Respiratory Failure & Mechanical Ventilation

I completed Quiz: 2️⃣ Control Variables!

I completed 2️⃣ Control Variables!

I completed 1️⃣ Breath Phases!

Notice that what it seems to be a right pneumothorax is actually bullae on the CT scan. Let pneumothorax is under pressure and chest tube was inserted!

However, on the CT scan taken post chest tube insertion, it seems that the tube is introduced into the lung!

Bilateral pulmonary masses, biopsy positive for adenocarcinoma.

Swelling in both hands and face associated with shortness of breath.

Chest tube drained around 1600 mL of yellowish clear fluid.

Bronchoscopy shows severe narrowing in the righ main bronchus, unable to pass the scope.

CXR 5 days ago:

CXR today

CT scan after intubation:

Loculated pneumothorax!

Bilateral apical pneumothoraces, approximately 10% in size on the right and 20-30% on the left without mediastinal shift with diffuse alveolar infiltrates and air bronchograms.

HOT COVID Trial

Lower vs Higher Oxygenation Target and Days Alive Without Life Support in COVID-19: The HOT-COVID Randomized Clinical Trial | Coronavirus (COVID-19) | JAMA | JAMA Network

In a multicenter trial involving 726 adults with COVID-19 and severe hypoxemia in European ICUs, targeting a partial pressure of oxygen (Pao2) of 60 mm Hg led to a median of 80 days alive without life support at 90 days, compared to 72 days for a Pao2 of 90 mm Hg (P=.009). No significant difference in mortality or serious adverse events was observed between the groups. This suggests that in severe COVID-19, a lower oxygenation target may improve outcomes without increasing risk.

HOT COVID Trial

Lower vs Higher Oxygenation Target and Days Alive Without Life Support in COVID-19: The HOT-COVID Randomized Clinical Trial | Coronavirus (COVID-19) | JAMA | JAMA Network

In a multicenter trial involving 726 adults with COVID-19 and severe hypoxemia in European ICUs, targeting a partial pressure of oxygen (Pao2) of 60 mm Hg led to a median of 80 days alive without life support at 90 days, compared to 72 days for a Pao2 of 90 mm Hg (P=.009). No significant difference in mortality or serious adverse events was observed between the groups. This suggests that in severe COVID-19, a lower oxygenation target may improve outcomes without increasing risk.

Extracorporeal Carbon Dioxide Removal to Avoid Invasive Ventilation During Exacerbations of Chronic Obstructive Pulmonary Disease: VENT-AVOID Trial – A Randomized Clinical Trial | American Journal of Respiratory and Critical Care Medicine (atsjournals.org)

In a U.S. trial involving 41 institutions and 113 patients with exacerbations of chronic obstructive pulmonary disease (COPD), the impact of extracorporeal CO2 removal (ECCO2R) on reducing ventilation time was assessed. The study, aiming for a sample size of 180, was prematurely halted due to slow enrollment. It explored whether ECCO2R could increase ventilator-free days within the first 5 days post-randomization. Participants were divided into those failing noninvasive ventilation (NIV, n=48) and those difficult to wean from invasive mechanical ventilation (IMV, n=65), receiving either standard care with ECCO2R or standard care alone.

Results revealed no statistically significant difference in median ventilator-free days at 5 days post-randomization between treatment arms across both strata (P=0.36). Specifically, in the NIV group,…

Videolaryngoscope versus Conventional Technique for Insertion of a Transesophageal Echocardiography Probe in Intubated ICU Patients (VIDLARECO trial). A Randomized Clinical trial - ScienceDirect

In a trial with 100 intubated critically ill patients, the use of a videolaryngoscope for transesophageal echocardiogram probe insertion significantly increased first-attempt success rates (90% vs. 58%, p < 0.001) and overall success (100% vs. 72%, p < 0.001), compared to the conventional method. Additionally, the videolaryngoscope group experienced notably fewer pharyngeal complications (14% vs. 52%, p < 0.001), demonstrating its efficacy and safety over traditional techniques in this patient population.

