18. A Case of Severe Weakness in the ICU

We are thrilled here @PulmPEEPS to have our first episode with one of our new Associate Editors Luke Hedrick, and our first nephrology consultant Jeff William. Luke will walk us through an interesting case presentation, and we will discuss an approach to severe weakness in our patient in the ICU.

Meet Our Guests

Jeff William is an Assistant Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, where he is also the Associate Director of the Nephrology Fellowship Program. He completed a Medical Education Research Fellowship at Harvard Medical School, and is very involved in residency, fellowship and medical student education.

Patient Presentation

We have a man in his 40s with a past medical history of asthma, hypertension, and acid reflux who was brought in by EMS with back pain and profound proximal lower extremity weakness. He reports mild weakness in his legs which started 2 days ago, but this morning his weakness acutely worsened to the point that he can’t lift his legs out of the bed. He also has some cramping pain in his thighs. He additionally has had mild shortness of breath and yesterday went to an urgent care where he was given steroids and swabbed for COVID (which was negative).

Key Learning Points

**Spoilers Ahead** If you want to think through the case on your own we advise listening to the episode first before looking at the infographics below

Although our patient’s etiology of severe hypokalemia was thought to be secondary to thiazide diuretic use, it is important to be familiar with hypokalemic periodic paralysis.

References

  1. Knochel JP, Schlein EM. On the mechanism of rhabdomyolysis in potassium depletion. J Clin Invest. 1972 Jul;51(7):1750-8. doi: 10.1172/JCI106976.
  2. Wang X, Han D, Li G. Electrocardiographic manifestations in severe hypokalemia. J Int Med Res. 2020 Jan;48(1):300060518811058. doi: 10.1177/0300060518811058.
  3. Venance SL, Cannon SC, Fialho D, Fontaine B, Hanna MG, Ptacek LJ, Tristani-Firouzi M, Tawil R, Griggs RC; CINCH investigators. The primary periodic paralyses: diagnosis, pathogenesis and treatment. Brain. 2006 Jan;129(Pt 1):8-17. doi: 10.1093/brain/awh639.
  4. Lin SH, Lin YF, Halperin ML. Hypokalaemia and paralysis. QJM. 2001 Mar;94(3):133-9. doi: 10.1093/qjmed/94.3.133. 
  5. Lin SH, Lin YF, Chen DT, Chu P, Hsu CW, Halperin ML. Laboratory tests to determine the cause of hypokalemia and paralysis. Arch Intern Med. 2004 Jul 26;164(14):1561-6. doi: 10.1001/archinte.164.14.1561.

12. Undifferentiated Shock Roundtable

This week the Pulm PEEPs, David Furfaro and Kristina Montemayor, are joined by three outstanding critical care doctors and medical educators to discuss the evaluation of patients with undifferentiated shock. We cover everything from the basics about defining shock, to advanced POCUS techniques to clarify the etiology of shock. Listen today and let us know your favorite technique for evaluating shock in the ICU.

Meet Our Guests

Molly Hayes is an Assistant Professor of Medicine at Beth Israel Deaconess Medical Center and Harvard Medical School, the Director of the MICU at BIDMC, and the Director of External Education at the Carl J Shapiro Institute for Education and Research. She is also a course director for a yearly CME course on principles of critical care medicine run by BIDMC and HMS.

Nick Mark is a Pulmonologist and Intensivist at Swedish Medical Center in Seattle, Washington. He is also the founder of ICU One Pager, which produces high yield critical care education one-page guides that have been downloaded by thousands of learners.

Matt Siuba is an Assistant Professor of Medicine and intensivist at the Cleveland Clinic, where he is the associate program director for the Critical Care Medicine fellowship. He founded and runs the website Zentensivist.com, has his own associated podcast, and is a senior editor at CriticalCareNow.com.

Key Learning Points

Key graphics

Courtesy of Nick Mark and ICU One Pager
Courtesy of Matt Siuba
Courtesy of Nick Mark and ICU One Pager

Definition of shock

– Shock is defined as inadequate oxygen delivery to meet the body’s needs. Decreased perfusion and oxygen delivery leads to cell injury and death

– If you define just as hypotension, you will miss people who have cryptic shock, and categorize some people with shock who don’t have it

– Cryptic shock = a patient with normal blood pressure (MAP > 65), but who still has shock based on inadequate O2 delivery

– O2 delivery is broken down in to cardiac output and arterial oxygen content

Causes of shock

Shock can be divided into three large categories:

1) A pump problem – low cardiac output. This includes cardiogenic and obstructive shock. Make sure to remember to look for tamponade and valvulopathies.

2) A pipe problem – low systemic vascular resistance. This includes distributive shock. Distributive shock is most often due to sepsis but can be due to anaphylaxis, endocrinopathies, cirrhosis, or spinal shock.

