Peri-Intubation Adverse Airway Events in Critically Ill Patients With Morbid and Super Obesity

Peri-Intubation Adverse Airway Events in Critically Ill Patients With Morbid and Super Obesity: A Retrospective Analysis

This study aims to compare the incidence and characteristics of peri-intubation adverse airway events in critically ill trauma patients with morbid obesity versus those with super obesity, and to determine whether increasing BMI independently predicts severe peri-intubation complications.

Study Overview

• Status: Not yet recruiting
• Conditions: Obesity; Airway Complication of Anesthesia; Intubation; Difficult or Failed
• Intervention / Treatment: Procedure: endotracheal intubation

Detailed Description

Obesity represents a major global health challenge, with prevalence steadily rising worldwide. Beyond its well-characterized metabolic and cardiovascular consequences, obesity poses significant challenges for airway management, particularly among critically ill patients requiring urgent tracheal intubation. The degree of obesity is clinically relevant: morbid obesity (BMI ≥40 kg/m²) is associated with anatomical and physiological alterations that markedly increase the risk of difficult airway and peri-intubation complications compared with patients with BMI <40 kg/m².

From an anatomical perspective, morbidly obese patients often present with a short, thick neck, increased cervical adiposity, and limited atlanto-occipital extension, complicating optimal positioning and glottic visualization during laryngoscopy. Redundant upper airway soft tissue, macroglossia, and higher Mallampati classes further impede mask ventilation and reduce pharyngeal patency. Secondary analyses of the international INTUBE cohort demonstrated that obese critically ill patients had a significantly higher prevalence of difficult airway predictors such as short neck, reduced mouth opening, and high Mallampati scores, compared with non-obese patients (74.3% - 35.7%, p<0.001). Similarly, in a large retrospective bariatric cohort, severe obesity independently increased the odds of difficult intubation when Cormack-Lehane grade IV (OR 8.9) or Mallampati IV (OR 5.1) were present.

Physiological derangements further compound these challenges. Elevated intra-abdominal pressure and cephalad diaphragm displacement reduce functional residual capacity (FRC) and expiratory reserve volume, leaving critically limited oxygen reserves during apnea. Increased oxygen consumption and basal metabolic rate shorten the safe apneic window, resulting in rapid desaturation if intubation is prolonged or requires multiple attempts. The INTUBE study reported that severe peri-intubation hypoxemia (SpO₂ <80%) occurred more frequently in obese versus non-obese critically ill patients (12.1% - 8.6%, p=0.01), and first-pass intubation failure strongly correlated with this complication. Even in optimized elective settings such as bariatric surgery, BMI >60 kg/m² significantly increased the risk of difficult intubation, despite high first-pass success rates (95.4%) and low complication rates.

These findings highlight that morbid obesity imposes both anatomical and physiological barriers to safe intubation. Critically ill patients with morbid obesity are uniquely vulnerable, with increased risks of failed first-pass attempts, severe hypoxemia, and potentially life-threatening complications. However, prospective evidence directly comparing peri-intubation outcomes among critically ill patients with BMI 40-50 versus ≥50 kg/m² remains limited.

While morbid obesity is an established risk factor, there is a compelling physiological rationale to suspect heterogeneity of risk within this category. Super obesity (BMI ≥50 kg/m²) may represent a distinct phenotype with more pronounced anatomical and physiological derangements. In elective bariatric populations, BMI >50 kg/m² has been linked to difficult mask ventilation and intubation, suggesting a threshold effect for extreme obesity [6]. Potential mechanisms include increased fat deposition in the neck and pharynx, further reductions in FRC, and higher prevalence of comorbidities such as obesity hypoventilation syndrome. Nonetheless, studies in elective settings remain inconclusive; for example, Mahmoud et al. found that neither super-obesity nor super-super-obesity independently predicted difficult intubation or mask ventilation, with high STOP-Bang and Mallampati scores emerging as the primary predictors.

Critically ill patients differ substantially from elective surgical populations, presenting with limited FRC, rapid desaturation during apnea, hemodynamic instability, and multiple comorbidities, which may amplify the impact of morbid and super obesity on peri-intubation outcomes. Consequently, the independent effect of BMI ≥40 kg/m² on peri-intubation complications in the ICU remains uncertain.

To address this knowledge gap, the present study was designed as the first investigation in the literature to directly compare peri-intubation adverse events between morbidly obese and super obese critically ill trauma patients.The partipicants hypothesize that super obese patients experience a higher incidence of severe peri-intubation complications compared with their morbidly obese counterparts, thereby providing novel insight into risk stratification and airway management in this high-risk population.

• Study Type: Observational
• Enrollment (Estimated): 2

Contacts and Locations

• Study Contact: Name: TOLGA SARAÇOĞLU, Prof,MD; Phone Number: +1 (904) 524-5932; Email: kemaltolgasaracoglu@gmail.com
• Study Contact Backup: Name: AYTEN Saraçoğlu, PROF,MD; Phone Number: +1 (904) 524-4331; Email: anesthesiayten@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Critically ill adult trauma patients aged 18 years and older admitted to the surgical ICU at UF Health Jacksonville between January 1, 2023, and November 1, 2025, who had a BMI ≥40 kg/m² and underwent intubation

Description

Inclusion Criteria:

• Age ≥ 18 years
• BMI ≥40
• Admission to the surgical ICU and intubated during ICU stay
• Availability of complete clinical data

Exclusion Criteria:

• Age < 18 years
• BMI<40
• No intubation
• Incomplete or missing medical records

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Group 1; Morbidly obese (BMI 40-49.9 kg/m²)	Procedure: endotracheal intubation; adult trauma patients (≥18 years) admitted to the Surgical Intensive Care Unit
Group 2; Super obese (BMI ≥50 kg/m²)	Procedure: endotracheal intubation; adult trauma patients (≥18 years) admitted to the Surgical Intensive Care Unit

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Severe hypoxemia	SpO₂ <80% during intubation	30 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Major peri-intubation complications	Severe hypotension	30 minutes
hospital mortality	rate of mortality	28 days

Collaborators and Investigators

• Sponsor: Zeliha Alicikus
• Investigators: Study Director: AYTEN SARAÇOĞLU, Prof,MD, Florida University Jacksonville

Study record dates

Study Major Dates

• Study Start (Estimated): April 23, 2026
• Primary Completion (Estimated): May 30, 2026
• Study Completion (Estimated): June 30, 2026

Study Registration Dates

• First Submitted: November 24, 2025
• First Submitted That Met QC Criteria: December 16, 2025
• First Posted (Actual): December 22, 2025

Study Record Updates

• Last Update Posted (Actual): April 14, 2026
• Last Update Submitted That Met QC Criteria: April 11, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Overweight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity; Investigative Techniques; Therapeutics; Airway Management; Intubation; Intubation, Intratracheal
• Other Study ID Numbers: AYTEN-1

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No