Mechanical Ventilation

Sep 122020
 
More on Corticosteroids in COVID-19 – Part 2: REACT meta-analysis

Jon-Emile S. Kenny MD [@heart_lung] “As human beings, don’t we need questions without answers as well as questions with answers?” -Alan Lightman With the publication of REMAP-CAP, CAPE-COVID and CoDEX, the World Health Organization [WHO] Rapid Evidence Appraisal for COVID-19 Therapies [REACT] Working Group combined these results with 4 other randomized trials of corticosteroids in COVID-19.  [… read more]

Sep 102020
 
More on Corticosteroids in COVID-19 – Part 1: REMAP-CAP, CAPE-COVID & CoDEX trials

Jon-Emile S. Kenny MD [@heart_lung] “Let us try to assume our fundamental ambiguity.” -Simone de Beauvoir When the pre-peer review RECOVERY trial was released in mid-June of this year, clinicians lost equipoise to enroll hospitalized patients receiving at least oxygen for COVID-19 into trials including a treatment arm without corticosteroids.  This brought to an early-halt three [… 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]

Apr 302020
 
COVID-19 Associated ARDS: ‘CARDS’ & the L-Phenotype

Jon-Emile S. Kenny MD [@heart_lung] “No facts are to me sacred; none are profane; I simply experiment, an endless seeker with no Past at my back.” -Ralph Waldo Emerson Background  When Drs. Marini and Gattinoni author a letter describing a new phenotype of the acute respiratory distress syndrome [ARDS] encountered in patients infected with SARS-CoV-2, we [… 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]

Aug 232019
 
APRV and Esophageal Manometry: a new way to titrate T-Low?

Jon-Emile S. Kenny MD [@heart_lung] “I had some dreams, they were clouds in my coffee, clouds in my coffee …” -Carly Simon Background  A recent letter to the editor in Critical Care posed a rather provocative question – ‘Are we really preventing lung collapse with APRV?’  The authors cited a case report of esophageal manometry used in [… read more]

Jun 092019
 
Dexmedetomidine helpful but inadequate alone for sedation (SPICE III)

In a new randomized trial, use of dexmedetomidine (Precedex) as the primary sedative in mechanically ventilated patients in the ICU resulted in no reduction in 90 day mortality. Dexmedetomidine resulted in a small improvement in delirium and ventilator days, but was almost never adequate to sedate patients on its own, and brought a small increase [… read more]

May 302019
 
Neuromuscular blockade for ARDS was no help, in supine patients

Continuous neuromuscular blockade for severe ARDS became common practice after the ACURASYS trial (2010) showed it reduced mortality by an absolute 9%. A larger trial, ROSE, now finds no benefit of the therapy over usual care — but leaves lingering questions due to major design differences. The ROSE trial was a multicenter randomized trial in [… read more]

Apr 292019
 
ICU Physiology in 1000 Words: The Respiratory System Pressure-Volume Curve

Jon-Emile S. Kenny MD [@heart_lung] More than 20 years ago Amato and colleagues reported a significant mortality reduction in ARDS patients who had their ventilator settings guided by the pressure-volume [PV] curve [1].  The 28-day mortality reduction was profound – 71% versus 38% – in favour of the patients who had their positive end-expiratory pressure [… read more]

Apr 282019
 
Open the Lung with Esophageal Manometry to Avoid VV-ECMO?

Jon-Emile S. Kenny MD [@heart_lung] “I am suffocated and lost when I have not the bright feeling of progression” -Margaret Fuller A recent letter and review in Critical Care have called for adoption of the ‘Open Lung Approach’ to patients with severe ARDS.  More specifically, in refractory ARDS whilst prone, it is argued that esophageal [… read more]

Apr 142019
 
Titrating PEEP using esophageal pressures did not improve ARDS outcomes (EPVent-2)

In acute respiratory distress syndrome (ARDS), using pleural pressure to adjust positive end-expiratory pressure (PEEP) has long been considered a cumbersome but theoretically ideal technique to optimize ventilator management. Using esophageal pressure as a surrogate for pleural pressure can allow one to calculate and minimize the transpulmonary pressure gradient, elevations in which are the putative [… read more]

Apr 072019
 
Bag-mask ventilation during intubation in ICU prevents severe hypoxemia

A randomized trial confirmed what most intensivists have long believed and practiced: in the moments before endotracheal intubation, we should help patients achieve the highest arterial oxygen saturation possible, using bag-mask ventilation (BMV). This seems self evident — why wouldn’t we? Bag-mask ventilation can distend the stomach with air, potentially increasing the risk for vomiting [… read more]

Mar 172019
 
Proton pump inhibitors did not improve outcomes in ICUs (SUP-ICU trial)

Proton pump inhibitors (PPIs) are widely prescribed to mechanically ventilated patients to prevent gastrointestinal (GI) bleeding. The evidence for their use is not strong; individual randomized trials have not shown a clear benefit over histamine blockers, but when many trials were pooled into meta-analyses, PPIs do appear to be superior. The Surviving Sepsis Guidelines have [… read more]

Mar 082019
 
How should we relate to "unreasonable" families in the ICU?

Most families have never suffered through a loved one experiencing prolonged critical illness and respiratory failure (defined as ventilator dependence for weeks, usually with a tracheostomy). But each year, more do. An estimated 400,000 people currently live with chronic critical illness in long-term acute care hospitals (LTACHs) and other facilities — a population that has [… read more]

Dec 162018
 
Daily chest X-rays the norm in ventilated patients, despite guidelines

More than 60% of patients receiving mechanical ventilation have continued to receive daily chest x-rays since the publication of guidelines recommending against the practice. The findings came from a database review of hundreds of thousands of patients and were published in JAMA Network Open. The American College of Radiology once recommended daily chest films in [… read more]

Nov 112018
 
ICU Physiology in 1000 Words: Volutrauma or Barotrauma?

Jon-Emile S. Kenny MD [@heart_lung] In a recent and excellent open-access review, Gattinoni, Quintel and Marini ask which is worse, volutrauma or atelectrauma [1]?  This concise review is an absolute must-read and forms the fabric from which this short article assembles.  Last spring – in Montreal – I was asked a few questions about volutrauma [… read more]

Oct 162018
 
Near Apneic Ventilation & Extracorporeal Membrane Oxygenation: close the lungs & keep them closed?

Jon-Emile S. Kenny MD [@heart_lung] “Once had a love and it was a gas …” -Blondie Case A 56 year old professor returns from a hiking trip in the ‘Four Corners’ area of New Mexico.  She was previously well and decided to rent a secluded desert cabin whilst writing a novel on the ethical obligations [… read more]

Oct 042018
 
Targeting normal oxygen saturation associated with death: meta-analysis

A new meta-analysis adds to the evidence that liberal use of supplemental oxygen may be harmful in acutely ill, hospitalized patients. Authors performed a meta-analysis of 25 randomized trials of acutely ill patients (total n ~ 16,000) treated with strategies of either “low” or “high” supplemental oxygenation. Although the cutoffs varied between studies, patients receiving [… read more]