Pro/Con Debate

Awake Infants During Surgery?

In 2003, Jevtovic-Todorovic et al, showed apoptotic neurodegeneration in developing rat brains after receiving a six-hour anesthetic of oxygen, nitrous oxide and isoflurane.1

This work began the debate about neurotoxicity in neonates and infants undergoing general anesthesia. The belief that we, as pediatric anesthesiologists, could cause lifelong neurologic damage to one of our most vulnerable patient populations, led many of us to explore other anesthetic techniques. While there are other modalities utilized for general anesthesia, such as dexmedetomidine, ketamine, or propofol, this discussion will focus on a local anesthetic technique - spinal anesthesia.

Spinal anesthesia was being performed on this patient population, prior to 2000. Over the past two decades, it has increased in popularity as a method to decrease the risk of neurotoxicity.

Dr. Holman discusses spinal anesthesia for infraumbilical procedures in infants and young toddlers up to one and half years of age. She expounds on the recent growth in the field of regional anesthesia for this patient population and describes why it is an ideal anesthetic for some of these patients and procedures. Dr. Mehta and Dr. Alex describe difficulties that can occur during spinal anesthesia and possible complications and high failure rate. They illustrate, spinal anesthesia may be an option, it is definitely not for all.

The following discussion should give thought as to how we move forward and provide the optimal care for these patients and what future research needs to be done in this area.

If you have an idea for a controversial or pro-con discussion, please email your idea to Nicole Dobija at ndobija@med.umich.edu.

Nicole Dobija, MD
Mott Children’s Hospital
University of Michigan
Ann Arbor, MI

  1. Jevtovic-Todorovic V, Hartman RE, Izumi Y, et al. Early exposure to common anesthetic agents causes widespread neurodegeneration in the developing rat brain and persistent learning deficits. J Neurosci. 2003;23(3):876-882. doi:10.1523/JNEUROSCI.23-03-00876.2003

The Pro: Spinal Anesthesia for Infraumbilical Procedures in Infants Less Than 1.5 Years

By Ashlee Holman, MD
Assistant Professor
University of Michigan

Neonatal spinal anesthesia for select infraumbilical procedures is a well-studied, reliable, and safe anesthetic technique. As its name implies, this practice is commonly employed for surgeries in children less than one month of age. In addition to neonatal cases, we propose the use of spinal anesthesia for older children undergoing infraumbilical procedures, with consideration of spinal anesthesia in children up to the age of 18 months.

Historically, successful use of spinal anesthesia in children was first described in the late 1800s by Augustus Bier. Since then, spinal anesthesia in the pediatric population has waxed and waned in popularity. Spinal anesthesia resurgence occurred following development of safer local anesthetics and adjuvants to prolong spinal duration. Increased utilization has also coincided with concern for neurotoxicity related to general anesthesia in the young pediatric population. Conversely, opposition to the technique may be centered around the ease, safety, and reliability of newer general anesthetic agents, as well as inadequate training of anesthesiologists and lack of surgical buy-in.1

The positive safety profile of neonatal spinal anesthesia is well-documented and is also applicable to infant and toddler physiology. Complication rates are low, with failure, oxygen desaturation, and bradycardia occurring at rates of 5-10%, <1%, and <2%, respectively.2 Spinal anesthesia is an effective alternative to general anesthesia despite the small percentage of associated risks. Moreover, lack of exposure to potentially neurotoxic medications, decreased risk of harmful cardiovascular changes, and avoidance of intubation and pulmonary manipulation make it an ideal option for anesthesia in this patient population.

In 2017, the United States Food and Drug Administration issued a statement warning against the repeated or prolonged use of general anesthesia in children less than three years of age due to theoretical risk of neurotoxicity associated with general anesthetic agents.3 Because of this, concerns about neurotoxicity once again moved to the forefront of pediatric anesthesia, leading to increased use of techniques such as spinal anesthesia to avoid exposure to general anesthesia.

