In our series less than 30% of non-living donor paediatric KTs were performed during the ordinary working hours. However, no differences in terms of short-term outcomes were found among the patients treated in the ordinary day, in the day-off or at night-time. The overall rate of complications was also similar. Nevertheless, KTs performed during days-off presented a longer length of surgery and a higher risk of post-operative bleedings.
Despite the institutional well-standardized protocol for paediatric KTs, the study presented some limitations that mainly resided in the retrospective design of the study. First of all, the limited size of the population might have undermined the statistical significance of the results. Second, it was not possible to assess the surgeon’s working and stress load before the KT surgical performance. This might represent a crucial aspect for the main objective of the paper. Future studies dealing with surgeon’s fatigue before paediatric KTs should be encouraged. Finally, the accurate duration of bench surgery was missing in most cases. However, the number of vascular variants requiring a complex bench surgery was similar. This aspect did not affect the outcomes or the risk of adverse events, as previously reported [14].
The identification of potential risk factors for complications is crucial to improve both performance and outcome of paediatric KTs. The outcomes of KTs performed not among regular working hours has been already investigated in the adult population. A systematic review and meta-analysis did not find an increased hazard for the KTs performed after-hours [15] and, more recently, two pilot studies found that night-time KT did not present an increased risk of complications [6, 7]. Nevertheless, paediatric KTs might be more challenging for the surgeons, especially those performed in low-weight children or in presence of complex somatic and vascular malformations [3]. For this reason, the cutting time or the calendar might be relevant and might increase the rate of adverse events.
Our rate of after-hours KTs was considerably high and might be explained by several aspects such as logistic. Indeed, the KT was frequently delayed after the ongoing elective surgery because no operating rooms were available. Moreover, KT was started immediately after a negative crossmatch testing was available, in order to reduce the length of the CIT, that represents one of the main factors influencing the recovery of the allograft [8]. For this reason, our current policy is to avoid delays for the performance of KTs.
More than two thirds of the KTs in our series were started between 5.00 and 9.00 PM. The surgeons might have just finished their ordinary activity without resting before entering on-call shift for KTs. This can certainly lead to sleep deprivation and fatigue [16]. Consequently, surgeon’s performance might be diminished, raising the risk of complications. It has been proved that sleep deprivation, fatigue, and stress due to the workload increase the risk of human error and prolong the surgical times for procedures that require concentration and caution [17]. Nevertheless, night-time KTs presented a reduced operative time, since the main operator could be more fatigued, willing to end earlier the intervention. On the other hand, KTs performed during days-off presented a longer length of surgery probably due to the fatigue accumulated during the previous ordinary working days.
Furthermore, most of the documented complications were concentrated in the span of time between 5.00 and 9.00 PM or at the end of the night-time. Once again, sleep deprivation might have influenced this outcome. It is relevant to report that caffeine consumption after sleep deprivation did not influence fine motor skills that are crucial for vascular anastomosis [18].
The analysis of our data found no difference in terms of overall complications and short-terms outcomes among the groups. These results were consistent with the findings in the adult’s population [6, 7]. It is relevant to report that the occurrence of post-operative bleedings was higher in KTs performed during days-off. This might be a warning sign of fatigue. The successful endpoints might be due to a standardization of the surgical procedure and post-operative management together with a well-trained multidisciplinary team, including surgeons, anaesthesiologists, nephrologists, and nurses [19].
Moreover, another innovative device could be considered to improve the outcomes of paediatric KTs. The hypothermic machine perfusion of the allografts showed promising results in the adult population [20]. This technology might help the planification of paediatric KTs and, consequently, to reduce the risk of adverse events due to surgeons’ fatigue.