Podcast # 474: Obesity Hypoventilation Syndrome

Author: Peter Bakes, MD

Educational Pearls:

  • The differential diagnosis for pedal edema includes issues in the heart, kidney, and liver
  • Obesity hypoventilation syndrome (OHS) is an important and common cause of right heart failure. Nighttime hypoventilation leads to pulmonary hypertension, causing right heart strain followed by right heart failure
  • OHS criteria includes obesity, sleep disordered breathing, and alveolar hypoventilation (PaCO2 > 45 mmHg)
  • The causes of OHS are multifactorial, and include mechanical problems with breathing and hormonal changes

References

Balachandran JS, Masa JF, Mokhlesi B. Obesity Hypoventilation Syndrome Epidemiology and Diagnosis. Sleep Med Clin. 2014;9(3):341–347. doi:10.1016/j.jsmc.2014.05.007

Summarized by Will Dewispelaere, MS3 | Edited by Erik Verzemnieks, MD

Podcast # 461: Breath Stacking

Author: Gretchen Hinson, MD

Educational Pearls:

  • Breath stacking occurs when a patient is unable to expire fully before another inspiration
  • In intubated/ventilated patients, this is because adequate time has not passed before exhalation
  • Asthmatics are susceptible due to the prolonged expiratory phase
  • Complications can include reduction in cardiac preload and cardiovascular collapse
  • Pursed-lip breathing can help in the spontaneously breathing patient
  • Intubation may be required when patients present with status asthmaticus and breath stacking

References

Phipps P, Garrard CS. The pulmonary physician in critical care . 12: Acute severe asthma in the intensive care unit. Thorax. 2003 Jan;58(1):81-8. Review. PubMed PMID: 12511728; PubMed Central PMCID: PMC1746457.

Pohlman MC, McCallister KE, Schweickert WD, Pohlman AS, Nigos CP, Krishnan JA, Charbeneau JT, Gehlbach BK, Kress JP, Hall JB. Excessive tidal volume from breath stacking during lung-protective ventilation for acute lung injury. Crit Care Med. 2008 Nov;36(11):3019-23. doi: 10.1097/CCM.0b013e31818b308b. PubMed PMID: 18824913.

Summarized by Will Dewispelaere, MS3 | Edited by Erik Verzemnieks, MD

Podcast #445: Hunting for the endotracheal tube

Author: Michael Hunt, MD

Educational Pearls:

  • Bedside transtracheal ultrasound to confirm proper endotracheal intubation is simple and effective
  • Review of 17 studies showed transtracheal ultrasound was was 98.7% sensitive and 97.1% specific
  • Curvilinear probe may be preferable as it provides a larger field of view

Editor’s Note: rather than explain what you’re looking for… just go here

References:

Gottlieb M, Holladay D, Peksa GD. Ultrasonography for the Confirmation of Endotracheal Tube Intubation: A Systematic Review and Meta-Analysis. Ann Emerg Med. 2018 Dec;72(6):627-636. doi: 10.1016/j.annemergmed.2018.06.024. Epub 2018 Aug 14. PubMed PMID: 30119943.

Summarized and edited by Erik Verzemnieks, MD

Podcast #442: When a severe man cold isn’t

Author: Jared Scott, MD

Educational Pearls:

 

  • CXR is 40-90% sensitive for detecting pneumonia when compared to CT
  • Patients with a high degree of suspicion for pneumonia may still warrant treatment despite a negative CXR

 

References:

Self WH, Courtney DM, McNaughton CD, Wunderink RG, Kline JA. High discordance of chest x-ray and computed tomography for detection of pulmonary opacities in ED patients: implications for diagnosing pneumonia. Am J Emerg Med. 2013 Feb;31(2):401-5. doi: 10.1016/j.ajem.2012.08.041. Epub 2012 Oct 18. PubMed PMID: 23083885; PubMed Central PMCID: PMC3556231.

Summarized by Travis Barlock, MS4 | Edited by Erik Verzemnieks, MD

Podcast #401: Foreign Body Aspiration

Author: Gretchen Hinson, MD

Educational Pearls:

  • Diagnosis can be difficult and often delayed
  • Asymmetric breath sounds, choking, stridor may be present, but children also present asymptomatically
  • Peak incidence around one to two years of age
  • Hot dogs, nuts, popcorn – round and smooth objects are most commonly aspirated

References:

Green SS. Ingested and Aspirated Foreign Bodies. Pediatr Rev. 2015 Oct;36(10):430-6. doi: 10.1542/pir.36-10-430. Review. PubMed PMID: 26430203.

Sink JR, Kitsko DJ, Georg MW, Winger DG, Simons JP. Predictors of Foreign Body Aspiration in Children. Otolaryngol Head Neck Surg. 2016 Sep;155(3):501-7. doi: 10.1177/0194599816644410. Epub 2016 Apr 12. PubMed PMID: 27071446.

