Critical Care

Jul 302020
 
ICU Physiology in 1000 Words: Patient Self-Inflicted Lung Injury – Part 2

Jon-Emile S. Kenny MD [@heart_lung] In part 1, evidence for and against spontaneous breathing effort in acute respiratory distress syndrome [ARDS] was briefly outlined.  The mechanisms of patient self-inflicted lung injury [P-SILI] are touched upon herein with reconciliation of the clinical and experimental data. Mechanisms: basics A handful great reviews on spontaneous breathing in ARDS and [… read more]

Jul 302020
 
ICU Physiology in 1000 Words: Patient Self-Inflicted Lung Injury – Part 1

Jon-Emile S. Kenny MD [@heart_lung] Background In an excellent review from early 2016, Gattinoni and Quintel note that ventilator induced lung injury [VILI] is better considered ventilation induced lung injury because VILI can develop during spontaneous breathing [1].  To support this claim, they reference a classic experimental study from the late 1980s by Mascheroni and colleagues [… read more]

Jun 302020
 
A Brief Overview of Corticosteroids in COVID-19

Jon-Emile S. Kenny MD [@heart_lung] “ This is the way the world ends Not with a bang but with a whimper.” -T.S. Eliot As lightly discussed a few months ago, deploying corticosteroids in COVID-19 began, expectedly, with controversy.  Russell and colleagues submitted a letter arguing against wholesale administration of corticosteroids in patients infected with SARS-CoV-2.  They [… read more]

Jun 282020
 
A Brief Update on Angiotensin & Aldosterone Inhibition in COVID-19

Jon-Emile S. Kenny MD [@heart_lung] “We’re on a road to nowhere …” -David Byrne Background In early March of this year, Fang and colleagues published a letter noting that patients with diabetes and/or hypertension treated with ACE inhibitors or angiotensin II type-1 receptor blockers [i.e. ARBs] increase their expression of the ACE2 enzyme.  Parenthetically, they also stated [… read more]

May 302020
 
COVID-19 Associated Coagulopathy: a contentious conundrum

Jon-Emile S. Kenny MD [@heart_lung] “Knavery and flattery are blood relations.” -Abraham Lincoln Background SARS-CoV-2 is a positive-sense, single-stranded RNA virus with spiked surface glycoproteins  emanating from its viral envelope.  It is a member of the Coronaviridae family, similar to the first SARS [SARS-CoV] and the Middle East Respiratory Syndrome [MERS].  SARS-CoV-2 preferentially targets respiratory epithelium, [… read more]

Mar 252020
 
An Illustrated Primer on COVID-19 Therapy: part 2

Jon-Emile S. Kenny MD [@heart_lung] with illustrations by Carla M. Canepa MD [@_carlemd_] “…fires had been put out by volunteers using brickmason’s ladders and buckets of water carried in from wherever it could be found, and methods so disorderly that they sometimes caused more damage than the fires.” – Gabriel García Márquez In this second primer [… read more]

Mar 162020
 
An Illustrated Guide to the Chest CT in COVID-19

Jon-Emile S. Kenny MD [@heart_lung] with illustrations by Carla M. Canepa MD [@_carlemd_] “He found a glimmer of hope in the ruins of disaster …” – Gabriel García Márquez Background  The coronavirus moniker originates from the appearance of the virus under the electron microscope – protein peplomers radiating from the viral envelope like a crown.  Prior [… read more]

Mar 092020
 
ICU Physiology in 1000 Words: All Perfusion Is Local

Jon-Emile S. Kenny MD [@heart_lung] About a year ago, I explored blood pressure – underscoring mean arterial pressure [MAP] as a determinant, but not necessarily an indicator, of perfusion.  The inspiration for that post were these excellent reviews [1, 2] by the legendary Dr. Magder. With the recent 65 Trial [3], a deeper exploration of tissue [… read more]

Feb 092020
 
Vitamin C didn't improve septic shock in VITAMINS trial

A new randomized trial showed no benefit from intravenous vitamin C in patients with sepsis, but delays in treatment baked into the trial design will keep hope alive for true believers in the novel therapy. Vitamin C, hydrocortisone, and thiamine have been promoted as a lifesaving adjunctive therapy for septic shock, based on anecdotal data [… read more]

Feb 092020
 
The ‘Lacto-Bolo Reflex’

Jon-Emile S. Kenny MD [@heart_lung] “Sich regen bringt Segen” -German proverb Background It is an overcast day in Bern, Switzerland.  I have recently left Zermatt, having had the honour and pleasure of speaking at ‘The Big Sick’ conference.  I spent the day roaming the narrowed passages of this old, beautiful city.  In the midst of my [… read more]

Jan 202020
 
Adding Vitamin D no help in critical illness, even in deficient patients

Vitamin D supplementation brought no measurable benefits to vitamin D-deficient critically ill patients, in a large randomized trial published in the New England Journal of Medicine. Vitamin D supplementation has long been hoped for as a potential lifesaving therapy in critical illness. Many critically ill patients are vitamin D deficient, and deficiency increases the risk [… read more]

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]

Dec 272019
 
The PHARLAP Trial: Recruitment Maneuvers Buy Stairway to Heaven?

Jon-Emile S. Kenny MD [@heart_lung] “Dying is a wild night and a new road.” -Emily Dickinson Background In 2006, a recruitment maneuver to achieve an ‘open lung’ was circulated; it has since been dubbed ‘stairway recruitment’ given its stepwise upthrusts in airway pressure [see figure 1]: Plodding up this ladder of airway pressure was meant to [… 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 052019
 
Intubating robots are coming for your job (someday)

Undergraduate biomedical engineering students have developed the first prototype of a laryngoscope blade whose future iterations could allow novices or robots to intubate patients as well as expert humans. The new laryngoscope blade has embedded force sensors that calculate its location in the airway. The sensors were trained using machine learning, with tactile patterns generated [… 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]