Category Archives: General

Flying After Pneumothorax

September 20, 2010 The Trauma Pro Leave a comment

Patients who have sustained a traumatic pneumothorax occasionally ask how soon they can fly in an airplane after they are discharged. What’s the right answer?

The basic problem has to do with Boyle’s Law (remember that from high school?). The volume of a gas varies inversely with the barometric pressure. So the lower the pressure, the larger a volume of gas becomes. Most of us hang out pretty close to sea level, so this is not an issue.

However, flying in a commercial airliner is different. Even though the aircraft may cruise at 30,000+ feet, the inside of the cabin remains considerably lower though not at sea level. Typically, the cabin altitude goes up to about 8,000 to 9,000 feet. Using Boyle’s law, any volume of gas (say, a pneumothorax in your chest), will increase by about a third on a commercial flight.

The physiologic effect of this increase depends upon the patient. If they are young and fit, they may never know anything is happening. But if they are elderly and/or have a limited pulmonary reserve, it may compromise enough lung function to make them symptomatic.

Commercial guidelines for travel after pneumothorax range from 2-6 weeks. The Aerospace Medical Association published guidelines that state that 2-3 weeks is acceptable. The Orlando Regional Medical Center reviewed the literature and devised a practice guideline that has a single Level 2 recommendation that commercial air travel is safe 2 weeks after resolution of the pneumothorax, and that a chest xray should be obtained immediately prior to travel to confirm resolution.

Bottom line: Patients can safely travel on commercial aircraft 2 weeks after resolution of pneumothorax. Ideally, a chest xray should be obtained shortly before travel to confirm that it is gone. Helicopter travel is okay at any time, since they typically fly at 1,500 feet or less.

References:

Practice Guideline, Orlando Regional Medical Center. Air travel following traumatic pneumothorax. October 2009.
Medical Guidelines for Airline Travel, 2nd edition. Aerospace Medical Association. Aviation, Space, and Environmental Medicine 74(5) Section II Supplement, May 2003.

General

To Probe or Not To Probe: Penetrating Wounds

September 14, 2010 The Trauma Pro Leave a comment

There is considerable variability in the way that penetrating wounds are approached. Some are located over areas of lesser importance (distal extremities) or are so superficial that they obviously don’t fully penetrate the skin.

Unfortunately, some involve high-value structures (much of the neck and torso), or are too small to tell if they penetrate (ice pick injury). How should these injuries be approached?

Too often, someone just probes the wound and makes a pronouncement based on that assessment. Unfortunately, there are major problems with this technique:

The tract may be too small to appreciate with a finger or even a cotton-tip swab
The tract may be oriented in an unexpected direction, or the soft tissues may have moved after the penetration occurred. In this case, the examiner may not appreciate any significant depth to the wound.
Inserting an object may violate a structure that you wish it hadn’t (resulting in a hissing sound after probing a chest wound, or a column of blood after probing the neck)

A better way to approach these wounds is as follows:

Is the patient unstable? If so, you know the penetration caused the problem and the patient belongs in the OR.
Is there other evidence of deep injury, such as peritonitis with a penetrating abdominal wound? If so, the patient still needs to go to the OR.
Do a legitimate local wound exploration. This entails making the hole bigger with a knife, and using surgical instruments and your eyes to find the bottom of the tract. Obviously, there are some parts of the body where this cannot be done, such as the face, but they probably don’t need this kind of workup anyway.

As one of my mentors, John Weigelt, used to say, “Doctor, do you have an eye on the end of your finger?” In general, don’t use anything that doesn’t involve an eyeball in your local wound explorations!

General

Personal Decisions are the Leading Cause of Death

September 13, 2010 The Trauma Pro Leave a comment

A relatively obscure research paper published in late 2008 by Ralph Keeney at Duke University makes this startling claim: over half of the people who died in this country in the year 2000 did so because of their own personal decisions! If you look at current mortality statistics, the top four causes of death from year to year are heart disease, cancer, stroke and injury. We naturally look at this and think that these people had a heart attack or discovered a cancer or crashed their car. What these statistics fail to show is how the people really ended up with these conditions.

Keeney’s paper looked beyond what was written on the death certificate and looked at how frequently personal choices caused these conditions. For example, smoking leads to heart disease, cancer, stroke, and high blood pressure, to name a few. Being overweight leads to heart disease, diabetes, high blood pressure, and many others. Inappropriate use of alcohol can lead to cancer, liver disease and a tendency to get into accidents.

