GENERAL MEDICINE & POST-SURGICAL · CHAPTER 3 · LAB VALUES & MOVEMENT DECISIONS
An abnormal lab result isn’t the whole decision.
A hospital chart shows hemoglobin, potassium, creatinine, platelets, and more. Which number matters for the mobility session? The answer depends on the patient, the trend, and why the result is abnormal.
1. Start with the question, not just the flagged number
The General Medical and Post-Surgical lecture introduces a CBC, electrolytes, renal markers, coagulation results and fluid balance. A high or low result can signal a concern, but it cannot be interpreted without the diagnosis, treatment, reference range and trend.
A CBC includes hemoglobin and hematocrit (oxygen-carrying and blood-volume context), white blood cells (inflammatory or immune context), and platelets (hemostasis context). Red-cell indices can help describe an anemia pattern, but don’t independently diagnose its cause.
Ask whether the finding is new and changing, expected and being managed, or a stable known baseline. The same number may have very different meanings for two patients.
Quick check: A patient has a chronically abnormal result and was stable on prior sessions. Can you declare mobility safe from that history alone?
Reasoning: No. Look at the current trend, symptoms, team plan and response. Stable history is useful context, not automatic clearance.
2. What physiologic issue might affect movement?
Your course covers sodium, potassium, calcium and magnesium in fluid, nerve and muscle function. A potassium disturbance can have neuromuscular and cardiac implications; sodium abnormalities can accompany neurologic changes and fluid imbalance. They require medical interpretation, not a PT-created correction plan.
Creatinine and BUN provide renal and fluid-status context. Coagulation tests and platelets address different dimensions of bleeding risk. Some results are shaped by medications, chronic illness, blood loss, infection or current treatment.
One easy trap: edema does not necessarily equal adequate circulating volume. The notes distinguish total body fluid distribution from effective intravascular volume. It is possible to have swelling and still be intravascularly depleted.
Quick check: A patient has pronounced leg edema. Does that prove the circulation has more than enough effective fluid volume?
Reasoning: No. Edema may coexist with intravascular depletion or other conditions. Evaluate the medical explanation and clinical picture.
3. Choose the next step collaboratively
Consider the diagnosis, recent procedure, lab trend, medications or transfusion plan, symptoms, ordered activity, monitored response and facility policy. If a finding is critical or unclear for the planned task, clarify with the responsible team rather than relying on a universal PT lab cutoff.
Suppose a medically complex patient reports new unusual weakness and dizziness while their recent lab results are rapidly changing. That is not the moment to chase the planned walking distance. Help them into a safe position, reassess, and communicate or escalate in line with the care setting.
Document the result as context, the task attempted, relevant symptoms, assistance and the reason for your decision. Your notes’ most transferable lesson: trends and patient response matter more than memorized thresholds in isolation.
Quick check: The lab report is flagged, but you do not know the relevant treatment plan. What’s the safest reasoning step?
Reasoning: Interpret it with the patient’s presentation and clarify the medical plan or precautions with the team before making a clearance decision that the source doesn’t support.
Sources & learning scope
Based on the source companion, 3 | Lab values, fluids and electrolytes, incorporating the original CBC, fluid, coagulation and electrolyte lecture topics. The source also flags the APTA Academy of Acute Care’s updated lab interpretation resources (2023). This lesson does not provide universal clearance thresholds or independent medical treatment instructions.
Next topic: what tubes, drains and lines mean for bedside mobility planning.
Make the clinical connection
Scenario: A patient recovering from surgery has a hemoglobin value lower than yesterday and reports new fatigue during a short transfer. You know neither the current treatment plan nor the patient’s usual baseline.
What is the next reasoning step?
Reasoning: The falling trend and symptoms warrant context and appropriate team discussion before progressing. Do not use a single historical laboratory cutoff as independent medical clearance or as a diagnosis of why the patient feels weak.
Common mistake: Deciding an activity is universally safe or unsafe from the numeric value alone. Remember: Lab results guide questions; the medical plan and patient response guide decisions.
From My PT School Notes · Educational examples, not an individualized clinical protocol or an official exam-preparation product.
