All posts by TheTraumaPro

How Good Is The Spine Exam In Penetrating Injury?

Examination of the spine in trauma patients is typically not very helpful. We always look for stepoffs. swelling and tenderness, but the correlation with actual injury is poor. A recent paper presented at the American Medical Student Association Annual Convention showed that it actually can be helpful in victims of penetrating injury.

A prospective study of 282 patients was carried out at a Level I Trauma Center, specifically focusing on penetrating trauma. Half had gunshot wounds, and 8% sustained spinal injury with one third left with permanent disability. Stab wounds never led to a spinal cord injury. The most common patterns for cord injury in gunshot wounds was a single shot to the head or neck, or multiple shots to the torso. 

The examiners looked for pain, tenderness, deformity and neurologic deficit. They found that the sensitivity was 67%, the specificity was 90%, the positive predictive value was 95% and the negative predictive value was 46%. These numbers are much better than those found during spine examination after blunt trauma. They also determined that prehospital immobilization after penetrating injury would not have helped, which I have also written about here.

The bottom line: a good spine exam in victims of penetrating trauma can accelerate definitive management prior to defining the exact details of the injury with radiographic or MRI imaging. This is particularly helpful in patients who present to non-trauma centers, where imaging or image interpretation may not be readily available. 

Reference: American Medical Student Association (AMSA) 60th Annual Convention: Abstract 26: Presented March 11, 2010

Is It Safe to Watch Occult Pneumothorax in Ventilated Patients?

An occult pneumothorax is one that is visible on chest CT but not conventional chest xray. The pneumo can be a single bubble, or it can be a larger one that layers out over the lung but cannot be seen on plain xray. This air is generally watched for a period of time, typically 6 hours, then a repeat plain radiograph is obtained to see if it has become visible. 

The pneumothorax literature cautions us about watching visible pneumothoraces in patients who are placed on positive pressure ventilation. The rationale is that this may force more air out of an acutely injured lung, resulting in an enlarging pneumothorax. Many have recommended that a chest tube be placed in any patient with a visible pneumothorax on positive pressure ventilation to avoid the possibility of developing a tension pneumothorax.

But what about the occult pneumothorax? Since they are generally very small, do they pose the same risk? A paper from 2008 retrospectively reviewed 79 patients with occult pneumothorax , 20 of whom were placed on ventilators. 51 of 59 of the non-ventilated patients had no change in their occult pneumo (86%), while 16 of 20 of the ventilated patients had no progression (80%).

The study numbers are small, but suggest that occult pneumothoraces can be safely watched. The real question is, how long do you have to watch it? Typically, ventilated patients get regular chest xrays, so monitoring for progression of the pneumo should be easy.

Reference: American Surgeon 74(10):958, 2008.

Lack of Insurance in Trauma Patients Increases Mortality

A recent research article from the LAC+USC Level I trauma center in Los Angeles looked at the impact of insurance vs no insurance on outcomes after trauma. They reviewed 8 years of admissions starting in 1998. The outcomes analyzed included mortality, operative procedures, radiographic studies, and length of stay. Nearly 30,000 admission records were reviewed.

Some interesting findings:

  • Insured patients were generally older, victims of blunt trauma, and were significantly more severely injured
  • More procedures and radiographic studies were performed in the insured group (may be due to severity of injury)
  • ICU length of stay was longer in the insured patients (may be due to severity of injury)
  • Mortality was increased in uninsured patients. This difference was most pronounced in African American and Hispanic patients

The relationship between insurance status and access to healthcare has been investigated by numerous groups, but generally in the context of access to health resources. The major effect of lacking insurance in those studies is decreased access and subsequently poorer general health. 

The current study looked at a new population: trauma patients at an urban, county-based Level I trauma center that provides equal access to care regardless of payor status. In theory, insurance status has no bearing on access in these patients. The most notable finding was that uninsured patients had a significantly higher mortality despite younger age and lower injury severity. This was most pronounced in African American and Hispanic patients. 

