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A case of cerebrospinal fluid leak in an infant after spinal anesthesia
Journal of Clinical Anesthesia 25 (2013) 217–219
Contents lists available at SciVerse ScienceDirect
Journal of Clinical Anesthesia journal homepage: www.JCAfulltextonline.com
Case Report
A case of cerebrospinal fluid leak in an infant after spinal anesthesia☆,☆☆ Joy I. Allee MD (Fellow in Anesthesia) a, Kathryn M. Goins MD (Fellow in Anesthesia) a, Charles B. Berde MD, PhD (Professor of Anaesthesia) a, b, Mary Ellen McCann MD, MPH (Associate Professor of Anaesthesia) a, b,⁎ a b
Department of Anesthesiology, Perioperative and Pain Medicine, Children's Hospital Boston, Boston, MA 02115, USA Department of Anaesthesia, Harvard Medical School, Boston, MA 02115, USA
a r t i c l e
i n f o
Article history: Received 4 April 2012 Received in revised form 11 July 2012 Accepted 21 July 2012 Keywords: Anesthesia Pediatric Cerebral spinal fluid Infant Spinal anesthesia: Complication
a b s t r a c t A 2 month old, 51 kg female infant underwent neuraxial anesthesia for repair of a right inguinal hernia. After two unsuccessful attempts at obtaining free-flowing cerebrospinal fluid (CSF) in the L3-L4 lumbar interspace with a 25-gauge (G) neonatal spinal needle, clear CSF was obtained using a Quincke 22-G needle. After easy aspiration, a total of 0.7 mL of 0.75% hyperbaric bupivicaine was injected intrathecally. Immediately after the spinal block, a caudal epidural block was placed by injecting 2 mL of 0.25% bupivacaine with 1:200,000 using a 22-G Quincke spinal needle. Surgery and recovery were uneventful. Two days later, after a crying spell, a bulging, grape size swelling was noted in the infant’s lumbar region. Examination was normal except that her fontanel was mildly depressed when she was upright, and a 1 - 1.5 cm soft, nontender swelling in her lumbar area bulged out when she strained. The bulge resolved over the next 48 hours. In the majority of neonates, CSF leaks into the epidural space after lumbar puncture. In our case, the patient showed CSF accumulation at the site of puncture. © 2013 Elsevier Inc. All rights reserved.
1. Introduction For infants, spinal anesthesia is gaining acceptance as an alternative to general anesthesia [1]. After consultation with our Office of Clinical Investigation and consent by the parents, we report the rare occurrence of subcutaneous cerebrospinal fluid (CSF) accumulation at the puncture site of a 2 month old infant, two days after a spinal anesthetic was performed. 2. Case report A 5.1 kg, former term and otherwise healthy, 2 month old infant girl presented for right inguinal herniorrhaphy and laparascopic exploration of the left side. On discussion of a general versus neuraxial (spinal and caudal) anesthetic technique, the parents agreed on the latter anesthetic option. The infant was brought back to the operating room, standard ASA monitors were applied, and intravenous access was established. The infant was positioned sitting for placement of the spinal anesthetic. After a sterile prep and drape, a 25-gauge (G), 2.54 ☆ None of the authors has any financial relationships related to this publication. ☆☆ Presented in part at the Winter Meeting of the Society for Pediatric Anesthesia/ American Academy of Pediatrics (SPA/AAP), Tampa, FL, Feb. 23-26, 2012. ⁎ Correspondence: Mary Ellen McCann, MD, MPH, Department of Anesthesiology, Perioperative and Pain Medicine, Children’s Hospital Boston, 300 Longwood Ave., Boston, MA 02115, USA. Tel.: +1 617 355 7737. E-mail address: [email protected] (M.E. McCann). 0952-8180/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jclinane.2012.07.008
cm neonatal spinal needle was introduced at the L3-L4 lumbar interspace. Two atraumatic passes were attempted without freeflowing CSF. At this time, since the infant was agitated, it was decided to reattempt at the same level using a 22-G, 3.8 cm pediatric Quincke spinal needle. On the first attempt, there was free-flowing, clear, nonbloody CSF. After easy aspiration, a total of 0.7 mL of 0.75% hyperbaric bupivicaine was injected intrathecally. The procedure was uncomplicated; the infant was placed first in reverse Trendelenburg position, then positioned in right lateral decubitus for the caudal anesthetic. A 22-G Quincke spinal needle was used to find the caudal epidural space with negative aspiration of CSF and blood. A total of 2 mL of bupivicaine 2.5 mg/mL solution with epinephrine 5 μg/mL was easily injected incrementally with no evidence of electrocardiographic (ECG) changes. The surgical procedure was completed without incident, and the patient went home later that day with no concerns. Two days later, after the infant’s crying spell, her parents noted a bulging, grape-sized subcutaneous swelling in the patient’s back, in the area of the spinal needle entry site. The bulge increased in size each time the infant cried. The skin over the site appeared intact. She was also more irritable when being held upright. There was no evidence of fevers, erythema, or discharge at the site. The patient was brought to the emergency department for evaluation. She was noted to be a happy, well-appearing infant with a nonfocal neurological examination. Her fontanel was mildly depressed when upright, but flat when she was lying supine. A 1 to 1.5 cm soft, nontender, nonerythematous swelling was noted in the lumbar area, which
218
J.I. Allee et al. / Journal of Clinical Anesthesia 25 (2013) 217–219
Fig. 1. View of the 1 × 1.5 cm swelling (arrow) over the L3-L4 interspace, with infant in the left lateral decubitus position.
