Short-term effects of low-volume resuscitation with hypertonic saline and hydroxyethylstarch in an experimental model of lung contusion and haemorrhagic shock

Objectives: This study aimed to assess the short-term respiratory tolerance and haemodynamic efficiency of low-volume resuscitation with hypertonic saline and hydroxyethylstarch (HS/HES) in a pig model of lung contusion and controlled haemorrhagic shock. We hypothesised that a low-volume of HS/HES after haemorrhagic shock did not impact contused lungs in terms of extravascular lung water 3 hours after trauma. Methods: A lung contusion resulting from blunt chest trauma was induced in 28 anaesthetised female pigs with five bolt-shots to the right thoracic cage, followed by haemorrhagic shock and fluid resuscitation. Pigs were randomly allocated into two groups: fluid resuscitation by 4 ml/kg of HS/HES, or fluid resuscitation by 10 ml/kg of normal saline (NS). Monitoring was based on transpulmonary thermodilution and a pulmonary artery catheter. After 3 h, animals were euthanized to measure extravascular lung water (EVLW) by gravimetry. Results: Blunt chest trauma was followed by a transient collapse and hypoxaemia in both groups. Postmortem gravimetric assessment demonstrated a significant difference between EVLW in the NS-group (8.1 +/- 0.7 ml/kg) and in the HS/HES-group (6.2 +/- 0.6 ml/kg, P = 0.038). Based on a pathological EVLW threshold of > 7 ml/kg, results indicated that only the NS-group experienced moderate pulmonary oedema, contrary to the HS/HES-group. After haemorrhagic shock, HS/HES infusion enabled the restoration of effective mean arterial pressure and cardiac index. Intrapulmonary shunting increased transiently after fluid resuscitation but there was no significant impairment of oxygenation. Conclusion: In this pig model of lung contusion, the short-term assessment of fluid resuscitation after haemorrhagic shock with 4 ml/kg of HS/HES showed that pulmonary oedema was avoided compared to fluid resuscitation with 10 ml/kg of NS. (C) 2016 Societe franc aise d'anesthesie et de reanimation (Sfar). Published by Elsevier Masson SAS. All rights reserved.