Quality of Care

An interesting paper examining the discussion of medical errors in morbidity and mortality conferences was published in JAMA.

It found that in GIM M+M conferences case presentations were longer than those in surgery M+M. Less time was spent on audience discussion, fewer case presentations included adverse events or errors causing adverse events. At surgery M+M, errors were more likely (P=.17) to be attributed solely to an individual rather than a team or system.

"That's Tight" - How to assess for Aortic Stenosis

We discussed EVAR (Endovascular Aneurysm Repair). A NEJM review can be found here. The precise role for EVAR (rather than open) repair is still debated. 2005 AHA guidleines suggest EVAR of infrarenal AAA could be considered in patients at high risk of complications following open repair and may be considered in those at low or average surgical risk. Longterm monitoring, including imaging, should be performed to ensure late complications do not develop. Several studies have been published since then and EVAR is being more widely used.

We also briefly discussed multiple myeloma. A review in BLOOD was published in 2008. Treatment in this field has evolved rapidly over recent years.

Finally, we discussed the physical exam diagnosis of aortic stenosis. The findings of a paper examining a clinical prediction rule for AS is summarized in the following figure from the article.


Abscence of a murmur over the right clavicle (see article Table 1 for how to auscultate for this) as performend by a staff internist or senior medical resident, effectively rules out moderate to severe AS (usually more important clinically than ruling in AS, as to rule it in a TTE will often be performed).

The JAMA rational clinical exam "Does this patient have an abnormal systolic murmur?" can be found here.

The Pneumonia formerly known as PCP

Pneumocysitis jirovecii pneumonia was previosuly named Pneumocystis carinii pneumonia. Some of the debate regarding the name change can be found here and in the associated references. Previously classified as a protozoa, but molecular studies have shown it to likely be a FUNGUS.

Generally occurs in HIV+ patients with a CD4 count below 200 cells/mm3. Can also occur in other immunosuppressed hosts.

PRESENTATION
Subacute onset of (exertional) dyspnea, dry cough +/- "low-grade" fever.
Physical Exam shows tachypnea, tachycardia and normal lung auscultation in 50% (the remainder having crackles etc.).
CXR - classically bilateral, perihilar interstitial infiltrates, but can show almost anything (or nothing). However, pleural effusions and/or lymphadenopathy is very rare.

DIAGNOSIS
In addition to the clinical presentation, microscopic examination of (induced) sputum, BAL fluid or tissue can be performed. PJP cannot be readily cultured (be sure to specify you want sputum tested for PJP if it is in your Ddx), it can be seen with methenamine silver or immunofluorescence stains.

Laboratory data is generally not very informative. LDH is elevated in 90%, but this is very non-specific.

TREATMENT
TMP-SMX - high dose (see reference) x 21 days. Alternatives included inhaled pentamidine and atovaquone. Remember to start prophylaxis after finishing treatment!

Patients with PCP may worsen after two to three days of therapy, possibly from inflammation in response to dying organisms.

Corticosteroids are of benefit in patients who are hypoxic at presentation (PaO2 on room air less than 70mmhg or oxygen saturation <90%)

The benefit of steroids in PCP was shown in a study conducted in Toronto in 1987.

A NEJM review article can be found here

Thanks to prior CMRs for some of the above.



As discussed at noon rounds: Nystatin was isolated from Streptomyces noursei by Elizabeth Lee Hazen and Rachel Fuller Brown. The soil sample where they discovered nystatin was from the garden of Hazen's friends, Walter B. Nourses, therefore the strain was called noursei. It contained a substance that they first named fungicidin, a name that had already been used for another substance. They then renamed the substance nystatin in honor of the New York State Public Health Department, where they worked.

What's the diff?

CLOSTRIDIUM DIFFICILE

Gram positive anaerobic bacillus - cytotoxin producing. Disease caused when toxin(s) bind to the surface of intestinal epithelial cells, where they are internalized and catalyze the glucosylation of cytoplasmic rho proteins, leading to cell death.

