The radiological home: Pediatric anesthesiologist's role in risk assessment for imaging procedures

Hypotensive Events in Pediatric Patients Receiving Dexmedetomidine for MRI

PURPOSE

Dexmedetomidine, the preferred pediatric sedating agent for magnetic resonance imaging (MRI), has the side effect of hypotension. Newer recommendations for reporting adverse events in pediatric procedural sedation include using a two-pronged definition. Our aim was to describe the incidence of hypotension in patients undergoing sedated MRI and to identify demographic and clinical factors associated with hypotension, applying a two-pronged definition, where a numerical threshold/clinical criterion must be met as well as at least one clinical intervention performed.

DESIGN

An observational cohort study.

METHODS

Medical record data were extracted for outpatients less than 18 years of age sedated primarily with dexmedetomidine for MRI in a single center for over a seven-year period. Patients who received propofol as an adjunct were also included. Hypotension was defined using a two-pronged approach, as a 20% reduction in systolic blood pressure from baseline lasting ≥10 minutes, coupled with a fluid bolus. Analysis included descriptive statistics, t tests and logistic regression using discrete-time survival analysis.

FINDINGS

Of the 1,590 patient encounters, 90 (5.7%) experienced hypotension. Males were significantly more likely to have hypotension. Patients with hypotension had overall longer appointment times, including longer sedation times and recovery time. Greater blood pressure (BP) variability in the preceding 20 minutes also increased the risk of hypotension.

CONCLUSIONS

Our lower incidence of hypotension is likely related to the two-pronged intervention-based definition used, as it likely more accurately reflects clinically meaningful hypotension. To our knowledge, this is the first study using this approach with this population. Research further examining the relationship between prolonged sedation, blood pressure variability, gender, hypotension, and recovery time is needed. Understanding these relationships will help interdisciplinary teams, including nurses in pediatric procedural areas, to reduce the incidence of hypotension, potentially maximize patient safety, and optimize throughput.

Magnetic resonance imaging for congenital lung malformations

Congenital lung malformations are most often identified on prenatal US screening. Fetal MRI is often performed to further evaluate these lesions. Although some of these lesions might cause prenatal or early postnatal symptoms that require urgent management, the majority are asymptomatic at birth and might be subtle or invisible on chest radiographs. Postnatal imaging is frequently deferred until 3-6 months of age, when surgery or long-term conservative management is contemplated. High-quality imaging and interpretation is needed to assist with appropriate decision-making. Contrast-enhanced chest CT, typically with angiographic technique, has been the usual postnatal imaging choice. In this review, the author discusses and illustrates the indications and use of postnatal MR imaging for bronchopulmonary malformations as well as some differential diagnoses and the advantages and disadvantages of MR versus CT.

An update on pediatric sedation techniques in nonoperating room locations

PURPOSE OF REVIEW

To review advancements in care for pediatric patients in nonoperating room settings.

RECENT FINDINGS

Advances in patient monitoring technology, utilization of Child Life specialists, and alternative staffing models are helping anesthesia providers meet the rising demand for coverage of pediatric nonoperating room anesthesia (NORA) cases. The Wake Up Safe and Pediatric Sedation Research Consortium registries are exploring outcome measures regarding the safety of pediatric anesthesia in off-site locations and have reported an increased risk for severe respiratory and cardiac adverse events when compared to OR anesthesia sites. Additionally, malpractice claims for NORA have a higher proportion of claims for death than claims in operating rooms.

SUMMARY

Pediatric NORA requires thorough preparation, flexibility, and vigilance to provide safe anesthesia care to children in remote locations. Emerging techniques to reduce anesthetic exposure, improve monitoring, and alternative staffing models are expanding the boundaries of pediatric NORA to provide a safer, more satisfying experience for diagnostic and interventional procedures.

