Perioperative Regional Anesthesia Pain Outcomes in Children: A Retrospective Study of 3160 Regional Anesthetics in Routine Practice.

OBJECTIVE: Randomized controlled trials indicate regional anesthesia (RA) improves postoperative outcomes with reduced pain and opioid consumption. Therefore, we hypothesized children who received RA, regardless of technique, would have reduced pain/opioid use in routine practice. METHODS: Using a retrospective cohort, we assessed the association of RA with perioperative outcomes in everyday practice at our academic pediatric hospital. Patients 18 years or below undergoing orthopedic, urologic, or general surgeries with and without RA from May 2014 to September 2021 were categorized as single shot, catheter based, or no block. Outcomes included intraoperative opioid exposure and dose, preincision anesthesia time, postanesthesia care unit (PACU) opioid exposure and dose, PACU antiemetic/antipruritic administration, PACU/inpatient pain scores, PACU/inpatient lengths of stay, and cumulative opioid exposure. Regression models estimated the adjusted association of RA with outcomes, controlling for multiple variables. RESULTS: A total of 11,292 procedures with 3160 RAs were included. Compared with no-block group, single-shot and catheter-based blocks were associated with opioid-free intraoperative anesthesia and opioid-free PACU stays. Post-PACU (ie, while inpatient), single-shot blocks were not associated with improved pain scores or reduced opioid use. Catheter-based blocks were associated with reduced PACU and inpatient opioid use until 24 hours postop, no difference in opioid use from 24 to 36 hours, and a higher probability of use from 36 to 72 hours. RA was not associated with reduced cumulative opioid consumption. DISCUSSION: Despite adjustment for confounders, the association of RA with pediatric pain/opioid use outcomes was mixed. Further investigation is necessary to maximize the benefits of RA.

The association of intraoperative opioid dose with postanesthesia care unit outcomes in children: a retrospective study.

PURPOSE: In children, the relationship between the dose of intraoperative opioid and postoperative outcomes is unclear. We examined the relationship between intraoperative opioid dose and postanesthesia care unit (PACU) pain scores and opioid and antiemetic administrations. METHODS: We performed a single-institution retrospective cohort study. Patients who were aged < 19 yr, had an American Society of Anesthesiologists Physical Status of I-III, were undergoing one of 11 procedures under general anesthesia and without regional anesthesia, and who were admitted to the PACU were included. Patients were analyzed by quartiles of total intraoperative opioid dose using multivariable regression, adjusting for confounders including procedure. An exploratory analysis of opioid-free anesthetics was also performed. RESULTS: Three thousand, seven hundred and thirty-three cases were included, and the mean age of included patients was 8.3 yr. After adjustment, there were no significant differences between the lowest and higher quartiles for first conscious pain score, mean pain score, PACU opioid dose, or PACU length of stay; in addition, estimated differences were small. Patients in higher quartiles were estimated to be more likely to receive antiemetics, significantly so for those in the second quartile. Patients in the lowest quartile received significantly more intraoperative nonopioid analgesics. In the exploratory analysis, no significant difference in PACU pain scores was found in cases without intraoperative opioids. CONCLUSIONS: Children who received lower doses of intraoperative opioids did not have worse PACU pain outcomes but required fewer antiemetics and received greater numbers of nonopioid analgesics intraoperatively. These findings suggest that lower doses of intraoperative opioids may be administered to children as long as other analgesics are used.

