202501041555

Status:

Tags: Trauma

Abdominal trauma

Acute traumatic coagulopathy (ATC) describes the phenomenon of direct shock-induced haemostatic deficit.
Acute traumatic coagulopathy appears to be driven initially by severe tissue damage, shock-related hypoperfusion and an inflammatory response leading to the activation of anticoagulant pathways, fibrinolytic pathways and platelet dysfunction

Trauma-induced coagulopathy (TIC) describes the multifactorial coagulopathy associated with trauma including ATC plus dilution, hypothermia, acidosis and other factors
Trauma-induced coagulopathy develops in around one-third of patients with traumatic bleeding; its incidence correlates with increasing severity of injury

The first step in rehabilitation from trauma (returning an individual to their functional state before the injury) is the acute resuscitative phase where the objectives are to

The central components of DCR (damage control resus) are:

  1. #Damage-control surgery (DCS)
  2. #Permissive hypotension
  3. #Blood product resuscitation

Certain characteristics have been proposed to identify patients who may benefit from DCR:

Damage-control surgery

originally defined as ‘initial control of haemorrhage and contamination followed by intraperitoneal packing and rapid closure’ to facilitate restoration of physiology in the ICU and later definitive surgery

For control of haemorrhage, surgical manoeuvres may include

Reperfusion syndrome including vasoplegia, arrhythmias and hyperkalaemia may be encountered after restoration of flow such as release of clamps, repair of vessels or deflation of REBOA

Control of contamination may involve drainage in biliary, duodenal or pancreatic injury, stapled resection of injured gastrointestinal segments, and deferring of anastomosis or stoma

Temporary abdominal closure is common and facilitates easy re-entry, preservation of fascia for later definitive closure and reduces the likelihood of abdominal compartment syndrome

Elements of DCS
Indications

Definitive repair is undertaken after correction of shock, acidosis, hypothermia, coagulopathy and anaemia, occurring 24–48 h later depending on the patient's condition and organisational capacity

Multiple repeat laparotomies may be required. About 30–60% of patients cannot be closed at this time because of visceral oedema and fascial retraction, requiring a subsequent procedure

Permissive hypotension

In the patient in haemorrhagic shock with a significantly ↓ circulating volume, relatively small volumes of crystalloid or colloid solutions can cause significant haemodilution

current evidence suggests that permissive hypotension is safe and confers a mortality benefit alongside ↓ in blood loss and usage

Hypotension is not a therapeutic target in itself but, for example, the literature describes the acceptance of

Increasing SVR, although improving arterial pressure, is often counterproductive to resuscitation targets as increased arterial pressure correlates with increased bleeding and risks destabilising newly formed clot, and therefore vasopressor drugs are generally avoided

When bleeding is ongoing, attempts to use volume resuscitation to restore preload, cardiac output, perfusion and thus BP are futile, may increase bleeding because of higher venous pressure, and result in large volumes infused with little benefit. This is classically described as the transient- or non-responder

patients who can sustain, for example, a MAP of 65 mmHg after volume resuscitation without vasopressors, are unlikely to be actively bleeding and BP and perfusion can be managed as per the anaesthetist's usual practice

Inevitably present are the dilutional effects of even balanced blood product use and the inflammatory effects of allogenic blood transfusion, in addition to an increased risk of post-injury infection and multiorgan failure, and the usage of a precious resource

The tolerated duration of permissive hypotension is often quoted as 1 h, as animal models show that the physiological deterioration and metabolic acidosis caused by tissue hypotension are still reversible with a return to normotensive resuscitation by this time

Hypotension is harmful in TBI, but haemorrhage control takes precedence as the end point of uncontrolled haemorrhage will be death regardless of the neurological status.

Blood product resuscitation

early use of PRBCs and FFP, followed by later addition of platelets and cryoprecipitate as a replacement source of fibrinogen

Fresh frozen plasma is given in a 1:1 ratio with PRBCs so as not to worsen TIC by causing a dilutional coagulopathy

TXA is given using an initial bolus of 1 g, followed by a subsequent 1 g infusion over 8 h

Major trials:

PROPPR
1:1 PRBCs and FFP ratio use reduces death from exsanguination, but not overall mortality in 24 h, without an increase in transfusion-related complications

PROCOAG
Four-factor prothrombin complex concentrate does not decrease 24-h blood product consumption and causes an increase in thromboembolic complications

CRYOSTAT-2
Early empirical high-dose cryoprecipitate does not reduce 28-day mortality

CRASH-2
Tranexamic acid reduces mortality in trauma if given within 3 h

Hypothermia adversely affects coagulation by causing

Blood gas analysis should be performed frequently (e.g. Q15 min) during resuscitation

Hyperkalaemia becomes increasingly common as transfusion ensues, probably because of the potassium content of PRBCs and its release from damaged and ischaemic tissues

Calcium plays an important role in trauma, mitigating the effects of potassium on cardiac conduction and contractility. It also has critical roles in vascular tone, and haemostasis including on platelet activation and adhesion, and as an enzyme cofactor

Paradoxically, the acidosis associated with shock causes displacement of calcium from albumin and increases free ionised calcium concentrations, but this is not enough to mitigate loss and maldistribution.

