Induction of anesthesia with sevoflurane in children: Curiosities and controversies.

Inhalational inductions with sevoflurane (up to 8% inspired concentration) have been the standard for inducing anesthesia in children for over three decades. However, when sevoflurane was first introduced, clinicians reported isolated cases of unexpected myoclonic jerking movements during the induction in children without epilepsy. These cases raised concerns regarding the widespread use of sevoflurane particularly after reports of seizures and epileptiform electroencephalographic (EEG) discharges surfaced. The latter reports prompted recommendations to reduce the concentration of sevoflurane during induction of anesthesia. More recently, a shift away from the use of nitrous oxide has prompted some to question whether sevoflurane has a role as an induction agent in children. The preponderance of evidence supports the practice of safely inducing anesthesia with 8% sevoflurane with or without nitrous oxide in children but recommended strategies to mitigate against epileptiform discharges may be more harmful than beneficial.

Changes in the cuff pressure in neonates in the absence of nitrous oxide.

BACKGROUND: Changes in the pressure of cuffed neonatal size tracheal tubes (TT) during anaesthesia without nitrous oxide are not well described. We determined whether the cuff pressure changes over time in neonates under general anaesthesia without nitrous oxide. METHODS: The airways of thirty neonates were secured with a high volume low pressure cuffed TT for meningocele surgery. The cuff was manually inflated until there was no audible leak and maintained at 10-15 cm H2O throughout by monitoring the pressure continuously with both a manometer and a pressure transducer. At baseline, the cuff pressure was assessed in the supine and then prone positions. During surgery, if the pressure exceeded 15 cm H2O, the cuff was deflated to < 15 cm H2O and if it was < 10 cm H2O, the cuff was inflated to 10-15 cm H2O. The time interval between corrections and the number of corrections were recorded. RESULTS: The cuff pressures in 18 neonates (60%) required correction during surgery. The cuff pressure exceeded 15 cm H2O in nine neonates (30%) and was corrected. The cuff pressures in 13 neonates were less than 10 cm H2O and required correction. The gender, weight, height, and duration of anaesthesia did not differ significantly between neonates who required correction of the cuff pressure and those who did not. Mean cuff pressures were similar at 15, 45, and 75 minutes of anaesthesia. CONCLUSIONS: In 60% of neonates undergoing surgery in the prone position under general anaesthesia without nitrous oxide, the cuff pressure exceeded 15 cm H2O. In such cases, cuff pressure should be monitored continuously throughout the surgery.

Pro-Con Debate: 1- vs 2-Hour Fast for Clear Liquids Before Anesthesia in Children.

Perioperative fasting guidelines are designed to minimize the risk of pulmonary aspiration of gastrointestinal contents. The current recommendations from the American Society of Anesthesiologists (ASA) and the European Society of Anaesthesiology and Intensive Care (ESAIC) are for a minimum 2-hour fast after ingestion of clear liquids before general anesthesia, regional anesthesia, or procedural sedation and analgesia. Nonetheless, in children, fasting guidelines also have consequences as regards to child and parent satisfaction, hemodynamic stability, the ability to achieve vascular access, and perioperative energy balance. Despite the fact that current guidelines recommend a relatively short fasting time for clear fluids of 2 hours, the actual duration of fasting time can be significantly longer. This may be the result of deficiencies in communication regarding the duration of the ongoing fasting interval as the schedule changes in a busy operating room as well as to poor parent and patient adherence to the 2-hour guidelines. Prolonged fasting can result in children arriving in the operating room for an elective procedure being thirsty, hungry, and generally in an uncomfortable state. Furthermore, prolonged fasting may adversely affect hemodynamic stability and can result in parental dissatisfaction with the perioperative experience. In this PRO and CON presentation, the authors debate the premise that reducing the nominal minimum fasting time from 2 hours to 1 hour can reduce the incidence of prolonged fasting and provide significant benefits to children, with no increased risks.

Association of anesthesia type with prolonged postoperative intubation in neonates undergoing inguinal hernia repair.