RéSUMé: OBJECTIF: Chez les enfants, la relation entre la dose peropératoire d'opioïdes et les issues postopératoires n'est pas claire. Nous avons examiné la relation entre la dose peropératoire d'opioïdes, les scores de douleur en salle de réveil, et les administrations d'opioïdes et d'antiémétiques. MéTHODE: Nous avons réalisé une étude de cohorte rétrospective dans un seul établissement. Nous avons inclus les patient·es âgé·es < 19 ans ayant un statut physique ASA de I-III et bénéficiant de l'une de 11 interventions sous anesthésie générale et sans anesthésie régionale, et qui avaient été admis·es en salle de réveil. Les patient·es ont été analysé·es par quartiles de la dose totale d'opioïdes peropératoires en utilisant une régression multivariée, en ajustant les données pour tenir compte des facteurs de confusion, notamment de l'intervention. Une analyse exploratoire des anesthésiques sans opioïdes a également été réalisée. RéSULTATS: Au total 3733 cas ont été inclus, et l'âge moyen des enfants était de 8,3 ans. Après ajustement, il n'y avait pas de différences significatives entre les quartiles inférieur et supérieur pour le premier score de douleur chez l'enfant conscient·e, le score de douleur moyen, la dose d'opioïdes en salle de réveil ou la durée du séjour en salle de réveil; de plus, les différences estimées étaient faibles. On a estimé que les patient·es des quartiles supérieurs étaient plus susceptibles de recevoir des antiémétiques et ce, de manière significative pour ceux et celles du deuxième quartile. Les patient·es du quartile inférieur ont reçu significativement plus d'analgésiques non opioïdes peropératoires. Dans l'analyse exploratoire, aucune différence significative dans les scores de douleur en salle de réveil n'a été trouvée dans les cas sans opioïdes peropératoires. CONCLUSION: Les enfants qui ont reçu des doses plus faibles d'opioïdes peropératoires n'ont pas eu de pires issues de douleur en salle de réveil, mais ont eu besoin de moins d'antiémétiques et ont reçu un plus grand nombre d'analgésiques non opioïdes en peropératoire. Ces résultats suggèrent que des doses plus faibles d'opioïdes peropératoires peuvent être administrées aux enfants tant que d'autres analgésiques sont utilisés.

Pain Prevalence and Treatment in Hospitalized Children and Adolescents at a US Tertiary Pediatric Hospital.

Poorly controlled acute pain is associated with worsened patient outcomes. Prior studies suggest that acute pain is a common complaint among hospitalized pediatric patients, but recent studies with substantial numbers of patients from US hospitals are lacking. We retrospectively reviewed inpatients at a single academic children's hospital during twelve 24-hour periods in 2021. Outcomes were assessed for patients on non-intensive care unit (ICU) inpatient floors and in ICUs. The primary outcome was any presence of moderate to severe pain. Of 1355 patients on a non-ICU inpatient floor and 485 patients in the ICU, 23.5% and 58.6%, respectively, had ≥1 moderate to severe pain score during the 24-hour analysis period. While the mean pain score was low for the majority of patients, moderate to severe pain is frequent in hospitalized children. Future studies may focus on identification of variables associated with pediatric inpatients at risk of moderate to severe pain as well as improved pain prevention and reduction strategies.

Racial/Ethnic Variability in Use of General Anesthesia for Pediatric Magnetic Resonance Imaging.

BACKGROUND: Children increasingly undergo diagnostic imaging procedures, sometimes with general anesthesia (GA). It is unknown whether the use of GA differs by race/ethnicity among children undergoing magnetic resonance imaging (MRI) scans. METHODS: This is a retrospective cohort study of GA use for pediatric patients from 0 to 21 years of age who underwent MRIs from January 1, 2004 to May 31, 2019. The study sample was stratified into 5 age groups: 0 to 1, 2 to 5, 6 to 11, 12 to 18, and 19 to 21. Analysis was performed separately for each age group. RESULTS: Among 457,314 MRI patients, 29,108 (6.4%) had GA. In the adjusted regression models, Asian patients aged 0 to 1 (adjusted relative risk [aRR] [95% confidence interval {CI}] of 1.11 [1.05-1.17], P < .001) and aged 2 to 5 (aRR [95% CI], 1.04 [1.00-1.09], P = .03), Black patients aged 2 to 5 (aRR [95% CI], 1.04 [1.01-1.08], P = .02) and aged 6 to 11 (aRR [95% CI], 1.13 [1.06-1.20], P < .001), and Hispanic patients aged 0 to 1 (aRR [95% CI], 1.07 [1.03-1.12], P < .001) were more likely to receive GA for MRIs than White patients. CONCLUSIONS: Asian, Black, and Hispanic children of some ages were more likely to receive GA during MRI scans than White children in the same age group. Future research is warranted to delineate whether this phenomenon signifies disparate care for children based on their race/ethnicity.

Association of Race and Ethnicity with Pediatric Postoperative Pain Outcomes.