bulged each time the baby strained. The clinical impression was of a CSF collection in communication with the subarachnoid space. Recommendations were made to observe the child at home without specific interventions, and to encourage oral fluid intake. The bulge resolved within 48 hours. Six months later, at telephone follow-up, the parents reported that the baby was developing normally Figs. 1 and 2. 3. Discussion Recent concerns about the potential neurotoxicity of general anesthesia has led to a resurgence in popularity of spinal anesthesia and adjunctive regional anesthesia for lower abdominal and extremity surgery in young infants. Possible advantages include decreased exposure to general anesthesia and diminished incidence of postoperative apnea in preterm and former preterm infants [2]. However, there have been no longterm outcome studies of the safety of spinal anesthesia in young infants. In awake, older children, the most common complaints after lumbar puncture are headache and backache. The incidence of these symptoms depends on the series. More than 26% of children undergoing diagnostic lumbar punctures had these symptoms, yet less than 5% of children older than one year have shown these symptoms after spinal anesthesia [3,4]. The effects of postoperative analgesics in the surgical group of patients may be obscuring the true incidence of symptoms referable to CSF leak. Other very rare consequences of CSF leakage after dural puncture in children include paresthesias, weakness, hyporeflexia, and frank cauda equina syndrome leading to emergency surgery [5,6]. The incidence of headache, backache, or other symptoms after spinal anesthesia in the young infant and neonate are unknown. A prospective study using ultrasound to identify the frequency of CSF leak after diagnostic lumbar puncture was concerning [7]. In that study, 21 of 33 neonates had CSF in their epidural space that was documented by ultrasound 24 hours after their dural puncture. The spinal needle used in that study was a 25-G, 25 mm needle with a stylet; the dural punctures were done in neonates with suspected sepsis, meningitis, or seizures. Nine of the infants had spread of their CSF from the cauda equina to the lumbar region, 8 from the cauda
equina to the thoracic region, and 4 from the cauda equina to the cervical region. There was no evidence of respiratory depression or compromise in the 4 patients with cervical CSF epidural spread. In 8 patients, CSF leakage was so extensive that the subarachnoid space was nearly obliterated. Only 5 patients had repeat ultrasounds, which showed that the CSF leakage resolved within 2 to 8 days. There was no difference in CSF leakage in traumatic versus atraumatic lumbar punctures. It is not known whether the risk of ongoing CSF leakage is higher when lumbar puncture is performed for evaluation of acute illness, as in the above series, than when it is performed electively for spinal anesthesia. Despite these radiographic findings, none of the infants showed any transient or persistent clinical signs indicative of neurologic sequelae. Techniques to decrease the incidence of symptoms referable to CSF leakage in adults include using smaller needles, inserting the needle with the bevel oriented parallel to the spine, and stylet reinsertion prior to needle removal [8–10]. The number of attempts at dural puncture is not related to the incidence of symptoms of CSF leakage [7,11]. In young infants who are fasted before their spinal anesthetic, it is sometimes difficult to obtain free-flowing CSF with a small needle. In this patient, two attempts at lumbar puncture were made with a 25-G pediatric needle before the anesthesiologist opted to try with a 22-G spinal needle. Also of note is that placing the patient in the supine position after the lumbar puncture has not been proven to decrease postlumbar puncture symptoms [12]. It is impossible to know whether this fluid originated from a previous lumbar epidural CSF collection or from new CSF leakage from the subdural space that formed when she strained. Her parents reported that she seemed fussier and more irritable after the lumbar mass was noted, leading one to believe that it was a new onset CSF leak. If so, it is very likely that she had concurrent CSF leakage into her epidural space, causing her to experience headache and irritability. The optimal management of this complication is unknown but careful observation and conservative measures such as encouraging adequate oral intake seem prudent, and they worked in this case. This case highlights one of the rare complications of spinal anesthesia in infants. The most common complication of spinal anesthesia in infancy is a failed block, occurring less than 5% of the time or inadequate block necessitating adjunctive general anesthesia or sedation [13]. Although the prevalence of large CSF leaks even extending into the cervical epidural space after dural puncture is quite common in infants, it is also reassuring that several large studies have not shown any significant issues with neurologic or respiratory compromise postoperatively in infants having spinal anesthesia or diagnostic lumbar punctures [13,14].
