Resuscitation (2007) 72, 371—378 CLINICAL PAPER Decreased fluid volume to reduce organ damage: A new approach to burn shock resuscitation? A preliminary studyଝ S. Arlati ∗, E. Storti, V. Pradella, L. Bucci, A. Vitolo, M. Pulici Intensive Care Unit ‘‘G. Bozza’’, Niguarda Ca-Granda` Hospital, Piazza Ospedale Maggiore 3, 20162 Milan, Italy Received 28 March 2006; received in revised form 23 June 2006; accepted 14 July 2006 KEYWORDS Summary Burn injury; Objective: To evaluate the impact of decreased fluid resuscitation on multiple- Shock; organ dysfunction after severe burns. This approach was referred to as ‘‘permissive Resuscitation; hypovolaemia’’. Fluid therapy; Methods: Two cohorts of patients with burns >20% BSA without associated injuries Haemodynamics and admitted to ICU within 6 h from the thermal injury were compared. Patients were matched for both age and burn severity. The multiple-organ dysfunction score (MODS) by Marshall was calculated for 10 days after ICU admission. Permissive hypo- volaemia was administered by a haemodynamic-oriented approach throughout the first 24-h period. Haemodynamic variables, arterial blood lactates and net fluid balance were obtained throughout the first 48 h. Results: Twenty-four patients were enrolled: twelve of them received the Parkland Formula while twelve were resuscitated according to the permissive hypo- volaemic approach. Permissive hypovolaemia allowed for less volume infusion (3.2 ± 0.7 ml/kg/% burn versus 4.6 ± 0.3 ml/kg/% burn; P < 0.001), a reduced posi- tive fluid balance (+7.5 ± 5.4 l/day versus +12 ± 4.7 l/day; P < 0.05) and significantly lesser MODS Score values (P = 0.003) than the Parkland Formula. Both haemodynamic variables and arterial blood lactate levels were comparable between the patient cohorts throughout the resuscitation period. Conclusions: Permissive hypovolaemia seems safe and well tolerated by burn patients. Moreover, it seems effective in reducing multiple-organ dysfunction as induced by oedema fluid accumulation and inadequate O2 tissue utilization. © 2006 Elsevier Ireland Ltd. All rights reserved. ଝ A Spanish translated version of the summary of this article appears as Appendix in the final online version at Introduction doi:10.1016/j.resuscitation.2006.07.010. ∗ Corresponding author. Tel.: +39 264442469/2470; fax: +39 264442908. Resuscitation from burn shock is a formidable E-mail addresses: [email protected] (S. Arlati), challenge for intensive care specialists. The exten- [email protected] (L. Bucci). sive capillary damage which follows thermal injury 0300-9572/$ — see front matter © 2006 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.resuscitation.2006.07.010 372 S. Arlati et al. is responsible for massive plasma extravasation that allowed for sufficient vital organ perfusion, into burned tissues with consequent hypovolaemia while at the same time avoiding any resuscitation and shock.1—3 Too vigorous resuscitative efforts delay. This approach was referred to as permis- may lead to severe protein depletion with fur- sive hypovolaemia. We also hypothesised that if ther oedema accumulation into both burned and the deliberate reduction of resuscitation volume unburned tissues. In the past decades several could allow for decreased extravasation of flu- formulae have been developed for optimal fluid ids, then less multiple-organ dysfunction might be resuscitation of burn patients, the most popular anticipated as consequence of reduced oedema for- being the Parkland Formula.4 This time-honoured mation. Therefore, the present study evaluates the approach allows for sufficient vital organ perfusion, effectiveness of permissive hypovolaemia in reduc- while avoiding excessive oedema formation. ing multiple-organ dysfunction as compared with Although adequate resuscitation has long been the Parkland Formula. recognised as the single most important ther- apeutic intervention of burn critical care, the routine use of invasive haemodynamic monitor- Methods ing has never been recommended as guide for fluid volume replacement by fear of infections. The study was performed in accordance Nowadays, the adequacy of resuscitative efforts with guidelines laid down by the hospital is still assessed by a combination of both tradi- ethics committee tional and semi-invasive variables, the insertion of a pulmonary artery catheter being restricted to Two cohorts of patients were compared. Twelve patients with refractory shock or limited cardiopul- patients resuscitated with permissive hypovolaemia monary reserve.5 In recent years, the introduction and admitted to our eight general ICU beds from of trans-pulmonary indicator dilution technique at January 2004 to December 2005 were matched with the bedside has made the use of invasive haemo- 12 patients receiving the