Don’t Get Lateral View Chest Xrays to Diagnose Pneumothorax

June 21, 2010 The Trauma Pro Leave a comment

Pneumothorax is typically diagnosed radiographically. Significant pneumothoraces show up on chest xray, and even small ones will show up on CT.

Typically, a known pneumothorax is followed only with conventional chest xray. If the patient condition permits, these should be performed using the classic technique (upright, PA, tube 72" away). Unfortunately, physicians are used to ordering the chest xray as a bundle of both the PA and lateral views.

The lateral chest xray adds absolutely no useful information. The shoulder structures are in the way, and they obstruct a clear view of the lung apices, which is where the money is for detecting a simple pneumothorax. The xray below is of a patient with a small apical pneumothorax. There is no evidence of it on this lateral view.

Bottom line: only order PA views (or AP views in patients who can’t stand up) to follow simple pneumothoraces.

General

Chest tube collection system gone bad!

June 18, 2010 The Trauma Pro Leave a comment

This unit has been knocked over. Note the blood in both collection columns on the right. In this case, the water seal and pressure chambers have also been compromised (area on the left).

Collection systems that have been knocked over frequently malfunction and should be changed immediately! (It’s also impossible to accurately measure tube output after this happens)

Compromised collection system

Closeup of compromised system

General

Penetrating Injuries to the Extremities

June 16, 2010 The Trauma Pro Leave a comment

Simple penetrating injuries to the arms and legs are often over-treated with invasive testing and admission for observation. Frequently, these injuries can be rapidly evaluated and disposed of using physical examination skills alone.

Stabs and low velocity gunshots (no rifles or shotguns, please) should be thoroughly examined. This includes an examination of the entire, unclothed body. If this is not carried out, there is a risk that additional penetrating injuries may be missed.

For gunshots, look at the wounds and the estimated trajectory to try to demonstrate that the object stayed clear of neurovascular structures. This exam is imprecise, and must be accompanied by a full neurovascular exam and evaluation of the bones and joints. If there is any doubt regarding bony involvement, plain radiographs with entry markers should be performed. Any abnormal findings will require more in-depth evaluation and inpatient admission.

If the exam is negative but the trajectory is “in proximity” to a major vessel, an arterial pressure index (API) should be measured. This test involves the calculation of the ratio of the systolic pressure in the injured extremity to the contralateral uninjured extremity. It should not be confused with the ankle brachial index (ABI) which compares the systolic pressure in the ipsilateral uninjured arm or leg.

The magic ratio is 0.9. If the API is less than this, there is some likelihood that a vascular injury is present. If the API is higher, there is virtually no chance of injury.

The final test that must be performed before discharge is a function test. If the injured extremity is too painful to use or walk on, the patient may need to be admitted for pain management and therapy. Patients managed in this way can avoid arteriography, CT angiography or admission and save thousands of dollars in hospital charges.

Reference: Journal Am Coll Surgeons 2009;209:740-5.

General

Repeated Head CT Scans: Are They Really Necessary?

June 14, 2010 The Trauma Pro Leave a comment

There is an increasing public interest regarding exposure to medical radiation. It represents the major exposure source for the population at large. There may be a presumption on the part of medical providers that “what you can’t see can’t hurt you” but this is just not the case.

A number of studies have shown that there is risk association with repeated exposure to xray. This risk is particularly important when dealing with pediatric patients. It’s time to start critically looking at our imaging practices and to start critically thinking about every one that we order.

One common source of repeat radiation is the repetitive CT scans of the head that patients who suffer TBI undergo. Frequently, there is little rhyme or reason to the patter of these scans. Should we repeat in 6 hours? 24 hours? When any lesions finish evolving?

It turns out that there is a reasonable amount of guidance in the brain literature. For the most part, they suggest that patients who are not in an ICU only need a repeat CT if their mental status changes. Any others obtained did not result in any management change. The first 6 papers listed below agree with this.

However, number 7 is interesting. It was published in the Journal of the American College of Surgeons and was a retrospective study of patients seen at a Level I Trauma Center. All patients had a lesion seen on initial scan, and underwent repeat scanning. The authors found that 6% of their patients underwent a surgical or medical “intervention” based on changes on the repeat head CT. What troubled them the most was that 21 of these 51 patients did not have any substantial neurologic change. They conclude that routine repeat head CT is very useful.

It’s not clear why their results are so disparate from the others. It is retrospective, and the authors do not state what the interventions exactly are. Nor do they speculate on why their results are so different from others. Nor do they show any difference in outcomes.

The bottom line: Repeat head CT is probably not needed in patients with mild TBI who are not on anti-coagulants or anti-platelet agents. However, regular mental status checks and GCS measurements must be taken.

References:

Is repeated head computed tomography necessary for traumatic intracranial hemorrhage? American Surgeon 2005 Sep;71(9):701-4.
Routine repeat head CT for minimal head injury is unnecessary. J Trauma 2006, Mar;60(3):494-9.
A prospective evaluation of the value of repeat cranial computed tomography in patients with minimal head injury and an intracranial bleed. J Trauma 2006 Oct;61(4):862-7.
Indications for routine repeat head computed tomography (CT) stratified by severity of traumatic brain injury. J Trauma 2007 Jun;62(6):1339-44.
The role of early follow-up computed tomography imaging in the management of traumatic brain injury patients with intracranial hemorrhage. J Trauma 2007 Jul;63(1):75-82.
Value of repeat cranial computed tomography in pediatric patients sustaining moderate to severe traumatic brain injury. J Trauma 2008 Dec;65(6):1293-7.
Schedule repeat CT scanning for traumatic brain injury remains important in assessing head injury progression. J Amer Coll Surgeons 2010 May;210:824-32.

General

Pediatric ATV Injuries: A Look At The Data

June 9, 2010 The Trauma Pro Leave a comment

ATVs (all-terrain vehicles) are motor vehicles that are designed for use on uneven surfaces. Full-size ATVs can weigh up to 600 pounds and reach speeds of 75mph. There are up to 7 million ATVs currently being used in this country.

Unfortunately, young riders make up a disproportionate number of injuries and fatalities. About a third of all ATV-related deaths and ED visits involve riders under the age of 16. The risk factors for ATV injuries are well known:

No helmet
Risk-taking behaviors
Male (seems to go along with the previous one)
Large engine
Small child
3-wheeled ATVs
Driving on public roads
Riding with a passenger

The University of Connecticut published a recent study in which they surveyed youths at four major agricultural fairs covering the 4 major geographic areas of the state. The average age that the kids began riding was 9 years. The majority rode for fun, but more than a third admitted to racing informally with friends. 70% engaged in double-riding, 59% rode alone without family present, and 46% rode after dark. Most kids were trained on ATVs by family or friends, although 25% were self-taught. The majority wore appropriate clothing and 80% wore a helmet.

Nearly half of these kids admitted to being involved in at least one ATV crash. The most frequent type of crash was a rollover, followed by collision with a stationary object. 10% were pinned under the ATV. Commonly reported causes of the crash were poor driving conditions, lack of experience, and lack of strength to control the ATV. Those who reported crashing were also more likely to engage in risky ATV behavior like racing, riding after dark, riding without supervision, or riding a large ATV.

This study points to the need for additional education and training for both children who want to ride an ATV and their parents. The only way to reduce the number of children injured or killed by these vehicles is to make sure both groups understand the need for safe riding practices.

Reference: Campbell et al, J Pediatric Surg 45:925-929, 2010.

Home of the Trauma Professional's Blog