Page 113 - JSOM Spring 2023

% pFVC and total number of rib fractures are both potentially value of % pFVC or other spirometry measures studied else-
useful measures that may capture different underlying factors where may lie in using them with a count of rib fractures, in
relating to increased risk. addition to other demographic variables such as age or pulmo-
nary comorbidities to best identify high- and low-risk patients
Our study was part of a new Early Aggressive Chest Interven- with rib fractures. Previous studies have proposed other scor-
tion (EACI = “EASY”) Rib Fracture Protocol, Brooke Army ing metrics to better risk stratify patients with rib fractures.

Medical Center’s new clinical practice guideline. The purpose These include the SCARF score and RibScore, which incorpo-
of this protocol was to improve the institution’s outcomes re- rate additional variables beyond the number of rib fractures.
garding patients with rib fractures and to decrease the risk of The RibScore also does not incorporate any physiologically
the associated long-term complications. Use of such protocols objective measures or incentive spirometry measurements. 23,24
has shown to reduce ICU LOS, hospital LOS, and pneumonia We propose that % pFVC may be a better predictive variable
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in patients with rib fractures. This study adds % pFVC as an and in the future should be added as a component of these ex-
additional physiologic tool to help identify which patients are isting scoring systems to improve their accuracy. Alternatively,
likely to need additional care in our and other protocols. a new scoring system could be designed given our findings
and could be corrected for variables in size for the individual
The use of a rib fracture protocol has recently been shown to patient. 23,24
reduce ICU length of stay, hospital length of stay, and pneu-
monia in patients with rib fractures and also a trend toward Though this protocol was tested and validated at a stateside
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reduced mortality. This study adds % pFVC as an additional Level I Trauma Center, these findings also hold relevance for
tool to help identify which patients are likely to need addi- military combat casualty care, theater hospitals, and austere
tional care in our and other protocols. As an adjunct, % pFVC or resource-limited settings, such as prolonged casualty care
can potentially risk-stratify patients (% pFVC > 50% being (PCC). First, bedside spirometry or using a respirometer is
low risk), which can be used to triage these patients to ICU or a straightforward procedure that respiratory therapists and
non-ICU level care. In our study, those who had a % pFVC > other ancillary staff could help perform even in remote set-
50% had zero ICU readmissions and were more likely to be tings. In fact, bedside or point-of-care spirometry is currently
discharged to their home. being used to better manage chronic obstructive pulmonary
disease (COPD) patients and determine suitability for lung
From a pulmonary function standpoint, Amital et al. (2009) transplant in extracorporeal membrane oxygenation (ECMO)
found that for up to two years after pulmonary contusion and patients at some hospitals. 25,26
rib fractures, multiple PFT parameters and exercise tolerance
are compromised, with a maximum rate of O consumption Second, measurement of FVC and calculation of % pFVC pro-
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(VO )max of 60% predicted. In patients with flail chest, 50– vide a tool for prioritizing patients for evacuation by using an
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60% develop permanent morbidity with persistent chest wall objective physiologic measure and not simply relying on age
pain or deformity as the most common long-term problems. and number of rib fractures. This will help for planning as a
As many as 40% of these patients still had not returned to casualty moves through the system from prolonged casualty
work one year after their injury. 15,16 care to critical care air transport to determine appropriateness
and priority for evacuation. This is of further importance as
While the predominant research seeking to risk stratify pa- large-scale combat operations (LSCO) and multi-domain op-
tients with rib fractures have focused on the total number of rib erations (MDO) will quickly overwhelm in theater hospitals
fractures, several previous studies have looked at pulmonary and medical assets (e.g., a 240-bed hospital center). In envi-
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function via spirometry in rib fracture patients. 16–19 Schuster et ronments where the US no longer has air superiority, PCC and
al. (2020) prospectively evaluated the spirometry measures of effective triage will be essential. In fact, a recent brigade-size
FVC, forced expiratory volume one second (FEV1), and nega- rotation at a Combat Training Center (CTC) simulating LSCO
tive inspiratory force (NIF). The authors found that increased found 47.3% of casualties dying from wounds, and the pri-
FVC and FEV1 were associated with discharge to home and mary reason was due to evacuation delay. 28
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that FEV1 on admission correlated with hospital LOS. In
their study, they found that a statistical relationship with these Lastly, as the military focus transitions from counterterror-
spirometry measures was more valuable than pain assessment ism to potential LSCO with near-peer competitors and pacing
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in predicting outcomes. Warner et al. (2018) similarly found threats such as Russia and China, Special Operations Forces
in their retrospective analysis that patients with an FVC less (SOF) seek to maintain a seat at the table. Recent directives
than 1L at any point during their hospital admission had an from SOF leadership highlight a vision that focuses on how
associated increased risk of pneumonia, unplanned ICU ad- SOF can align and integrate with conventional forces to help
mission, intubation need, and mortality. 19 meet these national strategic and security aims and needs. It
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highlights this practice as integrated deterrence. To do this,
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Khan et al. (2020) and Billings et al. (2021) developed and SOF medical assets will likely find themselves much more en-
then compared a change in their institutional clinical practice meshed with traditional and conventional medical assets. In
guidelines from the use of FVC to % pFVC for admission risk these settings, triage tools such as EACI could serve as a lingua
stratification in patients with rib fractures. They found that franca or bridge to help prioritize resources and evacuation.
the use of % pFVC to risk stratify resulted in fewer unplanned
ICU transfers, suggesting it is a better predictor of late pulmo- Our study had inherent limitations common to many prospec-
nary complications. 21,22 tive studies, such as the number of pulmonary complications
that occurred and the modest sample size. Obtaining FVC
This study adds to this body of research by expanding on suit- at admission proved to be logistically challenging due to un-
ability of % pFVC as a valid risk stratifying metric. The true availability of respiratory therapists being able to perform this

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