Hypoxia

Brief HPI:

A 67 year-old male with a history of hypertension and diabetes presents to the emergency department after a syncopal episode. He had been completing his normal morning routine when he developed a sensation of lightheadedness and awoke on the ground of his kitchen. He denies associated chest pain, palpitations, diaphoresis, or recent illness. He has no known sick contacts nor exposures to individuals undergoing evaluation for COVID-19.

On arrival in the emergency department, the patient was noted to be hypoxic with pulse oximetry measuring 74%. He was placed on supplemental oxygen via non-rebreather with improvement of oxygen saturation to 94%. Examination demonstrated diminished alertness (requiring constant stimulation for responses) and generalized motor weakness. Cardiac and pulmonary examinations were unremarkable with the exception of tachypnea and no extremity edema was appreciated.

A chest radiograph was obtained which demonstrated platelike atelectasis. An arterial blood gas was obtained with PaO2 of 72mmHg suggesting a prominent A-a gradient. CT pulmonary angiography was obtained:

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CT Pulmonary Angiography:

Bilateral pulmonary emboli. Case courtesy of Associate Prof Frank Gaillard, Radiopaedia.org, rID: 19636

Upon return, the patient’s mental status worsened associated with hypotension and he was intubated for airway protection and received systemic thrombolysis. He was subsequently taken for emergent endovascular treatment of massive pulmonary embolus.

An Algorithm for the Differential Diagnosis of Hypoxemia & Hypoxia1-7

Hypoxemia is defined as low PaO2 while hypoxia is insufficient global or local tissue oxygen content.

An Algorithm for the Differential Diagnosis of Hypoxemia and Hypoxia

References

  1. Stapczynski J. Respiratory Distress. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e New York, NY: McGraw-Hill; . http://accessmedicine.mhmedical.com/content.aspx?bookid=2353&sectionid=219642010. Accessed April 12, 2020.
  2. Gas Transport & pH. In: Barrett KE, Barman SM, Brooks HL, Yuan JJ. eds. Ganong’s Review of Medical Physiology, 26e New York, NY: McGraw-Hill; . http://accessmedicine.mhmedical.com/content.aspx?bookid=2525&sectionid=204297654. Accessed April 12, 2020.
  3. Loscalzo J. Hypoxia and Cyanosis. In: Jameson J, Fauci AS, Kasper DL, Hauser SL, Longo DL, Loscalzo J. eds. Harrison’s Principles of Internal Medicine, 20e New York, NY: McGraw-Hill; . http://accessmedicine.mhmedical.com/content.aspx?bookid=2129&sectionid=192012521. Accessed April 12, 2020.
  4. West NE, Lechtzin N. Chapter 93. Hypoxia. In: McKean SC, Ross JJ, Dressler DD, Brotman DJ, Ginsberg JS. eds. Principles and Practice of Hospital Medicine New York, NY: McGraw-Hill; 2012. http://accessmedicine.mhmedical.com/content.aspx?bookid=496&sectionid=41304065. Accessed April 12, 2020.
  5. Pulmonary Physiology. In: Kibble JD, Halsey CR. eds. Medical Physiology: The Big Picture New York, NY: McGraw-Hill; 2014. http://accessmedicine.mhmedical.com/content.aspx?bookid=1291&sectionid=75576764. Accessed April 12, 2020.
  6. Petersson, J., Glenny, R. (2014). Gas exchange and ventilation–perfusion relationships in the lung European Respiratory Journal 44(4), 1023-1041. https://dx.doi.org/10.1183/09031936.00037014
  7. Morchi, R. (2011). Diagnosis Deconstructed: The Case of the Patient with No Chief Complaint Emergency Medicine News XXXIII(3)
    Rodríguez-Roisin, R., Roca, J. (2005). Mechanisms of hypoxemia Intensive Care Medicine 31(8), 1017-1019. https://dx.doi.org/10.1007/s00134-005-2678-1

COVID-19

Brief HPI:

A 38 year-old male with a history of hypertension presents to the emergency department with fever, cough and shortness of breath. He notes 4 days of symptoms which have been gradually worsening despite over-the-counter treatments. He denies recent travel or sick contacts. While he attempted to remain isolated – his symptoms grew intolerable.

