Introduction: Peri-operative respiratory adverse events remain a major cause of morbidity and mortality in children undergoing general anaesthesia; those with asthma are at higher risk. The aim of this feasibility study was to determine whether pre-operative measurements of fractional exhaled nitric oxide and the forced oscillation technique are feasible in children, and to explore whether these measurements can predict peri-operative respiratory adverse events.
Methods: We assigned children into respiratory or control groups, according to the presence or absence of respiratory symptoms. We recorded pre-operative measurements of fractional exhaled nitric oxide as well as respiratory mechanics, as determined by the forced oscillation technique. We then recorded the incidence of peri-operative respiratory adverse events.
Results: We enrolled 120 children of which 116 were included. Fractional exhaled nitric oxide and respiratory mechanics (forced oscillation technique) were recorded in 106/116 (91%) and 71/116 (61%), respectively. Peri-operative respiratory adverse events occurred in 17/116 (15%) patients but there was no difference between groups (OR 2.11, 95%CI 0.74-6.55). Pre-operative fractional exhaled nitric oxide levels did not predict the occurrence of peri-operative respiratory adverse events. The measurement of respiratory mechanics using the forced oscillation technique did not predict peri-operative respiratory adverse events.
Discussion: We have shown the feasibility of study enrolment and pre-operative fractional exhaled nitric oxide measurement but had difficulty obtaining measurements of respiratory mechanics (forced oscillation technique). Neither test improved the prediction of peri-operative respiratory adverse events reliably in this group of patients. A thorough pre-operative clinical history combined with care by an experienced paediatric anaesthetist remains the most reliable means of reducing peri-operative respiratory adverse events.
Keywords: anaesthesia; asthma; paediatric; paediatric anaesthesia; peri‐operative respiratory adverse events.
Breathing problems during and after an operation can sometimes make children very sick. These problems happen more often in children with asthma. In this study, we wanted to see if two special breathing tests could help doctors find out which children might have breathing problems during an operation. The two tests were called the fractional exhaled nitric oxide test and the forced oscillation technique. We put the children into two groups: one group had breathing symptoms (like coughing or wheezing) and the other group did not. Before their operations, we measured their breathing using the two tests. Then, we kept track of any breathing problems they had during or after their operation. We started with 120 children, and 116 were part of the final study. We were able to do the first test (the nitric oxide test) in 91% of the children and the second test (the oscillation test) in 61% of them. About 15% of the children (17 out of 116) had breathing problems around the time of their operation. However, there was no big difference between the two groups. The breathing tests did not help us predict which children would have breathing problems. We found that it was possible to do the study and use the nitric oxide test before the operation, but the oscillation test was harder to do. Neither test helped doctors tell which children might have breathing problems. The best way to keep children safe is still for doctors to take a careful medical history and for experienced children's anaesthetists to look after them during the operation.
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