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Objective: Identification of at risk patients before surgery could facilitate improved clinical communication, care pathways and postoperative pain management., Design: A retrospective cohort study was performed in all infants who had undergone cleft palate repair., Setting: Tertiary Institutional., Participants: Infants < 36 months of age who underwent primary repair of cleft palate between March 2016 and July 2022., Intervention: Requirement for analgesic intervention in the post operative care unit., Main Outcome Measure: Adverse perioperative event defined as pain or distress. Secondary outcomes were the incidence of airway obstruction, hypoxemia or unplanned intensive care admission., Results: Two hundred and ninety one patients (14.6 months,10.1 kg weight) were included. Cleft distribution included submucous (5.2%), Veau I (23.4%), Veau 2 (38.1%), Veau 3 (24.4%), and Veau 4 (8.9%). Overall 35% of 291 infants undergoing cleft palate repair experienced pain or distress requiring opiate intervention in the first hour after surgery. Infants with a Veau 4 cleft palate had 1.8 times and Veau 2 cleft palate had 1.5 times the risk of postoperative pain compared to infants with Veau 1 cleft palate (relative risk 1.82, 95%CI 1.04-3.18 and 1.49, 95%CI 0.96-2.32 respectively). The use of bilateral above elbow arm splints was significantly associated with postoperative pain or distress (odds ratio 2.23, 95%CI 1.01-5.16)., Conclusions: Post operative pain requiring intervention in PACU is common despite adequate intraoperative multimodal analgesia, local anaesthesia infiltration and postoperative opiate infusions. Infants undergoing soft palate alone or submucous palate repair may require less perioperative opiates., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Introduction: Infant spinal anesthesia is an important technique in premature and ex-premature infants undergoing lower abdominal surgery. Previous studies of infant spinal anesthesia report high failure rates, but fail to adequately identify contributing factors. The aim of this study is to retrospectively review spinal anesthetics from a quaternary anesthetic centre to determine overall spinal failure rate, incidence of second spinal attempts and adverse events associated with a second spinal anesthetic., Methods: A retrospective review of infant spinal anesthetics performed between May 2016 and June 2023., Results: Five hundred and fifty-one infants (mean postmenstrual age 42.9 weeks and weight 3873 g) were included. The overall success rate on first attempt was 86.5% with a further 5.1% requiring a successful second spinal anesthetic after initial failure. Spinal anesthetic failure requiring conversion to general anesthesia occurred in 9.4% of cases The causes of failed spinal anesthetic were inability to access the subdural space (dry tap 4.2%), inadequate motor blockade (2.9%), and repeated bloody taps (2.2%). Spinal anesthetic failure was significantly increased in cases where the anesthetist was routinely performing less than 5 spinal anesthetics per year [OR 2.21 (95% CI 1.28, 3.83, p = .004)] but only weakly associated with years of pediatric anesthetic experience. Failure rates were 21.4% with styletted spinal needles and 9.2% for non styletted [OR 2.68 (95% CI 1.23-5.86, p = .012)]. The incidence of perioperative apnoea was 6.7% with the highest rate in infants in which failed spinal anesthesia required conversion to general anesthesia (25%). There were 28 cases where initial spinal anesthetic failed to produce adequate anesthesia and a repeat spinal anesthetic was performed. Repeat spinal anesthesia was successful in 92.8% of cases with awake caudal anesthesia successful in 7.2% of cases. In three cases high spinal blockade occurred, one after a single spinal and two after a repeat spinal. Both repeat spinal high block cases required intubation and brief resuscitation., Conclusion: Infant spinal anesthesia is associated with high success rates if experienced anesthetists are present or performing the block. Repeat spinal anesthesia may be associated with an increased incidence of high spinal block. Greater awareness of the slow onset of high block should promote techniques aimed at minimizing cephalad spread of local anesthetic including slight head up positioning during surgery., (© 2023 The Authors. Pediatric Anesthesia published by John Wiley & Sons Ltd.)

Aim: A single caudal anesthetic at the start of lower abdominal surgery is unlikely to provide prolonged analgesia. A second caudal at the end of the procedure extends the analgesia duration but total plasma concentrations may be associated with toxicity. Our aim was to measure total plasma levobupivacaine concentrations after repeat caudal anesthesia in infants and to generate a pharmacokinetic model for prediction of plasma concentrations after repeat caudal anesthesia in neonates, infants and children., Methods: Infants undergoing definitive repair of anorectal malformations or Hirschsprung's disease received a second caudal anesthesia at the end of the procedure. Total levobupivacaine concentrations were assayed 3-4 times in the first 6 h after the initial caudal. These data were pooled with data from four studies describing plasma concentrations after levobupivacaine caudal or spinal anesthesia. Population pharmacokinetic parameters were estimated using nonlinear mixed-effects models. Covariates included postmenstrual age and body weight. Parameter estimates were used to simulate concentrations after a repeat levobupivacaine 2.5 mg kg -1 caudal at 3 or 4 h following an initial levobupivacaine 2.5 mg kg -1 caudal., Results: Twenty-one infants (postnatal age 11-32 weeks, gestation 37-39 weeks, weight 5.2-8.6 kg) were included. The measured peak plasma concentration after repeat caudal levobupivacaine 2.5 mg kg -1 4 h after initial caudal was 1.38 mg L -1 (95% prediction interval 0.60-2.6 mg L -1 ) and 3 h after initial caudal was 1.46 mg L -1 (0.60-2.80) mg L -1 . Simulation of total plasma concentrations in neonates (7 kg, 57 weeks postmenstrual age) given caudal levobupivacaine 4 h after the initial caudal were 1.76 mg L -1 (0.68-3.50) mg L -1 if 2.5 mg kg -1 levobupivacaine was used and 0.88 mg L -1 (0.34-1.73) mg L -1 if 1.25 mg kg -1 of 0.125% levobupivacaine was used. In simulated older children (20 kg, 6 years), the mean maximum concentration was 1.43 mg L -1 (0.60-2.70) mg L -1 if 2.5 mg kg -1 levobupivacaine was repeated at 3 h., Conclusion: Repeat caudal levobupivacaine 2.5 mg kg -1 at 3 h after an initial 2.5 mg kg -1 dose does not exceed the concentration associated with systemic local anesthetic toxicity. In 2.5% of simulated neonates (weight 3.8 kg, PMA 40 weeks), repeat caudal anesthesia demonstrates broaching of the lower concentration limit associated with toxicity at both 3 and 4 h after initial caudal., (© 2022 John Wiley & Sons Ltd.)

