Anesthesia management of neonates and infants requiring intraoperative neurophysiological monitoring: A concise review.

Intraoperative neurophysiological monitoring is currently used to prevent intraoperative spinal cord and nerve injuries during neonatal and infant surgeries. However, its use is associated with some issues in these young children. The developing nervous system of infants and neonates requires higher stimulation voltage than adults to ensure adequate signals, thereby necessitating reduced anesthesia dose to avoid suppressing motor and somatosensory-evoked potentials. Excessive dose reduction, however, increases the risk of unexpected body movement when used without neuromuscular blocking drugs. Most recent guidelines for older children and adults recommend total intravenous anesthesia with propofol and remifentanil. However, the measurement of anesthetic depth is less well understood in infants and neonates. Size factors and physiological maturation cause pharmacokinetics differences compared with adults. These issues make neurophysiological monitoring in this young population a challenge for anesthesiologists. Furthermore, monitoring errors such as false-negative results immediately affect the prognosis of motor and bladder-rectal functions in patients. Therefore, anesthesiologists need to be familiar with the effects of anesthetics and age-specific neurophysiological monitoring challenges. This review provides an update regarding available anesthetic options and their target concentration in neonates and infants requiring intraoperative neurophysiological monitoring.

Neurodevelopmental outcome at 5 years of age after general anaesthesia or awake-regional anaesthesia in infancy (GAS): an international, multicentre, randomised, controlled equivalence trial.

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.

Neurodevelopmental outcome at 2 years of age after general anaesthesia and awake-regional anaesthesia in infancy (GAS): an international multicentre, randomised controlled trial.

BACKGROUND: Preclinical data suggest that general anaesthetics affect brain development. There is mixed evidence from cohort studies that young children exposed to anaesthesia can have an increased risk of poor neurodevelopmental outcome. We aimed to establish whether general anaesthesia in infancy has any effect on neurodevelopmental outcome. Here we report the secondary outcome of neurodevelopmental outcome at 2 years of age in the General Anaesthesia compared to Spinal anaesthesia (GAS) trial. METHODS: In this international assessor-masked randomised controlled equivalence trial, we recruited infants younger than 60 weeks postmenstrual age, born at greater than 26 weeks' gestation, and who had inguinal herniorrhaphy, from 28 hospitals in Australia, Italy, the USA, the UK, Canada, the Netherlands, and New Zealand. Infants were randomly assigned (1:1) to receive either awake-regional anaesthesia or sevoflurane-based general anaesthesia. Web-based randomisation was done in blocks of two or four and stratified by site and gestational age at birth. Infants were excluded if they had existing risk factors for neurological injury. The primary outcome of the trial will be the Wechsler Preschool and Primary Scale of Intelligence Third Edition (WPPSI-III) Full Scale Intelligence Quotient score at age 5 years. The secondary outcome, reported here, is the composite cognitive score of the Bayley Scales of Infant and Toddler Development III, assessed at 2 years. The analysis was as per protocol adjusted for gestational age at birth. A difference in means of five points (1/3 SD) was predefined as the clinical equivalence margin. This trial is registered with ANZCTR, number ACTRN12606000441516 and ClinicalTrials.gov, number NCT00756600. FINDINGS: Between Feb 9, 2007, and Jan 31, 2013, 363 infants were randomly assigned to receive awake-regional anaesthesia and 359 to general anaesthesia. Outcome data were available for 238 children in the awake-regional group and 294 in the general anaesthesia group. In the as-per-protocol analysis, the cognitive composite score (mean [SD]) was 98.6 (14.2) in the awake-regional group and 98.2 (14.7) in the general anaesthesia group. There was equivalence in mean between groups (awake-regional minus general anaesthesia 0.169, 95% CI -2.30 to 2.64). The median duration of anaesthesia in the general anaesthesia group was 54 min. INTERPRETATION: For this secondary outcome, we found no evidence that just less than 1 h of sevoflurane anaesthesia in infancy increases the risk of adverse neurodevelopmental outcome at 2 years of age compared with awake-regional anaesthesia. FUNDING: Australia National Health and Medical Research Council (NHMRC), Health Technologies Assessment-National Institute for Health Research UK, National Institutes of Health, Food and Drug Administration, Australian and New Zealand College of Anaesthetists, Murdoch Childrens Research Institute, Canadian Institute of Health Research, Canadian Anesthesiologists' Society, Pfizer Canada, Italian Ministry of Heath, Fonds NutsOhra, and UK Clinical Research Network (UKCRN).

