Intubation and Extubation Practices Vary Widely Around the World

By Reuters Staff

March 24, 2021

NEW YORK (Reuters Health) - Two new studies suggest wide international variation in intubation and extubation practices and associated adverse events among critically ill patients receiving mechanical ventilation.

"Variability can only be leveraged and addressed once its existence is laid bare for all to see. By doing so, these studies serve to advance current understanding of ways to improve care for critically ill patients," Dr. Hayley Gershengorn of the University of Miami Miller School of Medicine in Florida writes in an editorial in JAMA, where both studies appear.

The INTUBE study team evaluated the incidence and nature of adverse peri-intubation events and assessed current practice of intubation in 2,964 critically ill patients (median age, 63; 63% men) undergoing tracheal intubation across 197 sites in 29 countries.

"A key finding of this study was the identification of cardiovascular instability as the most frequent adverse event following intubation," report first author Dr. Vincenzo Russotto of the University of Milano-Bicocca, in Italy, and colleagues.

The main reason for intubation in the cohort was respiratory failure (52%), followed by neurological impairment (31%) and cardiovascular instability (9.4%). Resident physicians intubated 52% of patients, and anesthesiologists intubated 54.0%.

Nearly two-thirds of patients (62%) received preoxygenation by a bag-valve mask; standard facemask was used in 13%, non-invasive ventilation in 12% and high-flow nasal cannula in 5%.

Sixty-two percent of patients underwent rapid-sequence induction (i.e., no ventilation between induction and laryngoscopy).

The investigators note that he role of video laryngoscopy to facilitate tracheal intubation in critically ill patients "remains unclear" and it was used in only 505 patients (17%).

While ketamine and etomidate have been recommended as the induction agent of choice for intubation of critically ill patients, they were seldom used, with propofol still representing the most commonly used induction agent, the team found.

Also noteworthy, say the researchers, was the low use of waveform capnography (35%) as standard monitoring during tracheal intubation. "In 68.9% of patients with tracheal tube accidentally placed in the esophagus, waveform capnography was not in place, so clinicians relied on inaccurate clinical signs such as auscultation or chest movement for detection of esophageal intubation," Dr. Russotto and colleagues report.

They further report that 45% of all patients experienced at least one major adverse peri-intubation event, most commonly cardiovascular instability, which occurred in 43% of all patients undergoing emergency intubation, followed by severe hypoxemia (9%) and cardiac arrest (3%). Overall ICU mortality was 33%.

Successful intubation on the first try was achieved in 80% of patients.

The rate of major adverse events was significantly lower with first-pass intubation success than it was for patients requiring two attempts (43% vs. 52%) and for patients requiring three or more attempts (43% vs. 58%).

The need for multiple intubation attempts increased the risk of severe hypoxia and cardiac arrest. First-pass intubation success was more common among staff physicians and anesthesiologists than residents and other clinicians with different specialty backgrounds, the researchers found.

The other study identified variation in how patients are weaned off invasive mechanical ventilation across different countries, with regard to the protocols used, screening for and conducting spontaneous breathing trials (SBTs), adjustment of ventilator support, and the responsibility of clinicians involved in weaning.

The findings of Dr. Karen Burns with Unity Health Toronto, St Michael's Hospital, in Canada, and colleagues are based on 1,868 critically ill patients (median age, 62; 63% men) who received invasive mechanical ventilation for at least 24 hours in 142 intensive-care units (ICUs) in Canada, Europe, the U.S., India, the U.K. and Australia/New Zealand.

Among the key findings:

- Nearly 50% of patients underwent an initial SBT, of which more than 80% were successful.

- An initial SBT (vs. direct extubation) was associated with higher ICU mortality and longer duration of ventilation and ICU stay.

- Failing the initial SBT (vs. passing the initial SBT) was associated with higher ICU mortality, longer duration of ventilation, longer ICU stay, and greater likelihood of still receiving ventilation and being in the ICU at day 28.

- Undergoing a later (vs. earlier) initial SBT was associated with longer duration of ventilation, longer ICU and hospital stays, and greater likelihood of still receiving ventilation and being in the ICU at day 28.

- Most patients were screened once daily to identify candidates for SBT, and were less often screened twice daily or more frequently.

- Having written directives to guide care during weaning and the roles played by available clinicians varied widely by region.

- T-piece SBTs were more common in India and Europe; pressure support with positive end-expiratory pressure (PEEP) SBTs were more common in Canada, the U.K., the U.S., and Australia/New Zealand.

In her editorial, Dr. Gershengorn makes the point that variation in many practices is well known to exist in critical care globally and within countries, states and even ICUs.

"Some degree of variability (even within relatively homogeneous patient groups) is appropriate based on patient-specific differences. Similarly, it is easy to understand why too much variability is suboptimal; if two identical patients are admitted under the care of two different physicians, the treatment they receive should not vary meaningfully. It can be challenging, however, to determine how much variability is appropriate," Dr. Gershengorn, who specializes in critical-care medicine, points out.

These two studies "represent ambitious large-scale data collection efforts that provide a window into international care variability involving intubation and extubation practices and adverse events among patients who received invasive mechanical ventilation," she concludes.

SOURCE: and JAMA, online March 23, 2021.