Why is my patient with systemic amyloidosis at higher risk of bleeding?

The major mechanism of bleeding tendency in primary systemic amyloidosis (AL) appears to revolve around amyloid deposit infiltration of the vasculature and musculature, leading to amyloid angiopathy, fragility, impaired vasoconstriction, tears and hemorrhage. 1,2 Other potential mechanisms include:

  • Presence of plasma inhibitors of fibrinogen conversion to fibrin
  • Deficiencies of factor X, IX and V due to their affinity for amyloid substance
  • Presence of circulating heparin-like anticoagulants
  • Uremic platelet dysfunction in the presence of renal involvement

In a study involving 36 patients with AL, ~30% had bleeding symptoms with alterations of 1 or more clotting tests found in ~85%: prolonged prothrombin time (PT) ratio (22%), activated partial thromboplastin time (aPTT) (65%) and thrombin time (85%).

Clinical manifestations of amyloidosis related to its bleeding diathesis include petechiae, ecchymoses, purpura (“raccoon eyes when periorbital), uncontrollable epistaxis, gingival bleeding, and gastrointestinal bleed or submucosal hematomas. 1-6

Due to its convenience and relative safety, a biopsy of abdominal fat or minor salivary glands is often initially performed for definitive diagnosis of amyloidosis, followed by biopsy of specific organs (eg, kidney, liver), if needed. 3,6

Due to the potential risk of bleeding complications, transjugular liver biopsy is preferred over percutaneous approach. This is because the liver capsule is not perforated with transjugular liver biopsy and if bleeding occurs, the blood returns directly into the venous system rather than into the peritoneum. 7-8 

Bonus Pearl: Did you know that AL amyloidosis is the most common type of systemic amyloidosis in western countries? This is because the incidence of the other major type of amyloidosis (AA), often related to chronic infections or inflammatory diseases, has been dropping in these countries.3

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References

  1. Gamba G, Montani N, Anesi E, et al. Clotting alterations in primary systemic amyloidosis. Haematologica 2000;85:289-92. https://moh-it.pure.elsevier.com/en/publications/clotting-alterations-in-primary-systemic-amyloidosis
  2. Marconcini LAL, Stewart FM, Sonntag L, et al. AL amyloidosis complicated by persistent oral bleeding. Case Reports in Hematology 2015, Article ID 981346. https://www.hindawi.com/journals/crihem/2015/981346/
  3. Desport E, Bridoux F, Sirac C, et al. AL Amyloidosis. Orphanet Journal of Rare Diseases 2012, 7:54. https://ojrd.biomedcentral.com/articles/10.1186/1750-1172-7-54
  4. Yoshii S, Mabe K, Nosho K, et al. Submucosal hematoma is a highly suggestive finding for amyloid light-chain amyloidosis: Two case reports. W J Gastroenterol 2012;4:434-37. https://www.ncbi.nlm.nih.gov/pubmed/23125904
  5. Kon T, Nakagawa N, Yoshikawa F, et al. Systemic immunoglobulin light-chain amyloidosis presenting hematochezia as the initial symptoms. Clin J Gastroenterol 2016;9:243. http://europepmc.org/article/med/27318996
  6. Petre S, Shah IA, Gilani N. Review article:gastrointestinal amyloidosis-clinical features, diagnosis and therapy. Alim Pharmacol Ther 2008;27:1006-16. https://www.ncbi.nlm.nih.gov/pubmed/18363891
  7. Grant A, Neuberger J. Guidelines on the use of liver biopsy in clinical practice. Gut 1999;45(Suppl IV):IV1-IV11. https://www.ncbi.nlm.nih.gov/pubmed/10485854
  8. Dohan A, Guerrache Y, Boudiaf M, et al. Transjugular liver biopsy: Indications, technique and results. Diagnostic and Interventional Imaging 2014;95:11-15. https://www.ncbi.nlm.nih.gov/pubmed/24007769
Why is my patient with systemic amyloidosis at higher risk of bleeding?

How long should I treat my patient with urinary tract infection and E. Coli bacteremia?

