Intraop Pulmonary Embolism — Recognition + Management

Long bone fracture fixation.

Cancer surgery (esp pelvic, abdominal, brain).

Prolonged immobility.

Known DVT, hypercoagulable states (Factor V Leiden, antiphospholipid syndrome, malignancy, hormonal therapy, prior VTE), obesity, age >70, pregnancy.

Cement-implantation syndrome in hip arthroplasty combines fat + marrow embolism with PE physiology — multimodal embolic load with similar presentation.

Concurrent hypotension + tachycardia.

Hypoxemia (often modest unless massive).

Increased CVP + JVD.

New right bundle branch block, S1Q3T3 pattern, or T-wave inversions V1-V4 on ECG.

TEE intraop is the most useful real-time tool: direct clot visualization in RV outflow tract or main pulmonary artery (rare), RV dilation, RV free-wall hypokinesis with apical sparing (McConnell's sign — relatively specific), septal flattening + D-shaped LV, tricuspid regurgitation with elevated estimated PASP, dilated IVC.

VAE is the main differential — bubbles on TEE point to VAE, no bubbles + RV strain pattern point to PE.

Post-op (if patient stabilizes + transport is feasible): CT pulmonary angiography is the gold standard — sensitivity + specificity >95%.

V/Q scan if contrast contraindicated.

Treat the most likely diagnosis empirically when imaging delay would be dangerous.

Avoid hypoxia + hypercarbia + acidosis — all worsen pulmonary vasoconstriction + RV afterload.

Norepinephrine 1st line for hypotension; epinephrine if mixed RV failure + vasoplegia.

Vasopressin 0.04 units/min as adjunct — supports SVR without raising PVR.

Inotropic support: milrinone or dobutamine for RV failure, though both can drop SVR.

Inhaled nitric oxide 20-40 ppm or inhaled epoprostenol selectively reduces PVR without systemic vasodilation — useful adjuncts.

Fluid resuscitation is a two-edged sword: small bolus (250-500 mL) may help underfilled RV, but over-resuscitation distends the RV further + worsens septal-shift LV compromise.

Heparin bolus 80 units/kg + infusion is reasonable if the surgical bleeding risk is acceptable + the surgeon agrees — most commonly possible if surgery is nearly complete or hemostasis is achieved.

Systemic thrombolysis (tPA 50-100 mg) is reserved for ARREST FROM CONFIRMED MASSIVE PE — the bleeding risk intraop is catastrophic + nearly always prohibitive.

Catheter-directed thrombolysis or thrombectomy via interventional radiology is preferred when massive PE confirmed + surgical bleeding precludes systemic lysis.

ECMO (VA configuration) bridges patients to definitive therapy when available.

Continued therapeutic anticoagulation as soon as surgical bleeding allows — typically heparin bridge then DOAC or warfarin.

Duration: minimum 3 months provoked, lifelong for unprovoked + recurrent + persistent risk factors.

IVC filter indication: confirmed PE/DVT with absolute contraindication to anticoagulation (active surgical bleeding) — retrievable filters preferred, removed when anticoagulation can be started.

Hypercoagulable workup if unprovoked.

Long-term: pulmonary hypertension follow-up at 3-6 months — chronic thromboembolic pulmonary hypertension develops in ~3-4% of survivors + may be candidate for pulmonary endarterectomy.