Dosage regimens for inhaled therapy in children should be reconsidered.

In current asthma guidelines, dosage regimens for inhalation therapy in children are based on adult doses and are generally titrated per kilogram of bodyweight or per square metre of body surface area. However, these recommendations do not correspond well with current knowledge of aerosol therapy in childhood. Lung deposition of the aerosolised drug is the key determinant for clinical efficacy and for systemic side effects of inhalation therapy. Lung deposition increases with age, whereas lung deposition expressed as a percentage per kilogram bodyweight is age-independent. This finding is explained by the self-regulating effect of age-dependent airway anatomy on lung deposition. Therefore, it is more likely that adult doses translate into paediatric doses only by virtue of the differences in self-limiting pulmonary deposition when using the same absolute nominal doses of the medication. Adapting the adult dose to a paediatric dose calculated on body size might be unnecessary and could lead to insufficient pulmonary deposition of medication. These findings suggest that dosage regimens for inhalation therapy for children may have to be reconsidered, and should be determined from dose-ranging studies rather than calculated from adult doses based on body size.

The effects of sevoflurane and halothane anesthesia on cerebral blood flow velocity in children.

UNLABELLED: We compared cerebral blood flow velocity during anesthesia with sevoflurane and halothane in 23 children admitted for elective surgery (age, 0.4-9.7 yr; median age, 1.9 yr; ASA physical status I-II). Inhaled induction was performed in a randomized sequence with sevoflurane or halothane. Under steady-state conditions, cerebral blood flow velocity (systolic [V(s)], mean [V(mn)], and diastolic [VD]) were measured by a blinded investigator using transcranial pulsed Doppler ultrasonography. The anesthetic was then changed. CBFV measurements were repeated after washout of the first anesthetic and after steady-state of the second (equivalent minimal alveolar concentration to first anesthetic). The resistance index was calculated. VD and V(mn) were significantly lower during sevoflurane (V(mn) 1.35 m/s) than during halothane (V(mn) 1.50 m/s; P = 0.001), whereas V(s) was unchanged. The resistance index was lower during halothane (P < 0.001). Our results indicate lower vessel resistance and higher mean velocity during halothane than during sevoflurane. IMPLICATIONS: The mean cerebral blood flow velocity is significantly decreased in children during inhaled anesthesia with sevoflurane than during halothane. This might be relevant for the choice of anesthetic in children with risk of increased intracranial pressure, neurosurgery, or craniofacial osteotomies.

[Study of the protective action of nedocromil sodium with bronchial cold-air provocation in children with bronchial asthma]. / Untersuchung der protektiven Wirkung von Nedocromil-Natrium mit bronchialen Kaltluftprovokationen bei Kindern mit Asthma bronchiale.

12 children with known bronchial hyperreactivity and asthma had isocapnic cold air hyperventilation challenges of their bronchial airways. In a double-blind cross-over study they inhaled either placebo or nedocromil sodium (2 puffs à 2 mg) from a MDI before challenge. 2 subjects were found to be non-responders during the two days of the study. The remainder all reacted on the placebo days, while 5 subjects were completely protected on the nedocromil-days and 5 subjects were partially protected. Nedocromil is a potent agent for the suppression of bronchial hyperresponsiveness.