Related Experiment Video
Updated: Aug 16, 2026

Preoxygenation Techniques for Tracheal Intubation in Critically Ill Adults Utilizing Oxygen Mask and Noninvasive Ventilation
Published on: December 5, 2025
Ventilation patterns in patients with severe traumatic brain injury following paramedic rapid sequence intubation
Daniel P Davis1, Robyn Heister, Jennifer C Poste
1Department of Emergency Medicine, University of California-San Diego, San Diego, CA, USA. davismd@cox.net
Introduction:
Inadvertent hyperventilation has been documented during aeromedical transports but has not been studied following paramedic rapid sequence intubation (RSI). The San Diego Paramedic RSI Trial was designed to study the impact of paramedic RSI on outcome in patients with severe head injury. This analysis explores ventilation patterns in a cohort of trial patients undergoing end-tidal CO2 (ETCO2) monitoring.
Methods:
Adult patients with severe head injury (Glasgow Coma Score: 3-8) unable to be intubated without RSI were prospectively enrolled in the trial. Midazolam and succinylcholine were used for RSI; rocuronium was administered following tube confirmation. Standardized ventilation protocols were used by most paramedics; however, one agency instituted ETCO2 monitoring during the second trial year, with paramedics instructed to target ETCO2 values of 30 to 35 mmHg. The incidence and duration of inadvertent hyperventilation (ETCO2: <30 mmHg) and severe hyperventilation (ETCO2: <25 mmHg) were explored for patients undergoing ETCO2 monitoring. The initial, final, minimum, and maximum values for ETCO2 and the maximum and minimum ventilatory rate values were also calculated using descriptive statistics (95% confidence interval). The pattern of ETCO2 values over time and distribution of recorded ventilatory rate values were explored graphically.
Results:
A total of 76 trial patients had adequate ETCO2 data for this analysis. The mean values for initial, final, maximum, and minimum ETCO2 were 40.8 (range: 37.5-44.2), 28.4 (range: 25.4-31.4), 45.1 (range: 41.4-48.8), and 23.5 mmHg (range: 21.4-25.5), respectively. The mean maximum and minimum ventilatory rate values were 36.0/minute (range: 33.5-38.5) and 12.8/minute (range: 11.9-13.7), respectively. ETCO2 values less than 30 and 25 mmHg were documented in 79% and 59% of patients, respectively, with mean durations of 485 (range: 378-592) and 390 seconds (range: 285-494).
Conclusion:
Inadvertent hyperventilation is common following paramedic RSI, despite ETCO2 monitoring and target parameters.
Related Concept Videos
Cardiopulmonary Resuscitation II: ACLS Airway Management
Cardiopulmonary Resuscitation V: Advanced Airway Management Techniques
Endotracheal Tube Extubation
Procedure
Extubation removes the endotracheal tube (ETT) from the patient on mechanical ventilation. It requires a well-coordinated, multidisciplinary approach involving physicians, nurses, respiratory therapists, and other healthcare professionals.
Mechanical Ventilation II: Invasive Ventilation
Negative-Pressure Ventilators
Negative-pressure ventilators create a vacuum around the chest or body to draw air into the lungs, simulating breathing. This method does not require an...
Alterations in Respiration II
In Biot's breathing, the respiratory rate and depth are irregular, alternating between periods of deep gasping and apnea. Common causes include...
Acute Respiratory Failure-IV