INTRODUCTION: Inequitable variability in healthcare practice negatively affects patient outcomes. Children of color may receive different analgesic medications in the perioperative period, resulting in different outcomes. METHODS: Medical records of children 0 to ≤ 18 years old from May 2014 to August 2019 were reviewed. The exposure was racial or ethnic groups: Asian, Black, Hispanic, Pacific Islander, and White non-Hispanic (reference). PRIMARY OUTCOME: post-anesthesia care unit mean pain score. SECONDARY OUTCOMES: inpatient mean pain score; opioid, antiemetic, and antipruritic administration in the post-anesthesia care unit and inpatient ward. The association of race or ethnicity with outcomes was modeled using multilevel logistic regression, adjusting for confounders and covariates. RESULTS: Twenty-nine thousand six hundred fourteen cases are included. In the post-anesthesia care unit, Black, Hispanic, and Pacific Islander children had no significant difference in the odds of receiving opioids or having moderate-severe pain as compared to White non-Hispanic patients; Asian children had lower odds of receiving opioids and lower odds of having a moderate-severe mean pain score. In the inpatient setting, Black, Hispanic, and Pacific Islander children had no significant difference in the odds of receiving opioids or having moderate severe-pain as compared to White non-Hispanic children, but Asian children had lower odds of receiving opioids and of having a moderate-severe mean pain score. CONCLUSIONS: Asian children had lower odds of receiving opioids and having moderate-severe pain postoperatively compared to the White non-Hispanic children. These differences may be a function of variation in patient/caregivers culture or healthcare provider care and warrant further investigation.

Health Care Burden Associated With Adolescent Prolonged Opioid Use After Surgery.

BACKGROUND: Prolonged opioid use after surgery (POUS), defined as the filling of at least 1 opioid prescription filled between 90 and 180 days after surgery, has been shown to increase health care costs and utilization in adult populations. However, its economic burden has not been studied in adolescent patients. We hypothesized that adolescents with POUS would have higher health care costs and utilization than non-POUS patients. METHODS: Opioid-naive patients 12 to 21 years of age in the United States who received outpatient prescription opioids after surgery were identified from insurance claim data from the Optum Clinformatics Data Mart Database from January 1, 2003, to June 30, 2019. The primary outcomes were total health care costs and visits in the 730-day period after the surgical encounter in patients with POUS versus those without POUS. Multivariable regression analyses were used to determine adjusted health care cost and visit differences. RESULTS: A total of 126,338 unique patients undergoing 132,107 procedures were included in the analysis, with 4867 patients meeting criteria for POUS for an incidence of 3.9%. Adjusted mean total health care costs in the 730 days after surgery were $4604 (95% confidence interval [CI], $4027-$5181) higher in patients with POUS than that in non-POUS patients. Patients with POUS had increases in mean adjusted inpatient length of stay (0.26 greater [95% CI, 0.22-0.30]), inpatient visits (0.07 greater [95% CI, 0.07-0.08]), emergency visits (0.96 greater [95% CI, 0.89-1.03]), and outpatient/other visits (5.78 greater [95% CI, 5.37-6.19]) in the 730 days after surgery ( P < .001 for all comparisons). CONCLUSIONS: In adolescents, POUS was associated with increased total health care costs and utilization in the 730 days after their surgical encounter. Given the increased health care burden associated with POUS in adolescents, further investigation of preventative measures for high-risk individuals and additional study of the relationship between opioid prescription and outcomes may be warranted.

Association of Common Pediatric Surgeries With New Onset Chronic Pain in Patients 0-21 Years of Age in the United States.

Chronic pain (CP) is a major public health issue. While new onset CP is known to occur frequently after some pediatric surgeries, its incidence after the most common pediatric surgeries is unknown. This retrospective cohort study used insurance claims data from 2002 to 2017 for patients 0 to 21 years of age. The primary outcome was CP 90 to 365 days after each of the 20 most frequent surgeries in 5 age categories (identified using CP ICD codes). Multivariable logistic regression identified surgeries and risk factors associated with CP after surgery. A total of 424,590 surgical patients aged 0 to 21 were included, 22,361 of whom developed CP in the 90 to 365 days after surgery. The incidences of CP after surgery were: 1.1% in age group 0 to 1 years; 3.0% in 2 to 5 years; 5.6% in 6 to 11 years; 10.1% in 12 to 18 years; 9.9% in 19 to 21 years. Some surgeries and patient variables were associated with CP. Approximately 1 in 10 adolescents who underwent the most common surgeries developed CP, as did a striking percentage of children in other age groups. Given the long-term consequences of CP, resources should be allocated toward identification of high-risk pediatric patients and strategies to prevent CP after surgery. PERSPECTIVE: This study identifies the incidences of and risk factors for chronic pain after common surgeries in patients 0 to 21 years of age. Our findings suggest that resources should be allocated toward the identification of high-risk pediatric patients and strategies to prevent CP after surgery.