On arrival in the emergency department, vital signs were notable for tachycardia and hypoxia (SpO2 85%, improving to 92% on 4L by nasal cannula). Physical examination demonstrated tachypnea and accessory muscle use but clear lung fields, and no extremity edema nor jugular venous distension. A chest radiograph revealed patchy airspace opacities. A presumptive diagnosis of COVID-19 pneumonia was made.

While awaiting hospitalization, the patient’s hypoxia worsened though he remained otherwise alert and oriented. He was placed on 15L via non-rebreather and instructed regarding self-prone positioning. He was admitted to the intensive care unit.

An Algorithm for the Management of COVID-19 Hypoxic Respiratory Failure1-6

An algorithm for the management of COVID-19 respiratory failure

References

  1. Whittle, J., Pavlov, I., Sacchetti, A., Atwood, C., Rosenberg, M. (2020). Respiratory Support for Adult Patients with COVID‐19 Journal of the American College of Emergency Physicians Open https://dx.doi.org/10.1002/emp2.12071
  2. Hui, D., Chow, B., Chu, L., Ng, S., Lee, N., Gin, T., Chan, M. (2012). Exhaled Air Dispersion during Coughing with and without Wearing a Surgical or N95 Mask PLoS ONE  7(12), e50845. https://dx.doi.org/10.1371/journal.pone.0050845
  3. Hui, D., Chow, B., Lo, T., Ng, S., Ko, F., Gin, T., Chan, M. (2015). Exhaled Air Dispersion During Noninvasive Ventilation via Helmets and a Total Facemask Chest  147(5), 1336-1343. https://dx.doi.org/10.1378/chest.14-1934
  4. Hui, D., Chow, B., Lo, T., Tsang, O., Ko, F., Ng, S., Gin, T., Chan, M. (2019). Exhaled air dispersion during high-flow nasal cannula therapy versus CPAP via different masks European Respiratory Journal  53(4), 1802339. https://dx.doi.org/10.1183/13993003.02339-2018
  5. Sun, Q., Qiu, H., Huang, M., Yang, Y. (2020). Lower mortality of COVID-19 by early recognition and intervention: experience from Jiangsu Province Annals of Intensive Care  10(1), 33. https://dx.doi.org/10.1186/s13613-020-00650-2
  6. Roca, O., Caralt, B., Messika, J., Samper, M., Sztrymf, B., Hernández, G., García-de-Acilu, M., Frat, J., Masclans, J., Ricard, J. (2018). An Index Combining Respiratory Rate and Oxygenation to Predict Outcome of Nasal High-Flow Therapy American Journal of Respiratory and Critical Care Medicine  199(11), 1368-1376. https://dx.doi.org/10.1164/rccm.201803-0589oc

Pediatric Status Asthmaticus

Brief HPI:

A 6 year-old boy with a history of asthma presents to the emergency department via EMS for dyspnea. The patient is agitated on exam with nasal flaring and intercostal retractions. The parents report that his difficulty breathing started two days ago. The first day his MDI inhaler provided transient relief; however, over the next 24 hours he required nebulized albuterol 3 times with no significant relief. They deny any recent infections or steroid use and state that his immunizations are up-to-date.

On evaluation, vital signs are notable for BP 93/61, HR 140, RR 47, and SpO2 90%. He is afebrile; capillary glucose 113mg/dL. On examination, the patient is agitated with nasal flaring, intercostal retractions, shallow breathing with diminished breath sounds throughout.

Algorithm for the Management of Pediatric Asthma1-11

Algorithm for the Management of Pediatric Asthma

PASS12

Wheezing Work of Breathing Prolonged Expiration
Mild (0) None or end-expiration Normal or minimal retractions Normal or minimally prolonged
Moderate (1) Throughout expiration Intercostal retractions Moderately prolonged
Severe (2) Severe wheezing or absent Suprasternal retractions, abdominal wall movement Severely prolonged
This algorithm was developed by Dr. Joshua Niforatos. Joshua is an emergency medicine resident at The Johns Hopkins School of Medicine and an alumnus of the Cleveland Clinic Lerner College of Medicine.

