Pulmonary diseases

Why Does My Young Female Patient Have Recurrent Spontaneous Pneumothoraces?

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

Causes of spontaneous pneumothorax are legion, including cigarette use, genetic predisposition, or most commonly subpleural bleb rupture. 1 However, in cases without an apparent cause, a young female patient with recurrent spontaneous pneumothorax should routinely be asked about the timing of the pneumothorax in relation to her menstrual periods.  If related, catamenial pneumothorax (CP)— also known as menses-associated pneumothorax—should also be considered.  

CP is commonly defined as 2 or more episodes of spontaneous pneumothoraces occurring within 72 hours of onset of menstruation. 2, 3 Classically, CP occurs in females between the ages of 30-40 years with a history of endometriosis and recurrent right-sided pneumothorax.

As for potential mechanisms to explain catamenial pneumothorax, several theories have been proposed, including the passage of air through the vagina and uterus during times of decreased cervical mucus production and peritoneal cavity into the pleural space via diaphragmatic fenestrations. 3 Another potential mechanism is the retrograde migration of endometrial tissue from the uterine lining via the right paracolic gutter into the pleural space through defects in the diaphragm. Endometrial necrosis following monthly cycles may then create air blebs and pneumothorax. 3,4 Although CP is the most common presentation of thoracic endometriosis, a diagnosis of endometriosis is not required for its diagnosis.3, 5

Initial evaluation of CP often includes chest X-ray, CT, or MRI which may show not only pneumothorax but also diaphragmatic nodules or fenestrations; CA-125 levels may also be elevated in CP due to endometriosis. 2,3,9  Endometriosis-related CP is diagnosed via video-assisted thoracoscopic surgery (VATS).  

Treatment includes surgical and medical options but, ultimately, the goal is to prevent recurrence which is more likely in CP compared to other pneumothoraces. 3, 6 Surgical approaches such as VATS, pleurodesis, and diaphragmatic plication or repair with mesh, may be considered but recurrence rates (8-40%) are common. 3,7 Treatment options also include hormone-suppression therapy resulting in atrophy of ectopic endometrial glands (eg, estrogen-progesterone oral contraceptives and gonadotropin-releasing-hormone [GNRH] agonists such as leuprolide). 2, 7

Bonus Pearl: Did you know that a condition called catamenial epilepsy also clusters around menstruation due to the diminished protective effect of progesterone against seizures?  10

Contributed by Mariam Krikorian, Medical Student (Lincoln Memorial University) Mercy Hospital-St. Louis

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References

  1. Sahn, Steven A., Heffer, John E. Spontaneous Pneumothorax. N Engl J Med. 2000;342:858-874. https://www-nejm-org.lmunet.idm.oclc.org/doi/10.1056/NEJM200003233421207?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed.
  2. Haga, T., Kumasaka, T., Kurihara, M, etal. Immunohistochemical Analysis of Thoracic Endometriosis. Path Intl, 2013;63(9);429-434. https://onlinelibrary.wiley.com/doi/10.1111/pin.12089.
  3. Visouli, A. N., Zarogoulidis, K., Kougioumtzi, I., etal. Catamenial Pneumothorax. J Thora Dis. 2014;6(4). https://jtd.amegroups.com/article/view/3205/html.
  4. Rousset-Jablonski, C., Alifano, M., Plu-Bureau, G., etal. A. Catamenial Pneumothorax and Endometriosis-Related Pneumothorax: Clinical Features and Risk Factors. Mol Hum Reprod. 2011;26(99);2322-2329. https://academic.oup.com/humrep/article/26/9/2322/720483.
  5. Korom, S., Canyurt, H., Missbach, A., etal. Catamenial Pneumothorax Revisited: Clinical Approach and Systematic Review of the Literature. J Thorac Cardiovasc Surgery. 2004;128(4);502-508. https://www.jtcvs.org/article/S0022-5223(04)00772-X/fulltext.
  6. Haga, T., Kurihara, M., Kataoka, H., etal. Clinical-Pathological Findings of Catamenial Pneumothorax: Comparison Between Recurrent Cases and Non-Recurrent Cases. Ann Thorac. 2014;202(6);202-206. https://www.jstage.jst.go.jp/article/atcs/20/3/20_oa.12.02227/_article.
  7. Leong, A. C., Coonar, A. S., Lang-Lazdunski, L. L. Catamenial Pneumothorax: Surgical Repair of the Diaphragm and Hormone Treatment. Ann R Coll Surg Engl. 2006;88(6). https://publishing.rcseng.ac.uk/doi/10.1308/003588406X130732.
  8. Marjański, T., Sowa, K., Czapla, A., etal. Catamenial Pneumothorax – A Review of the Literature. Polish Journal of Thoracic and Cardiovascular Surgery. 2016;13(2);117-121. https://www.termedia.pl/Catamenial-pneumothorax-a-review-of-the-literature,40,27920,0,1.html.
  9. Bagan, P., Le Pimpec Barthes, F., Assouad, J, etal. Catamenial Pneumothorax: Retrospective Study of Surgical Treatment. Ann Thorac. 2022;75(22);378-381. https://www.annalsthoracicsurgery.org/article/S0003-4975(02)04320-5/fulltext.
  10. Herzog, Andrew. Catamenial Epilepsy: Definition, Prevalence, Pathophysiology and Treatment. Elsevier Sci. 2008;17;151-159. https://pubmed-ncbi-nlm-nih-gov.lmunet.idm.oclc.org/18164632/.

