Frequency of Acute Kidney Injury in tetanus patients of Paediatric Intensive Care Unit: A public hospital experience

Background and Objective: Tetanus is a potentially fatal but preventable disease. Mortality is related to severity of the disease, cardiovascular, pulmonary and renal complications. Acute kidney injury (AKI) is a frequent and lethal complication of tetanus. The objective was to determine the frequency of AKI in tetanus patients managed in a public hospital.

Methods: Children aged 1-12 years admitted in Paediatric Intensive Care Unit (PICU) with the clinical diagnosis of tetanus over three and half years were recruited for the retrospective study. pRIFLE (Pediatric Risk, Injury, Failure, Loss, End) criteria was applied to all cases of tetanus to categorize them as having AKI or not, on the basis of estimated creatinine clearance (ECCL). Comparison was done between AKI and non-AKI cases, as well as between AKI survivors and AKI non-survivors. The study was conducted at PICU of Dr. Ruth K.M. PFau Civil Hospital Karachi for tetanus cases admitted during July 2013 to December 2016.

Results: During the study period, 44 patients of tetanus were enrolled. Nearly 32 % of tetanus patients developed acute renal dysfunction according to PRIFLE criteria. There were overall 15 (34.09%) expiries among tetanus patients among which nine (60%) had AKI. Oliguria was observed in five (35.71%) cases. All the AKI non-survivors had ECCL below 50% and all had autonomic instability. AKI developed towards the end of first week in three cases, mid of second week in four cases and third week in seven cases. Renal replacement therapy (RRT) i.e. peritoneal dialysis (PD) was done in four AKI cases but it did not improve the outcome. CRP was more than 50 in 24 (54.54%) cases. Ventilatory support was given to 85.71 % with AKI as compared to 66.66 % of non AKI patients.

Conclusion: Development of AKI in tetanus is multifactorial. Major contributors are severity of the tetanus itself, presence of autonomic instability, ventilator dependency, and sepsis. Presence of AKI worsens the outcome of tetanus in terms of survival, length of stay, hospital cost and ventilator days.