BACKGROUND: Interindividual variability in pain perception and analgesic response is a major problem in perioperative practice. Adult studies suggest pain management is influenced by patient’s race. The objective of this study is to evaluate the influence of race on perioperative pain treatment in children. METHODS: Prospective observational study evaluating effect of race on analgesia and opioid related adverse effects after tonsillectomy in African American and Caucasian children. A sample of 194 healthy children between 6 and 15 years of age were included. Race was self-identified by parents. All participants received standard perioperative care with a standard anesthetic and an intraoperative dose of morphine. Analgesia outcomes included maximum postoperative pain scores, postoperative opioid requirement, and analgesic interventions. Safety outcomes included incidences of opioid related adverse effects. RESULTS: African American children experienced significantly more postoperative pain than Caucasian children as measured by postoperative opioid requirement (P = .0011), maximum postoperative pain scores (P < .0001), and analgesic interventions (P < .0001) in the recovery room. Although Caucasian children received relatively less opioids perioperatively, they had significantly higher opioid related adverse effects (P = .039). African American children with obstructive sleep apnea were more likely to have prolonged post anesthesia recovery unit stay due to inadequate pain control. CONCLUSIONS: After similar uses of intraoperative morphine for tonsillectomy, there was an unequal burden of increased pain in African American children and increased opioid adverse effects in Caucasian children in the recovery room. Though Caucasian children received relatively less opioids perioperatively, they had higher incidences of opioid related adverse effects than African American children.

Aim Large interindividual variability in morphine disposition could contribute to unpredictable variability in morphine analgesia and adverse events. Caucasian children have more adverse effects and slower morphine clearance than African–American children. To study variations in intravenous morphine pharmacokinetics in children, we examined the influence of genetic polymorphisms in OCT1 Methods In 146 children undergoing adenotonsillectomy, 146 concentration–time profiles (2–4 measurements per patient) were available. Population pharmacokinetic ana lysis characterized the profiles in NONMEM® and tested OCT1 variants as covariates. Results Allometrically scaled post hoc Bayesian morphine clearance in homozygotes of loss-of-function OCT1 variants (n = 9, OCT1*2–*5/*2–*5 was significantly lower (20%) than in wild-type (n = 85, OCT1*1/*1) and heterozygotes (n = 52, OCT1*1/*2–*5; p < 0.05). Conclusion Besides bodyweight, OCT1 genotypes play a significant role in intravenous morphine pharmacokinetics. Relatively high allelic frequencies of defective OCT1 variants among Caucasians may explain their lower morphine clearance and possibly higher frequencies of adverse events compared with African–American children.

Objectives: The main objectives of this study were to prospectively evaluate the safety and efficacy of stereotactic body radiation therapy (SBRT) in the neoadjuvant setting for resectable or borderline resectable pancreatic cancer. Materials and Methods: Eighteen patients were enrolled from November 2014 to June 2017. Following 3 cycles of chemotherapy, SBRT was delivered to the tumor and abutting vessel and a 3 mm planning target volume (PTV) margin to 33 Gy (6.6 Gy×5) with an optional elective PTV to 25 Gy (5 Gy×5) customized to the nodal space and mesenteric vessels. The primary endpoint is ≥grade 3 acute and late gastrointestinal toxicity. Results: Fifteen patients had borderline resectable tumors due to arterial abutment (n=7) or superior mesenteric vein encasement (n=8); 3 patients had resectable tumors. There were no ≥grade 3 acute or late gastrointestinal events. Following SBRT, surgery was performed in 12 patients (67%) with 11 (92%) R0 resections. The median overall survival and progression-free survival was 21 months (95% CI: 18-29) and 11 months (95% CI: 8.4-16). Progression occurred in 83% (10/12) of resected patients (distant [n=4, 40%], local-only [n=4, 40%], and local and distant [n=2, 20%]). The cumulative incidence of local failure (LF) at 12 months from resection was 50% (95% CI: 20-80). All LF were outside to the PTV33. Conclusions: Neoadjuvant SBRT was well tolerated, however LFs were predominantly observed outside the PTV33 volume that would have been covered with conventional RT volumes. The durability of local control after SBRT in the neoadjuvant setting merits examination relative to chemoradiation before incorporation into routine practice.

Background Effective perioperative analgesia is lacking for children owing to interindividual variations and underdosing of opioids caused by fear of adverse effects. We investigated the role of COMT SNPs on postoperative pain management in children. Methods One hundred and forty nine children undergoing adenotonsillectomy were enrolled. The associations of four COMT SNPs (rs6269, rs4633, rs4818 and rs4680) with postoperative pain were analyzed and outcome measures included maximum pain scores, need for postoperative opioid interventions and postoperative morphine requirements. Results We detected an association of postoperative opioid intervention need with all four COMT SNPs. Minor allele carriers of COMT SNPs were approximately three-times more likely to require analgesic interventions than homozygotes of major alleles (p-value range: 0.0031–0.0127; odds ratio range: 2.6–3.1). In addition, significant association was detected between maximum Face, Leg, Activity, Consolability, Cry (FLACC) pain scores and three COMT SNPs (rs6269, rs4633 and rs4680). Haplotype 1 (ATCA: 51.3%) and Haplotype 2 (GCGG: 36.2%) are more frequent. Haplotype 2 was associated with higher odds of intravenous analgesic intervention need in postanesthesia recovery unit with an odds ratio of 2.6 (95% CI: 1.2–5.4; p-value = 0.022). Conclusion COMT SNPs may play a significant role in interindividual variation in postoperative pain perception and postoperative morphine requirements in children.

Opioid-related respiratory depression (RD) is a serious clinical problem as it causes multiple deaths and anoxic brain injuries. Morphine is subject to efflux via P-glycoprotein transporter encoded by ABCB1, also known as MDR1. ABCB1 polymorphisms may affect blood-brain barrier transport of morphine and therefore individual response to its central analgesic and adverse effects. This study aimed to determine specific associations between common ABCB1 genetic variants and clinically important outcomes including RD and RD resulting in prolonged stay in hospital with intravenous morphine in a homogenous pediatric surgical pain population of 263 children undergoing tonsillectomy. Children with GG and GA genotypes of ABCB1 polymorphism rs9282564 had higher risks of RD resulting in prolonged hospital stays; adding one copy of the minor allele (G) increased the odds of prolonged hospital stay due to postoperative RD by 4.7-fold (95% confidence interval: 2.1-10.8, P=0.0002).