Awake Infant Spinal
Indications: Pyloromyotomy (open), umbilical hernia repair (open), colostomy, inguinal herniorrhaphy (open), chordee correction, hypospadias repair, hydrocelectomy, orchiopexy, cystoscopy, circumcision, lower extremity muscle biopsy, lower extremity closed reductions, tendon lengthening, club foot repair, lower extremity polydactyly, laparoscopic abdominal procedures (experienced institutions)
Special Considerations: Surgical team agreement (lack of muscle relaxation, time constraint); Surgical time, including preparation & draping, between 60-120 minutes with a mean of 90 minutes; Equipment availability (1.5 inch spinal needles (22g or 25g))
Patient Population: Infants < 10 kg or < 1 years old*; former preterm infants or infants with increased risk of postoperative apnea following general anesthesia; infants with existing anomalies (airway, cardiac, pulmonary) for whom general anesthesia may pose an increased risk of adverse events.
*Spinal anesthesia may successfully be utilized in older children, however this often requires sedation for spinal placement and intraoperative management.
Benefits: Hemodynamic stability (preserved intraoperative systolic blood pressure), decreased incidence of postoperative apnea, reduced neuroendocrine stress response following major abdominal surgery, preservation of natural airway, reduced PACU time, earlier oral postoperative nutrition, increased parental satisfaction, decreased operating room time, more cost-effective compared to general anesthesia, reduced greenhouse gas emissions
Contraindications: Lack of parental consent, lack of surgical team agreement, operative time greater than 120 minutes, local infection at the lumbar puncture site, systemic infection, severe anatomical deformities, increased intracranial pressure, coagulopathy
Complications: failed spinal requiring supplemental sedation and possible conversion to GA with airway manipulation, high spinal requiring tracheal intubation, LAST, hematoma, infection, post dural puncture headache (extremely rare in infants)
Medications and Doses:
Isobaric Bupivacaine: 0.5%: 0.8 - 1.0 mg/kg (infants < 5kg dosed at the higher end); can provide 60-80 minutes of motor blockade
Hyperbaric Bupivacaine: 0.75% in 8.25% dextrose: 0.8 - 1.0 mg/kg; can provide 60-80 minutes of motor blockade
Adjuvant - Epinephrine: “epinephrine wash” of the syringe; can provide additional 20 minutes of motor blockade as well as rapid recognition of intravascular injection
Adjuvant - Clonidine: 1 mcg/kg added to bupivacaine; can provide additional 40 minutes of motor blockade and additional 1-2 hours analgesia (2mcg/kg may cause reduction in blood pressure and greater postoperative sedation)
Technique
Optional: 4% topical lidocaine ointment or EMLA to site 15-30 mins prior to planned spinal
Optional: pre-procedure intravenous access (dependent on provider practice; option to safely place IV in the lower extremity AFTER spinal is performed)
Apply standard ASA monitors including pulse oximetry, EKG, blood pressure cuff; ensure spinal tray and medications are prepared (medication drawn up in TB syringe, pediatric spinal needle x 2, betadine with sterile gauze). Some will even prepare two doses in the event of an injection malfunction
MOST CRITICAL - Patient sitting upright and in position with assistance of “holder” (anesthesiologist/CRNA/RN/surgeon) - see images below for positioning
Remove topical anesthetic if applied. Identify iliac crests, identify midline, and locate L3-L4 or L4-L5 interspace. Mark with fingernail
Cleanse area with betadine using sterile technique
Confirm landmarks and perform lumbar puncture with 1.5 inch 22g quinke or 25g whitacre spinal needle at the lowest easily palpable interspace (Tip: initial skin puncture may cause infant to fuss; pause to allow infant to settle prior to further advancement)
Advance spinal needle until “pop” of ligamentum flavum and dura. Note: ligaments and dura are softer with less tactile feedback; check frequently for CSF return (Tip: epidural space is typically 1mm/kg; it is easy to advance too far. If deep - remove stylet, and slowly retract spinal needle until CSF flow or out of skin)
Once free and clear CSF flow is obtained, inject prepared medication. Aspiration not recommended to prevent dilution of volume/loss of intrathecal access
Immediately remove spinal needle and lay infant supine (to avoid saddle block), with head slightly elevated (to avoid high spinal) (Tip: towel rolled under shoulders to keep head elevated; lift infant in air for electrocautery pad rather than leg lift)
Successful spinal indicators include loss of motor tone of lower extremities, lack of sensation of lower extremities (IV placement), bowel movement
Positioning (Seated)
Holder will stand in front of the seated infant. While supporting the head and neck against their chin or chest, the holder will place their thumbs along the infant’s shoulders, with the 2nd and 3rd digits holding the lateral aspect of the infant’s arms down. While pushing the shoulders down, flexion can be achieved by wrapping the 4th and 5th digits along the posterior aspect of the infant’s thighs.
