Review Articles

Jan 062020
 
ICU Physiology in 1000 Words: Shorthand Equations for Respiratory System Power

Jon-Emile S. Kenny MD [@heart_lung] Background This synopsis will address the basic geometric calculation of respiratory system work for a single breath [in joules] and power [i.e. joules/seconds or watts] which is work multiplied by the respiratory rate.  This geometric approach will then be used to explain two shorthand equations – the second of which was [… read more]

Jan 052020
 
New Guideline for Treatment of Drug-Resistant Tuberculosis

New Guideline Emphasizes Treatment of Drug-Resistant Tuberculosis with All-Oral Regimens for MDR-TB Patients The American Thoracic Society, Centers for Disease Control and Prevention, European Respiratory Society and the Infectious Diseases Society of America have published an official clinical guideline on the treatment of drug-resistant tuberculosis (DR-TB) in the Nov. 15 American Journal of Respiratory and [… read more]

Dec 212019
 
ICU Physiology in 1000 Words: Asthmatic Mechanics

Jon-Emile S. Kenny MD [@heart_lung] Recently, Josh Farkas and Scott Weingart gave a series of engrossing posts and podcasts on asthma.  I especially liked their deliberations on mechanical ventilation which inspired me – no pun intended – to create a vodcast of my own and, like a novice troubleshooting a ventilator alarm, poke and prod at [… read more]

Dec 122019
 
Patients who say they're allergic to penicillin are usually wrong

More than 32 million people in the U.S. have reported penicillin allergies — about 10% of the population. But almost 95% of them are not penicillin-allergic, and are removing themselves from eligibility for ideal antibiotic treatments, according to a review in JAMA. “More than 1 in 10 people who seek medical care self-report a history [… read more]

Dec 062019
 
Navigational bronchoscopy real-world diagnostic yields reported

Electromagnetic navigation bronchoscopy (ENB) can allow biopsy of peripheral pulmonary nodules that are usually not accessible with conventional bronchoscopy. Navigational bronchoscopy requires specialized training and equipment costing hundreds of thousands of dollars, and is not widely available outside urban centers. Multiple studies have reported varying yields and complication rates with ENB, but most have been [… read more]

Nov 302019
 
ICU Physiology in 1000 Words: Pulmonary Embolism & Right Ventricular Ischemia

Jon-Emile S. Kenny MD [@heart_lung] Commonly, we are sold that acute pulmonary thromboembolism [PE] burns the right ventricular [RV] candle at both ends.  This is because perfusion of the right coronary artery [RCA] is mediated by both its upstream mean arterial pressure [MAP] and downstream right ventricular end-diastolic pressure [RVEDP].  Given that a PE may decrease [… read more]

Nov 242019
 
ICU Physiology in 1000 Words: Pulmonary Embolism & Pulmonary Vascular Resistance

Jon-Emile S. Kenny MD [@heart_lung] What if I told you that in acute pulmonary thromboembolism [PE] that the initiation of intravenous norepinephrine [NE] decreases the calculated pulmonary vascular resistance [cPVR]?  Would you believe me?  Certainly, you would trust that an infusion of a thrombolytic does so.  Of great interest, both NE and thrombolytics decrease the cPVR [… read more]

Nov 112019
 
ICU Physiology in 1000 Words: Pulmonary Embolism & Syncope

Jon-Emile S. Kenny MD [@heart_lung] The transient and reversible loss of consciousness that may accompany pulmonary embolism [PE] is well-documented [1-7].  This brief post will not address the controversy regarding the prevalence of PE in ‘unexplained’ syncope; rather, it will focus on pathomechanisms and serve as the foundation for a few forthcoming entries on pulmonary thromboembolism [… read more]

Nov 082019
 
New guidelines on obesity hypoventilation syndrome released

Tens of millions of adults in the U.S. have obstructive sleep apnea (OSA), but most are mild cases that pose low health risks. A greater danger is faced by the smaller number of people with sleep apnea that progresses to obesity hypoventilation syndrome (OHS), a life-threatening condition. Obesity hypoventilation syndrome — an impairment in resting [… read more]

Oct 302019
 
Vaping-Associated Lung Injury – Part 2

Jon-Emile S. Kenny MD [@heart_lung] “There are sadistic scientists who hurry to hunt down errors instead of establishing the truth.” -Marie Curie In part 1 of Vaping-Associated Lung Injury, the very basics of electronic nicotine delivery systems [ENDS] were covered as well as highlights on clinical presentation, radiology and pathology.  In this second part, flurries of [… read more]