Aim: While the proportion of pediatric anesthetics with regional anesthesia in pediatric patients has steadily increased, there are only a few series that describe the use of lower limb peripheral nerve blocks in children. Our aim was to describe the indications, anesthetic approach, and complications associated with lower limb blocks in children undergoing orthopedic surgery in a center with a large caseload of complex patients., Methods: In a retrospective analysis of prospectively collected data, we reviewed children who had a peripheral nerve block for orthopedic surgery placed between January 2016 and January 2021 at the Royal Children's Hospital Melbourne. Block data were sourced from the electronic medical record and departmental regional anesthesia database. Data collected included demographics, the site of catheter placement and technique of nerve block, presence of sensory/motor blockade, the use of perioperative opioids, and any complications related to peripheral nerve block., Results: A total of 1438 blocks were performed in 1058 patients. Four patients had clinical features of perioperative neurological injury giving an incidence of 3 per 1000 blocks (95% CI 1.1-8:1000). Only one patient had a sensory deficit persisting longer than 6 months for an incidence of 0.8 per 1000 blocks (95% CI 0.1-5:1000). All four peripheral nerve injury followed tibial osteotomy for lengthening procedures or correction of tibial torsion. The etiology of the injury could not be determined despite imaging and surgical exploration and the contribution of popliteal sciatic nerve block to the subsequent PNI could not be confirmed. There were no cases of local anesthetic systemic toxicity., Conclusion: An increased risk of perioperative peripheral nerve injury is associated with pediatric tibial osteotomy for congenital deformity. While popliteal sciatic nerve block was not directly implicated in the nerve injury the presence of a prolonged sensory block can delay early recognition and treatment of peripheral nerve injury., (© 2022 John Wiley & Sons Ltd.)

Aim: Pharmacokinetic simulation was used to characterize levobupivacaine disposition after regional anesthetic rescue for failed spinal anesthesia in neonates and infants., Methods: Population pharmacokinetics of levobupivacaine were estimated after spinal blockade in a cohort of neonates and infants (n = 25, postnatal age 5-18 weeks, gestation 21-41 weeks, weight 2.4-6 kg). Total levobupivacaine concentrations were assayed 3-4 times in the first hour after spinal levobupivacaine 1 mg kg -1 administration. Parameters were estimated using nonlinear mixed-effects models and supported by priors. Covariates included postnatal age and total body weight. Parameter estimates were used to simulate total levobupivacaine concentrations after a primary spinal levobupivacaine 1 mg kg -1 with rescue caudal levobupivacaine 1.5-2.5 mg kg -1 ., Results: A one-compartment model with a mature clearance 21.5 L h -1  70 kg -1 (CV 47.3%) and central volume 189 L 70 kg -1 (CV 37%) adequately described time-concentration profiles. Clearance maturation was described using a maturation half-time of 11.5 weeks postnatal age. The absorption half-time for spinal levobupivacaine was 2.6 min (CV 56.8%). The upper (97.5% prediction) for peak concentrations after rescue caudal levobupivacaine were 1.5 mg kg -1 , 2 mg kg -1 , and 2.5 mg kg -1 was 2.05 mg L -1 , 2.5 mg L -1 , and 2.9 mg L -1 respectively., Conclusion: Total bupivacaine concentrations greater than 2.5 mg L -1 are associated with neurotoxicity in adults. Predicted concentrations after either a repeat spinal or a caudal rescue dose of levobupivacaine 1.5 mg kg -1 1 h after spinal levobupivacaine administration are below the neurotoxic concentration threshold., (© 2021 John Wiley & Sons Ltd.)

Aims: The aim of this study was to report the incidence of perioperative adverse events occurring in infants undergoing diode laser photocoagulation of retinopathy of prematurity and to identify clinical risk factors that may affect the incidence., Methods: This was a retrospective study of anesthetic and medical records of premature infants who were treated in the neonatal intensive care unit or an operating theater with laser photocoagulation in our institution between January 2014 and December 2019. Infants less than 38 weeks post-menstrual age or less than 2000 grams were considered high risk for complications. Electronic medical records were evaluated for clinical and demographic characteristics, comorbidities, and perioperative complications of anesthesia., Results: Sixty-one infants (39 males, 22 females) underwent 72 laser treatments. The mean gestational age was 25.3 weeks (SD 1.6), and mean birth weight was 730 grams (SD 202). At treatment, the mean postmenstrual age was 37.5 weeks (SD 2.7) and weight was 2320 g (SD 610). Laser therapy was performed in an operating theater in 66 procedures (91.7%) and in the neonatal unit in 6 cases (8.3%). Twenty-nine (40.3%) laser surgeries occurred outside normal week-day daytime operating hours. Intraoperative hypotension occurred in 12 procedures (16.7%) but was not significantly different in high-risk infants (16.1% vs 16.7% OR 0.94 P = .94) or in procedures performed in-hours (16.3% vs 17.2% OR 0.93 P = .91). Post-extubation apnea occurred in 21 procedures (29%) but was not significantly different in high-risk infants (29.0% vs 27.3% OR 0.98 P = .34) or in procedures performed in-hours (27.9% vs 31.1% OR 0.86 P = .77). Infants remained intubated at the end of the procedure in 58 (80.5%) cases and 29 (40.3%) remained ventilated more than 24 hours after the procedure., Conclusion: The incidence of perioperative adverse events was not associated with patient's age, current weight, timing, or location of the procedure. Extubating infants at the end of the procedure is however associated with a high rate of apneas and bradycardia, and consideration should be given to keeping low weight infants undergoing prolonged procedures out-of-hours intubated., (© 2020 John Wiley & Sons Ltd.)

Purpose of Review: A number of high profile conjoined twin separations have been extensively covered by the world media. Anaesthesia for conjoined twins is a procedure rarely experienced by paediatric anaesthetists. The increased survival of the twins has prompted discussion as to the most appropriate selection of patients, teams and hospitals to provide exceptional anaesthetic care., Recent Findings: The number of conjoined twins presenting for surgery remains low with many infants not surviving foetal or early neonatal life. Anaesthetic management of less common conjoined infants such as craniopagus twins has highlighted the benefit of careful patient selection, extensive preoperative investigations and meticulous multidisciplinary team planning. The role of simulation of possible adverse perioperative events has been highlighted. Three dimensional anatomical models and virtual reality systems have permitted surgical planning in advance of actual intervention. A number of legal and ethical concerns have been reported especially in the setting of emergency separation where surgery is likely to contribute to death of one of the twins., Summary: There appears to be an expanding role for international teams with extensive separation experience becoming involved in international teleconferencing to improve patient management in low-resource countries. Whether the perioperative outcome is better when the conjoined twins are transferred to major centres for surgery or teams operate in the twin's country of origin remains to be seen.

