Here’s the final post on my series covering serial hemoglobin testing in the management of solid organ injury.

We developed our first iteration of a solid organ injury practice guideline at Regions Hospital way back in 2002. It was borne out of the enormous degree of clinical variability I saw among my partners. We based it on what little was publicly available, including an EAST practice guideline.

Recognizing that the EAST guideline couldn’t dictate bedside care, we gathered together to meld it with our own clinical experience. We fashioned our first practice guideline later that year and tested it.  It included instructions for bed rest (only overnight), vital signs monitoring, and lab testing (on admission and once the next day).

That last bit about serial lab tests is important. We had seen anecdotal evidence in our patients that it wasn’t very helpful. For example, I had one patient in the ICU whose serial Hgb had just returned normal. However, a minute later, they experienced a hard hypotensive episode, and I took him immediately to the OR and took out a ruptured and bleeding spleen.

I’ve written several posts on how quickly Hgb changes after hemorrhage. Unfortunately, this lab test just lags too long to be a reliable indicator of anything. A very recent study has been published by Texas Health Presbyterian in Dallas. The retrospectively reviewed patients with liver or spleen injury over five years. They examined how often serial hemoglobin determinations influenced management during the study period. Possible interventions were none, operation, angioembolization, or blood transfusion.

Here are the factoids:

• There were 143 patients enrolled, and half had no interventions, a third had interventions within 4 hours, and the remainder (16%) had an intervention after 4 hours
• In the early intervention group, one-third underwent laparotomy, 42% angiography, and 9% had both; 17% received transfusions based on clinical parameters alone and not lab results
• Of the 16% that did have a later intervention (23 patients), 12 received a blood transfusion only based on a Hemoglobin value, and all but one had no further interventions. That patient had a laparotomy based on the lab test.
• All other patients in the late intervention group went to the OR or angioembolization based on hemodynamics or a change in physical exam.
• The number of blood draws was phenomenal, with an average of 19 in the early intervention group, 17 in the delayed intervention group, and 7 in the no-intervention group

The authors concluded that serial hemoglobin measurements were not well supported by the literature and that the decision to intervene was nearly always driven by hemodynamics or physical exam.

Bottom line: Although this study is small, the results are very clear. As we were taught in our surgical training, hemodynamics and physical exam are vital in managing solid organ injury. Unfortunately, hemoglobin is a lagging indicator, and the repeated discomfort and unnecessary cost overshadow its clinical value. This is most significant when treating pediatric patients.

Try to recall the last time you and your trauma colleagues had a patient whose need for intervention was based on a lab draw. Now take your practice guideline back to the drawing board and eliminate the serial exams!

Reference: Role of Serial Phlebotomy in the Management of Blunt
Solid Organ Injury in Adults. J Trauma Nurs 30(3), 135–141, 2023.

In my last post, I waxed theoretical. I discussed the potential reasons for measuring serial hemoglobin or hematocrit levels and the limitations imposed by the rate of change in these values. I conjectured about how often they should be drawn.

And now, how about something more practical? How about some actual research? One of the more common situations for ordering serial hemoglobin draws is in the management of solid organ injury. The vast majority of the practice guidelines I’ve seen call for repeating blood draws about every six hours. The trauma group at the University of Florida in Jacksonville decided to review their experience in patients with liver and spleen injuries. They hypothesized that hemodynamic changes would be more likely to prompt changes in management than lab value changes.

They conducted a retrospective review of their experience with these patients over one year. Patients with higher-grade solid organ injury (Grades III, IV, V), either isolated or in combination with other trauma, were included. Patients on anticoagulants or antiplatelet agents, as well as those who were hemodynamically unstable and were immediately operated on, were excluded.