The reasons for these disparities is unclear. Perhaps lack of access to regular healthcare resulted in nutritional problems or disorders due to alcohol or drug use. There may also be a relationship to an increased involvement in penetrating trauma. 

Overall, the relationship between insurance status and outcome after trauma is complex. Access to basic healthcare coverage may affect chronic health status and the ability to survive serious injury. It may also be an indicator of other factors that have not yet been determined. It certainly provides food for thought as the country increases access to basic healthcare for people who have not previously been able to obtain it.

Reference: J Trauma 68(1):211-216, 2010.

Trauma 20 Years Ago: Colon Injury

Through the 1970’s and 80’s, a colon injury was automatically managed by repair/resection coupled with a diverting colostomy. This technique became commonplace due to bad experiences with repair attempts during earlier decades.

During the late 70’s, a few trauma centers began dabbling in primary repair. At Wayne State University in Detroit, John Kirkpatrick had popularized an exteriorization technique. This involved repairing the colon and bringing the area of repair to the outside of the body. The area was watched for several days and if no breakdown was noted, it could be dropped back into the abdomen with a relatively minor procedure. 

After the success of exteriorization, some of the surgeons at Receiving began repairing colon injuries and leaving them in the abdomen. They retrospectively looked at their experience with this radical idea from 1980 to 1987. Injuries were predominantly penetrating. From 1980 to 1983, 29% of patients were managed in this way. During the final years, the use of this technique increased to 56%. 

Interestingly, Injury Severity Score in patients who did not get colostomy was higher, but the number of complications (leaks, intra-abdominal abscesses) was lower! Colostomy patients had 15 abscesses, while those without colostomy had 1 leak and only 5 abscesses.

This paper represents one of the first reports on colon injury management without colostomy, and set the stage for additional trials. It has led to the nearly routine use of this technique in current times.

Reference: Management of the Injured Colon: Evolving Practice at an Urban Trauma Center. Levison, Thomas, Wiencek and Wilson. J Trauma 30(3): 247-253, 1980.

The Right Way to Treat Tension Pneumothorax

Tension pneumothorax is an uncommon but potentially lethal manifestation of chest injury. An injury to the lung occurs that creates a one-way valve effect, allowing a small amount of air to escape with every breath. Eventually the volume becomes so large as to cause the lung and mediastinum to push toward the other side, with profound hypotension and cardiovascular collapse.

The classic clinical findings are:

  • Hypotension
  • Decreased or absent breath sounds on the affected side
  • Hyperresonance to percussion
  • Shift of the trachea away from the affected side
  • Distended neck veins

You should never diagnose a tension pneumothorax with a chest xray or CT scan, because the diagnosis is a clinical one and the patient may die while these procedures are carried out. Having said that, here’s one:

Tension Pneumothorax

The arrow points to the completely collapsed lung. Note the trachea bowing to the right. 

As soon as the diagnosis is made, the right thing to do is to “needle the chest.” A large bore angiocath should be placed in the second intercostal space, mid-clavicular line, sliding right over the top of the third rib. The needle should then be removed, leaving the catheter.

The traditional large bore needle is 14 gauge, but they tend to be short and flimsy. They may not penetrate the pleura in an obese patient, and will probably kink off rapidly. Order the largest, longest angiocath possible and stock them in your trauma resuscitation rooms.

image

The top catheter in this photo is a 14 gauge 1.25 inch model. The bottom (preferred at Regions) is a 10 gauge 3 inch unit. Big difference! And if the patient is extremely obese, make a 1 cm cut in the skin and sink the hub deep to the skin for extra distance.

The final tip to treating a tension pneumothorax is that a chest tube must be placed immediately after inserting the needle. If the patient is on a ventilator, the positive pressure will slowly expand the lung. But if they are breathing spontaneously, the needle will change the tension pneumothorax into a simple open pneumothorax. Patients with other cardiovascular problems will not tolerate this for long and may need to be intubated if you dawdle.