Can be modified to infant size and/or holder dexterity
Recruitment of 2 people as holders may be necessary for additional support
Rolling a towel or blanket under the flexed knees can help in older infants (pictured)
If the infant is small enough, they can be seated in a foam donut pillow (pictured)
Positioning (Lateral Recumbent):
The holder will place the infant in the lateral recumbent position, flexing the head, hips, and knees (L3) to create the largest interspinous distance.
Additional Suggestions:
The seated position may allow for higher success rates of spinal placement
Perform the procedure with disposable chucks under the infant to allow for rapid clean up (cleaning solution, bowel movement, etc)
Create swaddle to contain infant arms
Use of ether screen for lower drapes/access to awake infant
Sucrose on pacifier for procedure
Motor block wears off before sensory block; if lower extremities are active with a few minutes to spare, can supplement with IV dexmedetomidine, IV propofol, and/or inhaled volatile anesthetic
Spinal anesthesia is by no means a recent development; it was first described in 1898 by August Bier who referred to it as the “cocainization of the spinal cord.” Only a decade later in 1909 Lord H. Tyrell Gray published “A study of spinal anesthesia in children and infants,” advocating for use of spinal anesthesia in infants requiring surgical procedures. However, as general anesthetics evolved over time, their safety and efficacy rendered general anesthesia the technique of choice with spinal anesthesia falling out of favor. In the world of pediatric anesthesia, spinals reappeared only in the 1980s when Abajian et al described “Spinal anesthesia for surgery in the high risk infant.” In this premature and ex-premature patient population general anesthesia is associated with significant increased risk of postoperative apnea, making spinal anesthesia an advantageous alternative.
Anatomical and physiologic considerations however must be recognized to safely practice the use of spinal anesthetic technique in the infant. The spinal cord in the infant terminates at L3 as opposed to L1/L2 in the adult and as such lumbar puncture should be performed below this level. Additionally, infants have both an increased amount of CSF per kg and a higher rate of turnover as well as increased systemic absorption secondary to higher cardiac output necessitating a higher dose of local anesthetic to achieve successful blockade as well as shorter block duration. Thus, to achieve longer block time adjuvants can be utilized. Alternative techniques including threading of a caudal catheter in addition to spinal dose may also prove beneficial for longer procedures.
Unlike in adults, where spinal anesthesia is associated with significant hemodynamic effects, younger children (< 6 years old) including neonates do not display these changes. Oberlander et al in examined the potential autonomic regulatory mechanisms that may account for the lack of decrease in systolic blood pressure and heart rate, concluding that sympatholysis is offset by a withdrawal of cardiac vagal activity. Smaller venous capacitance with less venous pooling also likely contributes.
In conclusion, awake spinal anesthesia is a safe and effective alternative to general anesthesia for infants. It is a technique that can easily be learned and mastered by pediatric anesthesiologists to provide an elegant anesthetic when implemented for the right patient and procedure.
Bier, A. Versuche über Cocainisirung des Rückenmarkes. Deutsche Zeitschrift f. Chirurgie 51, 361–369 (1899). https://doi.org/10.1007/BF02792160
Gray, H.T., 1909. A STUDY OF SPINAL ANESTHESIA IN CHILDREN AND INFANTS.: FROM A SERIES OF 200 CASES. The Lancet, 174(4491), pp.913-917. Vancouver
Abajian, J. C., Mellish, R. P., Browne, A. F., Perkins, F. M., Lambert, D. H., & Mazuzan Jr, J. E. (1984). Spinal anesthesia for surgery in the high-risk infant. Anesthesia & Analgesia, 63(3), 359-362.
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Heydinger, G., Kim, S. S., Beltran, R. J., Veneziano, G., Smith, A., Tobias, J. D., & Uffman, J. C. (2022). Ambulatory spinal anesthesia in infants≤ six months of age: A retrospective review of outcomes and safety. Journal of Clinical Anesthesia, 81, 110920.
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Oberlander, T. F., Berde, C. B., Lam, K. H., Rappaport, L. A., & Saul, J. P. (1995). Infants tolerate spinal anesthesia with minimal overall autonomic changes: analysis of heart rate variability in former premature infants undergoing hernia repair. Anesthesia and analgesia, 80(1), 20–27.
Oulego-Erroz, I., Mora-Matilla, M., Alonso-Quintela, P., Rodríguez-Blanco, S., Mata-Zubillaga, D., & de Armentia, S. L. L. (2014). Ultrasound evaluation of lumbar spine anatomy in newborn infants: implications for optimal performance of lumbar puncture. The Journal of Pediatrics, 165(4), 862-865.
Whitaker, E. E., Chao, J. Y., Holmes, G. L., Legatt, A. D., Yozawitz, E. G., Purdon, P. L., ... & Williams, R. K. (2021). Electroencephalographic assessment of infant spinal anesthesia: A pilot prospective observational study. Pediatric Anesthesia, 31(11), 1179-1186.
