Local anaesthetic eye drops for prevention of pain in preterm infants undergoing screening for retinopathy of prematurity

Abstract

Background: Screening examinations for retinopathy of prematurity (ROP) are performed routinely in the neonatal intensive care unit and are a recognised cause of pain in the newborn.

Objectives: To determine the effect of instillation of topical anaesthetic eye drops compared with placebo or no treatment on pain in infants undergoing ROP screening.

Search strategy: We used the standard search strategy of the Cochrane Neonatal Review Group. This included a search of the Cochrane Neonatal Group register and the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 10, 2010). We identified relevant studies by searching the following: (1) computerised bibliographic databases: MEDLINE (1966 to October 2010), EMBASE (1988 to October 2010) and Web of Science (1975 to March 2010; (2) the Oxford Database of Perinatal Trials. We searched electronically abstracts from PAS from 2000 to 2010 and handsearched abstracts from ESPR from 2000 to 2009.

Selection criteria: All randomised, or quasi-randomised controlled trials, or randomised cross-over trials.

Data collection and analysis: We used the standard methods of the Cochrane Neonatal Review Group.

Main results: We identified two studies for inclusion. Both studies were randomised cross-over trials performed in single centres. Both studies used the Premature Infant Pain Profile (PIPP) score as a measure of pain response. Different methods of evaluating PIPP scores are presented including the absolute PIPP score, a PIPP score > 10 or > 12 and an increase in PIPP ≥ 4 from the baseline value. There is a nonsignificant reduction in pain scores at one minute and a nonsignificant increase at five minutes post insertion of the speculum. PIPP score > 12 at one minute resulted in a statistically significant reduction in the number of patients who experienced pain (typical risk ratio (RR) 0.56, 95% CI 0.36 to 0.89; typical risk difference (RD) -0.23, 95% CI -0.39 to -0.86; number needed to treat to benefit (NNTB) 4). When pain was defined as an increase in PIPP > 4 there was a statistically significant reduction in the absolute number of patients who experienced pain at one minute (typical RR 0.70, 95% CI 0.52 to 0.94; typical RD -0.19, 95% CI -0.34 to -0.04; NNTB 5.3).

Authors' conclusions: The administration of topical proparacaine 30 seconds prior to the ophthalmological evaluation was associated with a reduction in pain scores especially at the time of speculum insertion. However, despite treatment, screening remains a painful procedure and the role of nonpharmacological and pharmacological intervention including different local anaesthetic agents should be ascertained in future randomised trials.

1.1. Analysis

Comparison 1 PIPP scores, Outcome 1 PIPP score prior to examination.

1.2. Analysis

Comparison 1 PIPP scores, Outcome 2 PIPP score at insertion of wire.

1.3. Analysis

Comparison 1 PIPP scores, Outcome 3 PIPP score 1 minute following examination.

1.4. Analysis

Comparison 1 PIPP scores, Outcome 4 PIPP score 5 minutes following examination.

1.5. Analysis

Comparison 1 PIPP scores, Outcome 5 Significant pain response PIPP > 10.

1.6. Analysis

Comparison 1 PIPP scores, Outcome 6 Significant pain response PIPP > 12 at 1 minute.

1.7. Analysis

Comparison 1 PIPP scores, Outcome 7 Significant pain response PIPP > 12 at 5 minutes.

1.8. Analysis

Comparison 1 PIPP scores, Outcome 8 Increase in PIPP score > 4 at 1 minute.

1.9. Analysis

Comparison 1 PIPP scores, Outcome 9 Increase in PIPP score > 4 at 5 minutes.

2.1. Analysis

Comparison 2 Oxygen desaturation >10%, Outcome 1 Oxygen desaturation >10% at speculum insertion.

2.2. Analysis

Comparison 2 Oxygen desaturation >10%, Outcome 2 Oxygen desaturation > 10% post examination.