Enhanced recovery after cleft palate repair: A quality improvement project.

BACKGROUND: Children undergoing cleft palate repair present challenges to postoperative management due to several factors that can complicate recovery. Utilization of multimodal analgesic protocols can improve outcomes in this population. We report experience designing and implementing an enhanced recovery after surgery (ERAS) pathway for cleft palate repair to optimize postoperative recovery. AIMS: The primary aim was to implement an ERAS pathway with >70% bundle adherence to achieve a 30% reduction in postoperative opioid consumption within 12 months. Our secondary aims assessed intraoperative opioid consumption, length of stay, timeliness of oral intake, and respiratory recovery. METHODS: A multidisciplinary team of perioperative providers developed an ERAS pathway for cleft palate patients. Key drivers included patient and provider education, formal pathway creation and implementation, multimodal pain therapy, and target-based care. Interventions included maxillary nerve blockade and enhanced intra- and postoperative medication regimens. Outcomes were displayed as statistical process control charts. RESULTS: Pathway compliance was 77.0%. Patients during the intervention period (n = 39) experienced a 49% reduction in postoperative opioid consumption (p < .0001) relative to our historical cohort (n = 63), with a mean difference of -0.33 ± 0.11 mg/kg (95% CI -0.55 to -0.12 mg/kg). Intraoperative opioid consumption was reduced by 36% (p = .002), with a mean difference of -0.27 ± 0.09 mg/kg (95% CI -0.45 to -0.09 mg/kg). Additionally, patients in the intervention group had a 45% reduction in time to first oral intake (p = .02) relative to our historical cohort, with a mean difference of -3.81 ± 1.56 h (95% CI -6.9 to -0.70). There was no difference in PACU or hospital length of stay, but there was a significant reduction in variance of all secondary outcomes. CONCLUSION: Opioid reduction and improved timeliness of oral intake is possible with an ERAS protocol for cleft palate repair, but our protocol did not alter PACU or hospital length of stay.

Pediatric chronic post-surgical pain prevalence, pain scores, and quality-of-life: results of an exploratory patient survey at a single-center tertiary care children's hospital.

PURPOSE: Twenty percent of children may develop chronic post-surgical pain (CPSP), but studies investigating pediatric CPSP are limited in scope. In an exploratory patient survey, we sought to assess CPSP prevalence among children of all ages, across a wide range of surgeries, and over an extended period of time after surgery. METHODS: We conducted a survey study, including patients < 19 years of age at the time of their surgery at a single-center, quaternary care academic pediatric hospital. Pediatric patients who underwent surgery from May 2014 to August 2019 were included. Via electronic survey, patients/caregivers were asked whether the child had any pain related to their last surgery at the pediatric hospital. Patients/caregivers who answered yes were asked 11 additional questions about the child's pain and pain-related quality of life. The primary outcome was CPSP prevalence; secondary outcomes were pain scores, quality-of-life scores, and the associations of CPSP with time since surgery, preoperative pain, and patient age. RESULTS: The response rate of completed surveys was 4.0%. 30% of respondents reported CPSP; the median pain score was 4.0 on an 11 point scale (0 to 10). Responses to quality of life questions indicated CPSP negatively impacted many children's lives. Preoperative pain was associated with an odds ratio for CPSP of 1.09 [95% confidence interval (CI): 0.58, 2.04], each year after surgery with an odds ratio of 0.94 (95% CI 0.80, 1.10), and each year of age at surgery with an odds ratio of 1.07 (95% CI 1.02, 1.12). CONCLUSION: While limited by a low response rate, results from this exploratory survey suggest that CPSP is a considerable problem for children who undergo surgery across many specialties, with marked effects on patient well-being even years after surgery.

Prediction of Prolonged Opioid Use After Surgery in Adolescents: Insights From Machine Learning.