The top causes of death were analyzed, looking at the percentage that could be caused by personal decisions such as smoking, diet, exercise, and use of alcohol or other drugs. A personal decision was defined as a situation where the individual could make a choice between two or more readily available alternatives (for example, smoking and not smoking) and that they had control over this choice. These choices are not necessarily easy to make because habits, social pressure, or genetic predisposition can make some alternatives hard to select.

Keeney found that about 55% of deaths in 2000 were caused by personal decisions. This compares to about 5% in the year 1900. This is due to the fact that the majority of the causes of death in 1900 were due to infectious diseases, and there were no antibiotics at the time to treat them.

What this paper shows us is that the need for high quality prevention activities is even greater that we thought, and that we may not be focusing on the right areas.Trauma centers habitually direct their prevention programs toward car seats, diving injuries, red light running, falls prevention and others. What we really need to focus on is personal choice, and teaching people how to make the right decisions. For trauma prevention, alcohol-related programs will probably give the greatest result since it is involved in so many of the top causes of death, even causes not related to trauma.

Trauma centers need to scrutinize their own prevention programs, and look critically at ways they can teach wise choices. It may be necessary to chage the focus of existing programs, or move to new programs that find ways to influence personal decision making. That way, trauma centers can have a hand not only in preventing certain types of injuries, but in directly decreasing the overall death rate as well.

Reference: Keeney RL. Operations Research 56:6, 1335-1347, 2008.

General

Syncope Workup in Trauma Patients

September 7, 2010 The Trauma Pro Leave a comment

Syncope accounts for 1-2% of all ED visits, and is a factor in some patients with blunt trauma, especially the elderly. If syncope is suspected, a “syncope workup” is frequently ordered. Just what this consists of is poorly defined. Even less understood is how useful the syncope workup really is.

Researchers at Yale retrospectively looked at their experience doing syncope workups in trauma patients. They were interested in seeing what was typically ordered, if it was clinically useful, and if it impacted length of stay.

A total of 14% of trauma patients had syncope as a possible contributor to their injury. The investigators found that the following tests were typically ordered in these patients:

Carotid ultrasound (96%)
2D Echo (96%)
Cardiac enzymes (81%)
Cardiology consult (23%)
Neurology consult (11%)
EEG (7%)
MRI (6%)

Most of this testing was normal. About 3% of cardiac enzymes were abnormal, as were 5% of carotid imaging and 4% of echocardiograms.

Important! Of the patients who underwent an intervention after workup, 69% could have been identified based on history, physical exam, or EKG and did not depend on any of the other diagnostic tests.

Conclusion: Syncope workup is not needed routinely in trauma patients with syncope as a contributing factor. Need for intervention can usually be determined by history, exam and EKG performed in the ED. In this study, $216,000 in excess costs would have been saved!

Reference: Routine / protocol evaluation of trauma patients with suspected syncope is unnecessary. Davis, et al, Yale University. Presented at the 23rd Annual Scientific Assembly of the Eastern Association for the Surgery of Trauma, January 2010.

General

EMS: Which Field Airways Work The Best?

September 3, 2010 The Trauma Pro Leave a comment

Oral endotracheal intubation is the gold standard when a field airway is needed. However, they are not always possible due to protocol, training, patient anatomy or specific injuries. To allow airway support in these situations, a number of techniques and devices have been developed. The problem is, do we really know which one(s) are best?

To try to answer this question, a huge meta-analysis of all the English literature with information on success rates for these techniques was carried out. Over 2000 papers were identified, and they were narrowed down to 35 studies involving over 10,000 patients.

The success rates that they identified were as follows:

King LT airway – 96.5%
Esophageal Obturator / Esophageal Gastric Tube Airway – 92.6%
Surgical cricothyroidotomy – 90.5%
Laryngeal mask airway (LMA) 87.4%
Combitube – 85.4%
Pharyngeotrachael laryngeal airway (PTLA) – 82.1%
Needle cricothyroidotomy – 65.8%

The Bottom Line: The King airway has the highest success rate of the alternative airway devices, although there was less data available and the effectiveness of ventilation has not been worked out yet. The best percutaneous rescue airway was the surgical crich.

Reference: A Meta-Analysis of Prehospital Airway Control Techniques Part II: Alternative Airway Devices and Cricothyrotomy Success Rates. Prehospital Emergency Care 14(4):515-530, Oct-Dec 2010.

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