Management of Ammonia Exposure

After an ammonia leak last night in Rosemount MN, one person died at the scene and several people were treated at our trauma center. Ammonia exposure is not very common, but can cause serious injury or death. This blog will review the facts about ammonia exposure and provide basic management tips for EMS and hospital personnel.

Nearly everybody who has worked with household cleaning products is familiar with the odor of ammonia. The gas is colorless with a potent, irritating smell. Ammonia gas is added to water to make cleaning solutions. Farmers use anhydrous ammonia to make fertilizer, which is a very pure form that is drawn to moisture. Ammonia is usually transported under pressure in steel tanker trucks in the form of a clear liquid.

From the medical standpoint, ammonia causes problems because it combines with water to form ammonium hydroxide, a strong alkali (base). When humans are exposed, an alkaline solution forms on any moist areas such as skin, eyes and mucus membranes. Inhaling the gas causes deeper exposure and burns in the respiratory tract. Higher concentrations of gas cause greater injury, with eye damage occurring very commonly that can lead to blindness.

Prehospital management:

• Protect yourself! A HAZMAT Hot Zone should be established with all personnel entering the zone properly protected with SCBA breathing apparatus and chemical protective suits.
• If victims can walk, lead them out of the Hot Zone. If not, drag them.
• Patients with exposure to gas only do not pose a risk to EMS personnel. Decontamination is not necessary, and they can be moved to the Support Zone.
• Pay attention to ABC as you would with any trauma patient.
• All other patients require decontamination in the Decontamination Zone as follows:
• 1. Flush exposed skin and hair for at least 5 minutes. Use warm water if possible to avoid hypothermia. Wash with soap and water if possible.
• 2. Irrigate eyes for at least 15 minutes. Remove contact lenses if possible.
• 3. Double-bag contaminated clothing and personal belongings.
• 4. For ingestions, do not induce vomiting, attempt to neutralize, or give activated charcoal. Conscious victims should be encouraged to swallow 4-8 oz of water or milk. Prepare the ambulance for possible toxic emesis prior to transport.

Transport patients to the nearest Burn Center or burn-capable hospital.

The receiving Emergency Department should prepare a separate area to receive any patients with residual contamination for additional decontam. Decontamination times and methods are similar to prehospital. Patients exposed only to ammonia gas do not need a separate area.

For additional information, click here to download a detailed document from the Agency for Toxic Substances & Disease Registry, a part of DHHS.

How to Rapidly Reverse Coumadin in Head Injured Patients

A growing number of adults, usually elderly, are taking Coumadin (warfarin) to manage chronic medical conditions or deep venous thrombosis. While warfarin is a very useful drug for these problems, it is notoriously difficult to maintain tight control of INR. If an individual on warfarin is involved in a fall or vehicular crash, bleeding complications can become life-threatening. A recent Journal of Trauma article shows that mortality more than doubles in elderly patient who are admitted awake after just falling from standing.

The key is to rapidly reverse an elevated INR. Vitamin K can be used to increase biological activity of several clotting factors, but this occurs over several hours. Plasma is also used, but there are several considerations. Many hospitals have only frozen plasma, and there may be a delay of 30 to 45 minutes to thaw it. Multiple units may need to be transfused in order to normalize higher INRs, which may cause volume overload in elderly patients with cardiovascular disease.

More recently, activated Factor VII (NovoSeven) has been used to aid rapid reversal of the INR. NovoSeven is FDA approved for only the following uses:

• Bleeding or surgery in hemophiliacs
• Bleeding or surgery in congenital Factor VII deficiency

Use of NovoSeven for rapid reversal of warfarin is an off-label use, and physicians must weigh the risks and benefits prior to use. It is also very costly, about $7000 per vial.

To download a printable copy of our protocol, click here.

PROTOCOL – PATIENTS ON WARFARIN WITH HEAD INJURY AND ABNORMAL CT SCAN

Check INR. Goal INR is 1.2-1.4

If > 1.4

• Give Vitamin K 10 mg IV
• Transfuse thawed plasma 15ml/kg (4-6 units)
• Consider NovoSeven
  Weight <>= 100kg – give 2mg IV

Repeat INR at 2hrs, 4hrs, 12hrs and 24 hrs after NovoSeven administration.

If INR increases to > 1.4, repeat plasma transfusion as needed.

