Using Hemoglobin View on SnapshotNIR In Clinical Practice

Monitoring hemoglobin trends can shed light on conditions that may be missed with other standalone assessment techniques. Combine clinical judgement and objective data for actionable ways for hard-to-heal wounds and common clinical conditions. 

To get oxygen from our lungs to our tissues, oxygen molecules bind to hemoglobin which is found in our red blood cells. As our blood moves through our microcirculatory system, oxygen is unloaded to the necessary tissues. When determining the healing capacity of a patient, blood flow, oxygen saturation and hemoglobin trends are extremely important markers.

How to use SnapshotNIR with three common clinical conditions

• Acute inflammation or infection

• Debridement

• Peripheral Arterial Disease (PAD)

Hemoglobin view on SnapshotNIR

SnapshotNIR, a handheld, portable, non-invasive device measures tissue oxygen saturation (StO2) using reflectance-based near-infrared light spectroscopy (NIRS). In Snapshot’s hemoglobin view, clinicians can look at StO2, the total hemoglobin and the relative amounts of deoxyhemoglobin (deoxy) – non-oxygen carrying molecules – and oxyhemoglobin (oxy) – oxygen-carrying molecules. This view gives an even deeper insight to guide clinician’s assessment and treatment plans.  

SnapshotNIR is the only NIRS device on the market today with the unique 4-panel Hemoglobin View (Hgb View). Underlying vascular disease is a significant comorbidity in wound care, and with SnapshotNIR you can use the Deoxy Hgb values and Oxy Hgb values in Hgb View to identify and document these conditions.

CASE 1 – Acute Inflammatory Infection

This patient presented to clinic with a painful, swollen right foot, exhibiting signs of local infection. SnapshotNIR can highlight the inflammatory area showing a ‘ruddy red’ color on Hgb View, specifically in the Total Hgb pane, indicating increased demand of O2 to that area. This is seen specifically on digits 3-5 in this case study. 

Common trends that may be seen in acute inflammation and infection: 

• StO2 may be high or normal in an acute infection 

• Elevated deoxyHgb

• Elevated oxyHgb

As the patient improves and inflammation reduces, the trend should be observed of decreased deoxyHgb and increased oxyHgb. 

Right images in the red boxes show increased deoxyHgb and oxyHgb indicative of acute inflammation. Case images courtesy of Kelly Roberts, NP.  

Case 1 images of StO2 show the tissue oxygenation in what would be considered a ‘normal’ range in the 70-80s (%), whereas Hgb View clearly shows the ‘ruddy red’ color in the total hemoglobin panel (bottom left), and oxyHgb and deoxyHgb have relatively high measures.

SnapshotNIR images, in this case, help provide evidence that an inflammatory process is occurring and can be used to monitor improvement of interventions such as antibiotics or warrant further investigation to rule out osteomyelitis. 

CASE 2 – Debridement Intervention 

Hgb View can be used pre-, post-, and during debridement interventions. StO2 may change and the ‘ruddy red’ inflammatory color should reduce. 

Sharp debridement is used to create a ‘new wound’ to encourage healing and remove at necrotic tissue. If there continues to be minimal change in deoxyHgb and oxyHgb, this may guide a clinician’s decision to continue debridement. 

Case 2 shows a patient after an orthopedic procedure of a bunionectomy with an unhealed wound at the surgical site. Pre-debridement, StO2 in the wound bed is 81% and there is an increase by 7% post-debridement. Even if a change in StO2 is not seen, there likely will be relative changes to total hemoglobin, deoxyHgb and oxyHgb giving the clinician objective evidence to the efficacy of the treatment. 

Pre debridement hemoglobin view. Red boxes highlight the oxyHgb and deoxyHgb values. Case images courtesy of Dr. Amy Couch, MD.

Post-debridement hemoglobin view. Note the relative changes in the red boxes in the oxyHgb and deoxyHgb values. Case images courtesy of Dr. Amy Couch, MD.

Common trends with debridement interventions seen in Hgb View on SnapshotNIR pre- and post-debridement interventions: 

• Increased oxyHgb  

• Decreased deoxyHgb  

• Reduced ruddy red color 

• StO2 can increase  

CASE 3 – Peripheral Arterial Disease 

In this patient with PAD, Hgb View was used to confirm occluded source arteries and the affected angiosomes, in conjunction with arterial doppler measures. The patient was pending a revascularization intervention due to occluded right Anterior Tibial and Posterior Tibial arteries, among others. The SnapshotNIR image in for this case example shows low StO2 between 42-57% in the angiosomes of note. 

In a patient with PAD, you may see these common trends in Hgb View:

• StO2 may be low 

• High deoxyHgb 

• Low oxyHgb 

• Low total hemoglobin 

Following revascularization, the common trend should occur with oxyHgb increasing and deoxyHgb decreasing. This patient was able to receive an expedited referral to a vascular surgeon for further assessment to determine if a revascularization procedure was warranted.  

For severe PAD and chronic limb-threatening ischemia (CLTI), Snapshot can be used to help direct and focus care, especially to vascular surgery. This can expedite their process, helping patients receive the care they need to reduce amputations. 

How can hemoglobin view help your practice?

The value in using hemoglobin view is that it provides additional metrics above and beyond just StO2.

When paired with the ease of SnapshotNIR’s repetitive imaging abilities, you can non-invasively track trends and compare Hgb values pre- and post-intervention at the bedside. Monitoring Hgb trends can help determine the healing potential of the patient’s tissues, facilitating faster wound closure and positive health outcomes.