ABSTRACT
In a minority of children after cardiovascular surgery may require prolonged mechanical ventilatory support and tracheostomy. We aim to describe indications, timing and, outcomes of the tracheostomy.
A retrospective review of 12 children requiring tracheostomy after cardiac surgery between January 2010-December 2019 was performed. The patients’ characteristics, indications and timing for tracheostomy, and survival were reviewed.
After cardiac surgery, 12 (0.5%) of 2.459 patients with a median age at surgery of 210 days (interquartile range: 75-262 days) underwent tracheostomy. The median time between cardiac surgery and tracheostomy was 25 days (interquartile range: 15-47 days). Diaphragmatic paralysis was the most common (42%) indication for tracheostomy. Genetic syndrome or at least one non-cardiac morbidity was present in 41.6% of patients. The duration of mechanical ventilation was shorter in patients who had tracheostomy within 30 days compared with >30 days following intubation (30 vs. 60 days, p=0.035). The median length of pediatric intensive care unit stays after the tracheostomy was 41 days (range, 21-289 days). Among all patients with congenital heart surgery undergoing tracheostomy, 6 (50%) of 12 were decannulated after a median time of 179 days (range, 34-463 days). The operative mortality was 8.3% (1/12) and the overall mortality during the first year of follow-up was 8.3% (1/12).
An early tracheostomy procedure may facilitates the weaning process and shorten the duration of positive pressure ventilation.
Keywords: Tracheostomy, congenital heart surgery, prolonged mechanical ventilation, children
Introduction
In the recent 20 years, improvement in the field of congenital heart surgery (CHS) and postoperative management result in improved survival in patients with congenital heart disease. Early extubation has advantages including reduced sedo-analgesia, decreased ventilator-associated pneumonia, and improved cardiovascular interactions. However, a small percentage of children who had CHS has a risk for prolonged ventilation. Prolonged mechanical ventilation is the most common indication for tracheostomy after CHS and occurs as a result of multiple etiologic factors. A large cohort of the patients who underwent tracheostomy after CHS reported that the incidence of tracheostomy increased from 0.11% to 0.76% between 2000-2012.1
Tracheostomy after cardiac operations appears to be associated with higher hospital mortality and higher mortality after discharge. Especially, children with single-ventricle physiology have lower long-term survival.2 After CHS, in-hospital mortality following tracheostomy ranged from 7.7% to 28%.3 However, the annual mortality rate of children with tracheostomy after CHS has not changed over time. It has reported 24.5% in 2010 and 27.5% in 2013.1
The purpose of the study is to describe the tracheostomy indications, complications, and long-term outcomes in children undergoing CHS.
Materials and Methods
We performed a retrospective chart review of all children who required tracheostomy after CHS from January 2010 to December 2019. Patients were identified from the pediatric intensive care unit (PICU) and cardiothoracic surgical database. All pediatric patients under the age of 14 years who underwent tracheostomy after CHS were included. Neonates and patients with tracheostomies placed before cardiac surgery were excluded. The demographic data, cardiac diagnosis, details of surgical procedures such as cross-clamp and cardiopulmonary bypass duration, and Risk Adjustment for Congenital Heart Surgery Score (RACHS)-1 were recorded.4 Patients were evaluated for several extubation trials, tracheostomy timing, and duration of mechanical ventilation before and after the tracheostomy. We also recorded the Pediatric Risk of Mortality Score (PRISM)-III at PICU admission, which is a validated and physiology-based scoring system for rating the severity of medical illness for children.5 The number of ventilator-associated pneumonia (VAP) episodes was recorded before and after tracheostomy. The indication for tracheostomy and, complications related to tracheostomy were recorded. This study was approved by the institutional review boards with the permission for the use of patient data for publication purposes (21-1T/26). Informed consent was received from the families.
Our primary outcomes included operative mortality and long-term survival, which was defined as 1-year survival. We reported operative mortality according to the definition of the Society of Thoracic Surgeons (STS) and Congenital Heart Surgery Database. Other outcomes include tracheostomy incidence, length of stay, time of decannulation if the patient had been decannulated, and mechanical ventilatory need after hospital discharge.
Statistical Analysis
Statistical analysis was performed using IBM SPSS Statistics version 20. Descriptive data are expressed as means (standard deviations) or medians (ranges) as appropriate. Categorical data were compared using the chi-squared test or Fisher’s Exact test. Continuous data were analyzed using the Mann-Whitney U test for non-normally distributed data.
Results
A total of 12 patients underwent tracheostomy placement following cardiac surgery in the 9 year study period. During this period 2459 CHS performed in our center, the incidence of tracheostomy after CHS was 0.5%. Eight of the 12 patients (66.7%) were female. The median weight at the time of surgery was 6 kg (range, 4 kg-35 kg).