Reference: J Trauma. 2009 Jun;66(6):1518-22; discussion 1523-4.

NOTE: This guideline is based on protocols in use at the Regions Hospital Level I Adult and Pediatric Trauma Centers. As with any potent drugs or procedures, undesired side-effects may occur. The individual physician prescribing these medications or procedures is solely responsible for the safety of his or her individual patient.

Pulmonary Embolism and DVT in Trauma

We have long assumed that pulmonary emboli start as clots in the deep veins of the legs (or pelvis), then break off and float into the branches of the pulmonary artery in the lungs. A huge industry has developed around how best to deal with or prevent this problem, including mechanical devices (sequential compression devices), chemical prophylaxis (heparin products), and physical devices (IVC filters).

The really interesting thing is that less than half of patients who are diagnosed with a pulmonary embolism have identifiable clots in their leg veins. In one study, 26 of 200 patients developed DVT and 4 had a PE. However, none of the DVT patients developed an embolism, and none of the embolism patients had a DVT! How can this kind of disparity be explained?

Researchers at the Massachusetts General Hospital retrospectively looked at the correlation between DVT and PE in trauma patients over a 3 year period. DVT was screened for on a weekly basis by duplex venous ultrsonagraphy. PE was diagnoses exclusively using CT scan of the chest, but also included the pelvic and leg veins to look for a source. A total of 247 patients underwent the CT study for PE and were included in the study.

Forty six patients had PE (39% central, 61% peripheral pulmonary arterial branches) and 18 had DVT (16 seen on the PE CT and 2 found by duplex). Of the 46 patients with PE, only 15% had DVT. All patient groups were similar with respect to injuries, injury severity, sex, anticoagulation and lengths of stay. Interestingly, 71% of PE patients with DVT had a central PE, but only 33% of patients without DVT had a central PE.

The authors propose 4 possible explanations for their findings:

1. The diagnostics tools for detecting DVT are not very good. FALSE: CT evaluation is probably the “gold standard”, since venography has long since been abandoned
2. Many clots originate in the upper extremities. FALSE: most centers do not detect many DVTs in the arms
3. Leg clots do not break off to throw a PE, they dislodge cleanly and completely. FALSE: cadaver studies have not show this to be true
4. Some clots may form on their own in the pulmonary artery due to endothelial inflammation or other unknown mechanisms. POSSIBLE

An invited critique scrutinizes the study’s use of diagnostics and the lack of hard evidence of clot formation in the lungs.

The bottom line: this is a very intriguing study that questions our assumptions about deep venous thrombosis and pulmonary embolism. More work will be done on this question, and I think the result will be a radical change in our use of anticoagulation and IVC filters over the next 3-5 years.

Velmahos, Spaniolas, Tabbara et al. Arch Surg. 2009; 144(10):928-932.

Personal Decisions are the Leading Cause of Death

A relatively obscure research paper published last December 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.

Do Trauma Patients Need A Rectal Exam?

It has long been standard operating procedure to perform a digital rectal exam in all major trauma patients. The belief has always been that valuable information about blood in the GI tract, the status of the urethra, and the neuro exam (rectal tone) could be gleaned from the exam.

Unfortunately, the exam also serves to antagonize or even further traumatize some patients, especially those who may be intoxicated to some degree. On a number of occasions I have seen calm patients become so agitated by the rectal that they required intubation for control.

So is it really necessary? A study in 2001 conducted over a 6 month period (1) showed that the rectal exam influenced management in only 1.2% of cases. The authors felt that there was some utility in 3 special cases:

• Spinal cord injury – looking for sacral sparing
• Pelvic fracture – looking for bone shards protruding into the rectum
• Penetrating abdominal trauma – looking for gross blood

A more recent 2005 study (2) was also critical of the rectal exam and found that using “other clinical indicators” (physical exam and other diagnostic study information) was at least equivalent, changing management only 4% of the time. They concurred with the first two indications above as well.

The Bottom Line: For most major trauma patients, the rectal exam is not worth the patient aggravation it causes. I still recommend it for the 3 special cases listed above, however, as there are no equivalent exams for these potentially serious patient problems.

References:
1. Porter, Urcic. Am Surg. 2001 May;67(5):438-41.
2. Esposito et al. J Trauma. 2005 Dec;59(6):1314-9.