Apnea after Awake Regional and General Anesthesia in Infants: The General Anesthesia Compared to Spinal Anesthesia Study--Comparing Apnea and Neurodevelopmental Outcomes, a Randomized Controlled Trial.

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.

Impact of various anesthetic regimens on motor-evoked potentials in infants undergoing spinal surgery: A case series.

Motor-evoked potential (MEP) monitoring is commonly used in children. MEP monitoring in infants is difficult due to smaller signals requiring higher stimulation voltages. There is limited information on the effect of different anesthetics on MEP monitoring in this age group. This case series describes the effect of different anesthetic regimens on MEP monitoring in infants. Patients <1 year of age who underwent spinal surgery with MEP monitoring between February 2022 and July 2023 at a single tertiary care children hospital were reviewed. The motor-evoked potential amplitudes were classified into 4 levels based on the voltage in the upper and lower limbs (none, responded, acceptable, sufficient). "Acceptable" or "sufficient" levels were defined as successful monitoring. A total of 19 infants were identified, involving 3 anesthesia regimens: 4/19 (21.1%) cases were anesthetized with propofol/remifentanil total intravenous anesthesia (TIVA), 3/19 (15.8%) with propofol/remifentanil/low-dose sevoflurane and another 12/19 (63.2%) cases who initially received propofol/remifentanil/sevoflurane and were converted to propofol/remifentanil anesthesia intraoperatively. The 4 cases with propofol/remifentanil showed 20/32 (62.5%) successful monitoring points. In contrast, 6/24 (25%) successful points were achieved with propofol/remifentanil intravenous anesthesia/0.5 age-adjusted minimum alveolar concentration sevoflurane. In 12 cases converted from propofol/remifentanil/low-dose inhalational anesthetics to TIVA alone, successful MEP monitoring points increased from 46/96 (47.9%) to 81/96 (84.4%). Adding low-dose inhalation anesthetic to propofol-based TIVA suppresses MEP amplitudes in infants. The optimal anesthetic regimen for infants requires further investigation.

Navigating the shifting sands of filtering facepiece respirator provision during the COVID-19 pandemic: a system response for maximising staff safety.

INTRODUCTION: Personal protective equipment is essential to protect health workers and patients and to ensure confidence when dealing with aerosolised disease transmission. We describe the process for ensuring adequate filtering facepiece respirator (FFR) qualitative fit testing at a local level during the COVID-19 pandemic. METHODS: Cascaded training is described, which allowed rapid spreading of the testing process, with supervision allowing quality assurance throughout. Testing consisted of subjective 'fit checking', checking for leaks, followed by qualitative hood testing. RESULTS: The original respirators (3M 1870) had a hood test pass rate of 87.5%. Following identification of this as a non-renewable and unsustainable option, a domestically manufactured and sustainable Help-It P2 duckbill-type respirator was adopted as the primary FFR. The hood test pass rate for this respirator was only 54%. A third respirator was made available (3M 1860), with a high pass rate of 80% but also a limited and non-renewable resource. Algorithms were constructed highlighting different proportional use of the respirators depending on the most limited resource. CONCLUSION: The testing format used is simple, reproducible and can be used by any hospital organisation when occupational health and safety departments are unable to provide the service during overwhelming demand. Qualitative fit testing is a scalable and effective method for ensuring appropriately sized and shaped FFRs, minimising resource consumption in the process. The use of a product with appropriate filtration capacity but a lower fit test pass rate (domestic duckbill respirator) as a replaceable resource facilitated adequate respirator availability for staff that would otherwise not have been possible. The provision of an FFR fit registry allows an organisation to make appropriate respirators available to staff from different sources as supply and demand changes.

The self-inflating bulb as an airway adjunct: is it reliable in children weighing less than 20 kilograms?