BACKGROUND: Long-term opioid use has negative health care consequences. Patients who undergo surgery are at risk for prolonged opioid use after surgery (POUS). While risk factors have been previously identified, no methods currently exist to determine higher-risk patients. We assessed the ability of a variety of machine-learning algorithms to predict adolescents at risk of POUS and to identify factors associated with this risk. METHODS: A retrospective cohort study was conducted using a national insurance claims database of adolescents aged 12-21 years who underwent 1 of 1297 surgeries, with general anesthesia, from January 1, 2011 to December 30, 2017. Logistic regression with an L2 penalty and with a logistic regression with an L1 lasso (Lasso) penalty, random forests, gradient boosting machines, and extreme gradient boosted models were trained using patient and provider characteristics to predict POUS (≥1 opioid prescription fill within 90-180 days after surgery) risk. Predictive capabilities were assessed using the area under the receiver-operating characteristic curve (AUC)/C-statistic, mean average precision (MAP); individual decision thresholds were compared using sensitivity, specificity, Youden Index, F1 score, and number needed to evaluate. The variables most strongly associated with POUS risk were identified using permutation importance. RESULTS: Of 186,493 eligible patient surgical visits, 8410 (4.51%) had POUS. The top-performing algorithm achieved an overall AUC of 0.711 (95% confidence interval [CI], 0.699-0.723) and significantly higher AUCs for certain surgeries (eg, 0.823 for spinal fusion surgery and 0.812 for dental surgery). The variables with the strongest association with POUS were the days' supply of opioids and oral morphine milligram equivalents of opioids in the year before surgery. CONCLUSIONS: Machine-learning models to predict POUS risk among adolescents show modest to strong results for different surgeries and reveal variables associated with higher risk. These results may inform health care system-specific identification of patients at higher risk for POUS and drive development of preventative measures.

Association Between Race and Ethnicity with Intraoperative Analgesic Administration and Initial Recovery Room Pain Scores in Pediatric Patients: a Single-Center Study of 21,229 Surgeries.

INTRODUCTION: Perioperative pain may have deleterious effects for all patients. We aim to examine disparities in pain management for children in the perioperative period to understand whether any racial and ethnic groups are at increased risk of poor pain control. METHODS: Medical records from children ≤ 18 years of age who underwent surgery from May 2014 to May 2018 were reviewed. The primary outcome was total intraoperative morphine equivalents. The secondary outcomes were intraoperative non-opioid analgesic administration and first conscious pain score. The exposure was race and ethnicity. The associations of race and ethnicity with outcomes of interest were modeled using linear or logistic regression, adjusted for preselected confounders and covariates. Bonferroni corrections were made for multiple comparisons. RESULTS: A total of 21,229 anesthetics were included in analyses. In the adjusted analysis, no racial and ethnic group received significantly more or less opioids intraoperatively than non-Hispanic (NH) whites. Asians, Hispanics, and Pacific Islanders were estimated to have significantly lower odds of receiving non-opioid analgesics than NH whites: odds ratio (OR) = 0.83 (95% confidence interval (CI): 0.70, 0.97); OR = 0.84 (95% CI: 0.74, 0.97), and OR = 0.53 (95% CI: 0.33, 0.84) respectively. Asians were estimated to have significantly lower odds of reporting moderate-to-severe pain on awakening than NH whites: OR = 0.80 (95% CI: 0.66, 0.99). CONCLUSIONS: Although children of all races and ethnicities investigated received similar total intraoperative opioid doses, some were less likely to receive non-opioid analgesics intraoperatively. Asians were less likely to report moderate-severe pain upon awakening. Further investigation may delineate how these differences lead to disparate patient outcomes and are influenced by patient, provider, and system factors.

Incidence of and Factors Associated With Prolonged and Persistent Postoperative Opioid Use in Children 0-18 Years of Age.