Although traditionally 7 to 14 days of antibiotic therapy has been recommended for Gram-negative bacteremia, more recent studies suggest that shorter antibiotic treatment courses are as effective as longer treatments for a variety of infections, particuarly those due to Enterobacteriaceae (eg, E. Coli, Klebsiella sp) in patients with low severity illness (1).

 
A 2019 randomized-controlled study involving primarily patients with bacteremia caused by E. Coli or Klebsiella sp. (~75%) with most cases associated with UTI (~70%) found that 7 days was as effective as 14 days of treatment in hemodynamically stable patients who are afebrile for at least 48 hours without an ongoing focus of infection (1). More specifically, there was no significant difference between the 2 groups in the rates of relapse of bacteremia or mortality at 14 or 28 days.

 
An accompanying editorial concluded that “7 days of treatment may be sufficient for hospitalized, non-critically ill patients with Gram-negative bacteremia and with signs of early response to treatment” (2).  Again, the accent should be on hemodynamically stable patients who respond rapidly to treatment. 

 
These articles reflect a recent overall trend in antibiotic therapy that favors shorter courses of therapy for many common infections, as nicely summarized by a 2016 article (3).
• Community-acquired pneumonia                               3-5 days (vs 7-10 days)
• Nosocomial pneumonia                                                 8 days or less (vs 10-15 days)
• Pyelonephritis                                                                  5-7 days (vs 10-14 days)
• Intraabdominal infection                                             4 days (vs 10 days)
• COPD acute exacerbation                                             5 days or less (vs >6 days)
• Acute bacterial sinusitis                                               5 days (vs 10 days)
• Cellulitis                                                                            5-6 days (vs 10 days)

 

 

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References
1. Yahav D, Franceschini E, Koppel F, et al. Seven versus 14 days of antibiotic therapy for uncomplicated Gram-negative bacteremia: A noninferiority randomized controlled trial. Clin Infect Dis 2019; 69:1091-8. https://academic.oup.com/cid/article/69/7/1091/5237874
2. Daneman D, Fowler RA. Shortening antibiotic treatment durations for bacteremia. Clin Infect Dis 2019;69:1099-1100. https://academic.oup.com/cid/article-abstract/69/7/1099/5237877?redirectedFrom=fulltext
3. Spellberg B. The new antibiotic mantra: “ Shorter is better”. JAMA Intern Med 2016;176:1254-55. https://jamanetwork.com/journals/jamainternalmedicine/article-abstract/2536180

How long should I treat my patient with urinary tract infection and E. Coli bacteremia?

Why is my diabetic patient complaining of arm pain and localized edema for couple of weeks without an obvious cause?

Aside from the usual suspects associated with a painful extremity (eg, trauma, deep venous thrombosis and soft tissue infections), think of spontaneous diabetic myonecrosis (DMN), also known as diabetic muscle infarction (1-3).

DMN is characterized by abrupt onset of painful swelling of the affected muscle, most often of the lower extremities, but also occasionally upper extremities. DMN occurs in patients with longstanding DM whose blood glucose control has deteriorated over time, often with nephropathy, retinopathy and/or neuropathy (1-3).

Couple of things to remember when considering DMN in your differential of a painful extremity. First, except for localized edema and tenderness over the involved muscle, the exam may be unremarkable. Specifically, there is no erythema or signs of compartment syndrome and fever is absent in the great majority of patients (~90%) (2). Even white blood cell count and creatine kinase (CK) are usually normal. The reason for normal CK at presentation is not clear but CK might have already peaked by the time of patient presentation (3). In contrast, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are usually elevated (>80%) (1).

MRI (without contrast in patients with renal insufficiency) is the imaging of choice with muscle enlargement and edema with hyperintense signal on T2-weighted images and other changes, including perifascial, perimuscular and or subcutaneous edema (1-3). Muscle biopsy is not currently recommended because of its adverse impact on time to symptomatic improvement. Non-surgical therapy, with rest, analgesia and glycemic control is usually recommended (1-3).

 
Though its exact cause is still unclear, atherosclerosis, diabetic microangiopathy, vasculitis with thrombosis and ischemia-reperfusion injury have been posited as potential precipitants for DMN. The role of anti-phospholipid syndrome, particularly in patients with type I DM, is unclear (1,2).

