Acute isotonic hyponatremia after single dose histidine-tryptophan-ketoglutarate cardioplegia: an observational study

• Published in: Perfusion Vol. 36; no. 5; pp. 440 - 446
• Main Authors: van Houte, Joris, Bindels, Alexander J, Houterman, Saskia, Dong, Phi Vu, den Ouden, Monique, de Bock, Nina E, Verberkmoes, Niels J, Curvers, Joyce, Bouwman, Arthur R
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01-07-2021; Sage Publications Ltd
• Subjects: Acid-base status; Anesthesia; Blood; Cardioplegic Solutions - adverse effects; Heart; Heart Arrest, Induced - adverse effects; Heart surgery; Histidine; Humans; Hyponatremia; Hyponatremia - drug therapy; Observational studies; Osmosis; Prospective Studies; Sodium; Surgery; Tryptophan; myocardial protection; isotonic hyponatremia; custodiol; cardioplegia; histidine-tryptophan-ketoglutarate; acute hyponatremia; HTK
• ISSN: 0267-6591; 1477-111X
• DOI: 10.1177/0267659120946952

Introduction:
Histidine-tryptophan-ketoglutarate cardioplegia is used for prolonged myocardial protection in complex cardiac surgery. Administration leads to acute hyponatremia in a majority of patients, because of its low sodium concentration (15 mmol/L). However, histidine-tryptophan-ketoglutarate solution’s osmolality is slightly hypertonic (310 mOsm/kg). Hypothesized was that acute isotonic hyponatremia will be induced, which does not need to be corrected with hypertonic saline.
Methods:
Cardiac surgery patients who received histidine-tryptophan-ketoglutarate cardioplegia were included in this prospective single center study. Serial blood samples were taken from each patient at five different time points: after induction of anesthesia (T1) and 10 minutes (T2), 6 hours (T3), 12 hours (T4), and 18 hours (T5) after administration of histidine-tryptophan-ketoglutarate cardioplegia, respectively. Blood samples were analyzed for sodium concentration, osmolality, and acid-base balance.
Results:
Twenty-five patients were included. Median blood sodium levels decreased from 140 [138-141] at T1 to 128 [125-130] mmol/L at T2 (p < 0.001). At T3, T4, and T5, median blood sodium concentrations were 136 [134-138], 139 [137-140], and 140 [137-142] mmol/L, respectively. Median osmolality was 289 [286-293] at T1 and increased to 296 [291-299] mOsm/kg (p < 0.001) at T2. At T3, T4, and T5, osmolality was 298 [292-302], 298 [294-304], and 300 [297-306] mOsm/kg, respectively. Median pH decreased from 7.38 [7.36-7.40] at T1 to 7.30 [7.27-7.32] at T2 (p < 0.001).
Conclusion:
Administration of histidine-tryptophan-ketoglutarate cardioplegia during cardiac surgery leads to acute moderate to severe isotonic hyponatremia, which resolves spontaneously in the first 18 hours perioperatively. Correction with hypertonic saline is not necessary.