Inflammation

Is my patient with varicose veins at higher risk of venous thromboembolism?

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

Although varicose veins are common and usually not associated with serious health complications, increasing scientific evidence suggests that they are associated with increased risk of subsequent incident deep venous thrombosis (DVT) and pulmonary embolism (PE). 1-3

A 2018 retrospective cohort study involving patients with the diagnosis of varicose veins and controls (>200,000 subjects each) based on claims data from Taiwan found a higher incidence rate of DVT among cases (hazard ratio [HR] 5.3, 95%C.I. 5.1-5.6). Increased risk of DVT with varicose veins was reported in all age groups but decreased with increasing age.  The HR was higher within the first year of the diagnosis of varicose veins. 1

In the same study, the incidence of PE was higher among participants with varicose veins (HR 1.7 95% C.I. 1.5-1.9).  Again, the association did not significantly differ by age.1  Other smaller studies have found similar association between DVT and varicose veins. 2,3

Although these studies at best demonstrate an association (not necessarily a cause and effect relationship) between varicose veins and venous thromboembolism, several possible explanations have been posited. Animal studies have demonstrated higher concentrations of macrophages, monocytes, neutrophils, lymphocytes, and matrix metalloproteinases in venous valves exposed to high pressure for prolonged periods.  The resultant inflammatory state in patients with varicose veins may in turn promote a prothrombotic state contributing to venous thromboembolism. 1,4

Bonus Pearl: Did you know that nearly 1 of 4  adults in the United States have been reported to have varicose veins?

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References

  1. Chang SL, Huang YL, Lee MC, et al. Association of varicose veins with incident venous thromboembolism and peripheral artery disease. JAMA 208;319:807-817. https://jamanetwork.com/journals/jama/fullarticle/2673551
  2. Muller-Buhl U, Leutgeb R, et al. Varicose veins are a risk factor for deep venous thrombosis in general practice patients. Vasa 2012;41:360-65. https://pubmed.ncbi.nlm.nih.gov/22915533/
  3. Engbers MJ, Karasu A, Blom JW, et al. Clinical features of venous insufficiency and the risk of venous thrombosis in older people. Br J Haematol 2015;171:417-23. https://pubmed.ncbi.nlm.nih.gov/26221838/
  4. Riva N, Donadini MP, Ageno W. Epidemiology and pathophysiology of venous thromboembolism: similarities with atherothrombosis and the role of inflammation. Thromb Haemost 2015;113:1176-1183. https://pubmed.ncbi.nlm.nih.gov/25472800/

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!

Is my patient with varicose veins at higher risk of venous thromboembolism?

Do statins have a role in treating novel Coronavirus infection, COVID-19?

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

There is currently no firm clinical evidence that statins improve the outcome of COVID-19. However, there are some theoretical reasons for believing that statins may have a role in the treatment of COVID-19.  That’s because beyond their cholesterol lowering action, statins may also have clinically relevant anti-inflammatory and antiviral (pleotropic) properties.  

Anti-inflammatory: Anti-inflammatory effect of statins is well known and is thought to occur through a variety of molecular pathways of the innate and adaptive immune systems as well as attenuation of several circulating proinflammatory cytokines.1 Although observational studies have suggested that statins lower hospitalization and mortality among outpatients hospitalized with infection, pneumonia or sepsis, several randomized controlled trials (RCTs) have failed to show any mortality benefit among ICU patients with sepsis and ARDS treated with statins.2

In contrast, an RCT involving patients with sepsis (majority with pneumonia, mean CRP 195 mg/dL) reported significant reduction in progression to severe sepsis among statin-naïve patients  placed on atorvastatin 40 mg/day at the time of hospitalization.3 So, perhaps timing of statin therapy before florid sepsis and ARDS is an important factor.  

Some have suggested that statins may decrease the fatality rate of a related Coronavirus, Middle East Respiratory Syndrome (MERS) virus, by blunting exuberant inflammatory response that may result in a fatal outcome. 4

Antiviral: Statins may also have antiviral properties, including activity against influenza, hepatitis C virus, Zika and dengue viruses.2,5 Whether statins have activity against coronaviruses such as the agent of COVID-19 is unclear at this time.

