Increased mortality in hypernatremic burned patients

Severe Burn Injuries - The Day the Sodium Starts Rising

BACKGROUND/AIM

The current study was designed to evaluate the etiologies of hypernatremic episodes in patients with severe burn injuries in comparison to critically ill non-burn patients.

PATIENTS AND METHODS

The retrospective data acquisition was limited to the first 14 days and to patients with at least 20% total body surface area (TBSA) 2nd degree burn injuries or more than 10% TBSA when including areas of 3rd degree burn injuries. The results were compared to the results of a previously published study that analyzed the risk factors for hypernatremia in 390 non-burn intensive care unit patients.

RESULTS

In total, 120 patients with a total of 50 hypernatremic episodes were included. Compared to non-burn injury patients, no significant differences were detectable except for a lower rate of hypokalemia and a higher rate of mechanical ventilation. The main trigger for hypernatremic episodes was the loss of free water, while 24% of the hypernatremic episodes seemed to be at least partly triggered by a surplus sodium influx. Patients with hypernatremic episodes had a significantly higher mortality rate. However, in none of the cases was hypernatremia the decisive cause of death.

CONCLUSION

Besides the unique phenomenon of high volume internal and external volume shifts, the overall risk factors and etiologies of hypernatremia in patients with severe burn injury do not seem to significantly differ from other ICU patient collectives. Remarkably, a surplus of sodium influx and therefore a modifiable factor besides the specific burn injury volume resuscitation had an impact on the hypernatremic episodes in 24% of cases.

Hypernatremia Risk Factors And Prognostic Impact In Burn Patients: A Case Control Study

Hypernatremia is associated with poor outcomes in critically ill patients. Hypernatremia risk factors in burned patients are not well studied. We aimed to identify hypernatremia risk factors and to evaluate outcomes in burned patients admitted to our burns intensive care unit. A case control study was conducted in adult burned patients hospitalized between January 1st 2017 and December 31st 2019. Cases who developed hypernatremia (>145 meq/L) during hospitalization were matched 1:1 with controls based on age and total burn surface area. There were 57 cases and 57 controls with a mean age of 41 ± 18 years. The majority of patients had major burns (n=99, 86.8%). The time onset of hypernatremia was seven days post burn. Compared to controls, the case group mostly consisted of transferred patients with longer time from injury to intensive care unit admission. Inhalation injury, mechanical ventilation, intravenous fosfomycin and colistin were associated with hypernatremia. Admission to the intensive care unit after six hours post-burn was the independent risk factor (OR=4.5). Hypernatremia was associated with longer length of stay and with higher mortality. We conclude that delayed management, inhalation injury, mechanical ventilation, fosfomycin and colistin administration are the main hypernatremia risk factors in burned patients.

Mortality following combined burn and traumatic brain injuries: An analysis of the national trauma data bank of the American College of Surgeons

BACKGROUND

Severe burn and traumatic brain injuries (TBI) lead to significant mortality, and combined burn-TBI injuries may predispose towards even worse outcomes. The purpose of this study was to investigate the mortality of patients with burn, burn with non-TBI trauma, and combined burn/TBI to determine if combined injury portends a worse outcome.

METHODS

We obtained the National Trauma Data Bank from 2007 to 2012, identifying 32,334 patients with burn related injuries, dividing this cohort into three injury types: BURN ONLY, BURN with TRAUMA/NO TBI, and BURN with TBI. For each patient, demographic data was obtained, including age, gender, presence of trauma, TBI, or inhalation injury, burn total body surface area (TBSA), Glasgow Coma Scale, Injury Severity Score, and mortality. Multivariable logistic regression was performed.

RESULTS

Age, gender, and TBSA were similar across the three injury groups, but the incidence of inhalation injury was doubled in the BURN with TRAUMA/NO TBI (15.4 %) and BURN with TBI (15.3 %) groups when compared to the BURN ONLY (7.2 %) group. Mortality differed across injury categories after adjusting for age, TBSA, and inhalation injury. Increased mortality was seen in BURN with TRAUMA/NO TBI versus BURN ONLY (OR = 1.27 [1.06, 1.53]) and was higher when comparing BURN with TBI versus BURN ONLY (OR = 4.22 [2.85, 6.18]). BURN with TBI also had higher mortality when compared to BURN with TRAUMA/NO TBI (OR = 3.33 [2.30, 4.82]). The logs odds of mortality also increased with increasing age, TBSA and presence of inhalation injury.

DISCUSSION

This analysis of the NTDB suggests that mortality following burn-related injuries may be higher when burn injury is combined with TBI when compared to burns with other trauma, even after correcting for age, TBSA, and inhalation injury. Further clinical and laboratory research is needed to validate these findings and better understand how to optimize combined TBI and burn injury treatment.