 
Bonus pearl: Did you know that symptoms of DMN may last for weeks with at least one-third of patients having a recurrence in the same muscle or elsewhere (1)?

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Reference
1. Horton WB, Taylor JS, Ragland TJ, et al. Diabetic muscle infarction: a systematic review. BMJ Open Diabetes Research and Care 2015;3:e000082.
2. Trujillo-Santos AJ. Diabetic muscle infarction. An underdiagnosed complication of long-standing diabetes. Diabetes Care 2003;26:211-15.
3. Diabetes muscle infarction in end-stage renal disease:A scoping review on epidemiology, diagnosis and treatment. World J Nephrol 2018;7:58-64.

Why is my diabetic patient complaining of arm pain and localized edema for couple of weeks without an obvious cause?

Could measurement of urinary albumin-protein ratio be useful in my patient with renal insufficiency and proteinuria?

A spot urine test for determination of albumin-protein ratio (uAPR) may be useful in distinguishing glomerular vs tubulointerstitial source of proteinuria. A low (<0.4) uAPR, defined as urinary albumin to creatinine ratio(uACR)/urinary protein to creatinine ratio (uAPR) is more suggestive of a tubulointerstitial renal disease and less suggestive of glomerular pathology.1-3  

A 2012 study involving simultaneous measurements of urinary albumin and total protein in over 1000 proteinuric patients found a relatively high (0.84) area under curve (AUC) in a receiver operating characteristic curve analysis for uAPR (vs 0.74 for uACR and 0.54 for uPCR) in discriminating between tubular and non-tubular proteinuria pattern on urine protein electrophoresis and immunofixation. An uAPR cut-off of <0.4 was found to be 88% sensitive and 99% specific for the diagnosis of primary tubulointerstitial disorders on renal biopsy.1  

Due to the limitations of this study (including a relatively small subset of patient who had renal biopsy), a related editorial concluded that a low uAPR gives a “reasonable prediction of a tubular electrophoretic proteinuria”, but that it warrants further validation. Nevertheless, uAPR could potentially be useful in patients with moderate proteinuria (>300 mg/day to <3 g/day) who have not had renal biopsy and  where assessment of likelihood of tubulointerstitial vs glomerular source of proteinuria is desired.3 Interestingly, the utility of uAPR in predicting non-glomerular source of hematuria has also been reported.4

Bonus pearl: Did you know that the negatively-charged glomerular capillary wall repels negatively charged albumin thus preventing its filtration (charge-barrier) (5)?  

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References

  1. Smith ER, Cai MMX, McMahon LP, et al. The value of simultaneous measurement of urinary albumin and total protein in proteinuric patients. Nephrol Dial Transplant 2012;27:1534-41. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4035283/
  2. Fraser SDS, Roderick PJ, McIntyre NJ, et al. Assessment of proteinuria in patients with chronic kidney disease stage 3: albuminuria and non-albumin proteinuria. PLOS ONE 2014;9:e98261. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4035283/pdf/pone.0098261.pdf
  3. Ellam T, Nahas ME. Urinary albumin to protein ratio: more of the same or making a difference. Nephrol Dial Transplant 2012;27:1293-96. https://www.ncbi.nlm.nih.gov/pubmed/22362784
  4. Ohisa N, Yoshida K, Matsuki R, et al. A comparison of urinary albumin-total protein ratio to phase-contrast microscopic examination of urine sediment for differentiating glomerular and nonglomerular bleeding. Am J Kidney Dis 2008;52:235-41. https://www.ajkd.org/article/S0272-6386(08)00828-7/pdf
  5. Venkat KK. Proteinuria and microalbuminuria in adults: significance, evaluation, and treatment. S Med J 2004;97:969-79. https://internal.medicine.ufl.edu/files/2012/07/5.18.05.04.-Proteinuria-review.pdf
Could measurement of urinary albumin-protein ratio be useful in my patient with renal insufficiency and proteinuria?

Can hypothyroidism be associated with hypertension?

