Heuristic Errors in Medicine:The Patient with a Red Eye

Richard K. Reed, M.D., F.A.C.P.

History

CC: Problem with right eye PI: RJ is a 40 yo female with Downs

Syndrome with itching of the right eye for 3 days. She had associated pain in the eye. Her caregiver could not restrain her from rubbing the eye. There was no known history of trauma to the eye. She had no recent URI symptoms.

PMH

Downs Syndrome – functions as 3 yo Leukemia as a child Stroke as result of complication of chemotherapy

for leukemia Obesity Hypertension Hyperlipidemia Primary hypothyroidism Sleep apnea

Social History

Medications: - HCTZ 25 mg. daily - Lisinopril 10 mg. daily - Levothyroxime 100 mcg. daily - Lovastatin 40 mg. daily - Citalopram 20 mg. daily - D3 2000 units daily - B12 1000 mcg daily

NKA No alcohol, tobacco, or other drug abuse Needs help with most ADLs

Family History

Father – died recently of complications of diabetes, renovascular hypertension, chronic renal disease, ischemic heart disease

Mother – died in 1980s of metastatic breast cancer

Aunt – died recently of complications of diabetes and heart failure

ROS

No recent URI symptoms No headache No fever No known head or eye trauma No known abuse issues

Physical Examination

BP 130/80 Pulse 64 RR 16 Temp 97.4 Weight 170# Height 4’7” BMI 39.5 kg/m2 No known narcotic or elicit drug use No tobacco use

Physical Examination cont.

Gen – obese, Downs phenotype, constantly rubbing her right eye

HEENT -visual acuity – not able to access -examiner difficulty on observing right eye -right eye red with conjunctival suffusion -brief look at cornea- no problem -fundus exam impossible -fluorescein staining – NA -slit lamp exam - NA

Physical Examination cont.

Neck – short Chest – clear Heart – RRR with no murmur Abdomen – obese, no organomegaly Extremities – mild pretibial edema Neuro – wheelchair bound; residual neurologic

sequelae of mild left hemiparesis

Assessment

Right red eye – conjunctivitis, iritis or corneal abrasion

Downs Syndrome Obesity

Plan

Unsure of correct diagnosis, I referred her to an ophthalmologist.

Clinical Course

Ophthalmologist

1. He did eye exam the following morning and prescribed eye drops.

2. She returned to see him in 4 days. a. Ophthalmologist was apparently unable to adequate exam. b. With suspicion for underlying pathology, he took her to surgery for exam under anesthesia and found a corneal perforation. c. Evisceration (not enucleation) procedure was performed. d. Prosthetic ball was placed into scleral husk

Later Clinical Course

Patient would not leave eye guard in place. The ophthalmologist subsequently removed

the ball from the scleral husk. The scleral husk was left in place and will

atrophy.

Question

Any ideas as to what was the underlying problem with this patient’s eye?

Diagnosis

Keratoconus

Corneal hydrops

Corneal perforation

Keratoconus

Munson’s Sign

Corneal hydrops

Pathology

Downs Syndrome - - - keratoconus

Keratoconus - - - corneal hydrops

Corneal hydrops - - - corneal perforation

What went wrong?

My lack of knowledge

Ophthalmology consultation timing

Ophthalmology

Patient factors

Cognitive Illusions

The hot road illusion

The retrospectroscope:

Hindsight is always 20/20 vision.

“You can see more by looking.” - Yogi Berra

Diagnostic Errors with Clinical Heuristics

Availability heuristic errors Anchoring errors Framing errors Blind obedience Premature closure Faulty or inadequate knowledge

Back to the Patient with the Red Eye

Availability heuristic errors Anchoring errors Framing errors Blind obedience Premature closure Faulty or inadequate knowledge

The Swiss Cheese Analogy

Systems related errors

Cognitive errors

The Doctor, by Sir Luke Fildes

Words of Wisdom

There is nothing more humbling than the practice of medicine.

Continuing Medical Education

Bibliography

googleimages.com IMB3641 65 low jpg (picture of corneal hydrops)

googleimages.com CLS0610 (picture of Munson’s sign)

Graber ML, Franklin N, Gordon R. Diagnostic Error in Internal Medicine. Arch Intern Med. 2005;165(13):1493-1499. [PMID:16009864].  

Grewal S, Laibson PR, Cohen EJ. Acute hydrops in the corneal ectasias: associated factors and outcomes. Trans AM Ophthalmology Society 1997; 97:187-203.

Groopman J. How Doctors Think. 2008. Houghton Mifflin

http://www.cornea.org (picture of keratoconus)

MKSAP 15, American College of Physicians

Redelmeier DA. Improving patient care. The cognitive psychology of missed diagnoses. Ann Intern Med. 2005;142(2):115-120. [PMID:15657159].  

Rothschild JM, Landrigan CP, Cronin JW, et al. The Critical Care Safety Study: The incidence and nature of adverse events and serious medical errors in intensive care. Crit Care Med. 2005;33(8):1694-1700. [PMID:16096443].  

Tuft SJ, Gregory, Wm, Buckley RJ. Acute corneal hydrops. Ophthalmology: Oct. 1994:1738-44.

Vidyarthi A, Arora V, Schnipper J, Wall S, Wachter R. Managing discontinuity in academic medical centers: strategies for a safe and effective resident sign-out. J Hosp Med. 2006;1(4):257-266. [PMID:17219508].