Deep venous thrombosis

Vignette says a 50 year old male presents to the emergency department with chief complaints of right calf pain and selling on the 3rd postoperative day; He recently underwent open cholecystectomy for acute cholecystitis 3 days back; He has a history of hypertension for which he takes amlodipine; Examination shows right calf tenderness on palpation; Vital signs show blood pressure of 120/80 mm of Hg, pulse rate of 88 bpm, respiratory rate of 18 breaths/min, oxygen saturation of 92% in RA and temperature of 97.9 F; D-dimer is positive; Duplex ultrasound of the right lower extremity shows thrombus, filling defects and lack of compressibility; Diagnosis?

Diagnosis is Deep venous thrombosis (DVT).

Presents with calf pain, tenderness and swelling; The patient might develop low grade fever, acute onset SOB, tachycardia, tachypnea and pleuritic chest pain if pulmonary embolism occurs secondary to deep venous thrombosis; Homans's sign is positive (i.e. calf pain at dorsiflexion of the foot).

Risk factors:-
1. Stasis
2. Endothelial injury
3. Hypercoagulability

Wells Score for DVT (used to stratify the likelihood of DVT):- A score of 3 or more suggests a high likelihood of DVT, whereas a score of 1 or 2 indicates moderate probability and a score of 0 suggests low likelihood.

Diagnosis:-
1. D-dimer is positive.
2. Duplex ultrasound of the lower extremity shows filling defects, lack of compressibility, thrombus and dilated veins.

Management:-
1. Anticoagulation (e.g. LMWH) followed by warfarin or direct oral anticoagulants (e.g. apixaban, rivaroxaban).
2. Compression stockings to prevent post-thrombotic syndrome and reduce swelling.
3. Thrombolytics (Symptomatic iliofemoral DVT).
4. IVC filters are indicated if anticoagulation is contraindicated or if emboli are occurring despite adequate anticoagulation.
5. Evaluate for underlying risk factors (e.g. malignancy, thrombophilia).
6. Prevention strategies of DVT includes:-
a. Pharmacologic: Prophylactic LMWH or fondaparinux. 
b. Mechanical: Sequential compression devices (SCDs) and graduated compression stockings. 
c. Early ambulation post-surgery is also an important strategy to reduce stasis.