3) A tank problem – low preload. This includes hypovolemic and hemorrhagic shock. Make sure to remember about high intrathoracic pressure, which can decrease effective preload.

Examining a patient with undifferentiated shock

– See if the patient is on the “Shock BUS” by examining their brain (mental status), urine output, and skin

– Feel if their skin is warm vs cold and if it is mottled

– Feel the patient’s pulses to see if they are bounding, normal, or thready

Point of Care Ultrasound

– “Ultrasound is the new stethoscope”

– The first step is to always look at the heart and look for chamber size and function. You can then look for pericardial effusion

– Point of care ultrasound then includes looking at the lungs for signs of fluid overload, consolidation, or pneumothorax

– A complete ultrasound also involves looking at the abdomen and at the extremities for DVT

– More specific ultrasound techniques include looking at:

1) IVC exam to estimate right atrial pressure. This test is often misused. It is most helpful in states when the patient has low stroke volume and trying to figure out if they have cardiac limitation to stroke volume vs if they are hypovolemic.

2) Velocity time index as a measure of cardiac output to trend with interventions

References and links for further reading

  1. Vincent JL, De Backer D. Circulatory shock. N Engl J Med. 2013;369(18):1726-1734. doi:10.1056/NEJMra1208943
  2. Seymour CW, Liu VX, Iwashyna TJ, et al. Assessment of Clinical Criteria for Sepsis: For the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016;315(8):762-774. doi:10.1001/jama.2016.0288
  3. Chukwulebe SB, Gaieski DF, Bhardwaj A, Mulugeta-Gordon L, Shofer FS, Dean AJ. Early hemodynamic assessment using NICOM in patients at risk of developing Sepsis immediately after emergency department triage. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. 2021;29(1):23. doi:10.1186/s13049-021-00833-1
  4. Hernández G, Ospina-Tascón GA, Damiani LP, et al. Effect of a Resuscitation Strategy Targeting Peripheral Perfusion Status vs Serum Lactate Levels on 28-Day Mortality Among Patients With Septic Shock: The ANDROMEDA-SHOCK Randomized Clinical Trial. JAMA. 2019;321(7):654-664. doi:10.1001/jama.2019.0071
  5. Wang J, Zhou D, Gao Y, Wu Z, Wang X, Lv C. Effect of VTILVOT variation rate on the assessment of fluid responsiveness in septic shock patients. Medicine (Baltimore). 2020;99(47):e22702. doi:10.1097/MD.0000000000022702
  6. Sweeney DA, Wiley BM. Integrated Multiorgan Bedside Ultrasound for the Diagnosis and Management of Sepsis and Septic Shock. Semin Respir Crit Care Med. 2021;42(5):641-649. doi:10.1055/s-0041-1733896
  7. Yuan S, He H, Long Y. Interpretation of venous-to-arterial carbon dioxide difference in the resuscitation of septic shock patients. J Thorac Dis. 2019;11(Suppl 11):S1538-S1543. doi:10.21037/jtd.2019.02.79
  8. Volpicelli G, Lamorte A, Tullio M, et al. Point-of-care multiorgan ultrasonography for the evaluation of undifferentiated hypotension in the emergency department. Intensive Care Med. 2013;39(7):1290-1298. doi:10.1007/s00134-013-2919-7
  9. Perera P, Mailhot T, Riley D, Mandavia D. The RUSH exam: Rapid Ultrasound in SHock in the evaluation of the critically lll. Emerg Med Clin North Am. 2010;28(1):29-56, vii. doi:10.1016/j.emc.2009.09.010

Radiology Rounds – 3/8/22

We’re excited to bring you another Radiology Rounds today that combines pulmonary and critical care.

The patient is diagnosed with small cell lung cancer and requires a left bronchial stent. She develops acute hypoxemic and hypercapnic respiratory failure requiring intubation.

You are concerned that she has increased airway resistance as a result of stent migration. What would you expect to see on the ventilator if this is the case?

Here are some tips from ICU OnePager on interpreting high peak pressures on the ventilator

6. PEEP in ARDS Roundtable

This week on Pulm PEEPs, Dave Furfaro and Kristina Montemayor are joined by experts in the field of critical care medicine and ARDS to discuss all things PEEP! Drs. Roy Brower, Sarina Sahetya, Todd Rice, and Elias Baedorf-Kassis discuss everything ranging from PEEP basics to their approach to optimizing PEEP in patients with ARDS.

Meet Our Guests

Roy Brower is a Professor of Medicine at Johns Hopkins where he served as the MICU director for over 33 years, and he has been one of the pioneers for lung-protective ventilation for patients with ARDS.

