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Selected AbstractsThe ontogeny of diurnal rhythmicity in bed-sharing and solitary-sleeping infants: a preliminary report,INFANT AND CHILD DEVELOPMENT, Issue 4 2007Melissa M. Burnham Abstract The purpose of the current study was to investigate the development of sleep,wake and melatonin diurnal rhythms over the first 3 months of life, and the potential effect of bed-sharing on their development. It was hypothesized that increased maternal contact through bed-sharing would affect the development of rhythms in human infants. Ten solitary-sleeping and 8 bed-sharing infants' sleep,wake patterns and melatonin secretion were examined for 72 h at 1 and 3 months of age in their homes. Infants wore actigraphs on their ankles to study sleep,wake patterns. 6-Sulphatoxymelatonin was obtained through urine extracted from each diaper used over the 72-h study period. No significant differences were apparent in the timing of appearance or magnitude of sleep,wake or melatonin rhythms between bed-sharing and solitary-sleeping infants. Sleep,wake results were in the expected direction, with bed-sharing infants displaying more robust rhythms. A large degree of individual variability was evident in both rhythms, especially at 1 month. Three infants' parents regularly used a bright light source at night for feedings and diaper changes; the rhythms of these infants were less robust than the rest of the sample. Trends were mostly in the hypothesized direction and deserve attempts at replication with a larger sample. Copyright © 2007 John Wiley & Sons, Ltd. [source] A Scandinavian survey of drug administration through inhalation, suctioning and recruitment maneuvers in mechanically ventilated patientsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2009C. GRIVANS Background: The aim was to describe current practices for drug administration through inhalation, endotracheal suctioning and lung recruitment maneuvers in mechanically ventilated patients in Scandinavian intensive care units (ICUs). Methods: We invited 161 ICUs to participate in a web-based survey regarding (1) their routine standards and (2) current treatment of ventilated patients during the past 24 h. In order to characterize the patients, the lowest PaO2 with the corresponding highest FiO2, and the highest PaO2 with the corresponding lowest FiO2 during the 24-h study period were recorded. Results: Eighty-seven ICUs answered and reported 186 patients. Positive end-expiratory pressure (PEEP) levels (cmH2O) were 5,9 in 65% and >10 in 31% of the patients. Forty percent of the patients had heated humidification and 50% received inhalation of drugs. Endotracheal suctioning was performed >7 times during the study period in 40% of the patients, of which 23% had closed suction systems. Twenty percent of the patients underwent recruitment maneuvers. The most common recruitment maneuver was to increase PEEP and gradually increase the inspiratory pressure. Twenty-six percent of the calculated PaO2/FiO2 ratios varied >13 kPa for the same patient. Conclusion: Frequent use of drug administration through inhalation and endotracheal suctioning predispose to derecruitment of the lungs, possibly resulting in the large variations in PaO2/FiO2 ratios observed during the 24-h study period. Recruitment maneuvers were performed only in one-fifth of the patients during the day of the survey. [source] Pharmacokinetics and analgesic effects of intravenous propacetamol vs rectal paracetamol in children after major craniofacial surgeryPEDIATRIC ANESTHESIA, Issue 7 2008SANDRA A. PRINS MD PhD Summary Background:, The pharmacokinetics and analgesic effects of intravenous and rectal paracetamol were compared in nonventilated infants after craniofacial surgery in a double-blind placebo controlled study. Methods:, During surgery all infants (6 months,2 years) received a rectal loading dose of 40 mg·kg,1 paracetamol 2 h before anticipated extubation. On admittance to the pediatric surgical ICU, the children were randomized to receive either a 15 min intravenous infusion of 40 mg·kg,1 propacetamol, a prodrug of paracetamol, or 20 mg·kg,1 paracetamol rectally every 6 h. A population pharmacokinetic analysis of the paracetamol plasma concentration time-profiles was undertaken using nonlinear mixed effects models. The visual analogue scale (VAS) (score 0,10 cm) and COMFORT Behavior scale (score 6,30) were used to monitor analgesia in the 24-h period following surgery. Results:, Twelve infants received intravenous propacetamol and 14 paracetamol suppositories. Paracetamol pharmacokinetics were described according to a two-compartmental model with linear disposition. Pharmacokinetic parameters were