Correspondence / Journal of Pediatric Surgery 49 (2014) 1872–1874
More on caudal anesthesia for high risk ex-premature infants
1873
- 2 of those 7 cases also presented with a short-lasting episode of apnea in the PACU: which resolved either spontaneously or with gentle stimulation. - No late postoperative apnea episode was observed.
Dear Editor, We read with great interest the retrospective review of 71 cases comparing caudal anesthesia with sedation with general anesthesia for inguinal herniorraphy in high risk neonates published recently by Balent et al. [1]. Although awake spinal or caudal blockade is recommended to provide safe anesthesia to ex-premature infants undergoing inguinal hernia repair, many anesthesiologists prefer adding light general anesthesia because 1) awake spinal block carries a risk of failure, either directly or because the block wears off too quickly; 2) an awake infant sometimes needs some sedation (sugar, nitrous oxide, midazolam etc.) in order to remain still during the surgical procedure even if the block is excellent and 3) because it is easier to perform a regional block on an immobile target. Moreover, the advantages of awake regional anesthesia by comparison with modern general anesthesia are not evident [2]. We would like to make some comments about the two techniques described and propose some alternatives. First, we were surprised to read that no regional block technique (caudal or ilioinguinal block, for example) was used in the GA group in order to avoid or reduce fentanyl use. Second, the dose of ketamine and midazolam administered IM in the caudal group was quite high and probably resulted in very deep sedation or general anesthesia in some cases: this probably explains some of the intraoperative or postoperative events observed in 24% of the patients. In fact, caudal anesthesia can be associated with other agents, resulting in titratable light general anesthesia. For example, the team in Vienna uses IV sedation with nalbuphine 0.1 mg·kg − 1 and propofol 1 mg·kg − 1 (with supplemental doses of propofol 0.5 mg·kg − 1 if necessary) before performing a caudal block with 1 ml.kg − 1 of ropivacaine 0.2%. All infants were spontaneously breathing and received a mixture of oxygen in air by facemask. In the 89 infants born prematurely reported in their publication [3], 47 were operated upon before 46 weeks postconceptual age and received prophylactic caffeine to prevent postoperative apnea. Intraoperatively, 4 experienced apnea, 2 laryngospasm and 2 stridor: all these events were easily managed with short bag-valve-mask ventilation. In our center, we prefer using an inhalation agent such as sevoflurane because its effects on consciousness, ventilation and upper airway muscles are shorter lasting than those of IV anesthetics. The following technique has been used in close to 250 infants thus far with neither major morbidity nor mortality. Anesthesia is induced with sevoflurane and an intravenous line is inserted as soon as the baby loses consciousness. A caudal block is performed in the lateral decubitus position with 1 ml·kg − 1 ropivacaine 0.2% with epinephrine 1/400.000. The infant is turned supine as soon as the injection is completed. A light level of anesthesia is thereafter maintained with sevoflurane around 2% in a mixture of air and oxygen administered via a facemask and a Mapleson D breathing circuit. Surgery starts approximately 10 minutes after the caudal injection. Great care is taken to preserve the infant's spontaneous breathing but ventilation can easily be assisted if necessary. The goals are: avoiding the possible psychological stress of an awake procedure to the infant, providing an immobile target to the anesthesiologist performing the block and preserving the baby's respiratory drive (32 less than 31 weeks gestational age) [4]: - Caudal blockade was successful in 99% of cases. - An intraoperative episode of apnea occurred in 7 cases: all presented with at least one comorbidity and the episode was easily managed by bag- mask ventilation.
Based on animal studies, there are possible deleterious cerebral effects (neuroapoptosis) when general anesthetics are administered to neonates and young infants. Changes in physiologic variables such as blood pressure, paCO2, blood glucose level etc. could also contribute to these effects. A prospective multicentric study (under the acronym: GAS) is currently underway to evaluate both the immediate and late effects of awake regional versus general anesthesia for hernia repair in ex-premature infants. Until its results are known, we think that combining light general anesthesia that preserves the infant's respiratory drive with a regional block that allows avoidance of opiates and muscle relaxants is a safe solution in experienced hands.
