Gabapentin's safety and impact on benzodiazepine exposure post-superior cavopulmonary anastomosis

In paediatric cardiac patients requiring staged palliation, superior cavopulmonary anastomosis is common. Pain control is a crucial aspect of postoperative care as agitation, untreated pain, and hypoventilation can cause increased pulmonary vascular resistance reduction and pulmonary blood flow.

This was a large volume single-centre, retrospective cohort study evaluating the impact of gabapentin on opioid and benzodiazepine exposure in infants undergoing superior cavopulmonary anastomosis between January 2018 and December 2022. The primary endpoint was opioid exposure in morphine milligram equivalents per kilogram in infants receiving gabapentin compared to no gabapentin.

The study analysed 85 infants, 40 of which received perioperative gabapentin. Other than there being more males in the gabapentin group (70% versus 47%; p = 0.03), there was no difference in baseline characteristics. Opioid use, measured in morphine milligram equivalents per kilogram, was similar in the no gabapentin group compared to the gabapentin group during the first 5 POD's (2.66 (interquartile range1.76, 3.30) versus 2.27 (interquartile range R 1.75, 3.40); p = 0.93. However, there was a lower benzodiazepine exposure, measured in midazolam equivalents per kilogram, in the gabapentin group both on POD 2 (0.05 (interquartile range 0.00, 0.11) versus 0 (interquartile range 0.00, 0.08); p = 0.031) and cumulative (0.15 (interquartile range 0.00, 0.35) versus 0.05 (interquartile range 0.00, 0.15); p = 0.031).

Gabapentin did not significantly reduce opioid exposure; however, its use was associated with modest reduction in benzodiazepine exposure. There were no differences in adverse events. Our findings suggest gabapentin is safe in infants undergoing superior cavopulmonary anastomosis; however, additional studies should be conducted to evaluate optimal gabapentin dosing.