Fig. 2. View of the 1 × 1.5 cm swelling (arrow) over the L3-L4 interspace, with infant placed upright.
J.I. Allee et al. / Journal of Clinical Anesthesia 25 (2013) 217–219
The importance of ongoing anesthetic registries such as the Pediatric Regional Anesthetic Network (PRAN) in elucidating the incidence of these rare complications is important [15]. As anesthesiologists, we need to be aware of the common occurrence of CSF leakage into the epidural space after spinal anesthesia in infants. Anesthesiologists performing spinal anesthesia in infants should establish systems for follow-up to ensure early detection and intervention for potential sequelae. References [1] Sahin M, Apiliogullari S. Spinal anesthesia is a blessing for children. Paediatr Anaesth 2011;21:908. [2] Welborn LG, Rice LJ, Hannallah RS, Broadman LM, Ruttimann UE, Fink R. Postoperative apnea in former preterm infants: prospective comparison of spinal and general anesthesia. Anesthesiology 1990;72:838–42. [3] Kokki H, Hendolin H, Turunen M. Postdural puncture headache and transient neurologic symptoms in children after spinal anaesthesia using cutting and pencil point paediatric spinal needles. Acta Anaesthesiol Scand 1998;42:1076–82. [4] Ebinger F, Kosel C, Pietz J, Rating D. Headache and backache after lumbar puncture in children and adolescents: a prospective study. Pediatrics 2004;113:1588–92. [5] Amini A, Liu JK, Kan P, Brockmeyer DL. Cerebrospinal fluid dissecting into spinal epidural space after lumbar puncture causing cauda equina syndrome: review of literature and illustrative case. Childs Nerv Syst 2006;22:1639–41.
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[6] Atabaki S, Ochsenschlager D. Post-lumbar puncture headache and backache in pediatrics: a case series and demonstration of magnetic resonance imaging findings. Arch Pediatr Adolesc Med 1999;153:770–3. [7] Kiechl-Kohlendorfer U, Unsinn KM, Schlenck B, Trawöger R, Gassner I. Cerebrospinal fluid leakage after lumbar puncture in neonates: incidence and sonographic appearance. AJR Am J Roentgenol 2003;181:231–4. [8] Tourtellotte WW, Henderson WG, Tucker RP, Gilland O, Walker JE, Kokman E. A randomized, double-blind clinical trial comparing the 22 versus 26 gauge needle in the production of the post-lumbar puncture syndrome in normal individuals. Headache 1972;12:73–8. [9] Richman JM, Joe EM, Cohen SR, et al. Bevel direction and postdural puncture headache: a meta-analysis. Neurologist 2006;12:224–8. [10] Strupp M, Brandt T, Müller A. Incidence of post-lumbar puncture syndrome reduced by reinserting the stylet: a randomized prospective study of 600 patients. J Neurol 1998;245:589–92. [11] Koch BL, Moosbrugger EA, Egelhoff JC. Symptomatic spinal epidural collections after lumbar puncture in children. AJNR Am J Neuroradiol 2007;28:1811–6. [12] Hilton-Jones D, Harrad RA, Gill MW, Warlow CP. Failure of postural manoeuvres to prevent lumbar puncture headache. J Neurol Neurosurg Psychiatry 1982;45: 743–6. [13] Williams 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. [14] Kachko L, Simhi E, Tzeitlin E, et al. Spinal anesthesia in neonates and infants - a single-center experience of 505 cases. Paediatr Anaesth 2007;17:647–53. [15] Polaner DM. Martin LD; PRAN Investigators. Quality assurance and improvement: the Pediatric Regional Anesthesia Network. Paediatr Anaesth 2012;22:115–9.
