Emerging
concepts and techniques Permissive hypotension
Also called hypotensive resuscitation, this concept is of increasing
interest to trauma surgeons faced with intra-abdominal or intrathoracic
haemorrhage. The important question is whether the systolic blood pressure
needs to be returned to premorbid levels utilising fluid resuscitation. In
nontrauma patients, vascular patients for example, controlled preoperative
hypotension is well established in certain situations. Further, recent
research in the USA seems to deprecate the use of rapid infusion systems (RIS),
with evidence emerging that large volume fluid resuscitation to achieve normal
systolic blood pressures is associated with increased mortality compared with
injured patients resuscitated with small fluid volumes prior to surgery. An
increasingly accepted view holds that moderate hypotension — systolic blood
pressure of 85—90 mmHg — is sufficient to maintain vital organ
perfusion and avoids a hypertensive overshoot with the risk of precipitating
further haemorrhage. The concept is still new in the care of the injured and
further trials on optimal fluids, levels of permissive hypotension and the
effects of delay before surgery are needed before it can be safely assimilated. The
most important message to retain is that the best treatment for ongoing
haemorrhage is to turn off the tap and not to continue infusion of fluids,
including blood products.
Damage
control — staged or abbreviated
laparotomy
The concept of staged operative procedures for the severely injured
patient is not new. The earliest uses of the approach
The
technical aspects of the procedure are dictated by the pattern of injuries. The
objectives are listed below.
Objectives
of staged or abbreviated laparotomy
• Arrest haemorrhage
• Control or limit coagulopathy
• Limit cavity contamination
• Protect viscera and limit fluid/protein loss
Having
achieved the objectives, the patient is returned to a critical care environment
for continuing monitoring, resuscitation and in-depth investigation prior to a
second definitive procedure. Moore terms this ‘physiological restoration in a
surgical intensive care unit’. Timing for the definitive procedure varies
but is usually within 24 hours of the damage-control procedure.
Focused
abdominal sonogram for trauma (FAST)
Portable, hand-held ultrasound is now being used by trauma surgeons in
the USA in the evaluation of patients with blunt thoracoabdominal trauma, and is
the preferred initial technological assessment of the patient. It belongs
early on in the secondary survey, although some centres advocate its use during
the ‘C’ component of the primary survey to localise intra-abdominal
haemorrhage and to rule out cardiac tamponade in overtly shocked patients
where no haemorrhage source is evident. The technique is rapid, with only four
areas being scanned at the initial investigation (Fig.
18.5). One of the
greatest challenges will be to train trauma surgeons in the use of the
technology.