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V/Q Lung Scan vs. Chest X-Ray and ABGs.....does increased or decreased suspicion dictate one route over the other..? ( so asks the MS 4 ....) thanks!
divinemsm said:V/Q Lung Scan vs. Chest X-Ray and ABGs.....does increased or decreased suspicion dictate one route over the other..? ( so asks the MS 4 ....) thanks!
GeneralVeers said:Always get a CXR on any patient with tachypnea, or hypoxia. This may lead to an alternative diagnosis like CHF or pneumonia which can explain the symptoms.
V/Q scan is rarely used anymore, as COPD, and other chronic disorders can lead to false positives or "intermediate probability" scans.
CT Pulmonary Angiography is the most commonly used method now. It's fast and easy to get. If I have an intermediate to high suspician of PE this is the first thing I get after CXR.
ABG, D-dimer have some utility, but are not specific enough to rule-in PE. A negative D-dimer does have high negative predictive value, however.
MushieCookie said:Does Spiral CT play a role in this anymore?
GeneralVeers said:Always get a CXR on any patient with tachypnea, or hypoxia. This may lead to an alternative diagnosis like CHF or pneumonia which can explain the symptoms.
V/Q scan is rarely used anymore, as COPD, and other chronic disorders can lead to false positives or "intermediate probability" scans.
CT Pulmonary Angiography is the most commonly used method now. It's fast and easy to get. If I have an intermediate to high suspician of PE this is the first thing I get after CXR.
ABG, D-dimer have some utility, but are not specific enough to rule-in PE. A negative D-dimer does have high negative predictive value, however.
waterski232002 said:Don't even think about ordering a d-dimer if the patient has multiple medical problems, big risk factors, or any inflammatory diseases.... just scan.
southerndoc said:There is research to suggest using a negative d-dimer AND a negative CT to exclude PE. It provides more security since CT has been reported to miss from 2-10% of PE's (radiologist and CT-generation dependent).
southerndoc said:CT has been reported to miss from 2-10% of PE's
waterski232002 said:I would argue, that these 2-10% of PE's "missed" by CT are insignificant anyways. If your patient has clinical signs consistent with PE (tachycardia, tachypnea, hypoxia, and/or significant SOB/CP), then this person does NOT have a tiny PE that will be missed by CT. So if the CT is negative, you better look elsewhere for your cause of distress. PE is NOT the major contributing factor in these cases.
Remember, it is not the PE that the patient currently has that is usually the killer. It's the one looming. Of course this doesn't apply if the patient has a large saddle embolus. However, if they are showering small PE's, duplex ultrasounds of the lower extremities can still miss deep venous thromboses in the pelvic veins.waterski232002 said:I would argue, that these 2-10% of PE's "missed" by CT are insignificant anyways. If your patient has clinical signs consistent with PE (tachycardia, tachypnea, hypoxia, and/or significant SOB/CP), then this person does NOT have a tiny PE that will be missed by CT. So if the CT is negative, you better look elsewhere for your cause of distress. PE is NOT the major contributing factor in these cases.
beyond all hope said:Relying on a negative D-dimer to r/o PE in the ED is a little ridiculous if you have a low clinical suspicion (yeah, this lady's got pleuritic chest pain and she's on BCPs but vitals normal and EKG normal. Could she have a PE?).
Seaglass said:"If your patient has clinical signs consistent with PE (tachycardia, tachypnea, hypoxia, and/or significant SOB/CP), then this person does NOT have a tiny PE that will be missed by CT. "
I think this is frankly untrue, or at least not something to rely on. PIOPED II also showed that arterial phase only CTPA is no so hot for detecting PE. It is important to find those small peripheral PEs because the next one might be the saddle embolus that kills you!
waterski232002 said:I don't know about you, but in the ER, I am more concerned about preventing my patient from decompensating acutely, than determining their need for anticoagulation on an outpatient basis (I didn't go into medicine for a reason).... that can be done at discharge when the patient is stable and feeling well. Keep them on their heparin gtt, and keep searching for causes.
We recently had a 28 yo patient in our ER who came in with tachycardia, tachypnea, and thigh pain after riding his bike. His thigh looked a little erythematous and warm, and we suspected DVT w/ PE. He had a negative CTPA, after the study came back negative, cardiac enzymes were sent, and his CPK's came back at 1500. Rhabdo was suspected next, then his diff came back with 27% bands and urine myoglobin was negative as the patient was started on BiPAP. X-rays of the femur showed no SC air. Plastics was consulted, and his leg wound began blistering open 3 hrs after triage... within 4 hrs of presentation he was coded and died. We could have easily just said, "well the CT is negative but this sounds like PE" without looking deeper. Nec Fasc is a bitch....
Seaglass said:Actually sounds a lot like the cases of Community aquired MRSA pneumonia that have been described.
12R34Y said:I agree. Was thinking the same thing. Usually nec fasc in an extremity lives quite a while (24-48 hours) in the ICU etc... and at least make it to surgery for debridement. Wonder why he would have a pure respiratory component from thigh infection?
the community acquired MRSA pneumonia sounds like it kills people very very quickly.
later
I was referring to discharge from the hospital after admission. Obviously a patient showing distress from a large PE or another respiratory complaint equivalent to it would never be discharged directly from the ER.southerndoc said:I look out for what's best for the patient, and that includes long-term anticoagulation when discharged from the ED. However, an unstable patient such as the one presented is unlikely to even be a consideration for discharge, even if the initial workup is negative.
No offense, but this was not a clear cut PE/DVT.