Lab Values And Vital Signs As Clinical Monitoring Tools For Patient Safety

Editor's note: This text-based course is a transcript of the webinar, Lab Values and Vital Signs as Clinical Monitoring Tools for Patient Safety, presented by Adele Myszenski, PT, MPT.

*Please also use the handout with this text course to supplement the material.

Learning Outcomes

• After this course, participants will be able to evaluate why lab values and vital signs are essential clinical tools for determining the appropriateness of acute care rehab intervention.
• After this course, participants will be able to analyze the normal values for BP, HR, SaO2, Hemoglobin, Potassium, Glucose, Platelets, Troponin, CPK, and other lab values while also analyzing the effects of abnormal lab values, including precautions and monitoring techniques.
• After this course, participants will be able to evaluate when to implement, modify, or hold rehab interventions based on assessment of lab values and vital signs.

Introduction

I’m based at Henry Ford Hospital in Detroit, Michigan, and I always like to start with a brief introduction to give you a sense of the setting I come from. We’re a Level 1 Trauma Academic Medical Center with a substantial ICU presence, alongside a robust general medicine service.

Laboratory diagnostic tests are an essential component in assessing a patient's overall health, particularly in the acute care setting. These tests evaluate critical organ systems, including the kidneys, liver, thyroid, and heart, among others. In acute care, some of the most frequently encountered blood tests during medical record review include the complete blood count (CBC), the differential, and the basic metabolic panel (also known as routine chemistry).

Importance of Understanding Lab Values: Normal and Abnormal

Normal values for these tests are generally based on the results observed in 95% of a healthy reference population. However, it’s important to recognize that normal ranges can vary depending on factors such as age, sex, race, and other individual characteristics. As rehabilitation therapists, we must be familiar not only with typical lab values and vital sign norms but also with how to monitor and interpret a patient’s physiological responses.

Laboratory results and vital signs form a crucial part of our clinical decision-making process during chart review. In a 2013 article, Dr. Amy Pollack and colleagues emphasized that patients experiencing acute illness require timely, accurate assessment and appropriate modification of activity by the treating physical or occupational therapist. This includes tailoring interventions to accommodate fluctuations in physiologic status.

Acute care therapists must choose interventions that optimize a patient’s performance, particularly across the oxygen transport system, musculoskeletal system, and neuromuscular system. Equally important is our understanding of the negative consequences of prolonged bed rest and the ways medical conditions can influence both physical function and cognition.

Furthermore, we must be able to recognize abnormal values—what they mean, and how they inform the care we provide. This webinar draws from a variety of sources, with evidence-based practice serving as the foundation of our clinical recommendations. Wherever possible, we’ve incorporated evidence-based guidelines relevant to a range of clinical situations, aiming to support sound and informed clinical judgment.

It's also vital to understand what constitutes a critical value. While most lab and vital sign parameters do not have strict cutoff points—or "hard stops"—there are more commonly what we consider "soft stops." For example, a borderline result may be flagged as critical based on clinical context.

Two useful definitions of a critical value help guide this understanding. In 2007, Lundberg defined it as a "physiologic state at such variance with normal as to be life-threatening unless something is done promptly, and for which corrective action can be taken." More recently, Pagana and colleagues described it as "an immediate health risk to the individual, requiring action on the part of the ordering physician."

As we assess lab results, it's important to consider whether a given value represents a red flag—something that warrants a pause or reassessment before proceeding with patient care.

When it comes to abnormal lab values and determining the appropriateness of rehabilitation interventions, many of the recommendations I'll share today are drawn from expert physician opinion. That’s because, for several lab parameters, high-quality research is still limited. You may also work alongside physicians who use their own institution-specific guidelines, and many of the general recommendations you'll hear today are exactly that—generalizations. It’s critical to have open, professional dialogue within your clinical team and to avoid using these values as strict “hard stops.”

Resources

To support this presentation, I’ve pulled from several trusted resources. First is the Lab Values Interpretation Resource, which was developed jointly by the APTA’s Academy of Acute Care and the Academy of Pediatrics. Today, we’ll focus specifically on adult parameters. This resource is comprehensive, detailed, and freely available to both OTs and PTs, regardless of APTA membership. A link is provided in the references section. Notably, all recommendations within this document are symptom-based rather than prescriptive, meaning they do not provide exact cutoff values for deferring or modifying treatment.

Another valuable resource is the Adult Vital Signs Interpretation Guide, published by the APTA in 2021 and available on their website. Lastly, I’ll be referencing the internal lab values manual developed at my institution, Henry Ford Hospital. This manual has evolved continuously over the past 25 to 30 years. It blends symptom-based guidelines with select numeric parameters, incorporating both clinical evidence and physician expertise. At Henry Ford, we prioritize a focused set of lab values that have direct implications for a patient’s medical stability.

For example, we do not typically defer PT or OT solely due to abnormal hematocrit or BNP levels. Instead, we closely monitor three core lab values across all patients: hemoglobin, potassium, and glucose. When these are out of range, it's often a signal that other lab values may be as well.

In this webinar, we’ll concentrate on lab values commonly seen among general unit patients rather than those in critical care. It’s important to remember that this content is meant to serve as guidance. All lab values and parameters presented today should be incorporated into your broader clinical decision-making process.