 

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, Massachusetts General Hospital, Harvard Catalyst, Harvard University, their 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 Does My Young Female Patient Have Recurrent Spontaneous Pneumothoraces?

Is there a connection between nocturia and obstructive sleep apnea (OSA)?

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

Absolutely! Although seemingly unrelated medical conditions, nocturia is commonly associated with OSA. [1,2]

A retrospective study [1] (n = 138) reported pathologic nocturia (≥2 urination events per night) in 47.8% of patients with OSA-hypopnea-syndrome. In this study, nocturia was linked to increasing age, 02 desaturation and severity of OSA. In another study (n=30), OSA (defined as apnea-hypopnea index [AHI] ≥5) was diagnosed in 66% of patients with nocturia with increasing nocturia associated with higher AHI.[2]

Recall that repetitive apnea episodes in OSA expose cardiovascular system to cycles of exaggerated negative intrathoracic pressure. [3] This causes myocardial stretching which is likely the reason OSA has been linked to elevated nocturnal atrial natriuretic peptide (ANP) levels. [4] In turn, ANP as an aldosterone inhibitor, increases salt and water excretion causing nocturia. Of interest, use of continuous positive airway pressure (CPAP) has been shown to normalize ANP levels [5] which may explain CPAP’s favorable impact on the frequency of nocturia based on a meta-analysis. [6]

Although the role of screening for OSA in nocturia remains unclear, OSA should be considered in the differential diagnosis of nocturia, especially in men and women younger than 50 years of age. [7,8]

Bonus pearl: Did you know that OSA has been associated with recreational MDMA (“ecstasy”) use, with severity of OSA correlating with lifetime MDMA exposure? [9]

Contributed by Fahad Tahir, MD, Mercy Hospital-St. Louis, St. Louis, Missouri

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References:

  1. Hajduk IA, Strollo PJ Jr, Jasani RR, Atwood CW Jr, Houck PR, Sanders MH. Prevalence and predictors of nocturia in obstructive sleep apnea-hypopnea syndrome–a retrospective study. Sleep. 2003 Feb 1;26(1):61-4. PMID: 12627734. https://pubmed.ncbi.nlm.nih.gov/12627734/
  2. Umlauf MG, Chasens ER, Greevy RA, Arnold J, Burgio KL, Pillion DJ. Obstructive sleep apnea, nocturia and polyuria in older adults. Sleep. 2004 Feb 1;27(1):139-44. doi: 10.1093/sleep/27.1.139. PMID: 14998251.https://pubmed.ncbi.nlm.nih.gov/14998251/
  3. Bradley TD, Floras JS. Obstructive sleep apnoea and its cardiovascular consequences. Lancet. 2009 Jan 3;373(9657):82-93. doi: 10.1016/S0140-6736(08)61622-0. Epub 2008 Dec 26. PMID: 19101028. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(08)61622-0/fulltext
  4. Svatikova A, Shamsuzzaman AS, Wolk R, Phillips BG, Olson LJ, Somers VK. Plasma brain natriuretic peptide in obstructive sleep apnea. Am J Cardiol. 2004 Aug 15;94(4):529-32. doi: 10.1016/j.amjcard.2004.05.010. PMID: 15325948. https://www.ajconline.org/article/S0002-9149(04)00730-1/fulltext/
  5. Krieger J, Laks L, Wilcox I, Grunstein RR, Costas LJ, McDougall JG, Sullivan CE. Atrial natriuretic peptide release during sleep in patients with obstructive sleep apnea before and during treatment with nasal continuous positive airway pressure. Clin Sci (Lond). 1989 Oct;77(4):407-11. doi: 10.1042/cs0770407. PMID: 2530023. https://pubmed.ncbi.nlm.nih.gov/2530023/
  6. Wang T, Huang W, Zong H, Zhang Y. The Efficacy of Continuous Positive Airway Pressure Therapy on Nocturia in Patients With Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis. Int Neurourol J. 2015 Sep;19(3):178-84. doi: 10.5213/inj.2015.19.3.178. Epub 2015 Sep 22. PMID: 26620900; PMCID: PMC4582090. https://pubmed.ncbi.nlm.nih.gov/26620900/
  7. Lowenstein L, Kenton K, Brubaker L, Pillar G, Undevia N, Mueller ER, FitzGerald MP. The relationship between obstructive sleep apnea, nocturia, and daytime overactive bladder syndrome in women. Am J Obstet Gynecol. 2008 May;198(5):598.e1-5. doi: 10.1016/j.ajog.2008.02.024. PMID: 18455544. https://www.ajog.org/article/S0002-9378(08)00168-3/fulltext
  8. Moriyama Y, Miwa K, Tanaka H, Fujihiro S, Nishino Y, Deguchi T. Nocturia in men less than 50 years of age may be associated with obstructive sleep apnea syndrome. Urology. 2008 Jun;71(6):1096-8. doi: 10.1016/j.urology.2008.02.038. Epub 2008 Apr 8. PMID: 18400277.https://pubmed.ncbi.nlm.nih.gov/18400277/
  9. McCann UD, Sgambati FP, Schwartz AR, Ricaurte GA. Sleep apnea in young abstinent recreational MDMA (“ecstasy”) consumers. Neurology. 2009 Dec 8;73(23):2011-7. doi: 10.1212/WNL.0b013e3181c51a62. Epub 2009 Dec 2. PMID: 19955499; PMCID: PMC2790228. https://n.neurology.org/content/73/23/2011.long

