51 - Yoho Case

Question 1

How did our patient for this case present?

Answer 1

o 30 year old female presents with painful hammertoe, wants surgery to fix this
o Allergies: penicillin; Medication: non
o Surgeries, C-section, tubal ligation, T&A, cholecystectomy
o Social: cigarettes, one pack per day for 10 years
o Family: history of a protein S deficiency associated with a blood clot in the leg, on blood thinners

Question 2

What were the pertinent review of systems for this patient?

Answer 2

o	GI (gallbladder surgery)
o	CV
o	Pulmonary
o	Endocrine
o	MSK (other than chief complaint)
o	Hematologic (see family history)

Question 3

What was found on the physical exam?

Answer 3

o Vascular, neurologic: normal
o Derm: hyperkeratotic lesion on sub-3rd metatarsal head, right foot
o MSK: plantar flexed 3rd metatarsal, right foot

Question 4

What is protein S?

Answer 4

o Protein S is a vitamin K-dependent plasma glycoprotein synthesized in the endothelium.
o S is named after Seattle where it was discovered (1979-1980)
o Manufactured in the liver
o Two forms - free floating or bound to protein C in the vasculature (for an anti-coagulative effect)

Question 5

How does protein S exert a anti-coagulant effect in the body?

Answer 5

o The C-S complex functions to stop the extrinsic clotting pathway
o Factors 5 and 8 get shut down by C-S

Question 6

What is the etiology of protein S deficiency?

Answer 6

o	Decreased (antigen) levels or impaired function (activity) of protein S leads to decreased degradation of factor Va and factor VIIIa and an increased propensity to venous thrombosis.
o	If you have a deficiency we are more likely to get thrombi

Question 7

What are the consequences of a protein S deficiency?

Answer 7

o The clinical presentation of PS deficiency includes deep venous thrombosis, superficial thrombophlebitis, and/or pulmonary embolism.

Question 8

What type of DVTs are likely to become a PE?

Answer 8

 DVTs above the knee tend to be the ones that break off, go to the lungs and they die

Question 9

Do patients with protein S deficiency always exhibit symptoms?

Answer 9

No - Protein S deficiency can be silent, can show up after an elective surgery when they are found dead

Question 10

What is a protein S deficiency possibly associated with?

Answer 10

White heart syndrome

Listen to recording for this?

Question 11

Describe the frequency of DVT leading to a VTE (venous thromboembolism)

Answer 11

o 50% first thrombotic events will occur before age 25

o 44% with provocations, 56% spontaneous

Question 12

What tests should you run on a patient with a family history of protein S deficiency before surgery?

Answer 12

o Order test for protein S deficiency – immunoassay (expensive)
o Liver tests (liver profile study)
o CBC with diff
o PPT, PTT, INR

Question 13

What are the two causes of protein S deficiency?

Answer 13

• Mutation leading to congenital form

- Acquired form

Question 14

What are the three types of congenital protein S deficiency?

Answer 14

Type I - decreased protein S activity: decreased total protein S (=both bound and free protein S) levels AND decreased free protein S levels (quantitative defect)

Type II - decreased protein S activity: normal free protein S levels AND normal total protein S levels (qualitative defect)

Type III - decreased protein S activity: decreased free protein S levels AND normal total protein S levels (quantitative defect)

Question 15

Describe an acquired protein S deficiency

Answer 15

• Much more frequent
• Seen in consumptive processes like DIC or extensive DVT/PE
• Seen in patients taking warfarin (other vitamin-K dependent factors)
• Seen in pregnancy
• Seen in liver disease

Question 16

What are the results of testing in our patient?

Answer 16

o Patient does have protein S deficiency
o If the patient is not in liver failure, pregnant or being anticoagulated, it is probably congenital and probably due to type I – just a lack of protein S deficiency

Question 17

What preventative measures should be taken when doing surgery on a patient with protein S deficiency?

Answer 17

o Wouldn’t use heparin at a level that was actually therapeutic, we would do “mini dose heparin”
o Don’t use a tourniquet around the thigh or calf, just around the ankle and don’t elevate it unless you really couldn’t do the surgery without it
o Minimize surgery time
o Warfarin after surgery, or just continue with the mini dose heparin
o Get them up and moving after surgery – early mobilization
o Monitor and tell them what to look for

Question 18

What is the take home message about this case?

Answer 18

o Need really good history taking skills
o See if there are any factors that need more consideration
o The history is the part that students really struggle with

Question 19

What was this patient’s outcome?

Answer 19

o A thin osteotomy was performed
o Elevated the area to take the pressure
o Hammer toe was rather flexible, so some soft tissue release was done as well
o The toe was straight after that

Question 20

What happened to this patient 6 months later?

Answer 20

o Patient had a DVT and was placed on anticoagulants for the rest of her life
o Because of the amount of time after surgery, it is not likely that this was because of the surgery
o She was overweight and not active, so this is likely part of the reason she had a DVT so early