Typical occurs in elderly/instiutionalized especially after receiving antibioitics. Historically Clindamycin has been associated with high risk of C diff, in the Quebec outbreak in 2003, fluoroquinolone use was also associated with the development of infection. Direct person-to person spread occurs and previously healthy/younger/non institutionalized patients have also been infected.

PREVENTION

need responsible antibiotic use
infection-control measures (contact precautions, hand hygiene, environmental decontamination)

DIAGNOSIS
Microbiology

• C. diff toxin assay (EIA) detects toxins A and B and has ~70% sensitivity, with ~90-95% sensitivity on three tests. The specificity is> 95%.
• The most sensitive assay is the test for cytopathic effect, which is not available here
• You can also culture Clostridium difficile from the stool, but this is not routinely done, as there are nonpathogenic strains
  
• A positive toxin assay in a patient with minimal or no symptomsshould not prompt treatment. (i.e. only send for toxin testing if there is sufficient pre-test probability)

Radiology

• Consider AXR to assess for toxic megacolon -a maximum colonic diameter greater than 6 cm is consistent with megacolon, may also see bowel wall changes
  
• CT scan helpful for further assessment and to R/O other causes of colonic distension etc.. May show thickening of the bowel wall, colitis, ileus
  

Sigmoid/Colonoscopy
Generally avoided with typical presentation and positive toxin EIA

Concern regarding endoscopy/insuflation of air causing perforation, especially if toxic megacolon present

May see pseudomembranes diagnostic of pseudomembranous colitis
Consider endoscopy if:

• Atypical presentation (ileus etc.)
• Other diagnoses suspected/need to be ruled out
• Failure of C. difficile infection to respond to therapy
  

TREATMENT

See table from NEJM review here.

First Episode
***If possible stop offending antibiotics***

• Mild/Moderate Disease
  
  • Metronidazole OR Vancomycin (PO) duration 10-14d
    
• Severe Disease
  
  • Defined as:
    
    • Two of (Age above 60, Febrile, WBC above 15, Albumin below 25)
      
    • OR hypotension/shock or Cr greater than 1.5x normal, or toxic megacolon, peritoneal signs, perforated bowel
      
  • Infectious Disease +/- General Surgery Consultation
  • ICU Consult for patients with hemodynamic comprimise
    
  • Vancomycin (PO) unless severe illeus/toxic megacolon, then Metronidazole (IV) duration 10-14d (Vanco has more rapid symptom resolution and a lower risk of treatment failure).

Relapse

• First relapse --> can repeat last treatment depending on severity
• Second relapse --> vancomycin taper. ID consult.

NEJM Review article (2008) can be found here.
A paper discussing Vanco as first line treatment can be found here.
Thanks to Dr. T.C Lee for some of the above post.

Gallstone Ileus

Occurs after gallstone lodges in bowel (generally terminal ileum - the narrowest intestinal area). The stone gets into the gut through a biliary enteric fistula.

Average age of affected patients is 70 years, more common in women.

In a large surgical series of patients undergoing cholecystectomy described here:

1.8% had a cholecystoenteric fistula
90% of patients with a cholecystoenteric fistula had Mirrizi syndrome (common hepatic duct obstruction caused by extrinsic compression from an impacted stone in the cystic duct)
5.7% of patients had Mirrizi syndrome

PRESENTATION
Classically a subacute obstruction in an elderly female that occurs episodically as the stone passes through and transiently obstructs the GI tract. (Transient) abdo pain, vomitting, abdo distension, increased bowel sounds

Bouveret's syndrome - gastric outlet obstruction secondary to an impacted gallstone in the duodenum or pylorus

Less than 15% of gallstones can be seen on plain film. Other AXR findings - parital or total SBO, pneumobilia. CT scan is likely better to visualize the stone/obstruction and MRCP may be best to define biliary anatomy

TREATMENT
Supportive until definitive treatment.

Surgical - enterolithotmy (with care to examine for >1 stone) +/- concurrent cholecystectomy or delayed laparoscopic cholecystectomy

Alternatives - extracorporeal lithotripsy, endoscopy (not first line)

"When you're sliding into first...."