It’s interesting to note that cholesterol may have an important role in the membrane attachment, fusion and replication of many enveloped viruses, including influenza.5 Covid-19 is also an enveloped virus.

So what do we do? Based on the current data, it makes sense to continue statins in patients who have known clinical indications for their use and no obvious contraindications because of COVID-19 (eg. rhabdomyolysis).6 As for statin-naïve patients, particularly those in early stages of sepsis and increased risk of cardiovascular events, benefit may outweigh the risk.  Only proper clinical studies will give us more definitive answers.

Bonus Pearl: Did you know that lipids make up a major component of the envelope in enveloped viruses and that cholesterol makes up nearly one-half of total lipid and over 10% the total mass of influenza viruses?

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References

  1. Tousoulis D, Psarros C, Demosthenous M, et al. Innate and adaptive inflammation as a therapeutic target in vascular diseae: The emerging role of statins. J Am Coll Cardiol 2014;63:2491-2502. https://www.sciencedirect.com/science/article/pii/S0735109714011553?via%3Dihub
  2. Fedson DS. Treating the host response to emerging virus diseases: lessons learned from sepsis, pneumonia, influenza and Ebola. Ann Transl Med 2016;4:421. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5124618/pdf/atm-04-21-421.pdf
  3. Patel JM, Snaith C, Thickette DR. Randomized double-blind placebo-controlled trial of 40 mg/day of atorvastatin in reducing the severity of sepsis in ward patients (ASEPSIS Trial) Critical Care 2012;16:R231. https://ccforum.biomedcentral.com/track/pdf/10.1186/cc11895
  4. Espano E, Nam JH, Song EJ, et al. Lipophilic statins inhibit Zika virus production in Vero cells. Scientific Reports 2019;9:11461. https://www.nature.com/articles/s41598-019-47956-1
  5. Sun X, Whittaker GR. Role for influenza virus envelope cholesterol in virus entry and infection. J Virol 2003;77:12543-12551. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC262566/
  6. Virani SS. Is there a role for statin therapy in acute viral infections. Am Coll Cardiol March 18, 2020. https://www.acc.org/latest-in-cardiology/articles/2020/03/18/15/09/is-there-a-role-for-statin-therapy-in-acute-viral-infections-covid-19

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Massachusetts General Hospital, Harvard Catalyst, Harvard University, its affiliate academic healthcare centers, or its contributors. 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!

Do statins have a role in treating novel Coronavirus infection, COVID-19?

Why might hydroxychloroquine and azithromycin be effective against the novel Coronavirus SARS-CoV-2/Covid-19?

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

Repurposing of older drugs such as chloroquine or hydroxychloroquine (HC) and more recently, azithromycin (AZ), has received much attention recently in the treatment of Covid-19. Both HC and AZ have immune modulating and antiviral activity that may potentially be effective in our fight against Covid-19.

 
Chloroquine/HC: Chloroquine is an old drug used for its antimalarial activity as well as for its immune modulation and anti-inflammatory properties. It is active in mice against a variety of viruses, including some enteroviruses, Zika virus, and influenza A H5N1 (1). Both chloroquine and HC are active in vitro against Covid-19, though HC appears to be more active (2).

 
Azithromycin: A macrolide often used for treatment of bacterial respiratory tract infections but also with anti-inflammatory and antiviral activity. Azithromycin has been shown to augment interferon response in rhinovirus-infected bronchial epithelial cells as well as in an experimental mouse model of asthma exacerbation (3,4). It also has activity against Zika virus (5). As recently as 2016, some authors opined that macrolides may be useful in pandemic influenza characterized by excessive inflammatory cytokine production because of their anti-inflammatory and interferon-boosting potential (6).

 
March 2020 French clinical trial: A small non-randomized clinical trial involving 36 confirmed Covid-19 patients (mean age 45 y) reported that HC (200 mg 3x/day x 10 days) was associated with rapid viral clearance from nasopharynx, often within 3-6 days (7). The effect was even more pronounced when AZ (500 mg 1st day, followed by 250 mg daily x 4 days) was added in 6 patients.

