A protocol for resuscitation of severe burn patients guided by transpulmonary thermodilution and lactate levels: a 3-year prospective cohort study

Abstract

IntroductionThe use of urinary output and vital signs to guide initial burn resuscitation may lead to suboptimal resuscitation. Invasive hemodynamic monitoring may result in over-resuscitation. This study aimed to evaluate the results of a goal-directed burn resuscitation protocol that used standard measures of mean arterial pressure (MAP) and urine output, plus transpulmonary thermodilution (TPTD) and lactate levels to adjust fluid therapy to achieve a minimum level of preload to allow for sufficient vital organ perfusion.MethodsWe conducted a three-year prospective cohort study of 132 consecutive critically burned patients. These patients underwent resuscitation guided by MAP (>65 mmHg), urinary output (0.5 to 1 ml/kg), TPTD and lactate levels. Fluid therapy was adjusted to achieve a cardiac index (CI) >2.5 L/minute/m2 and an intrathoracic blood volume index (ITBVI) >600 ml/m2, and to optimize lactate levels. Statistical analysis was performed using mixed models. We also used Pearson or Spearman methods and the Mann-Whitney U-test.ResultsA total of 98 men and 34 women (mean age, 48 ± 18 years) was studied. The mean total body surface area (TBSA) burned was 35% ± 22%. During the early resuscitation phase, lactate levels were elevated (2.58 ± 2.05 mmol/L) and TPTD showed initial hypovolemia by the CI (2.68 ± 1.06 L/minute/m2) and the ITBVI (709 ± 254 mL/m2). At 24 to 32 hours, the CI and lactic levels were normalized, although the ITBVI remained below the normal range (744 ± 276 ml/m2). The mean fluid rate required to achieve protocol targets in the first 8 hours was 4.05 ml/kg/TBSA burned, which slightly increased in the next 16 hours. Patients with a urine output greater than or less than 0.5 ml/kg/hour did not show differences in heart rate, mean arterial pressure, CI, ITBVI or lactate levels.ConclusionsInitial hypovolemia may be detected by TPTD monitoring during the early resuscitation phase. This hypovolemia might not be reflected by blood pressure and hourly urine output. An adequate CI and tissue perfusion can be achieved with below-normal levels of preload. Early resuscitation guided by lactate levels and below-normal preload volume targets appears safe and avoids unnecessary fluid input.

The Diagnosis and Hemodynamic Monitoring of Circulatory Shock: Current and Future Trends

“…A lactate optimization strategy, as well as targeting CI, ITBV, EVLW and MAP in burn patients, was shown to avoid unnecessary fluid administration and provide adequate tissue perfusion at the same time [57].…”

A systematic database-derived approach to improve indexation of transpulmonary thermodilution-derived global end-diastolic volume

“…Considering the large variability of biometric parameters such as body weight (BW) and height volumetric parameters are usually adjusted for these biometric variables to improve inter-individual comparisons and to allow for homogenous normal ranges. GEDV indexed to body surface area (BSA) is termed GEDVI and has been demonstrated to be useful in assessing preload and to guide fluid therapy in several studies [1][2][3][4][5][6][7]. Nevertheless, some studies using algorithms based on GEDVI have failed to improve outcome [8,9].…”

An overview on fluid resuscitation and resuscitation endpoints in burns: Past, present and future. Part 2 — avoiding complications by using the right endpoints with a new personalized protocolized approach

“…Numerous studies have shown that these volumetric indices represent preload more precisely when compared to urine output [30,31] or cardiac filling pressures [50,53], which are prone to missing hypervolemia as it is poorly represented by the blood pressure, filling pressure and/or urine output in the early resuscitative phase [31]. By measuring the ejection fraction to correct these volumetric preload parameters, the ability of these parameters to assess changes in preload over time can be further improved [53].…”

“…This consists of the interstitial, intracellular and intra-alveolar water of lung tissue. This parameter, together with the pulmonary vascular permeability index (PVPI), can be used to determine the presence of lung edema which can be very useful as a safety parameter during resuscitation [31]. This is particularly applicable in patients with inhalation injuries or in guiding fluid de-resuscitation if a patient fails to proceed to the "flow" phase [1−3].…”