Thierry Pirotte

Living Donor Liver Transplantation in Children: Surgical and Immunological Results in 250 Recipients at Université Catholique de Louvain.

Objectives: To evaluate the outcome of pediatric living donor liver transplantation (LDLT) regarding portal vein (PV) reconstruction, ABO compatibility, and impact of maternal donation on graft acceptance. Background: LDLT and ABO-mismatched transplantation constitute feasible options to alleviate organ shortage in children. Vascular complications of portal hypoplasia in biliary atresia (BA) and acute rejection (AR) are still major concerns in this field. Methods: Data from 250 pediatric LDLT recipients, performed at Cliniques Universitaires Saint-Luc between July 1993 and June 2012, were collected retrospectively. Results were analyzed according to ABO matching and PV complications. Uni- and multivariate analyses were performed to study the impact of immunosuppression, sex matching, and maternal donation on AR rate. Results: Overall, the 10-year patient survival rate was 93.2%. Neither patient or graft loss nor vascular rejection, nor hemolysis, was encountered in the ABO nonidentical patients (n = 58), provided pretransplant levels of relevant isoagglutinins were below 1/16. In BA recipients, the rate of PV complications was lower after portoplasty (4.6%) than after truncal PV anastomosis (9.8%) and to jump graft interposition (26.9%; P = 0.027). In parental donation, maternal grafts were associated with higher 1-year AR-free survival (55.2%) than paternal grafts (39.8%; P = 0.041), but only in BA patients. Conclusions: LDLT, including ABO-mismatched transplantation, constitutes a safe and efficient therapy for liver failure in children. In BA patients with PV hypoplasia, portoplasty seems to constitute the best technique for PV reconstruction. Maternal donation might be a protective factor for AR.

Ultrasound-guided proximal and distal sciatic nerve blocks in children.

STUDY OBJECTIVE To present the use of ultrasonography for the performance of proximal subgluteal and distal sciatic nerve blocks in children. DESIGN Prospective descriptive study. SETTING University hospital. PATIENTS 45 ASA physical status I, II, and III patients, aged between 8 months and 16 years, scheduled for lower limb surgery. INTERVENTIONS During general anesthesia, proximal, subgluteal, and distal sciatic nerve blocks using ultrasonography were performed. If severe postoperative pain was expected, a catheter technique was used. MEASUREMENTS The injected amount of local anesthetic was noted. Based on the spread of local anesthetic, prediction for successful block was made. Complications, adverse effects, postoperative pain scores, and parent satisfaction scores were noted. MAIN RESULTS 21 proximal sciatic nerve blocks (12 single-injection and 9 continuous blocks) and 35 distal sciatic nerve blocks (17 single-injection, 6 bilateral single-injection, 4 continuous, and one bilateral continuous block) were performed. A mean initial dose of 0.25 mL.kg(-1) of ropivacaine 0.375% was injected. A successful block was obtained in all children. Excellent postoperative pain relief was obtained. All parents were satisfied with the postoperative pain relief. No complications occurred. CONCLUSION Ultrasonography is useful in the identification of the sciatic nerve and it facilitates needle and catheter placement for proximal and distal nerve blocks in children.

Postoperative apnea in a former preterm infant: Clonidine or too much unbound bupivacaine?