PURPOSE: The purpose of this study is to determine factors associated with prolonged intubation after inguinal herniorrhaphy in neonates. METHODS: Retrospective, single institution review of neonates undergoing inguinal herniorrhaphy between 2010 and 2018. Variables recorded included demographics, comorbidities, ventilation status at time of hernia repair, and anesthetic technique. RESULTS: We identified 97 neonates (median corrected gestational age 39.9 weeks, IQR 6.6). The majority (87.6%) received general anesthesia (GA); the remainder received caudal anesthesia (CA). Among the GA subjects, 25.8% remained intubated for at least 6 h after surgery, whereas none of the CA patients required intubation postoperatively (p = 0.03). Two risk factors associated with prolonged postoperative intubation: a history of intubation before surgery (p = 0.04) and a diagnosis of bronchopulmonary dysplasia (p = 0.03). CONCLUSIONS: Neonates undergoing inguinal herniorrhaphy under GA have a greater rate of prolonged postoperative intubation compared with those undergoing CA. A history of previous intubation and bronchopulmonary dysplasia were significant risk factors for prolonged postoperative intubation.

Glottic views using a Miller size 0 blade are superior to those from a Macintosh size 0 blade in neonates: a randomized trial.

INTRODUCTION: Both the Miller and Macintosh blades are commonly used during laryngoscopy in infants and children, although the glottic views have not been compared in neonates. This study compared the glottic views with the Miller and Macintosh size 0 blades in neonates when the blades were placed above and below the epiglottis. MATERIAL AND METHODS: Forty anaesthetized and paralyzed neonates undergoing elective surgery were enrolled and randomized to either the Miller or Macintosh size 0 blade. Two glottic views were obtained in random order in each neonate and were photographed using the same blade: lifting the epiglottis first then the tongue base or vice versa. The percentage of glottic opening (POGO) scores were evaluated with each view. The POGO scores and cardiorespiratory variables were then analysed. RESULTS: The POGO scores using the Miller blade to lift both the epiglottis and the tongue base were similar, whereas the scores using the Macintosh blade to lift the epiglottis were greater than those to lift the tongue base. The POGO scores using the Miller blade in both positions were significantly greater than those using the Macintosh blade in the corresponding positions (P = 0.0001). The heart rate using the Miller blade was greater than that using the Macintosh blade (P = 0.0001). CONCLUSIONS: In neonates, the glottic views using the Miller size 0 blade to lift both the epiglottis and the tongue base were deemed to be excellent and superior to those using the Macintosh blade in both positions.

The Effects of a Shoulder Roll During Laryngoscopy in Infants: A Randomized, Single-Blinded, Crossover Study.

BACKGROUND: The use of a shoulder roll to view the glottic opening during direct laryngoscopy in infants has been recommended but is not evidence based. METHODS: Twenty infants with normal airways, <6 months of age undergoing elective surgery under general anesthesia were randomized to undergo direct laryngoscopy first with a 2-inch vertical shoulder roll and then without, or vice versa. The primary outcome was the difference in the vertical distance between the angle of the laryngoscopist's eye and the operating room table in the 2 positions. Also, the views of the glottic opening in both positions were recorded for each infant and analyzed by a blinded investigator using the percent of glottic opening (POGO). RESULTS: Twenty infants completed the study without complications. The vertical distance did not differ significantly whether the shoulder roll was placed first or second, and there was no evidence of a differential carryover effect in the crossover design (P = .268). The main effect of the shoulder roll on the mean (95% confidence interval [CI]) vertical distances without 47.8 cm (43.5-52.1) and with the shoulder roll 37.2 cm (33.3-41) yielded a mean (95% CI) vertical difference of 10.6 cm (9.3-11.79; P = .0001). The median (interquartile range [IQR]) POGO scores without 100 [86.2, 100] and with the shoulder roll 97.5 [80, 100] did not differ (median difference [95% CI]: 0 [-20 to 0]; P = .39). CONCLUSIONS: A 2-inch shoulder roll lowers the line of sight of the glottic opening compared with no shoulder roll, without affecting the view of the glottic opening during laryngoscopy in infants.

Modifying a Full-Face Snorkel Mask to Meet N95 Respirator Standards for Use With Coronavirus Disease 2019 Patients.

We evaluated a full-face snorkel mask with an airway circuit filter to protect health care providers against airborne pathogens. First, a quantified N95 fit test was performed using aerosolized saline. Second, cardiorespiratory variables (heart rate, peripheral oxygen saturation, end-tidal carbon dioxide tension, and inspired fraction of carbon dioxide) were measured at rest and during moderate exercise. The modified mask passed the United States Occupational Safety and Health Administration (OSHA) N95 respirator (N95) fit test requirements with a fit factor of 142. Neither hypercapnia nor hypoxemia occurred. This modified mask has the potential to protect providers who care for patients with coronavirus disease 2019 (COVID-19).