Contents lists available at SciVerse ScienceDirect
Journal of Clinical Anesthesia journal homepage: www.JCAfulltextonline.com
Case Report
A case of cerebrospinal fluid leak in an infant after spinal anesthesia☆,☆☆ Joy I. Allee MD (Fellow in Anesthesia) a, Kathryn M. Goins MD (Fellow in Anesthesia) a, Charles B. Berde MD, PhD (Professor of Anaesthesia) a, b, Mary Ellen McCann MD, MPH (Associate Professor of Anaesthesia) a, b,⁎ a b
Department of Anesthesiology, Perioperative and Pain Medicine, Children's Hospital Boston, Boston, MA 02115, USA Department of Anaesthesia, Harvard Medical School, Boston, MA 02115, USA
a r t i c l e
i n f o
Article history: Received 4 April 2012 Received in revised form 11 July 2012 Accepted 21 July 2012 Keywords: Anesthesia Pediatric Cerebral spinal fluid Infant Spinal anesthesia: Complication
a b s t r a c t A 2 month old, 51 kg female infant underwent neuraxial anesthesia for repair of a right inguinal hernia. After two unsuccessful attempts at obtaining free-flowing cerebrospinal fluid (CSF) in the L3-L4 lumbar interspace with a 25-gauge (G) neonatal spinal needle, clear CSF was obtained using a Quincke 22-G needle. After easy aspiration, a total of 0.7 mL of 0.75% hyperbaric bupivicaine was injected intrathecally. Immediately after the spinal block, a caudal epidural block was placed by injecting 2 mL of 0.25% bupivacaine with 1:200,000 using a 22-G Quincke spinal needle. Surgery and recovery were uneventful. Two days later, after a crying spell, a bulging, grape size swelling was noted in the infant’s lumbar region. Examination was normal except that her fontanel was mildly depressed when she was upright, and a 1 - 1.5 cm soft, nontender swelling in her lumbar area bulged out when she strained. The bulge resolved over the next 48 hours. In the majority of neonates, CSF leaks into the epidural space after lumbar puncture. In our case, the patient showed CSF accumulation at the site of puncture. © 2013 Elsevier Inc. All rights reserved.
1. Introduction For infants, spinal anesthesia is gaining acceptance as an alternative to general anesthesia [1]. After consultation with our Office of Clinical Investigation and consent by the parents, we report the rare occurrence of subcutaneous cerebrospinal fluid (CSF) accumulation at the puncture site of a 2 month old infant, two days after a spinal anesthetic was performed. 2. Case report A 5.1 kg, former term and otherwise healthy, 2 month old infant girl presented for right inguinal herniorrhaphy and laparascopic exploration of the left side. On discussion of a general versus neuraxial (spinal and caudal) anesthetic technique, the parents agreed on the latter anesthetic option. The infant was brought back to the operating room, standard ASA monitors were applied, and intravenous access was established. The infant was positioned sitting for placement of the spinal anesthetic. After a sterile prep and drape, a 25-gauge (G), 2.54 ☆ None of the authors has any financial relationships related to this publication. ☆☆ Presented in part at the Winter Meeting of the Society for Pediatric Anesthesia/ American Academy of Pediatrics (SPA/AAP), Tampa, FL, Feb. 23-26, 2012. ⁎ Correspondence: Mary Ellen McCann, MD, MPH, Department of Anesthesiology, Perioperative and Pain Medicine, Children’s Hospital Boston, 300 Longwood Ave., Boston, MA 02115, USA. Tel.: +1 617 355 7737. E-mail address: [email protected] (M.E. McCann). 0952-8180/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jclinane.2012.07.008
cm neonatal spinal needle was introduced at the L3-L4 lumbar interspace. Two atraumatic passes were attempted without freeflowing CSF. At this time, since the infant was agitated, it was decided to reattempt at the same level using a 22-G, 3.8 cm pediatric Quincke spinal needle. On the first attempt, there was free-flowing, clear, nonbloody CSF. After easy aspiration, a total of 0.7 mL of 0.75% hyperbaric bupivicaine was injected intrathecally. The procedure was uncomplicated; the infant was placed first in reverse Trendelenburg position, then positioned in right lateral decubitus for the caudal anesthetic. A 22-G Quincke spinal needle was used to find the caudal epidural space with negative aspiration of CSF and blood. A total of 2 mL of bupivicaine 2.5 mg/mL solution with epinephrine 5 μg/mL was easily injected incrementally with no evidence of electrocardiographic (ECG) changes. The surgical procedure was completed without incident, and the patient went home later that day with no concerns. Two days later, after the infant’s crying spell, her parents noted a bulging, grape-sized subcutaneous swelling in the patient’s back, in the area of the spinal needle entry site. The bulge increased in size each time the infant cried. The skin over the site appeared intact. She was also more irritable when being held upright. There was no evidence of fevers, erythema, or discharge at the site. The patient was brought to the emergency department for evaluation. She was noted to be a happy, well-appearing infant with a nonfocal neurological examination. Her fontanel was mildly depressed when upright, but flat when she was lying supine. A 1 to 1.5 cm soft, nontender, nonerythematous swelling was noted in the lumbar area, which
218
J.I. Allee et al. / Journal of Clinical Anesthesia 25 (2013) 217–219
Fig. 1. View of the 1 × 1.5 cm swelling (arrow) over the L3-L4 interspace, with infant in the left lateral decubitus position.
