A prospective study of phrenic nerve damage after cardiac surgery in children.

OBJECTIVE

To gather detailed data on the incidence of phrenic nerve damage (PND) following cardiac surgery in children, the risk factors for its development, its effect on morbidity and its prognosis.

DESIGN

Prospective electrophysiological measurement of phrenic nerve latency in 310 children before and after cardiac surgery.

SETTING

Tertiary paediatric cardiac surgical centre.

MEASUREMENTS AND RESULTS

Our findings were fourfold. Firstly, the incidence of PND in our group of patients was 20%, significantly higher than estimates using indirect methods of assessment. Secondly, PND increased the duration of ventilation by a median of 76 h (20 vs. 96 h; p<0.001), and late post-operative deaths (before hospital discharge) occurred in 12.9% of patients compared to 2.4% among patients with a normal post-operative phrenic latency. Thirdly, the risk factors that were independently predictive of the development of PND were the site of the surgery and the patient's age. Patients who required surgery at both the lung hilum and the pericardium were more likely to develop PND than patients with only one of those sites, or when neither was involved, and children less than 18 months old were more likely to develop PND than older children. Lastly, the natural history of PND following surgery appears to be good. In our follow-up to 3 months, approximately one third recovered within 1 month and a further third (overall) recovered by 3 months.

CONCLUSIONS

We conclude that the incidence of PND is much higher than currently recognised, and has a very significant effect on post-operative morbidity and mortality. Most children who survive the post-operative period will recover nerve function within 3 months.