All posts by TheTraumaPro

CT Contrast Administration Via Intraosseous Cathether

The standard of care in vascular access in trauma patients is the intravenous route. Unfortunately, not all patients have veins that can be quickly accessed by prehospital providers. Introduction of the intraosseous device (IO) has made vascular access in the field much more achievable. And it appears that most fluids and medications can be administered via this route. But what about iodinated contrast agents via IO for CT scanning?

Physicians at Henry Ford Hospital in Detroit published a case report on the use of this route for contrast administration. They treated a pedestrian struck by a car with a lack of IV access sites by IO insertion in the proximal humerus, which took about 30 seconds. They then intubated using rapid sequence induction, with drugs injected through the IO device. They performed full CT scanning using contrast injected through the site using a power injector. Images were excellent, and ultimately the patient received an internal jugular catheter using ultrasound. The IO line was then discontinued.

This paper suggests that the IO line can be used as access for injection of CT contrast if no IV sites are available. Although it is a single human case, a fair amount of studies have been done on animals (goats?). The animal studies show that power injection works adequately with excellent flow rates.

The authors prefer using an IO placement site in the proximal humerus. This does seem to cause a bit more pain, and takes a little practice see the video above). A small xylocaine flush can be administered to reduce injection discomfort in awake patients. Additionally, the arm cannot be raised over the head for the torso portion of the scan.

Bottom line: CT contrast can be injected into an intraosseous line (IO) with excellent imaging results. Insert the IO in a site that you are comfortable with. I do not recommend power injection at this time. Although the marrow cavity can support it, the connecting tubing may not. Have your radiologist hand-inject and time the scan accordingly.

Note: long term effects of iodinated contrast in the bone marrow are not known. For this reason, and because of smaller marrow cavities, this technique is not suitable for pediatric patients.

Related post: Air embolism from an intraosseous line

Reference: Intraosseous injection of iodinated computed tomography contrast agent in an adult blunt trauma patient. Annals Emerg Med 57(4):382-386, 2011.

Helicopter Transport of Trauma Patients Saves Lives

Helicopter EMS (HEMS) transport of trauma patients is used primarily to decrease the amount of time between injury and arrival at the trauma center. Unfortunately, efficacy studies have provided conflicting answers as to whether this is actually true. Last year, the CDC completed a large sample study of this issue using the National Trauma Data Bank (NTDB) in an attempt to determine if HEMS flights are effective.

Using almost 150,000 entries in the NTDB for 2007, they were able to isolate over 56,000 adult records with complete data points. They looked for mortality patterns based on age, injury severity, and revised trauma score, comparing patients who were transported by air vs ground.

They found the following:

  • Odds of dying in-hospital were 39% lower overall when transported by helicopter
  • This survival advantaged disappeared for patients age 55 and older, possibly because of decreased reserve, comorbidities, more complications, or medications that interfere with successful resuscitation
  • Regardless of type of transport, males always fared worse than females

Bottom line: This is a large and intriguing study. About 85% of the US population has access to a Level I or II trauma center within an hour. However, a third of those can only get there in that period of time if transported by air. This mode of transport has a significantly lower mortality rate. However, there are cost and safety considerations as well. The key now is to figure out which patients will have the best outcomes after air transport. This will require more work, looking at more than just mortality (e.g. disability, complications). And what’s the deal with men having poorer outcomes???

Reference: Reduced mortality in injured adults transported by helicopter emergency medical services. Prehospital Emerg Care 15(3):295-302, 2011.

Resident Work Hour Restrictions And Neurotrauma Complications

In the US, resident work hour restrictions went into effect in 2003, limiting the total number of hours worked per week and the number of consecutive hours without a break. The idea was that fatigue caused errors, which translates into patient complications or worse. Has this panned out? A number of previous publications have found no change; only a few have shown some benefit.

Researchers at Massachusetts General Hospital decided to apply the acid test to this theory. They selected a group of patients who were critically ill and challenging to care for, taken care of by a group of residents who had long work hours and were involved in long operative cases. The AHRQ National Inpatient Sampling Database was studied, comparing the outcomes of neurotrauma patients before and after work hours were initiated and in teaching and non-teaching centers.