bulged each time the baby strained. The clinical impression was of a CSF collection in communication with the subarachnoid space. Recommendations were made to observe the child at home without specific interventions, and to encourage oral fluid intake. The bulge resolved within 48 hours. Six months later, at telephone follow-up, the parents reported that the baby was developing normally Figs. 1 and 2. 3. Discussion Recent concerns about the potential neurotoxicity of general anesthesia has led to a resurgence in popularity of spinal anesthesia and adjunctive regional anesthesia for lower abdominal and extremity surgery in young infants. Possible advantages include decreased exposure to general anesthesia and diminished incidence of postoperative apnea in preterm and former preterm infants [2]. However, there have been no longterm outcome studies of the safety of spinal anesthesia in young infants. In awake, older children, the most common complaints after lumbar puncture are headache and backache. The incidence of these symptoms depends on the series. More than 26% of children undergoing diagnostic lumbar punctures had these symptoms, yet less than 5% of children older than one year have shown these symptoms after spinal anesthesia [3,4]. The effects of postoperative analgesics in the surgical group of patients may be obscuring the true incidence of symptoms referable to CSF leak. Other very rare consequences of CSF leakage after dural puncture in children include paresthesias, weakness, hyporeflexia, and frank cauda equina syndrome leading to emergency surgery [5,6]. The incidence of headache, backache, or other symptoms after spinal anesthesia in the young infant and neonate are unknown. A prospective study using ultrasound to identify the frequency of CSF leak after diagnostic lumbar puncture was concerning [7]. In that study, 21 of 33 neonates had CSF in their epidural space that was documented by ultrasound 24 hours after their dural puncture. The spinal needle used in that study was a 25-G, 25 mm needle with a stylet; the dural punctures were done in neonates with suspected sepsis, meningitis, or seizures. Nine of the infants had spread of their CSF from the cauda equina to the lumbar region, 8 from the cauda
equina to the thoracic region, and 4 from the cauda equina to the cervical region. There was no evidence of respiratory depression or compromise in the 4 patients with cervical CSF epidural spread. In 8 patients, CSF leakage was so extensive that the subarachnoid space was nearly obliterated. Only 5 patients had repeat ultrasounds, which showed that the CSF leakage resolved within 2 to 8 days. There was no difference in CSF leakage in traumatic versus atraumatic lumbar punctures. It is not known whether the risk of ongoing CSF leakage is higher when lumbar puncture is performed for evaluation of acute illness, as in the above series, than when it is performed electively for spinal anesthesia. Despite these radiographic findings, none of the infants showed any transient or persistent clinical signs indicative of neurologic sequelae. Techniques to decrease the incidence of symptoms referable to CSF leakage in adults include using smaller needles, inserting the needle with the bevel oriented parallel to the spine, and stylet reinsertion prior to needle removal [8–10]. The number of attempts at dural puncture is not related to the incidence of symptoms of CSF leakage [7,11]. In young infants who are fasted before their spinal anesthetic, it is sometimes difficult to obtain free-flowing CSF with a small needle. In this patient, two attempts at lumbar puncture were made with a 25-G pediatric needle before the anesthesiologist opted to try with a 22-G spinal needle. Also of note is that placing the patient in the supine position after the lumbar puncture has not been proven to decrease postlumbar puncture symptoms [12]. It is impossible to know whether this fluid originated from a previous lumbar epidural CSF collection or from new CSF leakage from the subdural space that formed when she strained. Her parents reported that she seemed fussier and more irritable after the lumbar mass was noted, leading one to believe that it was a new onset CSF leak. If so, it is very likely that she had concurrent CSF leakage into her epidural space, causing her to experience headache and irritability. The optimal management of this complication is unknown but careful observation and conservative measures such as encouraging adequate oral intake seem prudent, and they worked in this case. This case highlights one of the rare complications of spinal anesthesia in infants. The most common complication of spinal anesthesia in infancy is a failed block, occurring less than 5% of the time or inadequate block necessitating adjunctive general anesthesia or sedation [13]. Although the prevalence of large CSF leaks even extending into the cervical epidural space after dural puncture is quite common in infants, it is also reassuring that several large studies have not shown any significant issues with neurologic or respiratory compromise postoperatively in infants having spinal anesthesia or diagnostic lumbar punctures [13,14].