It’s worth emphasizing that most subjects in this study were either asymptomatic (17%) or had mild disease with upper respiratory tract infection symptoms only (61%). Pneumonia was diagnosed in only 6 patients.  A significant number of patients in the treatment arm also dropped out of the study, some due to ICU transfer.

 
Although such preliminary reports appear promising, the proof of the efficacy and safety of HC and/or AZ in the treatment of Covid-19 awaits larger properly designed clinical studies. Stay tuned!

 

 

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References
1. Touret F, de Lamballerie X. Of chloroquine and COVID-19. Antiviral Research 2020;177. 104762. https://www.ncbi.nlm.nih.gov/pubmed/32147496
2. Yao X, Ye F, Zhang M, et al. In vitro antiviral activity and projection of optimized dosing design of hydroxychloroquine for the treatment of severe acute respirartory syndrome coronavirus 2 (SARS-CoV-2). Clin Infect Dis 2020, March 9. https://www.ncbi.nlm.nih.gov/pubmed/32150618
3. Menzel M, Akbarshai H, Bjermer L, et al. Azithromycin induces anti-viral effects in cultured bronchial epithelial cells from COPD patients. Scientific Reports 2016;6:28698. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4923851/
4. Menzel M, Akbarshai H, Uller L. Azithromycin exhibits interferon-inducing properties in an experimental mouse model of asthma exacerbation. Eur Resp J 2015;46:PA5095. https://erj.ersjournas.com/content/46/suppl_59/PA5095
5. Retallack H, Di Lullo E, Knopp AC, et al. Zika virus cell tropism in the developing human brain and inhibition by azithromycin. Proc Nat Acad Sci USA 2016;113:14408-13. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5167169/
6. Porter JD, Watson J, Roberts LR, et al. Identification of novel macrolides with antibacterial, anti-inflammatory and type I and III-IFN-augmenting activity in airway epithelium. J Antimicrob Chemother 2016;71:2767-81. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5031920/
7. Gautret P, Lagier JC, Parola P, et al. Hydroxychloroquine and azithromycin as a treatment of COVID-19:results of an open-label non-randomized clinical trial. International Journal of Antimicrobial Agents—In Press 17 March 2020-DOI: 10.1016/j.ijantimicag.2020.105949 . https://www.sciencedirect.com/science/article/pii/S0924857920300996

 

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Massachusetts General Hospital, Harvard Catalyst, Harvard University, its affiliate academic healthcare centers, or its contributors. 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!

Why might hydroxychloroquine and azithromycin be effective against the novel Coronavirus SARS-CoV-2/Covid-19?

What existing drugs are currently being evaluated or repurposed for treatment of Coronavirus (Covid-19) infection?

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

There are currently no drugs specifically approved for treatment of Covid-19 infections. However, there are legions of therapies that are being considered, tried, and/or evaluated in clinical trials. Many experts believe a combination of drugs may be necessary for optimal therapy. Here is my select list of potentially promising drugs from gleaning the literature and online resources to date.1-16

  • Remdisivir: A broad spectrum investigational nucleoside analogue, originally developed to treat a variety of viruses, including Ebola, SARS and MERS. Active in vitro against Covid-19. Favorable results have been reported in some cases, including the first reported patient in the U.S.
  • Chloroquine: An old drug used for its antimalarial activity as well as for its immune modulation and anti-inflammatory properties. Has also been found to be active in mice against a variety of viruses, including certain enteroviruses, Zika virus, influenza A H5N1.  Active in vitro against Covid-19, though hydroxychloroquine may be more effective. Evidence for its efficacy in treating acute viral infections in humans is currently lacking.
  • Lopinavir/ritonavir: Protease inhibitor combo used in HIV infection with possibly some benefit in the treatment of SARS. Recent study showed no significant efficacy in severe Covid-19 disease. 
  • Interferon-alpha: An antiviral cytokine used against hepatitis B and C viruses. May be more effective for prophylaxis than post-exposure, based on experimental animal studies involving SARS.
  • Ribavirin: Another nucleoside analogue approved for hepatitis C (in combination with other drugs) and respiratory syncytial virus (RSV) infections but also evaluated in SARS and MERS. Has been reported to be active in vitro against Covid-19.
  • Sofosbuvir: Inhibits RNA-dependent RNA polymerase. Approved for treatment of hepatitis C, but also with in vitro activity against Covid-19.
  • Tocilizumab: Anti-interleukin-6 monoclonal antibody used in rheumatoid and giant cell arthritis. Theoretically, may mitigate cytokine storm observed in some patients during the later stages of Covid-19 disease.