A huge number of records were analyzed (40,000 before work hours restrictions, 67,000 after). The findings were intriguing:

  • The overall complication rate was the same before and after restrictions (1.2%)
  • The complication rate was 25% higher in teaching hospitals after restrictions took effect. It appears that this also correlated with higher hospital charges after restrictions.
  • Logistic regression was used to figure out whether this difference was from duty hours or just from the involvement of residents in care. Only duty hours were significant in this analysis.
  • If injury severity was included in the analysis, there were no differences in complications at all
  • There were no differences in mortality rates between any of the groups

Bottom line: Yes, fatigue is bad (see my previous posts below). But here is another (correlation) study that doesn’t bear out the original reasons to restrict resident work hours. In actuality, complications and charges increased after the restrictions went into effect. It is possible that the checks and balances in the system were effective in protecting patients from adverse outcomes. Could the changes in this study be due to staffing changes to meet the restrictions, which results in chronic understaffing which undercuts those checks and balances? Studies of this type can’t tell us that. And unfortunately, restrictions in the US are not going to go away, they’ll probably get worse.

Related posts:

Reference: Higher Complications and No Improvement in Mortality in the ACGME Resident Duty-Hour Restriction Era: An Analysis of More Than 107?000 Neurosurgical Trauma Patients in the Nationwide Inpatient Sample Database. Neurosurgery 70(6):1369-1382, 2012.

Technique: How To Close A Full Thickness Stab (Abdomen) Laparoscopically

The algorithm for evaluating a stab to the anterior abdomen includes a number of different techniques for evaluation. In some cases where the chance of entry into the abdomen is thought to be low probability, endoscopic exploration can be used. What if a full thickness stab is detected, but the surgeon is able confirm that no abdominal injuries are present? Should the stab defect be closed?

There is no good data that tells us the incidence of ventral hernia from stab wounds. We do know that 10mm endoscopic port sites and larger can be the source of a ventral hernia and possible bowel obstruction after laparoscopic surgery, so it stands to reason (but be careful) that the same thing could happen with larger stabs. So why not close them?

A number of commercial devices have been developed for port site closure during endoscopic surgery (Carter Thomason Closure System, Cooper Surgical; Endo Close, Covidien). A group in Tokyo published a description of the technique using the former device to close the fascial defect of a self-inflicted stab wound.

Bottom line: This is an interesting use for a device used for closing more controlled stab wounds (surgical port sites) in less controlled ones. It seems fair to extrapolate our current experience from laparoscopic surgery to trauma in this case. I would be very interested to hear from anyone who is currently using this technique.

Reference: A quick and easy closure technique for abdominal stab wound after diagnostic laparoscopy. J Trauma 72(5):1448-1449, 2012.

Angioembolization For Splenic Injury

Initial nonoperative management of splenic injury is standard in hemodynamically stable patients. Over the past decade, the success rates have climbed by adding angioembolization to the algorithm, according to several published series. However, the objective benefit and specific indications have not been worked out.

A paper published this month by the University of Florida, Jacksonville used the NTRACS registry to try to clarify these issues. They identified 1039 patients undergoing nonoperative management (NOM) over a nearly 10 year period. Patients who died shortly after arrival, those who went directly to OR for hemodynamic reasons, and children were excluded, leaving 539 patients. Only about 1/6 of the patients underwent embolization. 

The overall failure rate was about 4%, a little higher in the non-angio patients, a little lower with angio. Incidentally, the angio group had significantly higher injury severity (26 vs 20). Analysis of the lower grade spleen injury group showed no improvement in success rate by adding angio. However, the high grade groups (grades IV-V) did benefit by adding this procedure. Similarly, success improved when performing angio in patients with contrast blush or evidence of slow, ongoing bleeding. If NOM did fail, it usually occurred on day 2.

Bottom line: Although we’ve been adding angio to non-operative management of spleen and liver injury for a decade, here’s the first paper that has been able to define the real indications for doing it. First, all unstable patients go to the OR (don’t even consider nonop management). In the remaining patients, if the CT shows a grade IV or V injury, or a contrast blush, angio is recommended. If neither of these is noted, but the hemoglobin continues to decline “too quickly” (surgeon judgement), then a trip to angio is also warranted. Applying these principles can increase your success rate to about 96%.

Related post:

Reference: Selective angiographic embolization of blunt splenic traumatic injuries in adults decreases failure rate of nonoperative management. J Trauma 72(5):1127-1134, 2012.