a) I ll do rapid assessment by history and examination.I ll keep high index of suspicion for pulmonary embolism.I ll ask for personal history or family history of VTE,history of any known thrombophilia and drug history,history of associated symptoms like hemoptysis,radiation and location of pain,cough.I ll do examination for pulse,BP,JVP,oxygen saturation,chest auscultation, BMI.I ll inform consultant obstetrician and involve physician.I ll start oxygen inhalation by face mask and have IV access.I ll take blood sample for all investigations likeFBC,arterial blood gases,coagulation profile,urea,creatinine and electrolytes,LFTs.I ll ask for XRAY chest urgently.I ll do ECG and ask for urgent echocardiogram within one hour of presentation.My differential diagnosis in the order of priority will be pulmonary embolism,aortic dissection,myocardial infarction,pneumothorax and pneumonia.I ll reach some provisional diagnosis by this assessment and start therapy while waiting for further investigations to confirm the diagnosis.I will start therapeutic dose of unfractioned heparin for PE according to unit protocol as it should be started on strong clinical suspicion while waiting for confirmatory tests b) For a definite diagnosis I ll ask for compression duplex scan for legs to rule out DVT.If it is +ve diagnosis of PE is confirmed but a negative scan does not rule out PE.I ll ask for CTPA or V/Q scan for PE.for this I ll inform woman about both tests and do either one of these after informed consent.CTPA exposure to pregnant breast causes increased life time risk for breast cancer especially in obese pts. and inthose with family history of breast cancer.CTPA cant detect small peripheral emboli.It gives low radiation exposure for fetus.V/Q scan exposes the fetus to high radiation dose and causes increased risk for childhood malignancies and leukemia.V/Q scan has high negative predictive value for PTE and also low radiation dose for pregnant breast tissues.Other investigations like D dimer is of no diagnostic value in pregnancy.Thrombophilia screen is difficult to interpret in pregnancy as protein S is reduced and activated protein C resistance may increase in normal pregnancy.antithrombin may be reduced in extensive thrombus so should be interpreted by an expert if done in pregnancy.
