Avoiding Pitfalls In PE

Transcription

1 UC SF Avoiding Pitfalls In PE Jeffrey Tabas, MD Professor UCSF School of Medicine Emergency Department San Francisco General Hospital sf g h Disclosure No Financial Relationships to Disclose No significant investments or savings Unlimited Expenses PreTest Probability PERC/D-dimer Radiology Treatment OUTLINE Are we spotting the clots without radiating the entire lot? 1. Are we assigning a pretest risk? - Low, Moderate, or High 2. Are we limiting radiation /contrast with the PERC rule and D-Dimers? 3. Do we understand the use of helical CT? 1

2 CASE #1 38 y.o. F, sudden onset, burning SSCP x 3 hrs Not pleuritic, positional, or radiating. No SOB No meds, Not a smoker, No other PMHx NAD, 120/80, 80, 18, 37.1, 96% Exam unremarkable ECG Normal CXR - Clear Risk Factors for Thromboembolism Family History Cancer CHF Prior thromboembolism Estrogen use / Pregnancy / Obesity Low Abdominal/Pelvic surgery/trauma < 6 mos LE Paralysis/ Immobility / Trauma Pain improved with viscous lidocaine and mylanta Risk Factors - Pearls Symptoms Signs Risk Factors increase your suspicion However 20% of patients with PE have no known Risk Factors Therefore Lack of Risk Factors by no means excludes PE Dyspnea = 73% v 59% RR > 20/min = 70% v 68% Pleuritic Pain = 66% v 43% Rales = 51% Cough = 37% v 25% Tachycardia = 30% v 23% Leg Swelling = 28% Loud P2 = 23% Leg Pain = 26% Temp > 38.5C = 7% v 17% Hemoptysis = 13% v 7% Wheezes = 5% Stein, Chest, 91 Miniati, Am J Resp CC Med, 99 2

3 Symptoms / Signs 97% with PE had at least ONE of the following Dyspnea Tachypnea Pleuritic pain Stein, Chest, 91 Signs/Symptoms - Pearls Dyspnea, Tachypnea, or Pleuritic CP the Triggers! History and Physical Exam Pitfalls Hx of VTE, surgery, leg swelling, estrogen use O2 Sat & Respiratory Rate - Measure yourself Examine and even measure the extremities Don t misinterpret non-specific findings (ex. Partially reproducible pain => Costochondritis) Most Recent Data Symptoms / Signs/ Risk Factors Courtney, AnnEM, Risk Factors/Signs/Sx s in 7940 ED pts Strongest predictors for PE (OR > 2): Hx of VTE Unilateral Leg Swelling O2 Sat < 95% Estrogen Use Surgery (GA) w/in 4 weeks EKG S Q Non-specific Tests Useful when it provides alternate Dx S1Q3T3 (+LR=3.7) Inverted T waves in V1-V4 (+LR=3.7) CXR Useful when it provides alternate Dx THampton s Hump, Westermark s sign 3

4 When Do I Start the Workup? When there is 1 of 3 findings: Dyspnea Tachypnea Pleuritic Chest Pain And no definitive alternate diagnosis CASE #1 - Review 38 y.o. F, sudden onset, burning CP x 3 hrs Not pleuritic, positional, or radiating. No SOB No meds, Not a smoker, No other PMHx NAD, 120/80, 80, 18, 37.1 Exam unremarkable ECG Normal, CXR Clear Resolved with GI Cocktail. Discharged home How Do I Choose a Risk Category? Gestalt vs Risk Factors Symptoms and Signs Presence of Alternate Diagnosis Clinical Decision Rules The Pitfall of Risk Stratification Pretest Probability Kline, JTH ED pts Low (2-15%) 3% Moderate (15-40%) 10% High (>40%) 31% 4

5 Clinical Decision Rules There Are Lots of Them Wells, Ann IM, 98 We don t remember them Runyon et al., Wells, Thr Haemo, 00 Acad EM, 2007 Wicki, Arch IM, 01 Kline, Ann EM, 02 Miniati, AM J Med, 03 Cinical Decision Rules They Don t Agree With Each Other Wells Wicki Kline Miniati HR > (HR/SBP) Immobile/Surgery Hx VTE Hemoptysis Advanced Age S/S of DVT + + Hypoxia + + Alternate Dx + Cancer + Risk Stratification - Pearls Gestalt appears equivalent to Algorithms Algorithms may be beneficial for trainees Algorithms may be beneficial for institutional uniformity The PERC rule PERC rule (like d-dimer) can eliminate the need for imaging Not a Clinical Decision Rule Apply AFTER Risk Strat Apply ONLY to Patients you have stratified as Low Risk If negative, no further evaluation is needed Kline, JA et al. JTH ED pts, 7% with VTE Sens = 97% Spec = 21% 5