Here are the factoids:

• A total of 138 patients were included, and were separated into a group who required an urgent or unplanned intervention (35), and a group who did not (103)
• The intervention group had a higher ISS (27 vs 22), and their solid organ injury was about 1.5 grades higher
• Initial Hgb levels were the same for the two groups (13 for the intervention group vs 12)
• The number of blood draws was the same for the two groups (10 vs 9), as was the mean decrease in Hgb (3.7 vs 3.5 gm/dl)
• Only the grade of spleen laceration predicted the need for an urgent procedure, not the decrease in Hgb

Bottom line: This is an elegant little study that examined the utility of serial hemoglobin draws for determining the need for more aggressive interventions in patients with solid organ injury. First, recognize that this is a single-institution, retrospective study. This just makes it a bit harder to get good results. But the authors conducted a power analysis to ensure enough patients were enrolled to detect a 20% difference in outcomes (intervention vs no intervention). 

Basically, they found that everyone’s Hgb started out about the same and drifted downward by roughly the same amount. But the group that required intervention was defined by the severity of the solid organ injury, not by any change in Hgb.

I’ve been preaching this concept for more than 20 years. I remember hovering over a patient with a high-grade spleen injury in whom I had just sent off the requisite q6-hour Hgb as he became hemodynamically unstable. Once I finished the laparotomy, I had a chance to pull up the result: 11 g/dL! 

Humans bleed whole blood. It takes a finite amount of time to pull fluid from the interstitium to “refill the tank” and dilute the Hgb value. For this reason, hemodynamics will always trump hemoglobin levels for making decisions regarding further intervention. So why get them?

Have a look at the Regions Hospital solid organ injury protocol using the link below. It has not included serial hemoglobin levels for 18 years, since it was written. Take care to look at the little NO box on the left side of the page.

I’d love to hear from anyone who has also abandoned this little remnant of the past. Unfortunately, I think you are in the minority!

Reference: Serial hemoglobin monitoring in adult patients with blunt solid organ injury: less is more. J Trauma Acute Care Open 5:3000446, 2020.

The serial hemoglobin (Hgb) determination. We’ve all done them. Not only trauma professionals, but also other in-hospital clinical services as well. But my considered opinion is that they are not of much use. They inflict pain. They wake patients up at inconvenient hours. And they are difficult to interpret. So why do them?

I’m reposting this mini-series on serial hemoglobin draws in light of a new paper that was published in the Journal of Trauma Nursing. It continues next week with Part 2, and then a summary of the new paper.

First, what’s the purpose? Are you looking for trends or for absolute values? In trauma, the most common reason to order is “to monitor for bleeding from that spleen laceration” or some other organ or fracture complex. But is there some absolute number that should trigger an alarm? If so, what is it? The short answer is, there is no such number. Patients start at a wide range of baseline values, so it’s impossible to know how much blood they’ve lost using an absolute value. And we don’t use a hemoglobin or hematocrit as a failure criterion for solid organ injury anymore, anyway.

What about trends, then? First, you have to understand the usual equilibration curve of Hgb/Hct after acute blood loss. It’s a hyperbolic curve that reaches equilibrium after about 3 days. So even if your patient bled significantly and stopped immediately, their Hgb will drop for the next 72 hours anyway. If you really want to confuse yourself, give a few liters of crystalloid on top of it all. The equilibration curve will become completely uninterpretable!

And how often should these labs be drawn? Every 6 hours (common)? Every 4 hours (still common)? Every 2 hours (extreme)? Draw them frequently enough, and you can guarantee eventual anemia.

Bottom line: Serial hemoglobin/hematocrit determinations are nearly worthless. They cost a lot of money, they disrupt needed rest, and no one really knows what they mean. For that reason, my center does not even include them in our solid organ injury protocol. If bleeding is ongoing and significant, we will first look at vital signs and a good old physical exam. But if you must, be sure to explicitly state what you will do differently at a certain value or trend line. If you can’t do this and stick to it, then you shouldn’t be ordering these tests in the first place!

In my next post, I’ll discuss a paper that objectively shows the (lack of) utility of this testing method.