Autotransfusing blood that has been shed from the chest tube is an easy way to resuscitate trauma patients with significant hemorrhage from the chest. Plus, it’s usually not contaminated from bowel injury and it doesn’t need any fancy equipment to prepare it for infusion.
It looks like fresh whole blood in the collection system. But is it? A prospective study of 22 patients was carried out to answer this question. A blood sample from the collection system of trauma patients with more than 50 cc of blood loss in 4 hours was analyzed for hematology, electrolyte and coagulation profiles.
The authors found that:
- The hemoglobin and hematocrit from the chest tube were lower than venous blood (Hgb by about 2 grams, Hct by 7.5%)
- Platelet count was very low in chest tube blood
- Potassium was higher (4.9 mmol/L), but not dangerously so
- INR, PTT, TT, Factor V and fibrinogen were unmeasurable
Bottom line: Although shed blood from the chest looks like whole blood, it’s missing key coagulation factors and will not clot. Reinfusing it will boost oxygen carrying capacity, but it won’t help with clotting. You may use it as part of your massive transfusion protocol, but don’t forget to give plasma and platelets according to protocol. This also explains why you don’t need to add an anticoagulant to the autotransfusion unit prior to collecting or giving the shed blood!
Related post: Chest tubes and autotransfusion
Reference: Autotransfusion of hemothorax blood in trauma patients: is it the same as fresh whole blood? Am J Surg 202(6):817-822, 2011.
Trauma professionals worry about radiation exposure in our patients. A lot. There are a growing number of papers dealing with this topic in the journals every month. The risk of dying from cancer due to CT scanning is negligible compared to the risk from acute injuries in severely injured patients. However, it gets a bit fuzzier when you are looking at risk vs benefit in patients with less severe injuries. Is it possible to quantify this risk to help guide our use of CT scanning in trauma?
A nice paper from the Mayo clinic looked at their scan practices in 642 adult patients (age > 14) over a one year period. They developed dose estimates using a detailed algorithm, and combined them with data from the Biological Effects of Ionizing Radiation VII data. The risk level for injury was estimated using their trauma team activation criteria. High risk patients met their highest level activation criteria, and intermediate risk patients met their intermediate level activation criteria.
Key points in this article were:
- Average radiation dose was fairly consistent across all age groups (~25mSv)
- High ISS patients had a significantly higher dose
- Cumulative risk of cancer death from CT radiation averaged 0.1%
- This risk decreased with age. It was highest in young patients (< 20 yrs) at 0.2%, and decreased to 0.05% in the elderly (> 60 yrs)
Bottom line: Appropriate CT scan use in trauma evaluation is challenging. It’s use is widespread, and although it changes management it has not decreased trauma mortality. This paper shows that the risk of death from trauma in the elderly outweighs the risk of death from CT scan radiation. However, this gap narrows in younger patients with less serious injuries because of their very low mortality rates. Therefore, we need to focus our efforts to reduce radiation exposure on our young patients with minor injuries.
- Comparison of trauma mortality and estimated cancer mortality from computed tomography during initial evaluation of intermediate-risk trauma patients. J Trauma 70(6):1362-1365, 2011.
- Health risks from low levels of ionizing Radiation: BEIR VII, Phase 2. Washington DC: The National Academies Press, 2006.
I’ve previously written about management of extraperitoneal bladder injuries. One of the tenets is that every injury needs to have a routine followup cystogram to ensure healing and allow removal of any bladder catheter. I routinely like to question dogma, so I asked myself, is this really necessary? A retrospective registry review from the Ryder trauma center in Miami helped to answer this question.
Over 20,000 records were screened for bladder injury and 87 were found in living patients. Fifty were intraperitoneal injuries, and half of them were caused by pelvic fractures (interesting). All were operated on, and 47 were classified as simple (dome disruption or through and through penetrating) and 3 were “complex” (involving trigone). All trackable patients (42 of the 50) had followup cystograms 9-16 days later. All of the simple injuries had a normal followup exam, but a leak was detected on one of the complex injuries.
There were 42 patients with extraperitoneal bladder injuries. All were due to blunt trauma, and 92% were associated with pelvic fractures. Most were found with CT cystogram. Two patients had operative repair, probably due to the need to fix the pubic bones with hardware. 37 of the 42 were available for followup, and 22% of repeat cystograms were positive (average study done on day 9). In the studies that showed a leak, repeat cystograms were done, and they took an average of 47 days to fully heal.
Bottom line: Patients with extraperitoneal or complex intraperitoneal bladder injuries (trigone) really do need a followup cystogram before removing the bladder catheter. Those who underwent a simple repair of their intraperitoneal injury do not.
Reference: Cystogram follow-up in the management of traumatic bladder disruption. J Trauma 60(1):23-28, 2006.
Spine Clearance For Nurses
This 11 minute video provides information on the cervical spine clearance process in awake patients, reviews activity restrictions associated with the use of cervical collars, and discusses information about specific type of collars. It is designed for ED nurses and non-ED nurses who may encounter cervical spine collars.
Pregnant women get seriously injured, too. And pregnancy is an independent risk factor for deep venous thrombosis. We reflexively start at-risk patients on prophylactic agents for DVT, the most common being enoxaparin. But is it safe to give enoxaparin during pregnancy?
Studies have looked at drug levels in cord blood when the mother is receiving enoxaparin, and none has been found. No specific bleeding complications have been identified, either. So from the baby’s standpoint, administration is probably safe.
However, there are two other issues to consider. In a study looking at the use of enoxaparin for prophylaxis in women with a mechanical heart valve, 2 of 8 women (and their babies) died. Both suffered from clots that developed and blocked the valves. Most likely, the standard dose of enoxaparin was insufficient, so monitoring of anti-Factor Xa levels must be done.
The other problem lies in the multi-dose vial of Lovenox (Sanofi-Aventis). Each 100mg vial contains 45mg of benzyl alcohol, which has been associated with a fatal “gasping syndrome” in premature infants. The individual dose syringes do not have this preservative.
Bottom line: It is probably safe to give enoxaparin to pregnant women after trauma. However, it is unclear if the dose needs to be increased to achieve adequate prophylaxis. Only consider using this medication after consultation with the patient’s obstetrician, and use only the individual dose syringes. Otherwise fall back to standard subcutaneous non-fractionated heparin (even though it is a Category C drug by FDA; it is still considered the anticoagulant of choice during pregnancy).