Francis Veyckemans Service d'Anesthésiologie, Cliniques universitaires St Luc Avenue Hippocrate 10-1821, B-1200 Brussels, Belgium Corresponding author. Tel.: +32 2764 1821; fax: +32 2764 3699 E-mail address: [email protected] Dominique Lacrosse Service d'Anesthésiologie, CHU Mont-Godinne Dinant Avenue Therasse, B-5530 Yvoir, Belgium Thierry Pirotte Service d'Anesthésiologie, Cliniques universitaires St Luc Avenue Hippocrate 10-1821, B-1200 Brussels, Belgium http://dx.doi.org/10.1016/j.jpedsurg.2014.09.073
References [1] Balent E, Edwards M, Lustik M, et al. Caudal anesthesia with sedation for inguinal hernia repair in high risk neonates. J Pediatr Surg 2014;49:1304–7. [2] Walther-Larsen S, Rasmussen LS. The former preterm infant and risk of postoperative apnoea: recommendations for management. Acta Anaesthesiol Scand 2006;50:888–93. [3] Brenner L, Kettner SC, Marhofer P, et al. Caudal anesthesia under sedation: a prospective analysis of 512 infants and children. Br J Anaesth 2010;104:751–5. [4] Lacrosse D, Pirotte T, Veyckemans F. Caudal block and light sevoflurane mask anesthesia in high-risk infants: an audit of 98 cases. Ann Fr Anesth Reanim 2012;31: 29–33.
Reply to Letter to the Editor
Dear Editor, We appreciate the opportunity to respond to the comments made by Dr. Veckemans, Lacrosse, and Pirotte regarding our article “Caudal anesthesia with sedation for inguinal hernia repair in high risk neonates.” [1] We were delighted to see remarks from providers who, like ourselves, champion the technique of regional anesthesia with sedation in this high risk group of neonates. The decision surrounding the best time to repair an inguinal hernia in a preterm infant remains a vexing one and continues to be a source of debate for pediatric surgeons. Regional anesthesia, if proven superior to general, could sway the course of this debate. The addition of sedation, or “light anesthesia” as the authors call it, is an attractive one. We concur that, compared to performing the technique under a pure spinal anesthetic, sedation allows for more optimal conditions for placing the block, and if needed, for placing the intravenous line and the
More on caudal anesthesia for high risk ex-premature infants
1873
- 2 of those 7 cases also presented with a short-lasting episode of apnea in the PACU: which resolved either spontaneously or with gentle stimulation. - No late postoperative apnea episode was observed.
Dear Editor, We read with great interest the retrospective review of 71 cases comparing caudal anesthesia with sedation with general anesthesia for inguinal herniorraphy in high risk neonates published recently by Balent et al. [1]. Although awake spinal or caudal blockade is recommended to provide safe anesthesia to ex-premature infants undergoing inguinal hernia repair, many anesthesiologists prefer adding light general anesthesia because 1) awake spinal block carries a risk of failure, either directly or because the block wears off too quickly; 2) an awake infant sometimes needs some sedation (sugar, nitrous oxide, midazolam etc.) in order to remain still during the surgical procedure even if the block is excellent and 3) because it is easier to perform a regional block on an immobile target. Moreover, the advantages of awake regional anesthesia by comparison with modern general anesthesia are not evident [2]. We would like to make some comments about the two techniques described and propose some alternatives. First, we were surprised to read that no regional block technique (caudal or ilioinguinal block, for example) was used in the GA group in order to avoid or reduce fentanyl use. Second, the dose of ketamine and midazolam administered IM in the caudal group was quite high and probably resulted in very deep sedation or general anesthesia in some cases: this probably explains some of the intraoperative or postoperative events observed in 24% of the patients. In fact, caudal anesthesia can be associated with other agents, resulting in titratable light general anesthesia. For example, the team in Vienna uses IV sedation with nalbuphine 0.1 mg·kg − 1 and propofol 1 mg·kg − 1 (with supplemental doses of propofol 0.5 mg·kg − 1 if necessary) before performing a caudal block with 1 ml.kg − 1 of ropivacaine 0.2%. All infants were spontaneously breathing and received a mixture of oxygen in air by facemask. In the 89 infants born prematurely reported in their publication [3], 47 were operated upon before 46 weeks postconceptual age and received prophylactic caffeine to