Metabolic acidosis in patients with diabetes 2 undergoing cardiac surgery

BACKGROUND Sodium-glucose cotransporter 2 inhibitors (SGLT2-i) lower blood sugar and reduce cardiovascular events and kidney failure. However, there have been increasing reports of euglycaemic diabetic ketoacidosis (eDKA) linked to SGLT2-i medicines. OBJECTIVE Investigating the association between SGLT2-i use and the incidence of metabolic acidosis in patients with type 2 diabetes undergoing cardiac surgery. DESIGN A retrospective observational cohort study comprising 121 patients, with 38 in the SGLT2-i group and 83 in the control group. SETTING A 2-year period at Haukeland University Hospital, a tertiary regional hospital in Western Norway. PATIENTS Patients with type 2 diabetes undergoing cardiac surgery. INTERVENTIONS Collection of clinical and laboratory data, including acid/base balance parameters, surgery details and SGLT2-i use. MAIN OUTCOME MEASURES Base excess and anion gap measurements as indicators of ketosis development. A subgroup analysis in patients without renal failure (glomerular filtration rate > 60 ml min −1 m −2 ) . RESULTS Lower base excess levels and increased anion gaps were observed in the SGLT2-i group compared with controls at various time points postoperatively, with no significant differences in serum lactate levels. Twelve hours postoperatively, 41% of SGLT2-i patients without renal failure had a base excess -3 mmol l −1 or less after correction for serum lactate (indicating ketosis) compared with only 8% in the control group ( P < 0.001). The anion gap was elevated in the SGLT2-i group compared to the control group at 12 h postoperatively ( P = 0.018). Multivariable regression analysis identified SGLT2-i use as an independent factor associated with a lower base excess after correction for lactate levels ( P < 0.001). Cessation of SGLT2-i medication did not correlate with the degree of acidosis. CONCLUSION While taking SGLT2 inhibitors, diabetic patients undergoing heart surgery are at an increased risk of ketosis and possibly metabolic acidosis. This emphasises the importance of careful observation and effective treatment strategies within this group.