Short answer: Yes! Just as hyperthyroidism, hypothyroidism is also associated with hypertension (1-5). Compared to normal subjects, patients with hypothyroidism have a 3-fold increased prevalence of hypertension, usually diastolic (2). In fact, hypothyroidism has been identified as a cause of hypertension in 3% of patients with high blood pressure and is the most common cause of secondary hypertension after renovascular hypertension (1-3).

 
High systemic vascular resistance and increased arterial stiffness are among the important mechanisms explaining hypothyroid-induced hypertension (1). High systemic vascular resistance is thought to be due to the absence of the vasodilator effects of T3 on vascular smooth muscle and decreased response to beta-adrenergic stimulation, which in turn leads to increased alpha-adrenergic responses. Increased arterial stiffness may also contribute due to the myxedema involvement of the arterial wall. Other potential factors include free water retention due to an inappropriate secretion of anti-diuretic hormone (ADH) and obesity in hypothyroid patients (1,4).

 
Similar to its prevalence in hypothyroidism, hypertension is about 3-fold higher in patients with overt hyperthyroidism compared to normal subjects (1). However, in contrast to hypothyroid patients, the hypertension in hyperthyroidism is primarily “cardiogenic”, where the increased blood pressure levels are mainly maintained by the increased cardiac output due to high stroke volume and heart rate (1).

 
Thus, both hypothyroidism and hyperthyroidism can be associated with hypertension!

 
Bonus pearl: Did you know that hypertension due to hypothyroidism is typically associated with a low-renin state, is particularly sensitive to salt intake, and may not respond as well to angiotensin -converting enzyme inhibitors (1)?

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References
1. Mazza A, Beltramello G, Armigliato M, et al. Arterial hypertension and thyroid disorders: what is important to know in clinical practice? Annales d’Endocrinologie 2011;72:296-303. https://www.sciencedirect.com/science/article/abs/pii/S0003426611000886
2. Dernellis J, Panaretou M. Effects of thyroid replacement therapy on arterial blood pressure in patients with hypertension and hypothyroidism 2002; Am Heart J 2002;143:718-24. https://www.ncbi.nlm.nih.gov/pubmed/11923811
3. Anderson GH, Blakeman N, Steeten DHP. The effect of age on prevalence of secondary forms of hypertension in 4429 consecutively referred patients. J Hypertension 1994;12:609-15. https://insights.ovid.com/hypertension/jhype/1994/05/000/effect-age-prevalence-secondary-forms-hypertension/15/00004872
4. Saito I, ITO K, Saruta T. Hypothyroidism as a cause of hypertension. Hypertension 1983;5:112-15. https://www.ahajournals.org/doi/10.1161/01.hyp.5.1.112
5. Chaker L, Bianco AC, Jonklaas J, et al. Hypothyroidism. Lancet 2017;390:1550-62. https://www.ncbi.nlm.nih.gov/pubmed/28336049

Can hypothyroidism be associated with hypertension?

Should I use aPTT or anti-Xa levels to monitor my patient on IV heparin infusion?

Despite more than half a century of use unfractionated heparin (UFH), the optimal method to monitor its anticoagulation effect remains unclear, with arguments for and against continued use of activated partial thromboplastin time, aPTT) vs switching to antifactor Xa heparin assay (anti-Xa HA). 1-4

The advantage of aPTT include decades of use and familiarity by providers, and its relative accessibility, ease of automation and cost.1 Its disadvantages include variation among the sensitivities of different aPTT reagents as well as susceptibility to factors that do not reflect intrinsic heparin activity (eg, liver dysfunction, hypercoagulable states). 1,2 Thus patients may receive unnecessarily high or low heparin doses because of physiologic and non-physiologic influences on aPTT.