Of course, there are many more drugs some of which would not be expected to be effective against Covid-19, based on what we so far know this virus. These include darunavir/cobicistat, oseltamivir, immunoglobulins, arbidol (an antiviral used in Russia and China vs influenza), angiotensin receptor blockers, stem cell therapy, convalescent plasma, and traditional Chinese medicine.

Remember corticosteroids are currently not recommended in the absence of other indications for their use (see related PEARL).

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References

  1. US National Library of Medicine. https://clinicaltrials.gov/ct2/results?cond=2019nCoV&term=&cntry=&state=&city=&dist
  2. Li Guangdi, De Clercq E. Therapeutic options for the 2019 novel coronavirus (2019-nCoV). Nature Reviews Drug Discovery 2020; Feb 19, 2010. https://www.nature.com/articles/d41573-020-00016-0
  3. Harrison C. Coronavirus puts drug repurposing on the fast track. Nature Biotechnology 020, Feb 27. https://www.nature.com/articles/d41587-020-00003-1
  4. Velavan TP, Meyer CG. The COVID-19 epidemic. Tropical Medicine and International Health 2020;25:278-280. https://onlinelibrary.wiley.com/doi/full/10.1111/tmi.13383
  5. Elfiky AA. Anti-HCV, nucleotide inhibitors, repurposing against COVID-19. Life Sciences 2020;248. 11747. https://www.sciencedirect.com/science/article/pii/S0024320520302253
  6. Wang Y, Wang Y, Chen Y, et al. Unique epidemiological and clinical features of the emerging 2019 novel coronavirus pneumonia (COVID-19) implicate special control measures. J Med Virol 2020;March 5. https://www.ncbi.nlm.nih.gov/pubmed/32134116
  7. Huang C, Wang Y, Li X, et al. Clinical features of patients infected with 2029 novel coronavirus in Wuhan, China. Lancet 2020;395:497-506. https://www.ncbi.nlm.nih.gov/pubmed/31986264
  8. Paules CI, Marston HD, Fauci AS. Coronavirus infections—More than just the common cold. JAMA 2020;323:707-78. https://jamanetwork.com/journals/jama/fullarticle/2759815
  9. Touret F, de Lamballerie X. Of chloroquine and COVID-19. Antiviral Research 2020;177. 104762. https://www.sciencedirect.com/science/article/pii/S0166354220301145
  10. Gurwitz D. Angiotensin receptor blockers as tentavie SARS-CoV-2 therapeutics. https://www.ncbi.nlm.nih.gov/pubmed/32129518/
  11. Wang M, Cao R, Zhang L, et al. Remdesivir and chlorquine effectively inhibit the recently emerged novel coronavirus (2019-nCoV) in vitro. Cell Research 2020;30:269-71. https://www.nature.com/articles/s41422-020-0282-0
  12. Roques P, Thiberville SD, Dupuis-Maguirara L, et al. Paradoxical effect of chloroquine treatment in enhancing Chikungunya virus infection. Viruses 2018;10, 268. https://www.ncbi.nlm.nih.gov/pubmed/29772762
  13. Young BE, Ong SWX, Kalimuddin S, et al. Epidemiologic features and clinical course of patients infected with SARS-CoV-2 in Singapore. JAMA 2020;March 3. https://jamanetwork.com/journals/jama/fullarticle/2762688
  14. Holshue ML, DeBolt C, Lindquist S, et al. First case of 2019 novel coronavirus in the United States. N Engl J Med 2020; March 5. https://www.nejm.org/doi/full/10.1056/NEJMoa2001191
  15. Yao X, Ye F, Zhang M, et al. In vitro antiviral activity and projection of optimized dosing design of hydroxychloroquine for the treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Clin Infect Dis 2020. March 9. https://www.ncbi.nlm.nih.gov/pubmed?term=32150618
  16. Cao B, Wang Y, Wen D, et al. A trial of lopinavir-ritonavir in adults hospitalized with severe Covid-19. N Engl M Med 2020, March18. DOI:10.1056/NEJMoa2001282. https://www.nejm.org/doi/full/10.1056/NEJMoa2001282