Predictors of Anesthetic Exposure in Pediatric MRI

BACKGROUND. Anesthetic exposure in children may impact long-term neurocognitive outcomes. Therefore, minimizing pediatric MRI scan time in children under anesthesia and the associated anesthetic exposure is necessary. OBJECTIVE. The purpose of this study was to evaluate pediatric MRI scan time as a predictor of total propofol dose, considering imaging and clinical characteristics as covariates. METHODS. Electronic health records were retrospectively searched to identify MRI examinations performed from 2016 to 2019 in patients 0-18 years old who received propofol anesthetic. Brain; brain and spine; brain and abdomen; and brain, head, and neck MRI examinations were included. Demographic, clinical, and imaging data were extracted for each examination, including anesthesia maintenance phase time, MRI scan time, and normalized propofol dose. MRI scan time and propofol dose were compared between groups using a t test. A multiple linear regression with backward selection (threshold, p < .05) was used to evaluate MRI scan time as a predictor of total propofol dose, adjusting for sex, age, time between scan and study end, body part, American Society of Anesthesiologists (ASA) classification, diagnosis, magnet strength, and IV contrast medium administration as covariates. RESULTS. A total of 501 examinations performed in 426 patients (172 girls, 254 boys; mean age, 6.55 ± 4.59 [SD] years) were included. Single body part examinations were shorter than multiple body part examinations (mean, 52.7 ± 18.4 vs 89.3 ± 26.4 minutes) and required less propofol (mean, 17.7 ± 5.7 vs 26.1 ± 7.7 mg/kg; all p < .001). Among single body part examinations, a higher ASA classification, oncologic diagnosis, 1.5-T magnet, and IV contrast medium administration were associated with longer MRI scan times (all p ≤ .009) and higher propofol exposure (all p ≤ .005). In multivariable analysis, greater propofol exposure was predicted by MRI scan time (mean dose per minute of examination, 0.178 mg/kg; 95% CI, 0.155-0.200; p < .001), multiple body part examination (p = .04), and IV contrast medium administration (p = .048); lower exposure was predicted by 3-T magnet (p = .04). CONCLUSION. Anesthetic exposure during pediatric MRI can be quantified and predicted based on imaging and clinical variables. CLINICAL IMPACT. This study serves as a valuable baseline for future efforts to reduce anesthetic doses and scan times in pediatric MRI.

Pediatric Anesthesia Outside the Operating Room: Safety and Systems

Anesthesia care performed outside the operating room is a growing area of pediatric anesthesia practice. The anesthesiology team expects to care for children in diverse locations, which include diagnostic and interventional radiology, gastroenterology and pulmonary endoscopy suites, radiation oncology sites, and the cardiac catheterization laboratory. To provide safe, high-quality care the anesthesiologist working in these environments must understand the unique environmental, logistical, and perioperative considerations and risks involved with each remote location. This 2-part review provides an overview of safety and system considerations in pediatric nonoperating room anesthesia before describing in more detail considerations for particular remote anesthetizing locations.

Practice horizons in pediatric nonoperating room anesthesia

PURPOSE OF REVIEW

Anesthesia outside the operating room is rapidly expanding for adult and pediatric patients. Anesthesia clinicians practicing in this area need a good understanding of the challenges of the NORA environment and the anesthetic risks and perioperative implications of practice so that they can deliver safe care to their patients.

RECENT FINDINGS

Recent reports from large patient databases have afforded anesthesiologists a greater understanding of the risk of NORA when compared to anesthesia in the operating room. Descriptions of advances in team training with the use of simulation have allowed the development of organized procedural teams. With an emphasis on clear communication, an understanding of individual roles, and a patient-centered focus, these teams can reliably develop emergency response procedures, so that critical moments are not delayed in an environment remote from usual assistance.

SUMMARY

With appropriate attention to organizational concerns (i.e. team environment, safety protocols) and unrelenting focus on patient safety, anesthesiologists can assist in safely providing the benefit of cutting-edge technical advancements to pediatric patients in these challenging environments.

Ultrafast pediatric chest computed tomography: comparison of free-breathing vs. breath-hold imaging with and without anesthesia in young children

BACKGROUND

General anesthesia (GA) or sedation has been used to obtain good-quality motion-free breath-hold chest CT scans in young children; however pulmonary atelectasis is a common and problematic accompaniment that can confound diagnostic utility. Dual-source multidetector CT permits ultrafast high-pitch sub-second examinations, minimizing motion artifact and potentially eliminating the need for a breath-hold.

OBJECTIVE

The purpose of this study was to evaluate the feasibility of free-breathing ultrafast pediatric chest CT without GA and to compare it with breath-hold and non-breath-hold CT with GA.

MATERIALS AND METHODS

Young (≤3 years old) pediatric outpatients scheduled for chest CT under GA were recruited into the study and scanned using one of three protocols: GA with intubation, lung recruitment and breath-hold; GA without breath-hold; and free-breathing CT without anesthesia. In all three protocols an ultrafast high-pitch CT technique was used. We evaluated CT images for overall image quality, presence of atelectasis and motion artifacts.

RESULTS

We included 101 scans in the study. However the GA non-breath-hold technique was discontinued after 15 scans, when it became clear that atelectasis was a major issue despite diligent attempts to mitigate it. This technique was therefore not included in statistical evaluation (86 remaining patients). Overall image quality was higher (P=0.001) and motion artifacts were fewer (P<.001) for scans using the GA with intubation and recruitment technique compared to scans in the non-GA free-breathing group. However no significant differences were observed regarding the presence of atelectasis between these groups.

CONCLUSION

We demonstrated that although overall image quality was best and motion artifact least with a GA-breath-hold intubation and recruitment technique, free-breathing ultrafast pediatric chest CT without anesthesia provides sufficient image quality for diagnostic purposes and can be successfully performed both without and with contrast agent in young infants.