In contrast, since anti-XA HA measures the inhibition of a single enzyme (factor Xa)1, it is a more direct measurement of heparin activity, with less variability and minimal interference by certain biological factors (eg, lupus anticoagulants). Anti-Xa monitoring may also improve the time to therapeutic anticoagulation and lead to fewer dose adjustments compared to aPTT monitoring.2

The disadvantages of anti-Xa HA include inaccuracy in the setting of hypertriglyceridemia (>360 mg/dL), hyperbilirubinemia (total bilirubin >6.6 mg/dL), recent use of low molecular weight heparin, fondaparinux and direct oral factor Xa inhibitors. Its relative expense and generally less laboratory availability among healthcare facilities may also limit its use in monitoring patients on therapeutic UFH. 1-3

Somewhat unsettling is the frequent discordance between aPTT and anti-Xa values having been reported in 46% to 60% of instances that may result in either thromboembolic or bleeding complications. 1,4 One study reported that aPTT may be therapeutic only 35% of the time that anti-Xa is also therapeutic! 2

What’s clearly missing are definitive studies that can shed light on the clinical impact of these intriguing findings on patient outcomes. So stay tuned!

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References

  1. Guervil DJ, Rosenberg AF, Winterstein AG, et al. Activated partial thromboplastin time versus antifactory Xa heparin assay in monitoring unfractionated heparin by continuous intravenous infusion. Ann Pharmacother 2011;45:861-68. https://www.ncbi.nlm.nih.gov/pubmed/21712506
  2. Whitman-Purves E, Coons, JC, Miller T, et al. Performance of Anti-factor Xa versus activated partial thromboplastin time for heparin monitoring using multiple nomograms. Clinical and Applied Thromosis/Hemostasis 2018;24:310-16. https://www.ncbi.nlm.nih.gov/pubmed/29212374
  3. Fruge KS, Lee YR. Comparison of unfractionated heparin protocols using antifactory XA monitoring or activated partial thrombin time monitoring. Am J Health-System Pharmacy. 2015; 72: S90-S97, https://doi.org/10.2146/sp150016
  4. Samuel S, Allison TA, Sharaf S, et al. Antifactor XA levels vs activated partial thromboplastin time for monitoring unfractionated heparin. A pilot study. J Clin Pharm Ther 2016;41:499-502.
  5. doi:10.1111/jcpt.12415. https://www.ncbi.nlm.nih.gov/pubmed/27381025
Should I use aPTT or anti-Xa levels to monitor my patient on IV heparin infusion?

My patient with jaundice complains of abdominal fullness. How useful is the history or physical exam when assessing for ascites?

Even in the age of ultrasound, history and physical exam can be useful in assessing for ascites.

History is a good place to start. Of all the questions we often ask when we suspect ascites (eg, increasing abdominal girth, weight gain and ankle swelling), lack of report of ankle swelling is probably the most helpful in excluding ascites (negative likelihood ratio [LR-], 0.1 in a study involving men), followed by no increase in abdominal girth (LR-, 0.17). Conversely, patient reported ankle swelling or increasing abdominal girth may be helpful in suspecting ascites (LR+ 4.12 and 2.8, respectively). 1

Of the various physical signs and maneuvers, absence of peripheral edema is highly associated with the lack of ascites, followed by lack of shifting dullness or fluid wave (LR-, 0.2, 0.3, 0.4, respectively). The presence of a fluid wave may be the most helpful in suspecting ascites, followed by peripheral edema, and shifting dullness (LR+ 6.0, 3.8, 2.7, respectively). 1  Relatively high sensitivities have been reported for shifting dullness (83-88%), while relatively high specificities have been reported for the fluid wave test (82-90%).2,3 An elevated INR may also improve the positive predictive value of shifting dullness and fluid waves.4

So if you don’t get a history of ankle edema and find no evidence of peripheral edema or shifting dullness on exam, the likelihood of ascites is pretty low. On the other hand, if you find a positive fluid wave, you can be pretty sure that the patient has ascites.

Of course, the actual likelihood of detecting ascites also depends on several other factors, including your pre-test probability and the volume of the ascites in the abdominal cavity, with at least ~500 ml of ascites necessary before it can be detected on exam (vs ~100 ml for ultrasound). 2,5