BLOODY DIARRHEA

A good discussion on the differential diagnosis of bloody and none bloody diarrhea of acute onset occurred today.

As always, a good history (as always) goes a long way in helping to focus the picture. In addition to a travel/sick contacts/dietary/medication history, sexual history is also important.

It is recommended that all patients with acute bloody diarrhea (including on history and FOB +) undergo stool culture.

DIFFERENTIAL DIAGNOSIS
Infection:
cytoxic - E. coli (EHEC) O157:H7 (often present with no fever), C. Difficile
invasive - E. coli (EIEC), Salmonella, Shigella, Yersinia, Campylobacter
Inflammatory: Inflammatory Bowel disease, radiation proctitis/colitis
Ischemic Colitis

Non diarrheal causes of Lower GI bleed should also be considered (diverticular disease, etc.)
Other considerations are rarer and depend on immunosuppression (CMV colitis) and exposure (GI anthrax, Intestinal TB, intestinal amebiasis, HSV procitis etc.)

A study of infectious etiologies (determined by stool culture) of acute bloody diarrhea in patients presenting to the ER in the US is posted here. If found enteropathogens in 12.5% of cases that were cultured despite the physician's presumptive diagnosis of a noninfectious cause.

A second study of the clinical and epi factors of diarrhea in the U.S. is posted here.

For an excellent blog on Infectious Disease issues see: http://www.idologist.com/Blog/

NASH

Non Alcoholic SteatoHepatitis

CAUSES:
Metabolic Syndrome - obesity, diabetes, hyperlipidemia

Metabolic - hypothyroidism, TPN, rapid weight loss

GI surgery - gastroplasty, jejunal bypass, small bowel resection

Drugs - Tamoxifen, amiodarone, prednisone, estrogens

TREATMENT: Modify risk factors. Weight loss should be gradual as rapid weight loss can worsen the liver injury. Identify and treat underlying causes (hypothyroid, meds, etc.). Preliminary studies have shown that metformin or pioglitazone may one day have a role in treatment, but their exact longterm benefit is not clear.

Click here for a 2002 NEJM Review article.

Cholesterol Emboli

Cholesterol Emboli Syndrome was discussed in the context of acute renal failure and raised lots of interesting issues.

ACUTE RENAL FAILURE:
A standard approach

Prerenal: Volume depletion, hemorrhage, decreased effective circulating volume (CHF, cirrhosis), renal artery stenosis

Renal: Glomerular - Glomerulonephritis (and its associated long list of causes), Acute interstitial nephritis, Acute tubular necrosis (either ischemic or nephrotoxic), Vascular

Postrenal: Obstruction of collecting system or extrarenal drainage

PERIPHERAL EOSINOPHILA
While discussing laboratory findings of AIN, the differential diagnosis of a peripheral eosinophilia was reviewed:
Allergic - rhinitis, asthma, meds.
Infectious - parasitic (helminths), fungal, other
Hematologic - Hypereosinophilia Syndrome, leukemia, lymphoma
Specific Organ Involvement - blood eosinophilia can occur when tissue eosinophilic infiltration is present in pulmonary, GI, derm, cardiac, rheumatologic or renal disease

CHOLESTEROL EMBOLI SYNDROME
Occurs in people with atherosclerotic disease
Spontaneous or as a result of intravascular procedure
Result of cholesterol crystal embolism causing occlusion of multiple small arteries leading to further inflammation and intimal proliferation

Pathology - "ghosts" of cholesterol crystals as they are dissolved during fixation

Symptoms:
Non specific H/A, myalgia, fever
Derm -livedo reticularis (lacy rash), ulceration, gangrene, "blue toe syndrome"
Acute Renal Failure -

GI - intestinal ischemia
Eyes - Hollenhorst plaques (cholesterol crystals in retinal arteries)

Labwork - nonspecific: elevated WBC/ESR, hypocomplementemia, Cr and urine eosinophils (if renal involvement), eosinophila

In the abscence of other symptoms consistent with cholesterol emboli, post angiogram renal failure will often be diagnosed as contrast nephropathy. Ways to try to distinguish the two:

• Presence of other signs of cholesterol emboli (obviously)
• Transient eosinophilia/hypocomplementemia
  
• Persistent renal failure (much less common in contrast nephropathy)

Links to a prosepctive study on CES risk factors and incidence can be found here and the associated editorial here. They found elevated baseline CRP to be an independent risk factor for CES after cardiac cath. Thanks to the facilitator for these.