Special thanks to Dr. Kelly Young, Director of the Pediatric Emergency Medicine Fellowship at Harbor-UCLA Medical Center and Dr. Adeola Kosoko, Assistant Professor, Assistant Residency Program Director, Director Of Diversity, Inclusion, And Mission at McGovern Medical School for their review of the algorithm.

References

  1. Rowe, B., Bretzlaff, J., Bourdon, C., Bota, G., Camargo, C. (2000). Magnesium sulfate for treating exacerbations of acute asthma in the emergency department. The Cochrane database of systematic reviews https://dx.doi.org/10.1002/14651858.cd001490
  2. Camargo, C., Spooner, C., Rowe, B. (2003). Continuous versus intermittent beta-agonists in the treatment of acute asthma. The Cochrane database of systematic reviews https://dx.doi.org/10.1002/14651858.cd001115
  3. Camargo, C., Rachelefsky, G., Schatz, M. (2009). Managing asthma exacerbations in the emergency department: summary of the National Asthma Education And Prevention Program Expert Panel Report 3 guidelines for the management of asthma exacerbations. Proceedings of the American Thoracic Society 6(4), 357 – 366. https://dx.doi.org/10.1513/pats.p09st2
  4. Gouin, S., Robidas, I., Gravel, J., Guimont, C., Chalut, D., Amre, D. (2010). Prospective evaluation of two clinical scores for acute asthma in children 18 months to 7 years of age. Academic emergency medicine : official journal of the Society for Academic Emergency Medicine 17(6), 598 – 603. https://dx.doi.org/10.1111/j.1553-2712.2010.00775.x
  5. Travers, A., Milan, S., Jones, A., Camargo, C., Rowe, B. (2012). Addition of intravenous beta(2)-agonists to inhaled beta(2)-agonists for acute asthma. The Cochrane database of systematic reviews 12(), CD010179. https://dx.doi.org/10.1002/14651858.cd010179
  6. Jat, K., Chawla, D. (2012). Ketamine for management of acute exacerbations of asthma in children. The Cochrane database of systematic reviews 11(), CD009293. https://dx.doi.org/10.1002/14651858.cd009293.pub2
  7. Ortiz-Alvarez, O., Mikrogianakis, A., Committee, C. (2012). Managing the paediatric patient with an acute asthma exacerbation. Paediatrics & child health 17(5), 251 – 262. https://dx.doi.org/10.1093/pch/17.5.251
  8. Jones, B., Paul, A. (2013). Management of acute asthma in the pediatric patient: an evidence-based review. Pediatric emergency medicine practice 10(5), 1 – 23- quiz 23-4.
  9. Nievas, I., Anand, K. (2013). Severe acute asthma exacerbation in children: a stepwise approach for escalating therapy in a pediatric intensive care unit. The journal of pediatric pharmacology and therapeutics : JPPT : the official journal of PPAG 18(2), 88 – 104. https://dx.doi.org/10.5863/1551-6776-18.2.88
  10. Rehder, K. (2017). Adjunct Therapies for Refractory Status Asthmaticus in Children. Respiratory care 62(6), 849 – 865. https://dx.doi.org/10.4187/respcare.05174
  11. Carroll, C., Sala, K. (2013). Pediatric status asthmaticus. Critical care clinics 29(2), 153 – 166. https://dx.doi.org/10.1016/j.ccc.2012.12.001
  12. Gorelick, M., Stevens, M., Schultz, T., Scribano, P. (2004). Performance of a novel clinical score, the Pediatric Asthma Severity Score (PASS), in the evaluation of acute asthma. Academic Emergency Medicine 11(1), 10 – 18. https://dx.doi.org/10.1197/s1069-6563(03)00579-7

Pleural Fluid

Brief HPI:

A 43 year-old female with no reported medical history presents with shortness of breath. She notes 2 months of gradually worsening symptoms associated with unproductive cough and intermittent subjective fevers. Symptoms are worsened with activity and when laying flat. She has no history of similar symptoms in the past.