 

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, Massachusetts General Hospital, Harvard Catalyst, Harvard University, their 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!

 

 

 

Is there a connection between nocturia and obstructive sleep apnea (OSA)?

What’s the connection between traumatic rib fractures and pulmonary embolism?

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

Pulmonary embolism (PE) may be a complication of traumatic rib fractures but not necessarily associated with the number of ribs involved.1,2 PE or venous thromboembolism (VTE) is likely related at least in part to the hypercoagulable state that often follows traumatic injury.3

Diagnosis of PE may be challenging because chest pain and shortness of breath attributed to rib fractures can also be a manifestation of PE. Nevertheless, we should consider PE in any patient with chest pain following rib fracture who has hypoxemia or has other risk factors for this complication (eg, obesity, hospitalization, malignancy, history of prior VTE, postoperative state, estrogen use, heart failure, COPD).4 In a retrospective study of 548 patients with traumatic rib fracture, 1.1% were diagnosed with PE.1 The true incidence of PE in patients with rib fracture is unclear, however.

Hypercoagulability following rib fracture likely contributes to the risk of PE. A prospective cohort study of patients admitted to ICU following trauma (97% blunt), found a high prevalence of hypercoagulability (62% on day 1 and 26% on day 4) based on thrombelastography analysis. Women were more hypercoagulable than men early after injury.  Among those classified as hypercoagulable, 10% developed VTE.3

Bonus Pearl: Did you know that in patients with blunt chest trauma, age >65 y and 3 or more rib fractures are associated with increased risk of mortality?

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References

  1. Sirmali M, Turut H, Topcu S, et al. A comprehensive analysis of traumatic rib fractures: morbidity, mortality and management. Eur J Cardio-Thoracic Surg 2003;24:133-138.
  2. Flagel BT, Luchette FA, Reed R, et al. Half-a-dozen ribs: The breakpoint for mortality. Surgery 2005;138:717-25.
  3. Schreiber MA, Differding J, Thorborg P, et al. Hypercoagulability is most prevalent early after injury and in female patients. J Trauma 2005;58:475-81.
  4. Belohlavek J, Vytrych V, Linhart A. Pulmonary embolism, part I: Epidemiology, risk factors and risk stratification, pathophysiology, clinical presentation, diagnosis and nonthrombotic pulmonary embolism. Exp Clin Cardiol 2013;18:129-138.
  5. Battle CE, Hutchings H, Evans PA. Risk factors that predict mortality in patients with blunt chest wall trauma: A systematic review and meta-analysis. Injury 2012;43:8-17. 

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, Massachusetts General Hospital, Harvard Catalyst, Harvard University, their 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’s the connection between traumatic rib fractures and pulmonary embolism?

Why is Covid-19 more contagious than SARS or MERS?

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

From the beginning of the Covid-19 pandemic, it was evident that SARS-CoV2, the agent of Covid-19, was more contagious than other well-known coronaviruses that cause SARS or MERS. Based on a fascinating “shell disorder” model, the reason may lie in the “odd” combination of “hardiness” of its membrane protein (M) (outer shell) making it more likely to survive in body fluids and environment, and resilience of its nuclear protein (N) (inner shell) making it more likely to rapidly replicate even before the immune system detects it.1

Outer shell hardiness of the M protein of SARS-CoV2 contributes to its persistence in the environment and resistance to digestive enzymes in saliva, mucus, stool, and other bodily fluids. Inner shell resilience of the N protein can lead to greater virulence through more rapid replication of viral proteins and particles. The latter is also an efficient way of evading the host immune system ie, by the time the immune system finds out there is a problem, the virus has already reproduced in high numbers in the absence of symptoms!

