Fluid resuscitation and BP goals in trauma patients

Traditional trauma teaching advocated rapidly administering 1-2 litres of normal saline to the severe trauma patient in the resuscitative phase with the aim to maintain a near normal blood pressure.

It is increasingly recognised that infusing patients with large volumes of crystalloid can be detrimental

• Dilutes clotting factors
• Creates a dilutional anaemia
• Can elevate blood pressure sufficiently to create clot dislodgement and therefore cause more bleeding
• Worsens metabolic acidosis
• Creates hypothermia

 

Balanced transfusion – haemostatic resuscitation

There has been a shift now to using blood products early in hypovolaemic trauma patients. A balanced approach utilising red blood cells, platelets and plasma (in ratios of 1:1:1) has been shown to be of most benefit and is incorporated in most massive transfusion protocols.¹ Use of tranexamic acid has also been studied and is likely of benefit if utilised early.^2,3

 

Blood pressure goals

Blood pressure goals in trauma are less well defined. There has been a shift to accept a lower blood pressure (“permissive hypotension”) with the aim to prevent clot disruption in patients who have not had their injuries definitively managed.

There is limited strong evidence to support this approach. One semi-randomised study published in 1994 indicated that permissive hypotension might be of benefit in patients with penetrating torso trauma.⁴

Despite this, low volume trauma resuscitation has been adopted by many advanced trauma practitioners. Exact parameters have not been defined, but a SBP of 90 mmHg is commonly accepted in trauma patients with uncontrolled haemorrhage – so called “damage control resuscitation”.

A very important caveat to permissive hypotension is in patients with traumatic brain injury who need to have their cerebral perfusion pressure prioritised over the risk of clot disruption as it has been shown that even one episode of hypotension (SBP <90 mmHg) increases mortality.⁵

Caution also needs to be taken in patients with pre-existing hypotension or the elderly.

Other causes of hypotension (eg: tension pneumothorax) also need to be considered and addressed.

 

Viscoelastic haemostatic assay (VHA) guided resuscitation vs conventional coagulation testing (CCT)

Trauma‐induced coagulopathy is a derangement of haemostasis and thrombosis that develops rapidly and can be fatal if not corrected. viscoelastic haemostatic assays (thromboelastography [TEG] or rotational thromboelastometry [ROTEM]) have been developed to provide more rapid, accurate, and relatively comprehensive depictions of an individual’s coagulation profile compared with conventional coagulation testing. VHA’s may be used to augment or guide the transfusion strategy

 

A 2016 Cochrane Review⁷ concluded that TEG or ROTEM guided transfusion strategy may reduce need for blood products and improve mortality.  This was with the caveat that a large proportion of the trials included were cardiac surgical, with a low level of evidence.

 

A recent multi-centre European RCT⁶ compared outcomes in adult trauma patients receiving an empiric major haemorrhage protocol (MHP) supplemented by haemostatic therapy guided by either VHA or CCTs.  It did not show benefit of viscoelastic haemostatic assay augmented protocols when compared to conventional coagulation tests augmented protocols.  The role of VHA in major trauma patients remains uncertain.

 

Whole blood transfusion versus component therapy in adult trauma patients with acute major haemorrhage

Transfusion practice in NZ has evolved to blood component (component therapy) administered in a ratio to closely approximate whole blood (WB).   Using component blood reduces waste, increases storage times and allows a tailored approach to resuscitation.

However WB is currently increasingly being used in several international trauma systems.  Proponents of WB note that component therapy  is associated with a significantly anaemic, thrombocytopaenic, and coagulopathic product compared with whole blood, and cite several military studies suggesting a survival advantage of the early use of whole blood.  Systematic reviews and small observational studies have not shown a survival benefit in transfusing WB over component therapy ^8,9.  There is a currently a paucity of evidence supporting the optimal transfusion strategy in critically haemorrhaging trauma

 

References

1. Holcomb JB, Tilley BC, Baraniuk S, et al. Transfusion of plasma, platelets, and red blood cells in a 1:1:1 vs a 1:1:2 ratio and mortality in patients with severe trauma: the PROPPR randomized clinical trial. JAMA. 2015;313:(5)471-82.
2. Morrison JJ, Dubose JJ, Rasmussen TE, Midwinter MJ. Military application of tranexamic acid in trauma emergency resuscitation (MATTERs) study. Archives of surgery. 2012 Feb 20;147(2):113-9.
3. Williams-Johnson JA, McDonald AH, Strachan GG, Williams EW. Effects of tranexamic acid on death, vascular occlusive events, and blood transfusion in trauma patients with significant haemorrhage (CRASH-2): a randomised, placebo-controlled trial. West Indian Medical Journal. 2010 Dec;59(6):612-24
4. Bickell WH, Wall Jr MJ, Pepe PE, Martin RR, Ginger VF, Allen MK, Mattox KL. Immediate versus delayed fluid resuscitation for hypotensive patients with penetrating torso injuries. New England Journal of Medicine. 1994 Oct 27;331(17):1105-9.
5. Chesnut RM, Marshall LF, Klauber MR, Blunt BA, Baldwin N, Eisenberg HM, Jane JA, Marmarou A, Foulkes MA. The role of secondary brain injury in determining outcome from severe head injury. The Journal of trauma. 1993 Feb;34(2):216-22
6. Baksaas-Aasen K, et al. Viscoelastic haemostatic assay augmented protocols for major trauma haemorrhage (ITACTIC): a randomized, controlled trial. Intensive Care Med. 2020 Oct 13. doi: 10.1007/s00134-020-06266-1
7. Wikkelsø A, Wetterslev J, Møller AM, Afshari A. Thromboelastography (TEG) or thromboelastometry (ROTEM) to monitor haemostatic treatment versus usual care in adults or children with bleeding. Cochrane Database of Systematic Reviews 2016, Issue 8. Art. No.: CD007871.
8. Avery P, Morton S, Tucker H, et al. Whole blood transfusion versus component therapy in adult trauma patients with acute major haemorrhage.  Emergency Medicine Journal 2020;37:370-378
9. Duchesne et al. Single Institution Trial Comparing Whole Blood vs Balanced Component Therapy: 50 Years Later. Journal of the American College of Surgeons Vol 232, Issue 4,2021

 

See also

https://lifeinthefastlane.com/ccc/haemostatic-resuscitation/

https://lifeinthefastlane.com/ccc/permissive-hypotension/