OBJECTIVES: To confirm the ability of the self-inflating bulb to indicate endotracheal tube (ETT) position in children weighing less than 20 kilograms, and to determine whether the presence of air in the stomach affects the bulb's accuracy. METHODS: This single-blind, prospective, single-cohort, repeated-measures, equivalence study was conducted in the operating room of a children's hospital. Seventy patients weighing less than 20 kilograms were enrolled. All patients had an uncuffed ETT placed in both the trachea and the esophagus. Measurements were initially obtained on both tubes without the presence of air in the stomach using the on-deflate method (the bulb is compressed after attachment to the ETT). Five mL/kg of air was then insufflated into the stomach and two additional measurements were obtained on each patient. The order in which the bulb was checked was determined by a computer-generated permuted block randomization scheme. The blinded assessor told the anesthesiologist when to start and stop the clock after each intervention. Five seconds was used as the cutoff time for which the clock was stopped. If the bulb re-expanded within 5 seconds, then the tube was considered to be in the trachea; if it did not re-expand, then this was considered to be an esophageal intubation. RESULTS: Median patient age was 2 years. The on-deflate method without air in the stomach had a sensitivity of 100% and a specificity of 94% for detecting tracheal intubations. With air in the stomach, the bulb had a sensitivity of 97% and a specificity of 96% (95% confidence interval [95% CI] for the difference between methods: sensitivity -3 to 10; specificity -10 to 7). The inaccuracy rate for the on-deflate method without air in the stomach was 3%, whereas the inaccuracy rate with air in the stomach was 4% (Delta -1, 95% CI = -5 to 4). There were no false positives or false negatives in the 24 patients weighing between 5 and 10 kilograms. CONCLUSIONS: The self-inflating bulb is a reliable method of detecting endotracheal tube position in children weighing less than 20 kg, even with the use of uncuffed endotracheal tubes. Furthermore, the presence of air in the stomach, simulating field conditions, does not affect bulb effectiveness in detecting endotracheal tube position.

Bradycardia with sevoflurane in siblings with Branchio-oto-renal syndrome.

Branchio-oto-renal syndrome (BOR, Melnick-Fraser syndrome, MIM#113650) refers to a rare autosomal dominant disorder characterized by branchial cysts or fistulas, hearing loss, external ear malformation, preauricular pits and renal abnormalities. The authors present three episodes of significant bradycardia in two siblings diagnosed with BOR syndrome during the sevoflurane general anesthesia. There is no published experience of anesthesia with this syndrome. Bradycardia occurred variously at induction, maintenance and immediately prior to emergence and required surgical stimulation, atropine, or epinephrine to treat. We seek to raise awareness of the potential for bradycardia during the procedures in patients with this syndrome requiring volatile anesthesia, especially sevoflurane.

The self-inflating bulb as an esophageal detector device in children weighing more than twenty kilograms: a comparison of two techniques.

STUDY OBJECTIVES: We confirm the ability of the self-inflating bulb to indicate endotracheal tube position in children and determine which method of bulb compression is more accurate. METHODS: This single-blind, prospective, single cohort, repeated measures comparison of the on-deflate and the off-deflate methods of bulb compression was conducted in the operating room of a children's hospital. Seventy-five patients weighing more than 20 kg were enrolled. All patients had an endotracheal tube placed in both the trachea and the esophagus, 5 mL/kg of air was insufflated into the stomach, and 4 measurements were obtained on each patient. The bulb was either applied to the endotracheal tube and then compressed (on-deflate method), or compressed before its attachment to the endotracheal tube (off-deflate method). The order in which the methods were utilized was determined by a computer-generated permuted block randomization scheme. The blinded assessor told the anesthesiologist when to start and stop the clock after each intervention. Five seconds was used as the cut-off time for which the clock was stopped. If the bulb reexpanded within 5 seconds, then the tube was considered to be in the trachea; if it did not reexpand, then this was considered to be an esophageal intubation. RESULTS: The mean patient age was 11 years. The on-deflate method had a sensitivity of 99% and a specificity of 92% for detecting tracheal intubations. The off-deflate method had a sensitivity of 99% and a specificity of 100% (95% confidence interval [CI] for the difference between methods: sensitivity -6 to 6, specificity -14 to 0.4). The inaccuracy rate for the off-deflate method was 1%, whereas the inaccuracy rate for the on-deflate method was 5% (Delta4; 95% CI 0.2 to 9). CONCLUSION: The self-inflating bulb is a reliable method of detecting endotracheal tube position in children. Furthermore, the off-deflate method may be more reliable and accurate than the on-deflate method when used in children weighing more than 20 kg.