Seeing through the blind! Ability of hospital staff to differentiate morphine from placebo, in neonates at a placebo controlled trial.

Aim: To investigate whether professional training and/or clinical experience affect the ability of caregiver to assess clinical signs of pre-emptive morphine analgesia.

Methods: In the Neurological Outcomes & Pre-emptive Analgesia In Neonates trial preterm infants undergoing mechanical ventilation were randomized to receive continuous infusion, either of morphine or placebo blinded. Staff from centres in Sweden (Stockholm and Orebro) completed an assessment form.

Results: A total of 360 assessment forms were collected from 52 neonates. In 59% of the cases, caregivers correctly identified patients group. Comparable proportion of answers were correct between physicians, nurses and assistant nurses (63, 60 and 54%, respectively, p = 0.60). Staff with Neonatal intensive care unit experience <1 year identified 63%, as compared to 65% for working 1-5 year, and 55% that has been working >5 years (p = 0.28). Staff's ability to correctly identify group assignment was reduced by amount of additional morphine (p < 0.01) and severity of illness (p = 0.01).

Conclusions: Clinical medical staffs, including neonatologists, have great difficulties in assessing the presence and severity of pain. Further studies should focus on the methods for assessment of prolonged pain in preterm neonates, define the effects of adequate analgesia, and investigate the clinical factors that may alter neonatal responses to acute and prolonged pain.