Long before Covid-19 pandemic, a group of scientists proposed categorization of coronaviruses into 3 major “shell disorder” categories (based on the features of the M and N proteins), correlating with their primary modes of transmission. Category A: higher levels of respiratory transmission, lower levels of fecal-oral transmission (eg. HCoV-229E, common cold coronavirus); category B: intermediate levels of respiratory and fecal-oral transmission (eg, SARS-CoV); and category C: lower levels of respiratory transmission with higher levels of fecal-oral transmission (eg, MERS).1,2  

It turns out that Covid-19 falls into category B which means that it has the potential for transmission not only through respiratory route but also through fecal-oral route and the environment. What’s “odd” about SARS-CoV2 though is that it seems to have the hardiest outer shell compared to SARS-CoV and other coronaviruses in its category.

So not only is Covid-19 more likely to be transmitted due to high viral loads in the respiratory tract even before symptoms develop, it may have an advantage over other respiratory coronaviruses by persisting in the environment when contaminated by respiratory secretions, feces or other body fluids.

Truly a “novel” virus!

Bonus Pearl: Did you know that despite being more contagious, Covid-19 is fortunately less fatal than SARS or MERS?

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References

  1. Goh GKM, Dunker AK, Foster JA, Uversy VN. Shell disorder analysis predicts greater resilience of the SARS-CoV-2 (COVID-19) outside the body and in body fluids. Microbial pathogenesis 2020;144:104177. https://pubmed.ncbi.nlm.nih.gov/32244041/
  2. Goh GKM, Dunker AK, Uversky VN. Understanding viral transmission behavior via protein intrinsic disorder prediction: Coronaviruses. J Pathol 2012;2012:738590. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3477565/

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 is Covid-19 more contagious than SARS or MERS?

My 75 year old patient has an arterial oxygen tension (Pa02) less than 90 mmHg on room air. Does age affect PaO2?

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

Short answer: Yes! Most studies of blood gas concentrations have demonstrated a decrease in oxygen tension with age.1

Earlier studies have demonstrated a linear decrease in oxygen tension based on observations that included relatively small number of patients over the age of 60. 1 More recently, however, in a study of 532 consecutive patients admitted for elective surgery without overt cardiac, pulmonary, or metabolic disease, obesity or smoking, the mean PaO2 differed by age group as follows:

  • <30 years: 98.4 mmHg
  • 30-50 years: 88.7 mmHg
  • 51-70 years: 81.0 mmHg
  • >70 years: 76.5 mmHg

After age 70 years, decline in Pa02 may slow down or actually reverse, likely related to the “survival of the fittest” in more advanced years. 1,2 Some have suggested accepting a PaO2 80-85 mmHg as normal for subjects > 65 years of age. 3

The decrease in PaO2 with age is a result of increased heterogeneity of ventilation/perfusion ratio, especially reduced ventilation in the dependent parts of the lung. 3 Aging is also associated with a decrease in chest wall compliance, muscle (including the diaphragm) strength, forced expiratory volume in 1 second (FEV1), vital capacity, and diffusing capacity of carbon monoxide (DLC0)/alveolar volume.  

In addition, aging is associated with a reduction in response to hypoxia and hypercarbia, making older patients particularly vulnerable to complications from  heart failure and pneumonia4, especially in the current Covid-19 era.

Bonus Pearl: Did you know that poor response to hypoxic or hypercarbic states in the elderly is likely related to an age-related decline in efferent neural output to respiratory muscles?4

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References

  1. Blom H, Mulder M, Verwej W. Arterial oxygen tension and saturation in hospital patients: effect of age and activity. BMJ 1988;297:720-2. Doi:10.1136/bmj.297.6650.720 https://www.bmj.com/content/297/6650/720   
  2. Delclaux B, Orcel B, Housset B, et al. Arterial blood gases in elderly persons with chronic obstructive pulmonary disease (COPD). Eur Respir J 1994;7:856-61. https://www.researchgate.net/publication/15147788_Arterial_blood_gases_in_elderly_persons_with_chronic_obstructive_pulmonary_disease_COPD
  3. Janssens JP, Pache JC, Nicod LP. Physiological changes in respiratory function associated with ageing. Eur Respir J 1999;13:197-205. https://www.researchgate.net/publication/12689073_Physiological_changes_in_respiratory_function_associated_with_ageing
  4. Sharma G, Goodwin J. Effect of aging on respiratory system physiology and immunology. Clin Interventions in Aging 2006;1:253-60. https://pubmed.ncbi.nlm.nih.gov/18046878/

 

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!