Vital signs are notable for tachycardia, tachypnea and hypoxia. Examination demonstrates absent breath sounds in the entire right lung field. A plain chest radiograph is obtained and shown below. The patient was placed on non-invasive positive pressure with minimal improvement and an emergent therapeutic thoracentesis was performed. Pleural fluid was exudative and a large volume was submitted for cytology.

Whiteout right lung field Whiteout right lung field

An Algorithm for the Analysis of Pleural Fluid

An Algorithm for the Analysis of Pleural Fluid

References

  1. Light RW, Girard WM, Jenkinson SG, George RB. Parapneumonic effusions. Am J Med. 1980;69(4):507-512.
  2. Heffner JE, Brown LK, Barbieri CA. Diagnostic value of tests that discriminate between exudative and transudative pleural effusions. Primary Study Investigators. Chest. 1997;111(4):970-980. doi:10.1378/chest.111.4.970.
  3. Romero S, Martinez A, Hernandez L, et al. Light’s criteria revisited: consistency and comparison with new proposed alternative criteria for separating pleural transudates from exudates. Respiration. 2000;67(1):18-23. doi:10.1159/000029457.
  4. Light RW. Clinical practice. Pleural effusion. N Engl J Med. 2002;346(25):1971-1977. doi:10.1056/NEJMcp010731.
  5. Sahn SA, Huggins JT, San Jose E, Alvarez-Dobano JM, Valdes L. The Art of Pleural Fluid Analysis. Clinical Pulmonary Medicine. 2013;20(2):77-96. doi:10.1097/CPM.0b013e318285ba37.
  6. Light RW. The Light criteria: the beginning and why they are useful 40 years later. Clinics in Chest Medicine. 2013;34(1):21-26. doi:10.1016/j.ccm.2012.11.006.
  7. Aggarwal AN, Agarwal R, Sehgal IS, Dhooria S, Behera D. Meta-analysis of Indian studies evaluating adenosine deaminase for diagnosing tuberculous pleural effusion. Int J Tuberc Lung Dis. 2016;20(10):1386-1391. doi:10.5588/ijtld.16.0298.

Neonatal Congenital Heart Disease

Brief H&P

An 8-day old male infant, ex-full term, born by normal spontaneous vaginal delivery and discharged home 2 days after birth without identified complications or maternal infections presents with parents to the emergency department due to decreased activity. Starting on day-of-life six, the family noted that feeding appeared to be taking longer and the mother felt her infant was breathing faster.

On presentation, the patient was pale, dusky, lethargic and with mottled skin. Temperature 36.3°C (rectal), HR 170, RR 60, BP 62/35, SpO2 70%. Physical examination demonstrated flat fontanelle, coarse breath sounds, regular rate and rhythm without additional heart sounds or murmurs, and hepatomegaly with liver edge 3cm below costal margin. Capillary refill was delayed at 5-6 seconds. Supplemental oxygen was applied without effect.

Algorithm for the Evaluation and Management of Suspected Congenital Heart Disease in Neonates

Algorithm for the Evaluation of Neonatal Congenital Heart Disease

Neonates with undiagnosed congenital heart disease may present to the emergency department with nonspecific symptoms, and may be considerably unstable requiring immediate life-saving interventions.

Key Historical Features

  • Respiratory difficulty
  • Feeding difficulty (small quantities, diaphoresis during feeding)
  • Poor weight gain
  • Chromosomal abnormalities, syndromes
  • Maternal risk factors: diabetes, teratogen exposure, substance use
  • Sibling of affected child

Key Examination Findings

  • Vital signs: tachycardia, tachypnea, hypotension
  • Blood pressure differential (RUE vs. LE >8mmHg difference)
  • Pulse oximetry differential (RUE vs. LE >4% difference, <95%)
  • Cardiac examination: murmur, thrill, pulse differential, capillary refill, hepatomegaly

Workup

  • CXR: Evaluate for cardiomegaly, pulmonary vascular congestion
  • ECG: Evaluate for axis deviation (right axis deviation is normal for neonate)
  • ABG with co-oximetry

