Welcome to “Next Gen Shorts”, where we look to take a recent study
focused on military and prehospital medicine, and condense it into a quick
manageable read to ensure you get what’s most important for your practice.

Today’s paper is on the safety of physical exertion following whole blood

The Background:

The employment of whole blood (WB) in the prehospital environment demonstrates
improved patient outcomes and is supported by Committee on Tactical Combat Casualty Care and Joint Trauma System resuscitation guidelines, but logistical difficulties of acquisition and storage in remote environments often preclude regular supply.1,2  The use of a walking blood bank (WBB) to acquire and transfuse WB has therefore become a
focus of training and planning for far-forward combat operations and remote damage control resuscitation.  However, despite this focus, the expectation of continued physical performance of potential WB donors is still largely undefined.

Civilian literature demonstrates scattered but significant adverse events (AE) to include dizziness, weakness, nausea, vomiting, and syncope.  Only a few military-based papers support continued physical performance by WB donors, however this has been almost exclusively in Norwegian military forces, and largely amongst their special operations

To date, no published evidence exists supporting continued physical exertion in American
active duty service members following WB donation.

Precious elixir of hemorrhagic resuscitation.

The Paper:

Carius BM, Umar M, Aden JK, Schauer SG. An Analysis of Exertional Safety After Blood Donation in Active Duty Military Personnel-A Feasibility Study. Mil Med. 2020 Nov 2:usaa234. doi: 10.1093/milmed/usaa234. Epub ahead of print. PMID: 33135736.

The Question:

Is basic physical exertion safe in active duty service members soon after donating 1 unit of whole blood?

What the Researchers Did:

– A prospective trial of 25 active duty service members at Fort Sam Houston, Texas

– Volunteers completed a 1-mile treadmill run at their age-adjusted minimum APFT 2-mile passing score pace

– Volunteers completed 1 unit of WB donation 1 week after baseline testing, then repeated physical exertion testing

– The primary outcome of concern was occurrence of AE during exertion testing, including subjective AE (chest pain, shortness of breath, dizziness) and objective AE (tachycardia at rest, hypotension at rest, syncope)

– Resting and post-exertion vital sign measurements and perceived physical exertion
scores were documented with each phase of exertional testing

Demographic Results

– 19 males (76%), 6 females (24%)

– Age range 22-47 years old (average 33 years old)

– All volunteers completed post-donation exertion testing approximately 1 hour after completing WB donation


Research Question Results:

– There were NO documented AE throughout all phases of testing

– Comparison of resting vital sign measurements:

  • HR had a significant increase (68 vs. 73 bpm, p < 0.01)
  • SBP, DBP, RR had no significant change

– Comparison of post-exertion vital sign measurements:

  • HR had a significant increase (112 vs. 119 bpm, p < 0.01)
  • SBP, DBP, RR had no significant change

– There were no significant changes on comparison between genders



Basic physical exertion can be performed safely by active duty service members soon after 1 unit of WB donation.  Isolated changes to HR were statistically significant but not clinically significant.


Medic Bottom Line:
Prior Norwegian Special Forces-based studies demonstrate physical exertion is safe following WB donation.  This feasibility study in a general American active duty service member population further supports that physical exertion is safe following WB donation. Increased battlefield-focused studies are needed in this population, but for now, there is no good evidence to suggest that physical limitations are needed in otherwise healthy military populations following WB donation.


  1. Butler FK, Holcomb JB, Schreiber MA, et al. Fluid resuscitation for hemorrhagic shock in tactical combat casualty care: TCCC guidelines change 14-01 2 June 2014. JSOM. 2014;14(3):13-38.
  2. Cap AP, Gurney J, Spinella PC, et al. Damage control resuscitation. Joint Trauma System Clinical Practice Guideline. Available at: https://jts.amedd.army.mil/index.cfm/PI_CPGs/cpgs. Accessed October 30, 2020.
  3. Strandene G, Skogrand H, Spinella PC, Hervig T, Rein EB. Donor performance of combat readiness skills of special forces soldiers are maintained immediately after whole blood donation: a study to support the development of a prehospital fresh whole blood
    transfusion program. Transfusion. 2013;53(3):526-30.