Background: Each year, hundreds of thousands of children require sedation/anesthesia to facilitate MRI scans. Anesthetic techniques for accomplishing sedation/anesthesia vary widely between institutions and providers, with unclear implications for patient safety. Aims:We sought to establish trends in anesthetic practice for pediatric MRI sedation/ anesthesia across a 7-year period and determine rates of adverse events, considering technique used, age, and ASA physical classification status (ASA-PS).Methods: Using established data resources, we analyzed 24 052 anesthetics performed by anesthesiologists for MRI scans between 5/1/2013 and 12/31/2019 on patients less than 18 years old, focusing on medications used, trends of use, and associated adverse events. Adverse events (hypoxia, hypotension, bradycardia) were defined by deviation from age norms and accessed via the electronic anesthetic record database. The Cochran-Armitage test was used to assess trends over time in categorical data, and one-way ANOVA was used to analyze continuous data. Multivariable logistic regression analysis was implemented to determine the independent associations between anesthetic technique and adverse events while adjusting for age, ASA-PS, and weight. Results:The most significant trends noted were a decrease in "propofol-only" anesthetic techniques and an increase in propofol and dexmedetomidine combination techniques. Mild desaturation (80-89% SpO 2 ) occurred in 4.22% of cases with more significant hypoxia much rarer (0.44% of cases having desaturation <70% SpO 2 ). Bradycardia occurred in 2.39% of cases and hypotension in 1.75% of cases. Major adverse events were rare. Conclusions:We provide the largest report of the nature of MRI sedation/anesthesia as practiced by anesthesiologists in a large children's hospital. We demonstrate that, even in a large system, anesthetic techniques are pliable and shift significantly over time. Our data also support a high level of safety within our system, despite a case mix likely higher in risk than those in most of the previously published studies.

Background:Patients with mucopolysaccharidoses (MPS) have physical changes to their airways over time. Due to the natural progression of their disease, these patients become more difficult to intubate as they get older. Aims:The aims of this study were to evaluate the difficulty of airway management in MPS patients over time, and to evaluate the effect of bone marrow transplant and/or enzyme replacement therapy on airway difficulty. Methods: A retrospective review of MPS patients presenting for surgery fromJanuary 2012 to May 2018 was performed. Patients were assigned to groups based on their ages at the time of surgery, number of intubation attempts, equipment used for intubation, difficulty of mask ventilation, and difficulty of laryngeal mask airway placement. The same designations were applied to patients with a history of a bone marrow transplant (BMT) and/or enzyme replacement therapy, and they were compared to patients of similar ages who had received no treatment. Logistic regression was used to determine the odds of difficult intubation. Results:One hundred and twenty-eight anesthetic records were reviewed. In 27 cases, the patient had a BMT and in 54 cases, the patient had received enzyme replacement therapy. Adults (18 years and older) had the highest likelihood of difficult intubation (OR 13.44,, P = 0.022). Mask ventilation and laryngeal mask airway placement were not significantly more difficult in any age groups. Bone marrow transplant did not improve airway management. A history of enzyme replacement therapy was associated with an increased risk of difficult intubation in patients under the age of 12. Conclusions:As patients with MPS get older, there is a progression toward difficult intubation. Mask ventilation and laryngeal mask airway placement does not become more difficult with age. Bone marrow transplantation did not affect airway difficulty in our population, while enzyme replacement therapy was associated with difficult intubations in younger patients. K E Y W O R D Sairway management, anesthesia, bone marrow transplantation, enzyme replacement therapy, intubation, mucopolysaccharidoses | 621 MADOFF et Al.

BACKGROUND: In patients presenting for pyloromyotomy, most practitioners prioritize rapid securement of the airway due to concern for aspiration. However, there is a lack of consensus and limited evidence on the choice between rapid sequence induction (RSI) and modified RSI (mRSI). METHODS: The medical records of all patients presenting for pyloromyotomy from May 2012 to December 2018 were reviewed. The risk of hypoxemia (peripheral oxygen saturation [Spo 2], <90%) during induction was compared between RSI and mRSI cohorts for all patients identified as well as in the neonate subgroup by univariate and multivariable logistic regression analysis. Complications (aspiration, intensive care unit admission, bradycardia, postoperative stridor, and hypotension) and initial intubation success for both cohorts were also compared. RESULTS: A total of 296 patients were identified: 181 in the RSI and 115 in the mRSI cohorts. RSI was associated with significantly higher rates of hypoxemia than mRSI (RSI, 30% [23%–37%]; mRSI, 17% [10%–24%]; P = .016). In multivariable logistic regression analysis of all patients, the adjusted odds ratio (OR) of hypoxemia for RSI versus mRSI was 2.8 (95% confidence interval [CI], 1.5–5.3; P = .003) and the OR of hypoxemia for multiple versus a single intubation attempt was 11.4 (95% CI, 5.8–22.5; P < .001). In multivariable logistic regression analysis of neonatal subgroup, the OR of hypoxemia for RSI versus mRSI was 6.5 (95% CI, 2.0–22.2; P < .001) and the OR of hypoxemia for multiple intubation versus single intubation attempts was 18.1 (95% CI, 4.7–40; P < .001). There were no induction-related complications in either the RSI and mRSI cohorts, and the initial intubation success rate was identical for both cohorts (78%). CONCLUSIONS: In infants presenting for pyloromyotomy, anesthetic induction with mRSI compared with RSI was associated with significantly less hypoxemia without an observed increase in aspiration events. In addition, the need for multiple intubation attempts was a strong predictor of hypoxemia. The increased risk of hypoxemia associated with RSI and multiple intubation attempts was even more pronounced in neonatal patients.