Introduction:

Peri-operative organ injury is one of the most common causes of morbidity and mortality in surgical patients. Among different types of peri-operative organ injury, Acute Kidney Injury (AKI) occurs with substantial frequency and has significant deleterious effect on post-operative outcomes of the patients. ^1,4,6 Post-operative AKI has been linked with increased incidence of chronic kidney disease (CKD), higher morbidity, short- and long-term mortality, higher cost, and higher resource utilisation, compared to patients without post-operative AKI. ^1,2,5 AKI in children has been found to have significant associations with in-hospital mortality and longer duration of admission.³

Significance of post-operative AKI in adults is also established in various studies, like STARSurg Collaborative, Edinburgh, UK (2016), which concluded that post-operative AKI is associated with significantly worse clinical outcomes at the one-year-mark^.6, Park and Junk Tak also suggest that post-operative AKI is one of the most common causes of kidney injury in surgical patients.⁷. Wingert Tq et al also concluded that Postoperative AKI was found to be associated with significantly higher rates of mortality and 30-day readmission in paediatric patients undergoing non-cardiac surgery.³

In recent years, evidence in both basic science and clinical research has led to a new understanding that AKI is not a single-organ injury. Not only AKI is a multifaceted systemic disease process but also potentially endangers other systems too including pulmonary, cardiac, neurologic, immunologic, hepatic, and gastro-intestinal. The development of acute kidney injury has important implications for recovery and outcomes of surgical patients. Decreased urine output and an increase in serum creatinine concentrations are classically used to diagnose acute kidney injury.¹

Aim and Objectives:

To calculate the incidence of Post-operative AKI following major abdominal surgeries in pediatric population, in last 3 years using Pediatric KDIGO criteria.

Primary Outcome:

The primary outcome is the incidence of Post-operative AKI, measured for the last three years in paediatric population, following major abdominal surgeries.

Secondary Outcome:

The secondary outcome to be studied are incidence of mortality, morbidity, need for renal replacement therapy, association with ASA status.

Material and Methods:

Ethics: The study will be undertaken after obtaining approval from Institutional Ethics Committee (IEC).

Patients: The study will include all pediatric patients at Tata Memorial Hospital who have undergone major abdominal surgeries under general anaesthesia, in last three years (June 2018 to May 2021).

Location: The study will be conducted in the Department of Anaesthesiology, Critical Care and Pain at Tata Memorial hospital.

Place of Study: Tata Memorial Hospital

Type of Study: Retrospective Observational Data Collection

Duration: June 2018 to May 2021

Sample size calculation: The total number of patients included in this study will be 300.

Methodology:

Inclusion criteria: All pediatric patients (aged 12 years or below) undergoing major abdominal surgeries in the last three years (June 2018 to May 2021)

Exclusion criteria: All patients who did not fulfil the inclusion criteria, and those whose data were incomplete.

Details of Study Procedures Involved:

Data will be collected from the electronic medical record system (EMR) of the hospital which contains patients’ clinical and laboratory data. Data will also be recorded from the patient’s case file, the anaesthesia and PACU (intra-operative and postoperative) management summaries, monitoring charts and the surgical notes. No additional interventions will be performed. No additional hospital visits will be required.

The following data will be collected–Demographics, co-morbidities and their treatment, chemotherapy taken, preoperative hemogram, Renal and Liver Function Tests, coagulation studies, site of disease, preoperative medication, type of surgery, type of anaesthesia (General + Regional), Pre-procedure radiological scan (contrast use).

Patient undergone major abdominal surgeries will be analyzed for the length of their hospital stay (up to a maximum of 30 days). The first serum creatinine value in the post-operative period and the maximum serum creatinine value upto 30 days of operation will be noted , total blood loss, intravenous fluid replacement (colloids and crystalloids), Blood and Blood Components transfused, urine output, Episodes of  hypotension, use of vasopressors and inotropes, body temperature, pre-operative and the lowest post-operative eGFR, lowest post-operative 24 hour urine output, use of nephrotoxic agent (NSAIDs and antibiotics), morbidity (surgical calculations according to Clavein Dindo classification), length of hospital stay, ICU stay and re-admissions, duration of ventilation, and status at hospital discharge or at 30 days, whichever is earlier (alive or dead) will be noted.

Postoperative AKI will be graded in severity by use of KDIGO criteria,

Stage 1: is Increased sCr of 1.5-1.9 times baseline within 7 days OR sCr increase ≥ 0.3 mg/dl within 48 h OR urine output < 0.5 ml/kg/h for 6-12 h,

Stage 2: is Increased sCr of 2.0-2.9times baseline OR urine output < 0.5 ml/kg/h for >12h

Stage 3: is Increased sCr of 3.0 times baseline or more or sCr ≥ 4 mg/dl OR initiation of RRT or GFR decrease to <35 ml/min (1.73 m)–2 in patients < 18 years old OR urine output <0.3ml/kg/h for ≥ 24h OR anuria for ≥ 12 h

Clavien Dindo Classification

Grade I -Any deviation from the normal postop course without the need for pharmacological treatment or surgical, endoscopic and radiological interventions e.g. antiemetics, antipyretics, analgesics, diuretics and electrolytes and Physio therapy wound infections opened at the bedside

Grade II- Requiring pharmacological treatment with drugs other than such allowed for grade I complications.

 Grade III- Requiring surgical, endoscopic or radiological intervention

          - IIIa- Intervention not under general anesthesia/

          -IIIb -Intervention under general anesthesia

 Grade IV Life-threatening complication (including CNS complications) requiring ICU-management

         - IVa- Single organ dysfunction (including dialysis)/

         - IVb- multi-organ dysfunction​

Complete patient confidentiality and privacy will be maintained. Each patient whose data is collected will be identified by a unique number to hide his/her identity.

Budget: 

This study will not incur any additional costs on patients or Tata Memorial Hospital.

Statistical Analysis Plan

The study aims to calculate the incidence of Post-operative AKI following major abdominal surgeries in pediatric population, in the last 3 years using Pediatric KDIGO criteria (Stage I, II and III).

The creatinine levels and urine output variables are continuous variables and the stage of AKI calculated as per the KDIGO criteria will be a categorical variable.

Incidence to be calculated as the ratio of the number of pediatric patients who developed AKI and the total number of pediatric patient who were included in the study.

For measuring the association between the variables, first the normality test will be run.

Categorical data will be reported in percentage and frequency. Continuous variable will be reported in mean and IQR.

Logistic regression will be used to determine independent predicator for AKI.

The analyses will be carried out on IBM SPSS v25.0.