Fig. 2. View of the 1 × 1.5 cm swelling (arrow) over the L3-L4 interspace, with infant placed upright.
J.I. Allee et al. / Journal of Clinical Anesthesia 25 (2013) 217–219
The importance of ongoing anesthetic registries such as the Pediatric Regional Anesthetic Network (PRAN) in elucidating the incidence of these rare complications is important [15]. As anesthesiologists, we need to be aware of the common occurrence of CSF leakage into the epidural space after spinal anesthesia in infants. Anesthesiologists performing spinal anesthesia in infants should establish systems for follow-up to ensure early detection and intervention for potential sequelae. References [1] Sahin M, Apiliogullari S. Spinal anesthesia is a blessing for children. Paediatr Anaesth 2011;21:908. [2] Welborn LG, Rice LJ, Hannallah RS, Broadman LM, Ruttimann UE, Fink R. Postoperative apnea in former preterm infants: prospective comparison of spinal and general anesthesia. Anesthesiology 1990;72:838–42. [3] Kokki H, Hendolin H, Turunen M. Postdural puncture headache and transient neurologic symptoms in children after spinal anaesthesia using cutting and pencil point paediatric spinal needles. Acta Anaesthesiol Scand 1998;42:1076–82. [4] Ebinger F, Kosel C, Pietz J, Rating D. Headache and backache after lumbar puncture in children and adolescents: a prospective study. Pediatrics 2004;113:1588–92. [5] Amini A, Liu JK, Kan P, Brockmeyer DL. Cerebrospinal fluid dissecting into spinal epidural space after lumbar puncture causing cauda equina syndrome: review of literature and illustrative case. Childs Nerv Syst 2006;22:1639–41.
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[6] Atabaki S, Ochsenschlager D. Post-lumbar puncture headache and backache in pediatrics: a case series and demonstration of magnetic resonance imaging findings. Arch Pediatr Adolesc Med 1999;153:770–3. [7] Kiechl-Kohlendorfer U, Unsinn KM, Schlenck B, Trawöger R, Gassner I. Cerebrospinal fluid leakage after lumbar puncture in neonates: incidence and sonographic appearance. AJR Am J Roentgenol 2003;181:231–4. [8] Tourtellotte WW, Henderson WG, Tucker RP, Gilland O, Walker JE, Kokman E. A randomized, double-blind clinical trial comparing the 22 versus 26 gauge needle in the production of the post-lumbar puncture syndrome in normal individuals. Headache 1972;12:73–8. [9] Richman JM, Joe EM, Cohen SR, et al. Bevel direction and postdural puncture headache: a meta-analysis. Neurologist 2006;12:224–8. [10] Strupp M, Brandt T, Müller A. Incidence of post-lumbar puncture syndrome reduced by reinserting the stylet: a randomized prospective study of 600 patients. J Neurol 1998;245:589–92. [11] Koch BL, Moosbrugger EA, Egelhoff JC. Symptomatic spinal epidural collections after lumbar puncture in children. AJNR Am J Neuroradiol 2007;28:1811–6. [12] Hilton-Jones D, Harrad RA, Gill MW, Warlow CP. Failure of postural manoeuvres to prevent lumbar puncture headache. J Neurol Neurosurg Psychiatry 1982;45: 743–6. [13] Williams 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. [14] Kachko L, Simhi E, Tzeitlin E, et al. Spinal anesthesia in neonates and infants - a single-center experience of 505 cases. Paediatr Anaesth 2007;17:647–53. [15] Polaner DM. Martin LD; PRAN Investigators. Quality assurance and improvement: the Pediatric Regional Anesthesia Network. Paediatr Anaesth 2012;22:115–9.