Elias Baedorf-Kassis is an Assistant Professor of Medicine at Beth Israel Deaconess Medical Center and Harvard Medical School. He is the Medical Director of Respiratory Care at BIDMC, and helps lead the VV-ECMO program.

Todd Rice is an Associate Profess of Medicine in the Division of Allergy, Pulmonary, and Critical Care Medicine at Vanderbilt University and Vice President for Clinical Trial Innovation and Operations in the Vanderbilt Institute for Clinical and Translational Research.

Sarina Sahetya is an Assistant Professor of Medicine at Johns Hopkins Hospital and does research in the diagnosis and treatment of ARDS.


Key Learning Points

Driving Pressure figure from Amato et al. 2015. Stress index figure from Hess 2014.
  • The plateau pressure can be measured on the ventilator with an inspiratory hold maneuver
  • Extrinsic PEEP is applied by the ventiilator, while intrinsic PEEP, or auto-PEEP, occurs when there is incomplete emptying of the lungs due to inadequate time for exhalation. This often happens with obstructive lung disease. Intrinsic PEEP can be measured on the ventilator with an end-expiratory hold maneuver
  • We utilize PEEP in all intubated patients to minimize atelectasis. When patients are supine, the heart moves back 2 cm and the diaphragm raises by 2 cm, so often the left lower lobe of the lung is compressed and there is atelectasis there. This is often seen on CXR:

References, Image Sources, and Further Reading

  1. Higher versus Lower Positive End-Expiratory Pressures in Patients with the Acute Respiratory Distress Syndrome. New England Journal of Medicine. 2004;351(4):327-336. doi:10.1056/NEJMoa032193
  2. Amato MBP, Meade MO, Slutsky AS, et al. Driving Pressure and Survival in the Acute Respiratory Distress Syndrome. New England Journal of Medicine. 2015;372(8):747-755. doi:10.1056/NEJMsa1410639
  3. Writing Group for the Alveolar Recruitment for Acute Respiratory Distress Syndrome Trial (ART) Investigators. Effect of Lung Recruitment and Titrated Positive End-Expiratory Pressure (PEEP) vs Low PEEP on Mortality in Patients With Acute Respiratory Distress Syndrome: A Randomized Clinical Trial. JAMA. 2017;318(14):1335-1345. doi:10.1001/jama.2017.14171
  4. Beitler JR, Sarge T, Banner-Goodspeed VM, et al. Effect of Titrating Positive End-Expiratory Pressure (PEEP) With an Esophageal Pressure-Guided Strategy vs an Empirical High PEEP-Fio2 Strategy on Death and Days Free From Mechanical Ventilation Among Patients With Acute Respiratory Distress Syndrome: A Randomized Clinical Trial. JAMA. 2019;321(9):846-857. doi:10.1001/jama.2019.0555
  5. LaFollette R, Hojnowski K, Norton J, DiRocco J, Carney D, Nieman G. Using pressure–volume curves to set proper PEEP in acute lung injury. Nursing in Critical Care. 2007;12(5):231-241. doi:10.1111/j.1478-5153.2007.00224.x
  6. Hess DR. Respiratory mechanics in mechanically ventilated patients. Respir Care. 2014;59(11):1773-1794. doi:10.4187/respcare.03410
  7. Sahetya SK, Hager DN, Stephens RS, Needham DM, Brower RG. PEEP Titration to Minimize Driving Pressure in Subjects With ARDS: A Prospective Physiological Study. Respir Care. 2020;65(5):583-589. doi:10.4187/respcare.07102
  8. Umbrello M, Chiumello D. Interpretation of the transpulmonary pressure in the critically ill patient. Ann Transl Med. 2018;6(19):383. doi:10.21037/atm.2018.05.31
  9. Kenny JES. ICU Physiology in 1000 Words: Driving Pressure & Stress Index. PulmCCM. Published February 13, 2016. Accessed January 1, 2022. https://pulmccm.org/review-articles/icu-physiology-in-1000-words-driving-pressure-stress-index/

Radiology Rounds – 12/28/21

Today we’re bringing you a special edition of Radiology Rounds complete with classic imaging, and some key critical care and ventilator physiology. This case is a perfect lead-in for next week’s Pulm PEEPs Roundtable on PEEP titration, so make sure to tune in!

How would you best describe the imaging findings?


There are bilateral, diffuse alveolar infiltrates noted on imaging with evidence of an air bronchogram on the CT image.

The patient develops worsening hypoxemia requiring mechanical intubation. The patient has multifocal pneumonia and requires intubation. ABG is performed and the calculated PaO2:FIO2 ratio is 150. How would you describe the severity of ARDS?