Background: In laboratory animals, exposure to most general anaesthetics leads to neurotoxicity manifested by neuronal cell death and abnormal behaviour and cognition. Some large human cohort studies have shown an association between general anaesthesia at a young age and subsequent neurodevelopmental deficits, but these studies are prone to bias. Others have found no evidence for an association. We aimed to establish whether general anaesthesia in early infancy affects neurodevelopmental outcomes., Methods: In this international, assessor-masked, equivalence, randomised, controlled trial conducted at 28 hospitals in Australia, Italy, the USA, the UK, Canada, the Netherlands, and New Zealand, we recruited infants of less than 60 weeks' postmenstrual age who were born at more than 26 weeks' gestation and were undergoing inguinal herniorrhaphy, without previous exposure to general anaesthesia or risk factors for neurological injury. Patients were randomly assigned (1:1) by use of a web-based randomisation service to receive either awake-regional anaesthetic or sevoflurane-based general anaesthetic. Anaesthetists were aware of group allocation, but individuals administering the neurodevelopmental assessments were not. Parents were informed of their infants group allocation upon request, but were told to mask this information from assessors. The primary outcome measure was full-scale intelligence quotient (FSIQ) on the Wechsler Preschool and Primary Scale of Intelligence, third edition (WPPSI-III), at 5 years of age. The primary analysis was done on a per-protocol basis, adjusted for gestational age at birth and country, with multiple imputation used to account for missing data. An intention-to-treat analysis was also done. A difference in means of 5 points was predefined as the clinical equivalence margin. This completed trial is registered with ANZCTR, number ACTRN12606000441516, and ClinicalTrials.gov, number NCT00756600., Findings: Between Feb 9, 2007, and Jan 31, 2013, 4023 infants were screened and 722 were randomly allocated: 363 (50%) to the awake-regional anaesthesia group and 359 (50%) to the general anaesthesia group. There were 74 protocol violations in the awake-regional anaesthesia group and two in the general anaesthesia group. Primary outcome data for the per-protocol analysis were obtained from 205 children in the awake-regional anaesthesia group and 242 in the general anaesthesia group. The median duration of general anaesthesia was 54 min (IQR 41-70). The mean FSIQ score was 99·08 (SD 18·35) in the awake-regional anaesthesia group and 98·97 (19·66) in the general anaesthesia group, with a difference in means (awake-regional anaesthesia minus general anaesthesia) of 0·23 (95% CI -2·59 to 3·06), providing strong evidence of equivalence. The results of the intention-to-treat analysis were similar to those of the per-protocol analysis., Interpretation: Slightly less than 1 h of general anaesthesia in early infancy does not alter neurodevelopmental outcome at age 5 years compared with awake-regional anaesthesia in a predominantly male study population., Funding: US National Institutes of Health, US Food and Drug Administration, Thrasher Research Fund, Australian National Health and Medical Research Council, Health Technologies Assessment-National Institute for Health Research (UK), Australian and New Zealand College of Anaesthetists, Murdoch Children's Research Institute, Canadian Institutes of Health Research, Canadian Anesthesiologists Society, Pfizer Canada, Italian Ministry of Health, Fonds NutsOhra, UK Clinical Research Network, Perth Children's Hospital Foundation, the Stan Perron Charitable Trust, and the Callahan Estate., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: The GAS study is an international RCT to evaluate neurodevelopmental outcome comparing general plus regional anesthesia versus regional anesthesia alone in 722 neonates and infants who had inguinal hernia repair up to 60 weeks of postmenstrual age. This paper comprises a secondary descriptive analysis of hernias, aspects of surgery and outcomes., Methods: The incidence of unilateral and bilateral hernias, side preponderance, predictive factors for bilateral hernias and surgical approaches were collated. Follow-up outcome data were examined at 2 years., Results: Of 711 eligible patients, there were 679 with hernia data showing that 321 hernias were right-sided, 190 left and 168 bilateral. Male to female ratio was 5:1. Of those with unilateral hernias, 25.8% underwent contralateral exploration and in these cases a patent processus vaginalis was found in 68.9%. Bilateral hernias were more common in younger and female patients. At 2 years there was a recurrence rate of 0.99% and in 2.7% of patients a hernia was evident on the contralateral side (metachrony), and this was unrelated to the anesthesia technique., Conclusions: Bilateral hernias are associated with lower gestational age at birth and female gender. There was a low incidence of complications and the anesthesia technique did not affect surgical outcome., Level of Evidence: Level 1 evidence from prospective treatment study., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background/aims: The Nuss procedure is the most commonly performed operation to correct pectus excavatum (PE). Thoracoscopic assistance has been anecdotally noted to improve the safety of this operative approach. This study aimed to compare complications and clinical outcomes before and after the introduction of thoracoscopy in a single-center., Methods: A retrospective review was performed of all patients who underwent the Nuss procedure at The Royal Children's Hospital over an 11-year period (2005-2015), collecting data on all intra-operative and post-operative outcomes., Results: A total of 217 Nuss procedures were performed (122 non-thoracoscopic pectus repairs, 95 thoracoscopic pectus repairs). Median patient age was 14.9years, with the majority male (185/217, 84.3%). Patient demographics (age, gender, defect severity) and postoperative recovery were comparable between the two groups. Major complications included cardiac arrest requiring internal cardiac massage, hemothorax, pneumothorax, empyema, bar displacement and infection. The overall major complication rate was low (19/217, 8.8%); however, there was a significant reduction in major complications in the thoracoscopic pectus repair group (13.1% versus 3.2%, p=0.02)., Conclusions: Thoracoscopic vision during the Nuss procedure reduces the risk of major complications., Level of Evidence: Treatment study - Level III (Retrospective comparative study)., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: The BBraun Perfusor Space™ syringe driver is already in use by ambulance services and retrieval teams but has not previously been assessed for hyperbaric chamber use., Methods: Pump flow accuracy was tested at rates between 1 and 40 ml· h⁻¹ using three different brands of 50 ml syringe. Function of the occlusion alarms was assessed using the same syringes. The hyperbaric profile involved pressurisation to 284 kPa at 30 kPa· min⁻¹, 30 min at 284 kPa and decompression at 30 kPa· min⁻¹. Output was recorded from differences in weight of collection containers. A single device was tested., Results: Performance was highly dependent on the syringe type used, with two of the three 50 ml syringes used demonstrating 'stiction' at both low and high occlusion pressure alarm settings, most marked during pressurisation. On decompression from 284 kPa all syringes alarmed at significantly lower pressures. Because of the stiction problems only the flow measurements for the BBrown Omni¬ x 50 ml syringes are reported. At a pressure of 284 kPa, the difference between programmed and delivered rates was within the manufacturer's specification of 10%: at 40 ml· h⁻¹ (median variation 1.25%, IQR 0.5-1.7%), 10 ml· h⁻¹ (8.6%, IQR 8-9.2%), 5 ml· h⁻¹ (-8.8%, IQR - 1.6-8.8%) and 1 ml· h⁻¹ (-4%, IQR 4-12%). Pressurisation was associated with significantly lower flow rates whilst decompression was associated with significantly increased rates. Limited testing at 405 kPa was also within the manufacturer's specifications., Conclusion: A BBraun Infusor Space syringe driver performed within acceptable performance criteria but is highly dependent on syringe type and flow rates. The potential for the device to under deliver on pressurisation and over deliver on depressurisation, however, suggests vigilance and appropriate rate adjustments may be necessary during these phases.

