Tracheal intubation (TI) is a critical procedure used in emergency departments (EDs) and ICUs worldwide, though it carries significant risks, especially in resource-limited settings. Major adverse events (MAEs) like haemodynamic instability, severe hypoxaemia, and cardiac arrest are common during the peri-intubation period and are associated with worse patient outcomes. Critically ill patients often present with a physiologically difficult airway, increasing the risk of these events even without anatomical airway difficulties.
A new study found that the incidence of MAEs during emergency intubations exceeded 40% despite a high first-attempt success rate of 80%. This suggests that factors beyond anatomical challenges contribute to adverse events. Understanding the causes of these complications is crucial for improving patient outcomes globally, particularly in low- and middle-income countries (LMICs), where data on the relationship between MAEs and mortality is limited.
The Brazilian Airway Registry Cooperation (BARCO) aimed to address this gap by providing data on the incidence of MAEs and their association with 28-day mortality in critically ill patients undergoing emergency intubations in a middle-income country.
The study was conducted across 18 emergency departments in Brazil from March 2022 to April 2024. It included adults (≥ 18 years) undergoing emergency intubation, excluding those intubated electively or for cardiac arrest. Major peri-intubation adverse events were defined as severe hypoxaemia, new haemodynamic instability, or cardiac arrest occurring within 30 minutes of intubation. The primary outcome was 28-day mortality.
Among 2,846 patients, major adverse events occurred in 919 (32.3%) intubations, with new haemodynamic instability being the most common (20.0%), followed by severe hypoxaemia (12.5%) and cardiac arrest (3.5%). The overall 28-day mortality rate was 45.1%. Patients who experienced any major adverse event had a significantly higher 28-day mortality (57.6% vs. 39.2%). Sensitivity analyses confirmed these results. Successful first-attempt intubation was associated with a reduced likelihood of major adverse events.
Factors associated with MAEs included both nonmodifiable and modifiable elements, such as first-attempt success, pre-intubation haemodynamic status, and peripheral oxygen saturation.
Comparing this study to the 2021 INTUBE study, which observed a higher incidence of MAEs (45.2%) and more haemodynamic instability (42.6%), this cohort had less haemodynamic instability but more severe hypoxaemia and cardiac arrest. Differences in drug preferences and intubation practices, such as the use of propofol and opioids, reflect global variations in clinical practice.
Pre-intubation haemodynamic optimisation and oxygenation were important in reducing MAEs, though patients receiving fluids or vasopressors before intubation were more likely to experience MAEs, suggesting a more severe baseline clinical profile. Structured strategies for managing difficult airways, including assessment, stabilisation, and optimised pre-oxygenation, are essential. Factors like shock index, organ dysfunction, and vasopressor use were strongly associated with MAEs.
The study also found that first-attempt intubation success was associated with a lower risk of MAEs, and specialised training, particularly in emergency medicine, was key to improving success rates. Despite the potential benefits of videolaryngoscopy and bougies, their limited use in the cohort may have contributed to a lower first-attempt success rate (74.3%). Additionally, the choice of induction agent (e.g., etomidate vs. ketamine) remains an area for further investigation.
In conclusion, one in three patients experienced a peri-intubation major adverse event, which may increase 28-day mortality. Modifiable factors, such as first-attempt success, pre-intubation haemodynamics, pre-oxygenation, and sedative choices, could help reduce the risk of these events. The findings emphasise the urgent need for targeted interventions to minimise peri-intubation adverse events, especially in resource-constrained settings.
Source: Critical Care
Image Credit: iStock
