4. Discussion
Our findings suggest that closed-PICU perioperative management by pediatric intensivists results in a significant increase in the 28-day VFD and reduction in the length of postoperative PICU stay of CTS patients.
The median 28-day VFD was longer in the closed-PICU group than in the open-PICU group. This is likely to be attributable to the changes in the preoperative and postoperative respiratory management policies. The introduction of the sedation scale may have contributed to this result. In terms of preoperative respiratory management, more patients in the open-PICU group were intubated until surgery. Fewer patients underwent preoperative mechanical ventilatory management in the closed-PICU group due to inclusion of cases transferred from other hospitals, in whom extubation was difficult. However, they were successfully extubated in our hospital, thus allowing management in the PICU without a mechanical ventilator until surgery. In the closed-PICU group, we achieved a shortened duration of postoperative muscle relaxant administration by controlling the degree of sedation stringently using a newly introduced sedation scale. We also worked aggressively to ensure the use of appropriate ventilatory support devices to reduce the effort of breathing after extubation. These devices were used in 89% of patients in the closed-PICU group compared to only 39% of patients in the open-PICU group. In the perioperative management of CTS, we assumed that ventilator-induced diaphragmatic dysfunction10,11 was always present due to long-term preoperative mechanical ventilatory management, diaphragmatic immobilization secondary to postoperative use of muscle relaxants, and increased airway resistance due to postoperative tracheal edema. Furthermore, the increased respiratory rate and secretions due to crying increased the relative airway resistance, thereby resulting in an increase in respiratory effort. Sedation management was essential in preventing crying; however, the difficulties encountered in the removal of secretions due to over-sedation could have resulted in ventilation failure. These changes in perioperative respiratory management, including the introduction of a sedation scale and early rehabilitation, may have been the reasons behind the increase in the 28-VFD of the closed-PICU group.
The length of postoperative PICU stay was significantly shorter in the closed-PICU group. A prolonged PICU stay increases the risk for delirium in children12; hence, shortening ICU stay is beneficial to patients and may help curb their hospitalization costs. The presence of a pediatric intensivist in the PICU was associated with lower patient mortality, duration of mechanical ventilation, length of PICU stay, and hospital-acquired infections7. Additionally, a 24-hour shift of pediatric intensivists in the PICU are associated with reduction the duration of mechanical ventilation and length of ICU stay as compared with a 12-hour shift13. Our study corroborated the finding that the 24-hour shift of pediatric intensivists reduced the length of postoperative PICU stay. One possible explanation is the improved adherence to guidelines by the intensivists14. The guidelines of the European Society of Intensive Care Medicine15 recommend early initiation of enteral feeding in patients with controlled hypoxemia, hypercapnia, and acidosis. Furthermore, the guidelines also recommend against delays in the initiation of nutrition when using muscle relaxants. In this study, enteral feeding was started earlier in the closed-PICU group, suggesting that pediatric intensivists may have been managing patients in compliance with the guidelines.
Additionally, we trained the teams in resuscitation and ECMO trouble-shooting simulations to respond to emergency situations better. Perioperative management of CTS patients by a multidisciplinary team significantly reduces the length of PICU stay, thereby reducing the cost of treatment16. In this study, CPR events occurred in 10% of the patients after CTS surgery. This suggested the importance of creating teams that were well trained in emergency response procedures such as extracorporeal cardiopulmonary resuscitation (ECPR). One case in each group of our study required postoperative ECPR; the patient in the open-PICU group died, whereas the one in the closed-PICU group survived. For conditions like CTS, where multiple professionals are involved and postoperative management or care is complex, management by a multidisciplinary team may have led to a shorter PICU stay. The mortality rate in our study (2%) is comparable with those seen in previous reports (5–13%)17-19. Furthermore, our results are comparable to those of a previous report by Butler et al.20, which has the largest study sample (n=101). There were no deaths in the closed-PICU group, suggesting that our team was well trained and well equipped in responding to sudden events adverse such as postoperative ventilation failure and cardiac arrest.
CTS is a rare disease, and only a few large-scale studies have been published20,21. These studies have mainly evaluated surgical management, but, to the best of our knowledge, only one report16 focused on perioperative management. Only a few studies have demonstrated the benefits of being managed by a pediatric intensivist. These studies have studied heterogeneous populations because the target population has included all patients admitted to the PICU7,13. This study, to the best of our knowledge, is the first to observe the impact of pediatric intensivists on patient outcomes in a relatively large and homogeneous population despite the rare prevalence of CTS.
This study had some limitations. First, the sample size was small, and there were missing data in the open-PICU group. Nosocomial infections such as ventilator-associated pneumonia were important factors affecting patient outcomes; however, surveillance was not available in the open-PICU group. Additionally, data on detailed ventilator settings were not available in the medical records. The second limitation is the pre–post comparison design of this study. Changes in intraoperative management and improvement in surgical techniques have resulted in shortened duration of mechanical ventilation management and decreased mortality20,22. However, we attempted to minimize the impact of changes over time by limiting the study to patients undergoing slide tracheoplasty and by only including cases that had undergone surgery in the year prior to the change in PICU management in the open-PICU group. Finally, there was a lack of patient matching by severity of illness. Preoperative ECMO management20, low body weight, and younger age21 have been reported to be risk factors for death. Preoperative ECMO management was not performed in either group, and there were no significant differences in weight and age. The number of patients who had been intubated until surgery was significantly higher in the open-PICU group than in the closed-PICU group. This was probably related to the change in attempting extubation and enabling the growth of the patients until better operative conditions, as far as could be safely achieved, were available. In addition, details regarding bronchial morphology, such as the difference between the left and right bronchial diameters (bronchial mismatch)23 and surgical technique24, were not analyzed.
Additionally, the presence of confounding factors cannot be excluded due to the retrospective design of the study. Future prospective studies with more participants are recommended to overcome these limitations.