BACKGROUND: Long-term opioid use has negative health care consequences. Opioid-naïve adults are at risk for prolonged and persistent opioid use after surgery. While these outcomes have been examined in some adolescent and teenage populations, little is known about the risk of prolonged and persistent postoperative opioid use after common surgeries compared to children who do not undergo surgery and factors associated with these issues among pediatric surgical patients of all ages. METHODS: Using a national administrative claims database, we identified 175,878 surgical visits by opioid-naïve children aged ≤18 years who underwent ≥1 of the 20 most common surgeries from each of 4 age groups between December 31, 2002, and December 30, 2017, and who filled a perioperative opioid prescription 30 days before to 14 days after surgery. Prolonged opioid use after surgery (filling ≥1 opioid prescription 90-180 days after surgery) was compared to a reference sample of 1,354,909 nonsurgical patients randomly assigned a false "surgery" date. Multivariable logistic regression models were used to estimate the association of surgical procedures and 22 other variables of interest with prolonged opioid use and persistent postoperative opioid use (filling ≥60 days' supply of opioids 90-365 days after surgery) for each age group. RESULTS: Prolonged opioid use after surgery occurred in 0.77%, 0.76%, 1.00%, and 3.80% of surgical patients ages 0-<2, 2-<6, 6-<12, and 12-18, respectively. It was significantly more common in surgical patients than in nonsurgical patients (ages 0-<2: odds ratio [OR] = 4.6 [95% confidence interval (CI), 3.7-5.6]; ages 2-<6: OR = 2.5 [95% CI, 2.1-2.8]; ages 6-<12: OR = 2.1 [95% CI, 1.9-2.4]; and ages 12-18: OR = 1.8 [95% CI, 1.7-1.9]). In the multivariable models for ages 0-<12 years, few surgical procedures and none of the other variables of interest were associated with prolonged opioid use. In the models for ages 12-18 years, 10 surgical procedures and 5 other variables of interest were associated with prolonged opioid use. Persistent postoperative opioid use occurred in <0.1% of patients in all age groups. CONCLUSIONS: Some patient characteristics and surgeries are positively and negatively associated with prolonged opioid use in opioid-naïve children of all ages, but persistent opioid use is rare. Specific pediatric subpopulations (eg, older patients with a history of mood/personality disorder or chronic pain) may be at markedly higher risk.

Association Between Race and Ethnicity in the Delivery of Regional Anesthesia for Pediatric Patients: A Single-Center Study of 3189 Regional Anesthetics in 25,664 Surgeries.

BACKGROUND: Racial and ethnic disparities in health care are well documented in the United States, although evidence of disparities in pediatric anesthesia is limited. We sought to determine whether there is an association between race and ethnicity and the use of intraoperative regional anesthesia at a single academic children's hospital. METHODS: We performed a retrospective review of all anesthetics at an academic tertiary children's hospital between May 4, 2014, and May 31, 2018. The primary outcome was delivery of regional anesthesia, defined as a neuraxial or peripheral nerve block. The association between patient race and ethnicity (white non-Hispanic or minority) and receipt of regional anesthesia was assessed using multivariable logistic regression. Sensitivity analyses were performed comparing white non-Hispanic to an expansion of the single minority group to individual racial and ethnic groups and on patients undergoing surgeries most likely to receive regional anesthesia (orthopedic and urology patients). RESULTS: Of 33,713 patient cases eligible for inclusion, 25,664 met criteria for analysis. Three-thousand one-hundred eighty-nine patients (12.4%) received regional anesthesia. One thousand eighty-six of 8884 (13.3%) white non-Hispanic patients and 2003 of 16,780 (11.9%) minority patients received regional anesthesia. After multivariable adjustment for confounding, race and ethnicity were not found to be significantly associated with receiving intraoperative regional anesthesia (adjusted odds ratios [ORs] = 0.95; 95% confidence interval [CI], 0.86-1.06; P = .36). Sensitivity analyses did not find significant differences between the white non-Hispanic group and individual races and ethnicities, nor did they find significant differences when analyzing only orthopedic and urology patients, despite observing some meaningful clinical differences. CONCLUSIONS: In an analysis of patients undergoing surgical anesthesia at a single academic children's hospital, race and ethnicity were not significantly associated with the adjusted ORs of receiving intraoperative regional anesthesia. This finding contrasts with much of the existing health care disparities literature and warrants further study with additional datasets to understand the mechanisms involved.

Virtual reality during pediatric vascular access: A pragmatic, prospective randomized, controlled trial.