What Percent Pneumothorax Is It?

Frequently, radiologists and trauma professionals are coerced into describing the size of a pneumothorax seen on chest xray in percentage terms. They may something like “the patient has a 30% pneumothorax.”

The truth is that one cannot estimate a 3D volume based on a 2D study like a conventional chest xray. Everyone has seen the patient who has no or a minimal pneumothorax on a supine chest xray, only to discover one of significant size with CT scan.

Very few centers have the software that can determine the percentage of chest volume taken up with air. There are only two percentages that can be determined by viewing a regular chest xray: 0% and 100%. Obviously, 0% means no visible pneumothorax, and 100% means complete collapse. Even 100% doesn’t really look like 100% because the completely collapsed lung takes up some space. See the xray at the top for a 100% pneumothorax.

If you line up 10 trauma professionals and show them a chest xray with a pneumothorax, you will get 10 different estimates of their size. And there aren’t any guidelines as to what size demands chest tube insertion and what size can be watched.

The solution is to be as quantitative as possible. Describe the pneumothorax in terms of the maximum distance the edge of the lung is from the inside of the chest wall, and which intercostal space the pneumothorax extends to. So instead of saying “the patient has a 25% pneumo,” say “the pneumothorax is 1 cm wide and extends from the apex to the fifth intercostal space on an upright film.”

Use of Abdominal CT in Stab Wounds to the Anterior Abdomen

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!

Trauma Flow Sheets vs the Electronic Medical Record

There is a big push nationwide to move toward the use of electronic medical record (EMR)systems in hospitals. There are a number of benefits from using such systems, including but not limited to:

• Comprehensive and permanent data collection
• Easily accessed system-wide
• Reduction in human errors
• Increased throughput once the initial learning curve has been completed
• Multifaceted reporting capabilities

Many hospital or hospital system IT departments are insistent in moving all charting to the EMR, including the trauma flow sheet. For some, it is a revenue enhancement tool. For others, it is a result of the urge to make everything paperless.

As a trauma center reviewer, I have had the privilege of visiting many hospitals and inspecting their trauma flow sheet charting tools. The bottom line is that I have never seen an electronic medical record system that can replace a handwritten trauma flow sheet.

A trauma team activation is a complex, fast-paced, finely orchestrated performance that does not lend itself well to being recorded electronically. There are two major problems:

• Accurate and timely data entry
• Intelligible reports

There is so much information being transferred nearly simultaneously (vital signs, physical findings, procedures, fluid volumes given, laboratory and radiology orders, narratives) that it is not possible to record it completely and accurately using any current computer data entry interface or medical record system. Frequently, it ends up being recorded by hand on another piece of paper and is then entered later into the EMR.

The reporting features of virtually all EMRs allow for a nice event listing sorted by time. It is rarely graphical in nature, and typically spans multiple pages of text output. Charts that I have reviewed have “reports” ranging from 8 to 20 pages. It is virtually impossible for a human being to read through this type of output and reconstruct the flow of a trauma resuscitation. In many PI review cases, the trauma program manager is reduced to transcribing the individual data items from the EMR back onto a paper trauma flow sheet in order to conceptualize the resuscitation.

IT personnel may claim that the problem is an “end user failure.” I defy any of them to come to a trauma resuscitation and rapidly and accurately transcribe all of the information presented, or try to review a PI case based on a printed EMR report.

The real bottom line: trauma flow sheets (and other similar code sheets) can not and should not be reduced to electronic data entry. It is not only frustrating, but will hamper the trauma PI process to the point of jeopardizing a trauma center’s verification status!

A Quick and Dirty TBI Screen

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. To download a copy of this test instrument, click here. 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.

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.

Evaluation After Head Injury in Adolescents

Traumatic brain injury (TBI) is the most common cause of death in children. Even mild concussions can cause some degree of functional impairment. Many clinicians believe that the degree of impairment correlates with the initial Glasgow Coma Scale score (GCS), although this has only been shown in adults. This has led many hospitals to perform cognitive screening selectively, usually on adolescents with lower GCS scores.

A recent study by Goold and Vane at the Cardinal Glennon Children’s Medical Center in St. Louis, and the University of Vermont College of Medicine in Burlington looked at the correlation between GCS and level of impairment, and ways to determine which groups of adolescents need more sophisticated cognitive testing to evaluate deficits.

