Use of Abdominal CT in Stab Wounds to the Anterior Abdomen

February 2, 2010 The Trauma Pro Leave a comment

In general, stab wounds to the anterior abdomen (like any penetrating injury to the area) demand further evaluation to make sure there are no significant injuries. In the old days, a stab to the abdomen mandated a trip to the operating room. Fortunately, we recognized that more than half of these operations led to negative explorations.

Nowadays we can be much more selective. Here is my approach to evaluating these patients.

First, are there any indications that the patient needs to go to the OR right now?Check the vital signs. If there is any hemodynamic instability, operate! Check the abdomen. If there is obvious peritonitis, or significant tenderness more distant from the actual stab site, off you go to the OR!

Next, after finishing all of the usual ATLS protocol it’s time to evaluate further.Several options exist:

Observation – this is good for busy trauma centers that have lots of penetrating injury and busy ORs
DPL – not used too much any more, but certainly is legitimate. I recommend that your RBC count threshold be reduced to 25,000 or 50,000
Local wound exploration – this works in thinner people. Doing a LWE on an obese patient requires an incision that approaches the size of a small laparotomy. Might as well do it in the OR. Look for any violation of the anterior fascia.
CT scan – the new kid on the block

To use CT, the patient must be stable (remember, they should be in the OR if otherwise) and have had a full ATLS evaluation. They should also not be terribly thin. Too little fat makes it difficult to gauge depth of the injury.

The entry site(s) should be marked with a small marker to minimize streak artifact. Resist the temptation to just scan the area around the stab itself. Do a full IV contrast (no GI needed) abdomen/pelvis scan.

Look closely for blood outlining the wound tract. If it reaches the anterior abdominal fascia, the exam is positive. You do not need to see specific injury to the muscle or abdominal viscera. Violation of the anterior fascia is an absolute indication to proceed to the OR. On occasion, the knife will not penetrating the posterior fascia, or penetrates but does not injury any organs. In these cases it is best to have operated and found nothing rather than delaying and increasing the risk of intra-abdominal complications or infections.

Scan 1 shows blood tracking to the anterior fascia, as well as an increase in size of the rectus muscle.

Scan 2 shows penetration of the posterior rectus sheath with intra-abdominal fat herniating into it. The transverse colon is only 2 cm away deep to it. Scan 1 alone is enough to prompt you to take the patient to the OR!

General

A Quick and Dirty Test for Traumatic Brain Injury

February 1, 2010 The Trauma Pro Leave a comment

Traumatic brain injury (TBI) is an extremely common diagnosis in trauma patients. The majority are minor concussions that show no evidence of injury on head CT. Despite normal findings, however, a short conversation with the patient frequently demonstrates that they really do have a TBI.

Scoring systems can help quantitate how significant the head injury is. The Glasgow Coma Scale (GCS) score is frequently used. This scoring system is not sensitive enough for minor head injuries, since a patient may be perseverating even with a GCS of 15.

The Short Blessed Test (SBT) is a 25 year old scoring system for minor TBI that has been well-validated. It takes only a few minutes to administer, and is very easy to score.

The most important part of the administration process is choosing a threshold for further evaluation and testing. We administer this test to all trauma patients with a suspected TBI (defined as known or suspected loss of consciousness, or amnesia for the traumatic event). If the final score is >7, we refer the patient for more extensive evaluation by phsyical and occupational therapy. If the score is 7 or less but not zero, consideration should be given to offering routine followup in a minor neurotrauma clinic as an outpatient. In all cases, patients should be advised to avoid situations that would lead to a repeat concussion in the next month.

Download the Short Blessed Test instrument

Reference: Katzman R, Brown T, Fuld P, Peck A, Schechter R, Schimmel H. Validation of a short Orientation-Memory-Concentration Test of cognitive impairment. Am J Psychiatry. 1983 Jun;140(6):734-9.

General

Spine Immobilization in Penetrating Trauma: More Harm Than Good?

January 30, 2010 The Trauma Pro Leave a comment

The EMS standard of care for blunt trauma patients has been to fully immobilize the spine before transporting to an emergency department. This is such a common practice that it is frequently applied to victims of penetrating trauma prior to transport.

A recent study in the Journal of Trauma calls this practice in question, and suggests that it may increase mortality! The authors reviewed data in the National Trauma Data Bank, looking at information on penetrating trauma patients. They found that approximately 4% of these patients underwent spine immobilization.

Review of mortality statistics found that the mortality in non-immobilized (7%) doubled to 14% in the immobilized group!

The authors also found that medics would have to fail to immobilize over 1000 patients to harm one who really needed it, but to fully immobilize 66 patients who didn’t need it to contribute to 1 death.

Although this type of study can’t definitely show why immobilization in these patients is bad, it can be teased out by looking at related research. Even the relatively short delays caused by applying collars and back boards can lead to enough of a delay to definitive care in penetrating trauma patients that it could be deadly. The assumption in all of these patients is that they are bleeding to death until proven otherwise.

A number of studies have suggested that a “limited scene intervention” to prehospital care is best. The assumption is that the most effective treatment can only be delivered at a trauma center, so rapid transport with attention to airway, breathing and circulation is the best practice.

While interesting, some real-life common sense should be applied by all medics who treat these types of patients. The reality is that it is nearly impossible to destabilize the spine with a knife, so all stab victims can be transported without a thought to spine immobilization. Gunshots can damage the spine and spinal cord, so if there is any doubt that the bullet passed nearby, at least simple precautions should be taken to minimize spine movement.

