TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractMany heavy oil and oil sand reservoirs are in communication with water sand(s). Depending on the density ( o API gravity) of oil, the water sand could lie above or below the oil zone. Steamflooding a heavy oil or oil sand reservoir with a contiguous water sand (water which may lie below or above the oil-bearing zone) is risky due to the possibility of short circuiting the steam chamber.

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Background Inhaled nitrous oxide (N2O) is a potentially effective agent for pain and procedural distress in children but questions remain regarding indication specific effectiveness. Objectives Our objective was to synthesize the evidence for N2O in children and youth regarding procedural distress, pain, and adverse events (AEs). Design/Methods We performed electronic searches of MEDLINE, EMBASE, Google Scholar, CINAHL, conference proceedings, and trial registries. We included randomized trials of N2O in children and youth 0-21.99 years that reported procedural distress or pain. Methodological rigor and quality of evidence were evaluated using the Cochrane Collaboration’s Risk of Bias tool and the Grading of Recommendations Assessment, Development, and Evaluation system, respectively. Where meta-analysis wasn’t possible, we summarized results using Tricco et al.’s classification system of “favorable” or “unfavorable” (p<0.05), or “neutral” (p>0.05). Results We included 29 trials, involving 2,404 children aged 3 weeks-21 years. The overall quality of evidence for distress and pain was “low” and “moderate”, respectively. For venous cannulation (n=12), three meta-analyses were possible: A) pain was significantly lower with 70% N2O versus eutectic mixture of local anesthetics (EMLA) (mean difference: -16.5; 95% CI: -28.6 to -4.4; p=0.008; 85 participants; 3 trials; I2= 0%); B) pain was not significantly different with 50% N2O alone versus EMLA (mean difference: -0.4; 95% CI: -1.2 to 0.3; p=0.26; 65 participants; 2 trials; I2= 15%); C) combination 50% N2O plus EMLA was significantly better than EMLA alone (mean difference: -1.2; 95% CI: -2.1 to -0.3; p=0.007; 65 participants; 2 trials; I2= 43%). For pain and distress during laceration repair (n=5), N2O was deemed “favorable” versus subcutaneous lidocaine, oxygen, or oral midazolam, but “neutral” versus intravenous ketamine. For pain and distress during fracture reduction (n=3), N2O was deemed “neutral” versus combination intramuscular meperidine plus promethazine, intravenous lidocaine, or combination intravenous ketamine plus midazolam. For pain and distress during lumbar puncture (n=1), N2O was deemed “favorable” versus oxygen. Higher concentrations of N20 were associated with more AEs per participant: 6.7% (1/15), 13.7% (64/468), and 25.3% (56/221) with 30%, 50%, and 70% N2O, respectively. The most common AEs were nausea and agitation (both 3.5% [40/1128]). There were no AEs requiring resuscitative measures. Conclusion N2O is a potentially effective agent for reducing procedural distress and pain in children, although high quality evidence is lacking. Most data exist for venous cannulation where safety and efficacy at reducing pain are optimized with combining 50% N2O and topical anesthetic cream. For laceration repair, there is considerably less data. Still, N2O appears to be superior to oral midazolam but equivalent to intravenous ketamine.

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Background Ileocolic intussusception requires timely reduction to prevent complications. Reduction can be distressing. Sedation is uncommon due to controversial beliefs surrounding an increased risk of perforation. Analgesia and sedation practices for children undergoing reduction of intussusception remain largely unknown. Objectives To characterize global practice patterns of analgesia and sedation for reduction of intussusception. Design/Methods We conducted a global, cross-sectional study involving 84 centres in 14 countries. We included children 4 to 48 months with a sonographic or radiographic diagnosis of ileocolic intussusception and attempted reduction between January 1, 2017, and December 31, 2019. The primary and secondary outcomes were analgesia and sedation, respectively, prior to reduction. An a priori explanatory analysis was performed to explore the association of sedation with (i) adverse events, (ii) perforation, and (iii) failed reduction. Results We included 3203 children [2054/3203 (64.1%)] males, with median (IQR) age of 17 (9,27) months. Suspected abdominal pain was present in 2283/3187 (71.6%) children. At triage, a pain assessment tool was documented in 1859/3112 (59.7%) and analgesia was administered to 305/3171 (9.6%) children. After triage, pain was reassessed in 1448/3169 (45.7%) and analgesia was administered to 552/3158 (17.5%) children. Prior to reduction, 550/3161 (17.4%) children were sedated. Non-opioid and opioid analgesia were administered to 183/2945 (6.2%) and 560/3134 (17.9%), respectively. Reduction was performed using air enema in 2372/3184 (74.5%) children and 2700/3184 (84.8%) of all reductions were successful. Reduction related adverse events [65/3166 (2.1%)] were reported in 59 patients, most commonly vomiting [31/3166 (1.0%)] and perforation [13/3166 (0.4%)]. In the bivariate analyses, sedation was not associated with an increased odds of adverse events [OR: 1.1; 95% CI: 0.6-2.1; p=0.79] or perforation [OR: 2.1; 95% CI: 0.7-6.9; p=0.21]. Sedation was associated with an increased odds of failed reduction [OR: 1.4; 95% CI: 1.1-1.7; p=0.01], but this became non-significant in the multivariable analysis [OR: 1.1; 95% CI: 0.8-1.6; p=0.53] after adjusting for age and premorbid gastrointestinal anomaly. Conclusion Although more than 2/3 of children with intussusception present with pain, less than 10% were administered analgesia at triage. Prior to reduction, analgesia or sedation was administered to less than 1/5 of children. Adverse events, including perforation were uncommon. Sedation was not associated with adverse events or an increased odds of failed reduction in the adjusted analysis. Our findings suggest that analgesia should be considered in children with suspected abdominal pain and sedation should be routinely considered for children undergoing reduction of intussusception.