Infection;

My elderly nursing home patient is admitted with recent poor oral intake, falls and oral temperatures of 99.1°-99.3° F(37.3°-37.4°C). Is she considered febrile at these temperatures?

FA Manian MD, MPH, , , , , , Leave a comment

Yes! Even though we often think of temperatures of 100.4°F (38° C) or greater as fever, older people often fail to mount an appropriate febrile response despite having a serious infection. 1

Infectious Diseases Society of America (IDSA) guideline on evaluation of fever in older adult residents of long-term care facilities has defined fever in this population as:2

  • Single oral temperature >100° F (>37.8° C) OR
  • Repeated oral temperatures >99° F (>37.2° C) OR
  • Rectal temperatures >99.5° F (>37.5° C) OR
  • Increase in temperature of >2° F (>1.1° C) over the baseline temperature

Even at these lower than traditional thresholds for defining fever, remember that many infected elderly patients may still lack fever. In a study involving bacteremic patients, nearly 40% of those 80 years of age or older did not have fever (defined as maximum temperature over 24 hrs 100° F [37.8°C] or greater).3  

So our patient meets the criteria for fever as suggested by IDSA guidelines and, particularly in light of her recent poor intake and falls, may need evaluation for a systemic source of infection.

Bonus Pearl: Did you know that blunted febrile response of the aged to infections may be related to the inability of cytokines (eg, IL-1) to reach the central nervous system?1

Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

References 

  1. Norman DC. Fever in the elderly. Clin Infect Dis 2000;31:148-51. https://academic.oup.com/cid/article/31/1/148/318030
  2. High KP, Bradley SF, Gravenstein S, et al. Clinical practice guidelines for the evaluation of fever and infection in older adult residents of long-term care facilities: 2008 update by the Infectious Disease Society of America. Clin Infect Dis 2009;48:149-71. http://www.idsociety.org/uploadedFiles/IDSA/Guidelines-Patient_Care/PDF_Library/Fever%20and%20Long%20Term%20Care.pdf
  3. Manian FA. Fever, abnormal white blood cell count, neutrophilia, and elevated serum C-reactive protein in adult hospitalized patients with bacteremia. South Med J 2012;105;474-78. http://europepmc.org/abstract/med/22948327

 

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis or its affiliate healthcare centers, Mass General Hospital, Harvard Medical School or its affiliated institutions. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

My elderly nursing home patient is admitted with recent poor oral intake, falls and oral temperatures of 99.1°-99.3° F(37.3°-37.4°C). Is she considered febrile at these temperatures?

Is iron therapy contraindicated in my patient with active infection?

FA Manian MD, MPH, , , , , , 1 Comment

In the absence of randomized-controlled trials of iron therapy in patients with active infection, the harmful effects of iron therapy (IT) in this setting remains more theoretical than proven. 1,2

Although many pathogens (eg, E. coli, Klebsiella, Salmonella, Yersinia, and Staphylococcus species) depend on iron for their growth2,3, and iron overload states (eg, hemochromatosis) predispose to a variety of infections, studies evaluating the risk of infection with iron therapy have reported conflicting results.1-4 A 2015 systematic review and meta-analysis of 103 trials comparing IV iron therapy  with several other approaches, including oral iron therapy or placebo, found no increased risk of infections with IV iron.5 In contrast, an earlier systematic review and meta-analysis involving fewer number of trials found an increased risk of infections with IV iron. 6

These varied results are perhaps not surprising since the effects of iron therapy on the risk of infection is likely to be context-specific, depending on the patient’s preexisting iron status, exposure to potential infections and co-infection and genetic background. 4 Of interest, mice with sepsis have worse outcomes when treated with IV iron.7

Perhaps the most prudent approach is to hold off on iron therapy until the active infection is controlled, unless the benefits of urgent iron therapy is thought to outweigh its theoretical harmful effects.

 

Liked this post? Sign up under MENU and catch future pearls in your inbox!