 

 

My 75 year old patient has an arterial oxygen tension (Pa02) less than 90 mmHg on room air. Does age affect PaO2?

What is the role of prone ventilation in patients with Covid-19 and ARDS?

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

A 2017 guideline strongly recommends the use of prone ventilation for 12+ hours daily in individuals with severe ARDS (1). A JAMA article gave similar recommendations for critically ill patients with COVID-19 (2).

The recommendations are often based on a NEJM 2013 randomized-controlled study involving 466 patients with severe ARDS (3). While previous research had demonstrated improved oxygenation in the prone position (4), this study demonstrated a significant survival benefit (3).  Mortality at 28 days was 16.0% in prone patients versus 32.8% in supine patients (p<0.001; HR 0.39 with 95% CI, 0.29 – 0.67) (3). Mortality was also lower in prone patients at 90 days (3).  A meta-analysis of 4 additional randomized-controlled trials confirmed the survival benefits (1). 

In patients with Covid-19 and ARDS, a small retrospective study involving 12 patients showed a significant association between prone positioning and lung recruitability (ie, lung tissue in which aeration can be restored) (p = 0.020) (5).

Physiologically, numerous mechanisms have been proposed for these findings, including the possbility that while blood flow consistently favors the dorsal alveoli regardless of position, the prone position allows dorsal alveoli to reopen, improving ventilation/perfusion matching (6). 

Of note, some institutions find difficulties with prone positioning, including higher rates of pressure sores and endotracheal tube obstruction (1).

 

Contributed by Grant Steele, Harvard Medical Student, Boston, MA.

 

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References:

1. Fan E, Del Sorbo L, Goligher E, et al. An official American Thoracic Society/European Society of Intensive Care Medicine/Society of Critical Care Medicine clinical practice guideline: mechanical ventilation in adult patients with acute respiratory distress syndrome.” Am J Respir Crit Care Med 2017;195:1253-1263. https://www.atsjournals.org/doi/abs/10.1164/rccm.201703-0548ST 
2. Murthy S, Gomersall C, & Fowler R. Care for critically ill patients with COVID-19. JAMA – Published online March 11, 2020. doi:10.1001/jama.2020.3633 https://jamanetwork.com/journals/jama/fullarticle/2762996
3. Guérin C, Reignier J, Richard J-C, et al. Prone positioning in severe acute respiratory distress syndrome. N Engl J Med 2013;368:2159-2168. https://www.nejm.org/doi/full/10.1056/nejmoa1214103
4. Abroug F, Ouanes-Besbes L, Elatrous S, et al. The effect of prone positioning in acute respiratory distress syndrome or acute lung injury: a meta-analysis. Areas of uncertainty and recommendations for research. Intensive Care Medicine – Published online March 19, 2008. doi: 10.1007/s00134-008-1062-3 https://link.springer.com/article/10.1007/s00134-008-1062-3
5. Pan C, Chen L, Lu C, et al. Lung Recruitability in SARS-CoV-2 Associated Acute Respiratory Distress Syndrome: A Single-center, Observational Study. Am J Respir Crit Care Med – Published online March 23, 2020. doi: 10.1164/rccm.202003-0527LE. https://www.atsjournals.org/doi/pdf/10.1164/rccm.202003-0527LE 
6. Nyrén S, Mure M, Jacobsson H, et al. Pulmonary perfusion is more uniform in the prone than in the supine position: scintigraphy in healthy humans. J Appl Physiol 1999;86:1135-1141. https://www.physiology.org/doi/abs/10.1152/jappl.1999.86.4.1135

 

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 is the role of prone ventilation in patients with Covid-19 and ARDS?

Should I continue or discontinue angiotensin converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) in my patients with possible Coronavirus/Covid-19 infection?

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

The original reports of an association between hypertension and increased risk of mortality in hospitalized patients with Covid-19 infection raised concern over the potential deleterious role of ACEIs or ARBs in such patients.1-4 However, as stated by a joint statement of several cardiology societies, including the American Heart Association, American College of Cardiology and the European Society of Cardiology on March 13, 2020, there is no clinical or scientific evidence that ACEI or ARBS should be routinely discontinued in patients with Covid-19 infection.5

In fact, some have argued for the opposite ie, consideration for the use of ARBs, such as losartan (an angiotensin receptor 1 [AT1R] antagonist), in patients with Covid-19.6,7  Although it is true that Covid-19 appears to use ACE2 as a binding site to infect cells (just as in SARS) and that ACE2 may be upregulated in patients on chronic ACEI or ARBs,8,9 ACE2 may also potentially protect against severe lung injury associated with infections.10,11  

Two complementary mechanisms have been posited for the potential protective effect of ARBs in Covid-19 infection-related lung injury: 1. Blocking the excessive AT1R activation caused by the viral infection; and 2. Upregulation of ACE2, thereby reducing production of angiotensin II and increasing the production of the vasodilator angiotensin 1-7.7

In the absence of proper clinical studies, it is premature, however, to recommend use of losartan or other AT1R antagonists as a means of reducing the likelihood of ARDS in patients with Covid-19 at this time.