Reference: Spine Immobilization in Penetrating Trauma: More Harm Than Good? Haut et al, Johns Hopkins. J Trauma 68(1): 115-121, 2010.

General

How To: Stop Scalp Bleeding

January 27, 2010 The Trauma Pro Leave a comment

Bleeding from scalp wounds may seem like a trivial problem, but I have personally seen someone die from unrecognized hemorrhage over time from one. All too often, these are covered up with a crude dressing when the patient arrives in the ED and is not looked at for some time.

Here are some tips to stop scalp bleeding:

Use direct pressure. This seems obvious but is frequently done incorrectly. Direct pressure involves a small diameter piece of gauze (stack of 2x2s or double folded 4×4) and only one or two fingers. Larger dressings or the palm of the hand do not provide enough pressure to stop all the bleeding. Direct pressure for 5 minutes (no peeking) will stop all bleeding that doesn’t need more advanced techniques.
Inject local anesthetic with epinephrine. This increases vasoconstriction and helps the direct pressure work even better. Be cautious if there is a large skin flap that does not have a nice pink color. Degloved skin has been crushed and small vessel vascular injury has occurred. Further reducing blood flow with epinephrine may kill the skin flap in this type of injury.
Apply Raney clips. Neurosurgeons use these to stop scalp bleeding during brain procedures. Caution! Only apply to unconscious patients, and only to the scalp (not face)! These hurt!
Oversew the scalp. Use a large silk or nylon suture and insert a large running stitch to close the wound. This will stop all bleeding from the skin edges. However, any arterial bleeders underneath will continue to be a problem.
Ligate individual bleeders. Use a small absorbable suture and attack each small arterial bleeder with a figure of 8 stitch. Don’t suture large chunks of tissue; make sure that you are attacking just the artery and not any adjacent nerves.

General

Initial Evaluation of Blunt Abdominal Trauma – Update

January 25, 2010 The Trauma Pro Leave a comment

This preliminary EAST Practice Management Guideline was presented and discussed at the 23rd Annual Scientific Assembly of the Eastern Association for the Surgery of Trauma.

The EAST practice guideline regarding evaluation of blunt abdominal trauma was first published in 2001. It was updated by performing a new literature search spanning 1998 to 2009. A total of 33 new articles were reviewed to provide material for the revised guideline. As usual, the number of high quality references (3 Class I and 11 Class II) were outnumbered by lower quality Class III references (19).

For information on classes of data and levels of recommendations, please refer to the Primer on Evidenced Based Medicine on the EAST website.

Important: These guidelines are preliminary and may undergo further minor revision, so the final version may be slightly different than described here!

The Level I recommendations remained basically the same, with one modification (bolded below):

FAST may be considered as the initial diagnostic modality to exclude hemoperitoneum.
Exploratory laparotomy is indicated in hemodynamically unstable patients with a positive FAST. In hemodynamically stable patients with a positive FAST, follow-up CT scan permits nonoperative management of select injuries.
Exploratory laparotomy is indicated for patients with a positive DPL and hemodynamic instability.

There was some interesting discussion about the continued utility of DPL. Some audience members felt that this was an outdated technique. Others pointed out that not all surgeons work in a Level I or II trauma center, and that FAST may not be available to them, so the technique remains relevant. Additionally, these guidelines may be used abroad where more advanced diagnostic testing is not as readily available, so it was recommended that the DPL language be retained.

The Level II recommendations are:

When DPL is used, clinical decisions should be made on the basis of the presence of gross blood on initial aspiration (i.e. 10ml) or microscopic analysis of lavage effluent.
Surveillance studies (i.e. DPL, CT scan, repeat FAST) should be considered in hemodynamically stable patients with indeterminate FAST results.
CT scanning is recommended for the evaluation of hemodynamically stable patients with equivocal findings on physical examination, associated with neurologic injury, or multiple extra-abdominal injuries. Under these circumstances, patients with a negative CT should be admitted for observation.
CT scanning is the diagnostic modality of choice for nonoperative management of solid visceral injuries.
In hemodynamically stable patients, DPL and CT scanning are complementary diagnostic modalities.
Contrast enhanced ultrasound (CEUS) is more sensitive than non-contrast ultrasound in the detection of solid organ injury. Many members of the audience were not familiar with this technique. I will comment on it in a later blog entry.
In the patient at high risk for intra-abdominal injury (e.g. multiple orthopedic injuries, severe chest wall trauma, neurologic impairment) a CT scan should be considered in hemodynamically stable patients, even after a negative FAST.

Finally, the Level III recommendations are:

Objective testing (i.e. FAST, DPL, CT scanning) is indicated for patients with abnormal mentation, equivocal findings on physical examination, multiple injuries, concomitant chest injury, or hematuria.
Patients with seat belt sign should be admitted for observation and serial physical examination. The presence of intraperitoneal fluid on FAST or CT scan in a patient with seat belt sign suggests the presence of an intra-abdominal injury that may require surgery.
CT scanning is indicated for suspected renal injuries.
In hemodynamically stable patients with a positive DPL, a CT scan should be considered, especially in the presence of pelvic fracture or suspected injuries to the genitourinary tract, diaphragm or pancreas.
Patients with free fluid and no solid organ injury on CT should be considered for laparotomy. Alternatively, laparoscopy or DPL may aid in diagnosis of bowel injury. Patients with no head injury and clear mentation may be followed by serial exams.

Home of the Trauma Professional's Blog