 

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Massachusetts General Hospital, Harvard Catalyst, Harvard University, its affiliate academic healthcare centers, or its contributors. 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!

What existing drugs are currently being evaluated or repurposed for treatment of Coronavirus (Covid-19) infection?

Should I consider acute acalculous cholecystitis in my elderly ambulatory patient admitted with right upper quadrant pain?

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

Short answer: Yes! Although we usually associate acute acalculous cholecystitis (AAC) with critically ill patients (eg, with sepsis, trauma, shock, major burns) in ICUs, AAC is not as rare as we might think in ambulatory patients. In fact, a 7 year study of AAC involving multiple centers reported that AAC among outpatients was increasing in prevalence and accounted for 77% of all cases (1)!

 
Although the pathophysiology of ACC is not fully understood, bile stasis and ischemia of the gallbladder either due to microvascular or macrovascular pathology have been implicated as potential causes (2). One study found that 72% of outpatients who developed ACC had atherosclerotic disease associated with hypertension, coronary, peripheral or cerebral vascular disease, diabetes or congestive heart failure (1). Interestingly, in contrast to calculous cholecystitis, “multiple arterial occlusions” have been observed on pathological examination of the gallbladder in at least some patients with ACC and accordingly a name change to “acute ischemic cholecystitis” has been proposed (3).

 
AAC can also complicate acute mesenteric ischemia and may herald critical ischemia and mesenteric infarction (3). The fact that cystic artery is a terminal branch artery probably doesn’t help and leaves the gallbladder more vulnerable to ischemia when arterial blood flow is compromised irrespective of the cause (4).

 
Of course, besides vascular ischemia there are numerous other causes of ACC, including infectious (eg, viral hepatitis, cytomegalovirus, Epstein-Barr virus, Salmonella, brucellosis, malaria, Rickettsia and enteroviruses), as well as many non-infectious causes such as vasculitides and, more recently, check-point inhibitor toxicity (1,5-8).

 
Bonus Pearl: Did you know that in contrast to cholecystitis associated with gallstones (where females and 4th and 5th decade age groups predominate), ACC in ambulatory patients is generally more common among males and older age groups (mean age 65 y) (1)?

 

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References
1. Savoca PE, Longo WE, Zucker KA, et al. The increasing prevalence of acalculous cholecystitis in outpatients: Result of a 7-year study. Ann Surg 1990;211: 433-37. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1358029/pdf/annsurg00170-0061.pdf
2. Huffman JL, Schenker S. Acute acalculous cholecystitis: A review. Clin Gastroenterol Hepatol 2010;8:15-22. https://www.cghjournal.org/article/S1542-3565(09)00880-5/pdf
3. Hakala T, Nuutinene PJO, Ruokonen ET, et al. Microangiopathy in acute acalculous cholecystitis Br J Surg 1997;84:1249-52. https://bjssjournals.onlinelibrary.wiley.com/doi/abs/10.1046/j.1365-2168.1997.02775.x?sid=nlm%3Apubmed
4. Melo R, Pedro LM, Silvestre L, et al. Acute acalculous cholecystitis as a rare manifestation of chronic mesenteric ischemia. A case report. Int J Surg Case Rep 2016;25:207-11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4941110/
5. Aguilera-Alonso D, Median EVL, Del Rosal T, et al. Acalculous cholecystitis in a pediatric patient with Plasmodium falciparum infection: A case report and literature review. Ped Infect Dis J 2018;37: e43-e45. https://journals.lww.com/pidj/pages/articleviewer.aspx?year=2018&issue=02000&article=00020&type=Fulltext  
6. Kaya S, Eskazan AE, Ay N, et al. Acute acalculous cholecystitis due to viral hepatitis A. Case Rep Infect Dis 2013;Article ID 407182. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3784234/pdf/CRIM.ID2013-407182.pdf
7. Simoes AS, Marinhas A, Coelho P, et al. Acalculous acute cholecystitis during the course of an enteroviral infection. BMJ Case Rep 2013;12. https://casereports.bmj.com/content/12/4/e228306
8. Abu-Sbeih H, Tran CN, Ge PS, et al. Case series of cancer patients who developed cholecystitis related to immune checkpoint inhibitor treatment. J ImmunoTherapy of Cancer 2019;7:118. https://jitc.biomedcentral.com/articles/10.1186/s40425-019-0604-2

