EBQ:A Multicenter, Randomized Trial of Ramped Position vs Sniffing Position During Endotracheal Intubation of Critically Ill Adults.

incomplete Journal Club Article
Semler MW, Janz DR, Russell DW, Casey JD, Lentz RJ, Zouk AN, deBoisblanc BP, Santanilla JI, Khan YA, Joffe AM, Stigler WS, Rice TW. "A Multicenter, Randomized Trial of Ramped Position vs Sniffing Position During Endotracheal Intubation of Critically Ill Adults.". Chest. 2017. epublished ahead of print:.
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Clinical Question

In critically ill patients, does the ramped position allow for a higher lowest arterial saturation during intubation as compared to the sniffing position?

  • Population: critically ill ICU patients
  • Intervention: ramped position during intubation
  • Comparison: sniffing position during intubation
  • Outcome: lowest SPO2%
  • Secondary outcomes:
    • Cormack-Lehane grade of glottic view
    • difficulty of intubation
    • number of laryngoscopy attempts


  • Primary outcome: The ramped position (as compared to sniffing position) did NOT improve oxygenation during endotracheal intubation in critical ICU patients.
  • Secondary outcomes:
    • The ramped position may worsen glottic view.
    • The ramped position may increase the number of laryngoscopy attempts prior to intubation

Major Points

Study Design

  • multicenter randomized control study
    • computer randomized to ramped vs. sniffing in 1:1 ratio
    • sequentially numbered opaque envelopes
  • pragmatic trial
  • written preintubation checklist: pictures provided at bedside for specific position
  • operator-reported subjective difficulty of intubation, airway complications, Cormack-Lehane
  • powered to detect 5% difference in SPO2 at α level of 0.05


  • ICU patients requiring endotracheal inbutation in four tertiary centers
    • Vanderbilt, LSU, Oschner, UAB

Patient Demographics

≥18 y.o. in ICU at 4 tertiary centers undergoing endotracheal intubation by a pulmonary/crit care fellow

Inclusion Criteria

  • ≥18 y.o.
  • ICU patient
  • intubated by pulm/crit care fellow
  • sedation and neuromuscular blockade

Exclusion Criteria

  • intubation required too urgently to obtain randomization envelope
    • cardiac arrest, respiratory arrest, post extubation stridor, massive hemoptysis/hematemesis, hemodynamic instability)
  • thought to need a specific position
    • supine for cervical instability (3)
    • ramped for ICH (1)
    • ramped for severe hypoxemia (1)
    • upright for aspiration (1)


  • ramped positioning for endotracheal intubation: ICU beds with heads electronically raised to 25°
    • patient's occiput ramped on top of mattress so that face is parallel to ceiling
    • lower half of bed parallel to floor
  • sniffing position: entire bed horizontal with blankets/towels beneath head and neck
    • neck flexion, slight head extension relative to the neck.
    • elevation of the shoulders or torso was not permitted.


Primary Outcome

  • lowest arterial oxygen saturation during intubation as measured by pulse oximetry 92% (sniffing) vs. 93% (ramped) p=0.27
    • from moment of induction until 2 minutes after intubation

Secondary Outcomes

  • Secondary outcomes all worse in ramped as compared to sniffing
    • Cormack-Lehane grade of laryngoscopic view p=0.01
    • difficulty of intubation p=0.04
    • number of laryngoscopy attempts: first pass success 76.2% (ramped) vs 85.4% (sniffing) p=0.02
  • several procedural outcomes showed advantage in sniffing position as well
    • bougie required in 19.2% (ramped) vs. 6.2% (sniffing) p=0.002
    • second laryngoscopy technique required in 16.2% (ramped) vs. 6.2% (sniffing) p=0.01

Subgroup analysis

  • Patients very similar in demographics, vasopressor use, active medical conditions, indication for intubation, recent hypoxemia, preoxygenation, and clinical outcomes
  • Operators very similar in duration of training, previous intubations,

Criticisms & Further Discussion

  • well-designed multi-center RCT showing nonsuperiority of ramp vs. sniffing position in ICU intubation
    • concealed allocation prevents selection bias
    • end points collected by blinded, independent observer, eliminating observer bias
  • previous OR trials showing improved lowest SPO2 in ramped position are in stable, surgically-cleared patients
    • this study may be more generalizable to the patients requiring intubation in the ED
  • non-patient focused 2ndary outcomes: how much do quality of view, subjective difficulty, first pass success, and procedural outcomes affect patient morbidity/mortality? Especially given the reported statistical equivalence of clinical outcomes in this trial.
  • excluded patients requiring urgent intubation
  • subjective secondary outcomes
  • fellows intubating: how generalizable are these to more experienced practitioners?
  • practitioners baseline more experienced in sniffing position: median 37 (sniffing) vs. 10 (ramped)
    • in post hoc analysis, previous experience with sniffing vs. ramped did not affect lowest SPO2 or procedural outcome

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See Also