My hospitalized patient with sepsis has persistently elevated lactic acid despite volume resuscitation, source control, and adequate oxygenation. What could I be missing?

Although the causes of lactic acidosis are legion (eg, sepsis, tissue hypoperfusion, ischemic bowel, malignancy, medications, liver dysfunction), thiamine deficiency (TD) is an often-overlooked cause of persistently elevated serum lactic acid (LA) in critically ill hospitalized patients,1 reported in 20-70% of septic patients.2  Septic shock patients may be particularly at risk of TD because of increased mitochondrial oxidative stress, decreased nutritional intake and presence of comorbid conditions (eg,  alcoholism, persistent vomiting).3

Early recognition of TD in hospitalized patients may be particularly difficult because of the frequent absence of the “classic” signs and symptoms of Wernicke’s encephalopathy (eg, ataxia, cranial nerve palsies and confusion) and lack of readily available confirmatory laboratory tests.4

TD-related lactic acidosis should be suspected when an elevated LA persists despite adequate treatment of its putative cause(s) (4,5). Administration of IV thiamine in this setting may result in rapid clearance of LA.3-5

TD causes lactic acidosis type B which is due to the generation of excess LA, not impairment in tissue oxygenation, as is the case for lactic acidosis type A. Thiamine is an essential co-factor in aerobic metabolism, facilitating the conversion of pyruvate to acetyl-CoA which enters the citric acid (Krebs) cycle within the mitochondria. In TD, pyruvate does not undergo aerobic metabolism and is converted to LA instead, leading to lactic acidosis.

Bonus pearl: Did you know that because of its limited tissue storage, thiamine stores may be depleted within only 3 weeks of reduced oral intake!


  1. O’Donnell K. Lactic acidosis: a lesser known side effect of thiamine deficiency. Practical Gastroenterol March 2017:24.
  2. Marik PE. Thiamine: an essential component of the metabolic resuscitation protocol. Crit Care Med 2018;46:1869-70.
  3. Woolum JA, Abner EL, Kelly A, et al. Effect of thiamine administration on lactate clearance and mortality in patients with septic shock. Crit Care Med 2018;46:1747-52.
  4. Kourouni I, Pirrotta S, Mathew J, et al. Thiamine: an underutilized agent in refractory lactic acidosis. Chest 2016; 150:247A.
  5. Shah S, Wald E. Type B lactic acidosis secondary to thiamine deficiency in a child with malignancy. Pediatrics 2015; 135:e221-e224.

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My hospitalized patient with sepsis has persistently elevated lactic acid despite volume resuscitation, source control, and adequate oxygenation. What could I be missing?

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!

Should male patients with suspected urinary tract infection routinely undergo a prostate exam?

Yes! That’s because any urinary tract infection (UTI) in men has the potential for prostatic involvement1 —-as high as 83% by one report. 2  

To make the matters more confusing, patients with acute bacterial prostatitis (ABP) often present with symptoms just like those of UTI,  such as urinary frequency, dysuria, malaise, fever, and myalgias. 3  In the elderly, atypical presentation is not uncommon (eg, confusion, incontinence, fall). 4  Under these circumstances, bacteriuria and pyuria may also be related to ABP and the prostate exam should be an important part of your evaluation.

Although the sensitivity of prostate tenderness on digital rectal exam varies widely for ABP (9%-100%), a painful exam should raise suspicion for ABP, and by itself may be an independent predictor for clinical and bacteriologic failure of therapy. 1 Along with tenderness, fluctuance of prostate, particularly in the setting of voiding difficulties and longer duration of symptoms, may also suggest the presence of prostatic abscess. 5,6 

But be gentle when performing a prostate exam and don’t massage it because you could potentially cause bacteremia and worsening of sepsis! 1,7

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  1. Etienne M, Chavanet P, Sibert L, et al. Acute bacterial prostatitis: heterogeneity in diagnostic criteria and management. Retrospective multicentric analysis of 371 patients diagnosed with acute prostatitis. BMC Infectious Diseases 2008;8:12.
  2. Ulleryd P, Zackrisson B, Aus G, et al. Prostatic involvement in men with febrile urinary tract infection as measured by serum prostate-specific antigen and transrectal ultrasonography. BJU Int 1999;84:470-4.
  3. Krieger JN, Nyberg L, Nickel JC. NIH consensus definition and classification. JAMA 1999;282:236-37.
  4. Harper M, Fowlis. Management of urinary tract infections in men. Trends in Urology Gynaecology & Sexual Health. January/February 2007.
  5. Lee DS, Choe HS, Kim HY, et al. Acute bacterial prostatitis and abscess formation. BMC Urology 2016;16:38.
  6. Oliveira P, Andrade JA, Porto HC, et al. Diagnosis and treatment of prostatic abscess. International Braz J Urol 2003;29: 30-34.
  7. Lipsky BA, Byren I, Hoey CT. Treatment of bacterial prostatitis. Clin Infect Dis 2010; 50:1641-52.


Should male patients with suspected urinary tract infection routinely undergo a prostate exam?