Haemodynamic effects are apparent at serum Ca2+ concentrations <0.8 mmol/L and effects on clotting at concentrations <0.56 mmol/L

Approximately 10 mmol calcium chloride is needed for every 4–6 units of PRBCs.

No good evidence supporting use of NaHCO3
Tris-hydroxymethyl amino methane (THAM) is an alternative buffer that may avoid these issues but is not currently used in the UK

VHA:
iTACTIC study reported no improvement in patients alive and free of massive transfusion at 24 h with VHA compared with fixed-ratio therapy guided by conventional coagulation tests (CCTs). Conversely, other studies have shown benefit, with decreased mortality and massive transfusion rate at 24 h, decreased use of blood components and decreased costs with VHA

Pre-op / at A&E

based on ATLS

The roles of the anaesthetist include

Induction of anaesthesia is usually best deferred to the operating theatre

Venous access should be high-flow and above the diaphragm because the continuity of the vasculature with the heart may be disrupted below this in trauma

Clinicians should be aware that certain conditions may mimic the physiological presentation of haemorrhage including cardiac tamponade, TBI and spinal cord injury, whereas the catecholamine response will compensate for and obscure evidence of bleeding, particularly in young and healthy patients.

CT vs IR vs OT

The hallmark of an effective surgical pathway is the ability to bypass CT and make use of this time in the operating theatre for patients who are haemorrhaging and in extremis

All the major locations of bleeding (chest, abdomen, pelvis, retroperitoneum and external haemorrhage) can be definitively explored operatively, with capacity to immediately intervene.

In addition to identifying bleeding sources and concurrent injury including brain and spinal cord trauma, CT can also identify pathology potentially amenable to angioembolisation

Abdominal injuries amenable to an IR-only strategy include active arterial pelvic or solid organ (spleen, liver or kidney) haemorrhage. Arterial haemorrhage that involves junctional or challenging surgical locations may be amenable to a joint IR/surgery approach

Exploratory laparotomy remains the gold standard for patients with

Contrast-enhanced CT of the chest, abdomen and pelvis is the definitive modality in this patient group, with non-contrast head and neck, and arterial-phase neck and limb imaging as indicated by the pattern of injury

BASTE mnemonics

Intra-op

Preparation

Equipment

Induction

In severely unwell patients, surgeons should be scrubbed and ready for immediate knife to skin as even optimal induction may still lead to instability

Blood products should be ready to give via a rapid infusion device facilitating ongoing resuscitation during induction to prevent cardiovascular collapse

A key consideration during induction of anaesthesia is avoiding hypotension and cardiac arrest

sudden increases in arterial pressure are also undesirable, as they may restart bleeding or worsen any intracranial injury

In addition to any ongoing bleeding, hypotension on induction may be secondary to

Major haemorrhage influences the pharmacokinetics of i.v. anaesthetic agents, with animal models showing ↑ plasma drug concentrations with equivalent dosing.
in practice, this means that dose effects may be unpredictable and significant reductions may be necessary to avoid haemodynamic compromise.

Ketamine is the preferred induction agent in trauma because of its relative cardiovascular stability and longer duration of effect

Fentanyl blunts the response to laryngoscopy but also sympathetic drive causing hypotension

Some clinicians advocate for ↑ doses of rocuronium to shorten the prolonged onset times associated with shock.

In the awake, less compromised trauma patient without intracranial injury, a 1:1:1 combination of fentanyl 1 μg/kg, ketamine 1 mg/kg and rocuronium 1 mg/kg is effective. In a shocked patient, this is adjusted to rocuronium 1–2 mg/kg with ketamine 0.5–1 mg/kg, omitting fentanyl. In near- or actual cardiac arrest, further dose reduction or even omission may be appropriate.

Airway in trauma

expecting Difficult airway & need of eFONA
may need MILS

To mitigate haemodynamic effects from the switch to positive pressure ventilation, begin with

Maintenance

Given the altered pharmacology of propofol in haemorrhage, anaesthesia is maintained with a volatile agent such as sevoflurane

Fentanyl, starting in 50μg aliquots and increased as tolerated often to total doses of 15–25 μg/kg, will allow a considerable reduction in MAC of sevoflurane, typically to 0.5

Depth of anaesthesia monitoring may provide reassurance.

may need to repeat TXA & Abx due to haemorrhage

Post-op

intubated to ICU

After surgery, the aim is for resolution of

Key points of Critical care management

?Possibility of applying ERAS elements to non extremis patients

Analgesia

multimodal
IV PCA
paracetamol
NSAIDs
RA (e.g. rectus sheath catheters)
low dose ketamine

References

Anaesthetic management of abdominal trauma - BJA Education
Anaesthetic Management of Abdominal Trauma - BJA Ed

Acute Traumatic Coagulopathy Pathophysiology and Resuscitation - BJA

Trauma-Induced Coagulopathy - Nature

Trauma Induced Coagulopathy