• A leg fracture, trauma, surgery, hospitalisation, and reduced movement are established risk factors for deep-vein thrombosis (DVT) and PE. A clot from the leg can travel to the lungs and cause sudden collapse or cardiac arrest. The CDC VTE guidance specifically lists leg fracture, major trauma, surgery, immobility, and prolonged bed rest as risk factors.
• Before an arrest, massive PE may cause sudden breathlessness, fast pulse, low oxygen, chest pain, fainting, or sometimes abnormal jerking that looks like a seizure. Emergency medicine texts note that PE causing cardiac arrest requires immediate consideration of thrombolysis or embolectomy, but recognition at the moment of collapse can be difficult.
• Thus, in this case, the “seizure” may have been a true seizure, or it may have been seizure-like movements caused by abrupt lack of blood flow and oxygen during a cardiac collapse.

1. A late post-traumatic seizure due to prior brain injury, scar, delayed subdural hematoma, hydrocephalus, or another intracranial complication.
2. Status epilepticus or seizure-related hypoxia/aspiration, leading to respiratory failure, severe acidosis, arrhythmia, and arrest.
3. Metabolic abnormalities, especially low sodium, calcium, magnesium, glucose, renal failure, or severe infection.
4. A primary heart rhythm problem, such as ventricular tachycardia, long-QT related arrhythmia, myocarditis, or an unrecognised inherited cardiac condition.
5. Medication or substance effects, including opioid/sedative toxicity, alcohol or benzodiazepine withdrawal, drug interactions, or medications that lower seizure threshold.
6. Less commonly, recurrent head bleeding, stroke, meningitis/encephalitis, severe bleeding, fat embolism, or severe sepsis.

Could it have been prevented?

• Was venous-clot risk assessed after the fracture, operation, and periods of immobility?
• Were mechanical methods, early mobilisation, and anticoagulant prophylaxis considered when safe?
• Was the duration of clot prevention appropriate for the type of fracture, surgery, mobility level, and bleeding risk?
• Did he have leg swelling/pain, shortness of breath, chest pain, fainting, unexplained fast pulse, or low oxygen before collapse?
• When the new seizure occurred, were airway, oxygenation, blood glucose, ECG/rhythm, electrolytes, CT brain, and PE considered promptly?
• What was the first arrest rhythm? Pulseless electrical activity is often seen with massive PE, but it is not diagnostic.
• Was there a CT pulmonary angiogram, leg Doppler, bedside echocardiogram, D-dimer when appropriate, or postmortem examination?
• Was there a delayed brain complication on CT/MRI?
• Which medicines, doses, recent anaesthesia, pain medicines, and substances were involved?

What to request now

• complete emergency, ward, surgery, and ICU records
• ambulance notes
• nursing observations and oxygen saturation charts
• ECGs and cardiac-arrest rhythm strips
• medication administration record
• CT/MRI brain reports and images
• blood results, including glucose, sodium, calcium, magnesium, potassium, blood gas, troponin, and coagulation tests
• VTE-risk assessment and thromboprophylaxis documentation
• any CT pulmonary angiogram, echocardiogram, or leg Doppler report
• death certificate and postmortem/autopsy report, if performed.