References

  1. Special thanks to Dr. Kelly Young, MD, MS, FAAP. Director, Pediatric Emergency Medicine Fellowship. Harbor-UCLA Medical Center Department of Emergency Medicine.
  2. Association AAOPAAH. Textbook of Neonatal Resuscitation. 2016.
  3. Lissauer T, Fanaroff AA, Miall L, Fanaroff J. Neonatology at a Glance. John Wiley & Sons; 2015.
  4. Steinhorn RH. Evaluation and Management of the Cyanotic Neonate. Clinical Pediatric Emergency Medicine. 2008;9(3):169-175. doi:10.1016/j.cpem.2008.06.006.
  5. MD MR. Chapter 7 – Cardiology. Twenty First Edition. Elsevier Inc.; 2018:156-202. doi:10.1016/B978-0-323-39955-5.00007-7.
  6. Gomella T, Cunningham M. Neonatology 7/E. McGraw-Hill Prof Med/Tech; 2013.
  7. Yee L. Cardiac emergencies in the first year of life. Emergency Medicine Clinics of NA. 2007;25(4):981–1008–vi. doi:10.1016/j.emc.2007.08.001.
  8. Yates MC, Rao PS. Pediatric cardiac emergencies. Emerg Med. 2013. doi:10.4172/2165-7548.1000164.
  9. Silberbach M, Hannon D. Presentation of congenital heart disease in the neonate and young infant. Pediatr Rev. 2007;28(4):123-131.
  10. Mastropietro CW, Tourner SP, Sarnaik AP. Emergency presentation of congenital heart disease in children. Pediatric Emergency …. 2008.
  11. Brousseau T, Sharieff GQ. Newborn Emergencies: The First 30 Days of Life. Pediatric Clinics of North America. 2006;53(1):69-84. doi:10.1016/j.pcl.2005.09.011.

Ultrasound in Dyspnea

Brief H&P:

A 68 year-old male with a history of hypertension, diabetes, hyperlipidemia, chronic obstructive pulmonary disease and congestive heart failure (CHF) with depressed ejection fraction presents via ambulance with a chief complaint of shortness of breath. EMS reports that the patient was tachypneic and saturating 80% on ambient air on their arrival. En route, he received nebulized albuterol, nitroglycerin and was started on non-invasive positive pressure ventilation (NI-PPV).

On arrival, he remains uncomfortable-appearing with a respiratory rate of 35 breaths/min and accessory muscle use. His heart rate is 136bpm, blood pressure is 118/85mmHg, and he is saturating 95% on an FiO2 of 100%. Attempts to obtain a history are limited due to difficulty comprehending his responses with the PPV mask on, and prompt desaturation with it off. Lung auscultation is similarly challenging due to ambient and transmitted sounds, although basilar crackles and diffuse expiratory wheezing are appreciated. Cardiovascular examination reveals a rapid and irregularly irregular rhythm. Assessment of jugular venous distension is limited due to the patient’s body habitus and the presence of mask straps around the patient’s neck. Lower extremities demonstrate 2+ pitting edema, symmetric bilaterally. Intravenous access is established and laboratory tests are sent. The ECG technician and portable chest x-ray are called.

The case presentation above demonstrates a common emergency department scenario: a critically-ill patient with undifferentiated dyspnea. Specifically, the scenario reveals a situation where the physical examination is either obfuscated by technical challenges or otherwise indeterminate. The patient is at risk for deterioration and targeted intervention is mandatory. If a COPD exacerbation is assumed, additional nebulized breathing treatments are indicated – a potentially costly jolt of beta agonists if the patient’s atrial fibrillation and rapid ventricular response are the consequence of decompensated systolic heart failure. Take the route of decompensated CHF and prompt afterload reduction with diuresis would be next – if incorrect, not only would the primary cause go untreated, but his tenuously-maintained blood pressure may suffer.

Algorithm for the Use of Ultrasound in the Evaluation of Dyspnea

Algorithm for the Use of Ultrasound in the Evaluation of Dyspnea

1. Lung Ultrasound

An approach incorporating point-of-care ultrasonography may be useful. First, a thoracic ultrasound is performed where certain causative etiologies might be identified immediately – for example absent lung sliding suggesting pneumothorax, or signs of generalized or subpleural consolidation.

