Pain study tests morphine for effectiveness on premature babies

By Julie Griffiths on 02 January 2019 Pain relief Research Premature Birth

Administration of oral morphine (100μg/kg) to non-ventilated premature infants has the potential for harm without analgesic effectiveness, a study concludes.

The study sought to find a solution to treating infant pain, which is undertreated because the small number of evidence-based analgesics. 

Although morphine is often used to sedate ventilated infants, its analgesic effect is unclear and the researchers aimed to establish whether oral morphine could provide effective and safe analgesia in non-ventilated premature infants for acute procedural pain.

The trial involved 31 infants at the John Radcliffe Hospital, Oxford. Eligible infants were born prematurely at less than 32 weeks' gestation or with a birthweight lower than 1501g and had a gestational age of 34 to 42 weeks at the time of the study. 

Between October 2016 and November 2017, 15 infants were randomly allocated to morphine and 16 to placebo, although one infant assigned placebo was withdrawn from the study before monitoring began.  

The allocation occurred before a clinically required heel lance and retinopathy of prematurity screening examination, on the same occasion. This examination is painful, stressful, and causes substantial physiological instability for 48 hours post procedure.

However, the predefined stopping boundary was crossed, and trial recruitment stopped because of profound respiratory adverse effects of morphine without suggestion of analgesic efficacy. 

The researchers have concluded that oral morphine for retinopathy of prematurity screening is not recommended and strongly advised caution if considering its use for other acute painful procedures in non-ventilated premature infants.

The study, published in The Lancet, can be read here.