Department of Anaesthesia,
Hotel-Dieu Hospital, Windsor, Ontario
With the advent of improved medical management of the premature neonate more and more graduates of the NICU
are presenting for elective surgery. Several reports in the surgical literature point out to us that up to 13%
of babies less than 32 wks gestational age will have an inguinal hernia; this risk jumps to 30% if the infant is
less than 1000 grams at birth. Because of the significant risk of incarceration of these hernias there is a push
to repair them surgically as soon as possible.
Unfortunately, providing safe anesthesia for these NICU babies is sometimes easier said than done. It is now well
accepted that this infant population is at higher risk for respiratory complications both intra- and post-operatively.
Higher rates of life-threatening apnea and oxygen desaturation have been documented in this population group following
general anesthesia. These facts, in combination with the increased technical difficulties encountered in working
with these babies, sometimes makes their routine surgery'' an anesthetic adventure.
Numerous authors over the years, including Gray in the Lancet (1909) and Junkin in the CMAJ (1933), have reported their experience with spinal anesthesia in infants. In a landmark paper Spinal anesthesia for surgery in the high risk infant, Dr. Abajian and his group at the University of Vermont reported their experience in providing spinal anesthesia for surgical procedures performed on NICU babies. .This paper opened up the floodgates for research and improvement in spinal anesthesia techniques for these delicate infants.
In 1982 a Level 2 NICU was first opened at the Grace Hospital in Windsor, Ontario, to service the needs of premature and critically ill neonates from Windsor and Essex County (population base 350,000). The program quickly grew and by 1988, with the arrival of a second full time Neonatologist, the NICU grew to a Level 3 facility and began to provide care to infants of 26 weeks gestational age and beyond. Up until 1986 many of these infants were transferred to London if any surgical procedures were required.. Since then a local surgeon has taken a special interest in providing surgical coverage for the NICU. Since 1990 the vast majority of anesthesia for the NICU babies at the Grace Hospital has been provided by the author using spinal anesthesia whenever possible. The following will be a brief summary of our experience.
Since 1990, 60 spinal anesthetics on 48 NICU graduates have been performed. Of the 60 surgical procedures, 55
were unilateral inguinal hernia repairs. The average gestational age of our patients was 32.4 wks. There were 26
cases performed on infants whose gestational age ranged from 25-30 wks. The average birth weight of our group was
1987 grams; 14 patients were less than 1000 grams at birth. The average post-conceptual age at surgery was 48.3
weeks. The mean weight at the time of surgery was 4346 grams with 13 patients being 3000 grams or less. Thirty
two patients (42 cases) had required mechanical ventilation at birth. .The average time on ventilator support in
the group was 22.3 days. Many of these patients had several medical problems, the most common being:
bronchopulmonary dysplasia, recurrent bronchiolitis, episodes of sepsis and jaundice.
Gradually with time and experience a preferred technique for spinal anesthesia in these patients has been developed
and will be elaborated on. My preferred technique is listed below:
Post operative monitoring in NICU is important. Oxygen saturation is critical. Overnight observation is warranted if the patient is being discharged.
A 25 gauge, 1 inch, neonatal spinal needle is preferred. Wait for CSF flow - do not move needle for five seconds post-injection.
So far, using this basic technique with some slight modifications at times, spinal anesthesia has been successful in 92% of the cases. The common complications and comparisons to other series in the literature will be discussed.
Additional Reading
C. Abajian. Spinal Anesthesia for Surgery in the High-Risk Infant. Anesth Analg
1984 63:359-363.
K. Sartorelli. Improved Outcome Utilizing Spinal Anesthesia in High Risk Infants. Journal of Pediatric Surgery, Vol 27, No 8, 1992:1022-1025.
L. Wellborn. Postoperative Apnea in Former Preterm Infants: Prospective Comparison of Spinal and General Anesthesia. Anesthesiology 72:1990:838-842.
P. Cox. Life-threatening Apnea following Spinal Anesthesia in Former Premature Infants. Anesthesiology 73:1990:345-347.
T.J. Veverka. Spinal Anesthesia Reduces the Hazard of Apnea in High Risk Infants. The American Surgeon 57:1991 ;531-535.
E.J. Krane. Postoperative Apnea, Bradycardia, and Oxygen Desaturation in Formerly Premature lnfants: Prospective Comparison of Spinal and General Anesthesia. Anesth Anaig I 995;80:7-1 3
A. Webster. Spinal Anaesthesia for Inguinal Hernia Repair in High Risk Neonates. Can J Anaesth 1991 38.281-286