See a picture of Hollenhorst plaque (from UMich) below:

"Poncho Sign" and Heliotrope Rash

DERMATOMYOSITIS

Dermatomyositis and polymyositis = inflammatory myopathies that are often discussed together because they often present as symmetric proximal muscle weakness.

Dermatomyositis, however, is associated with skin findings and is much more likely to be associated with an underlying malignancy.

SKIN FINDINGS - Heliotrope rash (see picture),Gottron's papules, periungual changes, "mechanic's hands", and the shawl sign - which some MDs felt appeared more like a poncho sign in certain patients.

Lung Involvement - ILD, respiratory muscle weakness

GI Involvement - Dysphagia, regurgitation, aspiration

Cardiac Involvement - Myocarditis, pericarditis, arrhythmias

SEROLOGY - ANA+ in 80%. Ongoing research into myositis specific antibodies (currently felt to be present in 30%) to help determine likely clinical progression and treatment response

MALIGNANCY - Incidence of cancer is 5-7x higher than general pop'n. Peak incidence of diagnosis is within 2 years before or after the DM diagnosis. Search guided by complete history and physical. Bloodwork, imaging and tumor markers (CA125, CA 19-9, PSA) and age appropriate cancer screening.

Ongoing cancer surveillance suggested for 3-4 years after diagnosis or recurrence, with the exception of ovarian CA which can occur >5 years after diagnosis (therefore screen for longer).

Publications on malignancy frequency in DM/PM can be found here (don't forget they have a higher baseline incidence of nasopharyngeal CA in China - it isn't the most common DM associated cancer here) and here.

THERAPY- Treat the cancer!! (If you can find it without going overboard looking!)

Involves steroids at relatively high doese for prolonged periods of time. Steroid sparing agents such as azathipone and methotrexate are also used. Guided by clinical exam/weakness rather than CK/other markers.

As steroid course will be prolonged, be sure to consider the associated side effects and posible infections including TB.

Patients with polymyositis/dermatomyositis who have interstitial pulmonary fibrosis may be at increased risk for PCP with glucocorticoids alone compared to other populations.

A review of treatment can be found here.

Atrial Fibrillation

Acute management of atrial fibrillation:


First question - STABLE vs UNSTABLE?
(Instability rare if HR<150)>

Unstable if - hypotension, chest pain, altered mental status, other signs of shock

If Unstable - requires immediate synchronized cardioversion (with appropriate sedation, monitoring, etc).

If stable - consider rate control (oral or IV) with agents such as beta blockers, calcium channel blockers (Non-dihydropyridines) and amiodarone - depending on the clinical situation/contraindications.

The ACLS Tachycardia algorithim can be found here.

ANTICOUAGULATION in chronic/paroxysmal AFIB:
Initiated to prevent embolic stroke.
Risk similar in chronic vs paroxysmal AFib

CHADS2 score - used to risk stratify patients
C-Congestive Heart Failure (1point)
H-Hypertension (1point)
A-Age>75 (1point)
D-DM (1 point)
Stroke/TIA - (2 points)

CHADS2 score of 0 associated with 0.5%/year chance of stroke without coumadin
CHADS2 score >=3 associated with >5.3%/year chance of stroke without coumadin]
Patients with higher stroke risk will have greater benefit with anticoagualtion.

See the original article here.

Informed discussions should take place with patients to determine the risk/benefit of starting on anticoagulation with coumadin (target INR 2-3).

MDs are often concerned about starting anticoagulation in patients who fall. A decision analysis conducted in part by a Toronto based researcher suggested that patients with an average risk of stroke from AFib would have to fall 300 times in one year for the risk of anitcoagulation to outweigh its benefit - see article here.