We thank the reader for his astute observations of our study findings [1]. Two methods that are commonly used to measure serum b-hydroxybutyrate (BOHB) in the laboratory are colorimetric method and spectrophoto-metry. Both methods are unavailable in most laboratories due to the prohibitively high cost of estimation and average time range from two to six hours based on the method of estimation, analysis of a number of samples and workforce available in the laboratory. In our study, we used Cayman colorimetric BOHB estimation kits, which had 96 wells (including those for control samples). Hence, samples were stored at -80°C and measured at the end of the study. Thus, real estimation time was not possible using this method. The spectrophotometric method of BOHB estimation is more widely used. It provides quick results (varying from the laboratory to laboratory), and is very accurate [1].　

Regarding the concern about BOHB values >5 mmol/L, the total number of samples tested in the study were 236, out of which 42 capillary samples had a BOHB ³5.0 mmol/L. We align with the reader’s concern about the utility of BOHB measurement and hyperchloremic metabolic acidosis (HCMA), a potential cause of persistent metabolic acidosis in patients with DKA. As HCMA is a complication seen in a handful of patients towards the latter part of DKA management, blood gas analysis cannot be completely excluded. However, capillary BOHB can aid in reducing the frequency of blood gas analysis early on during the treatment course as it correlates well with pH, especially when HCMA has not set in. Hence, monitoring of ketonemia (BOHB) is one of the endpoints of diabetic ketoacidosis (DKA), where metabolic acidosis targeted approach might lead to an unnecessary continuation of therapy despite resolution of DKA by that time [3].　

1. Kurup PM, Rameshkumar R, Soundravally R, Satheesh P. Capillary versus serum b-hydroxybutyrate in pediatric diabetic ketoacidosis. Indian Pediatr. 2019;56:126-9.