Tag Archives: pulm

Quick Hit: D-Dimer false positives

30 Jun

Thinking about ordering a D-Dimer for PE rule-out? What are the clinical conditions to consider thatmay make your D-Dimer falsely elevated?

  • Myocardial infarction
  • Stroke
  • Atrial fibrillation
  • Preeclampsia and eclampsia
  • Cardiovascular disease
  • Congestive heart failure
  • Severe infection
  • Surgery/trauma
  • Sickle cell disease
  • Severe liver disease (decreased clearance)
  • Malignancy
  • Renal disease
  • Pregnancy


Source: uptodate.com; picture


Submitted by K Estes.


pertussis: quick hits

17 Feb

(Should’ve been posted earlier, but didn’t make it up somehow.  Here it is now, though, for your learning pleasure).

Pertussis is bad and increasing – it kills ~300,000/yr in non-vaccinated places & can cause serious systemic issues like vert dissection, etc.

– B. pertussis starts like a viral URI (cough, rhinorrhea, malaise)

incubation period is about a week or so, and it is very contagious by air particles (use precautions!)

– more common in older adults who have waning immunity.

– The danger is for passing it to infants who have not immunity.

– In older adults, it is persistent cough lasting ~3-4 weeks and getting worse from week 1 to 2. Often paroxysmal.

– In infants, it is flu-like symptoms followed by paroxysmal cough with whooping inspiration against a closed glottis.

– Protect against pertussis with DTaP or Tdap.

– Test for pertussis with PCR (earlier) or culture (later)

– Treat pertussis early if possible, use Azithromycin

– Treat in those with high suspicion, those exposed, and those with suspicion with infants at home.


Submitted by J. Stone.


Sources: uptodate.com;  EMRap podcast discussion; picture

quick reference: what counts as Health-care Associated Pneumonia?

6 Feb


  • antibiotics within 90 days
  • current hospitalization >= 5 days
  • high frequency of antibiotic resistance in the community/hospital unit
  • presence of risk factors for HCAP
    • hospitalization >=2 days within 90 days
    • nursing home/extended care facility resident
    • home infusion therapy (incl. antibiotics)
    • chronic dialysis within 30 days
    • home wound care
    • family member with multi-drug resistant pathogen
  • immunosuppressive disease/therapy

This came up recently on a search to see if health care workers would be considered at risk for HCAP (technically, it appears ‘no’), though a brief search did not find much in the way of definitive statements. Anecdotally, practice patterns seem to differ.   Any discoveries/opinions appreciated in the comments section!


References: medscape 1, 2; thoracic.org; picture


word of the day: pneumorrhachis!

2 Dec

from a recent JEM article by Aiyappan et al.  

Case report of a 53 yo M complaining of facial and chest puffiness.  Had a hx of asthma.  X-ray/CT showed mediastinal air and subcutaneous emphysema, and also….



= intraspinal air

-> rare, can extend from posterior mediastinum into the dural space through the neural foramen.

-> can be asymptomatic, but watch out for cord compression symptoms


For some more depth, check out this 2006 review of this rare phenomenon.


References: case report, 2006 review; picture


Treatment of Primary Spontaneous Pneumothoraces

12 Aug


Primary= No apparent lung disease   vs   Secondary= Underlying lung disease

 –Spontaneous= No precipitating event (no traumatic/iatrogenic cause)

-The definition of a “small” pneumothorax can vary. For the most part, this means the distance between the lung and chest wall on CXR is <3cm. 


3 Senarios:

  1. Stable patient, small pneumothorax

-Give supplemental O2

-Observe in the ED 3-6 hours

-Repeat x-ray. If no progression and patient is asymptomatic, discharge with follow up in 12 hrs- 2 days.     Otherwise admit.

  1. Stable patient, large pneumothorax

                -Small-bore catheter (<14F/pigtail)    OR    16-22F chest tube and admit

Note: Some physicians have discharged patients with a chest tube in place and a Heimlich valve with follow up in 1-2 days if the patients refuse hospitalization but are reliable. This makes me nervous.


                -Needle aspiration

-There is pretty good data (multiple recent articles) behind needle aspiration of pneumothoraces instead of placing a chest tube. This is the recommended treatment in England but this is not in the American College of Chest Physicians guidelines.  A 2008 Annals review shows no difference in rate of failure/recurrence but lower rates of hospitalization, length of stay, comfort.  HRD has a prior blog post about this.

-You can watch a video of this procedure on the NEJM site under the article: Pasquier et al. “Needle Aspiration of Primary Spontaneous Pneumothoraces” NEJM 2013; 368:e24

  1. Unstable patient

                -Large chest tube.  Could use 16F-22F chest tube but will likely use 24F-28F chest tube as PPV is likely required.


Submitted by Heather Groth.


Baumann et al. “Management of Spontaneous Pneumothorax: An American College of Chest Physicians Delphi           Consensus Statement” Chest. 2001;119(2):590-602.

Bintcliffe et al. “Spontaneous Pneumothorax” BMJ 2014; 348:g2928

Pasquier et al. “Needle Aspiration of Primary Spontaneous Pneumothoraces” NEJM 2013; 368:e24


Up to Date

Zehtabchi S, Rios C L. Management of emergency department patients with primary spontaneous pneumothorax: needle aspiration or tube thoracostomy? Annals of Emergency Medicine 2008; 51(1): 91-100.



CURB-65: pneumonia score refresher

19 May

broken down for easy reference:


1 point each:

  • Confusion
  • Uremia (BUN > 19 mg/dL)
  • Respiratory rate > 30
  • Blood pressure < 90 (systolic) or <=60 (diastolic)
  • 65 (age >= 65)


estimated 30-day mortality

  • 0 points: 0.6%
  • 1 point: 2.7%
  • 2 points: 6.8%
  • 3 points: 14%
  • 4-5 points: 27.8%



  • 0-1 point – consider outpatient treatment
  • 2 points – consider inpatient tx, or outpatient tx + close follow-up
  • 3 points – inpatient tx, +/- ICU
  • 4-5 points – ICU



CURB-65 > 2:

  • sensitivity 0.62
  • specificity 0.79


References: review, MDCalc, utilitypicture



carbon monoxide testing

13 May


Your next patient is a 30 yo who is brought in by EMS after being pulled out of a burning apartment building.  They’re awake, but complaining of a headache, and of course, you’re worried about carbon monoxide. 

How do you want to test for this, and what number/percent are you ok with?



2 most commonly found options in the ED: co-oximetry & serum carboxyhemoglobin testing


noninvasive pulse co-oximetry (similar to your pulse-ox, but for CO)

  • via some small studies: mean absolute error of 3.15% (vs. serum testing)
  • frame of reference: mean absolute variation between various blood gas analyzers – 2.4%


carboxyhemoglobin testing

  • relationship between COHb levels and poisoning severity is generally poor
  • no clinically relevant difference between arterial and venous COHb levels
    • 95% of samples range between 2.4% and -2.1% of each other
  • COHb level > 3% in non-smokers or > 10% in smokers suggests an abnormal CO exposure


References: EBMedicine article, picture