Alfentanil as procedural pain relief in newborn infants.

AIMS: To assess the need for, and the suitability of, alfentanil for pain relief during tracheal suction used in assisted ventilation in newborn infants. METHODS: In a randomised, controlled, double blind, crossover trial, placebo (10 micrograms/kg) and 20 micrograms/kg alfentanil were infused in random order two minutes before three separate endotracheal suctions, at least six hours apart, to 10 infants. Measurements were made of physiological variables, behaviour, and stress hormones. RESULTS: After placebo infusion heart rate significantly increased (median 14; interquartile range 12-16 beats/minute) as did behavioural pain score (5; 3-5). Alfentanil (20 micrograms/kg) attenuated the heart rate increase, normalised the pain score, and caused a decrease in plasma adrenaline activity (0.3; 0.2-0.7 nmol/l). Noradrenaline concentration showed a nonsignificant decreasing trend with increasing alfentanil dose and beta endorphin was unchanged. Rigidity was noted in the placebo (n = 2), 10 micrograms/kg (n = 2), and 20 micrograms/kg (n = 5) alfentanil groups, respectively. CONCLUSIONS: Tracheal suction is a painful procedure. The dose of alfentanil required for pain relief (20 micrograms/kg) causes a high incidence of rigidity and thus should be used only with muscle relaxant.