The median age at the time of surgery was 210 days [interquartile range (IQR): 75-262 days]. The median time between cardiac surgery and tracheostomy was 25 days (IQR: 15-47 days). The mean PRISM score was 7.1±5.5. Eleven patients (92%) RACHS-1 score were ≥2. A large proportion of patients (10/12, 83.3%) had biventricular anatomy, among these patients atrioventricular septal defect was the most common diagnose. Two patients had single ventricle anatomy. The details of cardiac diagnosis and the cardiac surgery performed are summarized in Table 1. The median duration of mechanical ventilation was 60 days (range, 30-261 days) and the median length of PICU stay was 68 days (range, 30-301 days). The median duration of mechanical ventilation after tracheostomy was 16 days (range, 12-215 days). Demographics and patient characteristics are shown in Table 2.
Three patients who had a neurological impairment and 2 patients who had a failure of weaning underwent tracheostomy before extubation trials. Seven patients had at least 2 extubation trials. Diaphragmatic paralysis was the most common (5/12, 42%) indication for tracheostomy. Neurological impairment and hypotonicity were the next common indication and were present in 4 patients (33.3%). Direct laryngo-bronchoscopy was performed in 6 patients, 3 patients were diagnosed with tracheobronchomalacia (25%). In 2 patients, persistent cardiac insufficiency and prolonged mechanical ventilation were considered as indications for tracheostomy. Three patients (25%) had confirmed chromosomal anomalies which revealed trisomy 21 in two patients and DiGeorge syndrome in one patient. Two patients had chronic lung disease, one of them operated for tracheoesophageal fistula. Tracheostomy indications are summarized in Table 1. Genetic syndrome or at least one non-cardiac morbidity were present in 41.6% of patients.
No procedure-related complications have occurred in any of the patients during tracheostomy insertion. There were no mediastinal wound infections. Only one patient with DiGeorge syndrome had a tracheostomy site infection. Tracheitis and pneumonia were the most common complications. Before tracheostomy 10 patients (83.3%) had 14 VAP episodes whereas 7 patients (58.3%) had 9 VAP episodes after tracheostomy, although this difference was not significant (p=0.152). Pseudomonas aeruginosa was the most common pathogen (10/23, 43.4%) followed by Klebsiella pneumoniae (6/23, 26%), Stenotrophomonas maltophilia (3/23, 13%) and Acinetobacter baumannii (2/23, 8.6%).
The number of patients who underwent tracheostomy placement <14 days and <30 days were 2 (16.6%) and 7 (58.3%) respectively. Comparing VAP episodes before and after tracheostomy in patients who underwent tracheostomy within 30 days of ventilation with those who underwent tracheostomy >30 days after intubation yielded no differences (p=1.000 and p=1.000, respectively). When evaluating the duration of mechanical ventilation patients in patients who had tracheostomy within 30 days there was a reduction in the median days of mechanical ventilation (30 vs. 60 days, p=0.035). Also between this group’s duration of mechanical ventilation after tracheostomy, length of PICU stay and length of hospital stay yielded no differences (Table 3).
The median length of PICU stays after the tracheostomy was 41 days (range, 21-289 days). During the PICU stay, one patient died due to sepsis and multiorgan failure on the postoperative 47th day. Three patients were weaned from mechanical ventilation and successfully decannulated. Four patients (33%) were discharged home on mechanical ventilation and four patients (33%) on a trach collar. Two patients on a trach collar and one patient on mechanical ventilation were decannulated after PICU discharge. Among all patients with CHS undergoing tracheostomy, 6 (50%) of 12 were decannulated after a median time of 179 days (range, 34-463 days). The operative mortality was 8.3% (1/12) and the overall mortality during the first year of follow-up was 8.3% (1/12).
Discussion
In children with CHS, there is no consensus on the indications and optimal timing for tracheostomy. Although there is limited data on tracheostomy practices and outcomes in the pediatric population, recent studies reported that in PICU patients early tracheostomy may have significant benefits without adversly effecting mortality.6 Early tracheostomy placement may shorten the length of PICU stay and reduce the incidence of VAP.7 Our study population has a shorter time to tracheostomy and subjects who had tracheostomy within 30 days have a significantly shorter duration of mechanical ventilation. Two patients (patients 6 and 12) who underwent tracheostomy within 30 days, have been decannulated during their stay in PICU. The timing of tracheostomy varies according to the experience and approach of the clinician, and this may cause unnecessary or delayed tracheostomy procedures. In our cohort, there were no life-threatening complications related to tracheostomy.