Bonus Pearl: Did you know that ARDS is a major cause of death in Covid-19 infection?12

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References

  1. Guan W, Ni Z, Hu Y, et al. Clinical characteristics of coronavirus disease 2019 in China. N Engl J Med 2020, March 6. https://www.nejm.org/doi/pdf/10.1056/NEJMoa2002032?articleTools=true
  2. O’Mara GJ. Could ACE inhibitors, and particularly ARBs, increase susceptibility to COVID-19 infection? BMJ 2020;368:m406 ARTICLE
  3. Sommerstein R, Grani C. Preventing a Covid-19 pandemic: ACE inhibitors as a potential risk factor for fatal Covid-19. BMJ2020;368:m810. https://www.bmj.com/content/368/bmj.m810/rr-2
  4. Li X, Geng M, Peng Y, et al. Molecular immune pathogenesis and diagnosis of COVID-19. Journal of Pharmaceutical Analysis 2020, doi htps://doi.org/10.106/j.jpha.2020.03.001. https://www.sciencedirect.com/science/article/pii/S2095177920302045
  5. Cardiology societies recommend patients taking ACE inhibitors, ARBs who contract COVID-19 should continue treatment. March 17, 2020. https://www.healio.com/cardiology/vascular-medicine/news/online/%7Bfe7f0842-aecb-417b-9ecf-3fe7e0ddd991%7D/cardiology-societies-recommend-patients-taking-ace-inhibitors-arbs-who-contract-covid-19-should-continue-treatment
  6. Gurwitz D. Angiotensin receptor blockers as tentative SARS-CoV-2 therapeutics. Drug Dev Res 2020;1-4. https://www.ncbi.nlm.nih.gov/pubmed/32129518/
  7. Phadke M, Saunik S. Response to the emerging novel coronavirus outbreak. BMJ 2020;368:m406. https://www.bmj.com/content/368/bmj.m406/rr-2
  8. Zheng YY, Ma YT, Zhang JY, et al. COVID-19 and the cardiovascular system. Nature Reviews/Cardiology 2020; https://doi.org/10.1038/s41569-020-0360-5 .
  9. Ferrario CM, Jessup J, Chappell MC, et al. Effect of angiotensin-converting enzyme inhibition and angiotensin II receptor blockers on cardiac angiotensin-converting enzyme 2. Circulation 2005;111:2605-2610. https://www.ahajournals.org/doi/full/10.1161/circulationaha.104.510461
  10. Kuba K, Imai Y, Rao S, et al. A crucial role of angiotensin converting enzyme 2 (ACE2) in SARS coronavirus-induced lung injury. Nature Medicine 2005;11:875-79. Doi:10.1038/nm1267 https://www.nature.com/articles/nm1267?v=1
  11. Tikellis C, Thomas MC. Angiotensin-converting enzyme 2 (ACE2) is a key modulator of the renin angiotensin system in health and disease. International Journal of Peptides. Volume 2012, Article ID 256294, 8 pages. Doi:10.1155/2012/256294. https://research.monash.edu/en/publications/angiotensin-converting-enzyme-2-ace2-is-a-key-modulator-of-the-re

12 . Huang C, Wang Y, Li X, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 2020. https://doi.org/10.1016/S0140-6736(20)30183-5

 

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!

Should I continue or discontinue angiotensin converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) in my patients with possible Coronavirus/Covid-19 infection?

When should I consider a switch to oral antibiotics and discharge from hospital in my recently admitted elderly patient with community-acquired pneumonia (CAP)?