A randomized trial of the glottic views with the classic Miller, Wis-Hipple and C-MAC (videolaryngoscope and direct views) straight size 1 blades in young children.

STUDY OBJECTIVE: The Miller and Wis-Hipple size 1 blades are widely used for laryngoscopy in children and the C-MAC straight blade is used increasingly in young children, although the glottic views with these blades have not been compared. To determine whether the glottic views with these blades are equivalent. DESIGN: Equivalent study. SETTING: Operating room. PATIENTS: 96 children <2 years, ASA 1 or 2, elective surgery requiring orotracheal intubation. INTERVENTIONS: Direct laryngoscopy with the Miller and Wis-Hipple or C-MAC (videolaryngoscope and direct view) straight blades size 1; photographs of the glottic opening. MEASUREMENTS: Percent of glottic opening (POGO) was measured using a standardized scale by a blinded investigator. Heart rate, systolic blood pressure and hemoglobin oxygen saturation were measured before and after laryngoscopy. RESULTS: The POGO scores with the four blades/views were equivalent (fewer than 20% of the views yielded POGO scores <80). However, a post hoc comparison of the POGO scores yielded significant differences (P = 0.0001); the C-MAC videolaryngoscope view yielded significantly better scores than the Miller, Wis-Hipple and direct C-MAC views (P = 0.0009, 0.0002 and 0.0001 respectively). The POGO score with the Miller blade was superior to that with the direct C-MAC view (P = 0.024). No adverse events or complications occurred. CONCLUSION: The four blades/glottic views were equivalent, although a post hoc analysis demonstrated that the glottic view with the C-MAC videolaryngoscope was superior overall and the view with the Miller size 1 was superior to that with the direct C-MAC view.

Tracking tidal volume noninvasively in volunteers using a tightly controlled temperature-based device: A proof of concept paper.

INTRODUCTION: There is a paucity of noninvasive respiratory monitors for patients outside of critical care settings. The Linshom respiratory monitoring device is a novel temperature-based respiratory monitor that measures the respiratory rate as accurately as capnography. OBJECTIVES: Determine whether the amplitude of the Linshom temperature profile was an accurate, surrogate and qualitative metric of the tidal volume (VT ) that tracks VT in healthy volunteers. METHODS: Forty volunteers breathed room air spontaneously through a tight-fitting continuous positive airway pressure mask with a Linshom device mounted in the mask. VT was measured contemporaneously using a standalone Maquet Servo-i ICU ventilator. The amplitudes of the Linshom temperature profiles were paired with the contemporaneous VT measurements using least squares linear regression analysis and the coefficient of variation (R2 ) was determined. RESULTS: Forty volunteers completed the study. The data from 30 of the volunteers were analysed and are presented; data from 10 volunteers were not included due to protocol violations and/or technical issues unrelated to Linshom. The fluctuations in the amplitude of the Linshom temperature profiles mapped closely with the measured VT using least squares linear regression analyses yielding a mean R2 (95% CI) value of 0.87 (0.84-0.90). CONCLUSION: These results support the notion that the Linshom temperature profile is an accurate and reliable surrogate that tracks changes in VT in healthy volunteers. Further studies are warranted in patients in clinical settings to establish the effectiveness of this monitor.

Pediatric ambulatory anesthesia: an update.

