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

NCT ID: NCT07297420

Last Updated: 2025-12-22

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Total Enrollment: 2 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2025-12-30
• Study Completion Date: 2026-05-30

Brief Summary

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.

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.

Conditions

Obesity; Airway Complication of Anesthesia; Intubation; Difficult or Failed

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: RETROSPECTIVE

Study Groups

Group 1

Morbidly obese (BMI 40-49.9 kg/m²)

endotracheal intubation

Intervention Type: PROCEDURE

adult trauma patients (≥18 years) admitted to the Surgical Intensive Care Unit

Group 2

Super obese (BMI ≥50 kg/m²)

endotracheal intubation

Intervention Type: PROCEDURE

adult trauma patients (≥18 years) admitted to the Surgical Intensive Care Unit

Interventions

endotracheal intubation

adult trauma patients (≥18 years) admitted to the Surgical Intensive Care Unit

Intervention Type: PROCEDURE

Eligibility Criteria

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

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Zeliha Alicikus

OTHER_GOV

Sponsor Role: lead

Responsible Party

Zeliha Alicikus

Head of Anesthesiology and Reanimation department,Assoc Prof

Responsibility Role: SPONSOR_INVESTIGATOR

Principal Investigators

Ayten SARAÇOĞLU, Prof,MD

Role: STUDY_DIRECTOR

Florida University Jacksonville

Central Contacts

Ayten SARAÇOĞLU, Prof,MD

Role: CONTACT

Phone: +1 (904) 524-4331

Email: anesthesiayten@gmail.com

Tolga SARAÇOĞLU, Prof,MD

Role: CONTACT

Phone: +1 (904) 524-5932

Email: kemaltolgasaracoglu@gmail.com

Other Identifiers

AYTEN-1

Identifier Type: -

Identifier Source: org_study_id