To the Editor: We read with great interest the report of 2 episodes of early postoperative apnea in a 39-week-old former preterm infant who had received 5 mg/kg lidocaine 2.5 mg/kg bupivacaine and 1.25 g/kg clonidine caudally to undergo awake inguinal hernia repair.1 The authors point to clonidine as the most likely cause of (central?) apnea approximately 35 minutes after the caudal injection. However, we would like to highlight some pharmacological aspects that were only alluded to in the Discussion and which should be kept in mind when using bupivacaine in neonates and small infants. First, in 13 infants receiving 2.5 mg/kg bupivacaine caudally, the peak plasma (venous) concentration of bupivacaine was measured from 10 to 60 minutes after the injection (mean and SD: 28 and 13 minutes).2 At that age, because of diminished plasma protein binding, a single epidural bolus injection of bupivacaine results in an increased free fraction of bupivacaine, but not necessarily in an increased unbound plasma concentration because of its increased volume of distribution.3 However, the maximum concentration of unbound bupivacaine measured varied from 0.05 to 0.21 g/mL, and 2 of those 13 infants (15%) had unbound plasma bupivacaine levels greater than 0.2 g/mL, which is often considered as the threshold for central nervous system (CNS) toxicity in awake adults.2 Second, bupivacaine, like any amide local anesthetic, binds mainly to 1-acid glycoprotein (AAG): this is a highaffinity but saturable process and the serum concentration of AAG is low in healthy infants less than 2 to 3 months old with no inflammatory process.2,3 We therefore wonder whether injecting the maximal recommended dose of bupivacaine concomitantly with lidocaine does not lead to competition for binding to AAG: even if bupivacaine is less protein-bound in infants, a small decrease in protein binding can produce an important increase in its unbound concentration.4 In the case reported, the blood concentration of unbound bupivacaine and/or lidocaine could thus have been high at the time of apnea. Third, Breschan et al.5 observed a decrease in alertness and in upper extremity muscle tone as well as a decreased frequency in electroencephalogram recording in 6 of 7 awake infants 20 minutes after the caudal injection of 3.1 mg/kg bupivacaine with epinephrine 5 g/mL. The total bupivacaine level measured at the same time varied from 0.56 to 1.62 g/mL; unfortunately, unbound bupivacaine was not measured nor was the upper level of sensory block obtained assessed. Although these side effects could be attributed to diminished sensory input to the brain, as shown for spinal anesthesia in adults,6 rather than to direct CNS toxicity of unbound bupivacaine, these authors recommend using no more than 2 mg/kg bupivacaine caudally in small infants. On the other hand, the pharmacology of epidural clonidine in infancy is unknown. In children ages 1 to 9 years, its systemic absorption shows considerable interindividual variation: the venous Cmax obtained after the (lumbar) epidural injection of 2 g/kg varies from 0.45 to 0.77 ng/mL and occurs 48 to 193 minutes after the injection.7 In adults, the rate of diffusion of epidural clonidine across the dura is rapid and extensive8: peak cerebrospinal fluid concentrations are observed 31 4 minutes after the epidural injection, but no data are available in pediatric patients. In conclusion, although clonidine cannot be excluded as a possible cause of early postoperative apnea, we hypothetize that in the case reported, high levels of unbound bupivacaine and/or lidocaine were present at the time of apnea because a high dose of bupivacaine was administered with lidocaine to an infant with physiologically low levels of AAG. This could be another cause of or contributing factor to the early apneic episodes observed.

Nasal foreign bodies in children: a possible pitfall for the anesthesiologist.

Based on a recent surprising case in our institution, we analyze the possible dislodgment of an unknown foreign body in the nose during nasotracheal intubation in children. Nasal foreign bodies made of inert material can remain unnoticed for a long period of time. In addition to inserting a close‐fitting suction catheter into the TT during its passage through the nasopharynx, we now suggest performing a pharyngoscopy when intubation is completed.

Bloc caudal associé à une anesthésie au masque facial (Sévoflurane) chez le nourrisson à haut risque d'apnée : étude observationnelle