As we define key terms, review guidelines, and explore case examples, I encourage you to reflect on how these concepts apply to your own practice. During your initial chart review, pay close attention to lab and vital sign trends over time. Equally important is your ability to monitor a patient’s physiological response during therapy. For instance, you may need to reconsider treating a patient with abnormal vitals if you don’t have access to a blood pressure monitor, or if you're still developing confidence as a new graduate balancing lines, drains, Foley catheters, and all the nuances of an acute care setting.

In contrast, a more seasoned therapist may be better equipped to manage those complexities while simultaneously watching for subtle signs of physiological distress—changes in mentation, excessive sweating, or signs of intolerance to activity.

Other Considerations

Additional clinical considerations should always be considered in your decision-making. For instance, recent meals, IV infusions, or medications can affect lab values. Chronic conditions, such as anemia, may be well-tolerated during activity in some patients, while a sudden and significant drop in hemoglobin or hematocrit could signal a medical emergency.

Throughout this discussion, we’ll explore each key lab value in greater detail, always emphasizing that the clinical picture must be interpreted in context. That’s why clinical reasoning is at the heart of safe, effective practice. A foundational understanding of labs and vitals empowers you to perform a thorough medical record review, recognize significant trends, and engage in informed discussions with your team.

Documentation

Before diving into specific lab values, let’s briefly address documentation. As you make clinical decisions—both before and during interventions—it’s essential to document clearly and specifically. If you’ve consulted with the medical team and decided to proceed with treatment despite abnormal values, record your rationale, the parameters involved, and the patient’s response. Note any modifications made to your treatment approach. For example, if you conducted ADLs in a seated position due to orthostatic changes in blood pressure, be sure to include that context.

Lastly, when documenting vital signs during a session, always include the patient's position at the time of measurement and describe the activity they were engaged in. This detail provides important clinical context and supports sound clinical judgment.

Vital Signs

A solid baseline understanding of vital signs is essential in acute care, especially when lab values are abnormal. Normal resting vitals not only help confirm medical stability but also inform your decision to proceed, modify, or defer therapy on any given day. Resting values offer insight into a patient’s readiness for physical or occupational therapy, while monitoring during treatment can assess their hemodynamic and oxygenation response.

Vital signs should be monitored during specific situations to assess for adverse reactions, specifically related to blood transfusions or medication adjustments, and continuous monitoring of vital signs should occur for interventions in the intensive care unit.

Vital Signs (VS) at Rest

Normal resting values:

• Heart rate (HR): 50–120 beats per minute

• Systolic blood pressure (SBP): 80–180 mmHg

• Diastolic blood pressure (DBP): 40–110 mmHg

• Respiratory rate (RR): 12–18 breaths per minute

• Oxygen saturation (SpO₂): >90%

These are general population norms. Before beginning a session, always review the most recent vital signs in the chart and compare them to the patient's established clinical baseline. Ask yourself:

• Does this patient usually run hypertensive or hypotensive?

• What’s their typical resting heart rate?

• Do they require supplemental oxygen?

Examples

Here are a couple of examples of what you might see in your medical record for vitals. While your nursing staff may not document activity and positioning specifically, as I've instructed you to, you should assume that they were all taken at rest and likely in bed.

In this case, the patient's blood pressure is 88 over 45, which is concerning since the patient tends to have higher blood pressure. However, the most recent record was 113 over 56, which could be considered normal.

In this example, it's not just important to look at the latest and last; this patient actually trends closer to the last blood pressure of 94/52 than the 125/71, even though both are within normal limits. So if you were going to see the patient at 125 over 71, you may want to ask yourself, "Is this normal for this patient?" However, it is still within normal ranges.

Exceptions

There are exceptions to normal resting values that you should consider when deciding whether to proceed with or defer treatment. This is not an exhaustive list, but it highlights some common scenarios.

For instance, some surgical patients or those with bleeding risks, such as individuals who have undergone repair of an aortic aneurysm, may have intentionally lower systolic blood pressure or mean arterial pressure (MAP) targets. (Recall that MAP is the average pressure in a patient’s arteries during one cardiac cycle, typically calculated using both systolic and diastolic values.)

Patients recovering from ischemic stroke often exhibit permissive hypertension. In such cases, systolic blood pressures up to 220 mmHg and diastolic pressures up to 110 mmHg may be acceptable. Therapy should not be withheld solely based on these readings. 

Again, consultation with your clinical team is essential. Document any patient-specific permissible ranges to support your clinical decisions.

In cases of chronic hypotension, a MAP goal of 55 mmHg or greater may be appropriate. Patients with COPD might have target oxygen saturation levels as low as 88%, or even 85%, depending on physician guidance. Always consult the chart and speak with the care team to determine what is considered normal for each individual.

In some instances, heart rates up to 130 bpm at rest or up to 150 bpm with activity may be acceptable, particularly in patients with underlying cardiopulmonary conditions, cancers or metabolic diseases.

The key takeaway is individualized care. Avoid applying a blanket standard across all patients. While general resting values are helpful, they are not absolute.