Oct 292019
 
Vaping-Associated Lung Injury – Part 1

Jon-Emile S. Kenny MD [@heart_lung] with illustration by Carla M. Canepa MD [@_carlemd_] “Inside the word ‘emergency’ is ‘emerge’; from an emergency, new things come forth.” -Rebecca Solnit Case A 32-year-old man is admitted with three days of fevers, chills, malaise, dyspnea and productive cough.  He works in a stressful job in the heart of Manhattan [… read more]

Oct 212019
 
2019 IDSA Guidelines for Community Acquired Pneumonia in Adults: To HCAP, we just say fare thee well

Jon-Emile S. Kenny MD [@heart_lung] with illustrations by Carla M. Canepa MD [@_carlemd_] “Better never means better for everyone… It always means worse, for some.” -Margaret Atwood Case A 73-year-old woman with a history of severe chronic bronchitis, ESRD receiving thrice-weekly hemodialysis and heart failure with a preserved ejection fraction is admitted from home with fevers, [… read more]

Apr 162019
 
More than 90% of sepsis deaths are unpreventable, study concludes

“Nihilist” is one of the harshest insults that can be lobbed at a physician. Even while one knows intellectually that every patient can’t be saved, it’s considered odious to openly acknowledge that actuarial reality. Accepting the truth that some patients will inevitably die despite our best efforts is seen by some as the threshold of [… read more]

Mar 292019
 
ICU Physiology in 1000 Words: The Driving Power & Ventilator-Induced Lung Injury

Jon-Emile S. Kenny MD [@heart_lung] The mechanical power applied to the lung is a risk factor for ventilator or ventilation-induced lung injury [VILI] [1-4].  But can the work done to the lung over time be homogenized into a single value?  Could different components of the power equation carry different VILI risk beyond their mathematical inequalities [… read more]

Mar 262019
 
ICU Physiology in 1000 Words: The Mechanical Power & Ventilator-Induced Lung Injury

Jon-Emile S. Kenny MD [@heart_lung] A few years ago I was intrigued by a new concept in Ventilator-Induced Lung Injury [VILI] – the mechanical power.  I employed this paradigm, introduced by Gattinoni’s group, as an opening for the ‘ARDS Trilogy.’  Since then, I have also discussed this ‘ergotrauma’ in the context of helium-oxygen physiology and [… read more]

Feb 032019
 
ICU Physiology in 1000 Words: Blood Pressure

Jon-Emile S. Kenny MD [@heart_lung] Why is blood pressure measured by units of length [i.e. millimeters of mercury – mmHg]?  What decides systolic and diastolic pressure?  What are the determinants of tissue perfusion and what are the clinical implications of this physiology?  Can we deceive ourselves into thinking a particular mean arterial pressure [MAP] is [… read more]

Jan 162019
 
Atrial Fibrillation for the Intensivist – part 2

Jon-Emile S. Kenny MD [@heart_lung] “I’m burnin’ through the sky, yeah Two hundred degrees, That’s why they call me Mister Fahrenheit” -Freddie Mercury Part 1 gave a brief overview of the mechanisms of atrial fibrillation [AF] as well as pertinent features of rate controlling agents and anticoagulation.  In this brief second part, nuanced features of ventricular [… read more]

Jan 152019
 
Atrial Fibrillation for the Intensivist – part 1

Jon-Emile S. Kenny MD [@heart_lung] with illustrations by Carla M Canepa MD [@_carlemd_] “The habit of writing for my eye is good practice. It loosens the ligaments.” ― Virginia Woolf Case A 28 year old woman with known severe mitral stenosis from rheumatic heart disease presents with acute onset shortness of breath.  Her acute dyspnea began while [… read more]

Jan 132019
 
Vitamin D supplementation reduced COPD exacerbations in deficient patients: meta-analysis

by Salynn Boyles, Contributing Writer, MedPage Today Vitamin D supplements reduced moderate to severe COPD exacerbations in patients with low circulating levels of its 25-hydroxyvitamin D (25-OH-D) metabolite at baseline, a meta-analysis indicated. But no such effect was seen for patients with at least normal 25-OH-D levels (at least 25 nmol/L) prior to supplementation, according to Adrian [… read more]

Jan 012019
 
Best of 2018 on PulmCCM

Best of 2018:       Prone positioning for severe ARDS advised by major societies    2018 Update to Surviving Sepsis Guidelines: Cue Backlash   Management of Ground Glass and Subsolid Pulmonary Nodules: Review   Vasopressors and Inotropes for Shock Syndromes: Review     Prophylactic Precedex prevented delirium in ICU patients   Corticosteroids do help [… read more]