BACKGROUND: Vascular access is a minor procedure that is associated with reported pain and fear in pediatric patients, often resulting in procedural incompliance. Virtual reality has been shown to be effective in adult populations for reducing pain and anxiety in various medical settings, although large studies are lacking in pediatrics. AIMS: The primary aim was to determine whether pain would be reduced in pediatric patients using virtual reality undergoing vascular access. The four secondary aims measured patient fear, procedural compliance, satisfaction, and adverse events. METHODS: A prospective, randomized, controlled trial was completed at a pediatric hospital, enrolling children 7-18 years old undergoing vascular access in a variety of clinical settings, randomized to virtual reality or standard of care. Pain scores were measured using a numeric pain faces scale. The secondary outcomes of patient fear, procedural compliance, satisfaction, and adverse events were measured with the Child Fear Scale, modified Induction Compliance Checklist, and satisfaction surveys, respectively. Chi-squared, t tests, and regression models were used to analyze the results. RESULTS: The analysis included 106 patients in the virtual reality group and 114 in the control. There were no significant differences in postprocedure pain (VR group estimated 0.11 points lower, 95% confidence interval: 0.50 points lower to 0.28 points greater, P = .59), postprocedure fear (VR group estimated 0.05 points lower, 95% confidence interval: 0.23 points lower to 0.13 points greater), or compliance (adjusted odds ratio 2.31, 95% confidence interval: 0.96-5.56). Children in the virtual reality group were satisfied with the intervention. There were no adverse events. CONCLUSION: This study demonstrates no reduction in pain while using Virtual reality (VR) across a heterogeneous pediatric inpatient population undergoing vascular access.

Anisotropic growth of water-puckered pentamers on a mica terrace.

Ice nucleation at mica terrace edges in air forms mounds of water molecules that grow larger as the step-edge height increases from a few Angstroms to hundreds of nanometers. The structures of the ice deposits at mica terrace edges were characterized by atomic force microscopy (AFM), and the edges were shown to act as nucleators for water pentamers, thereby forming a zigzag structure with lattice parameters of 0.72 ± 0.07 and 0.60 ± 0.06 nm. A three-dimensional arrangement of three pentamers of water molecules, which formed a parasol-like structure, was assembled to match the AFM images. Seven three-fused pentamers were clustered to form large hexamers that cover the entire surface. The nucleation at the edges reveals a substantially larger growth rate than that on the mica terraces; consequently, highly terraced mica slabs could be used as new and more efficient structures for seeding clouds and causing rain. On the basis of this finding, a new ice-condensation structure was designed with pyramidal features and steps of 100 nm in height and width.

Drainage kinetics of nanochannels fabricated in water films a few molecules thick on mica at room temperature.

Nanochannels of the order of 20 nm in diameter and forming arrangements that were a few micrometres wide were fabricated on nanometre-thick ice-like deposits on planar mica surfaces at room temperature. Because an atomic force microscopy tip can write lines on ice-like layers covering mica substrates in air that are stable under invariant conditions of humidity and temperature, the water films were modulated with nanochannels. By analysing the shape and morphology of the material removed after channel fabrication for various time intervals, the channel profile was shown to vary with a scale of a tenth of a second. In this configuration (hydrophobic tip and hydrophilic substrate, 65% RH), at the channel top region there were only aggregates of loose flakes formed after the film inscription but no liquid. Apparently, the Kelvin effect is responsible for the nanochannel profile variation with time, but the calculated and measured values of the drainage time constant are at variance by six orders of magnitude. This reduction of the mass transfer is associated with the small dimensions of the ∼ 10 nm-wide channels.

Long nanofibers arrays through surfactant self-assembly.

Self assembly of molecules can be a simple and versatile approach that may lead to nanostructures. Here we report the formation of arrangements of exceptionally long nanofibers of cationic surfactant hexadecyltrimethylammonium bromide molecules with highly defined spatial and parallel ordering. Arrangements of approximately 1 microm long nanofibers were observed by non-contact atomic force microscopy. The long nanofiber patterns form structures in approximately 5 x 5 microm2 regions and consist of approximately 6 nm wide lines. The formation mechanism of the fibers is shown to be the coalescence of isolated surfactant micelles (approximately 3.2 nm diameter in solution) in the convection stream of the surfactant solution drop close to the pinned contact-line region during drying. The size of micelles formed in solution determines the diameter of the deposited fibers. New deposition schemes of micelles forming nanorods on bare silicon previous to the formation of surfactant bilayers are now being investigated based on the data obtained in this work.