6 The PERC rule NPPV = 99% (PERC Neg + Low Suspicion) Criteria 1. no prior VTE 5. Age < 50 years 2. no hemoptysis 6. SaO2= > 95% 3. no estrogen use 7. pulse < 100 bpm 4. no hospitalization for 8. no unilateral leg swelling trauma/surgery w/in 4 wks More Recent Literature Hugli, JTH, 10 The PERC rule Retrospectively applied PERC to 1675 pts 96.6% Sensitive (but only 79% in low risk pts) 16% Specific Significant limits to retrospective application CASE #1 38 y.o. F, sudden onset, burning SSCP x 3 hrs Not pleuritic, positional, or radiating. No SOB No meds, Not a smoker, No other PMHx NAD, 120/80, 80, 18, 37.1, 96% Exam unremarkable ECG Normal CXR - Clear = PERC Negative 1. no prior VTE 5. Age < no hemoptysis 6. SaO2= > 95% 3. no estrogen use 7. pulse < no trauma/surgery 8. no unilateral leg w/in 4 wks swelling Rapid D-Dimer Tests TEST Sensitivity Specificity Latex Agglutination Qualitative 75% 99% Quantitative 95% 50% ELISA Microplate 95% 50% ELFA 97% 43% Whole Blood (SimpliRed) 87% 69% 6

7 D-Dimer Pearls Understand your Radiologic Tests! If you plan to perform a CT scan, order a d-dimer first you can potentially eliminate the need. Don t order the d-dimer if you wouldn t get a CT scan without it! Negative ELFA + 15% risk Patient => EXCLUDES PE (1.5% chance) Negative ELFA + 30% risk Patient => DOESN T EXCLUDE PE (3% chance) Optimize success CTPA - Pearls 18 or 20 g proximal IV delivers 100 to 150 ml dye at 4 ml/sec Minimize Complications Ask IV insertor re: risk of infiltration, esp. antecubital/ej s Check for h/o Allergy Consider Bicarb protocol in everyone 7

8 Radiation Doses Stein, Radiology, 2007 Background radiation = 3 msv/yr PA and Lat CXR = 0.07 msv CTPA = 2 to 8 msv Abd/pelvis CT = 10 msv Smith-Bindman, Arch IM 09 - Actual Doses!!!! CTPA 10 (7-14) msv CT abdomen 16 msv Understand results CTPA - Pearls Ask about quality of main PA opacification Good > 200 hounsefield units Understand Risks Radiation in the young Kidneys in the old Outpatient Treatment? Outpatient Treatment? ACCP guidelines 2008 No randomized trials of Rx in-hospital vs. at-home. Some trials of early discharge. Some observational studies of pts Rx d at home. EurSC guidelines 2008 Outpatient Rx is conceivable Hull et al. Arch IM 1997 CAREFUL! Risk of recurrent PE was 25 percent if PTT was sub-therapeutic in first 24 hours in pooled analysis of 3 trials Aujesky, Lancet, 2011 RCT of 344 Low Risk PE pts (PESI class 1/2) to inpt vs outpt (took 3.5 yrs) Rx d with BID enox - No difference in safety Excluded hypoxia, BP < 100, receipt of IV pain meds, obese, unreliable (ETOH, homeless) Average ED stay=12 hrs 8

9 Case #2 48 y.o. M with recent LE ORIF presents with leg swelling, acute SOB and pleuritic CP. No PMH of cardiopulmonary disease PEx: BP 90/60, HR 105, RR 20, Afeb, Sat=93% How would you manage this patient? Thrombolytics Answer: Confirm PE by either CTPA or right heart strain on bedside US Rx with TPA 100 mg IV over 2 hours + Heparin 5000u bolus and drip ACCP Guideline, CHEST 2008 Level 1 rec for Thrombolysis If hemodynamic compromise 1B If Right Heart Strain AND Low Risk Bleeding 2B IVC Filters Use when anticoagulation contraindicated Do Not Use in addition to anticoagulation Decousus, N Engl J Med pts with DVT Compared Filter + Warfarin vs Warfarin alone No difference in outcomes! Summary Consider PE in the patient with: Pleuritic CP Dyspnea Tachypnea Assign a risk Gestalt vs Clinical algorithm Use the PERC rule if Negative, excludes disease when pretest is < 10% 9

10 Send a sensitive d-dimer Summary Negative excludes dz in pt with < 10-15% pretest prob Probably too non-specific for inpatients Understand your CT Pulmonary Angiogram Summary Most patients require initial admission for at least 24 hours Thrombolyse your hypotensive PE patients 10