Additionally, this statement led to increased mindfulness in parents and surgeons. While several reliable studies (e.g. MASK, GAS) demonstrated no difference in neurodevelopmental outcomes after a single, short exposure to general anesthesia, the question of whether neurodevelopmental outcomes differ following longer durations of anesthesia or after multiple anesthetic exposures remains unanswered.4,5 Use of spinal anesthesia removes the exposure altogether and affords a non-neurotoxic option in lieu of general anesthesia.

Hemodynamic stability afforded by use of spinal anesthesia in the pediatric population is well-documented. Neonates receiving spinal anesthesia display minimal changes in blood pressure, heart rate, and cerebral oxygenation in comparison to those receiving general anesthesia.6 In addition, risk of hypotension, even in children with higher spinal levels, is decreased compared to general anesthesia. Furthermore, spinal anesthesia avoids intubation and preserves respiratory mechanics with decreased risk of laryngospasm, bronchospasm, and apnea, an extremely beneficial advantage in the pediatric population given the high rates of respiratory infections and associated airway problems. Avoidance of intubation and airway manipulation decreases overall anesthetic risk in children < 18 months, a population at high risk for cardiac and respiratory complications related to general anesthesia.7 For these reasons, spinal anesthesia is an ideal option for healthy infants as well as children with prematurity, lung disease, and congenital heart disease.

Children receiving spinal anesthesia also tend to receive less perioperative medications overall.8 At our institution, many undergo opioid-free surgery under spinal anesthesia. Additionally, metabolic, hormonal, inflammatory, and immune responses to surgical stress are also likely reduced secondary to the sensory and autonomic blockade afforded by spinal anesthesia.9 As with the adult population, pediatric spinal anesthesia may lead to shorter operative, anesthesia, recovery, and total hospital time as well as faster OR turnover, which translates to a reduction in costs for the hospital and patient. Moreover, these children are not receiving general anesthetic agents and, thus, are at decreased risk for experiencing emergence delirium.

At our institution, the technique of pediatric spinal anesthesia is used in neonates, infants, and toddlers for select infraumbilical procedures spanning the specialties of urological surgery, general surgery, and orthopaedic surgery. Our patients include healthy children as well as, but not limited to, those with extreme prematurity, bronchopulmonary dysplasia, congenital heart disease (including hypoplastic left heart syndrome and transposition of the great arteries), polycystic kidney disease, Hirschsprung’s Disease, Trisomy 21, and Pierre-Robin sequence.

Inclusion criteria for spinal anesthesia include procedures below the umbilicus, age less than 18 months (although we have successfully performed spinal anesthesia in children up to the age of 22 months), duration of surgery less than two hours, and parental consent. Anecdotally, since offering awake spinal anesthesia, surgeon, anesthesiologist, perioperative nursing, and parental satisfaction has been extremely high. Furthermore, our patients have anecdotally received less perioperative medications and have experienced earlier return to feeding, quicker reuniting with caregivers, and shorter operative, anesthesia, recovery, and total hospital times.

In conclusion, spinal anesthesia affords a safe and efficient alternative to general anesthesia in neonates, infants, and toddlers and should be considered a fundamental staple in pediatric anesthesia practice.

References:

