Oxymetazoline and hypertensive crisis in a child: can we prevent it?

BACKGROUND: Oxymetazoline nasal spray is not FDA approved for use in children less than 6 years; however, its safety and efficacy are widely accepted, and it is in widespread use in children prior to procedures that may lead to epistaxis. We report a case of intraoperative oxymetazoline toxicity in a 4-year-old boy that led to a hypertensive crisis. While examining the possible causes for this problem, we became aware that the method of drug delivery led to an unanticipated overdose. The position in which the bottle is held causes pronounced variation in the quantity of oxymetazoline dispensed. METHODS: To examine the impact that bottle position has on the volume delivered, we measured the volume of oxymetazoline dispensed with the bottle in the upright and inverted position. We also measured the volume of a drop of oxymetazoline dispensed from the bottle. Because an additional source of oxymetazoline exposure is from packing the nares with surgical pledgets, we analyzed the volume of oxymetazoline absorbed by each pledget. RESULTS: Squeezing the bottle in the upright position results in a fine spray of fluid that averaged 28.9 ± 6.8 µl and was largely independent of effort. This volume is nearly identical to the measured volume of a drop of oxymetazoline, which was 30 µl. However, squeezing the bottle in the inverted position resulted in a steady stream of fluid, and the volume administered was completely effort dependent. Multiple tests in the inverted position demonstrated an average volume of 1037 ± 527 µl, with a range of 473-2196 µl. Lastly, the volume of oxymetazoline absorbed by each surgical pledget was 1511 ± 184 µl. DISCUSSION: Our testing indicates that bottle position during oxymetazoline administration can cause up to a 75-fold increase in intended drug administration.

Supplemental oxygen causes increased signal intensity in subarachnoid cerebrospinal fluid on brain FLAIR MR images obtained in children during general anesthesia.

PURPOSE: To prospectively test the hypothesis that high levels of the fraction of inspired oxygen (Fio(2)) during general anesthesia cause subarachnoid cerebrospinal fluid (CSF) hyperintensity during fluid-attenuated inversion-recovery (FLAIR) magnetic resonance (MR) imaging. MATERIALS AND METHODS: At brain MR imaging during general anesthesia with propofol, two FLAIR sequences were performed in 20 children with American Society of Anesthesiologists physical status classification system grades of 3 or lower. The first FLAIR sequence was performed with the child breathing 100% oxygen; the second was performed with the child breathing 30% oxygen. CSF signal intensity was quantified on a three-point ordinal scale (0 = hypointense to brain parenchyma, 1 = isointense to brain parenchyma, 2 = hyperintense to brain parenchyma) by a pediatric neuroradiologist who was blinded to the Fio(2) level. The Wilcoxon signed rank test was used to determine if CSF hyperintensity was correlated with Fio(2). RESULTS: CSF hyperintensity was present in all 20 children (age range, 1.9-16.7 years; 12 children were boys) when the Fio(2) was 100%. The hyperintensity partially or completely disappeared in the basilar cisterns (P <.001) and cerebral sulcal subarachnoid space (P <.001) after Fio(2) was reduced from 100% to 30%. CONCLUSION: These findings are consistent with the hypothesis that increased arterial oxygen tension and consequently increased CSF Po(2) resulting from administration of high Fio(2) during general anesthesia are responsible for the increased CSF signal intensity noted on brain FLAIR MR images.

Practice of pediatric critical care medicine: results of the Future of Pediatric Education II survey of sections project.

OBJECTIVE: To summarize the demographics and practice patterns of the current pediatric critical care workforce and to identify the key workforce issues that may affect the delivery of pediatric critical care services in the future. DESIGN: A questionnaire designed to analyze current pediatric critical care workforce demographics and future workforce trends. SUBJECTS: Pediatric critical care physicians from the United States were identified from the American Academy of Pediatrics Critical Care Section, from a list of physicians certified in pediatric critical care medicine (PCCM) by the American Board of Pediatrics, and from a list of pediatrician members of the Society for Critical Care Medicine. INTERVENTIONS: None. MEASUREMENTS: PCCM physicians were polled regarding board certification, practice characteristics, professional activities, referral patterns, patient profiles, competition, job satisfaction, and projected retirement age. MAIN RESULTS: A total of 805 PCCM physicians completed the survey. When grouped by age, 40% of the responding PCCM physicians were younger than 40 yrs, 49% were 40 to 49 yrs old, and only 11% were 50 yrs of age or older. The younger group had a higher percentage of female pediatricians than the older groups. For all age groups, the largest proportion of time was devoted to direct patient care time in pediatric critical care. This was especially true for the youngest age group that had the largest amount of patient care time devoted to critical care (43%). Time devoted to research was also significantly higher for the younger age group, although very few respondents reported that they have >50% of their time protected for research. For all age groups, those reporting increases in referral volume and referral complexity over the previous 12 months far outnumbered those reporting decreases. The majority of respondents reported being satisfied with their career choice. In general, respondents were more likely to report that too many rather than too few PCCM physicians were currently being trained. Approximately one third of respondents (34%) planned on leaving the field of critical care medicine before retiring from medicine completely. CONCLUSIONS: PCCM physicians were increasingly women and working for >65 hrs/wk, with a good level of job satisfaction. Competition from a variety of sources seems to affect the work of PCCM physicians. The relatively small percentage of time devoted to research, however, is a finding of great concern.

Fraction of inspired oxygen in relation to cerebrospinal fluid hyperintensity on FLAIR MR imaging of the brain in children and young adults undergoing anesthesia.

OBJECTIVE: Cerebrospinal fluid (CSF) hyperintensity has been described on fluid-attenuated inversion recovery (FLAIR) imaging in anesthetized patients who underwent MR imaging without apparent subarachnoid abnormality. The purpose of our study was to delineate likely causes for this hyperintensity. Specifically, we sought to determine whether a high inspired oxygen fraction given as part of the anesthetic was responsible for the CSF hyperintensity seen on FLAIR imaging. MATERIALS AND METHODS: A retrospective study was conducted using anesthetic records and brain MR images of 70 children and young adults who had a FLAIR sequence while undergoing general anesthesia. Information about inspired oxygen fraction, oxygen saturation, and type of anesthetic agents preceding the FLAIR sequence was obtained from the anesthetic record. A pediatric neuroradiologist who was unaware of the inspired oxygen fraction and anesthetic agent ascertained the presence of CSF hyperintensity in the basilar cisterns and cerebral sulcal subarachnoid space. RESULTS: Twenty-one patients received an inspired oxygen fraction less than or equal to 0.60, and 49 received an inspired oxygen fraction greater than 0.60. Inspired oxygen fraction greater than 0.60 was significantly associated with the presence of CSF hyperintensity in the basilar cisterns (p < 0.001) and in the cerebral sulcal subarachnoid space (p = 0.03). The type of anesthetic agent, patient's sex, or status (based on the American Society of Anesthesiology physical status and classification system), and presence of cardiopulmonary disease or seizure disorder were not associated with CSF hyperintensity. CONCLUSION: High inspired oxygen fraction during anesthesia is associated with CSF hyperintensity in the basilar cisterns and the cerebral sulcal subarachnoid space on FLAIR imaging in children and young adults. Physicians should be aware of this finding to avoid misinterpreting this artifact as an abnormality.