200 pearls and counting! Take the Pearls4Peers quiz #2!

Multiple choice (choose 1 answer)
1. Which of the following classes of antibiotics is associated with peripheral neuropathy?
a. Penicillins
b. Cephalosporins
c. Macrolides
d. Quinolones



2. The best time to test for inherited thrombophilia in a patient with acute deep venous thrombosis is…
a. At least 1 week after stopping anticoagulants and a minimum of 3 months of anticoagulation
b. Just before initiating anticoagulants
c. Once anticoagulation takes full effect
d. Any time, if suspected



3. All the following is true regarding brain MRI abnormalities following a seizure, except…
a. They are observed following status epilepticus only
b. They are often unilateral
c. They may occasionally be associated with leptomeningeal contrast enhancement
d. Abnormalities may persist for weeks or months



4. Which of the following is included in the quick SOFA criteria for sepsis?
a. Heart rate
b. Serum lactate
c. Temperature
d. Confusion



5. All of the following regarding iron replacement and infection is true, except…
a. Many common pathogens such as E.coli and Staphylococcus sp. depend on iron for their growth
b. Association of IV iron replacement and increased risk of infection has not been consistently demonstrated
c. A single randomized-controlled trial of IV iron in patients with active infection failed to show increased infectious complications or mortality with replacement
d. All of the above is true


True or false

1. Constipation may precede typical manifestations of Parkinson’s disease by 10 years or more
2. Urine Legionella antigen testing is >90% sensitive in legionnaire’s disease
3. Spontaneous coronary artery dissection should be particularly suspected in males over 50 years of age presenting with acute chest pain
4. Urine dipstick for detection of blood is >90% sensitive in identifying patients with rhabdomyolysis and CK >10,000 U/L
5. Diabetes is an independent risk factor for venous thrombophlebitis




Answer key
Multiple choice questions:1=d; 2=a;3=a;4=d;5=c
True or false questions:1=True; 2,3,4,5=False


200 pearls and counting! Take the Pearls4Peers quiz #2!

What is the utility of urine dipstick for blood in diagnosing rhabdomyolysis?

Although the dipstick method of detecting blood in the urine is convenient, it cannot differentiate between hemoglobin, myoglobin, or red blood cells. 1

Several reviews suggest that urine myoglobin is unstable with subpar performance in rhabdomyolysis1, often defined as creatine kinase (CK) elevation 5 times the upper limit of normal in the proper context (eg, crush injury, hypoxic/ischemic or drug injury). A sensitivity of 71% and a specificity of 54% for urine hemoglobin by dipstick, and a sensitivity of 25% and specificity of 75%  for urine myoglobin  has been reported in patients with serum CK >10,000 U/L. 3  

So while a positive dipstick for blood with few or no RBCs in the urine may make us think about rhabdomyolysis, its absence should not be used to exclude it in a susceptible host.

Final fun pearl: Did you know that consumption of quail has been associated with rhabdomyolysis, possibly due to their feeding on poisonous plants such as hemlock?


  1. Rodriguez-Capote Karina, Balion CM, Hill SA, et al. Utility of urine myoglobin for the prediction of acute renal failure in patients with suspected rhabdomyolysis: A systematic review. Clin Chem 2009;55:2190-97. https://www.ncbi.nlm.nih.gov/pubmed/19797717
  2. Nance JR, Mammen AL. Diagnostic evaluation of rhabdomyolysis. Muscle Nerve 2015;51:793-810. https://www.ncbi.nlm.nih.gov/pubmed/25678154
  3. Grover DS, Atta MG, Eustace JA, et al. Lack of clinical utility of urine myoglobin detection by microconcentrator ultrafiltration in the diagnosis of rhabdomyolysis. Nephrol Dial Transplant 2004;19:2634-38. https://www.ncbi.nlm.nih.gov/pubmed/15280520
What is the utility of urine dipstick for blood in diagnosing rhabdomyolysis?

Is there a connection between cirrhosis and elevated CK or rhabdomyolysis?

Besides the usual causes of rhabdomyolysis such as trauma, drugs, alcohol, sepsis, etc…, cirrhotic patients may also have what some have called “hepatic myopathy”.   One study involving 99 patients with cirrhosis and myopathy (all with elevated serum myoglobin) found “infections” as the most common cause (47%),  followed by “idiopathic” (27%) sources as well as ETOH, herbal medicine, and trauma-related causes (<10% each) (1).  Whether this is truly an entity  or just a non-causal association is unclear to me. The question now is whether we should lower our threshold in ordering CK in these patients.

1. Lee O-J, Yoon J-H, Lee E-J, et al. Acute myopathy associated with liver cirrhosis. World J Gastroenterol 2006;12:2254-2258.

Is there a connection between cirrhosis and elevated CK or rhabdomyolysis?