  1. Tobias JD. Spinal anaesthesia in infants and children. Paediatr Anaesth 2000;10:5-16.
  2. William RK, Adams DC, Aladjem EV, et al. The Safety and Efficacy of Spinal Anesthesia for Surgery in Infants: The Vermont Infant Spinal Registry. Anesth Analg 2006;102:67-71.
  3. FDA Drug Safety Communication: FDA review results in new warnings about using general anesthetics and sedation drugs in young children and pregnant women. 2017. Available from https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-fda-review-results-new-warnings-about-using-general-anesthetics-and (accessed on July 10, 2020).
  4. Warner DO, Zaccariello MJ, Katusic SK, et al. Neuropsychological and Behavioral Outcomes after Exposure of Young Children to Procedures Requiring General Anesthesia: The Mayo Anesthesia Safety in Kids (MASK) Study. Anesthesiology 2018;129:89-105.
  5. McCann ME, de Graaff JC, Dorris L, et al. Neurodevelopmental outcome at 5 years of age after general anaesthesia or awake-regional anaesthesia in infancy (GAS): an international, multicentre, randomised, controlled equivalence trial. The Lancet 2019;393:664-77.
  6. McCann ME, Withington DE, Arnup SJ, et al. Differences in Blood Pressure in Infants After General Anesthesia Compared to Awake Regional Anesthesia (GAS Study – A Prospective Randomized Trial). Anesth Analg 2017;125:837-45.
  7. Paterson N, Waterhouse P. Risk in pediatric anesthesia. Paediatr Anaesth 2011;21:848-57.
  8. Ebert KM, Jayanthi VR, Alpert SA, et al. Benefits of spinal anesthesia for urologic surgery in the youngest of patients. J Pediatr Urol 2019;15(1):49.e1-49.e5.
  9. Wolf A. Effects of regional analgesia on stress responses to pediatric surgery. Paediatr Anaesth 2012;22:19-24.

Not Anti-Spinal but …the CON Point of View...

By Sonia Deshmukh Mehta, MD
Assistant Professor
University of Florida
and Gijo Alex, MD
Assistant Professor
UT Southwestern

Spinal anesthesia, in neonates and infants, has been performed for a variety of surgical procedures. More recently, the technique has been employed for open herniorrhaphy and pyloromyotomy. The initial draw to performing spinal anesthesia in infants was to prevent and/or minimize the risks of general anesthesia—such as intraoperative hypotension, bradycardia, and apneas. More recently, there has been a renewed interest in spinal anesthesia due to growing concerns of the long-term effects of intravenous and inhaled anesthetics on the developing brain.1

Awake regional anesthesia represents only a small percentage of all pediatric regional anesthetic techniques and is often reserved for neonates. The Pediatric Regional Anesthesia Network series documents that infant spinals represent only 1.3% of all central neuraxial blocks.2 In a survey of 47 pediatric institutions in Europe and Canada, 1262 regional blocks were performed without general anesthesia in a one-year period. In the same one-year period, 134,482 general anesthetics were performed.3 When there are limited number of awake spinal anesthetics being performed, the ability to become technically skilled and navigate through potential issues, when they arise, becomes more challenging.

There are limitations to awake regional anesthetic techniques that make it less ideal than general anesthesia. There is an excessive failure rate, inadequate duration of anesthesia, high rate of unsettled infants requiring intraoperative sedation, and inherent risks. There is also no evidence to suggest that there is any difference in neurodevelopmental outcomes when spinal anesthesia is performed alone compared to general anesthesia. In addition, the overall incidence of apnea has been shown to be comparable between both groups.4

The Vermont Infant Spinal Registry retrospectively studied 1554 patients and demonstrated that the success rate of spinal anesthesia varied. Between 2000 and 2013, the University of Vermont Medical Center almost exclusively used spinal anesthesia for infant pyloromyotomy surgery. The failure rate for attending anesthesiologists at this institution was about 2%, but this number increased to 17% for trainees who were supervised by experts in performing spinal anesthetics. It is reasonable to conclude from this data that spinal anesthesia may have an appreciable failure rate in centers without significant experience in performing this technique and/or when performed by trainees.1

In addition to the appreciable failure rate, spinal blocks have inadequate duration of anesthesia and are only useful for surgeries that are limited to less than 60 to 90 minutes. This requires that everyone in the operating room be cognizant of the time constraints and need to expeditiously complete the surgical procedure.

There is also a high rate of unsettled infants requiring intraoperative sedation for completion of surgery. The use of supplemental intravenous or mask anesthesia for a neonate is not without risks and can be challenging once a surgical procedure is underway. For example, supplemental anesthesia in infants undergoing a pyloromyotomy is an important consideration, as these infants are known to have larger gastric volumes than the general pediatric population and can be at increased risk for aspiration with supplemental anesthesia.3 There is also the potential need for emergent conversion to general anesthesia, which is not always straightforward in the neonatal and infant population.

