Impact of hypernatremia on burn wound healing: results of an exploratory, retrospective study

Severely burned patients need extensive initial fluid resuscitation. Formulas to calculate fluid needs during burn shock are well established. However, protocols for normalizing circulating fluid volume after cellular integrity has recovered do not exist. Resultant electrolyte shifts can cause hypernatremia, a possible sign of hypovolemia, which may in turn result in decreased tissue perfusion, subsequently affecting burn wound healing. The purpose of this retrospective chart review was to explore the hypothesis that hypernatremia in burn patients is a possible sign of systemic dehydration and that dehydration may affect burn wound skin graft take. Medical chart data from otherwise healthy burn victims with deep partial-thickness burns (total burn surface area [TBSA] >10%) who underwent skin grafting 7 days post injury were reviewed. Thirty (11 female; 19 male) patients with an average TBSA of 30% (± 11%) and an Abbreviated Burn Severity Index (ABSI) score of 7.9 (± 1.8) were included. Of those, 17 had normal average serum levels between day 2 and 6 following injury and 13 developed hypernatremia (serum sodium ≥146 mmol/L) an average of 5.5 days (± 1.5) after injury. Patients in this group underwent an average of 1.3 (± 0.8) re-grafting procedures compared to 0.35 (± 0.5) for patients without hypernatremia (P = 0.001). There was good correlation (r = 0.525) between daily infusion-diuresis ratios (IDR) and serum sodium levels, as well as between serum sodium levels and re-skin grafting occurrences (r = 0.62). The results indicate that research to confirm that hypernatremia is an indicator of dehydration and affects skin graft take is warranted and that protocols to optimize fluid volume following burn shock treatment are needed.