OBJECTIVE In order to reduce the risk of postoperative apnoea, awake spinal anaesthesia or awake caudal anaesthesia are recommended for hernia surgery in newborn babies and former premature infants aged less than 60 weeks of amenorrhoea. However, additional sedation is sometimes necessary. Our working hypothesis was that a general anaesthesia with a face mask (sevoflurane) with no opiates nor neuromuscular blocking agents, maintaining the infants spontaneous breathing and combined with a caudal anaesthesia, could provide a safe and effective alternative. STUDY DESIGN The epidemiological and technical data about the patient and the anaesthesia, as well as any per- and postoperative complications, were collected prospectively and analysed retrospectively. PATIENTS AND METHODS Ninety-eight infants undergoing hernia surgery were included during the period from 2003 to 2008. RESULTS Caudal anaesthesia proved successful at first attempt in 69% of the infants (term or premature). Three attempts were needed in 8% of the infants born at term and 2% of the infants born prematurely. One failure was recorded. Seven patients presented one episode of peroperative apnoea; they were easily taken care of by means of brief face mask ventilation. The follow-up of these seven infants did not reveal any reappearance of postoperative apnoea/bradypnoea. CONCLUSION The technique proposed is an effective alternative to the awake locoregional anaesthesia techniques: it provides excellent conditions for surgery and presents similar perioperative morbidity and risk of postoperative apnoea.

Liver and systemic hemodynamics in children with cirrhosis: Impact on the surgical management in pediatric living donor liver transplantation.

Cirrhosis in adults is associated with modifications of systemic and liver hemodynamics, whereas little is known about the pediatric population. The aim of this work was to investigate whether alterations of hepatic and systemic hemodynamics were correlated with cirrhosis severity in children. The impact of hemodynamic findings on surgical management in pediatric living donor liver transplantation (LT) was evaluated. Liver and systemic hemodynamics were studied prospectively in 52 children (median age, 1 year; 33 with biliary atresia [BA]). The hemodynamics of native liver were studied preoperatively by Doppler ultrasound and intraoperatively using invasive flowmetry. Portosystemic gradient was invasively measured. Systemic hemodynamics were studied preoperatively by Doppler transthoracic echocardiography and intraoperatively by using transpulmonary thermodilution. Hemodynamic parameters were correlated with Pediatric End‐Stage Liver Disease (PELD) score and the histological degree of fibrosis (collagen proportionate area [CPA]). Cirrhosis was associated with a 60% reduction of pretransplant total liver flow (n = 46; median, 36 mL/minute/100 g of liver) compared with noncirrhotic livers (n = 6; median, 86 mL/minute/100 g; P = 0.002). Total blood flow into the native liver was negatively correlated with PELD (P < 0.001) and liver CPA (P = 0.005). Median portosystemic gradient was 14.5 mm Hg in children with cirrhosis and positively correlated with PELD (P < 0.001). Portal vein (PV) hypoplasia was observed mainly in children with BA (P = 0.02). Systemic hemodynamics were not altered in our children with cirrhosis. Twenty‐one children met the intraoperative criteria for PV reconstruction using a portoplasty technique during the LT procedure and had a smaller PV diameter at pretransplant Doppler ultrasound (median = 3.4 mm; P < 0.001). Cirrhosis in children appears also as a hemodynamic disease of the liver, correlated with cirrhosis severity. Surgical technique for PV reconstruction during LT was adapted accordingly. Liver Transplantation 23 1440–1450 2017 AASLD.

Vascular Access in the Perioperative Period

Vascular access is of major importance in the perioperative period. Anesthesiologist and pediatricians, as experts, should master their techniques and have a thorough knowledge of the existing tools that could assist difficult vascular accesses.

Cricoid pressure can be useful

AB has acted as a paid consultant to Laryngeal Mask Airway Group, Germany, and 3M Deutschland GmbH, Germany, and received a fee for speaking from Medisize Corporation, Germany. LW and RS have no conflict of interests to declare. Lars Witt, Robert S€ umpelmann, Anselm Br€auer Department of Anaesthesiology and Intensive Care Medicine, Hanover Medical School, Hanover, Germany Department of Anaesthesiology, Emergency and Intensive Care Medicine, University Medical Centre Göttingen, Göttingen, Germany Email: witt.lars-henrik@mh-hannover.de