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References

  1. Williams JW, Simetl DL. Does this patient have ascites? How to divine fluid in the abdomen. JAMA 1992;267: 2645-48. https://jamanetwork.com/journals/jama/fullarticle/397285
  2. Cattau EL, Benjamin SB, Knuff TE, et al The accuracy of the physical examination in the diagnosis of suspected ascites. JAMA 1982;247:1164-66. https://www.ncbi.nlm.nih.gov/pubmed/7057606
  3. Cummings S, Papadakis M, Melnick J, et al. The predictive value of physical examinations for ascites. West J Med 1985;142:633-36. https://www.ncbi.nlm.nih.gov/pubmed/3892916
  4. Fitzgerald FT. Physical diagnosis versus modern technology. A review. West J Med 1990;152:377-82. https://www.ncbi.nlm.nih.gov/pubmed/2190412
  5. CDC. Assessment for ascites. https://www.cdc.gov/dengue/training/cme/ccm/Assess%20for%20Ascites_F.pdf. Accessed November 13, 2019.
My patient with jaundice complains of abdominal fullness. How useful is the history or physical exam when assessing for ascites?

My patient with peripheral neuropathy was just diagnosed with monoclonal gammopathy of unclear significance (MGUS). Can these two conditions be related?

The presence of MGUS in patients with peripheral neuropathy (PN) may be either coincidental or causal. Younger age group (<50 y) and the presence of IgM MGUS increase the likelihood of a causal relationship between MGUS and peripheral neuropathy. 1

The likelihood of a causal relationship is higher in the younger age group because of the very low prevalence of M proteins (less than 1.5%) in this population making coincidental presence of MGUS and PN much less likely. In contrast, this relationship may just be coincidental in older patients because of higher baseline prevalence of MGUS (7% in those over 70 y old). 1  

Similarly, a causal relationship between MGUS and PN may be more likely when the M protein is IgM (vs IgG or IgA). In a study of patients with MGUS and peripheral neuropathy,  31% of patients with IgM MGUS had neuropathy vs 14% for IgA and 6% for IgG MGUS. In fact, among patients with PN without an obvious cause, the prevalence of an M protein may be as high as 10%.2  Whether the relationship between non-IgM MGUS and PN is causal remains unclear.3

Although the exact mechanism of MGUS-related PN is not known, pathologic studies in Waldenstrom macroglobulinemia and multiple myeloma have demonstrated demyelination and widened myelin lamellae associated with monoclonal IgM deposits.1

But before you implicate MGUS as the cause of PN, make sure to exclude common causes of PN, such as diabetes mellitus, alcoholism and potential drugs.

 

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References

  1. Chaudhry HM, Mauermann ML, Rajkumar SV. Monoclonal gammopathy—associated peripheral neuropathy: diagnosis and management. Mayo Clin Proc 2017; 92:838-50. https://www.mayoclinicproceedings.org/article/S0025-6196(17)30118-0/pdf
  2. Kelly JJ Jr, Kyle RA, O’Brien PC, et al. Prevalence of monoclonal protein in peripheral neuropathy. Neurology 1981;31:1480-83. https://www.ncbi.nlm.nih.gov/pubmed/6273767
  3. Nobile-Orazio E, Barbien L, Baldini L, et al. Peripheral neuropathy in monoclonal gammopathy of undetermined significance: prevalence and immunopathogenetic studies. Acta neurol Scand 1992;85:383-90. https://onlinelibrary.wiley.com/doi/10.1111/j.1600-0404.1992.tb06033.x
My patient with peripheral neuropathy was just diagnosed with monoclonal gammopathy of unclear significance (MGUS). Can these two conditions be related?

How can I distinguish serotonin syndrome from neuroleptic malignant syndrome in my patient with fever and mental status changes?

Although there is often an overlap between the clinical presentation of serotonin syndrome (SS) and neuromuscular malignant syndrome (NMS), start out with the physical exam. The presence of hyperreflexia, tremors, clonus, hyperactive bowel sounds, and dilated pupils should make you think of SS, whereas hyporeflexia, “lead-pipe” rigidity in all muscle groups, normal pupils, and normal or decreased bowels sounds suggest NMS in the proper context.1-3 The most sensitive and specific sign of SS is clonus.1

Aside from physical exam findings, symptom onset in relation to the implicated drug may also be important. Onset of symptoms within 12-24 h of the initiation or change of an implicated drug suggests SS, whereas a more delayed onset (often 1-3 days) is more supportive of NMS.1-3  SS also tends to resolve within a few days after discontinuation of the offending agent, while NMS usually takes 9-14 days to resolve. 1-3 Although both SS and NMS can be associated with leukocytosis, elevated CK and low serum iron levels are more common in NMS.2