 

References

  1. Daoud E, Nakhla E, Sharma R. Is iron therapy for anemia harmful in the setting of infection? Clev Clin J Med 2011;78:168-70. http://www.mdedge.com/ccjm/article/95480/hematology/iron-therapy-anemia-harmful-setting-infection
  2. Hain D, Braun M. IV iron: to give or to hold in the presence of infection in adults undergoing hemodialysis. Nephrology Nursing Journal 2015;42:279-83. https://www.ncbi.nlm.nih.gov/pubmed/26207288
  3. Jonker FAM, van Hensbroek MB. Anaemia, iron deficiency and susceptibility of infections. J Infect 204;69:523-27. https://www.ncbi.nlm.nih.gov/pubmed/28397964
  4. Drakesmith H, Prentice AM. Hepcidin and the iron-infection axis. Science 2012;338:768-72. https://www.ncbi.nlm.nih.gov/pubmed/23139325  
  5. Avni T, Bieber A, Grossman A, et al. The safety of intravenous iron preparations: systematic review and meta-analysis. Mayo Clin Proc 2015;90:12-23. http://www.mayoclinicproceedings.org/article/S0025-6196(14)00883-0/pdf
  6. Litton E, Xiao J, Ho KM. Safety and efficacy of intravenous iron therapy in reducing requirement for allogeneic blood transfusion: systematic review and meta-analysis of randomized clinical trials. BMJ 2013;347:f4822. https://www.ncbi.nlm.nih.gov/pubmed/23950195
  7. Javadi P, Buchman TG, Stromberg PE, et al. High dose exogenous iron following cecal ligation and puncture increases mortality rate in mice and is associated with an increase in gut epithelial and splenic apoptosis. Crit Care Med 2004;32:1178-1185. https://www.ncbi.nlm.nih.gov/pubmed/15190970
Is iron therapy contraindicated in my patient with active infection?

How exactly do urinary tract infections (UTIs) cause delirium in my elderly patients?

FA Manian MD, MPH, , , , , , , , Leave a comment

 UTIs are often considered in the differential diagnosis of causes of delirium in the elderly. Though largely speculative, 2 possible pathophysiologic basis for this association are suggested:1-3

  •  Direct brain insult (eg, in the setting of sepsis/hypotension)
  • Indirect aberrant stress response, involving cytokines/inflammatory pathways,  hypothalamic-pituitary-adrenal [HPA] axis and sympathetic nervous system (SNS). One or both pathways can interact with the neurotransmitter and intracellular signal transduction systems underlying delirium in the brain, which may already be impaired in the elderly due to age-related or other pathologic changes.

The indirect aberrant stress pathway suggests that not only pain and discomfort (eg from dysuria) can contribute to delirium but UTI-associated circulating cytokines may also cause delirium.  Indeed, a large study of older adults undergoing elective surgery found a significant association between delirium postoperatively (postop day 2) and serum proinflammatory cytokine levels such as IL-6. 4  

The corollary is that bacteriuria is unlikely to be associated with delirium in the absence of significant systemic inflammatory response, pain or discomfort. We just need to do proper studies to prove it!

Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

References

1.Trzepacz P, van der Mast R. The neuropathophysiology of delirium. In Lindesay J,  Rockwood K, Macdonald A (Eds.). Delirium in old age, pp. 51–90. Oxford University Press, Oxford , 2002.

2.Flacker JM, Lipsitz LA. Neural mechanisms of delirium: current hypotheses and evolving concepts. J Gerontol A Biol Sci Med Sci. 1999; 54: B239–B246 https://www.ncbi.nlm.nih.gov/pubmed/10411009

3. Maclullich AM, Ferguson KJ, Miller T, de Rooij SE, Cunningham C. Unravelling the pathophysiology of delirium: a focus on the role of aberrant stress responses. J Psychosom Res. 2008;65:229–38. https://www.ncbi.nlm.nih.gov/pubmed/18707945

4. Vasunilashom SM, Ngo L, Inouye SK, et al. Cytokines and postoperative delirium in older patients undergoing major elective surgery. J Gerontol A Biol Sci Med Sci 2015;70:1289-95. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4817082/pdf/glv083.pdf

Contributed by Henrietta Afari MD, Mass General Hospital, Boston, MA

How exactly do urinary tract infections (UTIs) cause delirium in my elderly patients?