Background: Pectus excavatum (PE) is the most common congenital chest wall deformity, occurring in 1 : 1000 children with a male to female ratio of 4 : 1. Several procedures have been described to manage this deformity, including cartilage resection with sternal osteotomy (the Ravitch procedure) and a minimally invasive repair technique (the Nuss procedure). While initially described as a nonthoracoscopic technique, the current surgical approach of the Royal Childrens Hospital involves thoracoscopic assistance. Postoperative pain is significant in patients undergoing the pectus repair and multiple analgesic regimens have been advocated with continuous thoracic epidural infusions and opioid infusions the most common. Some authors have advocated patient-controlled analgesia (PCA), paravertebral nerve blocks (PVNB), and wound infusion catheters as alternatives., Aims: The primary aim of this study was to assess our experience with postoperative pain and analgesia requirements associated with the minimally invasive repair of pectus excavatum in children., Methods: This is a retrospective cohort study with a contemporaneous comparison group examining patients treated between January 2005 and December 2015 for minimally invasive repair of pectus excavatum by the Nuss procedure., Results: Two hundred and seventeen patients [mean age 14.9 (sd 1.9) years] with pectus excavatum treated at the Royal Childrens Hospital between 2005 and 2015 were identified. All patients were managed with thoracic epidural analgesia and intravenous morphine infusions. The epidural was effective in the postanesthesia care unit in 97.3% (failure to place an epidural rate was 4 (1.9%); no block on awakening 0.9%). A further 4 (1.8%) were removed within 24 h. The mean morphine equivalent dose in the first 24 h was 0.8 mg·kg -1 ·day -1 . PCA was continued for a mean of 3.8 days and the total mean morphine equivalent dose was 2.2 mg·kg -1 ·day -1 . Minor complications occurred in 67 (30.9%) with postoperative nausea and vomiting in 36 patients (16.6%) and urinary retention requiring an indwelling catheter in 40 patients (18.4%)., Conclusion: An epidural-based analgesic regime is associated with low pain scores and few acute complications. The continuation of morphine analgesia after the first postoperative day is common but associated with an increased incidence of urinary retention and nausea and vomiting., (© 2016 John Wiley & Sons Ltd.)

Background: Infant spinal anesthesia with levobupivacaine has been promoted as a technique to reduce both the risk of postoperative apnea and exposure to volatile anesthesia. There is, however, no pharmacokinetic data to support the currently recommended doses., Aims: Our aim was to determine whether infant levobupivacaine spinal anesthesia is associated with plasma concentrations consistent with a low risk of local anesthetic systemic toxicity., Methods: This was an open-label pharmacokinetic safety and tolerability study of levobupivacaine spinal anesthesia in infants <55 weeks Post Menstrual Age undergoing lower abdominal surgery. Infants received a spinal anesthetic with levobupivacaine 1 mg·kg(-1) in the left lateral position., Results: Spinal anesthesia was successful in 25 (86.2%) of 29 infants (postmenstrual age 36-52 weeks; weight 2.2-4.7 kg). The median (IQR) total venous levobupivacaine plasma concentrations was 0.33 (0.25-0.42) μg·ml(-1) and unbound venous levobupivacaine was 19.5 (14.5-38) ng·ml(-1) . Median protein binding was 93.5 (91.4-96%). Alpha-1 acid glycoprotein concentrations were 0.25 (0.17-0.37) g·l(-1) and albumin concentrations were 29 (24-32) g·l(-1) ., Conclusion: Total plasma concentrations and unbound (free) concentration of levobupivacaine were consistently lower than concentrations reported in cases of pediatric local anesthetic toxicity. In a small number of infants requiring a repeat spinal of 1 mg·kg(-1) was also associated with acceptable total and free concentrations. We conclude that levobupivacaine at 1 mg·kg(-1) is associated with no systemic side effects in infants receiving awake spinal anesthesia., (© 2016 John Wiley & Sons Ltd.)

Introduction: The aim of this study was to review patients with iatrogenic cerebral gas embolism (CGE) referred to The Alfred Hospital hyperbaric unit to determine whether hyperbaric oxygen treatment (HBOT) reduced morbidity and mortality., Methods: This is a retrospective cohort study with a contemporaneous comparison group of patients referred between January 1998 and December 2014. The primary end point was good neurological outcome at the time of discharge from hospital or rehabilitation facility as assessed by the Glasgow Outcome Scale (GOS-E)., Results: Thirty-six patients were treated with HBOT for CGE and nine patients were diagnosed with CGE but did not receive HBOT. Thirty-two patients developed CGE from an arterial source and 13 from a venous source. The mean time from recognition of the event to institution of HBOT was 15 hours. Four of 45 patients (8.9%) died. Good neurological outcomes (defined as GOS-E 7 or 8) occurred in 27 patients and moderate disability in 13. The only independent factor that was associated with good neurological outcome was time to first HBOT (OR 0.94, 0.89-0.99; P = 0.05). Hemiplegia as the first presenting sign, however, was associated with poor outcome (OR 0.27, 0.06-1.08; P = 0.05). The source of embolus (arterial versus venous), hyperbaric treatment table used and patient age did not affect outcome., Conclusion: Appropriate treatment of CGE with hyperbaric oxygen was found to be impeded by delays in diagnosis and subsequent transfer of patients. Better neurological outcome was associated with HBOT within eight hours of CGE.

Introduction: The vast majority of freshwater cave diving in Australia occurs within the limestone caves of the Gambier karst in the south-east of South Australia. The incidence of decompression illness (DCI) in cave divers is presumed to be higher than open-water recreational divers because of the greater depths involved, but has not previously been reported. Our aim was to determine the incidence of DCI in cave divers, the patterns of diving and the outcome of hyperbaric treatment., Methods: This was a retrospective cohort study of cave divers with DCI presenting to the Royal Adelaide Hospital or The Alfred Hospital over a 10-year period between 2002 and 2012. We reviewed case notes of cave divers who were treated for DCI after diving in the Mt Gambier karst. As there are no records of the number of dives performed during the study period we generated a denominator for the incidence of DCI by extrapolating available data and making a number of assumptions about the number of dives per dive permit issued., Results: Sixteen patients were treated for DCI during the study period. The precipitating dive was a single deep decompression dive in seven cases, multiday repetitive dive sequences in eight and a non-decompression dive in one. Three of the 16 cases of DCI involved dives in excess of 90 metres' fresh water (mfw) using trimix. As the total estimated number of dives in the study period was approximately 57,000 the incidence of DCI in Australian cave divers was estimated to be 2.8:10,000 (0.028%). It is possible that the overall incidence of DCI is as high as 0.05%, and even higher when dives to depths greater than 90 mfw are involved., Conclusions: The estimated incidence of DCS in this series is lower than expected but consistent with other series describing DCI in cold-water recreational diving.

Background: Awake regional anesthesia (RA) is a viable alternative to general anesthesia (GA) for infants undergoing lower abdominal surgery. Benefits include lower incidence of postoperative apnea and avoidance of anesthetic agents that may increase neuroapoptosis and worsen neurocognitive outcomes. The General Anesthesia compared to Spinal anesthesia study compares neurodevelopmental outcomes after awake RA or GA in otherwise healthy infants. The aim of the study is to describe success and failure rates of RA and report factors associated with failure., Methods: This was a nested cohort study within a prospective, randomized, controlled, observer-blind, equivalence trial. Seven hundred twenty-two infants 60 weeks or less postmenstrual age scheduled for herniorrhaphy under anesthesia were randomly assigned to receive RA (spinal, caudal epidural, or combined spinal caudal anesthetic) or GA with sevoflurane. The data of 339 infants, where spinal or combined spinal caudal anesthetic was attempted, were analyzed. Possible predictors of failure were assessed including patient factors, technique, experience of site and anesthetist, and type of local anesthetic., Results: RA was sufficient for the completion of surgery in 83.2% of patients. Spinal anesthesia was successful in 86.9% of cases and combined spinal caudal anesthetic in 76.1%. Thirty-four patients required conversion to GA, and an additional 23 patients (6.8%) required brief sedation. Bloody tap on the first attempt at lumbar puncture was the only risk factor significantly associated with block failure (odds ratio = 2.46)., Conclusions: The failure rate of spinal anesthesia was low. Variability in application of combined spinal caudal anesthetic limited attempts to compare the success of this technique to spinal alone.