The POCUS Atlas
The ultrasound images and videos used in this post come from The POCUS Atlas, a collaborative collection focusing on rare, exotic and perfectly captured ultrasound images.
The POCUS Atlas

Pneumothorax

Hepatization

Shred Sign

Pleural Effusion

2. Cardiac Ultrasound

Other findings on lung ultrasound may point to causes that are not primarily pulmonary. For example, if diffuse B-lines are encountered a focused cardiac ultrasound can be performed to grossly evaluate ejection fraction and estimate right atrial pressure.

B-Lines

Depressed EF

Dilated IVC

3. Venous Ultrasound

Finally, if the lung ultrasound is largely unremarkable (A-lines), a sequence of ultrasonographic findings including right ventricular dilation and the presence of a deep venous thrombosis would point to pulmonary embolism as the diagnosis.

DVT

RV Dilation

All illustrations are available for free, licensed (along with all content on this site) under Creative Commons Attribution-ShareAlike 4.0 International Public License.

Downloads Page License

References

  1. Lichtenstein DA, Mezière GA, Lagoueyte J-F, Biderman P, Goldstein I, Gepner A. A-lines and B-lines: lung ultrasound as a bedside tool for predicting pulmonary artery occlusion pressure in the critically ill. Chest. 2009;136(4):1014-1020. doi:10.1378/chest.09-0001.
  2. Copetti R, Soldati G, Copetti P. Chest sonography: a useful tool to differentiate acute cardiogenic pulmonary edema from acute respiratory distress syndrome. Cardiovasc Ultrasound. 2008;6(1):16. doi:10.1186/1476-7120-6-16.
  3. Gallard E, Redonnet J-P, Bourcier J-E, et al. Diagnostic performance of cardiopulmonary ultrasound performed by the emergency physician in the management of acute dyspnea. Am J Emerg Med. 2015;33(3):352-358. doi:10.1016/j.ajem.2014.12.003.
  4. Lichtenstein DA. Lung ultrasound in the critically ill. Ann Intensive Care. 2014;4(1):1. doi:10.1186/2110-5820-4-1.
  5. Zanobetti M, Scorpiniti M, Gigli C, et al. Point-of-Care Ultrasonography for Evaluation of Acute Dyspnea in the ED. Chest. 2017;151(6):1295-1301. doi:10.1016/j.chest.2017.02.003.
  6. Lichtenstein DA, Mezière GA. Relevance of lung ultrasound in the diagnosis of acute respiratory failure: the BLUE protocol. Chest. 2008;134(1):117-125. doi:10.1378/chest.07-2800.
  7. Images from The POCUS Atlas
  8. Special thanks to Dr. Timothy Jang, Director Emergency Ultrasound Program, Director Emergency Ultrasound Fellowship, Associate Professor of Clinical Emergency Medicine, Department of Emergency Medicine at Harbor-UCLA

Dyspnea

Causes of Dyspnea

Causes of Dyspnea

Findings in Selected Causes of Dyspnea

Condition History Symptoms Findings Evaluation
Anaphylaxis Exposure to allergen Abrupt onset, facial swelling Stridor, wheezing, hives  
PE Immobilization, malignancy, prior DVT/PE, surgery, OCP Abrupt onset, pleuritic chest pain Tachycardia, hypoxia ECG (RV strain)
CT PA, D-dimer
LE US (DVT)
Pneumonia Exposure, tobacco use Fever, productive cough Focal rales CXR
CBC
Blood/respiratory cultures
Pneumothorax Trauma, thin male Abrupt onset, chest pain Decreased BS, subQ emphysema, JVD and tracheal deviation if tension CXR
US
Fluid overload Dietary indiscretion, medication non-adherence Orthopnea, PND JVD, S3/S4, peripheral edema CXR
US
ECG
BNP
COPD/Asthma Tobacco use, personal/family history Progressive Retractions, accessory muscle use, wheezing CXR
US (distinguish from fluid overload)
Malignancy Tobacco use, weight loss Hemoptysis   CXR
CT Chest

References

  1. Braithwaite, S., & Perina, D. (2013). Dyspnea. In Rosen’s Emergency Medicine – Concepts and Clinical Practice (8th ed., Vol. 1, pp. 206-213). Elsevier Health Sciences.