PURPOSE OF REVIEW: Ambulatory surgery is the standard for the majority of pediatric surgery in 2019 and adenotonsillectomy is the second most common ambulatory surgery in children so it is an apt paradigm. Preparing and managing these children as ambulatory patients requires a thorough understanding of the current literature. RECENT FINDINGS: The criteria for undertaking pediatric adenotonsillectomy on an ambulatory basis, fasting after clear fluids, postoperative nausea and vomiting (PONV), perioperative pain management and discharge criteria comprise the themes addressed in this review. SUMMARY: Three criteria determine suitability of adenotonsillectomy surgery on an ambulatory basis: the child's age, comorbidities and the severity of the obstructive sleep apnea syndrome (OSAS). Diagnosing OSAS in children has proven to be a challenge resulting in alternate, noninvasive techniques, which show promise. Abbreviating the 2 h clear fluid fasting guideline has garnered attention, although the primary issue is that parents do not follow the current clear fluid fasting regimen and until that is resolved, consistent fasting after clear fluids will remain elusive. PONV requires aggressive prophylactic measures that fail in too many children. The importance of unrecognized genetic polymorphisms in PONV despite prophylactic treatment is understated as are the future roles of palonosetron and Neurokinin-1 receptor antagonists that may completely eradicate PONV when combined with dexamethasone. Pain management requires test doses of opioids intraoperatively in children with OSAS and nocturnal desaturation to identify those with reduced opioid dosing thresholds, an uncommon practice as yet. Furthermore, postdischarge nonsteroidal anti-inflammatory agents as well as other pain management strategies should replace oral opioids to prevent respiratory arrests in those who are ultra-rapid CYP2D6 metabolizers. Finally, discharge criteria are evolving and physiological-based criteria should replace time-based, reducing the risk of readmission.

Drug Calculation Errors in Anesthesiology Residents and Faculty: An Analysis of Contributing Factors.

BACKGROUND: Limited data exist regarding computational drug error rates in anesthesia residents and faculty. We investigated the frequency and magnitude of computational errors in a sample of anesthesia residents and faculty. METHODS: With institutional review board approval from 7 academic institutions in the United States, a 15-question computational test was distributed during rounds. Error rates and the magnitude of the errors were analyzed according to resident versus faculty, years of practice (or residency training), duration of sleep, type of question, and institution. RESULTS: A total of 371 completed the test: 209 residents and 162 faculty. Both groups committed 2 errors (median value) per test, for a mean error rate of 17.0%. Twenty percent of residents and 25% of faculty scored 100% correct answers. The error rate for postgraduate year 2 residents was less than for postgraduate year 1 (P = .012). The error rate for faculty increased with years of experience, with a weak correlation (R = 0.22; P = .007). The error rates were independent of the number of hours of sleep. The error rate for percentage-type questions was greater than for rate, dose, and ratio questions (P = .001). The error rates varied with the number of operations needed to calculate the answer (P < .001). The frequency of large errors (100-fold greater or less than the correct answer) by residents was twice that of faculty. Error rates varied among institutions ranged from 12% to 22% (P = .021). CONCLUSIONS: Anesthesiology residents and faculty erred frequently on a computational test, with junior residents and faculty with more experience committing errors more frequently. Residents committed more serious errors twice as frequently as faculty.

Evaluating Patient-Centered Outcomes in Clinical Trials of Procedural Sedation, Part 2 Safety: Sedation Consortium on Endpoints and Procedures for Treatment, Education, and Research Recommendations.

The Sedation Consortium on Endpoints and Procedures for Treatment, Education, and Research, established by the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks, a public-private partnership with the US Food and Drug Administration, convened a second meeting of sedation experts from a variety of clinical specialties and research backgrounds to develop recommendations for procedural sedation research. The previous meeting addressed efficacy and patient- and/or family-centered outcomes. This meeting addressed issues of safety, which was defined as "the avoidance of physical or psychological harm." A literature review identified 133 articles addressing safety measures in procedural sedation clinical trials. After basic reporting of vital signs, the most commonly measured safety parameter was oxygen saturation. Adverse events were inconsistently defined throughout the studies. Only 6 of the 133 studies used a previously validated measure of safety. The meeting identified methodological problems associated with measuring infrequent adverse events. With a consensus discussion, a set of core and supplemental measures were recommended to code for safety in future procedural clinical trials. When adopted, these measures should improve the integration of safety data across studies and facilitate comparisons in systematic reviews and meta-analyses.

Perioperative considerations for airway management and drug dosing in obese children.

PURPOSE OF REVIEW: Childhood obesity, a phenomenon that is increasing globally, holds substantial relevance for pediatric anesthesia. In particular, understanding the nuances of airway management and drug dosing in obese children can be daunting. RECENT FINDINGS: Respiratory adverse events and challenges in managing the airway may be anticipated. In addition, drug-dosing strategies for the obese child are complex and poorly understood although recent advances have clarified the optimal dosing for anesthetics in these children. SUMMARY: Theoretical knowledge, practical skills, meticulous risk stratification and optimal drug regimens are crucial to ensure the safe conduct of anesthesia for obese children.