Background: Postoperative apnea is a complication in young infants. Awake regional anesthesia (RA) may reduce the risk; however, the evidence is weak. The General Anesthesia compared to Spinal anesthesia study is a randomized, controlled trial designed to assess the influence of general anesthesia (GA) on neurodevelopment. A secondary aim is to compare rates of apnea after anesthesia., Methods: Infants aged 60 weeks or younger, postmenstrual age scheduled for inguinal herniorrhaphy, were randomized to RA or GA. Exclusion criteria included risk factors for adverse neurodevelopmental outcome and infants born less than 26 weeks gestation. The primary outcome of this analysis was any observed apnea up to 12 h postoperatively. Apnea assessment was unblinded., Results: Three hundred sixty-three patients were assigned to RA and 359 to GA. Overall, the incidence of apnea (0 to 12 h) was similar between arms (3% in RA and 4% in GA arms; odds ratio [OR], 0.63; 95% CI, 0.31 to 1.30, P = 0.2133); however, the incidence of early apnea (0 to 30 min) was lower in the RA arm (1 vs. 3%; OR, 0.20; 95% CI, 0.05 to 0.91; P = 0.0367). The incidence of late apnea (30 min to 12 h) was 2% in both RA and GA arms (OR, 1.17; 95% CI, 0.41 to 3.33; P = 0.7688). The strongest predictor of apnea was prematurity (OR, 21.87; 95% CI, 4.38 to 109.24), and 96% of infants with apnea were premature., Conclusions: RA in infants undergoing inguinal herniorrhaphy reduces apnea in the early postoperative period. Cardiorespiratory monitoring should be used for all ex-premature infants.

Aims: Calcific uraemic arteriolopathy (CUA) or calciphylaxis is most commonly seen in end-stage renal disease and is associated with significant morbidity and mortality. The aim of this study was to determine whether hyperbaric oxygen therapy (HBOT) is effective in healing calciphylaxis lesions and to determine if there are any patient factors that can predict wound healing and patient survival., Methods: We identified by retrospective review all cases of CUA referred to our institution for treatment with HBOT. We documented the clinical and biochemical parameters of this patient population, the size and distribution of the lesions as well as wound outcomes and patient survival following treatment., Results: A total 46 patients were identified with CUA associated with renal failure. Of the 46 patients, only 34 received a full course of HBOT. The balance was deemed unsuitable for treatment or was unable to tolerate treatment and was palliated. Of the 34 patients that received a full course of HBOT, 58% showed improvement in their wound scores, with more than half of these patients having complete healing of their wounds. The balance did not benefit from the therapy and had a very poor prognosis. Those that benefited from HBOT survived on average for more than 3 years. The only factor significantly associated with improved wound healing and survival was diabetes., Conclusion: This retrospective analysis suggests a role for HBOT in the treatment of CUA with more than half of the treated patients benefiting and surviving for an average of more than 3 years., (© 2015 Asian Pacific Society of Nephrology.)

Background: Caudal anesthesia is a landmark-based technique with ultrasound guidance occasionally used in the absence of landmarks. The current surface landmark remains a popular approach due to its desirable success rate. However, incomplete ossification of the posterior vertebral elements can make this procedure for neonatal caudal anesthesia difficult. The aim of this study was to describe the anatomical relationship of the posterior superior iliac spines (PSISs) to the sacral cornua in infants using ultrasound., Methods: A total of 26 healthy infants (17 female; mean age 13 weeks) were scanned by an experienced radiologist in the prone position with hip and knee joints flexed. The PSISs and sacral cornua were identified clinically then using ultrasound to assess whether these markings corresponded with the clinical markings. The distance between the PSISs and the distance between the tip of the PSIS and tip of the sacral cornu were measured using ultrasound., Results: The PSISs were clinically identified in all babies, but the sacral cornua were not palpable in four babies (15%). The PSISs and sacral cornua were easily visualized using ultrasound in all participants. The mean distance between the two left and right PSISs was 3.4 ± 0.5 cm; the mean distance between the PSISs and cornu was 2.5 ± 0.5 cm on the left and right., Conclusion: This study showed that the current landmark (equilateral triangle) for infant caudal anesthesia is unreliable. Importantly, the sacral hiatus is clinically identifiable only if the sacral cornua are palpable; otherwise, using ultrasound is essential., (© 2015 John Wiley & Sons Ltd.)

The anatomy of the sacral hiatus and caudal canal is prone to significant variation, yet studies assessing this in the pediatric population remain limited. Awareness of the possible anatomical variations is critical to the safety and success of caudal epidural blocks, particularly when image guidance is not employed. This systematic review analyzes the available evidence on the clinical anatomy of the caudal canal in pediatric patients, emphasizing surface anatomy and internal anatomical variations. A literature search using three electronic databases and standard pediatric and anatomy reference texts was conducted yielding 24 primary and seven secondary English-language sources. Appreciating that our current landmark-guided approaches to the caudal canal are not well studied in the pediatric population is important for both clinicians and researchers., (© 2014 John Wiley & Sons Ltd.)

Background: Early negative postoperative behavior (e-PONB) is common in children and manifests itself as emergence agitation (EA), emergence delirium (ED), and pain. The objective of this prospective double blind, randomized, placebo-controlled trial was to determine whether IV clonidine or IV fentanyl prior to surgery modifies e-PONB in children., Methods: Ninety children scheduled for subumbilical surgery under sevoflurane anesthesia supplemented with regional anesthesia were randomized to either receive IV clonidine 2 mcg·kg(-1) , IV fentanyl 2 mcg·kg(-1) or placebo (IV saline) before surgery. Primary outcome measures were the incidence of EA, ED and pain during the first hour after awakening. Secondary outcome measures were side effects such as nausea and vomiting and delayed discharge from PACU., Results: Eighty-seven children (n = 29 per group) completed the study. EA was present in 10 children (six clonidine, none fentanyl, and four placebo, P = 0.04) whereas ED was observed in 20 children (nine clonidine, three fentanyl, and eight placebo P = 0.13). Sixteen children who received placebo had a CHIPPS score of ≥4 compared with nine children in fentanyl group and 18 children receiving clonidine (P = 0.04). Ten children receiving fentanyl vomited during the first postoperative day, compared with six children in placebo group and none in clonidine group (P = 0.003). Discharge from PACU was not affected., Conclusions: IV fentanyl before surgery but not IV clonidine modifies e-PONB in children undergoing lower abdominal surgery under general anesthesia supplemented with regional anesthesia. The use of fentanyl in this population was also associated with reduced pain scores after awakening but with significantly greater incidence of PONV., (© 2014 John Wiley & Sons Ltd.)