Extracorporeal Carbon Dioxide Removal to Avoid Invasive Ventilation During Exacerbations of Chronic Obstructive Pulmonary Disease: VENT-AVOID Trial | American Journal of Respiratory and Critical Care Medicine | Articles in Press (atsjournals.org)

This US trial, involving 113 COPD exacerbation patients, aimed to evaluate ECCO2R's effectiveness against standard care. The study, intended for 180 patients, was prematurely stopped due to slow enrollment. Results showed no significant improvement in ventilator-free days at Day 5 with ECCO2R. Specifically, in the non-invasive ventilation stratum, ECCO2R and standard care both recorded a median of 5 ventilator-free days, while in the invasive ventilation stratum, ECCO2R resulted in slightly more ventilator-free days (2 days vs 0.25 days), but without statistical significance. Notably, ECCO2R was associated with a higher in-hospital mortality rate in the non-invasive group (22% vs 0%).

64 years old male who is a heavy smoker with COPD and laryngeal carcinoma, s/p tracheostomy. He is addmitted now to the ICU complaining of air hunger. When connected to the ventilator; it showed the waves you see and the patient felt suffocation. Unfortunately, this is the only screenshot that was provided by Dr. Abdulhaseeb Tarabulsi.

Knowing that this is not a ventilator malfunction or circuit disconnection, what do you thing is happening?

Ventilator graphic of an intubated asthmatic patient on mechanical ventilation showing mild persistent flow at end of expiration indicating auto-PEEP:

The ventilator settings were changed as the following:

VT decreased from 470 to 420 mL.

Rate decreased from 20 to 16 breaths per minute but the patient is still breathing over.

The inspiratory time was decreased from 0.9 second to 0.6 second.

PRVC mode of ventilation with a targeted VT of 400, RR 26 and I:E ratio of 1:1.5. Notice the dynamic hyperinflation (autoPEEP) with persistent flow at end of expiration and the ineffective triggers.

Ventilator settings were adjusted to allow longer expiration by decreasing the rate to 20 per minute, and decreasing inspiratory time with I:E at 1:2.9. The volume was also increased to 450 ml.

Dynamic hyperinflation improved remarkably and now the ventilator is triggered with every inspiratory effort of the patient.

As you know, patients with severe asthma and status asthmaticus develop dynamic hyperinflation syndrome and autoPEEP meaning that the inhaled air does not get exhaled completely and the pressure is built up inside the alveoli. This is caused by not enough expiratory time due to the high time constant of the airways. My question, what will happen next if the process continues?

You may want to see this video to help you understand the concept.

47 years old female with status asthmatics who got intubated and placed on mechanical ventilation. An inspiratory hold was applied as shown in this snapshot of the ventilator screen:

Notice the limitation of the expiratory flow in the first breath before the inspiratory hold. Also notice that the peak pressure is elevated at 46 cm H2O, the plateau is elevated at 30 cm H2O and the difference is at 16 cm H2O representing the increased airway resistance due to bronchospasm.

What would you do next to confirm your diagnosis?

A study published in critical care journal investigated the predictive ability of various tests for successful weaning from mechanical ventilation and extubation in a prospective, multicenter observational study involving 367 adult patients across four intensive care units. Researchers focused on the cuff leak test, rate of rapid and shallow breathing, cough intensity (0 to 3), and diaphragmatic contraction velocity (DCV) to determine their utility in forecasting the outcome of spontaneous breathing trials (SBT) and extubation.

Key findings include:

• Out of 456 SBTs performed, the success rate was 76.5%.

• An equation for predicting SBT success was developed, combining cough intensity and DCV. With a cutoff point of ≥0.83, the prediction had a high sensitivity of 91.5% but a low specificity of 22.1%, with an overall accuracy of 76.2%. The area under the receiver operating characteristic (ROC) curve was modest at 0.63.

(0.56 × Cough) − (0.13 × DCV) + 0.25

• Another equation to predict extubation success was also created,…

Emulating Target Trials Comparing Early and Delayed Intubation Strategies

The appropriateness of initiating intubation early in critically ill patients has been a topic of contention, with previous observational studies yielding ambiguous results due to various flaws such as immortal time bias, unfitting eligibility criteria, and unrealistic treatment strategies. This study aimed to discern if treatment strategies that promote early intubation upon critical care admission enhance 30-day survival as opposed to those that advocate for delayed intubation. Leveraging data from the Medical Information Mart for Intensive Care-IV database, three target trials were emulated, each differing in treatment strategy flexibility and baseline eligibility criteria. The findings revealed that under exceedingly strict treatment strategies coupled with broad eligibility criteria, the 30-day mortality risk was 7.1 percentage points higher for early intubation than for delayed intubation (95% CI, 6.2-7.9). However, subsequent target trial emulations with more pragmatic treatment strategies and eligibility criteria displayed risk…