prevent postoperative apnea. Intraoperatively, 4 experienced apnea, 2 laryngospasm and 2 stridor: all these events were easily managed with short bag-valve-mask ventilation. In our center, we prefer using an inhalation agent such as sevoflurane because its effects on consciousness, ventilation and upper airway muscles are shorter lasting than those of IV anesthetics. The following technique has been used in close to 250 infants thus far with neither major morbidity nor mortality. Anesthesia is induced with sevoflurane and an intravenous line is inserted as soon as the baby loses consciousness. A caudal block is performed in the lateral decubitus position with 1 ml·kg − 1 ropivacaine 0.2% with epinephrine 1/400.000. The infant is turned supine as soon as the injection is completed. A light level of anesthesia is thereafter maintained with sevoflurane around 2% in a mixture of air and oxygen administered via a facemask and a Mapleson D breathing circuit. Surgery starts approximately 10 minutes after the caudal injection. Great care is taken to preserve the infant's spontaneous breathing but ventilation can easily be assisted if necessary. The goals are: avoiding the possible psychological stress of an awake procedure to the infant, providing an immobile target to the anesthesiologist performing the block and preserving the baby's respiratory drive (32 less than 31 weeks gestational age) [4]: - Caudal blockade was successful in 99% of cases. - An intraoperative episode of apnea occurred in 7 cases: all presented with at least one comorbidity and the episode was easily managed by bag- mask ventilation.
Based on animal studies, there are possible deleterious cerebral effects (neuroapoptosis) when general anesthetics are administered to neonates and young infants. Changes in physiologic variables such as blood pressure, paCO2, blood glucose level etc. could also contribute to these effects. A prospective multicentric study (under the acronym: GAS) is currently underway to evaluate both the immediate and late effects of awake regional versus general anesthesia for hernia repair in ex-premature infants. Until its results are known, we think that combining light general anesthesia that preserves the infant's respiratory drive with a regional block that allows avoidance of opiates and muscle relaxants is a safe solution in experienced hands.
Francis Veyckemans Service d'Anesthésiologie, Cliniques universitaires St Luc Avenue Hippocrate 10-1821, B-1200 Brussels, Belgium Corresponding author. Tel.: +32 2764 1821; fax: +32 2764 3699 E-mail address: [email protected] Dominique Lacrosse Service d'Anesthésiologie, CHU Mont-Godinne Dinant Avenue Therasse, B-5530 Yvoir, Belgium Thierry Pirotte Service d'Anesthésiologie, Cliniques universitaires St Luc Avenue Hippocrate 10-1821, B-1200 Brussels, Belgium http://dx.doi.org/10.1016/j.jpedsurg.2014.09.073
References [1] Balent E, Edwards M, Lustik M, et al. Caudal anesthesia with sedation for inguinal hernia repair in high risk neonates. J Pediatr Surg 2014;49:1304–7. [2] Walther-Larsen S, Rasmussen LS. The former preterm infant and risk of postoperative apnoea: recommendations for management. Acta Anaesthesiol Scand 2006;50:888–93. [3] Brenner L, Kettner SC, Marhofer P, et al. Caudal anesthesia under sedation: a prospective analysis of 512 infants and children. Br J Anaesth 2010;104:751–5. [4] Lacrosse D, Pirotte T, Veyckemans F. Caudal block and light sevoflurane mask anesthesia in high-risk infants: an audit of 98 cases. Ann Fr Anesth Reanim 2012;31: 29–33.
Reply to Letter to the Editor
Dear Editor, We appreciate the opportunity to respond to the comments made by Dr. Veckemans, Lacrosse, and Pirotte regarding our article “Caudal anesthesia with sedation for inguinal hernia repair in high risk neonates.” [1] We were delighted to see remarks from providers who, like ourselves, champion the technique of regional anesthesia with sedation in this high risk group of neonates. The decision surrounding the best time to repair an inguinal hernia in a preterm infant remains a vexing one and continues to be a source of debate for pediatric surgeons. Regional anesthesia, if proven superior to general, could sway the course of this debate. The addition of sedation, or “light anesthesia” as the authors call it, is an attractive one. We concur that, compared to performing the technique under a pure spinal anesthetic, sedation allows for more optimal conditions for placing the block, and if needed, for placing the intravenous line and the
