Continuous Oxygen Monitoring Improves Post-Surgery Outcomes | Wake Forest Study

Continuous monitoring of oxygen levels after major surgery, using wearable sensors, appears to significantly reduce the time patients spend with dangerously low oxygen saturation compared to standard, intermittent checks. A new study from Wake Forest University School of Medicine suggests this approach could improve recovery and potentially lower the risk of complications, though further research is needed to confirm these benefits.

The Challenge of Postoperative Hypoxia

Maintaining adequate oxygen levels is crucial for healing after surgery. However, many patients experience periods of hypoxia – a deficiency in oxygen reaching the tissues – during their recovery. This can impair wound healing, increase the risk of infection, and contribute to other adverse outcomes. Traditionally, hospitals have relied on periodic “spot checks” of oxygen saturation using pulse oximetry to identify and address hypoxia. This new research questions whether continuous monitoring offers a substantial advantage.

The Wake Forest study, published in August 2025, involved 1355 adult patients undergoing major noncardiac surgery. Researchers continuously tracked oxygen saturation levels for up to 48 hours postoperatively, or until discharge. They then compared the amount of time patients spent with an oxygen saturation below 90% – a level considered potentially harmful – between those with continuous monitoring and those managed with standard care. The study found that, on average, patients experiencing at least one component of a composite outcome (surgical site infections, sepsis, pneumonia, or in-hospital mortality) had a significantly higher cumulative time with oxygen saturation below 90% compared to those who did not experience these complications. However, the study ultimately found no statistically significant association between the *amount* of time spent below 90% saturation and the overall composite outcome.

What Does Continuous Monitoring Actually Measure?

Pulse oximetry, the technology used in both spot checks and continuous monitoring, is a non-invasive method for estimating the percentage of hemoglobin in the blood that is carrying oxygen. A pulse oximeter clips onto a fingertip or earlobe and shines light through the tissue. Different forms of hemoglobin absorb light differently, allowing the device to calculate oxygen saturation (SpO2). While a valuable tool, pulse oximetry isn’t perfect. Factors like poor circulation, nail polish, and certain medical conditions can affect its accuracy. The Wake Forest study accounted for some of these factors in its analysis, but acknowledges inherent limitations in the technology.

Beyond Oxygen Saturation: The Role of ECMO

For patients experiencing severe respiratory or cardiac failure, another advanced technology – extracorporeal membrane oxygenation (ECMO) – can provide even more intensive support. ECMO, offered at Wake Forest Baptist Health, essentially takes over the function of the lungs and heart, circulating and oxygenating blood outside the body to allow the organs to rest and heal. While ECMO is reserved for the most critical cases, it highlights the broader spectrum of interventions available to address oxygen-related complications after surgery. It’s important to note that ECMO doesn’t cure the underlying disease, but provides vital support during the recovery process.

Hyperbaric Oxygen Therapy: A Different Approach to Wound Healing

Another oxygen-based therapy, hyperbaric oxygen therapy (HBOT), is used to promote healing in chronic, non-healing wounds. HBOT involves breathing 100% oxygen inside a pressurized chamber, increasing the concentration of oxygen in the bloodstream and delivering it to damaged tissues. This can assist reduce swelling, fight infection, and stimulate the growth of new blood vessels. While distinct from continuous monitoring, HBOT represents another way clinicians leverage oxygen to improve patient outcomes.

Study Limitations and What They Mean

The Wake Forest study, while valuable, has limitations. The researchers found no statistically significant association between the amount of time spent with low oxygen saturation and adverse outcomes. This doesn’t necessarily mean continuous monitoring is ineffective; it suggests the relationship may be more complex than initially hypothesized. The study’s design focused on a composite outcome, meaning it looked at a combination of different complications. It’s possible that continuous monitoring might be more beneficial for preventing specific complications, but this wasn’t detected in the overall analysis. The study only tracked patients for a limited period postoperatively. Longer-term effects of hypoxia and the potential benefits of continuous monitoring remain to be investigated.

What Comes Next: Refining Postoperative Care

The findings from this study are likely to prompt further investigation into the optimal strategies for monitoring and managing oxygen levels after surgery. Researchers may explore whether continuous monitoring is particularly beneficial for specific patient populations (e.g., those with pre-existing lung conditions or undergoing complex surgeries). Future studies could also investigate the impact of continuous monitoring on individual complications, rather than relying on a composite outcome. Hospitals may also refine their protocols for responding to low oxygen saturation alerts generated by continuous monitoring systems, ensuring timely and appropriate interventions. The goal is to identify the most effective and efficient ways to ensure patients receive the oxygen support they need to recover safely and successfully.