Recent studies reported that patients with a history of cardiac surgery had a significantly longer duration of PICU admission to tracheostomy placement.8,9 In a multicenter study that was evaluated to describe the use of tracheostomy, the median time between initiation of mechanical ventilation and tracheostomy placement was 14.4 days with significant variation in the primary diagnosis.10 In literature, the median time for tracheostomy after CHS varies between 30-58 days.11,12
In this study, we identified a low rate of tracheostomy (0.5%) among patients after CHS and this result is comparable with previous studies. Although the incidence of tracheostomy after CHS is low, there is a significant increase over the years with possible attribution to the increased complexity of pediatric cardiac surgical procedures.1,11 The incidence of tracheostomy after cardiac surgery has increased from 0.11% in 2000 to 0.76 in 2012, according to the STS congenital heart database.1
Infants and children undergoing cardiac surgery, especially patients with single ventricle physiology have a high risk for surgical complications and airway issues leading to prolonged mechanical ventilation. In a multicenter study that examined long-term mechanical ventilation and tracheostomy timing in PICU, they reported the majority of participants had underlying cardiac disease (57%) and 67% of those who underwent tracheostomy.8 Published studies determined the several preoperative risk factors that are related to prolonged mechanical ventilation and the need for tracheostomy after CHS. Genetics and non-cardiac anomalies were present in 40-60% of the patients.1,13 Additionally, postoperative morbidities including residual lesion, delayed sternal closure, cardiac arrest, sepsis and, airway issues related to the cardiovascular surgery may lead to prolonged mechanical ventilation and difficult weaning.1,13,14 Hoskote et al.12 described the postoperative risk factors for tracheostomy after CHS as myocardial dysfunction (49%), tracheobronchomalacia (49%) and, diaphragmatic paralysis (35%). In our cohort, diaphragmatic paralysis was the most common indication for tracheostomy. Diaphragmatic plication is a successfull treatment option especially in infants with bilateral diaphragmatic paralysis.15 Tracheobronchomalacia and prolonged mechanical ventilation due to neurological impairment were other indications for tracheostomy. Genetic syndrome or non-cardiac morbidities were present in 41.6% of patients. In 4 of 5 patients with diaphragm paralaysis, plication was not performed due to accompanying tracheostomy indication such as hypotonicity and neurological disorder that required positive pressure ventilatory support.
Although the rate of tracheostomy after CHS is increasing, tracheostomy requirement after CHS is still associated with a poor clinical course, high intra-hospital and extra-hospital mortality. In our cohort, the operative mortality was 8.3% that is lower than previously reported studies.13,14 In our cohort, 11 patients (92%) RACHS-1 scores were ≥2 and 6 patients (50%) RACHS-1 scores were ≥3. Edwards et al.16 reported children with more complex lesions and greater RACHS-1 scores had higher mortality rates. They reported the 5-year survival of 68% of children with home mechanical ventilation program after CHS, but the rate was only 12% in children with RACHS-1 of 4 or higher. However, in a study in which they analyzed the results of patients who needed tracheostomy and mechanical ventilation at home after CHS, they reported that there was no statistically significant difference in decannulation between patients with a RACHS-1 score >3 and patients with a RACHS-1 score ≤3.17 In a large observational study, they demonstrated that subjects with congenital heart disease (CHD) had a 6.67 times higher risk of tracheostomy than those without CHD, and mortality risk was 3.8 times higher following tracheostomy in infants with CHD.18
In our study, the median length of PICU stay was 68 days. In our center, children requiring tracheostomy and mechanical ventilation are admitted in 5 beds intermediate unit facility. These patients have a high risk of death due to a tracheostomy-related complication after discharge. Therefore, in our clinic, the follow-up of patients with a high probability of decannulation and who may show reversibility for tracheostomy indication is followed up in this step-down unit. With this approach that patients can be followed for a longer period, it is aimed to prevent complications related to tracheostomy. In a single-center study, 5 out of 11 patients who underwent tracheostomy after CHS and died after initially being discharged home had tracheostomy-related complication.11
Study Limitations
There are some limitations of this study, as a result of it has retrospective design and a single-center study. As a result of the small number of patients in the study, a strong statistical evaluation could not be made. The study has a patient selection bias for age, the study cohort did not include the neonatal age group. Social conditions such as cooperation of the family, medical ward conditions may have affected the length of the PICU stay.
Conclusion
The early tracheostomy procedure facilitates the weaning process and shortens the duration of positive pressure ventilation. In this patient population, large scale studies are needed to identify risk factors for unsuccessful weaning and optimum timing for tracheostomy.
Ethics
Ethics Committee Approval: This study was approved by the institutional review boards with the permission for the use of patient data for publication purposes (21-1T/26, date: 07.01.2021 - Ege University Faculty of Medicine Medical Research Ethics Committee).
Informed Consent: Informed consent was received from the families.
Peer-review: Externally and internally peer-reviewed.
Authorship Contributions
Concept: P.Y.Ö., O.N.T., B.K., Design: P.Y.Ö., O.N.T., B.K., Data Collection or Processing: P.Y.Ö., E.E.T., İ.E., Analysis or Interpretation: P.Y.Ö., E.E.T., İ.E., Literature Search and Writing: P.Y.Ö.
Conflict of Interest: No conflict of interest was declared by the authors.
Financial Disclosure: The authors declared that this study received no financial support.
