Which findings in the examination of the synovial fluid are consistent with a diagnosis of rheumatoid arthritis?

Case Study: Rheumatoid Arthritis
Patient’s Chief Complaints and History of Present Illness:
M.L. is a 50-year-old white female who has been working in the front office of a medical clinic for the
past five years. She has made an appointment to see her primary care provider because she has been
feeling very tired for the past month and has also been suffering from stiffness, pain, and swelling in
multiple joints. “I ache all over,” she told her PCP, “and I have pain in different places all the time. One
day it is in my right shoulder, the next day in my right wrist, and the following day in my left wrist. I’m
stiff everywhere when I get up in the morning or if I sit for any length of time. And I feel so tired, like I
have a case of the flu that won’t go away.”
The patient is allergic to IV iron dextran from which she has developed shortness of breath. She rarely
uses alcohol and does not smoke. She is taking an over-the-counter calcium supplement, levothyroxine
sodium, and venlafaxine. There is no family history of rheumatoid arthritis.
Physical Examination and Laboratory Tests
The patient is pleasant and alert, but appears very tired. She is in moderate acute distress from joint
pain. Vital Signs BP 125/80 left arm, sitting; P 80; RR 15; T 100.0°F; Ht 54; Wt 140 lbs.
Patient Case Question 1. Which of the vital signs above is consistent with a diagnosis of rheumatoid
arthritis and why?
Patient Case Question 2. List two conditions for which the drug venlafaxine is often prescribed.
HEENT • Head atraumatic • PERRLA • Normal funduscopic examination • EOMI • TMs intact Skin •
Intact, warm, pink, and dry • No rashes • Normal turgor Neck • Supple with no jugular vein distension or
thyromegaly • No bruits • Mild lymphadenopathy bilaterally
Lungs • Clear to auscultation and percussion Heart • RRR • Normal S1, S2; no S3 or S4 • No murmurs,
rubs, or gallops
Abdomen • Soft, non-tender, and non-distended • Positive bowel sounds throughout • No superficial
veins or organomegaly
Breasts No lumps, dimpling, discharge, or discoloration
Genitourinary • Last menstrual period 16 months ago • Normal pelvic exam and Pap smear
Neurologic • Alert and oriented x 3 • Cranial nerves II–XII intact • Muscle strength: 5/5 upper
extremities, 4/5 lower extremities • DTRs 2+ in biceps, triceps, and patella
Rectal Heme-negative stool
Patient Case Question 3. Identify two abnormal findings from the physical exam above that are
consistent with rheumatoid arthritis.
Musculoskeletal, Extremities • No clubbing or ankle edema • Hands: Swelling of the 3rd, 4th, and 5th PIP
joints bilaterally; pain in the 4th and 5th MCP joints bilaterally; poor grip strength bilaterally • Wrists:
Good range of motion, fixed nodule at pressure point on left side • Elbows: Good range of motion, fixed
nodule at pressure point on right side • Shoulders: Pain and decreased range of motion bilaterally •
Hips: Good range of motion • Knees: Pain, significant edema, and decreased range of motion bilaterally
• Feet: No edema, full plantar flexion and dorsiflexion and full pedal pulse bilaterally Patient Case
Question 4. What is the association between the “fixed nodule(s) at pressure point(s)” on the left
wrist/right elbow and a diagnosis of rheumatoid arthritis?
Patient Case Question 5. Why is it reasonable that this patient has no stiffness, pain, or swelling in the
DIP joints of the fingers?
Laboratory Blood Test Results
Na 140 meq/L
ANA Negative
Hct 43%
Uric acid 2.9 mg/dL
K 3.7 meq/L
ESR 38 mm/hr
WBC 15,100/mm3
Cholesterol 189 mg/dL
Cl104 meq/L Cr 1.0 mg/dL
Plt 270,000/mm3 Albumin 4.0 g/dL
HCO3 23 meq/L
Glucose, fasting 94 mg/dL
RBC 4.7 million/mm3
TSH 1.7 μU/mL
BUN 18 mg/dL Hb 14.9 g/dL
Ca2 8.8 mg/dL
RF Positive
Patient Case Question 6. Identify three abnormal laboratory tests in Table 80.1 that are consistent
with a diagnosis of rheumatoid arthritis.
Patient Case Question 7. Why is it entirely appropriate that the PCP has ordered a TSH test for this
patient?
Patient Case Question 8. Provide a reasonable explanation for the serum uric acid test result shown in
Table 80.1.
Patient Case Question 9. What is probably the first class of drugs that the PCP will prescribe for this
patient?
Urinalysis Normal with no RBC, WBC, or protein
Chest X-Ray No fluid, masses, infection, or cardiomegaly
Hand X-Ray Soft tissue swelling and bone demineralization; no erosions
Synovial Fluid Analysis (Left Knee) • 7.4 mL volume • Cloudy and yellow in appearance • 14,000
WBC/mm3, primarily neutrophils • Glucose: 60 mg/dL
Patient Case Question 10. In terms of the progression of the disease, what do the results of the hand
x-ray suggest?
Patient Case Question 11. Which findings in the examination of the synovial fluid are consistent with a
diagnosis of rheumatoid arthritis?
Patient Case Question 12. What causes limitation of joint motion that occurs early in the clinical
course of rheumatoid arthritis?
Patient Case Question 13. What causes limitation of joint motion that occurs late in the clinical course
of rheumatoid arthritis