Objectives: To document the incidence of difficult intubation following mandibular distraction osteogenesis (MDO) in children with severe mandibular hypoplasia., Background: Syndromes associated with significant mandibular hypoplasia, especially Pierre Robin sequence, provide a challenge in airway management both in and out of the operating room. Mandibular advancement using mandibular distraction osteogenesis devices has been used in infants in an attempt to reduce the incidence of acute life-threatening airway obstruction. Whether MDO also reduces the incidence of difficult intubation has not been adequately described., Methods: A retrospective chart review of 51 infants with upper airway obstruction secondary to mandibular hypoplasia who required MDO between January 2002 and 2012. The primary outcome was the incidence of difficult or failed intubation. Secondary outcomes were the relationship between syndrome type and the incidence of difficult intubation., Results: Fifty-one PRS infants were identified. Twenty-eight patients had isolated PRS, six had syndromic PRS, seven had Treacher Collins syndrome, and 10 had another coexisting syndrome. Prior to mandibular distraction osteogenesis (MDO), the incidence of difficult intubation was 71%, with the highest incidence in patients with Treacher Collins syndrome (100%), sPRS syndrome (100%), and PRS (65%). Following MDO, the incidence of difficult intubation was 8.3%. The difference was statistically significant for all patients (Kruskal-Wallis rank test P = 0.0001) those with isolated PRS (P = 0.0001), syndromic PRS (P = 0.0023), and other syndromes (P = 0.0002), but not for Treacher Collins syndrome (P = 0.21). Three patients had pre existing tracheostomies., Conclusions: In a select group of infants with severe upper airway obstruction who have failed nonsurgical airway interventions, mandibular distraction osteogenesis reduces the incidence of difficult mask ventilation and difficult intubation. We were not able to compare the improvement in airway management to a comparable group of PRS infants who did not undergo surgical intervention. The improvement in laryngeal view was most marked for infants with isolated PRS but no significant benefit was demonstrated in infants with TCS., (© 2012 Blackwell Publishing Ltd.)

Objectives/aim: This randomized control trial was designed to evaluate the incidence of emergence delirium (ED) in preschool children receiving sevoflurane or desflurane anesthesia combined with an effective caudal block., Background: While ED has been described in children receiving sevoflurane or desflurane anesthesia, a direct comparison between the two agents using a validated ED assessment tool has not been reported previously., Methods/materials: Two hundred and sixty preschool children scheduled for elective sub-umbilical surgery were randomized to receive sevoflurane or desflurane anesthesia combined with a caudal block. ED was defined as a Paediatric Anesthesia Emergence Delirium scale (PAED) ≥ 10 points. A delirium-specific score (ED I) was calculated from the first three items of the PAED score (eye contact, purposeful actions, awareness of the surroundings) and a nonspecific score (ED II) from the last two items on the PAED score (restlessness and inconsolability) to test the hypothesis that some items of the PAED scale may better reflect clinical ED than others., Results: Thirty-one (25%) children in each group demonstrated ED after awakening with ED being of shorter duration in the desflurane group than the sevoflurane group. An ED I score of nine points had a sensitivity of 0.93 and a specificity of 0.94 for ED. An ED II score of five points had a sensitivity of 0.34 and specificity of 0.95 for ED., Conclusion: Sevoflurane and desflurane anesthesia were associated with similar incidences of ED in children undergoing sub-umbilical surgery and receiving effective regional anesthesia. High scores on the first three items of the PAED scale were highly correlated with ED. The items restlessness and inconsolability had lower sensitivity for the diagnosis of ED., (© 2012 Blackwell Publishing Ltd.)

Objectives and Aims: To document the incidence of difficult airway management and difficult intubation in the era of replacement therapy for Australian children with mucopolysaccharidosis (MPS)., Background: Medical treatment for MPS has developed significantly since 1980's with a large number of patients now being offered either bone marrow transplant or enzyme replacement. The impact of these therapies on the incidence of difficult airway management has not been adequately documented. Similarly, anesthesia techniques and airway devices have been developed, which are thought to have greatly increased the safety of managing these patients under anesthesia but their role in children with MPS has not been systematically described., Methods: A retrospective chart review of 17 patients with MPS who had received anesthetics at the Royal Children's Hospital during the time frame January 1998-January 2011. The primary outcome was the incidence of difficult or failed intubation. Secondary outcomes were the relationship between the incidence of difficult intubation and treatment with enzyme replacement therapy (ERT) or bone marrow transplantation., Results: Seventeen patients received 141 anesthetics for 214 procedures. Difficult face mask ventilation occurred in 20 anesthetics (14.2%). Difficult intubation occurred in 40 anesthetics (25%). Failed intubation occurred in two cases (1.6%).The incidence of difficult intubation was 12% in MPS I, 35% MPS II, 86.7% in MPS VI, and 0% in MPS III and IV., Conclusions: Hematopoietic stem cell transplantation prior to 2 years of age reduces the incidence of difficult mask ventilation and difficult intubation in children with MPS I. ERT was initiated late in the clinical course of MPS II and VI and induced improvements in upper airway patency but did not reduce the incidence of difficult airway management., (© 2012 Blackwell Publishing Ltd.)

Background: Accumulation of glycosaminoglycans is known to cause significant problems in the anesthetic management of children with mucopolysaccharidoses (MPS). Clinical and standard radiological evaluation may convey insufficient information about the upper airway and trachea in children with MPS. Multidetector computed tomography (MDCT) images have been used to define the central airway and previous studies have recommended this tool to assess the airway of children who are considered at risk of difficult intubation. However, MDCT has not been recommended in MPS children. The aim of this clinical scenario study was to verify whether information from MDCT reconstruction of the airway is useful in airway management planning of children with MPS., Methods: In a two phase questionnaire-based study, 26 pediatric anesthesiologists were asked to produce airway management plans for 5 children with MPS. An initial plan for airway control was reported after assessment of standard preoperative anesthetic charts. A subsequent airway strategy was then described after reviewing tracheal MDCT images of each patient., Results: MDCT images provided additional clinically-relevant information in 87% (95% CI: 79-92%) of the evaluations. Reduction of tracheal size was the most common finding provided by the MDCT images. After reviewing the MDCT images, anesthesiologists changed their primary airway device selection in 21% of the evaluations (P=0.01)., Conclusion: Airway reconstruction using MDCT images from a previous CT scan may provide a useful assessment tool for preoperative airway evaluation and planning in MPS children.

Background: Clonidine has the potential to significantly prolong the duration of caudal epidural anesthesia. We investigated the effect of the addition of clonidine to the MLAC of levobupivacaine in a randomized controlled dose-response trial., Methods: A group of 120 children aged <6 years of age received caudal anesthesia with levobupivacaine and 1, 2, or 3 μg·kg(-1) of clonidine. The MLAC was determined according to a Dixon-Massey protocol. The primary outcome was effective surgical anesthesia. Secondary outcomes were the duration of postoperative analgesia, postoperative pain scores, clonidine side effects, and time to hospital discharge., Results: The MLAC of caudal levobupivacaine was 0.106%, 0.077%, and 0.035% with 1, 2, and 3 μg·kg(-1) of clonidine, respectively. There were significant dose-dependent increases in median duration of analgesia. The incidence of delayed discharge, somnolence, and PONV was significantly increased in the 3 μg·kg(-1) of clonidine group., Conclusions: Clonidine produces a local anesthetic sparing effect with a dose-dependent decrease in levobupivacaine MLAC for caudal anesthesia. In addition, there is a dose-dependent prolongation of postoperative analgesia following lower abdominal surgery in children. A dose of 2 μg·kg(-1) of clonidine provides the optimum balance between improved analgesia and minimal side effects., (© 2010 Blackwell Publishing Ltd.)

