Metabolic Failure

Hypothermia. Acidosis. Coagulopathy. These three derangements become established quickly in the exsanguinating trauma patient and, once established, form a vicious circle which may be impossible to overcome.

Damage Control Surgery

Overview
Metabolic failure
Damage control laparotomy
Organ-specific techniques
Critical Care
Abdominal Compartment Syndrome
Reoperation

Hypothermia
The majority of major trauma patients are hypothermic on arrival in the emergency department due to environmental conditions at the scene. Inadequate protection, intravenous fluid administration and ongoing blood loss will worsen the hypothermic state. Haemorrhagic shock leads to decreased cellular perfusion and oxygenation and so inadequate heat production. Hypothermia has dramatic systemic effects on the bodies functions but most importantly in this context exacerbates coagulopathy and interferes with blood homeostatic mechanisms.

Acidosis
Uncorrected haemorrhagic shock will lead into inadequate cellular perfusion, anaerobic metabolism and the production of lactic acid. This leads to profound metabolic acidosis which also interferes with blood clotting mechanisms and promotes coagulopathy and blood loss.

Coagulopathy
Hypothermia, acidosis and the consequences of massive blood transfusion all lead to the development of a coagulopathy. Even if control of mechanical bleeding is achievable, patients may continue to bleed from all cut surfaces. This leads to a worsening of haemorrhagic shock and so a worsening of hypothermia and acidosis, prolonging the vicious cycle.

Some studies have attempted to place threshold levels on these parameters. Some state that conversion to a damage control procedure should take place if the pH is below 7.2, core temperature is below 32C or the patient has received more than one blood volume transfusion. However, once these levels are reached, it is already too late.

The trauma surgeon must make the decision to convert to a limited procedure within 5 minutes of starting the operative procedure. This decision is made on the initial physiological state of the patient and the rapid initial assessment of internal injuries. Do not wait for metabolic failure to set in. This early decision is imperative to the patients survival.

Damage Control Laparotomy