The Link between Hypermetabolism and Hypernatremia in Severely Burned Patients

Hypernatremia is common in critical care, especially in severely burned patients. Its occurrence has been linked to increased mortality. Causes of hypernatremia involve a net gain of sodium or a loss of free water. Renal loss of electrolyte-free water due to urea-induced osmotic diuresis has been described as causative in up to 10% of hypernatremic critical ill patients. In this context, excessive urea production due to protein catabolism acts as major contributor. In severe burn injury, muscle wasting occurs as result of hypermetabolism triggered by ongoing systemic inflammation. In this retrospective study, severely burned patients were analysed for the occurrence of hypernatremia and subsequent signs of hypermetabolism. The urea: creatinine ratio—as a surrogate for hypermetabolism—sufficiently discriminated between two groups. Four of nine hypernatremic burn patients (44%) had a highly elevated urea: creatinine ratio, which was clearly associated with an increased urea production and catabolic index. This hypermetabolism was linked to hypernatremia via an elevated urea- and reduced electrolyte-fraction in renal osmole excretion, which resulted in an increased renal loss of electrolyte-free water. In hypermetabolic severely burned patients, the electrolyte-free water clearance is a major contributor to hypernatremia. A positive correlation to serum sodium concentration was shown.

Risk factors and outcome of Hypernatremia amongst severe adult burn patients

A descriptive study was conducted on 135 adult severe burn patients treated at the Burn ICU, National Institute of Burns from 1/2017 to 12/2017. Hypernatremia was defined as increased plasma sodium ≥ 146 mmol/l. It was recorded in 24.4% of total patients with onset time of 8.3 ± 4.8 days, ranging from the 5th to 21st day postburn. Moderate and severe hypernatremia was recorded in 16 (54.5%) patients. Multivariate logistic analysis indicated that increased age, burn extent, mechanical ventilation and ventilation duration were independent predictive factors for the development of hypernatremia. Significantly higher mortality rate (59.5% vs. 40.5% respectively; p = .001) and longer duration of stay in the ICU (23.2 ± 15.4 days vs. 16.2 ± 11.6; p = .01) and in the hospital (74.4 ± 43.7 days vs. 37.9 ± 22.9; p = .002) were seen in the hypernatremia group compared to normonatremic patients. It is necessary to find further effective interventions for the prevention and treatment of this fatal complication among severe burn patients.

Sodium variability is associated with increased mortality in severe burn injury

BACKGROUND

Dysnatremias are associated with increased mortality in critically ill patients. Hypernatremia in burn patients is also associated with poor survival. Based on these findings, we hypothesized that high plasma sodium variability is a marker for increased mortality in severely burn-injured patients.

METHODS

We performed a retrospective review of adult burn patients with a burn injury of 15% total body surface area (TBSA) or greater from 2010 to 2014. All patients included in the study had at least three serum sodium levels checked during admission. We used multivariate logistic regression analysis to determine if hypernatremia, hyponatremia, or sodium variability independently increased the odds ratio (OR) for death.

RESULTS

Two hundred twelve patients met entry criteria. Mean age and %TBSA for the study was 45 ± 18 years and 32 ± 19%. Twenty-nine patients died for a mortality rate of 14%. Serum sodium was measured 10,310 times overall. The median number of serum sodium measurements per patient was 22. Non-survivors were older (59 ± 19 vs. 42 ± 16 years) and suffered from a more severe burn injury (50 ± 25% vs. 29 ± 16%TBSA). While mean sodium was significantly higher for non-survivors (138 ± 3 milliequivalents/liter (meq/l)) than for survivors (135 ± 2 meq/l), mean sodium levels remained within the laboratory reference range (135 to 145 meq/l) for both groups. Non-survivors had a significantly higher median number of hypernatremic (> 145 meq/l) measurements (2 vs. 0). Coefficient of variation (CV) was significantly higher in non-survivors (2.85 ± 1.1) than survivors (2.0 ± 0.7). Adjusting for TBSA, age, ventilator days, and intensive care unit (ICU) stay, a higher CV of sodium measurements was associated with mortality (OR 5.8 (95% confidence interval (CI) 1.5 to 22)). Additionally, large variation in sodium ranges in the first 10 days of admission may be associated with increased mortality (OR 1.35 (95% CI 1.06 to1.7)).

CONCLUSIONS

Increased variability in plasma sodium may be associated with death in severely burned patients.

Continuous veno-venous hemodialysis and filtration for extensive burn with severe hypernatremia

Case

A 51-year-old man presented with severe burns, with a burn index of 33.5. Relaxation incisions were made in the trunk and right arm. Ringer's solution (12,000 mL) was used as initial fluid therapy for the first 24 h. The patient's serum Na level gradually increased to 170 mEq/L; infusion was carried out to correct the hypernatremia. Continuous veno-venous hemodialysis and filtration succeeded in maintaining the serum Na level at approximately 145 mEq/L.

Outcome

After the initiation of continuous veno-venous hemodialysis and filtration, the skin graft survival rate improved markedly with the normalization of the Na level, and the patient recovered smoothly. He was discharged on foot.

Conclusion

Hypernatremia, frequently observed in patients with extensive burns, is considered to be markedly disadvantageous for the survival of skin grafts. Continuous veno-venous hemodialysis and filtration may be one of the options for the treatment of refractory hypernatremia in severe burns.