Parkland Formula in the dynamic monitoring in burned patients easier.6—8 two preceding years. Patients were enrolled only Its reduced invasiveness as compared with pul- if they were equipped with the PiCCO© system monary artery catheterisation9 and the possibility (Pulsion Medical System, Munich, Germany) thus of direct cardiac preload estimation10 also allowed allowing for both ITBV and cardiac output mea- for a haemodynamic-oriented approach to burn surements. Other admission criteria were age >14 shock resuscitation.6 Since 2000, we routinely use years, burn size ≥20% BSA, absence of concomitant both intrathoracic blood volume (ITBV) and cardiac injuries and ICU admission within 6 h of the ther- output measurement as earlier and more sensitive mal insult. Exclusion criteria were inhalation injury indicators of critical hypovolaemia than vital signs, as confirmed by bronchoscopy, pre-existing med- hourly urine output and central venous pressure. ical illnesses compromising the cardiopulmonary The trans-pulmonary indicator dilution technique reserve and need for compassionate care only. enabled us to appreciate that the Parkland For- As cardiovascular reserve and trauma severity are mula did not allow for the early (<24 h) correction of important determinants of multiple-organ dysfunc- intravascular volume deficit as complete ITBV nor- tion, the makeup of both cohorts was matched malisation could only be achieved after the first for age, total burns size and depth thus provid- 48 h post-burn. Additionally, a condition of fluid ing an accurate comparison of the two infusion unresponsiveness was present throughout the first regimens that was not affected by these fac- 12-h period, any increase of the administered fluids tors. Additionally, patients receiving the Parkland only accelerating post-burn oedema accumulation. Formula were included only if their actual resus- In a recent study, the rate of intravascular volume citation volume was lesser than 5 ml/kg/% burn. replacement was found to be independent from The different impact of permissive hypovolemia the amount of crystalloid infused as the admin- and the Parkland Formula on multiple-organ dys- istration of supranormal volumes failed into the function was our primary study end-point. The early (24 h) achievement of normal preload and DO2 multiple-organ dysfunction score (MODS) by Mar- values.8 We therefore speculated that the adoption shall et al. was used to assess the severity of organ of a reduced rather than aggressive approach was function impairment.11 The score was calculated preferable as the potential existed for decreased on a daily base for 10 consecutive days. Cardiac oedema formation, provided that resuscitation was preload as assessed by thermo-dilution derived not delayed. Since 2004, we therefore reduced ITBV measurement and continuous cardiac out- the volume given as low as possible by titrat- put monitoring by femoral arterial thermo-dilution ing the infusion rate to a minimum ITBV value calibrated pulse contour analysis12 were obtained Decreased fluid volume to reduce organ damage 373 throughout the first 48 h period. The severity of tis- fluid volume calculated as follows: [1500 ml × BSA sue hypoperfusion was assessed by arterial blood (m2)] + [3750 ml × BSA (m2) × (%burn/100)]. The lactate measurements. Systemic vascular resis- maintenance fluid volume was given as 50% nor- tance (SVR), ventricular stroke volume (SV) and mal saline in 5% dextrose solution. According to 13 global oxygen delivery (DO2) were calculated using the practice guidelines for burn care, success- standard formulae and indexed to body surface ful resuscitation was achieved when no further area, thus allowing for inter-individual compari- oedema fluid accumulation occurred, this in prac- son. Daily urine output was recorded and expressed tice meaning that a neutral balance was achieved as ml/kg/day. Daily evaporative losses were esti- between actual and maintenance fluid volume. mated according to the formula: [3750 ml × BSA Patients with severe plasma protein depletion (m2) × (% burn/100)]: thus an adult of 2 m2 with a (<3.5 g/dl) received 20% albumin in saline solution 20% burn extension had a calculated water loss of after the first 24 h post-burn. Fresh frozen plasma 3750 ml × 2 × 0.20 = 1500 ml/day. Net fluid balance and packed red cells were utilized as appropriate. was calculated as the algebraic sum of the total volume given minus the daily urine output and evap- Data analysis orative water losses. The fluids administered before ICU admission were included into the calculations The area under curve (AUC) of the daily MODS of the total resuscitation volume. score was calculated throughout the first 10 days after ICU admission and also used for analysis.14 Resuscitation