 

Summary by Travis Barlock, MS4  | Edited by Erik Verzemnieks, MD

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Podcast # 373: Legionnaires Disease

Author:  Gretchen Hinson, MD

Educational Pearls:

  • Legionnaires disease refers to a severe pneumonia caused by Legionella pneumophilia and occurs typically at the extremes of age
  • Associated gastrointestinal symptoms (nausea/vomiting/diarrhea) may be present
  • Hyponatremia is a common laboratory finding
  • Legionella urinary antigen can be a convenient test to identify the infection
  • Treatment is with fluoroquinolones, macrolides and/or tetracyclines

 

 

References

Pierre DM, Baron J, Yu VL, Stout JE. Diagnostic testing for Legionnaires’ disease. Annals of Clinical Microbiology and Antimicrobials. 2017;16:59. doi:10.1186/s12941-017-0229-6.

Cunha BA, Cunha CB. Legionnaire’s Disease and its Mimics: A Clinical Perspective. Infect Dis Clin North Am. 2017 Mar;31(1):95-109. doi: 10.1016/j.idc.2016.10.008. Review.

Podcast # 340: Drowning

Author: Chris Holmes, MD

Educational Pearls:

  • Epidemiology: 80% male, ages 1-4 at greatest risk, African-American > Caucasian.
  • Freshwater and ocean water may have more bacteria than pool water.
  • Salt water is hyperosmolar, which theoretically increases risk of pulmonary edema.
  • Greatest physiologic insult is from hypoxia secondary to fluid aspiration or laryngeal spasm. Patient survival is related to presentation on arrival.
  • Workup includes CXR and ABG; consider C-spine immobilization/imaging when cervical injury is strongly suspected (i.e. diving injury).
  • Treatment consists of supplemental oxygen therapy. Consider CPAP or intubation.

References

Szpilman D, Bierens JJ, Handley AJ, Orlowski JP. Drowning. N Engl J Med. 2012. 366(22):2102-10. doi: 10.1056/NEJMra1013317.

Schmidt A, Sempsrott J. Drowning In The Adult Population: Emergency Department Resuscitation And Treatment. Emerg Med Pract. 2015. 17(5):1-18.

Podcast # 337: Airway Burn Inhalation

Author: John Winkler, MD

Educational Pearls:

  • Singed nasal hairs, soot around mouth, hoarse voice, drooling, and burns to head/face are signs suggestive of inhalation injury.
  • Early intubation is critical for these patients as the airway changes rapidly.
  • With inhalation injuries, the upper airway is burned while the lower airway is damaged by inhaled chemicals in the soot and can cause ARDS.
  • Carbon monoxide (CO) and cyanide (CN) poisoning can occur with inhalation injuries.
  • Treatment for CO poisoning is 100% oxygen and possible hyperbarics. Treatment for CN poisoning is cyanocobalamin.

 

References

Rehberg S, Maybauer MO, Enkhbaatar P, et al. Pathophysiology, management and treatment of smoke inhalation injury. Expert Rev Respir Med 2009; 3:283.

Woodson CL. Diagnosis and treatment of inhalation injury. In: Total Burn Care, 4 ed, Herndon DN (Ed), 2009.

Podcast #325: Vaping and Pneumonia

Author: Sam Killian, MD

Educational Pearls:

  • Being exposed to E-cigarette vapor may increase risk of pneumonia.
  • Recent study has shown e-cigarette vapor increases quantities of Platelet-activating-receptor factor in epithelial cells, which may aid pneumococcal bacteria in entering pneumocytes.

References:

Miyashita L, et al. (2018). E-cigarette vapour enhances pneumococcal adherence to airway epithelial cells. The European Respiratory Journal. 7;51(2).

Podcast #320: PE in Pregnancy

Author: Don Stader, M.D.

Educational Pearls:

  • Pulmonary embolism is one of the leading causes of maternal mortality.
  • There is disagreement among different medical societies about the value of D-dimer as a screening modality. If you use it, consider the rational D-dimer approach whereby you add 250 to your cut-off for every trimester.
  • A useful screening modality is an ultrasound of bilateral lower extremities looking for DVT.
  • Keep in mind, both a V/Q scan and CT scan have a significant amount of radiation. CTA is probably the right diagnostic test (less radiation than CT w&w/o).
  • Always use the shared decision-making model and clinical acumen to choose your tests.

References:

Leung AN, et. al. (2011). An official American Thoracic Society/Society of Thoracic Radiology clinical practice guideline: evaluation of suspected pulmonary embolism in pregnancy. American Journal of Respiratory and Critical Care Medicine. 184(10):1200-8

 

Polak JF, Wilkinson DL. (1991). Ultrasonographic diagnosis of symptomatic deep venous thrombosis in pregnancy. American Journal of Obstetrics and Gynecology. 165(3):625-9.

Sachs BP, et. al. (1987). Maternal mortality in Massachusetts. Trends and prevention. New England Journal of Medicine. 316(11):667-72.

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