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

A frequently used validated set of clinical stability criteria in patients with CAP and supported by the 2019 ATS/IDSA CAP guidelines consists of a temperature ≤37.8 ᵒC (100.0 ᵒF) AND no more than 1 CAP-related sign of clinical instability as listed below: 1-3

  • Heart rate >100/min
  • Systolic blood pressure <90 mm Hg
  • Respiration rate >24 breaths/min
  • Arterial oxygen saturation <90% or Pa02<60 mm Hg (room air)

Using these criteria, the risk of clinical deterioration serious enough to necessitate transfer to an intensive care unit may be 1% or less, 1 while failure to achieve clinical stability within 5 days is associated with higher mortality and worse clinical outcome. 2 The median time to clinical stability (as defined) for CAP treatment is 3 days.1  

A 2016 randomized-controlled trial involving patients hospitalized with CAP found that implementation of above clinical stability criteria was associated with safe discontinuation of antibiotics after a minimum of 5 days of appropriate therapy. 3 

Potential limitations of the above study include heavy use of quinolones (80%), underrepresentation of patients with severe CAP (Pneumonia Risk Index, PSI, V), and exclusion of nursing home residents, immunosuppressed patients, those with chest tube, or infection caused by less common organisms, such as Staphylococcus aureus or Pseudomonas aeruginosa.

Lack of clinical stability after 5 days of CAP treatment should prompt evaluation for complications of pneumonia (eg, empyema, lung abscess), infection due to  organisms resistant to selected antibiotics, or an alternative source of infection/inflammatory/poor response. 2

References

  1. Halm, EA, Fine MJ, Marrie TJ, et al. Time to clinical stability in patients hospitalized with community-acquired pneumonia: implications for practice guidelines. JAMA 1998;279:279:1452-57. https://reference.medscape.com/medline/abstract/9600479
  2. Metlay JP, Waterer GW, Long AC, et al. Diagnosis and treatment of adults with community-acquired pneumonia. Am J Respir Crit Care Med 2019;200:e45-e67. https://www.ncbi.nlm.nih.gov/pubmed/31573350
  3. Uranga A, Espana PP, Bilbao A, et al. Duration of antibiotic treatment in community-acquired pneumonia. A multicenter randomized clinical trial. JAMA Intern Med 2016;176:1257-65. https://www.ncbi.nlm.nih.gov/pubmed/27455166/
When should I consider a switch to oral antibiotics and discharge from hospital in my recently admitted elderly patient with community-acquired pneumonia (CAP)?

What changes should I consider in my treatment of hospitalized patients with community-acquired pneumonia (CAP) in light of the 2019 guidelines of the American Thoracic society (ATS) and Infectious Diseases Society of America (IDSA)?

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

Compared to 2007,1 the 2019 ATS/IDSA guidelines2 propose changes in at least 4 major areas of CAP treatment in inpatients, with 2 “Do’s” and 2 “Dont’s”:

  • Do select empiric antibiotics based on severity of CAP and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (see related pearl on P4P)
  • Do routinely treat CAP patients who test positive for influenza with standard CAP antibiotics
  • Don’t routinely provide anaerobic coverage in aspiration pneumonia (limit it to empyema and lung abscess) (see related pearl on P4P)
  • Don’t routinely treat CAP with adjunctive corticosteroids in the absence of refractory shock

β-lactam plus macrolide is recommended for both non-severe and severe CAP.  β-lactam plus respiratory fluoroquinolone is an alternative regime in severe CAP, though not endorsed as strongly as β-lactam plus macrolide therapy (low quality of evidence).  Management per CAP severity summarized below:

  • Non-severe CAP
    • β-lactam (eg, ceftriaxone, cefotaxime, ampicillin-sulbactam and newly-added ceftaroline) plus macrolide (eg, azithromycin, clarithromycin) OR respiratory fluoroquinolone (eg, levofloxacin, moxifloxacin)
    • In patients at risk of MRSA or P. aeruginosa infection (eg, prior isolation of respective pathogens, hospitalization and parenteral antibiotics in the last 90 days or locally validated risk factors—HCAP has been retired), obtain cultures/PCR
    • Hold off on MRSA or P. aeruginosa coverage unless culture/PCR results return positive.
  • Severe CAP
    • β-lactam plus macrolide OR β-lactam plus respiratory fluoroquinolone (see above)
    • In patients at risk of MRSA or P. aeruginosa infection (see above), obtain cultures/PCR
    • Add MRSA coverage (eg, vancomycin or linezolid) and/or P. aeruginosa coverage (eg, cefepime, ceftazidime, piperacillin-tazobactam, meropenem, imipenem) if deemed at risk (see above) while waiting for culture/PCR results

Duration of antibiotics is for a minimum of 5 days for commonly-targeted pathogens and a minimum of 7 days for MRSA or P. aeruginosa infections, irrespective of severity or rapidity in achieving clinical stability.

For patients who test positive for influenza and have CAP, standard antibacterial regimen should be routinely added to antiinfluenza treatment.

For patients suspected of aspiration pneumonia, anaerobic coverage (eg, clindamycin, ampicillin-sulbactam, piperacillin-tazobactam) is NOT routinely recommended in the absence of lung abscess or empyema.

Corticosteroids are NOT routinely recommended for non-severe (high quality of evidence) or severe (moderate quality of evidence) CAP in the absence of refractory septic shock.