Postoperative apnoea in ex-premature infants is inversely proportional to gestational age at birth and postmenstrual age (PMA). Spinal anaesthesia is an important technique in ex-premature infants as it reduces the risk of postoperative apnoea, provided intra-operative sedation is avoided. Recent studies have provided more data on recommended doses of local anaesthetics for infant spinal anaesthesia as well as adjuvants used to prolong the duration of surgical anaesthesia. Spinal anaesthesia is also used for surgical procedures other than inguinal hernia repair. There are a variety of reasons why awake regional is not the preferred technique for ex-premature infants undergoing lower abdominal surgery in many centres, and there is also controversy over the appropriate anaesthetic technique for outpatient surgery in infants <60 weeks PMA. A pragmatic decision analysis on the selection of anaesthetic techniques for inguinal hernia repair in infants is presented.

Background: Comparing the relative potency of new local anaesthetics such as levobupivacaine and ropivacaine with bupivacaine by the minimum local analgesic concentration model has not been described for neonatal spinal anaesthesia. This information is important to compare agents and to determine the most effective spinal dose., Methods: We performed a two-stage study to determine the ED50, the ED95, and the relative analgesic potency of isobaric spinal bupivacaine, levobupivacaine, and ropivacaine in infants. In phase 1, 81 infants were randomized in a Dixon-Massey study to describe the minimum local analgesic dose. In phase 2, a further 70 patients were randomly allocated to receive spinal anaesthesia with doses in the upper dose-response range to define the ED95., Results: The ED50 doses for bupivacaine, levobupivacaine, and ropivacaine were estimated by isotonic regression to be 0.30 mg kg(-1) [95% confidence interval (CI) 0.25-0.43], 0.55 mg kg(-1) (0.50-0.64), and 0.50 mg kg(-1) (0.43-0.64), respectively. The ED(95), respectively, of bupivacaine, levobupivacaine, and ropivacaine were 0.96 mg kg(-1) (95% CI 0.83-0.98), 1.18 mg kg(-1) (1.05-1.22), and 0.99 mg kg(-1) (0.73-1.50). The relative potency ratios at the ED(50) were bupivacaine:levobupivacaine 0.55 (95% CI 0.39-0.88), bupivacaine:ropivacaine 0.61 (0.41-1.00), and levobupivacaine:ropivacaine 1.09 (0.84-1.45)., Conclusions: Appropriate doses for infant spinal anaesthesia are 1 mg kg(-1) of isobaric 0.5% bupivacaine and ropivacaine and 1.2 mg kg(-1) of isobaric 0.5% levobupivacaine.

Background: Comparing relative potency of new local anesthetics, such as levobupivacaine and ropivacaine, by the minimum local analgesic concentration model has not been described for caudal anesthesia. Therefore, we performed a prospective, randomized, double-blind study to determine the minimum local analgesic concentrations of a caudal single shot of ropivacaine and levobupivacaine in children and to describe the upper dose-response curve., Methods: We performed a two-stage prospective, randomized, double-blind study comparing the dose-response curves of caudal ropivacaine and levobupivacaine in children. In phase 1, 80 boys were randomized to receive either ropivacaine or levobupivacaine. In the second phase a further 32 patients were randomly allocated to receive caudal anesthesia with doses designed to delineate the upper dose-response range (the 50% effective dose [ED(50)]-ED(95) range)., Results: There were no significant differences in ED(50) values for caudal ropivacaine and levobupivacaine. The ED(50) for levobupivacaine estimated from the Dixon Massey method was 0.069% (95% CI 0.056%-0.082%) and for ropivacaine was 0.075% (95% CI 0.058%-0.092%). Estimated by isotonic regression the ED(50) and ED(95) respectively of levobupivacaine were 0.068 (0.04-0.09) and 0.20% (95% CI 0.16%-0.24%). For ropivacaine ED 50 and ED95 were 0.066 (0.033-0.098) and 0.225% (95% CI 0.21%-0.24%)., Conclusions: In children receiving one minimum alveolar anesthetic concentration of sevoflurane, there were no significant differences in the ED(50) for caudal levobupivacaine and ropivacaine. The potency ratio at ED(50) was 0.92 and 0.89 at ED(95), indicating that caudal levobupivacaine and ropivacaine have a similar potency.

Introduction: Age influences the potency of anesthetic agents, but there is little information on how age influences MAC-awake. MAC-awake may be an important aspect of anesthesia potency for the prevention of awareness during anesthesia. The aim of this study was to measure MAC-awake in a range of ages in children., Methods: After institutional ethics approval and informed parental consent 60 children were enrolled; 20 in each of three age groups (2 to <5, 5 to <8 and 8-12 years). Children were excluded if they had opioids, sedative premedication or a procedure likely to cause any residual discomfort. All children had sevoflurane anesthesia. At the end of the procedure the sevoflurane was decreased to the target concentration. Once the target endtidal concentration was achieved it was maintained for 10 min before a standard stimulus was applied and an observer determined if the child was awake. The Dixon up-down method was used to determine progression of subsequent concentrations and MAC-awake (ED50) for the three age groups were obtained using the probit model., Results: This study found evidence for a difference in ED50 between age groups (P = 0.008). The MAC-awake was highest in the youngest group (0.66%) and similar in the older groups (0.45% and 0.43%)., Conclusion: Although MAC-awake changes with age, in the ages where awareness has been reported, MAC-awake was found to be relatively low, and therefore it seems unlikely that age-specific changes to MAC-awake are a cause for awareness in children aged 5-12 years.

Background: Ketamine is used increasingly in paediatric anaesthetic practice to prolong the action of a caudal block. This study was designed to determine if adding S(+)-ketamine 0.5 mg kg(-1) allows a lower concentration of levobupivacaine to be used for caudal anaesthesia without loss of clinical effectiveness., Methods: One hundred and sixty-four children (ASA I or II) aged 3 months-6 yr were randomly allocated to receive 1 ml kg(-1) of levobupivacaine 0.15% with 0.5 mg kg(-1) S(+)-ketamine (Group 1), levobupivacaine 0.175% with 0.5 mg kg(-1) S(+)-ketamine (Group 2), or levobupivacaine 0.2% (Group 3) by the caudal route. Pain, motor block, sedation, and requirement for postoperative analgesia were assessed up to 6 h after operation., Results: There was no significant difference between the groups in effectiveness at first surgical incision. Significantly lower analgesic requirements were reported in Group 2 compared with Group 3 at wakeup, 180 and 360 min after operation. Time to first rescue analgesia was longer in Group 2 compared with Group 1 or 3. Kaplan-Meier survival analysis of analgesia free time demonstrated a significant advantage of Group 2 over Groups 1 and 3 (log rank P=0.05). The incidence of postoperative motor block was not significantly different between the groups. No excess sedation or dysphoric reactions were observed in the ketamine groups., Conclusions: The addition of 0.5 mg kg(-1) S(+)-ketamine to levobupivacaine 0.175% for caudal analgesia for lower abdominal and urological surgery is significantly more effective in providing postoperative analgesia than levobupivacaine 0.15% with 0.5 mg kg(-1) S(+)-ketamine or levobupivacaine 0.2%.

