Risk factors of sepsis and prevalence of multidrug‐resistant organisms in pediatric cardiac surgery in tertiary care teaching rural hospital in India: A retrospective observational study

Abstract Background and aims Cardiac surgery and cardiopulmonary bypass result in an immunoparalyzed state in children making them susceptible to sepsis and other hospital‐acquired infections. Therefore, identification of the risk factors of sepsis would lead to appropriate management. The current study seeks to evaluate the prevalence of sepsis and risk factors linked to sepsis in pediatric cardiac surgical patients and the subsequent prevalence of multidrug‐resistant organisms. Methods A retrospective, single‐center observational study was conducted including 100 pediatric patients admitted to the pediatric intensive care unit (ICU) after cardiac surgery between January 2017 and February 2018. All patient data were obtained from the medical record department of the hospital. Patient case report form comprised demography, surgery details, preoperative and postoperative hematological reports, and clinical details. After collecting the data, chi‐square test and logistic regression analysis were used to determine the risk factors linked to sepsis. Results The prevalence of sepsis in our population was 27% and the mortality rate due to sepsis was 1%. The only statistically significant risk factor for sepsis we discovered in this analysis was prolonged ICU stay for more than 5 days. A total of eight patients had blood cultures positive for bacterial infection. The alarming finding was that all eight were infected with multidrug‐resistant organisms, demanding the last line of antibacterials. Conclusion Our study indicates that special clinical care is required when ICU stay is prolonged to lower the risk of sepsis. These new and upcoming infections not only promote high mortality and morbidity rates but also contribute to increased cost of care due to the use of newer broad‐spectrum antibiotics and longer hospital stay. The high prevalence of multidrug‐resistant organisms is unacceptable in the current scenario and hospital infection and prevention control play a crucial role in minimizing such infections.

Furthermore, chronic hypoxia, low cardiac output syndrome, and other comorbid conditions linked to CHD, [3][4][5] as well as invasive devices may also elevate the risk of sepsis in this population.
Despite extensive adoption of healthcare guidelines and sepsis prevention strategies, the frequency of healthcare-acquired infection remains high, at 6%-30.8% in pediatric cardiac surgical patients.
Sepsis is a significant and individual risk factor for increased duration of mechanical ventilation, cardiac intensive care unit (ICU) length of stay, healthcare costs, and mortality in children with CHD.
Very few case series of sepsis prevalence in pediatric cardiac surgical patients, in a rural tertiary care hospital from India have been documented. None of them has indicated the lingering threat of increasing prevalence of multidrug-resistant organisms.
In this study, we aimed to assess the prevalence of sepsis and the risk factors associated with it in pediatric cardiac surgical patients and the subsequent prevalence of multidrug-resistant organisms.

| Exclusion criteria
• Older patients and patients undertaking any major non-cardiac surgical intervention.
• Also, patients discharged against medical advice, having a preadmission infection, or patients transferred from other hospital departments or other centers with infection.

| Data collection
The study was implemented after receiving authorization from the Institutional Ethics Committee of the hospital. It was a retrospective observational study so the Informed consent form was rescinded by the Institutional Ethics Committee.
The study included 100 pediatric patients (less than 14 years) who had cardiac surgery between January 2017 and February 2018.
All the data of the patients were received from the medical record department of the hospital. The case report form was compiled in English.
To look for the related risk factors for sepsis patients clinical and laboratory data were obtained in case report form. Such data are the patient's demographic data including sex, age, weight, height, cardiac and noncardiac abnormalities, and major medical history. Preoperative sepsis screen and risk factors of immunesuppression like severe mal-nutrition, chromosomal disorders, HIV infection, and use of preoperative antibiotics and hospital stay were obtained.
Surgery data were obtained with surgery type, risk adjustment for congenital heart surgery (RACHS) score for assessing surgical complexity, CPB duration, hypothermia or total circulatory arrest, delayed sternal closure, intubation and ventilation duration, need for reintubation, central catheter lines, and its duration, length of ICU stay, blood transfusion, inotropic support, renal support, and tracheostomy.
Hematology data included were preoperative and postoperative hemoglobin level, leukocytes count, C-reactive protein, procalcitonin, and culture reports recorded from the medical records of the patients. In the case of a positive culture report, antibiotics sensitivity sequence and their minimum inhibitory concentration were recorded.
Mortality with its cause was also highlighted.
The definition of sepsis and septic shock was determined as per the definition mentioned in Sepsis-3. Suspected sepsis was labeled when a patient was managed as sepsis, based on clinical and laboratory parameters.

| Statistical analysis
Data were expressed as mean and standard deviation with minimum and maximum values or as numbers and percentages according to the type of data. An Independent student t-test was employed for the comparison of numerical data and a chi-square test for categorical data. Logistic regression analysis was employed to evaluate the risk factors linked to sepsis.

| RESULTS
One hundred and three pediatric patients with age less than 14 years, had undertaken cardiac surgery during the period from January 2017 to February 2018. Three patients who were discharged against medical advice or transferred to other centers were exempted from the study.
One hundred patients, 55 males and 45 females, were eventually included in this study and were observed retrospectively for the occurrence of sepsis after cardiac surgery (Table 1).
Regarding patients' weight, 58 patients were more than 5 kg and 36 patients were between 2.5 and 5 kg, whereas only six patients were less than 2.5 kg in weight.
A total of eight patients were in the age group of <30 days (neonates), 44 patients were in the age group of 30 days-1 year (infants), 30 patients were in the age group of 1-5 years, and 18 patients were in the age group of 5-14 years.
In this research, eight patients had blood culture-proven sepsis.
Another eight patients had suspected sepsis that emerged after surgery, while 11 had suspected sepsis that emerged preoperatively during hospital stay ( Table 2).
In our study group, there was no report of mediastinitis or endocarditis. Although six patients had sternal wound gaping. Swab culture from these patients was sterile. They improved on oral antibiotic administration. Two patients died (Table 3).
Among the type of surgery, ventricular septal defect (VSD) closure surgery had a greater prevalence. A total of 14 patients underwent VSD closure, and 4 (28%) of them had sepsis.
As we inserted risk factors data in chi-square statistics (Table 4) Multivariate logistic regression analysis was conducted to evaluate the risk factors of sepsis ( Table 5). The analysis revealed that the risk factors were linked only to the length of ICU stay.
Prolonged duration of ICU stay of more than 5 days (<0.05) was a statistically significant risk factor for sepsis.
The eight patients who had blood cultures positive for bacterial infection mostly were positive for nosocomial gram-negative bacteria. One was Enterococcus faecium. The unsettling discovery is that T A B L E 1 Demographic and surgical characteristics.

| CONCLUSION
The prevalence of sepsis in this research was 27%, which is similar to other studies. With the application of adequate sepsis guidelines, its prevalence can be decreased further to 5% as in a recent study.
There is a high incidence of multidrug-resistant organisms in culture-positive patients with sepsis. If immediate steps are not taken to contain it, we may lose many patients because of sepsis caused by resistant bacteria. Misuse and overuse of antibiotics may further worsen the problem.
In this study, prolonged ICU stay was a statistically significant risk factor for sepsis. It indicates that special clinical care is required when ICU stay is prolonged to lower the risk of sepsis.

| LIMITATIONS OF THE STUDY
As it is a retrospective study, some data discrepancies cannot be exempted. Although care has been taken to minimize it. Many other risk factors were not statistically significant because the study group was not sufficiently powered. As it is a single-center study, its findings cannot be generalized for entire pediatric cardiac surgery centers in a region or country.