Spinal anesthesia is not without complications, even in the most experienced hands. CSF leak has been described in a two-month old after three attempts at lumbar puncture for neuraxial anesthesia.1 Two cases of subdural hematomas have been described in infants following uneventful spinal anesthesia. Meningitis has also been cited in the literature after spinal anesthesia secondary to group B streptococcus infections. There is also potential for local anesthetic toxicity and high spinal anesthesia block. The incidence of high block culminating in respiratory compromise was reported as 1.6% in the Vermont Registry, a center that almost exclusively performs spinal anesthesia for infants for hernia repairs and pyloromyotomies.1

There are also absolute and relative contraindications to this technique that include septicemia, coagulopathy, congenital malformations or infection over the lumbar puncture site, and severe hypovolemia. Although spinal anesthesia can reduce the neuroendocrine stress response and is opioid sparing, caudal epidural, ilioinguinal nerve block, or emerging regional techniques in conjunction with general anesthesia provide similar benefits but with more prolonged postoperative analgesia.

Although there are a handful of case reports that illustrate the feasibility of performing laparoscopic surgery under spinal anesthesia, this is generally considered a relative contraindication for spinal anesthesia.

From a surgical perspective, the future of surgery has shifted from performing open procedures to laparoscopic assisted surgery. Cases that were routinely performed open, such as cholecystectomy and appendectomy, are now almost exclusively performed through laparoscopic techniques. Laparoscopic hernia repairs in neonates is technically easier, causes less tension on the spermatic cord in males, and is faster for bilateral procedures than the open technique.

As a newer generation of surgical trainees become increasingly trained in laparoscopy, the need for open hernia repairs and pyloromyotomies in neonates and infants will undoubtedly decrease--leaving even fewer opportunities for spinal anesthetics alone. And when the need for open repairs arise, the concern becomes whether or not surgeons with less experience in open techniques will be able to complete the surgery within the time frame allotted by the spinal anesthetic or with infants who are not completely immobile.

In the recent General Anesthesia Vs Spinal (GAS) study, it was demonstrated that there was no significant difference in neurocognitive outcomes two years postsurgery.4 In addition, the overall incidence of postoperative apnea (up to 12 hours postoperatively) are similar for spinal anesthesia and general anesthesia. Interestingly, there have been documented case reports illustrating that apneic events can still occur under spinal anesthesia even without the use of supplemental anesthetics.5 

In summary, although there may be certain instances where awake spinal anesthesia can provide an advantage over general anesthesia, these are few and far between. Its limited duration of action, variable success rate, and need for supplemental anesthesia are limitations that make general anesthesia a more attractive option. There is also no evidence to suggest that there is any difference in neurodevelopmental outcomes when compared to general anesthesia and similar incidence of apneas in the postoperative period.

References

  1. Disma N, Ross N, Chalkiadis G. Is spinal anesthesia in young infants really safer and better than general anaesthesia? Current Opinion Anesthesiology. Jun 2018; 31:302-307
  2. Polaner DM, Taenzer AH, Walker BJ, Bosenberg A, Krane EJ, Suresh S, Wolf C, Martin LD: Pediatric Regional Anesthesia Network (PRAN): A multi-institutional study of the use and incidence of complications of pediatric regional anesthesia. Anesth Analg 2012; 115:1353-64
  3. Ing C, Lena S, Friend A, Roh A, Lei S, Andrews H, Li G, Williams R. Adverse Events and resource utilization after spinal and general Anesthesia in infants undergoing pyloromyotomy. Reg Anesth Pain Med 2016; 41 (4): 532-537.
  4. Frawley G, Bell G, Disma N, Withington D, et al. Predictors of failure of awake regional anesthesia for neonatal hernia repair: Data from the general anesthesia compared to spinal anesthesia Study—comparing apnea and neurodevelopmental outcomes. Anesthesiology 2015: 123: 00-00.
  5. Tobias JD, Burd RS, Helikson MA. Apnea following spinal anaesthesia in two former pre-term infants. Can J Anaesth. 1998;45(10):985-989. doi:10.1007/BF03012306

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