What are the major changes in the definition of “sepsis” under the 3rd International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3)?

FA Manian MD, MPH, , , , , , , , Leave a comment

Under Sepsis-3 [1], sepsis is defined as a “life-threatening organ dysfunction caused by a dysregulated host response to infection (suspected or confirmed)”. Systemic inflammatory response syndrome (SIRS) is no longer defined as part of the sepsis spectrum, and its criteria have been replaced by the Sequential Organ Failure Assessment (SOFA) with a change in score ≥2 (Table) having >10% in-hospital mortality. Septic shock is defined as hypotension requiring vasopressors to maintain a MAP ≥65 mm Hg and a lactate >2 mmol/L (18 mg/dL) despite adequate volume (>40% in-hospital mortality).

A bedside clinical tool “quickSOFA” (qSOFA), not meant to substitute for SOFA, is also proposed to identify patients primarily outside of the ICU who may be at high risk of adverse outcomes, based on the following criteria: systolic blood pressure ≤100 mmHg, respiratory rate ≥22/min, and altered mental status. A qSOFA score ≥2 is associated with poorer outcomes [1,2].

So what do these new guidelines mean for clinicians? Under the new terminology, “sepsis” now refers only to what was previously considered severe sepsis with or without shock, and those who may need more aggressive therapy, closer monitoring and possible transfer to an ICU [1,2]. As the guidelines stress, however, failure to meet qSOFA or SOFA criteria should by no means lead to a deferral or delay in evaluation or treatment of infection deemed necessary by clinicians, and SIRS criteria may still be useful in identification of infection [1].

It remains to be seen whether limiting the definition of sepsis to only patients with associated organ dysfunction will translate into an overall earlier diagnosis and improved prognosis for this condition.

Using SIRS criteria (ie, 2 or more of the following, heart rate >90/min, respiratory rate >20/min  or PaC02 <32 mm Hg, temperature<36 C or >38 C, WBC <4,000 or >12,000 or bandemia >10%) in patients suspected of having a potentially serious infection still makes sense if the goal is to identify it “upstream” before organ dysfunction or shock sets in.  Stay tuned!

 

Table. Sequential (sepsis-related) organ failure assessment (SOFA) score (adapted from ref.1)____________________________________________________________________________________________________

                                                                                             Points

Parameter                                0                      1                      2                      3                      4

____________________________________________________________________________________________________

Pa02/Fi02                           ≥400                 <400                <300                 <200*          <100*

Platelets (no./mL)           >150,000         <150,000         <100,000         <50,000       <20,000

Bilirubin (mg/dL)            <1.2                  1.2-1.9              2.0-5.9             6.0-11.9       >12.0

MAP (mm Hg) or VP      MAP≥70         MAP<70          DPA≤5           DPA 5.1-15        DPA>15

Glascow Coma Scale       15                    13-14            10-12                    6-9                 3-6

Creatinine (mg/dL)        <1.2                 1.2-1.9           2.0-3.4                  3.5-4.9        >5.0

OR U.O.  (mL/dL)                                                                                              <500                <200

____________________________________________________________________________________________________

MAP= mean arterial pressure, VP=vasopressor (includes agents other than dopamine), DPA=dopamine (in mcg/kg/min for ≥1 hour);U.O.= urine output

*With respiratory support

 

If you liked this post, sign up under MENU and catch future pearls straight into your mailbox!

References:

  1. Singer MS, Deutschman CS, Seymour CW, et al; The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016;315[8]:801-810. https://jamanetwork.com/journals/jama/fullarticle/2492881  
  2. Jacob JA. New Sepsis Diagnostic Guidelines Shift Focus to Organ Dysfunction. JAMA. 2016;213[8]:739-740. https://www.ncbi.nlm.nih.gov/pubmed/26903319

 

Contributed by Erik Kelly MD, Mass General Hospital, Boston, MA

What are the major changes in the definition of “sepsis” under the 3rd International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3)?