SS is caused by excess serotonin due to a variety of mechanisms—therefore medications— including inhibition of serotonin uptake ( eg, serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, tricyclic antidepressants, metoclopramide, ondansetron), inhibition of serotonin metabolism (seen with monoamine oxidase inhibitors , including linezolid, methylene blue), increased serotonin release (eg stimulants, including amphetamines, cocaine), and activation of serotonin receptors (eg, lithium), among others. 2

As for medications that can cause NMS, look for neuroleptic agents (eg, haloperidol, olanzapine, quetiapine, risperidone), as well as antiemeics, such as metoclopramide and promethazine.2

 

Bonus Pearl: Did you know that several supplements/herbal products have been associated with serotonin syndrome, including L-tryptophan, St. John’s wort and ginseng?1

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References

  1. Bienvenu OJ, Neufeld K, Needham DM. Treatment of four psychiatric emergencies in the intensive care unit. Crit Care Med 2012;40: 2662-70. https://insights.ovid.com/crossref?an=00003246-201209000-00017
  2. Turner AAH, Kim JJ, McCarron RM, et al. Differentiating serotonin syndrome and neuroleptic malignant syndrome. Current Psychiatry 2019;18: 36. https://www.mdedge.com/psychiatry/article/193418/schizophrenia-other-psychotic-disorders/differentiating-serotonin-syndrome
  3. Dosi R, Ambaliya A, Joshi H, et al. Serotonin syndrome versus neuroleptic malignant syndrome: a challenging clinical quandary. BMJ Case Rep 2014. Doi:10.1136/bcr-2014-204154. https://casereports.bmj.com/content/2014/bcr-2014-204154

 

How can I distinguish serotonin syndrome from neuroleptic malignant syndrome in my patient with fever and mental status changes?

Is there any evidence that routinely wearing gowns and gloves upon entry into the rooms of patients on contact precautions for MRSA or VRE really works?

Although routine gowning and gloving in the care of hospitalized patients with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE)—also known as contact precautions (CP)— is considered a standard of care (1), the evidence supporting its effectiveness in preventing endemic hospital-associated multidrug-resistant organism (MDROs) infections is not robust and is often conflicting. In fact, this practice is increasingly being questioned (including by some hospital epidemiologists) as means of preventing endemic transmission of MDROs in hospitals (1-7).
Critics often point out that studies supporting the use of CP in MDROs are observational, involving only outbreak situations where they were instituted as part of a bundled approach (eg, improved hand hygiene), making it difficult to determine its relative contribution to infection prevention (2,6).
In fact, recent cluster-randomized trials have largely failed to demonstrate clear benefit of CP over usual care for the prevention of acquiring MRSA or VRE in hospitalized patients (2,4). Furthermore, a meta-analysis of studies in which CP were eliminated failed to find an increase in the subsequent rates of transmission of MRSA, VRE, or other MDROs (2,7).
Based on these and other studies, some have suggested that in the presence of other infection prevention measures (eg, hand hygiene monitoring), CP be implemented only in select circumstances such as open or draining wounds, severe diarrhea or outbreak situations (3).

 

The United States Centers for Disease Control and Prevention (CDC), along with the Infectious Diseases Society of America (IDSA) and the Society of Healthcare Epidemiologists of America (SHEA), however, continue to recommend implementation of CP in the care of patients with MDROs.  

 

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References
1. Maragakis LL, Jernigan JA. Things we do for good reasons: contact precautions for multidrug-resistant organisms, including MRSA and VRE. J Hosp Med 2019;14:194-6. https://www.ncbi.nlm.nih.gov/pubmed/30811332
2. Young K, Doernberg SB, Snedcor RF, et al. Things we do for no reason:contact precautions for MRSA and VRE. J Hosp Med 2019;14:178-80. https://www.ncbi.nlm.nih.gov/pubmed/30811326
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Is there any evidence that routinely wearing gowns and gloves upon entry into the rooms of patients on contact precautions for MRSA or VRE really works?