 

 

Should I consider acute acalculous cholecystitis in my elderly ambulatory patient admitted with right upper quadrant pain?

My postop patient now has fever with atelectasis on her chest X-ray one day after surgery. Does atelectasis cause fever?

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

Although fever and atelectasis often coexist during the early postop period, there is no evidence that atelectasis causes fever.

A 2011 systematic analysis of 8 published studies found that all but 1 study failed to find a significant association between postop fever and atelectasis.1  A 1988 study reported a significant association between postop fever during the first 48 h and atelectasis on day 4 postop, but not each postop day.2  Even in this study, however, fever as a predictor of atelectasis performed poorly with a sensitivity of 26%, specificity of 75% and accuracy of 43%.

In another study involving postop cardiac surgery patients, despite a fall in the incidence of fever from day 0 to day 2, the incidence of atelectasis based on serial chest X-rays actually  increased. 3

Experimental studies in dogs and cats in the 1960s also support the lack of a causative relationship between atelectasis and fever. 4,5 Although fever was observed within 12 hrs of placement of cotton plugs in the left main bronchus of these animals, almost all animals also developed pneumonia distal to the plug.  Antibiotic treatment was associated with resolution of fever but not atelectasis.

So if it’s not atelectasis, what’s the explanation for early postop fever? The great majority of postop fevers during the first 4 days postop are unlikely to be related to infections. Instead, a more plausible explanation is the inflammatory response to the tissue injury as a result of the surgery itself causing release of cytokines (eg, interleukin-1 and -6 and tumor necrosis factor) associated with fever. 6

References

  1. Mavros MN, Velmahos GC, Falagas ME. Atelectasis as a cause of postoperative fever. Where is the clinical evidence? CHEST 2011;140:418-24. https://www.ncbi.nlm.nih.gov/pubmed/21527508
  2. Roberts J, Barnes W, Pennock M, et al. Diagnostic accuracy of fever as a measure of postoperative pulmonary complications. Heart Lung 1988;17:166-70. https://www.ncbi.nlm.nih.gov/pubmed/3350683
  3. Engoren M. Lack of association between atelectasis and fever. CHEST 1995;107:81-84. https://www.ncbi.nlm.nih.gov/pubmed/7813318
  4. Lansing AM, Jamieson WG. Mechanisms of fever in pulmonary atelectasis. Arch Surg 1963;87:168-174. https://jamanetwork.com/journals/jamasurgery/fullarticle/561080
  5. Jamieson WG, Lansing AM. Bacteriological studies in pulmonary atelectasis. Arch Surg 1963;87:1062-66. https://www.ncbi.nlm.nih.gov/pubmed/14063816
  6. Narayan M, Medinilla SP. Fever in the postoperative patient. Emerg Med Clin Nam 2013;31:1045-58. https://www.ncbi.nlm.nih.gov/pubmed/24176478 

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My postop patient now has fever with atelectasis on her chest X-ray one day after surgery. Does atelectasis cause fever?