Thrombolysis for acute pulmonary embolism in Chinese patients.

Sir, pulmonary emboli, weight-adjusted thrombolytic Acute pulmonary embolism is potentially fatal unless therapy was given. Patient 4 presented with syncope treated early. Thrombolytic therapy is beneficial for and shortness of breath. Electrocardiogram revealed patients with acute pulmonary embolism who are an S 1 O 3 T 3 pattern, and echocardiogram showed hypotensive and have arterial hypoxaemia1, and dilated right heart. Emergency spiral CT scan of those who are clinically stable but with echocardiothorax revealed pulmonary embolism in the right graphic evidence of right heart failure.2 However, in main pulmonary artery and distal branches. Weightthe Pulmonary Embolism Registry, the rate of major adjusted rtPA was given. bleeding was higher in patients receiving thromIn our centre, as emergency spiral CT is more bolytic therapy (21%) than in those on anticoagulreadily available than ventilation perfusion scanning, ation treatment (7.8%). In one study examining risk and is therefore used for diagnosing emergency cases. factors associated with bleeding in patients receiving Our four patients all had high clinical probability thrombolysis for pulmonary embolism,3 the relative of pulmonary embolism. All had echocardiographic risk of bleeding was 3.9 among patients aged >70 evidence of right heart dysfunction and arterial years compared with those aged <50 years. With hypoxaemia. The prompt improvement in oxygen age as a continuous variable, the risk of bleeding saturation and haemodynamic parameters of these increased by 4% for each additional year.3 The Food patients reflected the efficacy of the reduced dosage and Drug Association (FDA)-approved regimen of of thrombolytic therapy in resolving the pulmonary recombinant tissue plasminogen activator (rtPA) for emboli. Repeat spiral CT scans further supported the treatment of acute pulmonary embolism is 100 mg effectiveness of the treatment. as a continuous peripheral intravenous infusion over Despite the reduced dosage there were still bleed2 h.4 In our centre, we try to give a lower dose of ing complications in two of our patients. Our first rtPA for treatment of acute massive pulmonary embolpatient had abdominal pain after thrombolytic treatism in the elderly. ment. Emergency CT scan of the abdomen revealed We assume that the dosage of 100 mg rtPA is a retroperitoneal hematoma around the right psoas based on a 70 kg adult, and our recommended muscle. The dimension of the blood clot was about dosage is 80% of the dose, adjusted for patient’s 7 cm×8 cm. She was treated conservatively, but body weight. For example, for a 50 kg patient, had a significant drop in haemoglobin level, and dosage will be=100 mg×50/70×80% #60 mg. A four units of blood transfusion were required. Our cut-off age of 60 years as elderly is arbitrarily chosen. second patient suffered from bleeding around an From October 1997 to March 1998, we had four arterial puncture site. Crepe bandaging of the haemelderly patients who suffered from acute massive atoma site was performed and there was no significpulmonary embolism warranting thrombolytic ant drop in haemoglobin. therapy. Their characteristics and outcomes were In one study by Kanter et al.5 examining intracrasummarized in Tables 1 and 2. nial haemorrhage and associated risk factors in Our patient 1 presented with pleuritic chest pain patients with pulmonary embolism receiving thromand shortness of breath. Emergency spiral CT scan bolytic therapy, a retrospective analysis involving of the thorax showed major pulmonary embolism. 312 patients from different centres, the incidence of She was given weight-adjusted rtPA. Patient 2 preintracranial haemorrhage was 1.9% (six patients). sented with of shortness of breath. Emergency spiral Two of these six died. They identified increased CT scan of the thorax revealed major pulmonary diastolic blood pressure as a risk factor for intraemboli. Weight-adjusted rtPA was given. Patient 3 cranial haemorrhage (90.3±15.1 mmHg vs. presented with confusion and shortness of breath. Emergency spiral CT of thorax revealed major 77.6±10.9 mmHg, p=0.04).