standardized to a 70 kg person using allometric ,1/4 power' models. Parameter estimates were: absorption half-life from the rectum 4.6 h, propacetamol hydrolysis half-life 0.028 h, clearance 12 l·h,1·70 kg,1, intercompartmental clearance 116 l·h,1·70 kg,1, central and peripheral volume of distribution 7.9 and 44 l·70 kg,1, respectively. During the 24-h study period 22 infants exhibited VAS scores <4 cm, which was considered a cutoff point. On single occasions four patients, two in each group, exhibited a VAS score ,4 cm. Nine patients in the rectal treatment group and three patients in the intravenous treatment group received midazolam for COMFORT-B scores exceeding 17 (P < 0.05). Conclusions:, Intravenous propacetamol proved to be more effective than rectal paracetamol in infants after craniofacial surgery. Midazolam was more frequently administered to patients receiving paracetamol suppositories, indicating that these children experienced more distress, possibly caused by pain. [source] Development of a novel HPLC-MS/MS method for the determination of aconitine and its application to in vitro and rat microdialysis samplesBIOMEDICAL CHROMATOGRAPHY, Issue 7 2009Quan-long Zhang Abstract A sensitive and selective LC-MS/MS method was developed and validated for the determination of aconitine in microdialysate and rat plasma. Extraction of plasma sample was conducted by use of 1% trichloracetic acid and acetonitrile solution with 10 ng/mL internal standard (propafenone) spiked. Microdialysates were analyzed without sample purification. After sample preparation, 2 µL were injected and separated with an isocratic mobile phase consisting of acetonitrile:0.1% formic acid (60:40, v/v) at a flow rate of 0.3 mL/min. The Agilent G6410A triple quadrupole LC/MS system was operated under the multiple-reaction monitoring mode (MRM) using the electrospray ionization technique in positive mode. Overall, the assay exhibited good precision and accuracy. The diffusion properties of aconitine investigated in in vitro microdialysis experiments revealed unfavourable concentration dependence avertable by keeping a constant pH 5.77 using isotonic phosphate buffer solution as perfusate. The mean relative recoveries were 48.23% [coefficient of variation (CV 4.47%)] and 55.38% (CV 2.89%) for retrodialysis and recovery experiments, respectively. The in vivo recovery of aconitine was 34.48% (CV 3.05%) and was stable over the 6 h study period. Following characterization of aconitine both in vitro and in vivo microdialysis, the developed setting is suitable for application in pharmacokinetics and pharmacodynamics studies. Copyright © 2009 John Wiley & Sons, Ltd. [source] The circulating IGF system and its relationship with 24-h glucose regulation and insulin sensitivity in healthy subjectsCLINICAL ENDOCRINOLOGY, Issue 6 2003Jan Frystyk Summary objective and design It has been suggested that circulating free IGF-I participates in glucose homeostasis and that IGFBP-1 reflects changes in insulin sensitivity. To study this further, we examined 10 healthy, nonobese subjects under standardized conditions for 24 h with and without an intravenous infusion of glucose, the latter in order to augment insulin sensitivity. Serum was collected every 2 h for analysis of free and total IGFs, IGFBP-1, , 2 and , 3 and the acid labile subunit (ALS). Insulin sensitivity was estimated at the end of each 24-h study period by use of the hyperinsulinaemic euglycaemic clamp technique. results Glucose infusion resulted in mild hyperglycaemia (P < 0·0001), a reduction in IGFBP-1 by approximately 40% (P < 0·0003), and increased insulin and C-peptide levels (P < 0·0001). Glucose infusion also increased insulin sensitivity (P < 0·003). However, despite the reduction in IGFBP-1, glucose infusion did not increase free IGF-I over the control level, and free IGF-II was slightly reduced (P < 0·02). Irrespective of glucose infusion, free IGF-I and -II remained stable during daytime (i.e. they were unresponsive to meal-related changes in plasma glucose), but both free fractions decreased during the night, reaching nadir at 04·00 h. None of the other members of the IGF system showed any relationship with plasma glucose levels. Finally, we failed to observe any relationship between changes in insulin sensitivity and the circulating IGF system. conclusion We found no evidence that the circulating IGF system is involved in meal-related blood glucose regulation or that it reflects short-term changes in insulin sensitivity in healthy, nonobese subjects. However, we cannot preclude that the observed changes in circulating IGFBP-1 may affect the glucose-lowering effect of IGF-I and -II at the local tissue level. [source] | ||||||||||