Background: There is no consensus on the concentration or type of local anesthetic used for initiation of epidural anesthesia. The aim of this randomized, double-blind, controlled trial was to compare the clinical effectiveness of epidural administration of both levobupivacaine and bupivacaine in 0.2% and 0.25% concentrations in pediatric patients undergoing abdominal and urological surgery., Methods: One hundred and forty-one children scheduled for lower abdominal and urological surgery were randomized to receive 0.4-0.6 ml.kg(-1) epidural, 0.25% bupivacaine, 0.2% bupivacaine, 0.25% levobupivacaine or 0.2% levobupivacaine. Initial epidural volumes, onset times; hemodynamic consequences, postoperative pain scores and degree of residual postoperative motor block were all recorded., Results: There were no significant differences in the proportion of children with effective analgesia after incision [0.20% bupivacaine 97%, 0.25% bupivacaine 94%, 0.20% levobupivacaine 91%, 0.25% levobupivacaine 92% (P=0.73)] when a median volume of 0.55 ml.kg(-1) was used. There was no association between the volume used for thoracic, lumbar, or sacral epidural anesthesia and the effectiveness of the agents used. There was a significantly greater incidence of pain on awakening with the 0.2% solutions compared with the 0.25% solutions, but no differences in the incidence of residual motor block between groups., Conclusions: While there is no difference in the proportion of effective surgical anesthesia, the lower incidence of pain and distress with the 0.25% solutions suggests that this concentration has clinical advantages over the 0.2% solutions for pediatric epidural anesthesia.

Background: Our primary aim was to determine the minimum local anaesthetic dose (MLAD) defined as the median effective local anesthetic dose for spinal anesthesia in neonates. Secondary aims were to determine the dose-response curve for spinal anesthesia including the clinically relevant ED95 dose and to describe the duration of motor block following ropivacaine spinal anesthesia., Methods: Fifty neonates less than 55 weeks postmenstrual age (PMA) having inguinal hernia repair were enrolled. The study was performed in two stages. The MLAD dose of ropivacaine was determined by up-down sequential allocation. An expanded dose ranging study was then performed with dose escalation to doses predicted to fall in the ED50-95 range dose. Probit and logit analysis on all patients was used to compare ED50 with the value described by the Dixon-Massey method and to determine doses up to the ED95., Results: Fifty neonates with a mean PMA of 43 weeks and mean weight of 3.7 kg were enrolled. The motor block MLAD (95% confidence interval) determined by the Dixon-Massey method was 0.51 (0.38-0.64) mg x kg(-1). A logistic regression analysis of the results of all 50 patients confirmed the Dixon-Massey result. The ED50 (95% CI) was 0.50 (0.39-0.63) mg x kg(-1) with an estimated ED95 was 1.08 (0.70-1.67) mg x kg(-1). These values were confirmed by probit analysis. Overall the mean duration (95% confidence interval) of lower limb motor blockade was 60.0 min (51.5-68.5 min). The duration of anesthesia far exceeded surgical duration in all successful cases., Conclusions: Ropivacaine is an effective agent for spinal anesthesia in neonates at a recommended dose of 1.08 mg.kg(-1). The motor block duration, however, is significantly shorter than equivalent agents and highly variable in duration.

Background: Difficult intubation occurred during anaesthesia for removal of maxillary distraction devices in five of seven children with syndromal craniosynostoses (four with Apert, two with Pfeiffer and one with Crouzon syndrome)., Methods: Intubation was assessed in terms of laryngeal view and an established intubation difficulty score and had been straightforward before device insertion. Difficulty was induced by trismus due to device insertion and by increased maxillary prominence. This was compounded by preexisting mandibular hypoplasia. Cephalometric analysis, with each child acting as their own control, demonstrated anterior displacement of the maxilla and increased maxillary vertical height, as well as increased protuberance of the maxillary incisors., Results: All five difficult tracheal intubations were associated with preoperative Mallampati scores of 3 or 4 and the nine straightforward intubations with scores of 1 or 2. Maximal interincisor distance was less than the lower 95% confidence limit for age in all five children who were difficult to intubate at the time of device removal. No child had a failed intubation, but all had significantly increased intubation difficulty., Conclusions: In view of the risks of trauma, hypoxia and aspiration associated with difficult direct laryngoscopy, we recommend elective fibreoptic intubation at anaesthesia for removal of maxillary distraction osteogenesis devices in these children.

Background and Purpose: Neonates with vein of Galen aneurysmal malformations (VGAMs) presenting with cardiac failure have high morbidity and mortality, and outcomes are significantly better in those presenting in later childhood. Neurologic outcomes in survivors are perceived to be uniformly poor, which may lead to the neonate being denied treatment. We assessed outcomes of modern neonatal intensive care and endovascular embolization in a consecutive series of such neonates presenting with cardiac failure., Methods: Between 1996 and 1998, five infants (three male, two female) were diagnosed with symptomatic VGAMs in the first week of life, four of whom had intractable, high-output cardiac failure and underwent initial endovascular treatment. There were 15 endovascular procedures and one neurosurgical clipping in these five patients. Transarterial and transvenous routes were required, using multiple embolic agents. We emphasized the use of sonographically guided, percutaneous transtorcular-venous-access, moveable-core guidewire as an embolic agent; routine MR imaging; and MR angiography., Results: Immediate outcomes included control of cardiac failure with normal neurologic function in four (80%) patients and one (20%) death from intractable cardiac failure. On follow-up examination, three (60%) infants showed no evidence of neurologic abnormality or cardiac failure; one (20%) infant showed moderate developmental delay. Two have had no further shunting on angiography, one has minimal flow, and one is awaiting follow-up imaging., Conclusion: Endovascular therapy with modern neuroanesthetic and neurointensive care can provide good outcomes even in the highest-risk neonates with VGAMs and cardiac failure. If medical management of cardiac failure fails, and there is no evidence of gross cerebral parenchymal damage on imaging, urgent endovascular treatment is feasible and can reduce the almost-100% mortality otherwise expected, without invariably severe morbidity. Use of multiple embolization strategies in multiple stages usually is necessary in these patients, and novel approaches and embolic agents may be necessary.

The unbound and bound plasma concentration of bupivacaine in 50 infants less than 55 weeks postconceptual age was determined following combined spinal and epidural anaesthesia (csea). Plasma concentrations were determined at 15-min intervals up to 60 min postspinal anaesthesia. Maximum plasma bupivacaine levels were recorded between 45 and 60 min post CseA. Total plasma concentrations above a toxic threshold level of 4 microg.ml(-1) were recorded in 4% of patients and above 2.5 microg.ml(-1) in 10% of patients. Unbound bupivacaine levels were greater than a presumed toxic level of 0.25 microg.ml(-1) in 16% of cases and above 0.3 microg. ml(-1) in 14% of cases. A wide range of protein binding was measured (varying from 53.8-98.2%) and could not be correlated with standard indicators of local anaesthetic binding. Two neonates had brief apnoeas in the immediate perioperative phase but no adverse cardiac or central nervous system events attributable to the performance of Csea were demonstrated.