Related pearls on P4P:

2019 CAP guidelines on diagnostics:                                        https://pearls4peers.com/2020/02/14/what-changes-should-i-consider-in-my-diagnostic-approach-to-hospitalized-patients-with-community-acquired-pneumonia-cap-in-light-of-the-2019-guidelines-of-the-american-thoracic-society-ats-and-inf/ 

Anerobic coverage of aspiration pneumonia: https://pearls4peers.com/2019/07/31/should-i-routinely-select-antibiotics-with-activity-against-anaerobes-in-my-patients-with-presumed-aspiration-pneumonia/

References

  1. Mandell LA, Wunderink RG, Anzueto A. Infectious Disease Society of America/American Thoracic Society Consensus Guidelines on the Management guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis 2007;44:S27-72. https://www.ncbi.nlm.nih.gov/pubmed/17278083
  2. Metlay JP, Waterer GW, Long AC, et al. Diagnosis and treatment of adults with community-acquired pneumonia. Am J Respir Crit Care Med 2019;200:e45-e67. https://www.ncbi.nlm.nih.gov/pubmed/31573350

 

What changes should I consider in my treatment of hospitalized patients with community-acquired pneumonia (CAP) in light of the 2019 guidelines of the American Thoracic society (ATS) and Infectious Diseases Society of America (IDSA)?

What changes should I consider in my diagnostic approach to hospitalized patients with community-acquired pneumonia (CAP) in light of the 2019 guidelines of the American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA)?

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

Compared to 2007,1 the 2019 ATS/IDSA guidelines2 have 2 major “Do’s” and 2 major “Dont’s” in the diagnostic approach to CAP in hospitalized patients:

  • DO order sputum and blood cultures in patients empirically treated for methicillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa—in addition to those with severe CAP as in 2007.  
  • DO order rapid influenza molecular assay—in preference to antigen test— when influenza viruses are circulating in community, irrespective of pneumonia severity
  • DON’T routinely order urine antigens for pneumococcal or Legionella antigens, except in severe CAP or in the presence of suggestive epidemiological factors (eg. Legionella outbreak, recent travel)
  • DON’t routinely order serum procalcitonin to determine need for initial antibacterial therapy

Patients at risk of MRSA or P. aeruginosa include those with prior infection with the same pathogens as well as those with hospitalization and treated with parenteral antibiotics—in or out of the hospital— in the last 90 days; HCAP is no longer recognized as an entity.

The definition of severe CAP is unchanged: 1 of 2 major criteria (septic shock or respiratory failure requiring mechanical ventilation) or 3 or more of the following minor criteria or findings listed below:

  • Clinical
    • Respiratory rate ≥30 breath/min
    • Hypotension requiring aggressive fluid resuscitation
    • Hypothermia (core temperature <36 ᵒC, 96.8 ᵒF)
    • Confusion/disorientation
  • Radiographic 
    • Multilobar infiltrates
  • Laboratory 
    • Leukopenia (WBC <4,000/ul)
    • Thrombocytopenia (platelets <100,000/ul)
    • BUN ≥20 mg/dl
    • Pa02/FI02 ratio ≤250

Keep in mind that these guidelines focus on adults who are not immunocompromised or had recent foreign travel and are often based on expert opinion but low or very low quality evidence due to the dearth of properly designed studies.2 

Bonus Pearl: Did you know that the urine Legionella antigen only tests for L. pneumophila type I, with an overall sensitivity ranging from 45% to 100%!3,4

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References

  1. Mandell LA, Wunderink RG, Anzueto A. Infectious Disease Society of America/American Thoracic Society Consensus Guidelines on the Management guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis 2007;44:S27-72. https://www.ncbi.nlm.nih.gov/pubmed/17278083
  2. Metlay JP, Waterer GW, Long AC, et al. Diagnosis and treatment of adults with community-acquired pneumonia. Am J Respir Crit Care Med 2019;200:e45-e67. https://www.ncbi.nlm.nih.gov/pubmed/31573350
  3. Blazquez RM, Espinosa FJ, Martinez-Toldos CM, et al. Sensitivity of urinary antigen test in relation to clinical severity in a large outbreak of Legionella pneumonia in Spain. Eur J Clin Microbiol Infect Dis 2005;24:488-91. https://www.ncbi.nlm.nih.gov/pubmed/15997369
  4. Marlow E, Whelan C. Legionella pneumonia and use of the Legionella urinary antigen test. J Hosp Med 2009;4:E1-E2. https://www.ncbi.nlm.nih.gov/pubmed/19301376

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!

 

 

What changes should I consider in my diagnostic approach to hospitalized patients with community-acquired pneumonia (CAP) in light of the 2019 guidelines of the American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA)?