This patient has moderate ARDS based on a PaO2:FIO2 ratio that is between 100 and 200. The patient’s initial ventilator settings on volume control are:

Based on these parameters, we can also calculate the driving pressure. Driving pressure is calculated by using Pplat-PEEP. In this case, Pplat (30)-PEEP (10), would give a driving pressure of 20.

4. Top Consults: Hemoptysis

Pulm PEEPs hosts, Kristina Montemayor and David Furfaro, bring our first episode in our Top Consults series. In this series, we will bring in experts to work through the most common pulmonary and critical care consults. Whether you are the consulting physician, or a pulmonologist responding to the page, these episodes are geared to give you all the information you need to care for your patients!

Today, we are joined by Chris Kapp and Matthew Schimmel, two interventional pulmonologists, to discuss hemoptysis. Chris and Matt will help us work through two hemoptysis consults, and together we’ll provide a framework for thinking about hemoptysis, outline some key components of the evaluation, and delve into treatment options.

Key Learning Points

Hemoptysis Evaluation

Hemoptysis Management

Life-Threatening or Large Volume Hemoptysis

  1. Stabilize the patient! Make sure the airway is protected either by the patient coughing themselves, or intubation if needed. Provide hemodynamic support with IVF, blood products, and pressors if needed. If it is known which lung has the bleeding the patient can be positioned so the lung with the bleeding is down. This protects the non-bleeding lung.
  2. Correct any bleeding diathesis If the patient is on anti-coagulation, or has any reversible bleeding diathesis, these should be corrected immediately to reduce further bleeding.
  3. Localize the bleed If the patient is stable, they should undergo a CTA to localize the bleeding. If they are not stable to make it to a CT scan, a bronchoscopy should be performed.
  4. Bronchoscopic treatment In addition to clearing blood from the airway, bronchoscopy can localize the bleeding. With available expertise, bronchoscopic treatments can be performed such as ice saline, topical epinephrine, or balloon tamponade to isolate the bleed.
  5. Definitive therapy with arteriography and embolization Patients with life-threatening hemoptysis should ultimately undergo arteriography and embolization of any bleeding vessel. If this is not possible, then surgery can be needed in some cases.
  6. A note on diffuse hemoptysis If there is not one distinct bleeding lesion, then localizing and treating the bleed becomes more difficult. For diffuse alveolar hemorrhage, evaluation should be performed for if it is primary, and due to an immunologic cause and capillaritis, or secondary to a systemic disease and / or bleeding diathesis. These investigations will guide available treatment options. Capillaritis from an immunologic cause, such as lupus or vasculitis, can be treated with systemic glucocorticoids and an additional immunosuppressive agent such as cyclophosphamide or rituximab.

Non-life-threatening or Small Volume Hemoptysis

  1. Monitor for clinical worsening Patient’s should be monitored, either in the in-patient or out-patient setting, for increased volume or frequency of hemoptysis and for any clinical worsening, such as desaturations or decreased ability to clear the airway.
  2. Correct any bleeding diathesis If the patient is on anti-coagulation, or has any reversible bleeding diathesis, these should be corrected immediately to reduce further bleeding. In pattients with non-life-threateneing hemoptysis this requires careful consideration of balancing the risk of bleeding vs the benefits for continuing anti-coagulation.
  3. Evaluate for underlying cause Patient’s should undergo imaging and evaluation for the underlying cause of the hemoptysis. This may be evidence of an underlying infection, a pulmonary embolism, or new lung lesions making the patient at risk. If the source can’t be found on non-invasive imaging, and there is no clear systemic source such as an infection, a bronchoscopy is warranted. Any underlying cause should be treated and investigated further.
  4. Inhaled Tranexamic Acid Nebulized tranexamic acid is well tolerated and can help resolve hemopytysis without invasive procedures.

References and links for further reading

  1. Gagnon S, Quigley N, Dutau H, Delage A, Fortin M. Approach to Hemoptysis in the Modern Era. Can Respir J. 2017;2017:1565030. doi:10.1155/2017/1565030
  2. Radchenko C, Alraiyes AH, Shojaee S. A systematic approach to the management of massive hemoptysis. J Thorac Dis. 2017;9(Suppl 10):S1069-S1086. doi:10.21037/jtd.2017.06.41
  3. Davidson K, Shojaee S. Managing Massive Hemoptysis. Chest. 2020;157(1):77-88. doi:10.1016/j.chest.2019.07.012
  4. Lara AR, Schwarz MI. Diffuse Alveolar Hemorrhage. CHEST. 2010;137(5):1164-1171. doi:10.1378/chest.08-2084
  5. Wand O, Guber E, Guber A, Epstein Shochet G, Israeli-Shani L, Shitrit D. Inhaled Tranexamic Acid for Hemoptysis Treatment: A Randomized Controlled Trial. Chest. 2018;154(6):1379-1384. doi:10.1016/j.chest.2018.09.026