The Anchoring Effect

Chief complaint: Abnormal bloodwork
HPI: 36 y/o female states she was sent in by PCP office for a drop in H/H. She was first seen 14 days ago, dx with pyelonephritis, and treated with a course of Augmentin. During her follow-up labs today, it was noted her HCT dropped from 31 to 25. She notes she is on her period x 5 days and goes through approximately 10 tampons a day. Denies weakness, lightheadedness, CP, SOB, abdominal pain, and bloody stools. No hx of similar symptoms.

ROS:
Constitutional: Negative for fever, chills
EENT: Negative for blurry vision, pain, sore throat
CV: Negative for chest pain, leg swelling, palpitations
Respiratory: Negative for cough, dyspnea
GI: Negative for nausea, vomiting, abdominal pain
GU: + for vaginal bleeding. Negative for dysuria, frequency
Musculoskeletal: Negative for pain
Skin: Negative for rash
Heme: Negative for easy bleeding, easy bruising

PMH: CHF, HTN, Obesity    Social: Nonsmoker

Exam:
P – 109.  Temp – 99.8.  R – 20.  BP – 145/68.  O2 – 99% on RA.
Weight: BMI 57
Constitutional: alert, no acute distress
EENT: PERRL, nares normal, pharynx normal
Respiratory: lungs clear, no distress
GI: nontender, soft
Rectal: guaic negative, QC+
MSK: full ROM x all extremities, no calf tenderness
Neuro: A&Ox3
Psych: normal affect
Skin: normal color, warm/dry

Differential Dx: Pyelonephritis, anemia

ED work-up. Labs and urine:

ED course and MDM:
Well appearing, NAD. Decrease in HCT likely due to menstrual period. Guiac neg. Not orthostatic.

Impression: 1) Anemia 2) Menstrual Period

Plan: DC home with PCP follow-up

Condition: Good

A cognitive pause is taking a moment to step back before final disposition to think about how all the pieces fit together. Can you find any red flags that warrant a cognitive pause or reason to expand the differential? Anchoring bias is relying too heavily on the first piece of information we are given. Anchoring on the H/H occurred. Could the ED physician have obtained other information to help discover the correct diagnosis?

What is not revealed or discussed in the ED chart above was why this patient went to her PCP in the first place. She initially presented to her PCP for LLQ abdominal discomfort with subjective intermittent fever. Her initial labs revealed a leukocytosis, anemia, and positive urine dip. The differential was pyelonephritis, PID, and diverticulitis. PID was lowest on the differential because the pain was only on her left side. Augmentin was chosen as it would treat a UTI as well as possible diverticulitis. On her 2-week follow-up (the appointment the day she was referred to the ED), she noted minimal improvement of her initial symptoms despite completion of the antibiotics and the pain was worse. Repeat labs were again abnormal. There was also a drop in her H/H, so she was referred to the ED. Written in the ED nursing triage note was the chief complaint: "treated by PCP for pyelo. Went back for follow-up and found to have low H&H and high WBC." Had the physician seen the triage note, they might have paused to further explore the elevated WBC.

Four days after the ED visit, the patient returned with 10/10 abdominal pain. CT revealed a large tubo-ovarian mass and significant free fluid in the pelvis. The plaintiff (the patient) alleged our failure to diagnose a tubo-ovarian abscess resulted in a worse infection, subsequent severe sepsis, a prolonged hospitalization, and further complications. Plaintiff experts were critical stating the ED physician failed to recognize an abdominal infection, failed to obtain a complete history, and failed provide a full evaluation that would have found the diagnosis. Defense experts had limited ability to support the care based on the discrepancy of symptoms in the span of two hours (between the PCP chart and the ED chart) and believed more could have been done for the patient; especially by way of obtaining a more thorough history and addressing abnormal laboratory studies (WBC) and vital signs (tachycardia). This case settled out of court.

Patient Safety Pearls

• Always take the cognitive pause.
• Beware of anchoring bias. The implicit reference to the first point of data.
• Patients with a significantly elevated BMI can be hard to evaluate due to exam limitations.
• Review available visit history that is relevant to the case at hand.
• Address abnormal labs in your MDM.
• Address abnormal vitals in your MDM.
• Review nursing notes and address discrepancies.
• If using templates, double check for accuracy, and personalize them to reflect the patient
• Always take the cognitive pause

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Survey Questions

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References