Sodium Balance Analysis In The Burn Resuscitation Period.

Abstract

The different formulae for resuscitation therapy after thermal damage recommend 0.5-0.6 mmol sodium for each % TBSA burned, suggesting fluid requirements from 2-4 ml/kg/% burn because of sodium loss in burned and unburned tissues. There is a gap especially in the recommendations regarding dysnatremia in the burn population. Many studies have focused on calculating amount of resuscitation fluids, avoiding the situation of "fluid creep", and not on calculating sodium remaining in the body after resuscitation. The goal of this observational study was to provide data for sodium disturbances in the shock period after burns. Our study underscores the challenge of understanding whether there is a relationship between amount of crystalloid fluids given during resuscitation and meeting sodium needs. We set out to examine sodium balance (sodium deficit, received, excreted, and retained) after burns. The area under the ROC curve was performed by analyzing fluid and sodium load. Moreover, we conducted linear regression to analyze if there was a correlation between sodium retained and sodium excreted. Sodium deficit persisted until the second 24h despite resuscitation. Resuscitation was performed using Parkland formula, but urine output (UO) values were higher than expected. The threshold for fluid administration (ml/kg/%) or fluid load in the first 24h and sodium load (mmol/kg/%) for positive state (sodium received >0.5-0.6 mmol/kg/%) was 3.7 ml/kg/%. With linear regression, it was evident that sodium excreted was responsible for sodium retained, indicating a moderate correlation in the first 24h and a strong correlation in the second 24h. Resuscitation with LR did not correct hypoosmolality hyponatremia, which persisted even after the first 24h, especially in patients with burns >60%. If more than 3.7 ml/kg/% of LR is given, a sodium load higher than the normal level will be introduced, leading to increased urinary output, elevated sodium excretion, and non-correction of plasma sodium at the end of resuscitation. What is important for colleagues in clinical practice is that the focus of burn resuscitation should be expanded with data regarding sodium balance and the impact of dysnatremias in morbidity and mortality.