A total of 609 young adults age 13-21 with brain injuries were identified, and a cognitive screening test was performed (Occupational Therapy Head Injury Mini Screen [OT HIMS]). There was no correlation between GCS and the components of the OT HIMS. Interestingly, the GCS did not predict which patients were discharged to rehab centers either.

The Bottom Line: Adolescents can develop significant cognitive deficits or behavior issues after any degree of head injury. Because of this, it is not possible to selectively screen for cognitive deficits. All adolescents age 13-21 should undergo screening with an instrument like the OT HIMS after head injury.

At our Level I Pediatric Trauma Center, we consider a child to have a TBI if:

• the mechanism involves head impact and
• any of the following apply:
• known or suspected loss of consciousness
• cannot remember the event
• parents detect any change in behavior

All of these children undergo a TBI screen performed by Gillette Children’s Specialty Hospital physiatry, occupational and physical therapy services. If needed, they receive followup in the Gillette Minor Neurotrauma Clinic.

Reference: Goold D, Vane DW. Evaluation of Functionality After Head Injury in Adolescents. Journal of Trauma 2009;67:71-74.

Forensic Nursing

A recent article in USA Today has focused interested in a little-known area of nursing involving forensics. Click here to see the article.

Forensic Nursing combines nursing science with the investigation of injuries or deaths that involve accidents, abuse, violence or criminal activity. Sexual Assault Nurse Examiners (SANE nurses) are one of the most recognized types of forensic nurses, but they have special training in one type of injury. Forensic nursing typically involves a broader set of skills, encompassing some or all of the following:

• Interpersonal violence, including domestic violence, child and elder abuse/neglect, psychological abuse
• Forensic mental health
• Correctional nursing
• Legal nurse consulting
• Emergency/trauma services, including auto and pedestrian accidents, traumatic injuries, suicide attempts, work-related injuries, disasters
• Patient care facility issues, including accidents/injuries/neglect, inappropriate treatments & meds
• Public health and safety, including environmental hazards, alcohol and drug abuse, food and drug tampering, illegal abortion practices, epidemiology, and organ donation
• Death investigation, including homicides, suicides, suspicious or accidental deaths, and mass disasters

Forensic nurses find that their additional training improves their basic nursing skills, and allows them to derive greater career satisfaction from helping patient in another rather unique way.

Approximately 37 training programs exist, ranging from certificate programs that require a specific number of hours of training, to degree programs (typically Masters level programs). Many of the certificate programs are available as online training. Click here for information on these programs. http://www.iafn.org/displaycommon.cfm?an=1&subarticlenbr=50

Source: International Association of Forensic Nurses (http://www.iafn.org/)

Cervical Spine Clearance

Cervical spine clearance can be challenging in trauma patients. I will review simple algorithms for clearing the c-spine in the emergency department, and for clearing it in an inpatient.

Clearing the c-spine requires two things: evaluation of the bones and evaluation of the ligaments. There is some new literature that suggests that it may be possible to clear based on a high quality cervical CT scan only. However, there is not yet enought data to adopt this as a standard of care.

A copy of a clearance algorithm for use in the ED will be available shortly.
Click here to download a copy of our clearance algorithm for inpatients with normal mental status.

A complete evaluation of both bones and ligaments can be performed in a few patients by a clinical exam alone. However, this requires several things:

1. Awake and alert
2. Not intoxicated
3. No "distracting injuries." These are painful injuries that may preclude the patient being aware of discomfort in their neck.

If these conditions are met, then a careful exam of the neck can allow spine clearance. The exam consists of:

• Palpation of the cervical spine in neutral position
• Gentle flexion and extension to the limits of comfort
• Left and right rotation to the limits of comfort
• Gentle compression by pressing on top of the head

If at any point the patient experiences pain or tenderness in the posterior midline, then the clearance process is terminated and the collar replaced. Pain or tenderness in the paraspinous muscles is common and is not a contraindication to clearance. If all maneuvers are successfully completed, then the collar can be removed and clearance documented in the medical record.

For patients who are not eligible for clinical clearance, the vertebrae must be evaluated radiographically. Although standard cervical views can be obtained with conventional radiography, helical CT has become the standard. Once radiographic clearance is complete, clinical clearance can be performed using the guidelines listed above.