the evaluation of signs and symptoms is difficult to identify, especially in NB or younger than one year compared to older children. Physiological and behavioral changes rather than verbal ones manifest their conditions.

The main complications of SA may result from the technique used or from the action of the LA itself. In general, the incidence of side effects is low and permanent secondary sequelae have not been reported in most clinical studies. They are shown in **Table 2** [14].

Complications include headache and low back pain, neurological complications, nausea, vomiting, and cardiorespiratory changes. Elevated levels of spinal block, above T4, reduce the expansion movement of the lower rib cage, decreasing intercostal muscle activity and paradoxical respiratory movements may occur.


**Table 2.**

*Complications of spinal block in children [14].*

Monitoring of oxygen saturation and an oxygen source are necessary. Post-puncture headache is the most frequent complication, it has an incidence of 3 to 4%, even with the use of spinal needles 25–27, and the incidence increases with spinal needles number 22. The headache appears in the first 24 hours post-puncture and may be unilateral or bilateral. It worsens with changes in position from lying to sitting and some children may manifest nausea and vomiting, which may be accompanied by blurred vision, vertigo, and tinnitus. These symptoms usually disappear spontaneously in three to five days, and in some children, they can continue for several more days. Caffeine is the pain reliever of choice in children [21].

#### **9. Spinal anesthesia and short-stay surgery**

Another reason to prefer SA in the child is the low cost compared to GA, in addition to the rapid recovery from short-stay surgery and early return home. These advantages include a rapid recovery derived from the short duration of SA with rapid recovery of mobility of the lower extremities, and prompt restoration of the oral route, with a low incidence of postoperative nausea and vomiting [22].

#### **10. Sedation**

Sedation is often used in the child, for the application of the spinal puncture. The goal of sedation is to produce anxiolysis and to ensure that the child remains motionless during the lumbar puncture. Movement during puncture can cause significant trauma to neurovascular structures. Midazolam, ketamine, propofol, dexmedetomidine, or inhaled sevoflurane can be used. However, any of them can be associated with periods of apnea. The safest are inhaled agents like sevoflurane. Dexmedetomidine produces a natural sleep state and produces anxiolysis and analgesia. Sedatives should be avoided in preterm, weak or high-risk newborns [15].

#### **11. Discussion**

SA has been used for a variety of surgical procedures, including inguinal hernia, exploratory laparotomy, omphalocele, and gastroschisis repair, multiple orthopedic procedures mainly of the lower extremities, pylorotomy, and surgery of the anus, bladder, and penis. Epidemiological data show that newborns have a higher risk of complications associated with GA. In multiple studies, the technique that has shown

#### *Spinal Anesthesia in Pediatrics DOI: http://dx.doi.org/10.5772/intechopen.100590*

efficacy and safety and that has avoided the use of general anesthesia in the group of preterm, ex-preterm, or high-risk patients has been SA. Most clinicians prefer SA because it is associated with great respiratory and cardiovascular stability, allowing greater survival for newborns. In large study populations on the usefulness of SA, it has been shown that oxygen desaturation of <90% is rarely observed, and < 5% of newborns require supplemental oxygen, although neonates are notoriously susceptible to present hypoxia in response to external stimuli such as surgical stress.

The incidence of apnea in the NB in the first 12 hours postoperatively associated with GA, ranges between 10% and 30%. This seems to be directly related to prematurity and general anesthetics, 70% of apnea is of central origin, 10% obstructive and 20% combined. To the multiple advantages of SA in children, we can add postoperative analgesia with a short hospital stay, a lower cost for the hospital, and a lower incidence of mechanical ventilation after surgery [14, 15, 17, 23].
