A nurse is caring for a patient who received a blood transfusion 2 hours ago. Which assessment finding would be the most important indicator of a potential transfusion reaction?

Temperature elevation with chills is a classic sign of a febrile transfusion reaction, requiring immediate intervention like stopping the transfusion. Other findings like mild BP or HR changes are less specific and may not indicate an urgent reaction.

Understanding the Clinical Scenario
The patient is 2 hours post-blood transfusion. This timing places the patient squarely within the window for an acute transfusion reaction (ATR), which is defined as any unfavorable response occurring during or within 24 hours of blood component administration ^[2]. The nurse's priority is to identify the most critical indicator of a potential reaction, distinguishing it from less specific or less urgent clinical changes.

Analysis of Assessment Findings
The core of this question lies in recognizing the classic and most common presentation of a potentially serious acute reaction versus expected or nonspecific variations.

* Option 1: Temperature increase from 98.6°F to 101.2°F with chills
This finding is the hallmark of a febrile non-hemolytic transfusion reaction (FNHTR) and can also be an early sign of a more severe acute hemolytic transfusion reaction. The literature identifies fever and chills as primary presenting symptoms of acute transfusion reactions ^[1]. A temperature spike of this magnitude, especially when accompanied by chills, is a highly specific and concerning indicator that demands immediate cessation of the transfusion and further evaluation. In studies of pediatric transfusion reactions, febrile reactions are consistently among the most frequently reported types .

* Option 2: Blood pressure decrease from 120/80 to 110/70 mmHg
A slight drop in systolic blood pressure by 10 mmHg is a relatively minor change. While hypotension can be a feature of severe reactions like anaphylaxis or sepsis, this isolated, modest decrease lacks the specificity and severity to be the most important indicator when compared to a significant fever with chills.

* Option 3: Heart rate increase from 78 to 88 beats per minute
A mild sinus tachycardia of an increase of 10 beats per minute is a very nonspecific finding. It could be related to anxiety, mild volume shifts, or a reaction. In the context of a transfusion, it warrants monitoring but is not the most definitive or urgent sign of a reaction when compared to a febrile response.

* Option 4: Oxygen saturation decrease from 98% to 96%
A drop in oxygen saturation by 2% is a subtle change that can occur with patient movement or transient fluid shifts. While a more dramatic desaturation would be a critical sign of transfusion-associated circulatory overload (TACO) or transfusion-related acute lung injury (TRALI), this minor decrease is not the most immediate or specific indicator of a reaction in this early phase ^[1].

The Priority Nursing Judgment
The most important indicator is the significant temperature elevation with chills. The classification of transfusion reactions begins with the timing of onset, and the acute period is where vigilant monitoring for symptoms like fever is critical ^[1]. A rise in temperature is a sentinel sign that triggers the immediate nursing action protocol: stop the transfusion, maintain the IV line with normal saline, monitor vital signs, and notify the provider. The other options represent changes that are either too subtle, nonspecific, or not the classic, most frequent initial indicator of a potentially life-threatening acute hemolytic reaction or a common FNHTR ^[2].