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Notes: A rapid gas chromatographic method is described for the simultaneous determination of glycerol, sorbitol or mannitol in a variety of raw materials or finished products.The method is based upon the direct conversion, normally without predrying, of sample humectants into their acetate derivatives by bomb reaction with acetic anhydride in the presence of pentaerythritol added as internal standard. The resultant acetates are determined by g.l.c.; a complete determination requires about 30 min. The method, as described, is not applicable to samples containing borax or boric acid derivatives. Le dosage d'humectants par chromatographie en phase gazeus

Notes: Summary Sixty-two children were randomly allocated to receive, during inhalational anaesthesia with isoflurane and nitrous oxide, either 1.0 µg.kg−1 remifentanil (n = 33) or saline (n = 29) just before the tunnelling phase of ventriculoperitoneal shunt insertion, in a double-blind study. The remifentanil group showed little stress response to tunnelling as indicated by median (interquartile range [range]) change in heart rate −5.2 (−11.4 to 9.8 [−19.4 to 30.4])%, mean arterial pressure −5.0 (−20.8 to 15.5 [−40.9 to 42.9])% or plasma norepinephrine −13.5 (−38.1 to −2.5 [−77.7 to 81.5])% compared with the saline group, in which the changes were 20.1 (11.5–36.1 [2.1–83.1])%, 42.7 (27.1–56.8 [3.2–73.5])% and 13.3 (0.8–70.0 [−45.2 to 337.5])%, respectively (p 〈 0.001 for all comparisons). These changes were consistent across most different age categories. The cardiovascular response in the saline group lasted for 8 (4–15 [0–39]) min. Tracheal extubation occurred after 3 (2–4 [1–8]) min in the remifentanil group and 3 (2–6␣[0–15]) min in the saline group (p = 0.29), with transfer to the recovery area and discharge to␣the ward, respectively, 4 (4–5 [1–10]) min and 9 (7–13 [2–32]) min in the remifentanil group and 7␣(4–8 [2–18]) min and 14 (10–19 [7–44]) min in the saline group (p = 0.06 and 0.01, respectively). Postoperatively there was some evidence of respiratory depression and increased oxygen requirements in all age categories, but this was similar in both groups. Overall, the maximum increase from baseline in transcutaneous carbon dioxide tension was 41.2 (11.3–66.7 [−2.0 to 141.7])% in the remifentanil group compared with 30.7 (20.5–55.1 [1.7–159])% in the saline group (p = 0.8), and the time taken for transcutaneous carbon dioxide tension to decrease to 〈 6.0 kPa was 4 (0–13 [0–60]) min compared with 7 (0–13 [0–60]) min, respectively (p = 0.75). There was no difference between the two groups in postoperative analgesic requirements or in blood loss and there were no significant side-effects. We conclude that remifentanil is an appropriate and safe analgesic to provide balanced␣anaesthesia to cover the tunnelling phase of paediatric ventriculoperitoneal shunt insertion.